From 86c418374223be3f328b5522545196db02c8ceda Mon Sep 17 00:00:00 2001 From: Chuck Ebbert Date: Tue, 13 Feb 2007 13:26:25 +0100 Subject: [PATCH] [PATCH] i386: add option to show more code in oops reports Sometimes developers need to see more object code in an oops report, e.g. when kernel may be corrupted at runtime. Add the "code_bytes" option for this. Signed-off-by: Chuck Ebbert Signed-off-by: Andi Kleen Cc: Andi Kleen Signed-off-by: Andrew Morton --- Documentation/kernel-parameters.txt | 5 +++++ arch/i386/kernel/traps.c | 20 ++++++++++++++++---- 2 files changed, 21 insertions(+), 4 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 733a736bc6c..22b19962a1a 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -364,6 +364,11 @@ and is between 256 and 4096 characters. It is defined in the file clocksource is not available, it defaults to PIT. Format: { pit | tsc | cyclone | pmtmr } + code_bytes [IA32] How many bytes of object code to print in an + oops report. + Range: 0 - 8192 + Default: 64 + disable_8254_timer enable_8254_timer [IA32/X86_64] Disable/Enable interrupt 0 timer routing diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index 4ec21037a36..af0d3f70a81 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -94,6 +94,7 @@ asmlinkage void spurious_interrupt_bug(void); asmlinkage void machine_check(void); int kstack_depth_to_print = 24; +static unsigned int code_bytes = 64; ATOMIC_NOTIFIER_HEAD(i386die_chain); int register_die_notifier(struct notifier_block *nb) @@ -325,7 +326,8 @@ void show_registers(struct pt_regs *regs) */ if (in_kernel) { u8 *eip; - int code_bytes = 64; + unsigned int code_prologue = code_bytes * 43 / 64; + unsigned int code_len = code_bytes; unsigned char c; printk("\n" KERN_EMERG "Stack: "); @@ -333,14 +335,14 @@ void show_registers(struct pt_regs *regs) printk(KERN_EMERG "Code: "); - eip = (u8 *)regs->eip - 43; + eip = (u8 *)regs->eip - code_prologue; if (eip < (u8 *)PAGE_OFFSET || probe_kernel_address(eip, c)) { /* try starting at EIP */ eip = (u8 *)regs->eip; - code_bytes = 32; + code_len = code_len - code_prologue + 1; } - for (i = 0; i < code_bytes; i++, eip++) { + for (i = 0; i < code_len; i++, eip++) { if (eip < (u8 *)PAGE_OFFSET || probe_kernel_address(eip, c)) { printk(" Bad EIP value."); @@ -1192,3 +1194,13 @@ static int __init kstack_setup(char *s) return 1; } __setup("kstack=", kstack_setup); + +static int __init code_bytes_setup(char *s) +{ + code_bytes = simple_strtoul(s, NULL, 0); + if (code_bytes > 8192) + code_bytes = 8192; + + return 1; +} +__setup("code_bytes=", code_bytes_setup); -- 2.41.1