Re: [PATCH] powerpc: fix kernel log of oops/panic instruction dump
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2012-01-06 22:50:17
On Fri, 2012-01-06 at 14:34 -0800, Ira W. Snyder wrote:
A kernel oops/panic prints an instruction dump showing several instructions before and after the instruction which caused the oops/panic. The code intended that the faulting instruction be enclosed in angle brackets, however a bug caused the faulting instruction to be interpreted by printk() as the message log level. To fix this, the KERN_CONT log level is added before the actualy text of the printed message.
Nice one, thanks. Cheers, Ben.
quoted hunk ↗ jump to hunk
=== Before the patch === [ 1081.587266] Instruction dump: [ 1081.590236] 7c000110 7c0000f8 5400077c 552907f6 7d290378 992b0003 4e800020 38000001 [ 1081.598034] 3d20c03a 9009a114 7c0004ac 39200000 [ 1081.602500] 4e800020 3803ffd0 2b800009 <4>[ 1081.587266] Instruction dump: <4>[ 1081.590236] 7c000110 7c0000f8 5400077c 552907f6 7d290378 992b0003 4e800020 38000001 <4>[ 1081.598034] 3d20c03a 9009a114 7c0004ac 39200000 <98090000>[ 1081.602500] 4e800020 3803ffd0 2b800009 === After the patch === [ 51.385216] Instruction dump: [ 51.388186] 7c000110 7c0000f8 5400077c 552907f6 7d290378 992b0003 4e800020 38000001 [ 51.395986] 3d20c03a 9009a114 7c0004ac 39200000 <98090000> 4e800020 3803ffd0 2b800009 <4>[ 51.385216] Instruction dump: <4>[ 51.388186] 7c000110 7c0000f8 5400077c 552907f6 7d290378 992b0003 4e800020 38000001 <4>[ 51.395986] 3d20c03a 9009a114 7c0004ac 39200000 <98090000> 4e800020 3803ffd0 2b800009 Signed-off-by: Ira W. Snyder <redacted> Cc: Paul Mackerras <redacted> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: linuxppc-dev@lists.ozlabs.org --- In the above examples, the first block is what is shown on the serial console as the machine dies. The second block is the dump as captured by mtdoops. arch/powerpc/kernel/process.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-)diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 6457574..271f809 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c@@ -566,12 +566,12 @@ static void show_instructions(struct pt_regs *regs) */ if (!__kernel_text_address(pc) || __get_user(instr, (unsigned int __user *)pc)) { - printk("XXXXXXXX "); + printk(KERN_CONT "XXXXXXXX "); } else { if (regs->nip == pc) - printk("<%08x> ", instr); + printk(KERN_CONT "<%08x> ", instr); else - printk("%08x ", instr); + printk(KERN_CONT "%08x ", instr); } pc += sizeof(int);