[PATCH] powerpc: Print instruction when logging unhandled exceptions
From: Anton Blanchard <hidden>
Date: 2014-09-25 05:05:46
It is often useful to see the instruction that caused an unhandled exception. Signed-off-by: Anton Blanchard <redacted> --- arch/powerpc/kernel/traps.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 0dc43f9..27e30c8 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c@@ -36,10 +36,10 @@ #include <linux/debugfs.h> #include <linux/ratelimit.h> #include <linux/context_tracking.h> +#include <linux/uaccess.h> #include <asm/emulated_ops.h> #include <asm/pgtable.h> -#include <asm/uaccess.h> #include <asm/io.h> #include <asm/machdep.h> #include <asm/rtas.h>
@@ -242,9 +242,9 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr) { siginfo_t info; const char fmt32[] = KERN_INFO "%s[%d]: unhandled signal %d " \ - "at %08lx nip %08lx lr %08lx code %x\n"; + "at %08lx nip %08lx lr %08lx code %x insn %08x\n"; const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \ - "at %016lx nip %016lx lr %016lx code %x\n"; + "at %016lx nip %016lx lr %016lx code %x insn %08x\n"; if (!user_mode(regs)) { die("Exception in kernel mode", regs, signr);
@@ -252,9 +252,18 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr) } if (show_unhandled_signals && unhandled_signal(current, signr)) { + u32 __user *nia = (u32 __user *)regs->nip; + u32 insn = 0; + + pagefault_disable(); + if (!access_ok(VERIFY_READ, nia, sizeof(*nia)) || + __get_user_inatomic(insn, nia)) + insn = 0xffffffffUL; + pagefault_enable(); + printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, current->comm, current->pid, signr, - addr, regs->nip, regs->link, code); + addr, regs->nip, regs->link, code, insn); } if (arch_irqs_disabled() && !arch_irq_disabled_regs(regs))
--
1.9.1