From: Josh Poimboeuf <jpoimboe@redhat.com>
To: x86@kernel.org, Alexei Starovoitov <ast@kernel.org>
Cc: linux-kernel@vger.kernel.org,
Daniel Borkmann <daniel@iogearbox.net>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Song Liu <songliubraving@fb.com>, Kairui Song <kasong@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
David Laight <David.Laight@ACULAB.COM>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@kernel.org>
Subject: [PATCH v2 1/5] perf/x86: Always store regs->ip in perf_callchain_kernel()
Date: Fri, 14 Jun 2019 12:56:40 -0500 [thread overview]
Message-ID: <81b0cdc5aa276dac315a0536df384cc82da86243.1560534694.git.jpoimboe@redhat.com> (raw)
In-Reply-To: <cover.1560534694.git.jpoimboe@redhat.com>
From: Song Liu <songliubraving@fb.com>
The stacktrace_map_raw_tp BPF selftest is failing because the RIP saved
by perf_arch_fetch_caller_regs() isn't getting saved by
perf_callchain_kernel().
This was broken by the following commit:
d15d356887e7 ("perf/x86: Make perf callchains work without CONFIG_FRAME_POINTER")
With that change, when starting with non-HW regs, the unwinder starts
with the current stack frame and unwinds until it passes up the frame
which called perf_arch_fetch_caller_regs(). So regs->ip needs to be
saved deliberately.
Fixes: d15d356887e7 ("perf/x86: Make perf callchains work without CONFIG_FRAME_POINTER")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/events/core.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index f0e4804515d8..6a7cfcadfc1e 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2328,13 +2328,13 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
return;
}
- if (perf_hw_regs(regs)) {
- if (perf_callchain_store(entry, regs->ip))
- return;
+ if (perf_callchain_store(entry, regs->ip))
+ return;
+
+ if (perf_hw_regs(regs))
unwind_start(&state, current, regs, NULL);
- } else {
+ else
unwind_start(&state, current, NULL, (void *)regs->sp);
- }
for (; !unwind_done(&state); unwind_next_frame(&state)) {
addr = unwind_get_return_address(&state);
--
2.20.1
next prev parent reply other threads:[~2019-06-14 18:00 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-14 17:56 [PATCH v2 0/5] x86/bpf: unwinder fixes Josh Poimboeuf
2019-06-14 17:56 ` Josh Poimboeuf [this message]
2019-06-14 20:56 ` [PATCH v2 1/5] perf/x86: Always store regs->ip in perf_callchain_kernel() Alexei Starovoitov
2019-06-14 21:06 ` Josh Poimboeuf
2019-06-14 21:16 ` Steven Rostedt
2019-06-14 21:20 ` Song Liu
2019-06-14 17:56 ` [PATCH v2 2/5] objtool: Fix ORC unwinding in non-JIT BPF generated code Josh Poimboeuf
2019-06-14 20:58 ` Alexei Starovoitov
2019-06-14 21:07 ` Josh Poimboeuf
2019-06-14 21:09 ` Alexei Starovoitov
2019-06-14 21:19 ` Josh Poimboeuf
2019-06-14 21:22 ` Alexei Starovoitov
2019-06-14 23:17 ` Josh Poimboeuf
2019-06-14 23:30 ` Alexei Starovoitov
2019-06-15 0:02 ` Josh Poimboeuf
2019-06-15 0:06 ` abhja kaanlani
2019-06-15 0:07 ` Alexei Starovoitov
2019-06-17 14:57 ` David Laight
2019-06-14 17:56 ` [PATCH v2 3/5] x86/bpf: Move epilogue generation to a dedicated function Josh Poimboeuf
2019-06-14 17:56 ` [PATCH v2 4/5] x86/bpf: Fix 64-bit JIT frame pointer usage Josh Poimboeuf
2019-06-14 21:05 ` Alexei Starovoitov
2019-06-14 21:19 ` Josh Poimboeuf
2019-06-14 21:27 ` Alexei Starovoitov
2019-06-14 23:13 ` Josh Poimboeuf
2019-06-14 23:23 ` Alexei Starovoitov
2019-06-14 23:54 ` Josh Poimboeuf
2019-06-15 0:02 ` Alexei Starovoitov
2019-06-15 4:27 ` Josh Poimboeuf
2019-06-15 5:16 ` Alexei Starovoitov
2019-06-15 12:57 ` Josh Poimboeuf
2019-06-14 17:56 ` [PATCH v2 5/5] x86/unwind/orc: Fall back to using frame pointers for generated code Josh Poimboeuf
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