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-rw-r--r--arch/arm/Kconfig4
-rw-r--r--arch/arm/include/asm/bug.h55
-rw-r--r--arch/arm/kernel/traps.c31
-rw-r--r--arch/arm/kernel/vmlinux.lds.S3
4 files changed, 73 insertions, 20 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 3269576dbfa8..1412da8ccf05 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -215,6 +215,10 @@ config ARM_PATCH_PHYS_VIRT_16BIT
to allow physical memory down to a theoretical minimum of 64K
boundaries.
+config GENERIC_BUG
+ def_bool y
+ depends on BUG
+
source "init/Kconfig"
source "kernel/Kconfig.freezer"
diff --git a/arch/arm/include/asm/bug.h b/arch/arm/include/asm/bug.h
index 4d88425a4169..9abe7a07d5ac 100644
--- a/arch/arm/include/asm/bug.h
+++ b/arch/arm/include/asm/bug.h
@@ -3,21 +3,58 @@
#ifdef CONFIG_BUG
-#ifdef CONFIG_DEBUG_BUGVERBOSE
-extern void __bug(const char *file, int line) __attribute__((noreturn));
-
-/* give file/line information */
-#define BUG() __bug(__FILE__, __LINE__)
+/*
+ * Use a suitable undefined instruction to use for ARM/Thumb2 bug handling.
+ * We need to be careful not to conflict with those used by other modules and
+ * the register_undef_hook() system.
+ */
+#ifdef CONFIG_THUMB2_KERNEL
+#define BUG_INSTR_VALUE 0xde02
+#define BUG_INSTR_TYPE ".hword "
#else
+#define BUG_INSTR_VALUE 0xe7f001f2
+#define BUG_INSTR_TYPE ".word "
+#endif
-/* this just causes an oops */
-#define BUG() do { *(int *)0 = 0; } while (1)
-#endif
+#define BUG() _BUG(__FILE__, __LINE__, BUG_INSTR_VALUE)
+#define _BUG(file, line, value) __BUG(file, line, value)
+
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+
+/*
+ * The extra indirection is to ensure that the __FILE__ string comes through
+ * OK. Many version of gcc do not support the asm %c parameter which would be
+ * preferable to this unpleasantness. We use mergeable string sections to
+ * avoid multiple copies of the string appearing in the kernel image.
+ */
+
+#define __BUG(__file, __line, __value) \
+do { \
+ BUILD_BUG_ON(sizeof(struct bug_entry) != 12); \
+ asm volatile("1:\t" BUG_INSTR_TYPE #__value "\n" \
+ ".pushsection .rodata.str, \"aMS\", %progbits, 1\n" \
+ "2:\t.asciz " #__file "\n" \
+ ".popsection\n" \
+ ".pushsection __bug_table,\"a\"\n" \
+ "3:\t.word 1b, 2b\n" \
+ "\t.hword " #__line ", 0\n" \
+ ".popsection"); \
+ unreachable(); \
+} while (0)
+
+#else /* not CONFIG_DEBUG_BUGVERBOSE */
+
+#define __BUG(__file, __line, __value) \
+do { \
+ asm volatile(BUG_INSTR_TYPE #__value); \
+ unreachable(); \
+} while (0)
+#endif /* CONFIG_DEBUG_BUGVERBOSE */
#define HAVE_ARCH_BUG
-#endif
+#endif /* CONFIG_BUG */
#include <asm-generic/bug.h>
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index bc9f9da782cb..74969248c375 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -21,6 +21,7 @@
#include <linux/kdebug.h>
#include <linux/module.h>
#include <linux/kexec.h>
+#include <linux/bug.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/sched.h>
@@ -270,6 +271,8 @@ void die(const char *str, struct pt_regs *regs, int err)
spin_lock_irq(&die_lock);
console_verbose();
bust_spinlocks(1);
+ if (!user_mode(regs))
+ report_bug(regs->ARM_pc, regs);
ret = __die(str, err, thread, regs);
if (regs && kexec_should_crash(thread->task))
@@ -301,6 +304,24 @@ void arm_notify_die(const char *str, struct pt_regs *regs,
}
}
+#ifdef CONFIG_GENERIC_BUG
+
+int is_valid_bugaddr(unsigned long pc)
+{
+#ifdef CONFIG_THUMB2_KERNEL
+ unsigned short bkpt;
+#else
+ unsigned long bkpt;
+#endif
+
+ if (probe_kernel_address((unsigned *)pc, bkpt))
+ return 0;
+
+ return bkpt == BUG_INSTR_VALUE;
+}
+
+#endif
+
static LIST_HEAD(undef_hook);
static DEFINE_SPINLOCK(undef_lock);
@@ -706,16 +727,6 @@ baddataabort(int code, unsigned long instr, struct pt_regs *regs)
arm_notify_die("unknown data abort code", regs, &info, instr, 0);
}
-void __attribute__((noreturn)) __bug(const char *file, int line)
-{
- printk(KERN_CRIT"kernel BUG at %s:%d!\n", file, line);
- *(int *)0 = 0;
-
- /* Avoid "noreturn function does return" */
- for (;;);
-}
-EXPORT_SYMBOL(__bug);
-
void __readwrite_bug(const char *fn)
{
printk("%s called, but not implemented\n", fn);
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index bf977f8514f6..7b2541efd9f8 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -21,7 +21,8 @@
#define ARM_CPU_KEEP(x)
#endif
-#if defined(CONFIG_SMP_ON_UP) && !defined(CONFIG_DEBUG_SPINLOCK)
+#if (defined(CONFIG_SMP_ON_UP) && !defined(CONFIG_DEBUG_SPINLOCK)) || \
+ defined(CONFIG_GENERIC_BUG)
#define ARM_EXIT_KEEP(x) x
#else
#define ARM_EXIT_KEEP(x)