Messages in this thread Patch in this message | | | Date | Mon, 17 Apr 2023 18:30:14 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v7 3/5] perf namespaces: Add reference count checking |
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Em Fri, Apr 07, 2023 at 04:04:03PM -0700, Ian Rogers escreveu: > Add reference count checking controlled by REFCNT_CHECKING ifdef. The > reference count checking interposes an allocated pointer between the > reference counted struct on a get and frees the pointer on a put. > Accesses after a put cause faults and use after free, missed puts are > caughts as leaks and double puts are double frees. > > This checking helped resolve a memory leak and use after free: > https://lore.kernel.org/linux-perf-users/CAP-5=fWZH20L4kv-BwVtGLwR=Em3AOOT+Q4QGivvQuYn5AsPRg@mail.gmail.com/ > > Signed-off-by: Ian Rogers <irogers@google.com> > --- > tools/perf/builtin-inject.c | 2 +- > tools/perf/util/annotate.c | 2 +- > tools/perf/util/dso.c | 2 +- > tools/perf/util/dsos.c | 2 +- > tools/perf/util/namespaces.c | 132 ++++++++++++++++++++--------------- > tools/perf/util/namespaces.h | 3 +- > tools/perf/util/symbol.c | 2 +- > 7 files changed, 83 insertions(+), 62 deletions(-) > > diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c > index fd2b38458a5d..fe6ddcf7fb1e 100644 > --- a/tools/perf/builtin-inject.c > +++ b/tools/perf/builtin-inject.c > @@ -632,7 +632,7 @@ static int dso__read_build_id(struct dso *dso) > else if (dso->nsinfo) { > char *new_name; > > - new_name = filename_with_chroot(dso->nsinfo->pid, > + new_name = filename_with_chroot(RC_CHK_ACCESS(dso->nsinfo)->pid, > dso->long_name);
To reduce these:
From c80478cfc86cf24f6f075576d731d99e0fa8fe4f Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo <acme@redhat.com> Date: Mon, 17 Apr 2023 18:28:01 -0300 Subject: [PATCH 1/1] perf dso: Add dso__filename_with_chroot() to reduce number of accesses to dso->nsinfo members
We'll need to reference count dso->nsinfo, so reduce the number of direct accesses by having a shorter form of obtaining a filename with a chroot (namespace one).
Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Riccardo Mancini <rickyman7@gmail.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Link: https://lore.kernel.org/lkml/ Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/builtin-inject.c | 4 +--- tools/perf/util/annotate.c | 3 +-- tools/perf/util/dso.c | 7 ++++++- tools/perf/util/dso.h | 2 ++ tools/perf/util/dsos.c | 3 +-- tools/perf/util/symbol.c | 3 +-- 6 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c index 76723ac314b60b80..61766eead4f48e34 100644 --- a/tools/perf/builtin-inject.c +++ b/tools/perf/builtin-inject.c @@ -630,10 +630,8 @@ static int dso__read_build_id(struct dso *dso) if (filename__read_build_id(dso->long_name, &dso->bid) > 0) dso->has_build_id = true; else if (dso->nsinfo) { - char *new_name; + char *new_name = dso__filename_with_chroot(dso, dso->long_name); - new_name = filename_with_chroot(dso->nsinfo->pid, - dso->long_name); if (new_name && filename__read_build_id(new_name, &dso->bid) > 0) dso->has_build_id = true; free(new_name); diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c index e2693a1c28d5989f..ca9f0add68f461e4 100644 --- a/tools/perf/util/annotate.c +++ b/tools/perf/util/annotate.c @@ -1692,8 +1692,7 @@ static int dso__disassemble_filename(struct dso *dso, char *filename, size_t fil mutex_lock(&dso->lock); if (access(filename, R_OK) && errno == ENOENT && dso->nsinfo) { - char *new_name = filename_with_chroot(dso->nsinfo->pid, - filename); + char *new_name = dso__filename_with_chroot(dso, filename); if (new_name) { strlcpy(filename, new_name, filename_size); free(new_name); diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index e36b418df2c68cc2..0bc288f29a548dc9 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -491,6 +491,11 @@ static int do_open(char *name) return -1; } +char *dso__filename_with_chroot(const struct dso *dso, const char *filename) +{ + return filename_with_chroot(dso->nsinfo->pid, filename); +} + static int __open_dso(struct dso *dso, struct machine *machine) { int fd = -EINVAL; @@ -515,7 +520,7 @@ static int __open_dso(struct dso *dso, struct machine *machine) if (errno != ENOENT || dso->nsinfo == NULL) goto out; - new_name = filename_with_chroot(dso->nsinfo->pid, name); + new_name = dso__filename_with_chroot(dso, name); if (!new_name) goto out; diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h index 58d94175e7148049..0b7c7633b9f6667d 100644 --- a/tools/perf/util/dso.h +++ b/tools/perf/util/dso.h @@ -266,6 +266,8 @@ static inline bool dso__has_symbols(const struct dso *dso) return !RB_EMPTY_ROOT(&dso->symbols.rb_root); } +char *dso__filename_with_chroot(const struct dso *dso, const char *filename); + bool dso__sorted_by_name(const struct dso *dso); void dso__set_sorted_by_name(struct dso *dso); void dso__sort_by_name(struct dso *dso); diff --git a/tools/perf/util/dsos.c b/tools/perf/util/dsos.c index 2bd23e4cf19efaa7..cf80aa42dd07b036 100644 --- a/tools/perf/util/dsos.c +++ b/tools/perf/util/dsos.c @@ -91,8 +91,7 @@ bool __dsos__read_build_ids(struct list_head *head, bool with_hits) have_build_id = true; pos->has_build_id = true; } else if (errno == ENOENT && pos->nsinfo) { - char *new_name = filename_with_chroot(pos->nsinfo->pid, - pos->long_name); + char *new_name = dso__filename_with_chroot(pos, pos->long_name); if (new_name && filename__read_build_id(new_name, &pos->bid) > 0) { diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 91ebf93e0c20bd24..e7f63670688e8e59 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -1963,8 +1963,7 @@ int dso__load(struct dso *dso, struct map *map) is_reg = is_regular_file(name); if (!is_reg && errno == ENOENT && dso->nsinfo) { - char *new_name = filename_with_chroot(dso->nsinfo->pid, - name); + char *new_name = dso__filename_with_chroot(dso, name); if (new_name) { is_reg = is_regular_file(new_name); strlcpy(name, new_name, PATH_MAX); -- 2.39.2
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