arm64 fixes:

- Allow EFI stub to use strnlen(), which is required by recent libfdt
 
 - Avoid smp_processor_id() in preempt context during unwinding
 
 - Avoid false Kasan warnings during unwinding
 
 - Ensure early devices are picked up by the IOMMU DMA ops
 
 - Avoid rebuilding the kernel for the 'install' target
 
 - Run fixup handlers for alignment faults on userspace access
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "Here are some more arm64 fixes for 4.5.  This has mostly come from
  Yang Shi, who saw some issues under -rt that also affect mainline.
  The rest of it is pretty small, but still worth having.

  We've got an old issue outstanding with valid_user_regs which will
  likely wait until 4.6 (since it would really benefit from some time in
  -next) and another issue with kasan and idle which should be fixed
  next week.

  Apart from that, pretty quiet here (and still no sign of the THP issue
  reported on s390...)

  Summary:

   - Allow EFI stub to use strnlen(), which is required by recent libfdt

   - Avoid smp_processor_id() in preempt context during unwinding

   - Avoid false Kasan warnings during unwinding

   - Ensure early devices are picked up by the IOMMU DMA ops

   - Avoid rebuilding the kernel for the 'install' target

   - Run fixup handlers for alignment faults on userspace access"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: mm: allow the kernel to handle alignment faults on user accesses
  arm64: kbuild: make "make install" not depend on vmlinux
  arm64: dma-mapping: fix handling of devices registered before arch_initcall
  arm64/efi: Make strnlen() available to the EFI namespace
  arm/arm64: crypto: assure that ECB modes don't require an IV
  arm64: make irq_stack_ptr more robust
  arm64: debug: re-enable irqs before sending breakpoint SIGTRAP
  arm64: disable kasan when accessing frame->fp in unwind_frame

arch/arm/crypto/aes-ce-glue.c

@@ -364,7 +364,7 @@ static struct crypto_alg aes_algs[] = { {
 	.cra_blkcipher = {
 		.min_keysize	= AES_MIN_KEY_SIZE,
 		.max_keysize	= AES_MAX_KEY_SIZE,
-		.ivsize		= AES_BLOCK_SIZE,
+		.ivsize		= 0,
 		.setkey		= ce_aes_setkey,
 		.encrypt	= ecb_encrypt,
 		.decrypt	= ecb_decrypt,
@@ -441,7 +441,7 @@ static struct crypto_alg aes_algs[] = { {
 	.cra_ablkcipher = {
 		.min_keysize	= AES_MIN_KEY_SIZE,
 		.max_keysize	= AES_MAX_KEY_SIZE,
-		.ivsize		= AES_BLOCK_SIZE,
+		.ivsize		= 0,
 		.setkey		= ablk_set_key,
 		.encrypt	= ablk_encrypt,
 		.decrypt	= ablk_decrypt,

arch/arm64/Makefile

@@ -88,7 +88,7 @@ Image: vmlinux
 Image.%: vmlinux
 	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
 
-zinstall install: vmlinux
+zinstall install:
 	$(Q)$(MAKE) $(build)=$(boot) $@
 
 %.dtb: scripts

arch/arm64/boot/Makefile

@@ -34,10 +34,10 @@ $(obj)/Image.lzma: $(obj)/Image FORCE
 $(obj)/Image.lzo: $(obj)/Image FORCE
 	$(call if_changed,lzo)
 
-install: $(obj)/Image
+install:
 	$(CONFIG_SHELL) $(srctree)/$(src)/install.sh $(KERNELRELEASE) \
 	$(obj)/Image System.map "$(INSTALL_PATH)"
 
-zinstall: $(obj)/Image.gz
+zinstall:
 	$(CONFIG_SHELL) $(srctree)/$(src)/install.sh $(KERNELRELEASE) \
 	$(obj)/Image.gz System.map "$(INSTALL_PATH)"

arch/arm64/boot/install.sh

@@ -20,6 +20,20 @@
 #   $4 - default install path (blank if root directory)
 #
 
+verify () {
+	if [ ! -f "$1" ]; then
+		echo ""                                                   1>&2
+		echo " *** Missing file: $1"                              1>&2
+		echo ' *** You need to run "make" before "make install".' 1>&2
+		echo ""                                                   1>&2
+		exit 1
+	fi
+}
+
+# Make sure the files actually exist
+verify "$2"
+verify "$3"
+
 # User may have a custom install script
 if [ -x ~/bin/${INSTALLKERNEL} ]; then exec ~/bin/${INSTALLKERNEL} "$@"; fi
 if [ -x /sbin/${INSTALLKERNEL} ]; then exec /sbin/${INSTALLKERNEL} "$@"; fi

arch/arm64/crypto/aes-glue.c

@@ -294,7 +294,7 @@ static struct crypto_alg aes_algs[] = { {
 	.cra_blkcipher = {
 		.min_keysize	= AES_MIN_KEY_SIZE,
 		.max_keysize	= AES_MAX_KEY_SIZE,
-		.ivsize		= AES_BLOCK_SIZE,
+		.ivsize		= 0,
 		.setkey		= aes_setkey,
 		.encrypt	= ecb_encrypt,
 		.decrypt	= ecb_decrypt,
@@ -371,7 +371,7 @@ static struct crypto_alg aes_algs[] = { {
 	.cra_ablkcipher = {
 		.min_keysize	= AES_MIN_KEY_SIZE,
 		.max_keysize	= AES_MAX_KEY_SIZE,
-		.ivsize		= AES_BLOCK_SIZE,
+		.ivsize		= 0,
 		.setkey		= ablk_set_key,
 		.encrypt	= ablk_encrypt,
 		.decrypt	= ablk_decrypt,

arch/arm64/kernel/debug-monitors.c

@@ -226,11 +226,28 @@ static int call_step_hook(struct pt_regs *regs, unsigned int esr)
 	return retval;
 }
 
+static void send_user_sigtrap(int si_code)
+{
+	struct pt_regs *regs = current_pt_regs();
+	siginfo_t info = {
+		.si_signo	= SIGTRAP,
+		.si_errno	= 0,
+		.si_code	= si_code,
+		.si_addr	= (void __user *)instruction_pointer(regs),
+	};
+
+	if (WARN_ON(!user_mode(regs)))
+		return;
+
+	if (interrupts_enabled(regs))
+		local_irq_enable();
+
+	force_sig_info(SIGTRAP, &info, current);
+}
+
 static int single_step_handler(unsigned long addr, unsigned int esr,
 			       struct pt_regs *regs)
 {
-	siginfo_t info;
-
 	/*
 	 * If we are stepping a pending breakpoint, call the hw_breakpoint
 	 * handler first.
@@ -239,11 +256,7 @@ static int single_step_handler(unsigned long addr, unsigned int esr,
 		return 0;
 
 	if (user_mode(regs)) {
-		info.si_signo = SIGTRAP;
-		info.si_errno = 0;
-		info.si_code  = TRAP_HWBKPT;
-		info.si_addr  = (void __user *)instruction_pointer(regs);
-		force_sig_info(SIGTRAP, &info, current);
+		send_user_sigtrap(TRAP_HWBKPT);
 
 		/*
 		 * ptrace will disable single step unless explicitly
@@ -307,17 +320,8 @@ static int call_break_hook(struct pt_regs *regs, unsigned int esr)
 static int brk_handler(unsigned long addr, unsigned int esr,
 		       struct pt_regs *regs)
 {
-	siginfo_t info;
-
 	if (user_mode(regs)) {
-		info = (siginfo_t) {
-			.si_signo = SIGTRAP,
-			.si_errno = 0,
-			.si_code  = TRAP_BRKPT,
-			.si_addr  = (void __user *)instruction_pointer(regs),
-		};
-
-		force_sig_info(SIGTRAP, &info, current);
+		send_user_sigtrap(TRAP_BRKPT);
 	} else if (call_break_hook(regs, esr) != DBG_HOOK_HANDLED) {
 		pr_warning("Unexpected kernel BRK exception at EL1\n");
 		return -EFAULT;
@@ -328,7 +332,6 @@ static int brk_handler(unsigned long addr, unsigned int esr,
 
 int aarch32_break_handler(struct pt_regs *regs)
 {
-	siginfo_t info;
 	u32 arm_instr;
 	u16 thumb_instr;
 	bool bp = false;
@@ -359,14 +362,7 @@ int aarch32_break_handler(struct pt_regs *regs)
 	if (!bp)
 		return -EFAULT;
 
-	info = (siginfo_t) {
-		.si_signo = SIGTRAP,
-		.si_errno = 0,
-		.si_code  = TRAP_BRKPT,
-		.si_addr  = pc,
-	};
-
-	force_sig_info(SIGTRAP, &info, current);
+	send_user_sigtrap(TRAP_BRKPT);
 	return 0;
 }
 

arch/arm64/kernel/image.h

@@ -89,6 +89,7 @@ __efistub_memcpy		= KALLSYMS_HIDE(__pi_memcpy);
 __efistub_memmove		= KALLSYMS_HIDE(__pi_memmove);
 __efistub_memset		= KALLSYMS_HIDE(__pi_memset);
 __efistub_strlen		= KALLSYMS_HIDE(__pi_strlen);
+__efistub_strnlen		= KALLSYMS_HIDE(__pi_strnlen);
 __efistub_strcmp		= KALLSYMS_HIDE(__pi_strcmp);
 __efistub_strncmp		= KALLSYMS_HIDE(__pi_strncmp);
 __efistub___flush_dcache_area	= KALLSYMS_HIDE(__pi___flush_dcache_area);

arch/arm64/kernel/stacktrace.c

@@ -44,14 +44,13 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
 	unsigned long irq_stack_ptr;
 
 	/*
-	 * Use raw_smp_processor_id() to avoid false-positives from
-	 * CONFIG_DEBUG_PREEMPT. get_wchan() calls unwind_frame() on sleeping
-	 * task stacks, we can be pre-empted in this case, so
-	 * {raw_,}smp_processor_id() may give us the wrong value. Sleeping
-	 * tasks can't ever be on an interrupt stack, so regardless of cpu,
-	 * the checks will always fail.
+	 * Switching between stacks is valid when tracing current and in
+	 * non-preemptible context.
 	 */
-	irq_stack_ptr = IRQ_STACK_PTR(raw_smp_processor_id());
+	if (tsk == current && !preemptible())
+		irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id());
+	else
+		irq_stack_ptr = 0;
 
 	low  = frame->sp;
 	/* irq stacks are not THREAD_SIZE aligned */
@@ -64,8 +63,8 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
 		return -EINVAL;
 
 	frame->sp = fp + 0x10;
-	frame->fp = *(unsigned long *)(fp);
-	frame->pc = *(unsigned long *)(fp + 8);
+	frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp));
+	frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8));
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	if (tsk && tsk->ret_stack &&

arch/arm64/kernel/traps.c

@@ -146,9 +146,18 @@ static void dump_instr(const char *lvl, struct pt_regs *regs)
 static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
 {
 	struct stackframe frame;
-	unsigned long irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id());
+	unsigned long irq_stack_ptr;
 	int skip;
 
+	/*
+	 * Switching between stacks is valid when tracing current and in
+	 * non-preemptible context.
+	 */
+	if (tsk == current && !preemptible())
+		irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id());
+	else
+		irq_stack_ptr = 0;
+
 	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
 
 	if (!tsk)

arch/arm64/lib/strnlen.S

@@ -168,4 +168,4 @@ CPU_LE( lsr	tmp2, tmp2, tmp4 )	/* Shift (tmp1 & 63).  */
 .Lhit_limit:
 	mov	len, limit
 	ret
-ENDPROC(strnlen)
+ENDPIPROC(strnlen)

arch/arm64/mm/dma-mapping.c

@@ -933,6 +933,10 @@ static int __init __iommu_dma_init(void)
 		ret = register_iommu_dma_ops_notifier(&platform_bus_type);
 	if (!ret)
 		ret = register_iommu_dma_ops_notifier(&amba_bustype);
+
+	/* handle devices queued before this arch_initcall */
+	if (!ret)
+		__iommu_attach_notifier(NULL, BUS_NOTIFY_ADD_DEVICE, NULL);
 	return ret;
 }
 arch_initcall(__iommu_dma_init);

arch/arm64/mm/fault.c

@@ -371,6 +371,13 @@ static int __kprobes do_translation_fault(unsigned long addr,
 	return 0;
 }
 
+static int do_alignment_fault(unsigned long addr, unsigned int esr,
+			      struct pt_regs *regs)
+{
+	do_bad_area(addr, esr, regs);
+	return 0;
+}
+
 /*
  * This abort handler always returns "fault".
  */
@@ -418,7 +425,7 @@ static struct fault_info {
 	{ do_bad,		SIGBUS,  0,		"synchronous parity error (translation table walk)" },
 	{ do_bad,		SIGBUS,  0,		"synchronous parity error (translation table walk)" },
 	{ do_bad,		SIGBUS,  0,		"unknown 32"			},
-	{ do_bad,		SIGBUS,  BUS_ADRALN,	"alignment fault"		},
+	{ do_alignment_fault,	SIGBUS,  BUS_ADRALN,	"alignment fault"		},
 	{ do_bad,		SIGBUS,  0,		"unknown 34"			},
 	{ do_bad,		SIGBUS,  0,		"unknown 35"			},
 	{ do_bad,		SIGBUS,  0,		"unknown 36"			},