diff -druNp --no-dereference linux-libre-5.4-gnu/arch/powerpc/include/asm/asm-prototypes.h linux-libre-5.4.1-gnu/arch/powerpc/include/asm/asm-prototypes.h
--- linux-libre-5.4-gnu/arch/powerpc/include/asm/asm-prototypes.h	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/powerpc/include/asm/asm-prototypes.h	2019-11-29 04:10:32.000000000 -0500
@@ -152,9 +152,12 @@ void _kvmppc_save_tm_pr(struct kvm_vcpu
 /* Patch sites */
 extern s32 patch__call_flush_count_cache;
 extern s32 patch__flush_count_cache_return;
+extern s32 patch__flush_link_stack_return;
+extern s32 patch__call_kvm_flush_link_stack;
 extern s32 patch__memset_nocache, patch__memcpy_nocache;
 
 extern long flush_count_cache;
+extern long kvm_flush_link_stack;
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 void kvmppc_save_tm_hv(struct kvm_vcpu *vcpu, u64 msr, bool preserve_nv);
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/powerpc/include/asm/security_features.h linux-libre-5.4.1-gnu/arch/powerpc/include/asm/security_features.h
--- linux-libre-5.4-gnu/arch/powerpc/include/asm/security_features.h	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/powerpc/include/asm/security_features.h	2019-11-29 04:10:32.000000000 -0500
@@ -81,6 +81,9 @@ static inline bool security_ftr_enabled(
 // Software required to flush count cache on context switch
 #define SEC_FTR_FLUSH_COUNT_CACHE	0x0000000000000400ull
 
+// Software required to flush link stack on context switch
+#define SEC_FTR_FLUSH_LINK_STACK	0x0000000000001000ull
+
 
 // Features enabled by default
 #define SEC_FTR_DEFAULT \
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/powerpc/kernel/entry_64.S linux-libre-5.4.1-gnu/arch/powerpc/kernel/entry_64.S
--- linux-libre-5.4-gnu/arch/powerpc/kernel/entry_64.S	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/powerpc/kernel/entry_64.S	2019-11-29 04:10:32.000000000 -0500
@@ -537,6 +537,7 @@ flush_count_cache:
 	/* Save LR into r9 */
 	mflr	r9
 
+	// Flush the link stack
 	.rept 64
 	bl	.+4
 	.endr
@@ -546,6 +547,11 @@ flush_count_cache:
 	.balign 32
 	/* Restore LR */
 1:	mtlr	r9
+
+	// If we're just flushing the link stack, return here
+3:	nop
+	patch_site 3b patch__flush_link_stack_return
+
 	li	r9,0x7fff
 	mtctr	r9
 
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/powerpc/kernel/security.c linux-libre-5.4.1-gnu/arch/powerpc/kernel/security.c
--- linux-libre-5.4-gnu/arch/powerpc/kernel/security.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/powerpc/kernel/security.c	2019-11-29 04:10:32.000000000 -0500
@@ -24,6 +24,7 @@ enum count_cache_flush_type {
 	COUNT_CACHE_FLUSH_HW	= 0x4,
 };
 static enum count_cache_flush_type count_cache_flush_type = COUNT_CACHE_FLUSH_NONE;
+static bool link_stack_flush_enabled;
 
 bool barrier_nospec_enabled;
 static bool no_nospec;
@@ -212,11 +213,19 @@ ssize_t cpu_show_spectre_v2(struct devic
 
 		if (ccd)
 			seq_buf_printf(&s, "Indirect branch cache disabled");
+
+		if (link_stack_flush_enabled)
+			seq_buf_printf(&s, ", Software link stack flush");
+
 	} else if (count_cache_flush_type != COUNT_CACHE_FLUSH_NONE) {
 		seq_buf_printf(&s, "Mitigation: Software count cache flush");
 
 		if (count_cache_flush_type == COUNT_CACHE_FLUSH_HW)
 			seq_buf_printf(&s, " (hardware accelerated)");
+
+		if (link_stack_flush_enabled)
+			seq_buf_printf(&s, ", Software link stack flush");
+
 	} else if (btb_flush_enabled) {
 		seq_buf_printf(&s, "Mitigation: Branch predictor state flush");
 	} else {
@@ -377,18 +386,49 @@ static __init int stf_barrier_debugfs_in
 device_initcall(stf_barrier_debugfs_init);
 #endif /* CONFIG_DEBUG_FS */
 
+static void no_count_cache_flush(void)
+{
+	count_cache_flush_type = COUNT_CACHE_FLUSH_NONE;
+	pr_info("count-cache-flush: software flush disabled.\n");
+}
+
 static void toggle_count_cache_flush(bool enable)
 {
-	if (!enable || !security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE)) {
+	if (!security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE) &&
+	    !security_ftr_enabled(SEC_FTR_FLUSH_LINK_STACK))
+		enable = false;
+
+	if (!enable) {
 		patch_instruction_site(&patch__call_flush_count_cache, PPC_INST_NOP);
-		count_cache_flush_type = COUNT_CACHE_FLUSH_NONE;
-		pr_info("count-cache-flush: software flush disabled.\n");
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+		patch_instruction_site(&patch__call_kvm_flush_link_stack, PPC_INST_NOP);
+#endif
+		pr_info("link-stack-flush: software flush disabled.\n");
+		link_stack_flush_enabled = false;
+		no_count_cache_flush();
 		return;
 	}
 
+	// This enables the branch from _switch to flush_count_cache
 	patch_branch_site(&patch__call_flush_count_cache,
 			  (u64)&flush_count_cache, BRANCH_SET_LINK);
 
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	// This enables the branch from guest_exit_cont to kvm_flush_link_stack
+	patch_branch_site(&patch__call_kvm_flush_link_stack,
+			  (u64)&kvm_flush_link_stack, BRANCH_SET_LINK);
+#endif
+
+	pr_info("link-stack-flush: software flush enabled.\n");
+	link_stack_flush_enabled = true;
+
+	// If we just need to flush the link stack, patch an early return
+	if (!security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE)) {
+		patch_instruction_site(&patch__flush_link_stack_return, PPC_INST_BLR);
+		no_count_cache_flush();
+		return;
+	}
+
 	if (!security_ftr_enabled(SEC_FTR_BCCTR_FLUSH_ASSIST)) {
 		count_cache_flush_type = COUNT_CACHE_FLUSH_SW;
 		pr_info("count-cache-flush: full software flush sequence enabled.\n");
@@ -407,11 +447,20 @@ void setup_count_cache_flush(void)
 	if (no_spectrev2 || cpu_mitigations_off()) {
 		if (security_ftr_enabled(SEC_FTR_BCCTRL_SERIALISED) ||
 		    security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED))
-			pr_warn("Spectre v2 mitigations not under software control, can't disable\n");
+			pr_warn("Spectre v2 mitigations not fully under software control, can't disable\n");
 
 		enable = false;
 	}
 
+	/*
+	 * There's no firmware feature flag/hypervisor bit to tell us we need to
+	 * flush the link stack on context switch. So we set it here if we see
+	 * either of the Spectre v2 mitigations that aim to protect userspace.
+	 */
+	if (security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED) ||
+	    security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE))
+		security_ftr_set(SEC_FTR_FLUSH_LINK_STACK);
+
 	toggle_count_cache_flush(enable);
 }
 
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/powerpc/kvm/book3s_hv_rmhandlers.S linux-libre-5.4.1-gnu/arch/powerpc/kvm/book3s_hv_rmhandlers.S
--- linux-libre-5.4-gnu/arch/powerpc/kvm/book3s_hv_rmhandlers.S	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/powerpc/kvm/book3s_hv_rmhandlers.S	2019-11-29 04:10:32.000000000 -0500
@@ -11,6 +11,7 @@
  */
 
 #include <asm/ppc_asm.h>
+#include <asm/code-patching-asm.h>
 #include <asm/kvm_asm.h>
 #include <asm/reg.h>
 #include <asm/mmu.h>
@@ -1487,6 +1488,13 @@ guest_exit_cont:		/* r9 = vcpu, r12 = tr
 1:
 #endif /* CONFIG_KVM_XICS */
 
+	/*
+	 * Possibly flush the link stack here, before we do a blr in
+	 * guest_exit_short_path.
+	 */
+1:	nop
+	patch_site 1b patch__call_kvm_flush_link_stack
+
 	/* If we came in through the P9 short path, go back out to C now */
 	lwz	r0, STACK_SLOT_SHORT_PATH(r1)
 	cmpwi	r0, 0
@@ -1963,6 +1971,28 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	mtlr	r0
 	blr
 
+.balign 32
+.global kvm_flush_link_stack
+kvm_flush_link_stack:
+	/* Save LR into r0 */
+	mflr	r0
+
+	/* Flush the link stack. On Power8 it's up to 32 entries in size. */
+	.rept 32
+	bl	.+4
+	.endr
+
+	/* And on Power9 it's up to 64. */
+BEGIN_FTR_SECTION
+	.rept 32
+	bl	.+4
+	.endr
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
+
+	/* Restore LR */
+	mtlr	r0
+	blr
+
 kvmppc_guest_external:
 	/* External interrupt, first check for host_ipi. If this is
 	 * set, we know the host wants us out so let's do it now
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/x86/entry/entry_32.S linux-libre-5.4.1-gnu/arch/x86/entry/entry_32.S
--- linux-libre-5.4-gnu/arch/x86/entry/entry_32.S	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/x86/entry/entry_32.S	2019-11-29 04:10:32.000000000 -0500
@@ -172,7 +172,7 @@
 	ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI
 	.if \no_user_check == 0
 	/* coming from usermode? */
-	testl	$SEGMENT_RPL_MASK, PT_CS(%esp)
+	testl	$USER_SEGMENT_RPL_MASK, PT_CS(%esp)
 	jz	.Lend_\@
 	.endif
 	/* On user-cr3? */
@@ -205,64 +205,76 @@
 #define CS_FROM_ENTRY_STACK	(1 << 31)
 #define CS_FROM_USER_CR3	(1 << 30)
 #define CS_FROM_KERNEL		(1 << 29)
+#define CS_FROM_ESPFIX		(1 << 28)
 
 .macro FIXUP_FRAME
 	/*
 	 * The high bits of the CS dword (__csh) are used for CS_FROM_*.
 	 * Clear them in case hardware didn't do this for us.
 	 */
-	andl	$0x0000ffff, 3*4(%esp)
+	andl	$0x0000ffff, 4*4(%esp)
 
 #ifdef CONFIG_VM86
-	testl	$X86_EFLAGS_VM, 4*4(%esp)
+	testl	$X86_EFLAGS_VM, 5*4(%esp)
 	jnz	.Lfrom_usermode_no_fixup_\@
 #endif
-	testl	$SEGMENT_RPL_MASK, 3*4(%esp)
+	testl	$USER_SEGMENT_RPL_MASK, 4*4(%esp)
 	jnz	.Lfrom_usermode_no_fixup_\@
 
-	orl	$CS_FROM_KERNEL, 3*4(%esp)
+	orl	$CS_FROM_KERNEL, 4*4(%esp)
 
 	/*
 	 * When we're here from kernel mode; the (exception) stack looks like:
 	 *
-	 *  5*4(%esp) - <previous context>
-	 *  4*4(%esp) - flags
-	 *  3*4(%esp) - cs
-	 *  2*4(%esp) - ip
-	 *  1*4(%esp) - orig_eax
-	 *  0*4(%esp) - gs / function
+	 *  6*4(%esp) - <previous context>
+	 *  5*4(%esp) - flags
+	 *  4*4(%esp) - cs
+	 *  3*4(%esp) - ip
+	 *  2*4(%esp) - orig_eax
+	 *  1*4(%esp) - gs / function
+	 *  0*4(%esp) - fs
 	 *
 	 * Lets build a 5 entry IRET frame after that, such that struct pt_regs
 	 * is complete and in particular regs->sp is correct. This gives us
-	 * the original 5 enties as gap:
+	 * the original 6 enties as gap:
 	 *
-	 * 12*4(%esp) - <previous context>
-	 * 11*4(%esp) - gap / flags
-	 * 10*4(%esp) - gap / cs
-	 *  9*4(%esp) - gap / ip
-	 *  8*4(%esp) - gap / orig_eax
-	 *  7*4(%esp) - gap / gs / function
-	 *  6*4(%esp) - ss
-	 *  5*4(%esp) - sp
-	 *  4*4(%esp) - flags
-	 *  3*4(%esp) - cs
-	 *  2*4(%esp) - ip
-	 *  1*4(%esp) - orig_eax
-	 *  0*4(%esp) - gs / function
+	 * 14*4(%esp) - <previous context>
+	 * 13*4(%esp) - gap / flags
+	 * 12*4(%esp) - gap / cs
+	 * 11*4(%esp) - gap / ip
+	 * 10*4(%esp) - gap / orig_eax
+	 *  9*4(%esp) - gap / gs / function
+	 *  8*4(%esp) - gap / fs
+	 *  7*4(%esp) - ss
+	 *  6*4(%esp) - sp
+	 *  5*4(%esp) - flags
+	 *  4*4(%esp) - cs
+	 *  3*4(%esp) - ip
+	 *  2*4(%esp) - orig_eax
+	 *  1*4(%esp) - gs / function
+	 *  0*4(%esp) - fs
 	 */
 
 	pushl	%ss		# ss
 	pushl	%esp		# sp (points at ss)
-	addl	$6*4, (%esp)	# point sp back at the previous context
-	pushl	6*4(%esp)	# flags
-	pushl	6*4(%esp)	# cs
-	pushl	6*4(%esp)	# ip
-	pushl	6*4(%esp)	# orig_eax
-	pushl	6*4(%esp)	# gs / function
+	addl	$7*4, (%esp)	# point sp back at the previous context
+	pushl	7*4(%esp)	# flags
+	pushl	7*4(%esp)	# cs
+	pushl	7*4(%esp)	# ip
+	pushl	7*4(%esp)	# orig_eax
+	pushl	7*4(%esp)	# gs / function
+	pushl	7*4(%esp)	# fs
 .Lfrom_usermode_no_fixup_\@:
 .endm
 
 .macro IRET_FRAME
+	/*
+	 * We're called with %ds, %es, %fs, and %gs from the interrupted
+	 * frame, so we shouldn't use them.  Also, we may be in ESPFIX
+	 * mode and therefore have a nonzero SS base and an offset ESP,
+	 * so any attempt to access the stack needs to use SS.  (except for
+	 * accesses through %esp, which automatically use SS.)
+	 */
 	testl $CS_FROM_KERNEL, 1*4(%esp)
 	jz .Lfinished_frame_\@
 
@@ -276,31 +288,40 @@
 	movl	5*4(%esp), %eax		# (modified) regs->sp
 
 	movl	4*4(%esp), %ecx		# flags
-	movl	%ecx, -4(%eax)
+	movl	%ecx, %ss:-1*4(%eax)
 
 	movl	3*4(%esp), %ecx		# cs
 	andl	$0x0000ffff, %ecx
-	movl	%ecx, -8(%eax)
+	movl	%ecx, %ss:-2*4(%eax)
 
 	movl	2*4(%esp), %ecx		# ip
-	movl	%ecx, -12(%eax)
+	movl	%ecx, %ss:-3*4(%eax)
 
 	movl	1*4(%esp), %ecx		# eax
-	movl	%ecx, -16(%eax)
+	movl	%ecx, %ss:-4*4(%eax)
 
 	popl	%ecx
-	lea	-16(%eax), %esp
+	lea	-4*4(%eax), %esp
 	popl	%eax
 .Lfinished_frame_\@:
 .endm
 
-.macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0 skip_gs=0
+.macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0 skip_gs=0 unwind_espfix=0
 	cld
 .if \skip_gs == 0
 	PUSH_GS
 .endif
-	FIXUP_FRAME
 	pushl	%fs
+
+	pushl	%eax
+	movl	$(__KERNEL_PERCPU), %eax
+	movl	%eax, %fs
+.if \unwind_espfix > 0
+	UNWIND_ESPFIX_STACK
+.endif
+	popl	%eax
+
+	FIXUP_FRAME
 	pushl	%es
 	pushl	%ds
 	pushl	\pt_regs_ax
@@ -313,8 +334,6 @@
 	movl	$(__USER_DS), %edx
 	movl	%edx, %ds
 	movl	%edx, %es
-	movl	$(__KERNEL_PERCPU), %edx
-	movl	%edx, %fs
 .if \skip_gs == 0
 	SET_KERNEL_GS %edx
 .endif
@@ -324,8 +343,8 @@
 .endif
 .endm
 
-.macro SAVE_ALL_NMI cr3_reg:req
-	SAVE_ALL
+.macro SAVE_ALL_NMI cr3_reg:req unwind_espfix=0
+	SAVE_ALL unwind_espfix=\unwind_espfix
 
 	BUG_IF_WRONG_CR3
 
@@ -357,6 +376,7 @@
 2:	popl	%es
 3:	popl	%fs
 	POP_GS \pop
+	IRET_FRAME
 .pushsection .fixup, "ax"
 4:	movl	$0, (%esp)
 	jmp	1b
@@ -395,7 +415,8 @@
 
 .macro CHECK_AND_APPLY_ESPFIX
 #ifdef CONFIG_X86_ESPFIX32
-#define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + (GDT_ENTRY_ESPFIX_SS * 8)
+#define GDT_ESPFIX_OFFSET (GDT_ENTRY_ESPFIX_SS * 8)
+#define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + GDT_ESPFIX_OFFSET
 
 	ALTERNATIVE	"jmp .Lend_\@", "", X86_BUG_ESPFIX
 
@@ -1075,7 +1096,6 @@ restore_all:
 	/* Restore user state */
 	RESTORE_REGS pop=4			# skip orig_eax/error_code
 .Lirq_return:
-	IRET_FRAME
 	/*
 	 * ARCH_HAS_MEMBARRIER_SYNC_CORE rely on IRET core serialization
 	 * when returning from IPI handler and when returning from
@@ -1128,30 +1148,43 @@ ENDPROC(entry_INT80_32)
  * We can't call C functions using the ESPFIX stack. This code reads
  * the high word of the segment base from the GDT and swiches to the
  * normal stack and adjusts ESP with the matching offset.
+ *
+ * We might be on user CR3 here, so percpu data is not mapped and we can't
+ * access the GDT through the percpu segment.  Instead, use SGDT to find
+ * the cpu_entry_area alias of the GDT.
  */
 #ifdef CONFIG_X86_ESPFIX32
 	/* fixup the stack */
-	mov	GDT_ESPFIX_SS + 4, %al /* bits 16..23 */
-	mov	GDT_ESPFIX_SS + 7, %ah /* bits 24..31 */
+	pushl	%ecx
+	subl	$2*4, %esp
+	sgdt	(%esp)
+	movl	2(%esp), %ecx				/* GDT address */
+	/*
+	 * Careful: ECX is a linear pointer, so we need to force base
+	 * zero.  %cs is the only known-linear segment we have right now.
+	 */
+	mov	%cs:GDT_ESPFIX_OFFSET + 4(%ecx), %al	/* bits 16..23 */
+	mov	%cs:GDT_ESPFIX_OFFSET + 7(%ecx), %ah	/* bits 24..31 */
 	shl	$16, %eax
+	addl	$2*4, %esp
+	popl	%ecx
 	addl	%esp, %eax			/* the adjusted stack pointer */
 	pushl	$__KERNEL_DS
 	pushl	%eax
 	lss	(%esp), %esp			/* switch to the normal stack segment */
 #endif
 .endm
+
 .macro UNWIND_ESPFIX_STACK
+	/* It's safe to clobber %eax, all other regs need to be preserved */
 #ifdef CONFIG_X86_ESPFIX32
 	movl	%ss, %eax
 	/* see if on espfix stack */
 	cmpw	$__ESPFIX_SS, %ax
-	jne	27f
-	movl	$__KERNEL_DS, %eax
-	movl	%eax, %ds
-	movl	%eax, %es
+	jne	.Lno_fixup_\@
 	/* switch to normal stack */
 	FIXUP_ESPFIX_STACK
-27:
+.Lno_fixup_\@:
 #endif
 .endm
 
@@ -1341,11 +1374,6 @@ END(spurious_interrupt_bug)
 
 #ifdef CONFIG_XEN_PV
 ENTRY(xen_hypervisor_callback)
-	pushl	$-1				/* orig_ax = -1 => not a system call */
-	SAVE_ALL
-	ENCODE_FRAME_POINTER
-	TRACE_IRQS_OFF
-
 	/*
 	 * Check to see if we got the event in the critical
 	 * region in xen_iret_direct, after we've reenabled
@@ -1353,16 +1381,17 @@ ENTRY(xen_hypervisor_callback)
 	 * iret instruction's behaviour where it delivers a
 	 * pending interrupt when enabling interrupts:
 	 */
-	movl	PT_EIP(%esp), %eax
-	cmpl	$xen_iret_start_crit, %eax
+	cmpl	$xen_iret_start_crit, (%esp)
 	jb	1f
-	cmpl	$xen_iret_end_crit, %eax
+	cmpl	$xen_iret_end_crit, (%esp)
 	jae	1f
-
-	jmp	xen_iret_crit_fixup
-
-ENTRY(xen_do_upcall)
-1:	mov	%esp, %eax
+	call	xen_iret_crit_fixup
+1:
+	pushl	$-1				/* orig_ax = -1 => not a system call */
+	SAVE_ALL
+	ENCODE_FRAME_POINTER
+	TRACE_IRQS_OFF
+	mov	%esp, %eax
 	call	xen_evtchn_do_upcall
 #ifndef CONFIG_PREEMPTION
 	call	xen_maybe_preempt_hcall
@@ -1449,10 +1478,9 @@ END(page_fault)
 
 common_exception_read_cr2:
 	/* the function address is in %gs's slot on the stack */
-	SAVE_ALL switch_stacks=1 skip_gs=1
+	SAVE_ALL switch_stacks=1 skip_gs=1 unwind_espfix=1
 
 	ENCODE_FRAME_POINTER
-	UNWIND_ESPFIX_STACK
 
 	/* fixup %gs */
 	GS_TO_REG %ecx
@@ -1474,9 +1502,8 @@ END(common_exception_read_cr2)
 
 common_exception:
 	/* the function address is in %gs's slot on the stack */
-	SAVE_ALL switch_stacks=1 skip_gs=1
+	SAVE_ALL switch_stacks=1 skip_gs=1 unwind_espfix=1
 	ENCODE_FRAME_POINTER
-	UNWIND_ESPFIX_STACK
 
 	/* fixup %gs */
 	GS_TO_REG %ecx
@@ -1515,6 +1542,10 @@ ENTRY(nmi)
 	ASM_CLAC
 
 #ifdef CONFIG_X86_ESPFIX32
+	/*
+	 * ESPFIX_SS is only ever set on the return to user path
+	 * after we've switched to the entry stack.
+	 */
 	pushl	%eax
 	movl	%ss, %eax
 	cmpw	$__ESPFIX_SS, %ax
@@ -1550,6 +1581,11 @@ ENTRY(nmi)
 	movl	%ebx, %esp
 
 .Lnmi_return:
+#ifdef CONFIG_X86_ESPFIX32
+	testl	$CS_FROM_ESPFIX, PT_CS(%esp)
+	jnz	.Lnmi_from_espfix
+#endif
+
 	CHECK_AND_APPLY_ESPFIX
 	RESTORE_ALL_NMI cr3_reg=%edi pop=4
 	jmp	.Lirq_return
@@ -1557,23 +1593,42 @@ ENTRY(nmi)
 #ifdef CONFIG_X86_ESPFIX32
 .Lnmi_espfix_stack:
 	/*
-	 * create the pointer to lss back
+	 * Create the pointer to LSS back
 	 */
 	pushl	%ss
 	pushl	%esp
 	addl	$4, (%esp)
-	/* copy the iret frame of 12 bytes */
-	.rept 3
-	pushl	16(%esp)
-	.endr
-	pushl	%eax
-	SAVE_ALL_NMI cr3_reg=%edi
+
+	/* Copy the (short) IRET frame */
+	pushl	4*4(%esp)	# flags
+	pushl	4*4(%esp)	# cs
+	pushl	4*4(%esp)	# ip
+
+	pushl	%eax		# orig_ax
+
+	SAVE_ALL_NMI cr3_reg=%edi unwind_espfix=1
 	ENCODE_FRAME_POINTER
-	FIXUP_ESPFIX_STACK			# %eax == %esp
+
+	/* clear CS_FROM_KERNEL, set CS_FROM_ESPFIX */
+	xorl	$(CS_FROM_ESPFIX | CS_FROM_KERNEL), PT_CS(%esp)
+
 	xorl	%edx, %edx			# zero error code
-	call	do_nmi
+	movl	%esp, %eax			# pt_regs pointer
+	jmp	.Lnmi_from_sysenter_stack
+
+.Lnmi_from_espfix:
 	RESTORE_ALL_NMI cr3_reg=%edi
-	lss	12+4(%esp), %esp		# back to espfix stack
+	/*
+	 * Because we cleared CS_FROM_KERNEL, IRET_FRAME 'forgot' to
+	 * fix up the gap and long frame:
+	 *
+	 *  3 - original frame	(exception)
+	 *  2 - ESPFIX block	(above)
+	 *  6 - gap		(FIXUP_FRAME)
+	 *  5 - long frame	(FIXUP_FRAME)
+	 *  1 - orig_ax
+	 */
+	lss	(1+5+6)*4(%esp), %esp			# back to espfix stack
 	jmp	.Lirq_return
 #endif
 END(nmi)
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/x86/include/asm/cpu_entry_area.h linux-libre-5.4.1-gnu/arch/x86/include/asm/cpu_entry_area.h
--- linux-libre-5.4-gnu/arch/x86/include/asm/cpu_entry_area.h	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/x86/include/asm/cpu_entry_area.h	2019-11-29 04:10:32.000000000 -0500
@@ -78,8 +78,12 @@ struct cpu_entry_area {
 
 	/*
 	 * The GDT is just below entry_stack and thus serves (on x86_64) as
-	 * a a read-only guard page.
+	 * a read-only guard page. On 32-bit the GDT must be writeable, so
+	 * it needs an extra guard page.
 	 */
+#ifdef CONFIG_X86_32
+	char guard_entry_stack[PAGE_SIZE];
+#endif
 	struct entry_stack_page entry_stack_page;
 
 	/*
@@ -94,7 +98,6 @@ struct cpu_entry_area {
 	 */
 	struct cea_exception_stacks estacks;
 #endif
-#ifdef CONFIG_CPU_SUP_INTEL
 	/*
 	 * Per CPU debug store for Intel performance monitoring. Wastes a
 	 * full page at the moment.
@@ -105,11 +108,13 @@ struct cpu_entry_area {
 	 * Reserve enough fixmap PTEs.
 	 */
 	struct debug_store_buffers cpu_debug_buffers;
-#endif
 };
 
-#define CPU_ENTRY_AREA_SIZE	(sizeof(struct cpu_entry_area))
-#define CPU_ENTRY_AREA_TOT_SIZE	(CPU_ENTRY_AREA_SIZE * NR_CPUS)
+#define CPU_ENTRY_AREA_SIZE		(sizeof(struct cpu_entry_area))
+#define CPU_ENTRY_AREA_ARRAY_SIZE	(CPU_ENTRY_AREA_SIZE * NR_CPUS)
+
+/* Total size includes the readonly IDT mapping page as well: */
+#define CPU_ENTRY_AREA_TOTAL_SIZE	(CPU_ENTRY_AREA_ARRAY_SIZE + PAGE_SIZE)
 
 DECLARE_PER_CPU(struct cpu_entry_area *, cpu_entry_area);
 DECLARE_PER_CPU(struct cea_exception_stacks *, cea_exception_stacks);
@@ -117,13 +122,14 @@ DECLARE_PER_CPU(struct cea_exception_sta
 extern void setup_cpu_entry_areas(void);
 extern void cea_set_pte(void *cea_vaddr, phys_addr_t pa, pgprot_t flags);
 
+/* Single page reserved for the readonly IDT mapping: */
 #define	CPU_ENTRY_AREA_RO_IDT		CPU_ENTRY_AREA_BASE
 #define CPU_ENTRY_AREA_PER_CPU		(CPU_ENTRY_AREA_RO_IDT + PAGE_SIZE)
 
 #define CPU_ENTRY_AREA_RO_IDT_VADDR	((void *)CPU_ENTRY_AREA_RO_IDT)
 
 #define CPU_ENTRY_AREA_MAP_SIZE			\
-	(CPU_ENTRY_AREA_PER_CPU + CPU_ENTRY_AREA_TOT_SIZE - CPU_ENTRY_AREA_BASE)
+	(CPU_ENTRY_AREA_PER_CPU + CPU_ENTRY_AREA_ARRAY_SIZE - CPU_ENTRY_AREA_BASE)
 
 extern struct cpu_entry_area *get_cpu_entry_area(int cpu);
 
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/x86/include/asm/pgtable_32_types.h linux-libre-5.4.1-gnu/arch/x86/include/asm/pgtable_32_types.h
--- linux-libre-5.4-gnu/arch/x86/include/asm/pgtable_32_types.h	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/x86/include/asm/pgtable_32_types.h	2019-11-29 04:10:32.000000000 -0500
@@ -44,11 +44,11 @@ extern bool __vmalloc_start_set; /* set
  * Define this here and validate with BUILD_BUG_ON() in pgtable_32.c
  * to avoid include recursion hell
  */
-#define CPU_ENTRY_AREA_PAGES	(NR_CPUS * 40)
+#define CPU_ENTRY_AREA_PAGES	(NR_CPUS * 39)
 
-#define CPU_ENTRY_AREA_BASE						\
-	((FIXADDR_TOT_START - PAGE_SIZE * (CPU_ENTRY_AREA_PAGES + 1))   \
-	 & PMD_MASK)
+/* The +1 is for the readonly IDT page: */
+#define CPU_ENTRY_AREA_BASE	\
+	((FIXADDR_TOT_START - PAGE_SIZE*(CPU_ENTRY_AREA_PAGES+1)) & PMD_MASK)
 
 #define LDT_BASE_ADDR		\
 	((CPU_ENTRY_AREA_BASE - PAGE_SIZE) & PMD_MASK)
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/x86/include/asm/segment.h linux-libre-5.4.1-gnu/arch/x86/include/asm/segment.h
--- linux-libre-5.4-gnu/arch/x86/include/asm/segment.h	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/x86/include/asm/segment.h	2019-11-29 04:10:32.000000000 -0500
@@ -31,6 +31,18 @@
  */
 #define SEGMENT_RPL_MASK	0x3
 
+/*
+ * When running on Xen PV, the actual privilege level of the kernel is 1,
+ * not 0. Testing the Requested Privilege Level in a segment selector to
+ * determine whether the context is user mode or kernel mode with
+ * SEGMENT_RPL_MASK is wrong because the PV kernel's privilege level
+ * matches the 0x3 mask.
+ *
+ * Testing with USER_SEGMENT_RPL_MASK is valid for both native and Xen PV
+ * kernels because privilege level 2 is never used.
+ */
+#define USER_SEGMENT_RPL_MASK	0x2
+
 /* User mode is privilege level 3: */
 #define USER_RPL		0x3
 
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/x86/kernel/cpu/bugs.c linux-libre-5.4.1-gnu/arch/x86/kernel/cpu/bugs.c
--- linux-libre-5.4-gnu/arch/x86/kernel/cpu/bugs.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/x86/kernel/cpu/bugs.c	2019-11-29 04:10:32.000000000 -0500
@@ -39,6 +39,7 @@ static void __init spectre_v2_select_mit
 static void __init ssb_select_mitigation(void);
 static void __init l1tf_select_mitigation(void);
 static void __init mds_select_mitigation(void);
+static void __init mds_print_mitigation(void);
 static void __init taa_select_mitigation(void);
 
 /* The base value of the SPEC_CTRL MSR that always has to be preserved. */
@@ -108,6 +109,12 @@ void __init check_bugs(void)
 	mds_select_mitigation();
 	taa_select_mitigation();
 
+	/*
+	 * As MDS and TAA mitigations are inter-related, print MDS
+	 * mitigation until after TAA mitigation selection is done.
+	 */
+	mds_print_mitigation();
+
 	arch_smt_update();
 
 #ifdef CONFIG_X86_32
@@ -245,6 +252,12 @@ static void __init mds_select_mitigation
 		    (mds_nosmt || cpu_mitigations_auto_nosmt()))
 			cpu_smt_disable(false);
 	}
+}
+
+static void __init mds_print_mitigation(void)
+{
+	if (!boot_cpu_has_bug(X86_BUG_MDS) || cpu_mitigations_off())
+		return;
 
 	pr_info("%s\n", mds_strings[mds_mitigation]);
 }
@@ -304,8 +317,12 @@ static void __init taa_select_mitigation
 		return;
 	}
 
-	/* TAA mitigation is turned off on the cmdline (tsx_async_abort=off) */
-	if (taa_mitigation == TAA_MITIGATION_OFF)
+	/*
+	 * TAA mitigation via VERW is turned off if both
+	 * tsx_async_abort=off and mds=off are specified.
+	 */
+	if (taa_mitigation == TAA_MITIGATION_OFF &&
+	    mds_mitigation == MDS_MITIGATION_OFF)
 		goto out;
 
 	if (boot_cpu_has(X86_FEATURE_MD_CLEAR))
@@ -339,6 +356,15 @@ static void __init taa_select_mitigation
 	if (taa_nosmt || cpu_mitigations_auto_nosmt())
 		cpu_smt_disable(false);
 
+	/*
+	 * Update MDS mitigation, if necessary, as the mds_user_clear is
+	 * now enabled for TAA mitigation.
+	 */
+	if (mds_mitigation == MDS_MITIGATION_OFF &&
+	    boot_cpu_has_bug(X86_BUG_MDS)) {
+		mds_mitigation = MDS_MITIGATION_FULL;
+		mds_select_mitigation();
+	}
 out:
 	pr_info("%s\n", taa_strings[taa_mitigation]);
 }
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/x86/kernel/doublefault.c linux-libre-5.4.1-gnu/arch/x86/kernel/doublefault.c
--- linux-libre-5.4-gnu/arch/x86/kernel/doublefault.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/x86/kernel/doublefault.c	2019-11-29 04:10:32.000000000 -0500
@@ -65,6 +65,9 @@ struct x86_hw_tss doublefault_tss __cach
 	.ss		= __KERNEL_DS,
 	.ds		= __USER_DS,
 	.fs		= __KERNEL_PERCPU,
+#ifndef CONFIG_X86_32_LAZY_GS
+	.gs		= __KERNEL_STACK_CANARY,
+#endif
 
 	.__cr3		= __pa_nodebug(swapper_pg_dir),
 };
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/x86/kernel/head_32.S linux-libre-5.4.1-gnu/arch/x86/kernel/head_32.S
--- linux-libre-5.4-gnu/arch/x86/kernel/head_32.S	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/x86/kernel/head_32.S	2019-11-29 04:10:32.000000000 -0500
@@ -571,6 +571,16 @@ ENTRY(initial_page_table)
 #  error "Kernel PMDs should be 1, 2 or 3"
 # endif
 	.align PAGE_SIZE		/* needs to be page-sized too */
+
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+	/*
+	 * PTI needs another page so sync_initial_pagetable() works correctly
+	 * and does not scribble over the data which is placed behind the
+	 * actual initial_page_table. See clone_pgd_range().
+	 */
+	.fill 1024, 4, 0
+#endif
+
 #endif
 
 .data
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/x86/mm/cpu_entry_area.c linux-libre-5.4.1-gnu/arch/x86/mm/cpu_entry_area.c
--- linux-libre-5.4-gnu/arch/x86/mm/cpu_entry_area.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/x86/mm/cpu_entry_area.c	2019-11-29 04:10:32.000000000 -0500
@@ -178,7 +178,9 @@ static __init void setup_cpu_entry_area_
 #ifdef CONFIG_X86_32
 	unsigned long start, end;
 
-	BUILD_BUG_ON(CPU_ENTRY_AREA_PAGES * PAGE_SIZE < CPU_ENTRY_AREA_MAP_SIZE);
+	/* The +1 is for the readonly IDT: */
+	BUILD_BUG_ON((CPU_ENTRY_AREA_PAGES+1)*PAGE_SIZE != CPU_ENTRY_AREA_MAP_SIZE);
+	BUILD_BUG_ON(CPU_ENTRY_AREA_TOTAL_SIZE != CPU_ENTRY_AREA_MAP_SIZE);
 	BUG_ON(CPU_ENTRY_AREA_BASE & ~PMD_MASK);
 
 	start = CPU_ENTRY_AREA_BASE;
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/x86/tools/gen-insn-attr-x86.awk linux-libre-5.4.1-gnu/arch/x86/tools/gen-insn-attr-x86.awk
--- linux-libre-5.4-gnu/arch/x86/tools/gen-insn-attr-x86.awk	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/x86/tools/gen-insn-attr-x86.awk	2019-11-29 04:10:32.000000000 -0500
@@ -69,7 +69,7 @@ BEGIN {
 
 	lprefix1_expr = "\\((66|!F3)\\)"
 	lprefix2_expr = "\\(F3\\)"
-	lprefix3_expr = "\\((F2|!F3|66\\&F2)\\)"
+	lprefix3_expr = "\\((F2|!F3|66&F2)\\)"
 	lprefix_expr = "\\((66|F2|F3)\\)"
 	max_lprefix = 4
 
@@ -257,7 +257,7 @@ function convert_operands(count,opnd,
 	return add_flags(imm, mod)
 }
 
-/^[0-9a-f]+\:/ {
+/^[0-9a-f]+:/ {
 	if (NR == 1)
 		next
 	# get index
diff -druNp --no-dereference linux-libre-5.4-gnu/arch/x86/xen/xen-asm_32.S linux-libre-5.4.1-gnu/arch/x86/xen/xen-asm_32.S
--- linux-libre-5.4-gnu/arch/x86/xen/xen-asm_32.S	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/arch/x86/xen/xen-asm_32.S	2019-11-29 04:10:32.000000000 -0500
@@ -126,10 +126,9 @@ hyper_iret:
 	.globl xen_iret_start_crit, xen_iret_end_crit
 
 /*
- * This is called by xen_hypervisor_callback in entry.S when it sees
+ * This is called by xen_hypervisor_callback in entry_32.S when it sees
  * that the EIP at the time of interrupt was between
- * xen_iret_start_crit and xen_iret_end_crit.  We're passed the EIP in
- * %eax so we can do a more refined determination of what to do.
+ * xen_iret_start_crit and xen_iret_end_crit.
  *
  * The stack format at this point is:
  *	----------------
@@ -138,70 +137,46 @@ hyper_iret:
  *	 eflags		}  outer exception info
  *	 cs		}
  *	 eip		}
- *	---------------- <- edi (copy dest)
- *	 eax		:  outer eax if it hasn't been restored
  *	----------------
- *	 eflags		}  nested exception info
- *	 cs		}   (no ss/esp because we're nested
- *	 eip		}    from the same ring)
- *	 orig_eax	}<- esi (copy src)
- *	 - - - - - - - -
- *	 fs		}
- *	 es		}
- *	 ds		}  SAVE_ALL state
- *	 eax		}
- *	  :		:
- *	 ebx		}<- esp
+ *	 eax		:  outer eax if it hasn't been restored
  *	----------------
+ *	 eflags		}
+ *	 cs		}  nested exception info
+ *	 eip		}
+ *	 return address	: (into xen_hypervisor_callback)
  *
- * In order to deliver the nested exception properly, we need to shift
- * everything from the return addr up to the error code so it sits
- * just under the outer exception info.  This means that when we
- * handle the exception, we do it in the context of the outer
- * exception rather than starting a new one.
+ * In order to deliver the nested exception properly, we need to discard the
+ * nested exception frame such that when we handle the exception, we do it
+ * in the context of the outer exception rather than starting a new one.
  *
- * The only caveat is that if the outer eax hasn't been restored yet
- * (ie, it's still on stack), we need to insert its value into the
- * SAVE_ALL state before going on, since it's usermode state which we
- * eventually need to restore.
+ * The only caveat is that if the outer eax hasn't been restored yet (i.e.
+ * it's still on stack), we need to restore its value here.
  */
 ENTRY(xen_iret_crit_fixup)
 	/*
 	 * Paranoia: Make sure we're really coming from kernel space.
 	 * One could imagine a case where userspace jumps into the
 	 * critical range address, but just before the CPU delivers a
-	 * GP, it decides to deliver an interrupt instead.  Unlikely?
-	 * Definitely.  Easy to avoid?  Yes.  The Intel documents
-	 * explicitly say that the reported EIP for a bad jump is the
-	 * jump instruction itself, not the destination, but some
-	 * virtual environments get this wrong.
+	 * PF, it decides to deliver an interrupt instead.  Unlikely?
+	 * Definitely.  Easy to avoid?  Yes.
 	 */
-	movl PT_CS(%esp), %ecx
-	andl $SEGMENT_RPL_MASK, %ecx
-	cmpl $USER_RPL, %ecx
-	je 2f
-
-	lea PT_ORIG_EAX(%esp), %esi
-	lea PT_EFLAGS(%esp), %edi
+	testb $2, 2*4(%esp)		/* nested CS */
+	jnz 2f
 
 	/*
 	 * If eip is before iret_restore_end then stack
 	 * hasn't been restored yet.
 	 */
-	cmp $iret_restore_end, %eax
+	cmpl $iret_restore_end, 1*4(%esp)
 	jae 1f
 
-	movl 0+4(%edi), %eax		/* copy EAX (just above top of frame) */
-	movl %eax, PT_EAX(%esp)
-
-	lea ESP_OFFSET(%edi), %edi	/* move dest up over saved regs */
-
-	/* set up the copy */
-1:	std
-	mov $PT_EIP / 4, %ecx		/* saved regs up to orig_eax */
-	rep movsl
-	cld
+	movl 4*4(%esp), %eax		/* load outer EAX */
+	ret $4*4			/* discard nested EIP, CS, and EFLAGS as
+					 * well as the just restored EAX */
 
-	lea 4(%edi), %esp		/* point esp to new frame */
-2:	jmp xen_do_upcall
+1:
+	ret $3*4			/* discard nested EIP, CS, and EFLAGS */
 
+2:
+	ret
+END(xen_iret_crit_fixup)
diff -druNp --no-dereference linux-libre-5.4-gnu/Documentation/admin-guide/hw-vuln/mds.rst linux-libre-5.4.1-gnu/Documentation/admin-guide/hw-vuln/mds.rst
--- linux-libre-5.4-gnu/Documentation/admin-guide/hw-vuln/mds.rst	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/Documentation/admin-guide/hw-vuln/mds.rst	2019-11-29 04:10:32.000000000 -0500
@@ -265,8 +265,11 @@ time with the option "mds=". The valid a
 
   ============  =============================================================
 
-Not specifying this option is equivalent to "mds=full".
-
+Not specifying this option is equivalent to "mds=full". For processors
+that are affected by both TAA (TSX Asynchronous Abort) and MDS,
+specifying just "mds=off" without an accompanying "tsx_async_abort=off"
+will have no effect as the same mitigation is used for both
+vulnerabilities.
 
 Mitigation selection guide
 --------------------------
diff -druNp --no-dereference linux-libre-5.4-gnu/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst linux-libre-5.4.1-gnu/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
--- linux-libre-5.4-gnu/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst	2019-11-29 04:10:32.000000000 -0500
@@ -174,7 +174,10 @@ the option "tsx_async_abort=". The valid
                 CPU is not vulnerable to cross-thread TAA attacks.
   ============  =============================================================
 
-Not specifying this option is equivalent to "tsx_async_abort=full".
+Not specifying this option is equivalent to "tsx_async_abort=full". For
+processors that are affected by both TAA and MDS, specifying just
+"tsx_async_abort=off" without an accompanying "mds=off" will have no
+effect as the same mitigation is used for both vulnerabilities.
 
 The kernel command line also allows to control the TSX feature using the
 parameter "tsx=" on CPUs which support TSX control. MSR_IA32_TSX_CTRL is used
diff -druNp --no-dereference linux-libre-5.4-gnu/Documentation/admin-guide/kernel-parameters.txt linux-libre-5.4.1-gnu/Documentation/admin-guide/kernel-parameters.txt
--- linux-libre-5.4-gnu/Documentation/admin-guide/kernel-parameters.txt	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/Documentation/admin-guide/kernel-parameters.txt	2019-11-29 04:10:32.000000000 -0500
@@ -2473,6 +2473,12 @@
 				     SMT on vulnerable CPUs
 			off        - Unconditionally disable MDS mitigation
 
+			On TAA-affected machines, mds=off can be prevented by
+			an active TAA mitigation as both vulnerabilities are
+			mitigated with the same mechanism so in order to disable
+			this mitigation, you need to specify tsx_async_abort=off
+			too.
+
 			Not specifying this option is equivalent to
 			mds=full.
 
@@ -4931,6 +4937,11 @@
 				     vulnerable to cross-thread TAA attacks.
 			off        - Unconditionally disable TAA mitigation
 
+			On MDS-affected machines, tsx_async_abort=off can be
+			prevented by an active MDS mitigation as both vulnerabilities
+			are mitigated with the same mechanism so in order to disable
+			this mitigation, you need to specify mds=off too.
+
 			Not specifying this option is equivalent to
 			tsx_async_abort=full.  On CPUs which are MDS affected
 			and deploy MDS mitigation, TAA mitigation is not
diff -druNp --no-dereference linux-libre-5.4-gnu/Documentation/devicetree/bindings/net/wireless/qcom,ath10k.txt linux-libre-5.4.1-gnu/Documentation/devicetree/bindings/net/wireless/qcom,ath10k.txt
--- linux-libre-5.4-gnu/Documentation/devicetree/bindings/net/wireless/qcom,ath10k.txt	2019-11-24 21:13:00.000000000 -0500
+++ linux-libre-5.4.1-gnu/Documentation/devicetree/bindings/net/wireless/qcom,ath10k.txt	2019-11-29 06:49:34.000000000 -0500
@@ -81,6 +81,12 @@ Optional properties:
 	Definition: Name of external front end module used. Some valid FEM names
 		    for example: "microsemi-lx5586", "sky85703-11"
 		    and "sky85803" etc.
+- qcom,snoc-host-cap-8bit-quirk:
+	Usage: Optional
+	Value type: <empty>
+	Definition: Quirk specifying that the firmware expects the 8bit version
+		    of the host capability QMI request
+
 
 Example (to supply PCI based wifi block details):
 
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/block/nbd.c linux-libre-5.4.1-gnu/drivers/block/nbd.c
--- linux-libre-5.4-gnu/drivers/block/nbd.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/block/nbd.c	2019-11-29 04:10:32.000000000 -0500
@@ -1032,14 +1032,15 @@ static int nbd_add_socket(struct nbd_dev
 		sockfd_put(sock);
 		return -ENOMEM;
 	}
+
+	config->socks = socks;
+
 	nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL);
 	if (!nsock) {
 		sockfd_put(sock);
 		return -ENOMEM;
 	}
 
-	config->socks = socks;
-
 	nsock->fallback_index = -1;
 	nsock->dead = false;
 	mutex_init(&nsock->tx_lock);
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/bluetooth/hci_bcsp.c linux-libre-5.4.1-gnu/drivers/bluetooth/hci_bcsp.c
--- linux-libre-5.4-gnu/drivers/bluetooth/hci_bcsp.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/bluetooth/hci_bcsp.c	2019-11-29 04:10:32.000000000 -0500
@@ -591,6 +591,7 @@ static int bcsp_recv(struct hci_uart *hu
 			if (*ptr == 0xc0) {
 				BT_ERR("Short BCSP packet");
 				kfree_skb(bcsp->rx_skb);
+				bcsp->rx_skb = NULL;
 				bcsp->rx_state = BCSP_W4_PKT_START;
 				bcsp->rx_count = 0;
 			} else
@@ -606,6 +607,7 @@ static int bcsp_recv(struct hci_uart *hu
 			    bcsp->rx_skb->data[2])) != bcsp->rx_skb->data[3]) {
 				BT_ERR("Error in BCSP hdr checksum");
 				kfree_skb(bcsp->rx_skb);
+				bcsp->rx_skb = NULL;
 				bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 				bcsp->rx_count = 0;
 				continue;
@@ -630,6 +632,7 @@ static int bcsp_recv(struct hci_uart *hu
 				       bscp_get_crc(bcsp));
 
 				kfree_skb(bcsp->rx_skb);
+				bcsp->rx_skb = NULL;
 				bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 				bcsp->rx_count = 0;
 				continue;
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/bluetooth/hci_ll.c linux-libre-5.4.1-gnu/drivers/bluetooth/hci_ll.c
--- linux-libre-5.4-gnu/drivers/bluetooth/hci_ll.c	2019-11-24 21:17:16.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/bluetooth/hci_ll.c	2019-11-29 06:53:23.000000000 -0500
@@ -621,13 +621,6 @@ static int ll_setup(struct hci_uart *hu)
 
 	serdev_device_set_flow_control(serdev, true);
 
-	if (hu->oper_speed)
-		speed = hu->oper_speed;
-	else if (hu->proto->oper_speed)
-		speed = hu->proto->oper_speed;
-	else
-		speed = 0;
-
 	do {
 		/* Reset the Bluetooth device */
 		gpiod_set_value_cansleep(lldev->enable_gpio, 0);
@@ -639,20 +632,6 @@ static int ll_setup(struct hci_uart *hu)
 			return err;
 		}
 
-		if (speed) {
-			__le32 speed_le = cpu_to_le32(speed);
-			struct sk_buff *skb;
-
-			skb = __hci_cmd_sync(hu->hdev,
-					     HCI_VS_UPDATE_UART_HCI_BAUDRATE,
-					     sizeof(speed_le), &speed_le,
-					     HCI_INIT_TIMEOUT);
-			if (!IS_ERR(skb)) {
-				kfree_skb(skb);
-				serdev_device_set_baudrate(serdev, speed);
-			}
-		}
-
 		err = download_firmware(lldev);
 		if (!err)
 			break;
@@ -677,7 +656,25 @@ static int ll_setup(struct hci_uart *hu)
 	}
 
 	/* Operational speed if any */
+	if (hu->oper_speed)
+		speed = hu->oper_speed;
+	else if (hu->proto->oper_speed)
+		speed = hu->proto->oper_speed;
+	else
+		speed = 0;
 
+	if (speed) {
+		__le32 speed_le = cpu_to_le32(speed);
+		struct sk_buff *skb;
+
+		skb = __hci_cmd_sync(hu->hdev, HCI_VS_UPDATE_UART_HCI_BAUDRATE,
+				     sizeof(speed_le), &speed_le,
+				     HCI_INIT_TIMEOUT);
+		if (!IS_ERR(skb)) {
+			kfree_skb(skb);
+			serdev_device_set_baudrate(serdev, speed);
+		}
+	}
 
 	return 0;
 }
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/cpufreq/cpufreq.c linux-libre-5.4.1-gnu/drivers/cpufreq/cpufreq.c
--- linux-libre-5.4-gnu/drivers/cpufreq/cpufreq.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/cpufreq/cpufreq.c	2019-11-29 04:10:32.000000000 -0500
@@ -933,6 +933,9 @@ static ssize_t show(struct kobject *kobj
 	struct freq_attr *fattr = to_attr(attr);
 	ssize_t ret;
 
+	if (!fattr->show)
+		return -EIO;
+
 	down_read(&policy->rwsem);
 	ret = fattr->show(policy, buf);
 	up_read(&policy->rwsem);
@@ -947,6 +950,9 @@ static ssize_t store(struct kobject *kob
 	struct freq_attr *fattr = to_attr(attr);
 	ssize_t ret = -EINVAL;
 
+	if (!fattr->store)
+		return -EIO;
+
 	/*
 	 * cpus_read_trylock() is used here to work around a circular lock
 	 * dependency problem with respect to the cpufreq_register_driver().
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/md/dm-crypt.c linux-libre-5.4.1-gnu/drivers/md/dm-crypt.c
--- linux-libre-5.4-gnu/drivers/md/dm-crypt.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/md/dm-crypt.c	2019-11-29 04:10:32.000000000 -0500
@@ -2700,21 +2700,18 @@ static int crypt_ctr(struct dm_target *t
 	}
 
 	ret = -ENOMEM;
-	cc->io_queue = alloc_workqueue("kcryptd_io/%s",
-				       WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
-				       1, devname);
+	cc->io_queue = alloc_workqueue("kcryptd_io/%s", WQ_MEM_RECLAIM, 1, devname);
 	if (!cc->io_queue) {
 		ti->error = "Couldn't create kcryptd io queue";
 		goto bad;
 	}
 
 	if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
-		cc->crypt_queue = alloc_workqueue("kcryptd/%s",
-						  WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
+		cc->crypt_queue = alloc_workqueue("kcryptd/%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
 						  1, devname);
 	else
 		cc->crypt_queue = alloc_workqueue("kcryptd/%s",
-						  WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
+						  WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
 						  num_online_cpus(), devname);
 	if (!cc->crypt_queue) {
 		ti->error = "Couldn't create kcryptd queue";
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/md/raid10.c linux-libre-5.4.1-gnu/drivers/md/raid10.c
--- linux-libre-5.4-gnu/drivers/md/raid10.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/md/raid10.c	2019-11-29 04:10:32.000000000 -0500
@@ -191,7 +191,7 @@ static void * r10buf_pool_alloc(gfp_t gf
 
 out_free_pages:
 	while (--j >= 0)
-		resync_free_pages(&rps[j * 2]);
+		resync_free_pages(&rps[j]);
 
 	j = 0;
 out_free_bio:
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/media/platform/vivid/vivid-kthread-cap.c linux-libre-5.4.1-gnu/drivers/media/platform/vivid/vivid-kthread-cap.c
--- linux-libre-5.4-gnu/drivers/media/platform/vivid/vivid-kthread-cap.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/media/platform/vivid/vivid-kthread-cap.c	2019-11-29 04:10:32.000000000 -0500
@@ -796,7 +796,11 @@ static int vivid_thread_vid_cap(void *da
 		if (kthread_should_stop())
 			break;
 
-		mutex_lock(&dev->mutex);
+		if (!mutex_trylock(&dev->mutex)) {
+			schedule_timeout_uninterruptible(1);
+			continue;
+		}
+
 		cur_jiffies = jiffies;
 		if (dev->cap_seq_resync) {
 			dev->jiffies_vid_cap = cur_jiffies;
@@ -956,8 +960,6 @@ void vivid_stop_generating_vid_cap(struc
 
 	/* shutdown control thread */
 	vivid_grab_controls(dev, false);
-	mutex_unlock(&dev->mutex);
 	kthread_stop(dev->kthread_vid_cap);
 	dev->kthread_vid_cap = NULL;
-	mutex_lock(&dev->mutex);
 }
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/media/platform/vivid/vivid-kthread-out.c linux-libre-5.4.1-gnu/drivers/media/platform/vivid/vivid-kthread-out.c
--- linux-libre-5.4-gnu/drivers/media/platform/vivid/vivid-kthread-out.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/media/platform/vivid/vivid-kthread-out.c	2019-11-29 04:10:32.000000000 -0500
@@ -143,7 +143,11 @@ static int vivid_thread_vid_out(void *da
 		if (kthread_should_stop())
 			break;
 
-		mutex_lock(&dev->mutex);
+		if (!mutex_trylock(&dev->mutex)) {
+			schedule_timeout_uninterruptible(1);
+			continue;
+		}
+
 		cur_jiffies = jiffies;
 		if (dev->out_seq_resync) {
 			dev->jiffies_vid_out = cur_jiffies;
@@ -301,8 +305,6 @@ void vivid_stop_generating_vid_out(struc
 
 	/* shutdown control thread */
 	vivid_grab_controls(dev, false);
-	mutex_unlock(&dev->mutex);
 	kthread_stop(dev->kthread_vid_out);
 	dev->kthread_vid_out = NULL;
-	mutex_lock(&dev->mutex);
 }
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/media/platform/vivid/vivid-sdr-cap.c linux-libre-5.4.1-gnu/drivers/media/platform/vivid/vivid-sdr-cap.c
--- linux-libre-5.4-gnu/drivers/media/platform/vivid/vivid-sdr-cap.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/media/platform/vivid/vivid-sdr-cap.c	2019-11-29 04:10:32.000000000 -0500
@@ -141,7 +141,11 @@ static int vivid_thread_sdr_cap(void *da
 		if (kthread_should_stop())
 			break;
 
-		mutex_lock(&dev->mutex);
+		if (!mutex_trylock(&dev->mutex)) {
+			schedule_timeout_uninterruptible(1);
+			continue;
+		}
+
 		cur_jiffies = jiffies;
 		if (dev->sdr_cap_seq_resync) {
 			dev->jiffies_sdr_cap = cur_jiffies;
@@ -303,10 +307,8 @@ static void sdr_cap_stop_streaming(struc
 	}
 
 	/* shutdown control thread */
-	mutex_unlock(&dev->mutex);
 	kthread_stop(dev->kthread_sdr_cap);
 	dev->kthread_sdr_cap = NULL;
-	mutex_lock(&dev->mutex);
 }
 
 static void sdr_cap_buf_request_complete(struct vb2_buffer *vb)
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/media/platform/vivid/vivid-vid-cap.c linux-libre-5.4.1-gnu/drivers/media/platform/vivid/vivid-vid-cap.c
--- linux-libre-5.4-gnu/drivers/media/platform/vivid/vivid-vid-cap.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/media/platform/vivid/vivid-vid-cap.c	2019-11-29 04:10:32.000000000 -0500
@@ -223,9 +223,6 @@ static int vid_cap_start_streaming(struc
 	if (vb2_is_streaming(&dev->vb_vid_out_q))
 		dev->can_loop_video = vivid_vid_can_loop(dev);
 
-	if (dev->kthread_vid_cap)
-		return 0;
-
 	dev->vid_cap_seq_count = 0;
 	dprintk(dev, 1, "%s\n", __func__);
 	for (i = 0; i < VIDEO_MAX_FRAME; i++)
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/media/platform/vivid/vivid-vid-out.c linux-libre-5.4.1-gnu/drivers/media/platform/vivid/vivid-vid-out.c
--- linux-libre-5.4-gnu/drivers/media/platform/vivid/vivid-vid-out.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/media/platform/vivid/vivid-vid-out.c	2019-11-29 04:10:32.000000000 -0500
@@ -161,9 +161,6 @@ static int vid_out_start_streaming(struc
 	if (vb2_is_streaming(&dev->vb_vid_cap_q))
 		dev->can_loop_video = vivid_vid_can_loop(dev);
 
-	if (dev->kthread_vid_out)
-		return 0;
-
 	dev->vid_out_seq_count = 0;
 	dprintk(dev, 1, "%s\n", __func__);
 	if (dev->start_streaming_error) {
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/media/rc/imon.c linux-libre-5.4.1-gnu/drivers/media/rc/imon.c
--- linux-libre-5.4-gnu/drivers/media/rc/imon.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/media/rc/imon.c	2019-11-29 04:10:32.000000000 -0500
@@ -1598,8 +1598,7 @@ static void imon_incoming_packet(struct
 	spin_unlock_irqrestore(&ictx->kc_lock, flags);
 
 	/* send touchscreen events through input subsystem if touchpad data */
-	if (ictx->display_type == IMON_DISPLAY_TYPE_VGA && len == 8 &&
-	    buf[7] == 0x86) {
+	if (ictx->touch && len == 8 && buf[7] == 0x86) {
 		imon_touch_event(ictx, buf);
 		return;
 
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/media/rc/mceusb.c linux-libre-5.4.1-gnu/drivers/media/rc/mceusb.c
--- linux-libre-5.4-gnu/drivers/media/rc/mceusb.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/media/rc/mceusb.c	2019-11-29 04:10:32.000000000 -0500
@@ -564,7 +564,7 @@ static int mceusb_cmd_datasize(u8 cmd, u
 			datasize = 4;
 			break;
 		case MCE_CMD_G_REVISION:
-			datasize = 2;
+			datasize = 4;
 			break;
 		case MCE_RSP_EQWAKESUPPORT:
 		case MCE_RSP_GETWAKESOURCE:
@@ -600,14 +600,9 @@ static void mceusb_dev_printdata(struct
 	char *inout;
 	u8 cmd, subcmd, *data;
 	struct device *dev = ir->dev;
-	int start, skip = 0;
 	u32 carrier, period;
 
-	/* skip meaningless 0xb1 0x60 header bytes on orig receiver */
-	if (ir->flags.microsoft_gen1 && !out && !offset)
-		skip = 2;
-
-	if (len <= skip)
+	if (offset < 0 || offset >= buf_len)
 		return;
 
 	dev_dbg(dev, "%cx data[%d]: %*ph (len=%d sz=%d)",
@@ -616,11 +611,32 @@ static void mceusb_dev_printdata(struct
 
 	inout = out ? "Request" : "Got";
 
-	start  = offset + skip;
-	cmd    = buf[start] & 0xff;
-	subcmd = buf[start + 1] & 0xff;
-	data = buf + start + 2;
+	cmd    = buf[offset];
+	subcmd = (offset + 1 < buf_len) ? buf[offset + 1] : 0;
+	data   = &buf[offset] + 2;
+
+	/* Trace meaningless 0xb1 0x60 header bytes on original receiver */
+	if (ir->flags.microsoft_gen1 && !out && !offset) {
+		dev_dbg(dev, "MCE gen 1 header");
+		return;
+	}
+
+	/* Trace IR data header or trailer */
+	if (cmd != MCE_CMD_PORT_IR &&
+	    (cmd & MCE_PORT_MASK) == MCE_COMMAND_IRDATA) {
+		if (cmd == MCE_IRDATA_TRAILER)
+			dev_dbg(dev, "End of raw IR data");
+		else
+			dev_dbg(dev, "Raw IR data, %d pulse/space samples",
+				cmd & MCE_PACKET_LENGTH_MASK);
+		return;
+	}
 
+	/* Unexpected end of buffer? */
+	if (offset + len > buf_len)
+		return;
+
+	/* Decode MCE command/response */
 	switch (cmd) {
 	case MCE_CMD_NULL:
 		if (subcmd == MCE_CMD_NULL)
@@ -644,7 +660,7 @@ static void mceusb_dev_printdata(struct
 				dev_dbg(dev, "Get hw/sw rev?");
 			else
 				dev_dbg(dev, "hw/sw rev %*ph",
-					4, &buf[start + 2]);
+					4, &buf[offset + 2]);
 			break;
 		case MCE_CMD_RESUME:
 			dev_dbg(dev, "Device resume requested");
@@ -746,13 +762,6 @@ static void mceusb_dev_printdata(struct
 	default:
 		break;
 	}
-
-	if (cmd == MCE_IRDATA_TRAILER)
-		dev_dbg(dev, "End of raw IR data");
-	else if ((cmd != MCE_CMD_PORT_IR) &&
-		 ((cmd & MCE_PORT_MASK) == MCE_COMMAND_IRDATA))
-		dev_dbg(dev, "Raw IR data, %d pulse/space samples",
-			cmd & MCE_PACKET_LENGTH_MASK);
 #endif
 }
 
@@ -1136,32 +1145,62 @@ static int mceusb_set_rx_carrier_report(
 }
 
 /*
+ * Handle PORT_SYS/IR command response received from the MCE device.
+ *
+ * Assumes single response with all its data (not truncated)
+ * in buf_in[]. The response itself determines its total length
+ * (mceusb_cmd_datasize() + 2) and hence the minimum size of buf_in[].
+ *
  * We don't do anything but print debug spew for many of the command bits
  * we receive from the hardware, but some of them are useful information
  * we want to store so that we can use them.
  */
-static void mceusb_handle_command(struct mceusb_dev *ir, int index)
+static void mceusb_handle_command(struct mceusb_dev *ir, u8 *buf_in)
 {
+	u8 cmd = buf_in[0];
+	u8 subcmd = buf_in[1];
+	u8 *hi = &buf_in[2];		/* read only when required */
+	u8 *lo = &buf_in[3];		/* read only when required */
 	struct ir_raw_event rawir = {};
-	u8 hi = ir->buf_in[index + 1] & 0xff;
-	u8 lo = ir->buf_in[index + 2] & 0xff;
 	u32 carrier_cycles;
 	u32 cycles_fix;
 
-	switch (ir->buf_in[index]) {
-	/* the one and only 5-byte return value command */
-	case MCE_RSP_GETPORTSTATUS:
-		if ((ir->buf_in[index + 4] & 0xff) == 0x00)
-			ir->txports_cabled |= 1 << hi;
-		break;
+	if (cmd == MCE_CMD_PORT_SYS) {
+		switch (subcmd) {
+		/* the one and only 5-byte return value command */
+		case MCE_RSP_GETPORTSTATUS:
+			if (buf_in[5] == 0)
+				ir->txports_cabled |= 1 << *hi;
+			break;
+
+		/* 1-byte return value commands */
+		case MCE_RSP_EQEMVER:
+			ir->emver = *hi;
+			break;
+
+		/* No return value commands */
+		case MCE_RSP_CMD_ILLEGAL:
+			ir->need_reset = true;
+			break;
 
+		default:
+			break;
+		}
+
+		return;
+	}
+
+	if (cmd != MCE_CMD_PORT_IR)
+		return;
+
+	switch (subcmd) {
 	/* 2-byte return value commands */
 	case MCE_RSP_EQIRTIMEOUT:
-		ir->rc->timeout = US_TO_NS((hi << 8 | lo) * MCE_TIME_UNIT);
+		ir->rc->timeout = US_TO_NS((*hi << 8 | *lo) * MCE_TIME_UNIT);
 		break;
 	case MCE_RSP_EQIRNUMPORTS:
-		ir->num_txports = hi;
-		ir->num_rxports = lo;
+		ir->num_txports = *hi;
+		ir->num_rxports = *lo;
 		break;
 	case MCE_RSP_EQIRRXCFCNT:
 		/*
@@ -1174,7 +1213,7 @@ static void mceusb_handle_command(struct
 		 */
 		if (ir->carrier_report_enabled && ir->learning_active &&
 		    ir->pulse_tunit > 0) {
-			carrier_cycles = (hi << 8 | lo);
+			carrier_cycles = (*hi << 8 | *lo);
 			/*
 			 * Adjust carrier cycle count by adding
 			 * 1 missed count per pulse "on"
@@ -1192,24 +1231,24 @@ static void mceusb_handle_command(struct
 		break;
 
 	/* 1-byte return value commands */
-	case MCE_RSP_EQEMVER:
-		ir->emver = hi;
-		break;
 	case MCE_RSP_EQIRTXPORTS:
-		ir->tx_mask = hi;
+		ir->tx_mask = *hi;
 		break;
 	case MCE_RSP_EQIRRXPORTEN:
-		ir->learning_active = ((hi & 0x02) == 0x02);
-		if (ir->rxports_active != hi) {
+		ir->learning_active = ((*hi & 0x02) == 0x02);
+		if (ir->rxports_active != *hi) {
 			dev_info(ir->dev, "%s-range (0x%x) receiver active",
-				 ir->learning_active ? "short" : "long", hi);
-			ir->rxports_active = hi;
+				 ir->learning_active ? "short" : "long", *hi);
+			ir->rxports_active = *hi;
 		}
 		break;
+
+	/* No return value commands */
 	case MCE_RSP_CMD_ILLEGAL:
 	case MCE_RSP_TX_TIMEOUT:
 		ir->need_reset = true;
 		break;
+
 	default:
 		break;
 	}
@@ -1235,7 +1274,8 @@ static void mceusb_process_ir_data(struc
 			ir->rem = mceusb_cmd_datasize(ir->cmd, ir->buf_in[i]);
 			mceusb_dev_printdata(ir, ir->buf_in, buf_len, i - 1,
 					     ir->rem + 2, false);
-			mceusb_handle_command(ir, i);
+			if (i + ir->rem < buf_len)
+				mceusb_handle_command(ir, &ir->buf_in[i - 1]);
 			ir->parser_state = CMD_DATA;
 			break;
 		case PARSE_IRDATA:
@@ -1264,15 +1304,22 @@ static void mceusb_process_ir_data(struc
 			ir->rem--;
 			break;
 		case CMD_HEADER:
-			/* decode mce packets of the form (84),AA,BB,CC,DD */
-			/* IR data packets can span USB messages - rem */
 			ir->cmd = ir->buf_in[i];
 			if ((ir->cmd == MCE_CMD_PORT_IR) ||
 			    ((ir->cmd & MCE_PORT_MASK) !=
 			     MCE_COMMAND_IRDATA)) {
+				/*
+				 * got PORT_SYS, PORT_IR, or unknown
+				 * command response prefix
+				 */
 				ir->parser_state = SUBCMD;
 				continue;
 			}
+			/*
+			 * got IR data prefix (0x80 + num_bytes)
+			 * decode MCE packets of the form {0x83, AA, BB, CC}
+			 * IR data packets can span USB messages
+			 */
 			ir->rem = (ir->cmd & MCE_PACKET_LENGTH_MASK);
 			mceusb_dev_printdata(ir, ir->buf_in, buf_len,
 					     i, ir->rem + 1, false);
@@ -1296,6 +1343,14 @@ static void mceusb_process_ir_data(struc
 		if (ir->parser_state != CMD_HEADER && !ir->rem)
 			ir->parser_state = CMD_HEADER;
 	}
+
+	/*
+	 * Accept IR data spanning multiple rx buffers.
+	 * Reject MCE command response spanning multiple rx buffers.
+	 */
+	if (ir->parser_state != PARSE_IRDATA || !ir->rem)
+		ir->parser_state = CMD_HEADER;
+
 	if (event) {
 		dev_dbg(ir->dev, "processed IR data");
 		ir_raw_event_handle(ir->rc);
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/media/usb/b2c2/flexcop-usb.c linux-libre-5.4.1-gnu/drivers/media/usb/b2c2/flexcop-usb.c
--- linux-libre-5.4-gnu/drivers/media/usb/b2c2/flexcop-usb.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/media/usb/b2c2/flexcop-usb.c	2019-11-29 04:10:32.000000000 -0500
@@ -538,6 +538,9 @@ static int flexcop_usb_probe(struct usb_
 	struct flexcop_device *fc = NULL;
 	int ret;
 
+	if (intf->cur_altsetting->desc.bNumEndpoints < 1)
+		return -ENODEV;
+
 	if ((fc = flexcop_device_kmalloc(sizeof(struct flexcop_usb))) == NULL) {
 		err("out of memory\n");
 		return -ENOMEM;
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/media/usb/dvb-usb/cxusb.c linux-libre-5.4.1-gnu/drivers/media/usb/dvb-usb/cxusb.c
--- linux-libre-5.4-gnu/drivers/media/usb/dvb-usb/cxusb.c	2019-11-24 20:59:26.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/media/usb/dvb-usb/cxusb.c	2019-11-29 06:36:41.000000000 -0500
@@ -521,7 +521,8 @@ static int cxusb_rc_query(struct dvb_usb
 {
 	u8 ircode[4];
 
-	cxusb_ctrl_msg(d, CMD_GET_IR_CODE, NULL, 0, ircode, 4);
+	if (cxusb_ctrl_msg(d, CMD_GET_IR_CODE, NULL, 0, ircode, 4) < 0)
+		return 0;
 
 	if (ircode[2] || ircode[3])
 		rc_keydown(d->rc_dev, RC_PROTO_NEC,
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/media/usb/usbvision/usbvision-video.c linux-libre-5.4.1-gnu/drivers/media/usb/usbvision/usbvision-video.c
--- linux-libre-5.4-gnu/drivers/media/usb/usbvision/usbvision-video.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/media/usb/usbvision/usbvision-video.c	2019-11-29 04:10:32.000000000 -0500
@@ -314,6 +314,10 @@ static int usbvision_v4l2_open(struct fi
 	if (mutex_lock_interruptible(&usbvision->v4l2_lock))
 		return -ERESTARTSYS;
 
+	if (usbvision->remove_pending) {
+		err_code = -ENODEV;
+		goto unlock;
+	}
 	if (usbvision->user) {
 		err_code = -EBUSY;
 	} else {
@@ -377,6 +381,7 @@ unlock:
 static int usbvision_v4l2_close(struct file *file)
 {
 	struct usb_usbvision *usbvision = video_drvdata(file);
+	int r;
 
 	PDEBUG(DBG_IO, "close");
 
@@ -391,9 +396,10 @@ static int usbvision_v4l2_close(struct f
 	usbvision_scratch_free(usbvision);
 
 	usbvision->user--;
+	r = usbvision->remove_pending;
 	mutex_unlock(&usbvision->v4l2_lock);
 
-	if (usbvision->remove_pending) {
+	if (r) {
 		printk(KERN_INFO "%s: Final disconnect\n", __func__);
 		usbvision_release(usbvision);
 		return 0;
@@ -453,6 +459,9 @@ static int vidioc_querycap(struct file *
 {
 	struct usb_usbvision *usbvision = video_drvdata(file);
 
+	if (!usbvision->dev)
+		return -ENODEV;
+
 	strscpy(vc->driver, "USBVision", sizeof(vc->driver));
 	strscpy(vc->card,
 		usbvision_device_data[usbvision->dev_model].model_string,
@@ -1061,6 +1070,11 @@ static int usbvision_radio_open(struct f
 
 	if (mutex_lock_interruptible(&usbvision->v4l2_lock))
 		return -ERESTARTSYS;
+
+	if (usbvision->remove_pending) {
+		err_code = -ENODEV;
+		goto out;
+	}
 	err_code = v4l2_fh_open(file);
 	if (err_code)
 		goto out;
@@ -1093,21 +1107,24 @@ out:
 static int usbvision_radio_close(struct file *file)
 {
 	struct usb_usbvision *usbvision = video_drvdata(file);
+	int r;
 
 	PDEBUG(DBG_IO, "");
 
 	mutex_lock(&usbvision->v4l2_lock);
 	/* Set packet size to 0 */
 	usbvision->iface_alt = 0;
-	usb_set_interface(usbvision->dev, usbvision->iface,
-				    usbvision->iface_alt);
+	if (usbvision->dev)
+		usb_set_interface(usbvision->dev, usbvision->iface,
+				  usbvision->iface_alt);
 
 	usbvision_audio_off(usbvision);
 	usbvision->radio = 0;
 	usbvision->user--;
+	r = usbvision->remove_pending;
 	mutex_unlock(&usbvision->v4l2_lock);
 
-	if (usbvision->remove_pending) {
+	if (r) {
 		printk(KERN_INFO "%s: Final disconnect\n", __func__);
 		v4l2_fh_release(file);
 		usbvision_release(usbvision);
@@ -1539,6 +1556,7 @@ err_usb:
 static void usbvision_disconnect(struct usb_interface *intf)
 {
 	struct usb_usbvision *usbvision = to_usbvision(usb_get_intfdata(intf));
+	int u;
 
 	PDEBUG(DBG_PROBE, "");
 
@@ -1555,13 +1573,14 @@ static void usbvision_disconnect(struct
 	v4l2_device_disconnect(&usbvision->v4l2_dev);
 	usbvision_i2c_unregister(usbvision);
 	usbvision->remove_pending = 1;	/* Now all ISO data will be ignored */
+	u = usbvision->user;
 
 	usb_put_dev(usbvision->dev);
 	usbvision->dev = NULL;	/* USB device is no more */
 
 	mutex_unlock(&usbvision->v4l2_lock);
 
-	if (usbvision->user) {
+	if (u) {
 		printk(KERN_INFO "%s: In use, disconnect pending\n",
 		       __func__);
 		wake_up_interruptible(&usbvision->wait_frame);
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/media/usb/uvc/uvc_driver.c linux-libre-5.4.1-gnu/drivers/media/usb/uvc/uvc_driver.c
--- linux-libre-5.4-gnu/drivers/media/usb/uvc/uvc_driver.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/media/usb/uvc/uvc_driver.c	2019-11-29 04:10:32.000000000 -0500
@@ -2151,6 +2151,20 @@ static int uvc_probe(struct usb_interfac
 			   sizeof(dev->name) - len);
 	}
 
+	/* Initialize the media device. */
+#ifdef CONFIG_MEDIA_CONTROLLER
+	dev->mdev.dev = &intf->dev;
+	strscpy(dev->mdev.model, dev->name, sizeof(dev->mdev.model));
+	if (udev->serial)
+		strscpy(dev->mdev.serial, udev->serial,
+			sizeof(dev->mdev.serial));
+	usb_make_path(udev, dev->mdev.bus_info, sizeof(dev->mdev.bus_info));
+	dev->mdev.hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
+	media_device_init(&dev->mdev);
+
+	dev->vdev.mdev = &dev->mdev;
+#endif
+
 	/* Parse the Video Class control descriptor. */
 	if (uvc_parse_control(dev) < 0) {
 		uvc_trace(UVC_TRACE_PROBE, "Unable to parse UVC "
@@ -2171,19 +2185,7 @@ static int uvc_probe(struct usb_interfac
 			"linux-uvc-devel mailing list.\n");
 	}
 
-	/* Initialize the media device and register the V4L2 device. */
-#ifdef CONFIG_MEDIA_CONTROLLER
-	dev->mdev.dev = &intf->dev;
-	strscpy(dev->mdev.model, dev->name, sizeof(dev->mdev.model));
-	if (udev->serial)
-		strscpy(dev->mdev.serial, udev->serial,
-			sizeof(dev->mdev.serial));
-	usb_make_path(udev, dev->mdev.bus_info, sizeof(dev->mdev.bus_info));
-	dev->mdev.hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
-	media_device_init(&dev->mdev);
-
-	dev->vdev.mdev = &dev->mdev;
-#endif
+	/* Register the V4L2 device. */
 	if (v4l2_device_register(&intf->dev, &dev->vdev) < 0)
 		goto error;
 
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/pci.c linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/pci.c
--- linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/pci.c	2019-11-24 21:13:08.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/pci.c	2019-11-29 06:49:42.000000000 -0500
@@ -3490,7 +3490,7 @@ static int ath10k_pci_probe(struct pci_d
 	struct ath10k_pci *ar_pci;
 	enum ath10k_hw_rev hw_rev;
 	struct ath10k_bus_params bus_params = {};
-	bool pci_ps;
+	bool pci_ps, is_qca988x = false;
 	int (*pci_soft_reset)(struct ath10k *ar);
 	int (*pci_hard_reset)(struct ath10k *ar);
 	u32 (*targ_cpu_to_ce_addr)(struct ath10k *ar, u32 addr);
@@ -3500,6 +3500,7 @@ static int ath10k_pci_probe(struct pci_d
 	case QCA988X_2_0_DEVICE_ID:
 		hw_rev = ATH10K_HW_QCA988X;
 		pci_ps = false;
+		is_qca988x = true;
 		pci_soft_reset = ath10k_pci_warm_reset;
 		pci_hard_reset = ath10k_pci_qca988x_chip_reset;
 		targ_cpu_to_ce_addr = ath10k_pci_qca988x_targ_cpu_to_ce_addr;
@@ -3619,25 +3620,34 @@ static int ath10k_pci_probe(struct pci_d
 		goto err_deinit_irq;
 	}
 
+	bus_params.dev_type = ATH10K_DEV_TYPE_LL;
+	bus_params.link_can_suspend = true;
+	/* Read CHIP_ID before reset to catch QCA9880-AR1A v1 devices that
+	 * fall off the bus during chip_reset. These chips have the same pci
+	 * device id as the QCA9880 BR4A or 2R4E. So that's why the check.
+	 */
+	if (is_qca988x) {
+		bus_params.chip_id =
+			ath10k_pci_soc_read32(ar, SOC_CHIP_ID_ADDRESS);
+		if (bus_params.chip_id != 0xffffffff) {
+			if (!ath10k_pci_chip_is_supported(pdev->device,
+							  bus_params.chip_id))
+				goto err_unsupported;
+		}
+	}
+
 	ret = ath10k_pci_chip_reset(ar);
 	if (ret) {
 		ath10k_err(ar, "failed to reset chip: %d\n", ret);
 		goto err_free_irq;
 	}
 
-	bus_params.dev_type = ATH10K_DEV_TYPE_LL;
-	bus_params.link_can_suspend = true;
 	bus_params.chip_id = ath10k_pci_soc_read32(ar, SOC_CHIP_ID_ADDRESS);
-	if (bus_params.chip_id == 0xffffffff) {
-		ath10k_err(ar, "failed to get chip id\n");
-		goto err_free_irq;
-	}
+	if (bus_params.chip_id == 0xffffffff)
+		goto err_unsupported;
 
-	if (!ath10k_pci_chip_is_supported(pdev->device, bus_params.chip_id)) {
-		ath10k_err(ar, "device %04x with chip_id %08x isn't supported\n",
-			   pdev->device, bus_params.chip_id);
+	if (!ath10k_pci_chip_is_supported(pdev->device, bus_params.chip_id))
 		goto err_free_irq;
-	}
 
 	ret = ath10k_core_register(ar, &bus_params);
 	if (ret) {
@@ -3647,6 +3657,10 @@ static int ath10k_pci_probe(struct pci_d
 
 	return 0;
 
+err_unsupported:
+	ath10k_err(ar, "device %04x with chip_id %08x isn't supported\n",
+		   pdev->device, bus_params.chip_id);
+
 err_free_irq:
 	ath10k_pci_free_irq(ar);
 	ath10k_pci_rx_retry_sync(ar);
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/qmi.c linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/qmi.c
--- linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/qmi.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/qmi.c	2019-11-29 04:10:32.000000000 -0500
@@ -581,22 +581,29 @@ static int ath10k_qmi_host_cap_send_sync
 {
 	struct wlfw_host_cap_resp_msg_v01 resp = {};
 	struct wlfw_host_cap_req_msg_v01 req = {};
+	struct qmi_elem_info *req_ei;
 	struct ath10k *ar = qmi->ar;
+	struct ath10k_snoc *ar_snoc = ath10k_snoc_priv(ar);
 	struct qmi_txn txn;
 	int ret;
 
 	req.daemon_support_valid = 1;
 	req.daemon_support = 0;
 
-	ret = qmi_txn_init(&qmi->qmi_hdl, &txn,
-			   wlfw_host_cap_resp_msg_v01_ei, &resp);
+	ret = qmi_txn_init(&qmi->qmi_hdl, &txn, wlfw_host_cap_resp_msg_v01_ei,
+			   &resp);
 	if (ret < 0)
 		goto out;
 
+	if (test_bit(ATH10K_SNOC_FLAG_8BIT_HOST_CAP_QUIRK, &ar_snoc->flags))
+		req_ei = wlfw_host_cap_8bit_req_msg_v01_ei;
+	else
+		req_ei = wlfw_host_cap_req_msg_v01_ei;
+
 	ret = qmi_send_request(&qmi->qmi_hdl, NULL, &txn,
 			       QMI_WLFW_HOST_CAP_REQ_V01,
 			       WLFW_HOST_CAP_REQ_MSG_V01_MAX_MSG_LEN,
-			       wlfw_host_cap_req_msg_v01_ei, &req);
+			       req_ei, &req);
 	if (ret < 0) {
 		qmi_txn_cancel(&txn);
 		ath10k_err(ar, "failed to send host capability request: %d\n", ret);
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/qmi_wlfw_v01.c linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/qmi_wlfw_v01.c
--- linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/qmi_wlfw_v01.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/qmi_wlfw_v01.c	2019-11-29 04:10:32.000000000 -0500
@@ -1988,6 +1988,28 @@ struct qmi_elem_info wlfw_host_cap_req_m
 	{}
 };
 
+struct qmi_elem_info wlfw_host_cap_8bit_req_msg_v01_ei[] = {
+	{
+		.data_type      = QMI_OPT_FLAG,
+		.elem_len       = 1,
+		.elem_size      = sizeof(u8),
+		.array_type     = NO_ARRAY,
+		.tlv_type       = 0x10,
+		.offset         = offsetof(struct wlfw_host_cap_req_msg_v01,
+					   daemon_support_valid),
+	},
+	{
+		.data_type      = QMI_UNSIGNED_1_BYTE,
+		.elem_len       = 1,
+		.elem_size      = sizeof(u8),
+		.array_type     = NO_ARRAY,
+		.tlv_type       = 0x10,
+		.offset         = offsetof(struct wlfw_host_cap_req_msg_v01,
+					   daemon_support),
+	},
+	{}
+};
+
 struct qmi_elem_info wlfw_host_cap_resp_msg_v01_ei[] = {
 	{
 		.data_type      = QMI_STRUCT,
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/qmi_wlfw_v01.h linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/qmi_wlfw_v01.h
--- linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/qmi_wlfw_v01.h	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/qmi_wlfw_v01.h	2019-11-29 04:10:32.000000000 -0500
@@ -575,6 +575,7 @@ struct wlfw_host_cap_req_msg_v01 {
 
 #define WLFW_HOST_CAP_REQ_MSG_V01_MAX_MSG_LEN 189
 extern struct qmi_elem_info wlfw_host_cap_req_msg_v01_ei[];
+extern struct qmi_elem_info wlfw_host_cap_8bit_req_msg_v01_ei[];
 
 struct wlfw_host_cap_resp_msg_v01 {
 	struct qmi_response_type_v01 resp;
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/snoc.c linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/snoc.c
--- linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/snoc.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/snoc.c	2019-11-29 04:10:32.000000000 -0500
@@ -1261,6 +1261,15 @@ out:
 	return ret;
 }
 
+static void ath10k_snoc_quirks_init(struct ath10k *ar)
+{
+	struct ath10k_snoc *ar_snoc = ath10k_snoc_priv(ar);
+	struct device *dev = &ar_snoc->dev->dev;
+
+	if (of_property_read_bool(dev->of_node, "qcom,snoc-host-cap-8bit-quirk"))
+		set_bit(ATH10K_SNOC_FLAG_8BIT_HOST_CAP_QUIRK, &ar_snoc->flags);
+}
+
 int ath10k_snoc_fw_indication(struct ath10k *ar, u64 type)
 {
 	struct ath10k_snoc *ar_snoc = ath10k_snoc_priv(ar);
@@ -1678,6 +1687,8 @@ static int ath10k_snoc_probe(struct plat
 	ar->ce_priv = &ar_snoc->ce;
 	msa_size = drv_data->msa_size;
 
+	ath10k_snoc_quirks_init(ar);
+
 	ret = ath10k_snoc_resource_init(ar);
 	if (ret) {
 		ath10k_warn(ar, "failed to initialize resource: %d\n", ret);
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/snoc.h linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/snoc.h
--- linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/snoc.h	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/snoc.h	2019-11-29 04:10:32.000000000 -0500
@@ -63,6 +63,7 @@ enum ath10k_snoc_flags {
 	ATH10K_SNOC_FLAG_REGISTERED,
 	ATH10K_SNOC_FLAG_UNREGISTERING,
 	ATH10K_SNOC_FLAG_RECOVERY,
+	ATH10K_SNOC_FLAG_8BIT_HOST_CAP_QUIRK,
 };
 
 struct ath10k_snoc {
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/usb.c linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/usb.c
--- linux-libre-5.4-gnu/drivers/net/wireless/ath/ath10k/usb.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath10k/usb.c	2019-11-29 04:10:32.000000000 -0500
@@ -38,6 +38,10 @@ ath10k_usb_alloc_urb_from_pipe(struct at
 	struct ath10k_urb_context *urb_context = NULL;
 	unsigned long flags;
 
+	/* bail if this pipe is not initialized */
+	if (!pipe->ar_usb)
+		return NULL;
+
 	spin_lock_irqsave(&pipe->ar_usb->cs_lock, flags);
 	if (!list_empty(&pipe->urb_list_head)) {
 		urb_context = list_first_entry(&pipe->urb_list_head,
@@ -55,6 +59,10 @@ static void ath10k_usb_free_urb_to_pipe(
 {
 	unsigned long flags;
 
+	/* bail if this pipe is not initialized */
+	if (!pipe->ar_usb)
+		return;
+
 	spin_lock_irqsave(&pipe->ar_usb->cs_lock, flags);
 
 	pipe->urb_cnt++;
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
--- linux-libre-5.4-gnu/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c	2019-11-29 04:10:32.000000000 -0500
@@ -4183,7 +4183,7 @@ static void ar9003_hw_thermometer_apply(
 
 static void ar9003_hw_thermo_cal_apply(struct ath_hw *ah)
 {
-	u32 data, ko, kg;
+	u32 data = 0, ko, kg;
 
 	if (!AR_SREV_9462_20_OR_LATER(ah))
 		return;
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/staging/comedi/drivers/usbduxfast.c linux-libre-5.4.1-gnu/drivers/staging/comedi/drivers/usbduxfast.c
--- linux-libre-5.4-gnu/drivers/staging/comedi/drivers/usbduxfast.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/staging/comedi/drivers/usbduxfast.c	2019-11-29 04:10:32.000000000 -0500
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- *  Copyright (C) 2004-2014 Bernd Porr, mail@berndporr.me.uk
+ *  Copyright (C) 2004-2019 Bernd Porr, mail@berndporr.me.uk
  */
 
 /*
@@ -8,7 +8,7 @@
  * Description: University of Stirling USB DAQ & INCITE Technology Limited
  * Devices: [ITL] USB-DUX-FAST (usbduxfast)
  * Author: Bernd Porr <mail@berndporr.me.uk>
- * Updated: 10 Oct 2014
+ * Updated: 16 Nov 2019
  * Status: stable
  */
 
@@ -22,6 +22,7 @@
  *
  *
  * Revision history:
+ * 1.0: Fixed a rounding error in usbduxfast_ai_cmdtest
  * 0.9: Dropping the first data packet which seems to be from the last transfer.
  *      Buffer overflows in the FX2 are handed over to comedi.
  * 0.92: Dropping now 4 packets. The quad buffer has to be emptied.
@@ -350,6 +351,7 @@ static int usbduxfast_ai_cmdtest(struct
 				 struct comedi_cmd *cmd)
 {
 	int err = 0;
+	int err2 = 0;
 	unsigned int steps;
 	unsigned int arg;
 
@@ -399,11 +401,16 @@ static int usbduxfast_ai_cmdtest(struct
 	 */
 	steps = (cmd->convert_arg * 30) / 1000;
 	if (cmd->chanlist_len !=  1)
-		err |= comedi_check_trigger_arg_min(&steps,
-						    MIN_SAMPLING_PERIOD);
-	err |= comedi_check_trigger_arg_max(&steps, MAX_SAMPLING_PERIOD);
-	arg = (steps * 1000) / 30;
-	err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg);
+		err2 |= comedi_check_trigger_arg_min(&steps,
+						     MIN_SAMPLING_PERIOD);
+	else
+		err2 |= comedi_check_trigger_arg_min(&steps, 1);
+	err2 |= comedi_check_trigger_arg_max(&steps, MAX_SAMPLING_PERIOD);
+	if (err2) {
+		err |= err2;
+		arg = (steps * 1000) / 30;
+		err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg);
+	}
 
 	if (cmd->stop_src == TRIG_COUNT)
 		err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1);
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/usb/misc/appledisplay.c linux-libre-5.4.1-gnu/drivers/usb/misc/appledisplay.c
--- linux-libre-5.4-gnu/drivers/usb/misc/appledisplay.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/usb/misc/appledisplay.c	2019-11-29 04:10:32.000000000 -0500
@@ -164,7 +164,12 @@ static int appledisplay_bl_get_brightnes
 		0,
 		pdata->msgdata, 2,
 		ACD_USB_TIMEOUT);
-	brightness = pdata->msgdata[1];
+	if (retval < 2) {
+		if (retval >= 0)
+			retval = -EMSGSIZE;
+	} else {
+		brightness = pdata->msgdata[1];
+	}
 	mutex_unlock(&pdata->sysfslock);
 
 	if (retval < 0)
@@ -299,6 +304,7 @@ error:
 	if (pdata) {
 		if (pdata->urb) {
 			usb_kill_urb(pdata->urb);
+			cancel_delayed_work_sync(&pdata->work);
 			if (pdata->urbdata)
 				usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
 					pdata->urbdata, pdata->urb->transfer_dma);
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/usb/misc/chaoskey.c linux-libre-5.4.1-gnu/drivers/usb/misc/chaoskey.c
--- linux-libre-5.4-gnu/drivers/usb/misc/chaoskey.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/usb/misc/chaoskey.c	2019-11-29 04:10:32.000000000 -0500
@@ -384,13 +384,17 @@ static int _chaoskey_fill(struct chaoske
 		!dev->reading,
 		(started ? NAK_TIMEOUT : ALEA_FIRST_TIMEOUT) );
 
-	if (result < 0)
+	if (result < 0) {
+		usb_kill_urb(dev->urb);
 		goto out;
+	}
 
-	if (result == 0)
+	if (result == 0) {
 		result = -ETIMEDOUT;
-	else
+		usb_kill_urb(dev->urb);
+	} else {
 		result = dev->valid;
+	}
 out:
 	/* Let the device go back to sleep eventually */
 	usb_autopm_put_interface(dev->interface);
@@ -526,7 +530,21 @@ static int chaoskey_suspend(struct usb_i
 
 static int chaoskey_resume(struct usb_interface *interface)
 {
+	struct chaoskey *dev;
+	struct usb_device *udev = interface_to_usbdev(interface);
+
 	usb_dbg(interface, "resume");
+	dev = usb_get_intfdata(interface);
+
+	/*
+	 * We may have lost power.
+	 * In that case the device that needs a long time
+	 * for the first requests needs an extended timeout
+	 * again
+	 */
+	if (le16_to_cpu(udev->descriptor.idVendor) == ALEA_VENDOR_ID)
+		dev->reads_started = false;
+
 	return 0;
 }
 #else
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/usb/serial/cp210x.c linux-libre-5.4.1-gnu/drivers/usb/serial/cp210x.c
--- linux-libre-5.4-gnu/drivers/usb/serial/cp210x.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/usb/serial/cp210x.c	2019-11-29 04:10:32.000000000 -0500
@@ -125,6 +125,7 @@ static const struct usb_device_id id_tab
 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
 	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
+	{ USB_DEVICE(0x10C4, 0x83AA) }, /* Mark-10 Digital Force Gauge */
 	{ USB_DEVICE(0x10C4, 0x83D8) }, /* DekTec DTA Plus VHF/UHF Booster/Attenuator */
 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
 	{ USB_DEVICE(0x10C4, 0x8418) }, /* IRZ Automation Teleport SG-10 GSM/GPRS Modem */
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/usb/serial/mos7720.c linux-libre-5.4.1-gnu/drivers/usb/serial/mos7720.c
--- linux-libre-5.4-gnu/drivers/usb/serial/mos7720.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/usb/serial/mos7720.c	2019-11-29 04:10:32.000000000 -0500
@@ -1833,10 +1833,6 @@ static int mos7720_startup(struct usb_se
 	product = le16_to_cpu(serial->dev->descriptor.idProduct);
 	dev = serial->dev;
 
-	/* setting configuration feature to one */
-	usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
-			(__u8)0x03, 0x00, 0x01, 0x00, NULL, 0x00, 5000);
-
 	if (product == MOSCHIP_DEVICE_ID_7715) {
 		struct urb *urb = serial->port[0]->interrupt_in_urb;
 
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/usb/serial/mos7840.c linux-libre-5.4.1-gnu/drivers/usb/serial/mos7840.c
--- linux-libre-5.4-gnu/drivers/usb/serial/mos7840.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/usb/serial/mos7840.c	2019-11-29 04:10:32.000000000 -0500
@@ -119,11 +119,15 @@
 /* This driver also supports
  * ATEN UC2324 device using Moschip MCS7840
  * ATEN UC2322 device using Moschip MCS7820
+ * MOXA UPort 2210 device using Moschip MCS7820
  */
 #define USB_VENDOR_ID_ATENINTL		0x0557
 #define ATENINTL_DEVICE_ID_UC2324	0x2011
 #define ATENINTL_DEVICE_ID_UC2322	0x7820
 
+#define USB_VENDOR_ID_MOXA		0x110a
+#define MOXA_DEVICE_ID_2210		0x2210
+
 /* Interrupt Routine Defines    */
 
 #define SERIAL_IIR_RLS      0x06
@@ -195,6 +199,7 @@ static const struct usb_device_id id_tab
 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USOPTL2_4)},
 	{USB_DEVICE(USB_VENDOR_ID_ATENINTL, ATENINTL_DEVICE_ID_UC2324)},
 	{USB_DEVICE(USB_VENDOR_ID_ATENINTL, ATENINTL_DEVICE_ID_UC2322)},
+	{USB_DEVICE(USB_VENDOR_ID_MOXA, MOXA_DEVICE_ID_2210)},
 	{}			/* terminating entry */
 };
 MODULE_DEVICE_TABLE(usb, id_table);
@@ -2020,6 +2025,7 @@ static int mos7840_probe(struct usb_seri
 				const struct usb_device_id *id)
 {
 	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
+	u16 vid = le16_to_cpu(serial->dev->descriptor.idVendor);
 	u8 *buf;
 	int device_type;
 
@@ -2030,6 +2036,11 @@ static int mos7840_probe(struct usb_seri
 		goto out;
 	}
 
+	if (vid == USB_VENDOR_ID_MOXA && product == MOXA_DEVICE_ID_2210) {
+		device_type = MOSCHIP_DEVICE_ID_7820;
+		goto out;
+	}
+
 	buf = kzalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
@@ -2279,11 +2290,6 @@ out:
 			goto error;
 		} else
 			dev_dbg(&port->dev, "ZLP_REG5 Writing success status%d\n", status);
-
-		/* setting configuration feature to one */
-		usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
-				0x03, 0x00, 0x01, 0x00, NULL, 0x00,
-				MOS_WDR_TIMEOUT);
 	}
 	return 0;
 error:
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/usb/serial/option.c linux-libre-5.4.1-gnu/drivers/usb/serial/option.c
--- linux-libre-5.4-gnu/drivers/usb/serial/option.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/usb/serial/option.c	2019-11-29 04:10:32.000000000 -0500
@@ -197,6 +197,7 @@ static void option_instat_callback(struc
 #define DELL_PRODUCT_5804_MINICARD_ATT		0x819b  /* Novatel E371 */
 
 #define DELL_PRODUCT_5821E			0x81d7
+#define DELL_PRODUCT_5821E_ESIM			0x81e0
 
 #define KYOCERA_VENDOR_ID			0x0c88
 #define KYOCERA_PRODUCT_KPC650			0x17da
@@ -1044,6 +1045,8 @@ static const struct usb_device_id option
 	{ USB_DEVICE_AND_INTERFACE_INFO(DELL_VENDOR_ID, DELL_PRODUCT_5804_MINICARD_ATT, 0xff, 0xff, 0xff) },
 	{ USB_DEVICE(DELL_VENDOR_ID, DELL_PRODUCT_5821E),
 	  .driver_info = RSVD(0) | RSVD(1) | RSVD(6) },
+	{ USB_DEVICE(DELL_VENDOR_ID, DELL_PRODUCT_5821E_ESIM),
+	  .driver_info = RSVD(0) | RSVD(1) | RSVD(6) },
 	{ USB_DEVICE(ANYDATA_VENDOR_ID, ANYDATA_PRODUCT_ADU_E100A) },	/* ADU-E100, ADU-310 */
 	{ USB_DEVICE(ANYDATA_VENDOR_ID, ANYDATA_PRODUCT_ADU_500A) },
 	{ USB_DEVICE(ANYDATA_VENDOR_ID, ANYDATA_PRODUCT_ADU_620UW) },
@@ -1990,6 +1993,10 @@ static const struct usb_device_id option
 	{ USB_DEVICE_AND_INTERFACE_INFO(0x03f0, 0xa31d, 0xff, 0x06, 0x13) },
 	{ USB_DEVICE_AND_INTERFACE_INFO(0x03f0, 0xa31d, 0xff, 0x06, 0x14) },
 	{ USB_DEVICE_AND_INTERFACE_INFO(0x03f0, 0xa31d, 0xff, 0x06, 0x1b) },
+	{ USB_DEVICE(0x0489, 0xe0b4),						/* Foxconn T77W968 */
+	  .driver_info = RSVD(0) | RSVD(1) | RSVD(6) },
+	{ USB_DEVICE(0x0489, 0xe0b5),						/* Foxconn T77W968 ESIM */
+	  .driver_info = RSVD(0) | RSVD(1) | RSVD(6) },
 	{ USB_DEVICE(0x1508, 0x1001),						/* Fibocom NL668 */
 	  .driver_info = RSVD(4) | RSVD(5) | RSVD(6) },
 	{ USB_DEVICE(0x2cb7, 0x0104),						/* Fibocom NL678 series */
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/usb/usbip/Kconfig linux-libre-5.4.1-gnu/drivers/usb/usbip/Kconfig
--- linux-libre-5.4-gnu/drivers/usb/usbip/Kconfig	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/usb/usbip/Kconfig	2019-11-29 04:10:32.000000000 -0500
@@ -4,6 +4,7 @@ config USBIP_CORE
 	tristate "USB/IP support"
 	depends on NET
 	select USB_COMMON
+	select SGL_ALLOC
 	---help---
 	  This enables pushing USB packets over IP to allow remote
 	  machines direct access to USB devices. It provides the
diff -druNp --no-dereference linux-libre-5.4-gnu/drivers/usb/usbip/stub_rx.c linux-libre-5.4.1-gnu/drivers/usb/usbip/stub_rx.c
--- linux-libre-5.4-gnu/drivers/usb/usbip/stub_rx.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/drivers/usb/usbip/stub_rx.c	2019-11-29 04:10:32.000000000 -0500
@@ -470,18 +470,50 @@ static void stub_recv_cmd_submit(struct
 	if (pipe == -1)
 		return;
 
+	/*
+	 * Smatch reported the error case where use_sg is true and buf_len is 0.
+	 * In this case, It adds SDEV_EVENT_ERROR_MALLOC and stub_priv will be
+	 * released by stub event handler and connection will be shut down.
+	 */
 	priv = stub_priv_alloc(sdev, pdu);
 	if (!priv)
 		return;
 
 	buf_len = (unsigned long long)pdu->u.cmd_submit.transfer_buffer_length;
 
+	if (use_sg && !buf_len) {
+		dev_err(&udev->dev, "sg buffer with zero length\n");
+		goto err_malloc;
+	}
+
 	/* allocate urb transfer buffer, if needed */
 	if (buf_len) {
 		if (use_sg) {
 			sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents);
 			if (!sgl)
 				goto err_malloc;
+
+			/* Check if the server's HCD supports SG */
+			if (!udev->bus->sg_tablesize) {
+				/*
+				 * If the server's HCD doesn't support SG, break
+				 * a single SG request into several URBs and map
+				 * each SG list entry to corresponding URB
+				 * buffer. The previously allocated SG list is
+				 * stored in priv->sgl (If the server's HCD
+				 * support SG, SG list is stored only in
+				 * urb->sg) and it is used as an indicator that
+				 * the server split single SG request into
+				 * several URBs. Later, priv->sgl is used by
+				 * stub_complete() and stub_send_ret_submit() to
+				 * reassemble the divied URBs.
+				 */
+				support_sg = 0;
+				num_urbs = nents;
+				priv->completed_urbs = 0;
+				pdu->u.cmd_submit.transfer_flags &=
+								~URB_DMA_MAP_SG;
+			}
 		} else {
 			buffer = kzalloc(buf_len, GFP_KERNEL);
 			if (!buffer)
@@ -489,24 +521,6 @@ static void stub_recv_cmd_submit(struct
 		}
 	}
 
-	/* Check if the server's HCD supports SG */
-	if (use_sg && !udev->bus->sg_tablesize) {
-		/*
-		 * If the server's HCD doesn't support SG, break a single SG
-		 * request into several URBs and map each SG list entry to
-		 * corresponding URB buffer. The previously allocated SG
-		 * list is stored in priv->sgl (If the server's HCD support SG,
-		 * SG list is stored only in urb->sg) and it is used as an
-		 * indicator that the server split single SG request into
-		 * several URBs. Later, priv->sgl is used by stub_complete() and
-		 * stub_send_ret_submit() to reassemble the divied URBs.
-		 */
-		support_sg = 0;
-		num_urbs = nents;
-		priv->completed_urbs = 0;
-		pdu->u.cmd_submit.transfer_flags &= ~URB_DMA_MAP_SG;
-	}
-
 	/* allocate urb array */
 	priv->num_urbs = num_urbs;
 	priv->urbs = kmalloc_array(num_urbs, sizeof(*priv->urbs), GFP_KERNEL);
diff -druNp --no-dereference linux-libre-5.4-gnu/fs/exec.c linux-libre-5.4.1-gnu/fs/exec.c
--- linux-libre-5.4-gnu/fs/exec.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/fs/exec.c	2019-11-29 04:10:32.000000000 -0500
@@ -1015,7 +1015,7 @@ static int exec_mmap(struct mm_struct *m
 	/* Notify parent that we're no longer interested in the old VM */
 	tsk = current;
 	old_mm = current->mm;
-	mm_release(tsk, old_mm);
+	exec_mm_release(tsk, old_mm);
 
 	if (old_mm) {
 		sync_mm_rss(old_mm);
diff -druNp --no-dereference linux-libre-5.4-gnu/include/linux/compat.h linux-libre-5.4.1-gnu/include/linux/compat.h
--- linux-libre-5.4-gnu/include/linux/compat.h	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/include/linux/compat.h	2019-11-29 04:10:32.000000000 -0500
@@ -410,8 +410,6 @@ struct compat_kexec_segment;
 struct compat_mq_attr;
 struct compat_msgbuf;
 
-extern void compat_exit_robust_list(struct task_struct *curr);
-
 #define BITS_PER_COMPAT_LONG    (8*sizeof(compat_long_t))
 
 #define BITS_TO_COMPAT_LONGS(bits) DIV_ROUND_UP(bits, BITS_PER_COMPAT_LONG)
diff -druNp --no-dereference linux-libre-5.4-gnu/include/linux/futex.h linux-libre-5.4.1-gnu/include/linux/futex.h
--- linux-libre-5.4-gnu/include/linux/futex.h	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/include/linux/futex.h	2019-11-29 04:10:32.000000000 -0500
@@ -2,7 +2,9 @@
 #ifndef _LINUX_FUTEX_H
 #define _LINUX_FUTEX_H
 
+#include <linux/sched.h>
 #include <linux/ktime.h>
+
 #include <uapi/linux/futex.h>
 
 struct inode;
@@ -48,15 +50,35 @@ union futex_key {
 #define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = NULL } }
 
 #ifdef CONFIG_FUTEX
-extern void exit_robust_list(struct task_struct *curr);
+enum {
+	FUTEX_STATE_OK,
+	FUTEX_STATE_EXITING,
+	FUTEX_STATE_DEAD,
+};
 
-long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
-	      u32 __user *uaddr2, u32 val2, u32 val3);
-#else
-static inline void exit_robust_list(struct task_struct *curr)
+static inline void futex_init_task(struct task_struct *tsk)
 {
+	tsk->robust_list = NULL;
+#ifdef CONFIG_COMPAT
+	tsk->compat_robust_list = NULL;
+#endif
+	INIT_LIST_HEAD(&tsk->pi_state_list);
+	tsk->pi_state_cache = NULL;
+	tsk->futex_state = FUTEX_STATE_OK;
+	mutex_init(&tsk->futex_exit_mutex);
 }
 
+void futex_exit_recursive(struct task_struct *tsk);
+void futex_exit_release(struct task_struct *tsk);
+void futex_exec_release(struct task_struct *tsk);
+
+long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
+	      u32 __user *uaddr2, u32 val2, u32 val3);
+#else
+static inline void futex_init_task(struct task_struct *tsk) { }
+static inline void futex_exit_recursive(struct task_struct *tsk) { }
+static inline void futex_exit_release(struct task_struct *tsk) { }
+static inline void futex_exec_release(struct task_struct *tsk) { }
 static inline long do_futex(u32 __user *uaddr, int op, u32 val,
 			    ktime_t *timeout, u32 __user *uaddr2,
 			    u32 val2, u32 val3)
@@ -65,12 +87,4 @@ static inline long do_futex(u32 __user *
 }
 #endif
 
-#ifdef CONFIG_FUTEX_PI
-extern void exit_pi_state_list(struct task_struct *curr);
-#else
-static inline void exit_pi_state_list(struct task_struct *curr)
-{
-}
-#endif
-
 #endif
diff -druNp --no-dereference linux-libre-5.4-gnu/include/linux/sched/mm.h linux-libre-5.4.1-gnu/include/linux/sched/mm.h
--- linux-libre-5.4-gnu/include/linux/sched/mm.h	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/include/linux/sched/mm.h	2019-11-29 04:10:32.000000000 -0500
@@ -117,8 +117,10 @@ extern struct mm_struct *get_task_mm(str
  * succeeds.
  */
 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
-/* Remove the current tasks stale references to the old mm_struct */
-extern void mm_release(struct task_struct *, struct mm_struct *);
+/* Remove the current tasks stale references to the old mm_struct on exit() */
+extern void exit_mm_release(struct task_struct *, struct mm_struct *);
+/* Remove the current tasks stale references to the old mm_struct on exec() */
+extern void exec_mm_release(struct task_struct *, struct mm_struct *);
 
 #ifdef CONFIG_MEMCG
 extern void mm_update_next_owner(struct mm_struct *mm);
diff -druNp --no-dereference linux-libre-5.4-gnu/include/linux/sched.h linux-libre-5.4.1-gnu/include/linux/sched.h
--- linux-libre-5.4-gnu/include/linux/sched.h	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/include/linux/sched.h	2019-11-29 04:10:32.000000000 -0500
@@ -1054,6 +1054,8 @@ struct task_struct {
 #endif
 	struct list_head		pi_state_list;
 	struct futex_pi_state		*pi_state_cache;
+	struct mutex			futex_exit_mutex;
+	unsigned int			futex_state;
 #endif
 #ifdef CONFIG_PERF_EVENTS
 	struct perf_event_context	*perf_event_ctxp[perf_nr_task_contexts];
@@ -1442,7 +1444,6 @@ extern struct pid *cad_pid;
  */
 #define PF_IDLE			0x00000002	/* I am an IDLE thread */
 #define PF_EXITING		0x00000004	/* Getting shut down */
-#define PF_EXITPIDONE		0x00000008	/* PI exit done on shut down */
 #define PF_VCPU			0x00000010	/* I'm a virtual CPU */
 #define PF_WQ_WORKER		0x00000020	/* I'm a workqueue worker */
 #define PF_FORKNOEXEC		0x00000040	/* Forked but didn't exec */
diff -druNp --no-dereference linux-libre-5.4-gnu/kernel/exit.c linux-libre-5.4.1-gnu/kernel/exit.c
--- linux-libre-5.4-gnu/kernel/exit.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/kernel/exit.c	2019-11-29 04:10:32.000000000 -0500
@@ -437,7 +437,7 @@ static void exit_mm(void)
 	struct mm_struct *mm = current->mm;
 	struct core_state *core_state;
 
-	mm_release(current, mm);
+	exit_mm_release(current, mm);
 	if (!mm)
 		return;
 	sync_mm_rss(mm);
@@ -746,32 +746,12 @@ void __noreturn do_exit(long code)
 	 */
 	if (unlikely(tsk->flags & PF_EXITING)) {
 		pr_alert("Fixing recursive fault but reboot is needed!\n");
-		/*
-		 * We can do this unlocked here. The futex code uses
-		 * this flag just to verify whether the pi state
-		 * cleanup has been done or not. In the worst case it
-		 * loops once more. We pretend that the cleanup was
-		 * done as there is no way to return. Either the
-		 * OWNER_DIED bit is set by now or we push the blocked
-		 * task into the wait for ever nirwana as well.
-		 */
-		tsk->flags |= PF_EXITPIDONE;
+		futex_exit_recursive(tsk);
 		set_current_state(TASK_UNINTERRUPTIBLE);
 		schedule();
 	}
 
 	exit_signals(tsk);  /* sets PF_EXITING */
-	/*
-	 * Ensure that all new tsk->pi_lock acquisitions must observe
-	 * PF_EXITING. Serializes against futex.c:attach_to_pi_owner().
-	 */
-	smp_mb();
-	/*
-	 * Ensure that we must observe the pi_state in exit_mm() ->
-	 * mm_release() -> exit_pi_state_list().
-	 */
-	raw_spin_lock_irq(&tsk->pi_lock);
-	raw_spin_unlock_irq(&tsk->pi_lock);
 
 	if (unlikely(in_atomic())) {
 		pr_info("note: %s[%d] exited with preempt_count %d\n",
@@ -846,12 +826,6 @@ void __noreturn do_exit(long code)
 	 * Make sure we are holding no locks:
 	 */
 	debug_check_no_locks_held();
-	/*
-	 * We can do this unlocked here. The futex code uses this flag
-	 * just to verify whether the pi state cleanup has been done
-	 * or not. In the worst case it loops once more.
-	 */
-	tsk->flags |= PF_EXITPIDONE;
 
 	if (tsk->io_context)
 		exit_io_context(tsk);
diff -druNp --no-dereference linux-libre-5.4-gnu/kernel/fork.c linux-libre-5.4.1-gnu/kernel/fork.c
--- linux-libre-5.4-gnu/kernel/fork.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/kernel/fork.c	2019-11-29 04:10:32.000000000 -0500
@@ -1283,24 +1283,8 @@ static int wait_for_vfork_done(struct ta
  * restoring the old one. . .
  * Eric Biederman 10 January 1998
  */
-void mm_release(struct task_struct *tsk, struct mm_struct *mm)
+static void mm_release(struct task_struct *tsk, struct mm_struct *mm)
 {
-	/* Get rid of any futexes when releasing the mm */
-#ifdef CONFIG_FUTEX
-	if (unlikely(tsk->robust_list)) {
-		exit_robust_list(tsk);
-		tsk->robust_list = NULL;
-	}
-#ifdef CONFIG_COMPAT
-	if (unlikely(tsk->compat_robust_list)) {
-		compat_exit_robust_list(tsk);
-		tsk->compat_robust_list = NULL;
-	}
-#endif
-	if (unlikely(!list_empty(&tsk->pi_state_list)))
-		exit_pi_state_list(tsk);
-#endif
-
 	uprobe_free_utask(tsk);
 
 	/* Get rid of any cached register state */
@@ -1333,6 +1317,18 @@ void mm_release(struct task_struct *tsk,
 		complete_vfork_done(tsk);
 }
 
+void exit_mm_release(struct task_struct *tsk, struct mm_struct *mm)
+{
+	futex_exit_release(tsk);
+	mm_release(tsk, mm);
+}
+
+void exec_mm_release(struct task_struct *tsk, struct mm_struct *mm)
+{
+	futex_exec_release(tsk);
+	mm_release(tsk, mm);
+}
+
 /**
  * dup_mm() - duplicates an existing mm structure
  * @tsk: the task_struct with which the new mm will be associated.
@@ -2062,14 +2058,8 @@ static __latent_entropy struct task_stru
 #ifdef CONFIG_BLOCK
 	p->plug = NULL;
 #endif
-#ifdef CONFIG_FUTEX
-	p->robust_list = NULL;
-#ifdef CONFIG_COMPAT
-	p->compat_robust_list = NULL;
-#endif
-	INIT_LIST_HEAD(&p->pi_state_list);
-	p->pi_state_cache = NULL;
-#endif
+	futex_init_task(p);
+
 	/*
 	 * sigaltstack should be cleared when sharing the same VM
 	 */
diff -druNp --no-dereference linux-libre-5.4-gnu/kernel/futex.c linux-libre-5.4.1-gnu/kernel/futex.c
--- linux-libre-5.4-gnu/kernel/futex.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/kernel/futex.c	2019-11-29 04:10:32.000000000 -0500
@@ -325,6 +325,12 @@ static inline bool should_fail_futex(boo
 }
 #endif /* CONFIG_FAIL_FUTEX */
 
+#ifdef CONFIG_COMPAT
+static void compat_exit_robust_list(struct task_struct *curr);
+#else
+static inline void compat_exit_robust_list(struct task_struct *curr) { }
+#endif
+
 static inline void futex_get_mm(union futex_key *key)
 {
 	mmgrab(key->private.mm);
@@ -890,7 +896,7 @@ static void put_pi_state(struct futex_pi
  * Kernel cleans up PI-state, but userspace is likely hosed.
  * (Robust-futex cleanup is separate and might save the day for userspace.)
  */
-void exit_pi_state_list(struct task_struct *curr)
+static void exit_pi_state_list(struct task_struct *curr)
 {
 	struct list_head *next, *head = &curr->pi_state_list;
 	struct futex_pi_state *pi_state;
@@ -960,7 +966,8 @@ void exit_pi_state_list(struct task_stru
 	}
 	raw_spin_unlock_irq(&curr->pi_lock);
 }
-
+#else
+static inline void exit_pi_state_list(struct task_struct *curr) { }
 #endif
 
 /*
@@ -1169,16 +1176,47 @@ out_error:
 	return ret;
 }
 
+/**
+ * wait_for_owner_exiting - Block until the owner has exited
+ * @exiting:	Pointer to the exiting task
+ *
+ * Caller must hold a refcount on @exiting.
+ */
+static void wait_for_owner_exiting(int ret, struct task_struct *exiting)
+{
+	if (ret != -EBUSY) {
+		WARN_ON_ONCE(exiting);
+		return;
+	}
+
+	if (WARN_ON_ONCE(ret == -EBUSY && !exiting))
+		return;
+
+	mutex_lock(&exiting->futex_exit_mutex);
+	/*
+	 * No point in doing state checking here. If the waiter got here
+	 * while the task was in exec()->exec_futex_release() then it can
+	 * have any FUTEX_STATE_* value when the waiter has acquired the
+	 * mutex. OK, if running, EXITING or DEAD if it reached exit()
+	 * already. Highly unlikely and not a problem. Just one more round
+	 * through the futex maze.
+	 */
+	mutex_unlock(&exiting->futex_exit_mutex);
+
+	put_task_struct(exiting);
+}
+
 static int handle_exit_race(u32 __user *uaddr, u32 uval,
 			    struct task_struct *tsk)
 {
 	u32 uval2;
 
 	/*
-	 * If PF_EXITPIDONE is not yet set, then try again.
+	 * If the futex exit state is not yet FUTEX_STATE_DEAD, tell the
+	 * caller that the alleged owner is busy.
 	 */
-	if (tsk && !(tsk->flags & PF_EXITPIDONE))
-		return -EAGAIN;
+	if (tsk && tsk->futex_state != FUTEX_STATE_DEAD)
+		return -EBUSY;
 
 	/*
 	 * Reread the user space value to handle the following situation:
@@ -1196,8 +1234,9 @@ static int handle_exit_race(u32 __user *
 	 *    *uaddr = 0xC0000000;	     tsk = get_task(PID);
 	 *   }				     if (!tsk->flags & PF_EXITING) {
 	 *  ...				       attach();
-	 *  tsk->flags |= PF_EXITPIDONE;     } else {
-	 *				       if (!(tsk->flags & PF_EXITPIDONE))
+	 *  tsk->futex_state =               } else {
+	 *	FUTEX_STATE_DEAD;              if (tsk->futex_state !=
+	 *					  FUTEX_STATE_DEAD)
 	 *				         return -EAGAIN;
 	 *				       return -ESRCH; <--- FAIL
 	 *				     }
@@ -1228,7 +1267,8 @@ static int handle_exit_race(u32 __user *
  * it after doing proper sanity checks.
  */
 static int attach_to_pi_owner(u32 __user *uaddr, u32 uval, union futex_key *key,
-			      struct futex_pi_state **ps)
+			      struct futex_pi_state **ps,
+			      struct task_struct **exiting)
 {
 	pid_t pid = uval & FUTEX_TID_MASK;
 	struct futex_pi_state *pi_state;
@@ -1253,22 +1293,33 @@ static int attach_to_pi_owner(u32 __user
 	}
 
 	/*
-	 * We need to look at the task state flags to figure out,
-	 * whether the task is exiting. To protect against the do_exit
-	 * change of the task flags, we do this protected by
-	 * p->pi_lock:
+	 * We need to look at the task state to figure out, whether the
+	 * task is exiting. To protect against the change of the task state
+	 * in futex_exit_release(), we do this protected by p->pi_lock:
 	 */
 	raw_spin_lock_irq(&p->pi_lock);
-	if (unlikely(p->flags & PF_EXITING)) {
+	if (unlikely(p->futex_state != FUTEX_STATE_OK)) {
 		/*
-		 * The task is on the way out. When PF_EXITPIDONE is
-		 * set, we know that the task has finished the
-		 * cleanup:
+		 * The task is on the way out. When the futex state is
+		 * FUTEX_STATE_DEAD, we know that the task has finished
+		 * the cleanup:
 		 */
 		int ret = handle_exit_race(uaddr, uval, p);
 
 		raw_spin_unlock_irq(&p->pi_lock);
-		put_task_struct(p);
+		/*
+		 * If the owner task is between FUTEX_STATE_EXITING and
+		 * FUTEX_STATE_DEAD then store the task pointer and keep
+		 * the reference on the task struct. The calling code will
+		 * drop all locks, wait for the task to reach
+		 * FUTEX_STATE_DEAD and then drop the refcount. This is
+		 * required to prevent a live lock when the current task
+		 * preempted the exiting task between the two states.
+		 */
+		if (ret == -EBUSY)
+			*exiting = p;
+		else
+			put_task_struct(p);
 		return ret;
 	}
 
@@ -1307,7 +1358,8 @@ static int attach_to_pi_owner(u32 __user
 
 static int lookup_pi_state(u32 __user *uaddr, u32 uval,
 			   struct futex_hash_bucket *hb,
-			   union futex_key *key, struct futex_pi_state **ps)
+			   union futex_key *key, struct futex_pi_state **ps,
+			   struct task_struct **exiting)
 {
 	struct futex_q *top_waiter = futex_top_waiter(hb, key);
 
@@ -1322,7 +1374,7 @@ static int lookup_pi_state(u32 __user *u
 	 * We are the first waiter - try to look up the owner based on
 	 * @uval and attach to it.
 	 */
-	return attach_to_pi_owner(uaddr, uval, key, ps);
+	return attach_to_pi_owner(uaddr, uval, key, ps, exiting);
 }
 
 static int lock_pi_update_atomic(u32 __user *uaddr, u32 uval, u32 newval)
@@ -1350,6 +1402,8 @@ static int lock_pi_update_atomic(u32 __u
  *			lookup
  * @task:		the task to perform the atomic lock work for.  This will
  *			be "current" except in the case of requeue pi.
+ * @exiting:		Pointer to store the task pointer of the owner task
+ *			which is in the middle of exiting
  * @set_waiters:	force setting the FUTEX_WAITERS bit (1) or not (0)
  *
  * Return:
@@ -1358,11 +1412,17 @@ static int lock_pi_update_atomic(u32 __u
  *  - <0 - error
  *
  * The hb->lock and futex_key refs shall be held by the caller.
+ *
+ * @exiting is only set when the return value is -EBUSY. If so, this holds
+ * a refcount on the exiting task on return and the caller needs to drop it
+ * after waiting for the exit to complete.
  */
 static int futex_lock_pi_atomic(u32 __user *uaddr, struct futex_hash_bucket *hb,
 				union futex_key *key,
 				struct futex_pi_state **ps,
-				struct task_struct *task, int set_waiters)
+				struct task_struct *task,
+				struct task_struct **exiting,
+				int set_waiters)
 {
 	u32 uval, newval, vpid = task_pid_vnr(task);
 	struct futex_q *top_waiter;
@@ -1432,7 +1492,7 @@ static int futex_lock_pi_atomic(u32 __us
 	 * attach to the owner. If that fails, no harm done, we only
 	 * set the FUTEX_WAITERS bit in the user space variable.
 	 */
-	return attach_to_pi_owner(uaddr, newval, key, ps);
+	return attach_to_pi_owner(uaddr, newval, key, ps, exiting);
 }
 
 /**
@@ -1850,6 +1910,8 @@ void requeue_pi_wake_futex(struct futex_
  * @key1:		the from futex key
  * @key2:		the to futex key
  * @ps:			address to store the pi_state pointer
+ * @exiting:		Pointer to store the task pointer of the owner task
+ *			which is in the middle of exiting
  * @set_waiters:	force setting the FUTEX_WAITERS bit (1) or not (0)
  *
  * Try and get the lock on behalf of the top waiter if we can do it atomically.
@@ -1857,16 +1919,20 @@ void requeue_pi_wake_futex(struct futex_
  * then direct futex_lock_pi_atomic() to force setting the FUTEX_WAITERS bit.
  * hb1 and hb2 must be held by the caller.
  *
+ * @exiting is only set when the return value is -EBUSY. If so, this holds
+ * a refcount on the exiting task on return and the caller needs to drop it
+ * after waiting for the exit to complete.
+ *
  * Return:
  *  -  0 - failed to acquire the lock atomically;
  *  - >0 - acquired the lock, return value is vpid of the top_waiter
  *  - <0 - error
  */
-static int futex_proxy_trylock_atomic(u32 __user *pifutex,
-				 struct futex_hash_bucket *hb1,
-				 struct futex_hash_bucket *hb2,
-				 union futex_key *key1, union futex_key *key2,
-				 struct futex_pi_state **ps, int set_waiters)
+static int
+futex_proxy_trylock_atomic(u32 __user *pifutex, struct futex_hash_bucket *hb1,
+			   struct futex_hash_bucket *hb2, union futex_key *key1,
+			   union futex_key *key2, struct futex_pi_state **ps,
+			   struct task_struct **exiting, int set_waiters)
 {
 	struct futex_q *top_waiter = NULL;
 	u32 curval;
@@ -1903,7 +1969,7 @@ static int futex_proxy_trylock_atomic(u3
 	 */
 	vpid = task_pid_vnr(top_waiter->task);
 	ret = futex_lock_pi_atomic(pifutex, hb2, key2, ps, top_waiter->task,
-				   set_waiters);
+				   exiting, set_waiters);
 	if (ret == 1) {
 		requeue_pi_wake_futex(top_waiter, key2, hb2);
 		return vpid;
@@ -2032,6 +2098,8 @@ retry_private:
 	}
 
 	if (requeue_pi && (task_count - nr_wake < nr_requeue)) {
+		struct task_struct *exiting = NULL;
+
 		/*
 		 * Attempt to acquire uaddr2 and wake the top waiter. If we
 		 * intend to requeue waiters, force setting the FUTEX_WAITERS
@@ -2039,7 +2107,8 @@ retry_private:
 		 * faults rather in the requeue loop below.
 		 */
 		ret = futex_proxy_trylock_atomic(uaddr2, hb1, hb2, &key1,
-						 &key2, &pi_state, nr_requeue);
+						 &key2, &pi_state,
+						 &exiting, nr_requeue);
 
 		/*
 		 * At this point the top_waiter has either taken uaddr2 or is
@@ -2066,7 +2135,8 @@ retry_private:
 			 * If that call succeeds then we have pi_state and an
 			 * initial refcount on it.
 			 */
-			ret = lookup_pi_state(uaddr2, ret, hb2, &key2, &pi_state);
+			ret = lookup_pi_state(uaddr2, ret, hb2, &key2,
+					      &pi_state, &exiting);
 		}
 
 		switch (ret) {
@@ -2084,17 +2154,24 @@ retry_private:
 			if (!ret)
 				goto retry;
 			goto out;
+		case -EBUSY:
 		case -EAGAIN:
 			/*
 			 * Two reasons for this:
-			 * - Owner is exiting and we just wait for the
+			 * - EBUSY: Owner is exiting and we just wait for the
 			 *   exit to complete.
-			 * - The user space value changed.
+			 * - EAGAIN: The user space value changed.
 			 */
 			double_unlock_hb(hb1, hb2);
 			hb_waiters_dec(hb2);
 			put_futex_key(&key2);
 			put_futex_key(&key1);
+			/*
+			 * Handle the case where the owner is in the middle of
+			 * exiting. Wait for the exit to complete otherwise
+			 * this task might loop forever, aka. live lock.
+			 */
+			wait_for_owner_exiting(ret, exiting);
 			cond_resched();
 			goto retry;
 		default:
@@ -2801,6 +2878,7 @@ static int futex_lock_pi(u32 __user *uad
 {
 	struct hrtimer_sleeper timeout, *to;
 	struct futex_pi_state *pi_state = NULL;
+	struct task_struct *exiting = NULL;
 	struct rt_mutex_waiter rt_waiter;
 	struct futex_hash_bucket *hb;
 	struct futex_q q = futex_q_init;
@@ -2822,7 +2900,8 @@ retry:
 retry_private:
 	hb = queue_lock(&q);
 
-	ret = futex_lock_pi_atomic(uaddr, hb, &q.key, &q.pi_state, current, 0);
+	ret = futex_lock_pi_atomic(uaddr, hb, &q.key, &q.pi_state, current,
+				   &exiting, 0);
 	if (unlikely(ret)) {
 		/*
 		 * Atomic work succeeded and we got the lock,
@@ -2835,15 +2914,22 @@ retry_private:
 			goto out_unlock_put_key;
 		case -EFAULT:
 			goto uaddr_faulted;
+		case -EBUSY:
 		case -EAGAIN:
 			/*
 			 * Two reasons for this:
-			 * - Task is exiting and we just wait for the
+			 * - EBUSY: Task is exiting and we just wait for the
 			 *   exit to complete.
-			 * - The user space value changed.
+			 * - EAGAIN: The user space value changed.
 			 */
 			queue_unlock(hb);
 			put_futex_key(&q.key);
+			/*
+			 * Handle the case where the owner is in the middle of
+			 * exiting. Wait for the exit to complete otherwise
+			 * this task might loop forever, aka. live lock.
+			 */
+			wait_for_owner_exiting(ret, exiting);
 			cond_resched();
 			goto retry;
 		default:
@@ -3452,11 +3538,16 @@ err_unlock:
 	return ret;
 }
 
+/* Constants for the pending_op argument of handle_futex_death */
+#define HANDLE_DEATH_PENDING	true
+#define HANDLE_DEATH_LIST	false
+
 /*
  * Process a futex-list entry, check whether it's owned by the
  * dying task, and do notification if so:
  */
-static int handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi)
+static int handle_futex_death(u32 __user *uaddr, struct task_struct *curr,
+			      bool pi, bool pending_op)
 {
 	u32 uval, uninitialized_var(nval), mval;
 	int err;
@@ -3469,6 +3560,42 @@ retry:
 	if (get_user(uval, uaddr))
 		return -1;
 
+	/*
+	 * Special case for regular (non PI) futexes. The unlock path in
+	 * user space has two race scenarios:
+	 *
+	 * 1. The unlock path releases the user space futex value and
+	 *    before it can execute the futex() syscall to wake up
+	 *    waiters it is killed.
+	 *
+	 * 2. A woken up waiter is killed before it can acquire the
+	 *    futex in user space.
+	 *
+	 * In both cases the TID validation below prevents a wakeup of
+	 * potential waiters which can cause these waiters to block
+	 * forever.
+	 *
+	 * In both cases the following conditions are met:
+	 *
+	 *	1) task->robust_list->list_op_pending != NULL
+	 *	   @pending_op == true
+	 *	2) User space futex value == 0
+	 *	3) Regular futex: @pi == false
+	 *
+	 * If these conditions are met, it is safe to attempt waking up a
+	 * potential waiter without touching the user space futex value and
+	 * trying to set the OWNER_DIED bit. The user space futex value is
+	 * uncontended and the rest of the user space mutex state is
+	 * consistent, so a woken waiter will just take over the
+	 * uncontended futex. Setting the OWNER_DIED bit would create
+	 * inconsistent state and malfunction of the user space owner died
+	 * handling.
+	 */
+	if (pending_op && !pi && !uval) {
+		futex_wake(uaddr, 1, 1, FUTEX_BITSET_MATCH_ANY);
+		return 0;
+	}
+
 	if ((uval & FUTEX_TID_MASK) != task_pid_vnr(curr))
 		return 0;
 
@@ -3547,7 +3674,7 @@ static inline int fetch_robust_entry(str
  *
  * We silently return on any sign of list-walking problem.
  */
-void exit_robust_list(struct task_struct *curr)
+static void exit_robust_list(struct task_struct *curr)
 {
 	struct robust_list_head __user *head = curr->robust_list;
 	struct robust_list __user *entry, *next_entry, *pending;
@@ -3588,10 +3715,11 @@ void exit_robust_list(struct task_struct
 		 * A pending lock might already be on the list, so
 		 * don't process it twice:
 		 */
-		if (entry != pending)
+		if (entry != pending) {
 			if (handle_futex_death((void __user *)entry + futex_offset,
-						curr, pi))
+						curr, pi, HANDLE_DEATH_LIST))
 				return;
+		}
 		if (rc)
 			return;
 		entry = next_entry;
@@ -3605,9 +3733,118 @@ void exit_robust_list(struct task_struct
 		cond_resched();
 	}
 
-	if (pending)
+	if (pending) {
 		handle_futex_death((void __user *)pending + futex_offset,
-				   curr, pip);
+				   curr, pip, HANDLE_DEATH_PENDING);
+	}
+}
+
+static void futex_cleanup(struct task_struct *tsk)
+{
+	if (unlikely(tsk->robust_list)) {
+		exit_robust_list(tsk);
+		tsk->robust_list = NULL;
+	}
+
+#ifdef CONFIG_COMPAT
+	if (unlikely(tsk->compat_robust_list)) {
+		compat_exit_robust_list(tsk);
+		tsk->compat_robust_list = NULL;
+	}
+#endif
+
+	if (unlikely(!list_empty(&tsk->pi_state_list)))
+		exit_pi_state_list(tsk);
+}
+
+/**
+ * futex_exit_recursive - Set the tasks futex state to FUTEX_STATE_DEAD
+ * @tsk:	task to set the state on
+ *
+ * Set the futex exit state of the task lockless. The futex waiter code
+ * observes that state when a task is exiting and loops until the task has
+ * actually finished the futex cleanup. The worst case for this is that the
+ * waiter runs through the wait loop until the state becomes visible.
+ *
+ * This is called from the recursive fault handling path in do_exit().
+ *
+ * This is best effort. Either the futex exit code has run already or
+ * not. If the OWNER_DIED bit has been set on the futex then the waiter can
+ * take it over. If not, the problem is pushed back to user space. If the
+ * futex exit code did not run yet, then an already queued waiter might
+ * block forever, but there is nothing which can be done about that.
+ */
+void futex_exit_recursive(struct task_struct *tsk)
+{
+	/* If the state is FUTEX_STATE_EXITING then futex_exit_mutex is held */
+	if (tsk->futex_state == FUTEX_STATE_EXITING)
+		mutex_unlock(&tsk->futex_exit_mutex);
+	tsk->futex_state = FUTEX_STATE_DEAD;
+}
+
+static void futex_cleanup_begin(struct task_struct *tsk)
+{
+	/*
+	 * Prevent various race issues against a concurrent incoming waiter
+	 * including live locks by forcing the waiter to block on
+	 * tsk->futex_exit_mutex when it observes FUTEX_STATE_EXITING in
+	 * attach_to_pi_owner().
+	 */
+	mutex_lock(&tsk->futex_exit_mutex);
+
+	/*
+	 * Switch the state to FUTEX_STATE_EXITING under tsk->pi_lock.
+	 *
+	 * This ensures that all subsequent checks of tsk->futex_state in
+	 * attach_to_pi_owner() must observe FUTEX_STATE_EXITING with
+	 * tsk->pi_lock held.
+	 *
+	 * It guarantees also that a pi_state which was queued right before
+	 * the state change under tsk->pi_lock by a concurrent waiter must
+	 * be observed in exit_pi_state_list().
+	 */
+	raw_spin_lock_irq(&tsk->pi_lock);
+	tsk->futex_state = FUTEX_STATE_EXITING;
+	raw_spin_unlock_irq(&tsk->pi_lock);
+}
+
+static void futex_cleanup_end(struct task_struct *tsk, int state)
+{
+	/*
+	 * Lockless store. The only side effect is that an observer might
+	 * take another loop until it becomes visible.
+	 */
+	tsk->futex_state = state;
+	/*
+	 * Drop the exit protection. This unblocks waiters which observed
+	 * FUTEX_STATE_EXITING to reevaluate the state.
+	 */
+	mutex_unlock(&tsk->futex_exit_mutex);
+}
+
+void futex_exec_release(struct task_struct *tsk)
+{
+	/*
+	 * The state handling is done for consistency, but in the case of
+	 * exec() there is no way to prevent futher damage as the PID stays
+	 * the same. But for the unlikely and arguably buggy case that a
+	 * futex is held on exec(), this provides at least as much state
+	 * consistency protection which is possible.
+	 */
+	futex_cleanup_begin(tsk);
+	futex_cleanup(tsk);
+	/*
+	 * Reset the state to FUTEX_STATE_OK. The task is alive and about
+	 * exec a new binary.
+	 */
+	futex_cleanup_end(tsk, FUTEX_STATE_OK);
+}
+
+void futex_exit_release(struct task_struct *tsk)
+{
+	futex_cleanup_begin(tsk);
+	futex_cleanup(tsk);
+	futex_cleanup_end(tsk, FUTEX_STATE_DEAD);
 }
 
 long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
@@ -3737,7 +3974,7 @@ static void __user *futex_uaddr(struct r
  *
  * We silently return on any sign of list-walking problem.
  */
-void compat_exit_robust_list(struct task_struct *curr)
+static void compat_exit_robust_list(struct task_struct *curr)
 {
 	struct compat_robust_list_head __user *head = curr->compat_robust_list;
 	struct robust_list __user *entry, *next_entry, *pending;
@@ -3784,7 +4021,8 @@ void compat_exit_robust_list(struct task
 		if (entry != pending) {
 			void __user *uaddr = futex_uaddr(entry, futex_offset);
 
-			if (handle_futex_death(uaddr, curr, pi))
+			if (handle_futex_death(uaddr, curr, pi,
+					       HANDLE_DEATH_LIST))
 				return;
 		}
 		if (rc)
@@ -3803,7 +4041,7 @@ void compat_exit_robust_list(struct task
 	if (pending) {
 		void __user *uaddr = futex_uaddr(pending, futex_offset);
 
-		handle_futex_death(uaddr, curr, pip);
+		handle_futex_death(uaddr, curr, pip, HANDLE_DEATH_PENDING);
 	}
 }
 
diff -druNp --no-dereference linux-libre-5.4-gnu/Makefile linux-libre-5.4.1-gnu/Makefile
--- linux-libre-5.4-gnu/Makefile	2019-11-24 20:49:59.000000000 -0500
+++ linux-libre-5.4.1-gnu/Makefile	2019-11-29 06:28:56.000000000 -0500
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 VERSION = 5
 PATCHLEVEL = 4
-SUBLEVEL = 0
+SUBLEVEL = 1
 EXTRAVERSION = -gnu
 NAME = Kleptomaniac Octopus
 
diff -druNp --no-dereference linux-libre-5.4-gnu/sound/pci/hda/patch_hdmi.c linux-libre-5.4.1-gnu/sound/pci/hda/patch_hdmi.c
--- linux-libre-5.4-gnu/sound/pci/hda/patch_hdmi.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/sound/pci/hda/patch_hdmi.c	2019-11-29 04:10:32.000000000 -0500
@@ -3454,26 +3454,6 @@ static int nvhdmi_chmap_validate(struct
 	return 0;
 }
 
-/* map from pin NID to port; port is 0-based */
-/* for Nvidia: assume widget NID starting from 4, with step 1 (4, 5, 6, ...) */
-static int nvhdmi_pin2port(void *audio_ptr, int pin_nid)
-{
-	return pin_nid - 4;
-}
-
-/* reverse-map from port to pin NID: see above */
-static int nvhdmi_port2pin(struct hda_codec *codec, int port)
-{
-	return port + 4;
-}
-
-static const struct drm_audio_component_audio_ops nvhdmi_audio_ops = {
-	.pin2port = nvhdmi_pin2port,
-	.pin_eld_notify = generic_acomp_pin_eld_notify,
-	.master_bind = generic_acomp_master_bind,
-	.master_unbind = generic_acomp_master_unbind,
-};
-
 static int patch_nvhdmi(struct hda_codec *codec)
 {
 	struct hdmi_spec *spec;
@@ -3492,8 +3472,6 @@ static int patch_nvhdmi(struct hda_codec
 
 	codec->link_down_at_suspend = 1;
 
-	generic_acomp_init(codec, &nvhdmi_audio_ops, nvhdmi_port2pin);
-
 	return 0;
 }
 
diff -druNp --no-dereference linux-libre-5.4-gnu/sound/usb/mixer.c linux-libre-5.4.1-gnu/sound/usb/mixer.c
--- linux-libre-5.4-gnu/sound/usb/mixer.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/sound/usb/mixer.c	2019-11-29 04:10:32.000000000 -0500
@@ -2930,6 +2930,9 @@ static int snd_usb_mixer_controls_badd(s
 			continue;
 
 		iface = usb_ifnum_to_if(dev, intf);
+		if (!iface)
+			continue;
+
 		num = iface->num_altsetting;
 
 		if (num < 2)
diff -druNp --no-dereference linux-libre-5.4-gnu/sound/usb/mixer_scarlett_gen2.c linux-libre-5.4.1-gnu/sound/usb/mixer_scarlett_gen2.c
--- linux-libre-5.4-gnu/sound/usb/mixer_scarlett_gen2.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/sound/usb/mixer_scarlett_gen2.c	2019-11-29 04:10:32.000000000 -0500
@@ -261,34 +261,34 @@ static const struct scarlett2_device_inf
 	},
 
 	.ports = {
-		{
+		[SCARLETT2_PORT_TYPE_NONE] = {
 			.id = 0x000,
 			.num = { 1, 0, 8, 8, 8 },
 			.src_descr = "Off",
 			.src_num_offset = 0,
 		},
-		{
+		[SCARLETT2_PORT_TYPE_ANALOGUE] = {
 			.id = 0x080,
 			.num = { 4, 4, 4, 4, 4 },
 			.src_descr = "Analogue %d",
 			.src_num_offset = 1,
 			.dst_descr = "Analogue Output %02d Playback"
 		},
-		{
+		[SCARLETT2_PORT_TYPE_SPDIF] = {
 			.id = 0x180,
 			.num = { 2, 2, 2, 2, 2 },
 			.src_descr = "S/PDIF %d",
 			.src_num_offset = 1,
 			.dst_descr = "S/PDIF Output %d Playback"
 		},
-		{
+		[SCARLETT2_PORT_TYPE_MIX] = {
 			.id = 0x300,
 			.num = { 10, 18, 18, 18, 18 },
 			.src_descr = "Mix %c",
 			.src_num_offset = 65,
 			.dst_descr = "Mixer Input %02d Capture"
 		},
-		{
+		[SCARLETT2_PORT_TYPE_PCM] = {
 			.id = 0x600,
 			.num = { 6, 6, 6, 6, 6 },
 			.src_descr = "PCM %d",
@@ -317,44 +317,44 @@ static const struct scarlett2_device_inf
 	},
 
 	.ports = {
-		{
+		[SCARLETT2_PORT_TYPE_NONE] = {
 			.id = 0x000,
 			.num = { 1, 0, 8, 8, 4 },
 			.src_descr = "Off",
 			.src_num_offset = 0,
 		},
-		{
+		[SCARLETT2_PORT_TYPE_ANALOGUE] = {
 			.id = 0x080,
 			.num = { 8, 6, 6, 6, 6 },
 			.src_descr = "Analogue %d",
 			.src_num_offset = 1,
 			.dst_descr = "Analogue Output %02d Playback"
 		},
-		{
+		[SCARLETT2_PORT_TYPE_SPDIF] = {
+			.id = 0x180,
 			/* S/PDIF outputs aren't available at 192KHz
 			 * but are included in the USB mux I/O
 			 * assignment message anyway
 			 */
-			.id = 0x180,
 			.num = { 2, 2, 2, 2, 2 },
 			.src_descr = "S/PDIF %d",
 			.src_num_offset = 1,
 			.dst_descr = "S/PDIF Output %d Playback"
 		},
-		{
+		[SCARLETT2_PORT_TYPE_ADAT] = {
 			.id = 0x200,
 			.num = { 8, 0, 0, 0, 0 },
 			.src_descr = "ADAT %d",
 			.src_num_offset = 1,
 		},
-		{
+		[SCARLETT2_PORT_TYPE_MIX] = {
 			.id = 0x300,
 			.num = { 10, 18, 18, 18, 18 },
 			.src_descr = "Mix %c",
 			.src_num_offset = 65,
 			.dst_descr = "Mixer Input %02d Capture"
 		},
-		{
+		[SCARLETT2_PORT_TYPE_PCM] = {
 			.id = 0x600,
 			.num = { 20, 18, 18, 14, 10 },
 			.src_descr = "PCM %d",
@@ -387,20 +387,20 @@ static const struct scarlett2_device_inf
 	},
 
 	.ports = {
-		{
+		[SCARLETT2_PORT_TYPE_NONE] = {
 			.id = 0x000,
 			.num = { 1, 0, 8, 8, 6 },
 			.src_descr = "Off",
 			.src_num_offset = 0,
 		},
-		{
+		[SCARLETT2_PORT_TYPE_ANALOGUE] = {
 			.id = 0x080,
 			.num = { 8, 10, 10, 10, 10 },
 			.src_descr = "Analogue %d",
 			.src_num_offset = 1,
 			.dst_descr = "Analogue Output %02d Playback"
 		},
-		{
+		[SCARLETT2_PORT_TYPE_SPDIF] = {
 			/* S/PDIF outputs aren't available at 192KHz
 			 * but are included in the USB mux I/O
 			 * assignment message anyway
@@ -411,21 +411,21 @@ static const struct scarlett2_device_inf
 			.src_num_offset = 1,
 			.dst_descr = "S/PDIF Output %d Playback"
 		},
-		{
+		[SCARLETT2_PORT_TYPE_ADAT] = {
 			.id = 0x200,
 			.num = { 8, 8, 8, 4, 0 },
 			.src_descr = "ADAT %d",
 			.src_num_offset = 1,
 			.dst_descr = "ADAT Output %d Playback"
 		},
-		{
+		[SCARLETT2_PORT_TYPE_MIX] = {
 			.id = 0x300,
 			.num = { 10, 18, 18, 18, 18 },
 			.src_descr = "Mix %c",
 			.src_num_offset = 65,
 			.dst_descr = "Mixer Input %02d Capture"
 		},
-		{
+		[SCARLETT2_PORT_TYPE_PCM] = {
 			.id = 0x600,
 			.num = { 20, 18, 18, 14, 10 },
 			.src_descr = "PCM %d",
diff -druNp --no-dereference linux-libre-5.4-gnu/tools/arch/x86/tools/gen-insn-attr-x86.awk linux-libre-5.4.1-gnu/tools/arch/x86/tools/gen-insn-attr-x86.awk
--- linux-libre-5.4-gnu/tools/arch/x86/tools/gen-insn-attr-x86.awk	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/tools/arch/x86/tools/gen-insn-attr-x86.awk	2019-11-29 04:10:32.000000000 -0500
@@ -69,7 +69,7 @@ BEGIN {
 
 	lprefix1_expr = "\\((66|!F3)\\)"
 	lprefix2_expr = "\\(F3\\)"
-	lprefix3_expr = "\\((F2|!F3|66\\&F2)\\)"
+	lprefix3_expr = "\\((F2|!F3|66&F2)\\)"
 	lprefix_expr = "\\((66|F2|F3)\\)"
 	max_lprefix = 4
 
@@ -257,7 +257,7 @@ function convert_operands(count,opnd,
 	return add_flags(imm, mod)
 }
 
-/^[0-9a-f]+\:/ {
+/^[0-9a-f]+:/ {
 	if (NR == 1)
 		next
 	# get index
diff -druNp --no-dereference linux-libre-5.4-gnu/tools/testing/selftests/x86/mov_ss_trap.c linux-libre-5.4.1-gnu/tools/testing/selftests/x86/mov_ss_trap.c
--- linux-libre-5.4-gnu/tools/testing/selftests/x86/mov_ss_trap.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/tools/testing/selftests/x86/mov_ss_trap.c	2019-11-29 04:10:32.000000000 -0500
@@ -257,7 +257,8 @@ int main()
 			err(1, "sigaltstack");
 		sethandler(SIGSEGV, handle_and_longjmp, SA_RESETHAND | SA_ONSTACK);
 		nr = SYS_getpid;
-		asm volatile ("mov %[ss], %%ss; SYSENTER" : "+a" (nr)
+		/* Clear EBP first to make sure we segfault cleanly. */
+		asm volatile ("xorl %%ebp, %%ebp; mov %[ss], %%ss; SYSENTER" : "+a" (nr)
 			      : [ss] "m" (ss) : "flags", "rcx"
 #ifdef __x86_64__
 				, "r11"
diff -druNp --no-dereference linux-libre-5.4-gnu/tools/testing/selftests/x86/sigreturn.c linux-libre-5.4.1-gnu/tools/testing/selftests/x86/sigreturn.c
--- linux-libre-5.4-gnu/tools/testing/selftests/x86/sigreturn.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/tools/testing/selftests/x86/sigreturn.c	2019-11-29 04:10:32.000000000 -0500
@@ -451,6 +451,19 @@ static void sigusr1(int sig, siginfo_t *
 	ctx->uc_mcontext.gregs[REG_SP] = (unsigned long)0x8badf00d5aadc0deULL;
 	ctx->uc_mcontext.gregs[REG_CX] = 0;
 
+#ifdef __i386__
+	/*
+	 * Make sure the kernel doesn't inadvertently use DS or ES-relative
+	 * accesses in a region where user DS or ES is loaded.
+	 *
+	 * Skip this for 64-bit builds because long mode doesn't care about
+	 * DS and ES and skipping it increases test coverage a little bit,
+	 * since 64-bit kernels can still run the 32-bit build.
+	 */
+	ctx->uc_mcontext.gregs[REG_DS] = 0;
+	ctx->uc_mcontext.gregs[REG_ES] = 0;
+#endif
+
 	memcpy(&requested_regs, &ctx->uc_mcontext.gregs, sizeof(gregset_t));
 	requested_regs[REG_CX] = *ssptr(ctx);	/* The asm code does this. */
 
diff -druNp --no-dereference linux-libre-5.4-gnu/tools/usb/usbip/libsrc/usbip_host_common.c linux-libre-5.4.1-gnu/tools/usb/usbip/libsrc/usbip_host_common.c
--- linux-libre-5.4-gnu/tools/usb/usbip/libsrc/usbip_host_common.c	2019-11-24 19:32:01.000000000 -0500
+++ linux-libre-5.4.1-gnu/tools/usb/usbip/libsrc/usbip_host_common.c	2019-11-29 04:10:32.000000000 -0500
@@ -57,7 +57,7 @@ static int32_t read_attr_usbip_status(st
 	}
 
 	value = atoi(status);
-
+	close(fd);
 	return value;
 }
 
