Merge branch 'arm64/exception-stack' of git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux into for-next/core

* 'arm64/exception-stack' of git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux:
  arm64: unwind: remove sp from struct stackframe
  arm64: unwind: reference pt_regs via embedded stack frame
  arm64: unwind: disregard frame.sp when validating frame pointer
  arm64: unwind: avoid percpu indirection for irq stack
  arm64: move non-entry code out of .entry.text
  arm64: consistently use bl for C exception entry
  arm64: Add ASM_BUG()

7 files changed, 85 insertions, 61 deletions

diff --git a/arch/arm64/include/asm/asm-bug.h b/arch/arm64/include/asm/asm-bug.h
new file mode 100644
index 000000000000..636e755bcdca
--- /dev/null
+++ b/arch/arm64/include/asm/asm-bug.h
@@ -0,0 +1,54 @@
+#ifndef __ASM_ASM_BUG_H
+/*
+ * Copyright (C) 2017  ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#define __ASM_ASM_BUG_H
+
+#include <asm/brk-imm.h>
+
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+#define _BUGVERBOSE_LOCATION(file, line) __BUGVERBOSE_LOCATION(file, line)
+#define __BUGVERBOSE_LOCATION(file, line)			\
+		.pushsection .rodata.str,"aMS",@progbits,1;	\
+	2:	.string file;					\
+		.popsection;					\
+								\
+		.long 2b - 0b;					\
+		.short line;
+#else
+#define _BUGVERBOSE_LOCATION(file, line)
+#endif
+
+#ifdef CONFIG_GENERIC_BUG
+
+#define __BUG_ENTRY(flags) 				\
+		.pushsection __bug_table,"aw";		\
+		.align 2;				\
+	0:	.long 1f - 0b;				\
+_BUGVERBOSE_LOCATION(__FILE__, __LINE__)		\
+		.short flags; 				\
+		.popsection;				\
+	1:
+#else
+#define __BUG_ENTRY(flags)
+#endif
+
+#define ASM_BUG_FLAGS(flags)				\
+	__BUG_ENTRY(flags)				\
+	brk	BUG_BRK_IMM
+
+#define ASM_BUG()	ASM_BUG_FLAGS(0)
+
+#endif /* __ASM_ASM_BUG_H */
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 5d8903c45031..1ef56837cc6f 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -409,6 +409,17 @@ alternative_endif
 	.size	__pi_##x, . - x;	\
 	ENDPROC(x)
 
+/*
+ * Annotate a function as being unsuitable for kprobes.
+ */
+#ifdef CONFIG_KPROBES
+#define NOKPROBE(x)				\
+	.pushsection "_kprobe_blacklist", "aw";	\
+	.quad	x;				\
+	.popsection;
+#else
+#define NOKPROBE(x)
+#endif
 	/*
 	 * Emit a 64-bit absolute little endian symbol reference in a way that
 	 * ensures that it will be resolved at build time, even when building a
diff --git a/arch/arm64/include/asm/bug.h b/arch/arm64/include/asm/bug.h
index a02a57186f56..d7dc43752705 100644
--- a/arch/arm64/include/asm/bug.h
+++ b/arch/arm64/include/asm/bug.h
@@ -18,41 +18,12 @@
 #ifndef _ARCH_ARM64_ASM_BUG_H
 #define _ARCH_ARM64_ASM_BUG_H
 
-#include <asm/brk-imm.h>
+#include <linux/stringify.h>
 
-#ifdef CONFIG_DEBUG_BUGVERBOSE
-#define _BUGVERBOSE_LOCATION(file, line) __BUGVERBOSE_LOCATION(file, line)
-#define __BUGVERBOSE_LOCATION(file, line)				\
-		".pushsection .rodata.str,\"aMS\",@progbits,1\n"	\
-	"2:	.string \"" file "\"\n\t"				\
-		".popsection\n\t"					\
-									\
-		".long 2b - 0b\n\t"					\
-		".short " #line "\n\t"
-#else
-#define _BUGVERBOSE_LOCATION(file, line)
-#endif
-
-#ifdef CONFIG_GENERIC_BUG
-
-#define __BUG_ENTRY(flags) 				\
-		".pushsection __bug_table,\"aw\"\n\t"	\
-		".align 2\n\t"				\
-	"0:	.long 1f - 0b\n\t"			\
-_BUGVERBOSE_LOCATION(__FILE__, __LINE__)		\
-		".short " #flags "\n\t"			\
-		".popsection\n"				\
-	"1:	"
-#else
-#define __BUG_ENTRY(flags) ""
-#endif
+#include <asm/asm-bug.h>
 
 #define __BUG_FLAGS(flags)				\
-	asm volatile (					\
-		__BUG_ENTRY(flags)			\
-		"brk %[imm]" :: [imm] "i" (BUG_BRK_IMM)	\
-	);
-
+	asm volatile (__stringify(ASM_BUG_FLAGS(flags)));
 
 #define BUG() do {					\
 	__BUG_FLAGS(0);					\
diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h
index b77197d941fc..8ba89c4ca183 100644
--- a/arch/arm64/include/asm/irq.h
+++ b/arch/arm64/include/asm/irq.h
@@ -7,6 +7,7 @@
 #ifndef __ASSEMBLER__
 
 #include <linux/percpu.h>
+#include <linux/sched/task_stack.h>
 
 #include <asm-generic/irq.h>
 #include <asm/thread_info.h>
@@ -15,31 +16,6 @@ struct pt_regs;
 
 DECLARE_PER_CPU(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack);
 
-/*
- * The highest address on the stack, and the first to be used. Used to
- * find the dummy-stack frame put down by el?_irq() in entry.S, which
- * is structured as follows:
- *
- *       ------------
- *       |          |  <- irq_stack_ptr
- *   top ------------
- *       |   x19    | <- irq_stack_ptr - 0x08
- *       ------------
- *       |   x29    | <- irq_stack_ptr - 0x10
- *       ------------
- *
- * where x19 holds a copy of the task stack pointer where the struct pt_regs
- * from kernel_entry can be found.
- *
- */
-#define IRQ_STACK_PTR(cpu) ((unsigned long)per_cpu(irq_stack, cpu) + IRQ_STACK_START_SP)
-
-/*
- * The offset from irq_stack_ptr where entry.S will store the original
- * stack pointer. Used by unwind_frame() and dump_backtrace().
- */
-#define IRQ_STACK_TO_TASK_STACK(ptr) (*((unsigned long *)((ptr) - 0x08)))
-
 extern void set_handle_irq(void (*handle_irq)(struct pt_regs *));
 
 static inline int nr_legacy_irqs(void)
@@ -47,14 +23,21 @@ static inline int nr_legacy_irqs(void)
 	return 0;
 }
 
-static inline bool on_irq_stack(unsigned long sp, int cpu)
+static inline bool on_irq_stack(unsigned long sp)
 {
-	/* variable names the same as kernel/stacktrace.c */
-	unsigned long low = (unsigned long)per_cpu(irq_stack, cpu);
+	unsigned long low = (unsigned long)raw_cpu_ptr(irq_stack);
 	unsigned long high = low + IRQ_STACK_START_SP;
 
 	return (low <= sp && sp <= high);
 }
 
+static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp)
+{
+	unsigned long low = (unsigned long)task_stack_page(tsk);
+	unsigned long high = low + THREAD_SIZE;
+
+	return (low <= sp && sp < high);
+}
+
 #endif /* !__ASSEMBLER__ */
 #endif
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index 4f64373b84fd..6069d66e0bc2 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -137,6 +137,7 @@ struct pt_regs {
 
 	u64 orig_addr_limit;
 	u64 unused;	// maintain 16 byte alignment
+	u64 stackframe[2];
 };
 
 static inline bool in_syscall(struct pt_regs const *regs)
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 5b6eafccc5d8..3bebab378c72 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -20,7 +20,6 @@ struct task_struct;
 
 struct stackframe {
 	unsigned long fp;
-	unsigned long sp;
 	unsigned long pc;
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	unsigned int graph;
diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h
index 02e9035b0685..41361684580d 100644
--- a/arch/arm64/include/asm/traps.h
+++ b/arch/arm64/include/asm/traps.h
@@ -60,4 +60,9 @@ static inline int in_exception_text(unsigned long ptr)
 	return in ? : __in_irqentry_text(ptr);
 }
 
+static inline int in_entry_text(unsigned long ptr)
+{
+	return ptr >= (unsigned long)&__entry_text_start &&
+	       ptr < (unsigned long)&__entry_text_end;
+}
 #endif