diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index 309bfa4a1520..951bf9ca3ce9 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -448,15 +448,16 @@ unsigned long get_wchan(struct task_struct *p) } #ifdef CONFIG_KALLSYMS -/* used by show_frametrace() */ -unsigned long unwind_stack(struct task_struct *task, - unsigned long **sp, unsigned long pc) +/* used by show_backtrace() */ +unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, + unsigned long pc, unsigned long ra) { unsigned long stack_page; struct mips_frame_info info; char *modname; char namebuf[KSYM_NAME_LEN + 1]; unsigned long size, ofs; + int leaf; stack_page = (unsigned long)task_stack_page(task); if (!stack_page) @@ -469,18 +470,26 @@ unsigned long unwind_stack(struct task_struct *task, info.func = (void *)(pc - ofs); info.func_size = ofs; /* analyze from start to ofs */ - if (get_frame_info(&info)) { - /* leaf or unknown */ - *sp += info.frame_size / sizeof(long); - return 0; - } - if ((unsigned long)*sp < stack_page || - (unsigned long)*sp + info.frame_size / sizeof(long) > - stack_page + THREAD_SIZE - 32) + leaf = get_frame_info(&info); + if (leaf < 0) return 0; - pc = (*sp)[info.pc_offset]; - *sp += info.frame_size / sizeof(long); - return pc; + if (*sp < stack_page || + *sp + info.frame_size > stack_page + THREAD_SIZE - 32) + return 0; + + if (leaf) + /* + * For some extreme cases, get_frame_info() can + * consider wrongly a nested function as a leaf + * one. In that cases avoid to return always the + * same value. + */ + pc = pc != ra ? ra : 0; + else + pc = ((unsigned long *)(*sp))[info.pc_offset]; + + *sp += info.frame_size; + return __kernel_text_address(pc) ? pc : 0; } #endif diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 303f00843021..ab77034921c4 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -74,8 +74,9 @@ void (*board_ejtag_handler_setup)(void); void (*board_bind_eic_interrupt)(int irq, int regset); -static void show_raw_backtrace(unsigned long *sp) +static void show_raw_backtrace(unsigned long reg29) { + unsigned long *sp = (unsigned long *)reg29; unsigned long addr; printk("Call Trace:"); @@ -99,30 +100,29 @@ static int __init set_raw_show_trace(char *str) } __setup("raw_show_trace", set_raw_show_trace); -extern unsigned long unwind_stack(struct task_struct *task, - unsigned long **sp, unsigned long pc); +extern unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, + unsigned long pc, unsigned long ra); + static void show_backtrace(struct task_struct *task, struct pt_regs *regs) { - unsigned long *sp = (long *)regs->regs[29]; + unsigned long sp = regs->regs[29]; + unsigned long ra = regs->regs[31]; unsigned long pc = regs->cp0_epc; - int top = 1; if (raw_show_trace || !__kernel_text_address(pc)) { show_raw_backtrace(sp); return; } printk("Call Trace:\n"); - while (__kernel_text_address(pc)) { + do { print_ip_sym(pc); - pc = unwind_stack(task, &sp, pc); - if (top && pc == 0) - pc = regs->regs[31]; /* leaf? */ - top = 0; - } + pc = unwind_stack(task, &sp, pc, ra); + ra = 0; + } while (pc); printk("\n"); } #else -#define show_backtrace(task, r) show_raw_backtrace((long *)(r)->regs[29]); +#define show_backtrace(task, r) show_raw_backtrace((r)->regs[29]); #endif /*