perf lock: Avoid segv if event is missing a callchain

Avoid a potential segmentation fault if a parsed sample unexpectedly lacks a
valid callchain pointer.

Add a check for a NULL sample->callchain pointer in get_callstack(). If the
callchain is missing, return NULL to safely skip the event and log a debug
warning rather than causing a tool segfault.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Jones <ajones@ventanamicro.com>
Cc: Anup Patel <anup@brainfault.org>
Cc: Athira Rajeev <atrajeev@linux.ibm.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Chen Ni <nichen@iscas.ac.cn>
Cc: Chun-Tse Shao <ctshao@google.com>
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Derek Foreman <derek.foreman@collabora.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Dr. David Alan Gilbert <linux@treblig.org>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Hrishikesh Suresh <hrishikesh123s@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <pjw@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quan Zhou <zhouquan@iscas.ac.cn>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Swapnil Sapkal <swapnil.sapkal@amd.com>
Cc: Thomas Falcon <thomas.falcon@intel.com>
Cc: Tianyou Li <tianyou.li@intel.com>
Cc: Yujie Liu <yujie.liu@intel.com>
Cc: tanze <tanze@kylinos.cn>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

0 files changed, 0 insertions, 0 deletions