From c33bd9aac0597eeedaaa01ea5aafe456894b2f2b Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 26 Jun 2006 13:57:47 +0200 Subject: [PATCH] i386/x86-64: fall back to old-style call trace if no unwinding If no unwinding is possible at all for a certain exception instance, fall back to the old style call trace instead of not showing any trace at all. Also, allow setting the stack trace mode at the command line. Signed-off-by: Jan Beulich Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/traps.c | 51 +++++++++++++++++++++++++++++++--------------- 1 file changed, 35 insertions(+), 16 deletions(-) (limited to 'arch/x86_64') diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c index eb1534ff1f5..bd0891f4c2c 100644 --- a/arch/x86_64/kernel/traps.c +++ b/arch/x86_64/kernel/traps.c @@ -107,6 +107,7 @@ static inline void preempt_conditional_cli(struct pt_regs *regs) } static int kstack_depth_to_print = 10; +static int call_trace = 1; #ifdef CONFIG_KALLSYMS #include @@ -190,11 +191,12 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack, return NULL; } -static void show_trace_unwind(struct unwind_frame_info *info, void *context) +static int show_trace_unwind(struct unwind_frame_info *info, void *context) { - int i = 11; + int i = 11, n = 0; while (unwind(info) == 0 && UNW_PC(info)) { + ++n; if (i > 50) { printk("\n "); i = 7; @@ -205,6 +207,7 @@ static void show_trace_unwind(struct unwind_frame_info *info, void *context) break; } printk("\n"); + return n; } /* @@ -218,27 +221,32 @@ void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s { const unsigned cpu = safe_smp_processor_id(); unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr; - int i; + int i = 11; unsigned used = 0; - struct unwind_frame_info info; printk("\nCall Trace:"); if (!tsk) tsk = current; - if (regs) { - if (unwind_init_frame_info(&info, tsk, regs) == 0) { - show_trace_unwind(&info, NULL); - return; + if (call_trace >= 0) { + int unw_ret = 0; + struct unwind_frame_info info; + + if (regs) { + if (unwind_init_frame_info(&info, tsk, regs) == 0) + unw_ret = show_trace_unwind(&info, NULL); + } else if (tsk == current) + unw_ret = unwind_init_running(&info, show_trace_unwind, NULL); + else { + if (unwind_init_blocked(&info, tsk) == 0) + unw_ret = show_trace_unwind(&info, NULL); } - } else if (tsk == current) { - if (unwind_init_running(&info, show_trace_unwind, NULL) == 0) - return; - } else { - if (unwind_init_blocked(&info, tsk) == 0) { - show_trace_unwind(&info, NULL); - return; + if (unw_ret > 0) { + if (call_trace > 0) + return; + printk("Legacy call trace:"); + i = 18; } } @@ -264,7 +272,7 @@ void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s } \ } while (0) - for(i = 11; ; ) { + for(; ; ) { const char *id; unsigned long *estack_end; estack_end = in_exception_stack(cpu, (unsigned long)stack, @@ -1052,3 +1060,14 @@ static int __init kstack_setup(char *s) } __setup("kstack=", kstack_setup); +static int __init call_trace_setup(char *s) +{ + if (strcmp(s, "old") == 0) + call_trace = -1; + else if (strcmp(s, "both") == 0) + call_trace = 0; + else if (strcmp(s, "new") == 0) + call_trace = 1; + return 1; +} +__setup("call_trace=", call_trace_setup); -- cgit v1.2.3