• Ian Rogers's avatar
    perf cpumap: Add reference count checking · da885a0e
    Ian Rogers authored
    Enabled when REFCNT_CHECKING is defined. The change adds a memory
    allocated pointer that is interposed between the reference counted cpu
    map at a get and freed by a put. The pointer replaces the original
    perf_cpu_map struct, so use of the perf_cpu_map via APIs remains
    unchanged. Any use of the cpu map without the API requires two versions,
    handled via the RC_CHK_ACCESS macro.
    
    This change is intended to catch:
    
     - use after put: using a cpumap after you have put it will cause a
       segv.
     - unbalanced puts: two puts for a get will result in a double free
       that can be captured and reported by tools like address sanitizer,
       including with the associated stack traces of allocation and frees.
     - missing puts: if a put is missing then the get turns into a memory
       leak that can be reported by leak sanitizer, including the stack
       trace at the point the get occurs.
    
    Cc: Adrian Hunter <adrian.hunter@intel.com>
    Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
    Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
    Cc: Andi Kleen <ak@linux.intel.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
    Cc: Darren Hart <dvhart@infradead.org>
    Cc: Davidlohr Bueso <dave@stgolabs.net>
    Cc: Dmitriy Vyukov <dvyukov@google.com>
    Cc: Eric Dumazet <edumazet@google.com>
    Cc: German Gomez <german.gomez@arm.com>
    Cc: Hao Luo <haoluo@google.com>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: James Clark <james.clark@arm.com>
    Cc: Jiri Olsa <jolsa@kernel.org>
    Cc: John Garry <john.g.garry@oracle.com>
    Cc: Kajol Jain <kjain@linux.ibm.com>
    Cc: Kan Liang <kan.liang@linux.intel.com>
    Cc: Leo Yan <leo.yan@linaro.org>
    Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
    Cc: Mark Rutland <mark.rutland@arm.com>
    Cc: Masami Hiramatsu <mhiramat@kernel.org>
    Cc: Miaoqian Lin <linmq006@gmail.com>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Riccardo Mancini <rickyman7@gmail.com>
    Cc: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
    Cc: Song Liu <song@kernel.org>
    Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
    Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Thomas Richter <tmricht@linux.ibm.com>,
    Cc: Yury Norov <yury.norov@gmail.com>
    Link: https://lore.kernel.org/lkml/20230407230405.2931830-3-irogers@google.com
    [ Extracted from a larger patch ]
    Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    da885a0e
cpumap.c 15.3 KB