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https://gitee.com/bianbu-linux/linux-6.6
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da885a0e5e
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: Arnaldo Carvalho de Melo <acme@redhat.com>
38 lines
1.2 KiB
C
38 lines
1.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __LIBPERF_INTERNAL_CPUMAP_H
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#define __LIBPERF_INTERNAL_CPUMAP_H
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#include <linux/refcount.h>
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#include <perf/cpumap.h>
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#include <internal/rc_check.h>
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/**
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* A sized, reference counted, sorted array of integers representing CPU
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* numbers. This is commonly used to capture which CPUs a PMU is associated
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* with. The indices into the cpumap are frequently used as they avoid having
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* gaps if CPU numbers were used. For events associated with a pid, rather than
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* a CPU, a single dummy map with an entry of -1 is used.
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*/
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DECLARE_RC_STRUCT(perf_cpu_map) {
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refcount_t refcnt;
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/** Length of the map array. */
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int nr;
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/** The CPU values. */
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struct perf_cpu map[];
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};
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#ifndef MAX_NR_CPUS
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#define MAX_NR_CPUS 2048
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#endif
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struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus);
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int perf_cpu_map__idx(const struct perf_cpu_map *cpus, struct perf_cpu cpu);
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bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu_map *b);
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void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus);
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static inline refcount_t *perf_cpu_map__refcnt(struct perf_cpu_map *map)
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{
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return &RC_CHK_ACCESS(map)->refcnt;
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}
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#endif /* __LIBPERF_INTERNAL_CPUMAP_H */
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