From 4a7ca524d58b0c6e24ad2645eab52937ec4ab6f8 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 26 Jun 2006 13:57:47 +0200 Subject: [PATCH] [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/i386/kernel/traps.c | 46 +++++++++++++++++++++++---------- arch/x86_64/kernel/traps.c | 51 +++++++++++++++++++++++++------------ include/asm-i386/unwind.h | 8 +++--- include/asm-x86_64/unwind.h | 8 +++--- include/linux/unwind.h | 8 +++--- kernel/unwind.c | 7 +++-- 6 files changed, 83 insertions(+), 45 deletions(-) diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index 2865846678652..78464097470a2 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -93,6 +93,7 @@ asmlinkage void spurious_interrupt_bug(void); asmlinkage void machine_check(void); static int kstack_depth_to_print = 24; +static int call_trace = 1; ATOMIC_NOTIFIER_HEAD(i386die_chain); int register_die_notifier(struct notifier_block *nb) @@ -171,40 +172,47 @@ static inline unsigned long print_context_stack(struct thread_info *tinfo, return ebp; } -static asmlinkage void show_trace_unwind(struct unwind_frame_info *info, void *log_lvl) +static asmlinkage int show_trace_unwind(struct unwind_frame_info *info, void *log_lvl) { + int n = 0; int printed = 0; /* nr of entries already printed on current line */ while (unwind(info) == 0 && UNW_PC(info)) { + ++n; printed = print_addr_and_symbol(UNW_PC(info), log_lvl, printed); if (arch_unw_user_mode(info)) break; } if (printed) printk("\n"); + return n; } static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, unsigned long *stack, char *log_lvl) { unsigned long ebp; - struct unwind_frame_info info; if (!task) task = current; - if (regs) { - if (unwind_init_frame_info(&info, task, regs) == 0) { - show_trace_unwind(&info, log_lvl); - return; + if (call_trace >= 0) { + int unw_ret = 0; + struct unwind_frame_info info; + + if (regs) { + if (unwind_init_frame_info(&info, task, regs) == 0) + unw_ret = show_trace_unwind(&info, log_lvl); + } else if (task == current) + unw_ret = unwind_init_running(&info, show_trace_unwind, log_lvl); + else { + if (unwind_init_blocked(&info, task) == 0) + unw_ret = show_trace_unwind(&info, log_lvl); } - } else if (task == current) { - if (unwind_init_running(&info, show_trace_unwind, log_lvl) == 0) - return; - } else { - if (unwind_init_blocked(&info, task) == 0) { - show_trace_unwind(&info, log_lvl); - return; + if (unw_ret > 0) { + if (call_trace > 0) + return; + printk("%sLegacy call trace:\n", log_lvl); } } @@ -1245,3 +1253,15 @@ static int __init kstack_setup(char *s) return 1; } __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); diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c index eb1534ff1f5f0..bd0891f4c2c7d 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); diff --git a/include/asm-i386/unwind.h b/include/asm-i386/unwind.h index 1c076897ac21f..d480f2e38215d 100644 --- a/include/asm-i386/unwind.h +++ b/include/asm-i386/unwind.h @@ -66,10 +66,10 @@ static inline void arch_unw_init_blocked(struct unwind_frame_info *info) info->regs.xes = __USER_DS; } -extern asmlinkage void arch_unwind_init_running(struct unwind_frame_info *, - asmlinkage void (*callback)(struct unwind_frame_info *, - void *arg), - void *arg); +extern asmlinkage int arch_unwind_init_running(struct unwind_frame_info *, + asmlinkage int (*callback)(struct unwind_frame_info *, + void *arg), + void *arg); static inline int arch_unw_user_mode(const struct unwind_frame_info *info) { diff --git a/include/asm-x86_64/unwind.h b/include/asm-x86_64/unwind.h index 4f61de246179b..f3e7124effe31 100644 --- a/include/asm-x86_64/unwind.h +++ b/include/asm-x86_64/unwind.h @@ -75,10 +75,10 @@ static inline void arch_unw_init_blocked(struct unwind_frame_info *info) info->regs.ss = __KERNEL_DS; } -extern void arch_unwind_init_running(struct unwind_frame_info *, - void (*callback)(struct unwind_frame_info *, - void *arg), - void *arg); +extern int arch_unwind_init_running(struct unwind_frame_info *, + int (*callback)(struct unwind_frame_info *, + void *arg), + void *arg); static inline int arch_unw_user_mode(const struct unwind_frame_info *info) { diff --git a/include/linux/unwind.h b/include/linux/unwind.h index 0295aa789ab43..13c7b2cd87ce1 100644 --- a/include/linux/unwind.h +++ b/include/linux/unwind.h @@ -49,8 +49,8 @@ extern int unwind_init_blocked(struct unwind_frame_info *, * Prepare to unwind the currently running thread. */ extern int unwind_init_running(struct unwind_frame_info *, - asmlinkage void (*callback)(struct unwind_frame_info *, - void *arg), + asmlinkage int (*callback)(struct unwind_frame_info *, + void *arg), void *arg); /* @@ -97,8 +97,8 @@ static inline int unwind_init_blocked(struct unwind_frame_info *info, } static inline int unwind_init_running(struct unwind_frame_info *info, - asmlinkage void (*cb)(struct unwind_frame_info *, - void *arg), + asmlinkage int (*cb)(struct unwind_frame_info *, + void *arg), void *arg) { return -ENOSYS; diff --git a/kernel/unwind.c b/kernel/unwind.c index d36bcd3ad3b5d..0421035272d99 100644 --- a/kernel/unwind.c +++ b/kernel/unwind.c @@ -885,14 +885,13 @@ EXPORT_SYMBOL(unwind_init_blocked); * Prepare to unwind the currently running thread. */ int unwind_init_running(struct unwind_frame_info *info, - asmlinkage void (*callback)(struct unwind_frame_info *, - void *arg), + asmlinkage int (*callback)(struct unwind_frame_info *, + void *arg), void *arg) { info->task = current; - arch_unwind_init_running(info, callback, arg); - return 0; + return arch_unwind_init_running(info, callback, arg); } EXPORT_SYMBOL(unwind_init_running); -- 2.39.5