diff options
author | Masami Hiramatsu <mhiramat@kernel.org> | 2021-09-14 23:42:31 +0900 |
---|---|---|
committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-09-30 21:24:07 -0400 |
commit | 19138af1bd880d52318bbb164de72a482e59a45c (patch) | |
tree | 9db80a06be737e198f3d1d2b2a49add41c41c9ff /arch/x86/kernel/unwind_frame.c | |
parent | 1f36839308cf8d7d9d35586029f8ae4322e18ef5 (diff) |
x86/unwind: Recover kretprobe trampoline entry
Since the kretprobe replaces the function return address with
the kretprobe_trampoline on the stack, x86 unwinders can not
continue the stack unwinding at that point, or record
kretprobe_trampoline instead of correct return address.
To fix this issue, find the correct return address from task's
kretprobe_instances as like as function-graph tracer does.
With this fix, the unwinder can correctly unwind the stack
from kretprobe event on x86, as below.
<...>-135 [003] ...1 6.722338: r_full_proxy_read_0: (vfs_read+0xab/0x1a0 <- full_proxy_read)
<...>-135 [003] ...1 6.722377: <stack trace>
=> kretprobe_trace_func+0x209/0x2f0
=> kretprobe_dispatcher+0x4a/0x70
=> __kretprobe_trampoline_handler+0xca/0x150
=> trampoline_handler+0x44/0x70
=> kretprobe_trampoline+0x2a/0x50
=> vfs_read+0xab/0x1a0
=> ksys_read+0x5f/0xe0
=> do_syscall_64+0x33/0x40
=> entry_SYSCALL_64_after_hwframe+0x44/0xae
Link: https://lkml.kernel.org/r/163163055130.489837.5161749078833497255.stgit@devnote2
Reported-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch/x86/kernel/unwind_frame.c')
-rw-r--r-- | arch/x86/kernel/unwind_frame.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c index d7c44b257f7f..8e1c50c86e5d 100644 --- a/arch/x86/kernel/unwind_frame.c +++ b/arch/x86/kernel/unwind_frame.c @@ -240,8 +240,7 @@ static bool update_stack_state(struct unwind_state *state, else { addr_p = unwind_get_return_address_ptr(state); addr = READ_ONCE_TASK_STACK(state->task, *addr_p); - state->ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, - addr, addr_p); + state->ip = unwind_recover_ret_addr(state, addr, addr_p); } /* Save the original stack pointer for unwind_dump(): */ |