diff options
Diffstat (limited to 'arch/arm/kernel/stacktrace.c')
| -rw-r--r-- | arch/arm/kernel/stacktrace.c | 62 |
1 files changed, 56 insertions, 6 deletions
diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index 00f79e59985..f065eb05d25 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -3,6 +3,7 @@ #include <linux/stacktrace.h> #include <asm/stacktrace.h> +#include <asm/traps.h> #if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND) /* @@ -31,7 +32,7 @@ int notrace unwind_frame(struct stackframe *frame) high = ALIGN(low, THREAD_SIZE); /* check current frame pointer is within bounds */ - if (fp < (low + 12) || fp + 4 >= high) + if (fp < low + 12 || fp > high - 4) return -EINVAL; /* restore the registers from the stack frame */ @@ -61,6 +62,7 @@ EXPORT_SYMBOL(walk_stackframe); #ifdef CONFIG_STACKTRACE struct stack_trace_data { struct stack_trace *trace; + unsigned long last_pc; unsigned int no_sched_functions; unsigned int skip; }; @@ -69,6 +71,7 @@ static int save_trace(struct stackframe *frame, void *d) { struct stack_trace_data *data = d; struct stack_trace *trace = data->trace; + struct pt_regs *regs; unsigned long addr = frame->pc; if (data->no_sched_functions && in_sched_functions(addr)) @@ -80,16 +83,39 @@ static int save_trace(struct stackframe *frame, void *d) trace->entries[trace->nr_entries++] = addr; + if (trace->nr_entries >= trace->max_entries) + return 1; + + /* + * in_exception_text() is designed to test if the PC is one of + * the functions which has an exception stack above it, but + * unfortunately what is in frame->pc is the return LR value, + * not the saved PC value. So, we need to track the previous + * frame PC value when doing this. + */ + addr = data->last_pc; + data->last_pc = frame->pc; + if (!in_exception_text(addr)) + return 0; + + regs = (struct pt_regs *)frame->sp; + + trace->entries[trace->nr_entries++] = regs->ARM_pc; + return trace->nr_entries >= trace->max_entries; } -void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) +/* This must be noinline to so that our skip calculation works correctly */ +static noinline void __save_stack_trace(struct task_struct *tsk, + struct stack_trace *trace, unsigned int nosched) { struct stack_trace_data data; struct stackframe frame; data.trace = trace; + data.last_pc = ULONG_MAX; data.skip = trace->skip; + data.no_sched_functions = nosched; if (tsk != current) { #ifdef CONFIG_SMP @@ -102,7 +128,6 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) trace->entries[trace->nr_entries++] = ULONG_MAX; return; #else - data.no_sched_functions = 1; frame.fp = thread_saved_fp(tsk); frame.sp = thread_saved_sp(tsk); frame.lr = 0; /* recovered from the stack */ @@ -111,11 +136,12 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) } else { register unsigned long current_sp asm ("sp"); - data.no_sched_functions = 0; + /* We don't want this function nor the caller */ + data.skip += 2; frame.fp = (unsigned long)__builtin_frame_address(0); frame.sp = current_sp; frame.lr = (unsigned long)__builtin_return_address(0); - frame.pc = (unsigned long)save_stack_trace_tsk; + frame.pc = (unsigned long)__save_stack_trace; } walk_stackframe(&frame, save_trace, &data); @@ -123,9 +149,33 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) trace->entries[trace->nr_entries++] = ULONG_MAX; } +void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) +{ + struct stack_trace_data data; + struct stackframe frame; + + data.trace = trace; + data.skip = trace->skip; + data.no_sched_functions = 0; + + frame.fp = regs->ARM_fp; + frame.sp = regs->ARM_sp; + frame.lr = regs->ARM_lr; + frame.pc = regs->ARM_pc; + + walk_stackframe(&frame, save_trace, &data); + if (trace->nr_entries < trace->max_entries) + trace->entries[trace->nr_entries++] = ULONG_MAX; +} + +void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) +{ + __save_stack_trace(tsk, trace, 1); +} + void save_stack_trace(struct stack_trace *trace) { - save_stack_trace_tsk(current, trace); + __save_stack_trace(current, trace, 0); } EXPORT_SYMBOL_GPL(save_stack_trace); #endif |