Commit 302fa4b5 authored by Arun Sharma's avatar Arun Sharma Committed by Ingo Molnar

perf/x86: Allow multiple stacks

Without this patch, applications with two different stack
regions (eg: native stack vs JIT stack) get truncated
callchains even when RBP chaining is present. GDB shows proper
stack traces and the frame pointer chaining is intact.

This patch disables the (fp < RSP) check, hoping that other checks
in the code save the day for us. In our limited testing, this
didn't seem to break anything.

In the long term, we could potentially have userspace advise
the kernel on the range of valid stack addresses, so we don't
spend a lot of time unwinding from bogus addresses.
Signed-off-by: default avatarArun Sharma <asharma@fb.com>
CC: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1334961696-19580-2-git-send-email-asharma@fb.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 8440ccb4
...@@ -1781,9 +1781,6 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry) ...@@ -1781,9 +1781,6 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
if (bytes != sizeof(frame)) if (bytes != sizeof(frame))
break; break;
if (fp < compat_ptr(regs->sp))
break;
perf_callchain_store(entry, frame.return_address); perf_callchain_store(entry, frame.return_address);
fp = compat_ptr(frame.next_frame); fp = compat_ptr(frame.next_frame);
} }
...@@ -1827,9 +1824,6 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs) ...@@ -1827,9 +1824,6 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
if (bytes != sizeof(frame)) if (bytes != sizeof(frame))
break; break;
if ((unsigned long)fp < regs->sp)
break;
perf_callchain_store(entry, frame.return_address); perf_callchain_store(entry, frame.return_address);
fp = frame.next_frame; fp = frame.next_frame;
} }
......
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