diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index e7910f8b4fc..40db7dd1d92 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -416,8 +416,8 @@ and is between 256 and 4096 characters. It is defined in the file [SPARC64] tick [X86-64] hpet,tsc - code_bytes [IA32] How many bytes of object code to print in an - oops report. + code_bytes [IA32/X86_64] How many bytes of object code to print + in an oops report. Range: 0 - 8192 Default: 64 diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c index 304ca6b4a1c..0bba7924604 100644 --- a/arch/x86/kernel/traps_64.c +++ b/arch/x86/kernel/traps_64.c @@ -74,6 +74,8 @@ asmlinkage void alignment_check(void); asmlinkage void machine_check(void); asmlinkage void spurious_interrupt_bug(void); +static unsigned int code_bytes = 64; + static inline void conditional_sti(struct pt_regs *regs) { if (regs->flags & X86_EFLAGS_IF) @@ -459,12 +461,15 @@ EXPORT_SYMBOL(dump_stack); void show_registers(struct pt_regs *regs) { int i; - int in_kernel = !user_mode(regs); unsigned long sp; const int cpu = smp_processor_id(); struct task_struct *cur = cpu_pda(cpu)->pcurrent; + u8 *ip; + unsigned int code_prologue = code_bytes * 43 / 64; + unsigned int code_len = code_bytes; sp = regs->sp; + ip = (u8 *) regs->ip - code_prologue; printk("CPU %d ", cpu); __show_regs(regs); printk("Process %s (pid: %d, threadinfo %p, task %p)\n", @@ -474,22 +479,28 @@ void show_registers(struct pt_regs *regs) * When in-kernel, we also print out the stack and code at the * time of the fault.. */ - if (in_kernel) { + if (!user_mode(regs)) { + unsigned char c; printk("Stack: "); _show_stack(NULL, regs, (unsigned long *)sp, regs->bp); + printk("\n"); - printk("\nCode: "); - if (regs->ip < PAGE_OFFSET) - goto bad; - - for (i=0; i<20; i++) { - unsigned char c; - if (__get_user(c, &((unsigned char*)regs->ip)[i])) { -bad: + printk(KERN_EMERG "Code: "); + if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) { + /* try starting at RIP */ + ip = (u8 *) regs->ip; + code_len = code_len - code_prologue + 1; + } + for (i = 0; i < code_len; i++, ip++) { + if (ip < (u8 *)PAGE_OFFSET || + probe_kernel_address(ip, c)) { printk(" Bad RIP value."); break; } - printk("%02x ", c); + if (ip == (u8 *)regs->ip) + printk("<%02x> ", c); + else + printk("%02x ", c); } } printk("\n"); @@ -1164,3 +1175,14 @@ static int __init kstack_setup(char *s) return 0; } early_param("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);