From f6054e2131d8f5d43f6686ecc7687994adecc5a2 Mon Sep 17 00:00:00 2001 From: Sebastian Siewior Date: Thu, 1 May 2008 12:16:38 +1000 Subject: [PATCH] m68knommu: add pretty back strace With this patch and CONFIG_FRAME_POINTER=y CONFIG_KALLSYMS=y The backtrace shows resolved function names and their numeric address. Signed-off-by: Sebastian Siewior Signed-off-by: Greg Ungerer Signed-off-by: Linus Torvalds --- arch/m68knommu/kernel/traps.c | 88 +++++++++++++++++++++-------------- 1 file changed, 54 insertions(+), 34 deletions(-) diff --git a/arch/m68knommu/kernel/traps.c b/arch/m68knommu/kernel/traps.c index 437a061d8b9..ec9aea652e7 100644 --- a/arch/m68knommu/kernel/traps.c +++ b/arch/m68knommu/kernel/traps.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -102,56 +103,47 @@ asmlinkage void buserr_c(struct frame *fp) force_sig(SIGSEGV, current); } - int kstack_depth_to_print = 48; -void show_stack(struct task_struct *task, unsigned long *stack) +static void __show_stack(struct task_struct *task, unsigned long *stack) { unsigned long *endstack, addr; - extern char _start, _etext; + unsigned long *last_stack; int i; - if (!stack) { - if (task) - stack = (unsigned long *)task->thread.ksp; - else - stack = (unsigned long *)&stack; - } + if (!stack) + stack = (unsigned long *)task->thread.ksp; addr = (unsigned long) stack; endstack = (unsigned long *) PAGE_ALIGN(addr); printk(KERN_EMERG "Stack from %08lx:", (unsigned long)stack); for (i = 0; i < kstack_depth_to_print; i++) { - if (stack + 1 > endstack) + if (stack + 1 + i > endstack) break; if (i % 8 == 0) printk("\n" KERN_EMERG " "); - printk(" %08lx", *stack++); + printk(" %08lx", *(stack + i)); } printk("\n"); - printk(KERN_EMERG "Call Trace:"); - i = 0; - while (stack + 1 <= endstack) { - addr = *stack++; - /* - * If the address is either in the text segment of the - * kernel, or in the region which contains vmalloc'ed - * memory, it *may* be the address of a calling - * routine; if so, print it so that someone tracing - * down the cause of the crash will be able to figure - * out the call path that was taken. - */ - if (((addr >= (unsigned long) &_start) && - (addr <= (unsigned long) &_etext))) { - if (i % 4 == 0) - printk("\n" KERN_EMERG " "); - printk(" [<%08lx>]", addr); - i++; - } +#ifdef CONFIG_FRAME_POINTER + printk(KERN_EMERG "Call Trace:\n"); + + last_stack = stack - 1; + while (stack <= endstack && stack > last_stack) { + + addr = *(stack + 1); + printk(KERN_EMERG " [%08lx] ", addr); + print_symbol(KERN_CONT "%s\n", addr); + + last_stack = stack; + stack = (unsigned long *)*stack; } printk("\n"); +#else + printk(KERN_EMERG "CONFIG_FRAME_POINTER disabled, no symbolic call trace\n"); +#endif } void bad_super_trap(struct frame *fp) @@ -298,19 +290,47 @@ asmlinkage void set_esp0(unsigned long ssp) current->thread.esp0 = ssp; } - /* * The architecture-independent backtrace generator */ void dump_stack(void) { - unsigned long stack; + /* + * We need frame pointers for this little trick, which works as follows: + * + * +------------+ 0x00 + * | Next SP | -> 0x0c + * +------------+ 0x04 + * | Caller | + * +------------+ 0x08 + * | Local vars | -> our stack var + * +------------+ 0x0c + * | Next SP | -> 0x18, that is what we pass to show_stack() + * +------------+ 0x10 + * | Caller | + * +------------+ 0x14 + * | Local vars | + * +------------+ 0x18 + * | ... | + * +------------+ + */ - show_stack(current, &stack); -} + unsigned long *stack; + stack = (unsigned long *)&stack; + stack++; + __show_stack(current, stack); +} EXPORT_SYMBOL(dump_stack); +void show_stack(struct task_struct *task, unsigned long *stack) +{ + if (!stack && !task) + dump_stack(); + else + __show_stack(task, stack); +} + #ifdef CONFIG_M68KFPU_EMU asmlinkage void fpemu_signal(int signal, int code, void *addr) { -- 2.20.1