| Message ID | 1444298504-10392-4-git-send-email-takahiro.akashi@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi AKASHI,
[auto build test ERROR on v4.3-rc4 -- if it's inappropriate base, please ignore]
config: arm64-allmodconfig (attached as .config)
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=arm64
Note: the linux-review/AKASHI-Takahiro/arm64-ftrace-fix-incorrect-output-from-stack-tracer HEAD f6c03913c640aa1d196348c49f15cfdc264393e0 builds fine.
It only hurts bisectibility.
All errors (new ones prefixed by >>):
arch/arm64/kernel/stacktrace.c: In function 'save_trace':
>> arch/arm64/kernel/stacktrace.c:93:29: error: 'return_to_handler' undeclared (first use in this function)
if (addr == (unsigned long)return_to_handler - AARCH64_INSN_SIZE) {
^
arch/arm64/kernel/stacktrace.c:93:29: note: each undeclared identifier is reported only once for each function it appears in
>> arch/arm64/kernel/stacktrace.c:101:4: error: invalid use of undefined type 'struct ftrace_ret_stack'
current->ret_stack[data->ret_stack_index--].ret
^
>> arch/arm64/kernel/stacktrace.c:101:22: error: dereferencing pointer to incomplete type
current->ret_stack[data->ret_stack_index--].ret
^
vim +/return_to_handler +93 arch/arm64/kernel/stacktrace.c
87 {
88 struct stack_trace_data *data = d;
89 struct stack_trace *trace = data->trace;
90 unsigned long addr = frame->pc;
91
92 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> 93 if (addr == (unsigned long)return_to_handler - AARCH64_INSN_SIZE) {
94 /*
95 * This is a case where function graph tracer has
96 * modified a return address (LR) in a stack frame
97 * to hook a function return.
98 * So replace it to an original value.
99 */
100 frame->pc = addr =
> 101 current->ret_stack[data->ret_stack_index--].ret
102 - AARCH64_INSN_SIZE;
103 }
104 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h index 2b43e20..b7d597c 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -29,6 +29,8 @@ struct dyn_arch_ftrace { extern unsigned long ftrace_graph_call; +extern void return_to_handler(void); + static inline unsigned long ftrace_call_adjust(unsigned long addr) { /* diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index bc0689a..1555a8b 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -78,6 +78,9 @@ struct stack_trace_data { struct stack_trace *trace; unsigned int no_sched_functions; unsigned int skip; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + unsigned int ret_stack_index; +#endif }; static int save_trace(struct stackframe *frame, void *d) @@ -86,6 +89,20 @@ static int save_trace(struct stackframe *frame, void *d) struct stack_trace *trace = data->trace; unsigned long addr = frame->pc; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + if (addr == (unsigned long)return_to_handler - AARCH64_INSN_SIZE) { + /* + * This is a case where function graph tracer has + * modified a return address (LR) in a stack frame + * to hook a function return. + * So replace it to an original value. + */ + frame->pc = addr = + current->ret_stack[data->ret_stack_index--].ret + - AARCH64_INSN_SIZE; + } +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + if (data->no_sched_functions && in_sched_functions(addr)) return 0; if (data->skip) { @@ -105,6 +122,9 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) data.trace = trace; data.skip = trace->skip; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + data.ret_stack_index = current->curr_ret_stack; +#endif if (tsk != current) { data.no_sched_functions = 1;
Function graph tracer modifies a return address (LR) in a stack frame to hook a function return. This will result in many useless entries (return_to_handler) showing up in a stack tracer's output. This patch replaces such entries with originals values preserved in current->ret_stack[]. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> --- arch/arm64/include/asm/ftrace.h | 2 ++ arch/arm64/kernel/stacktrace.c | 20 ++++++++++++++++++++ 2 files changed, 22 insertions(+)