diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/Kconfig | 8 | ||||
| -rw-r--r-- | kernel/trace/trace_functions_graph.c | 36 |
2 files changed, 40 insertions, 4 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 4a13e5a01ce..b17ed8787de 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -18,6 +18,13 @@ config HAVE_FUNCTION_TRACER config HAVE_FUNCTION_GRAPH_TRACER bool +config HAVE_FUNCTION_GRAPH_FP_TEST + bool + help + An arch may pass in a unique value (frame pointer) to both the + entering and exiting of a function. On exit, the value is compared + and if it does not match, then it will panic the kernel. + config HAVE_FUNCTION_TRACE_MCOUNT_TEST bool help @@ -121,6 +128,7 @@ config FUNCTION_GRAPH_TRACER bool "Kernel Function Graph Tracer" depends on HAVE_FUNCTION_GRAPH_TRACER depends on FUNCTION_TRACER + depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE default y help Enable the kernel to trace a function at both its return diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 8b592418d8b..d2249abafb5 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -57,7 +57,8 @@ static struct tracer_flags tracer_flags = { /* Add a function return address to the trace stack on thread info.*/ int -ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth) +ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, + unsigned long frame_pointer) { unsigned long long calltime; int index; @@ -85,6 +86,7 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth) current->ret_stack[index].func = func; current->ret_stack[index].calltime = calltime; current->ret_stack[index].subtime = 0; + current->ret_stack[index].fp = frame_pointer; *depth = index; return 0; @@ -92,7 +94,8 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth) /* Retrieve a function return address to the trace stack on thread info.*/ static void -ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret) +ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, + unsigned long frame_pointer) { int index; @@ -106,6 +109,31 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret) return; } +#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST + /* + * The arch may choose to record the frame pointer used + * and check it here to make sure that it is what we expect it + * to be. If gcc does not set the place holder of the return + * address in the frame pointer, and does a copy instead, then + * the function graph trace will fail. This test detects this + * case. + * + * Currently, x86_32 with optimize for size (-Os) makes the latest + * gcc do the above. + */ + if (unlikely(current->ret_stack[index].fp != frame_pointer)) { + ftrace_graph_stop(); + WARN(1, "Bad frame pointer: expected %lx, received %lx\n" + " from func %pF return to %lx\n", + current->ret_stack[index].fp, + frame_pointer, + (void *)current->ret_stack[index].func, + current->ret_stack[index].ret); + *ret = (unsigned long)panic; + return; + } +#endif + *ret = current->ret_stack[index].ret; trace->func = current->ret_stack[index].func; trace->calltime = current->ret_stack[index].calltime; @@ -117,12 +145,12 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret) * Send the trace to the ring-buffer. * @return the original return address. */ -unsigned long ftrace_return_to_handler(void) +unsigned long ftrace_return_to_handler(unsigned long frame_pointer) { struct ftrace_graph_ret trace; unsigned long ret; - ftrace_pop_return_trace(&trace, &ret); + ftrace_pop_return_trace(&trace, &ret, frame_pointer); trace.rettime = trace_clock_local(); ftrace_graph_return(&trace); barrier(); |