| Message ID | 20230608232823.4027869-27-irogers@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix memory leaks (was reference count checking for thread) | expand |
Em Thu, Jun 08, 2023 at 04:28:23PM -0700, Ian Rogers escreveu: > srcline isn't freed if it is SRCLINE_UNKNOWN. Avoid strduping in this > case as such strdups are redundant and leak memory. The patch is ok as its what the rest of the code is doing, i.e. strcmp() to check if a srcline is the unknown one, but how about the following patch on top of yours? From 5163e54c1ed3d476f6b4e7f938861039bd4eec7c Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo <acme@redhat.com> Date: Mon, 12 Jun 2023 11:10:46 -0300 Subject: [PATCH 1/1] perf srcline: Optimize comparision against SRCLINE_UNKNOWN This is a string constant that gets returned and then strcmp() around, we can instead just do a pointer comparision. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/lkml/ Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/builtin-diff.c | 4 ++-- tools/perf/util/block-info.c | 4 ++-- tools/perf/util/hist.c | 2 +- tools/perf/util/map.c | 2 +- tools/perf/util/sort.c | 2 +- tools/perf/util/srcline.c | 2 +- 6 files changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c index eec89567ae483604..e8a1b16aa5f83f4f 100644 --- a/tools/perf/builtin-diff.c +++ b/tools/perf/builtin-diff.c @@ -1378,8 +1378,8 @@ static int cycles_printf(struct hist_entry *he, struct hist_entry *pair, end_line = map__srcline(he->ms.map, bi->sym->start + bi->end, he->ms.sym); - if ((strncmp(start_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) && - (strncmp(end_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)) { + if (start_line != SRCLINE_UNKNOWN && + end_line != SRCLINE_UNKNOWN) { scnprintf(buf, sizeof(buf), "[%s -> %s] %4ld", start_line, end_line, block_he->diff.cycles); } else { diff --git a/tools/perf/util/block-info.c b/tools/perf/util/block-info.c index 08279b1b65e5a4b0..fe4c17248799f0a2 100644 --- a/tools/perf/util/block-info.c +++ b/tools/perf/util/block-info.c @@ -296,8 +296,8 @@ static int block_range_entry(struct perf_hpp_fmt *fmt, struct perf_hpp *hpp, end_line = map__srcline(he->ms.map, bi->sym->start + bi->end, he->ms.sym); - if ((strncmp(start_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) && - (strncmp(end_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)) { + if (start_line != SRCLINE_UNKNOWN) && + end_line != SRCLINE_UNKNOWN) { scnprintf(buf, sizeof(buf), "[%s -> %s]", start_line, end_line); } else { diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c index 0a10bcc6ec95b5e0..3dc8a4968beb9c01 100644 --- a/tools/perf/util/hist.c +++ b/tools/perf/util/hist.c @@ -484,7 +484,7 @@ static int hist_entry__init(struct hist_entry *he, goto err_infos; } - if (he->srcline && strcmp(he->srcline, SRCLINE_UNKNOWN)) { + if (he->srcline && he->srcline != SRCLINE_UNKNOWN) { he->srcline = strdup(he->srcline); if (he->srcline == NULL) goto err_rawdata; diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c index c77e2fce6a379e7f..f30d34903aa4eabe 100644 --- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -496,7 +496,7 @@ int map__fprintf_srcline(struct map *map, u64 addr, const char *prefix, if (dso) { char *srcline = map__srcline(map, addr, NULL); - if (strncmp(srcline, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) + if (srcline != SRCLINE_UNKNOWN) ret = fprintf(fp, "%s%s", prefix, srcline); zfree_srcline(&srcline); } diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c index 047c3606802f5b7f..6aa1c7f2b4448b30 100644 --- a/tools/perf/util/sort.c +++ b/tools/perf/util/sort.c @@ -643,7 +643,7 @@ static char *hist_entry__get_srcfile(struct hist_entry *e) sf = __get_srcline(map__dso(map), map__rip_2objdump(map, e->ip), e->ms.sym, false, true, true, e->ip); - if (!strcmp(sf, SRCLINE_UNKNOWN)) + if (sf == SRCLINE_UNKNOWN) return no_srcfile; p = strchr(sf, ':'); if (p && *sf) { diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c index b8e596528d7e7e5e..48a04f42b308b080 100644 --- a/tools/perf/util/srcline.c +++ b/tools/perf/util/srcline.c @@ -809,7 +809,7 @@ void zfree_srcline(char **srcline) if (*srcline == NULL) return; - if (strcmp(*srcline, SRCLINE_UNKNOWN)) + if (*srcline != SRCLINE_UNKNOWN) free(*srcline); *srcline = NULL;
Em Mon, Jun 12, 2023 at 11:13:59AM -0300, Arnaldo Carvalho de Melo escreveu: > Em Thu, Jun 08, 2023 at 04:28:23PM -0700, Ian Rogers escreveu: > > srcline isn't freed if it is SRCLINE_UNKNOWN. Avoid strduping in this > > case as such strdups are redundant and leak memory. > > The patch is ok as its what the rest of the code is doing, i.e. strcmp() > to check if a srcline is the unknown one, but how about the following > patch on top of yours? [acme@quaco perf-tools-next]$ strings ~/bin/perf | grep '??:0' ??:0 SRCLINE_UNKNOWN ((char *) "??:0") [acme@quaco perf-tools-next]$ > From 5163e54c1ed3d476f6b4e7f938861039bd4eec7c Mon Sep 17 00:00:00 2001 > From: Arnaldo Carvalho de Melo <acme@redhat.com> > Date: Mon, 12 Jun 2023 11:10:46 -0300 > Subject: [PATCH 1/1] perf srcline: Optimize comparision against > SRCLINE_UNKNOWN > > This is a string constant that gets returned and then strcmp() around, > we can instead just do a pointer comparision. > > Cc: Adrian Hunter <adrian.hunter@intel.com> > Cc: Ian Rogers <irogers@google.com> > Cc: Jiri Olsa <jolsa@kernel.org> > Cc: Namhyung Kim <namhyung@kernel.org> > Link: https://lore.kernel.org/lkml/ > Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> > --- > tools/perf/builtin-diff.c | 4 ++-- > tools/perf/util/block-info.c | 4 ++-- > tools/perf/util/hist.c | 2 +- > tools/perf/util/map.c | 2 +- > tools/perf/util/sort.c | 2 +- > tools/perf/util/srcline.c | 2 +- > 6 files changed, 8 insertions(+), 8 deletions(-) > > diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c > index eec89567ae483604..e8a1b16aa5f83f4f 100644 > --- a/tools/perf/builtin-diff.c > +++ b/tools/perf/builtin-diff.c > @@ -1378,8 +1378,8 @@ static int cycles_printf(struct hist_entry *he, struct hist_entry *pair, > end_line = map__srcline(he->ms.map, bi->sym->start + bi->end, > he->ms.sym); > > - if ((strncmp(start_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) && > - (strncmp(end_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)) { > + if (start_line != SRCLINE_UNKNOWN && > + end_line != SRCLINE_UNKNOWN) { > scnprintf(buf, sizeof(buf), "[%s -> %s] %4ld", > start_line, end_line, block_he->diff.cycles); > } else { > diff --git a/tools/perf/util/block-info.c b/tools/perf/util/block-info.c > index 08279b1b65e5a4b0..fe4c17248799f0a2 100644 > --- a/tools/perf/util/block-info.c > +++ b/tools/perf/util/block-info.c > @@ -296,8 +296,8 @@ static int block_range_entry(struct perf_hpp_fmt *fmt, struct perf_hpp *hpp, > end_line = map__srcline(he->ms.map, bi->sym->start + bi->end, > he->ms.sym); > > - if ((strncmp(start_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) && > - (strncmp(end_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)) { > + if (start_line != SRCLINE_UNKNOWN) && > + end_line != SRCLINE_UNKNOWN) { > scnprintf(buf, sizeof(buf), "[%s -> %s]", > start_line, end_line); > } else { > diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c > index 0a10bcc6ec95b5e0..3dc8a4968beb9c01 100644 > --- a/tools/perf/util/hist.c > +++ b/tools/perf/util/hist.c > @@ -484,7 +484,7 @@ static int hist_entry__init(struct hist_entry *he, > goto err_infos; > } > > - if (he->srcline && strcmp(he->srcline, SRCLINE_UNKNOWN)) { > + if (he->srcline && he->srcline != SRCLINE_UNKNOWN) { > he->srcline = strdup(he->srcline); > if (he->srcline == NULL) > goto err_rawdata; > diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c > index c77e2fce6a379e7f..f30d34903aa4eabe 100644 > --- a/tools/perf/util/map.c > +++ b/tools/perf/util/map.c > @@ -496,7 +496,7 @@ int map__fprintf_srcline(struct map *map, u64 addr, const char *prefix, > > if (dso) { > char *srcline = map__srcline(map, addr, NULL); > - if (strncmp(srcline, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) > + if (srcline != SRCLINE_UNKNOWN) > ret = fprintf(fp, "%s%s", prefix, srcline); > zfree_srcline(&srcline); > } > diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c > index 047c3606802f5b7f..6aa1c7f2b4448b30 100644 > --- a/tools/perf/util/sort.c > +++ b/tools/perf/util/sort.c > @@ -643,7 +643,7 @@ static char *hist_entry__get_srcfile(struct hist_entry *e) > > sf = __get_srcline(map__dso(map), map__rip_2objdump(map, e->ip), > e->ms.sym, false, true, true, e->ip); > - if (!strcmp(sf, SRCLINE_UNKNOWN)) > + if (sf == SRCLINE_UNKNOWN) > return no_srcfile; > p = strchr(sf, ':'); > if (p && *sf) { > diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c > index b8e596528d7e7e5e..48a04f42b308b080 100644 > --- a/tools/perf/util/srcline.c > +++ b/tools/perf/util/srcline.c > @@ -809,7 +809,7 @@ void zfree_srcline(char **srcline) > if (*srcline == NULL) > return; > > - if (strcmp(*srcline, SRCLINE_UNKNOWN)) > + if (*srcline != SRCLINE_UNKNOWN) > free(*srcline); > > *srcline = NULL; > -- > 2.39.2 > > > > Signed-off-by: Ian Rogers <irogers@google.com> > > --- > > tools/perf/util/hist.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c > > index 77cb2cc83bb9..cc6f7f51faa5 100644 > > --- a/tools/perf/util/hist.c > > +++ b/tools/perf/util/hist.c > > @@ -484,7 +484,7 @@ static int hist_entry__init(struct hist_entry *he, > > goto err_infos; > > } > > > > - if (he->srcline) { > > + if (he->srcline && strcmp(he->srcline, SRCLINE_UNKNOWN)) { > > he->srcline = strdup(he->srcline); > > if (he->srcline == NULL) > > goto err_rawdata; > > -- > > 2.41.0.162.gfafddb0af9-goog > > > > -- > > - Arnaldo
On Mon, Jun 12, 2023 at 7:16 AM Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > Em Mon, Jun 12, 2023 at 11:13:59AM -0300, Arnaldo Carvalho de Melo escreveu: > > Em Thu, Jun 08, 2023 at 04:28:23PM -0700, Ian Rogers escreveu: > > > srcline isn't freed if it is SRCLINE_UNKNOWN. Avoid strduping in this > > > case as such strdups are redundant and leak memory. > > > > The patch is ok as its what the rest of the code is doing, i.e. strcmp() > > to check if a srcline is the unknown one, but how about the following > > patch on top of yours? > > [acme@quaco perf-tools-next]$ strings ~/bin/perf | grep '??:0' > ??:0 > SRCLINE_UNKNOWN ((char *) "??:0") > [acme@quaco perf-tools-next]$ Agreed, the strcmps make me nervous as they won't distinguish heap from a global meaning we could end up with things like pointers to freed memory. The comparison with the global is always going to be same imo. Acked-by: Ian Rogers <irogers@google.com> Thanks, Ian > > From 5163e54c1ed3d476f6b4e7f938861039bd4eec7c Mon Sep 17 00:00:00 2001 > > From: Arnaldo Carvalho de Melo <acme@redhat.com> > > Date: Mon, 12 Jun 2023 11:10:46 -0300 > > Subject: [PATCH 1/1] perf srcline: Optimize comparision against > > SRCLINE_UNKNOWN > > > > This is a string constant that gets returned and then strcmp() around, > > we can instead just do a pointer comparision. > > > > Cc: Adrian Hunter <adrian.hunter@intel.com> > > Cc: Ian Rogers <irogers@google.com> > > Cc: Jiri Olsa <jolsa@kernel.org> > > Cc: Namhyung Kim <namhyung@kernel.org> > > Link: https://lore.kernel.org/lkml/ > > Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> > > --- > > tools/perf/builtin-diff.c | 4 ++-- > > tools/perf/util/block-info.c | 4 ++-- > > tools/perf/util/hist.c | 2 +- > > tools/perf/util/map.c | 2 +- > > tools/perf/util/sort.c | 2 +- > > tools/perf/util/srcline.c | 2 +- > > 6 files changed, 8 insertions(+), 8 deletions(-) > > > > diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c > > index eec89567ae483604..e8a1b16aa5f83f4f 100644 > > --- a/tools/perf/builtin-diff.c > > +++ b/tools/perf/builtin-diff.c > > @@ -1378,8 +1378,8 @@ static int cycles_printf(struct hist_entry *he, struct hist_entry *pair, > > end_line = map__srcline(he->ms.map, bi->sym->start + bi->end, > > he->ms.sym); > > > > - if ((strncmp(start_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) && > > - (strncmp(end_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)) { > > + if (start_line != SRCLINE_UNKNOWN && > > + end_line != SRCLINE_UNKNOWN) { > > scnprintf(buf, sizeof(buf), "[%s -> %s] %4ld", > > start_line, end_line, block_he->diff.cycles); > > } else { > > diff --git a/tools/perf/util/block-info.c b/tools/perf/util/block-info.c > > index 08279b1b65e5a4b0..fe4c17248799f0a2 100644 > > --- a/tools/perf/util/block-info.c > > +++ b/tools/perf/util/block-info.c > > @@ -296,8 +296,8 @@ static int block_range_entry(struct perf_hpp_fmt *fmt, struct perf_hpp *hpp, > > end_line = map__srcline(he->ms.map, bi->sym->start + bi->end, > > he->ms.sym); > > > > - if ((strncmp(start_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) && > > - (strncmp(end_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)) { > > + if (start_line != SRCLINE_UNKNOWN) && > > + end_line != SRCLINE_UNKNOWN) { > > scnprintf(buf, sizeof(buf), "[%s -> %s]", > > start_line, end_line); > > } else { > > diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c > > index 0a10bcc6ec95b5e0..3dc8a4968beb9c01 100644 > > --- a/tools/perf/util/hist.c > > +++ b/tools/perf/util/hist.c > > @@ -484,7 +484,7 @@ static int hist_entry__init(struct hist_entry *he, > > goto err_infos; > > } > > > > - if (he->srcline && strcmp(he->srcline, SRCLINE_UNKNOWN)) { > > + if (he->srcline && he->srcline != SRCLINE_UNKNOWN) { > > he->srcline = strdup(he->srcline); > > if (he->srcline == NULL) > > goto err_rawdata; > > diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c > > index c77e2fce6a379e7f..f30d34903aa4eabe 100644 > > --- a/tools/perf/util/map.c > > +++ b/tools/perf/util/map.c > > @@ -496,7 +496,7 @@ int map__fprintf_srcline(struct map *map, u64 addr, const char *prefix, > > > > if (dso) { > > char *srcline = map__srcline(map, addr, NULL); > > - if (strncmp(srcline, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) > > + if (srcline != SRCLINE_UNKNOWN) > > ret = fprintf(fp, "%s%s", prefix, srcline); > > zfree_srcline(&srcline); > > } > > diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c > > index 047c3606802f5b7f..6aa1c7f2b4448b30 100644 > > --- a/tools/perf/util/sort.c > > +++ b/tools/perf/util/sort.c > > @@ -643,7 +643,7 @@ static char *hist_entry__get_srcfile(struct hist_entry *e) > > > > sf = __get_srcline(map__dso(map), map__rip_2objdump(map, e->ip), > > e->ms.sym, false, true, true, e->ip); > > - if (!strcmp(sf, SRCLINE_UNKNOWN)) > > + if (sf == SRCLINE_UNKNOWN) > > return no_srcfile; > > p = strchr(sf, ':'); > > if (p && *sf) { > > diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c > > index b8e596528d7e7e5e..48a04f42b308b080 100644 > > --- a/tools/perf/util/srcline.c > > +++ b/tools/perf/util/srcline.c > > @@ -809,7 +809,7 @@ void zfree_srcline(char **srcline) > > if (*srcline == NULL) > > return; > > > > - if (strcmp(*srcline, SRCLINE_UNKNOWN)) > > + if (*srcline != SRCLINE_UNKNOWN) > > free(*srcline); > > > > *srcline = NULL; > > -- > > 2.39.2 > > > > > > > Signed-off-by: Ian Rogers <irogers@google.com> > > > --- > > > tools/perf/util/hist.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c > > > index 77cb2cc83bb9..cc6f7f51faa5 100644 > > > --- a/tools/perf/util/hist.c > > > +++ b/tools/perf/util/hist.c > > > @@ -484,7 +484,7 @@ static int hist_entry__init(struct hist_entry *he, > > > goto err_infos; > > > } > > > > > > - if (he->srcline) { > > > + if (he->srcline && strcmp(he->srcline, SRCLINE_UNKNOWN)) { > > > he->srcline = strdup(he->srcline); > > > if (he->srcline == NULL) > > > goto err_rawdata; > > > -- > > > 2.41.0.162.gfafddb0af9-goog > > > > > > > -- > > > > - Arnaldo > > -- > > - Arnaldo
Em Mon, Jun 12, 2023 at 07:46:14AM -0700, Ian Rogers escreveu: > On Mon, Jun 12, 2023 at 7:16 AM Arnaldo Carvalho de Melo > <acme@kernel.org> wrote: > > > > Em Mon, Jun 12, 2023 at 11:13:59AM -0300, Arnaldo Carvalho de Melo escreveu: > > > Em Thu, Jun 08, 2023 at 04:28:23PM -0700, Ian Rogers escreveu: > > > > srcline isn't freed if it is SRCLINE_UNKNOWN. Avoid strduping in this > > > > case as such strdups are redundant and leak memory. > > > > > > The patch is ok as its what the rest of the code is doing, i.e. strcmp() > > > to check if a srcline is the unknown one, but how about the following > > > patch on top of yours? > > > > [acme@quaco perf-tools-next]$ strings ~/bin/perf | grep '??:0' > > ??:0 > > SRCLINE_UNKNOWN ((char *) "??:0") > > [acme@quaco perf-tools-next]$ > > Agreed, the strcmps make me nervous as they won't distinguish heap > from a global meaning we could end up with things like pointers to > freed memory. The comparison with the global is always going to be > same imo. > > Acked-by: Ian Rogers <irogers@google.com> Thanks, applied and added your Acked-by. - Arnaldo
On Mon, Jun 12, 2023 at 02:23:41PM -0300, Arnaldo Carvalho de Melo wrote: > Em Mon, Jun 12, 2023 at 07:46:14AM -0700, Ian Rogers escreveu: > > On Mon, Jun 12, 2023 at 7:16 AM Arnaldo Carvalho de Melo > > <acme@kernel.org> wrote: > > > > > > Em Mon, Jun 12, 2023 at 11:13:59AM -0300, Arnaldo Carvalho de Melo escreveu: > > > > Em Thu, Jun 08, 2023 at 04:28:23PM -0700, Ian Rogers escreveu: > > > > > srcline isn't freed if it is SRCLINE_UNKNOWN. Avoid strduping in this > > > > > case as such strdups are redundant and leak memory. > > > > > > > > The patch is ok as its what the rest of the code is doing, i.e. strcmp() > > > > to check if a srcline is the unknown one, but how about the following > > > > patch on top of yours? > > > > > > [acme@quaco perf-tools-next]$ strings ~/bin/perf | grep '??:0' > > > ??:0 > > > SRCLINE_UNKNOWN ((char *) "??:0") > > > [acme@quaco perf-tools-next]$ > > > > Agreed, the strcmps make me nervous as they won't distinguish heap > > from a global meaning we could end up with things like pointers to > > freed memory. The comparison with the global is always going to be > > same imo. > > > > Acked-by: Ian Rogers <irogers@google.com> > > Thanks, applied and added your Acked-by. Actually was there another patch that turned it into a explicit global? At least in my tree it isn't: util/srcline.h 28:#define SRCLINE_UNKNOWN ((char *) "??:0") Without any explicit global it's a bit dangerous because you rely on the linker doing string deduplication. While it normally does that there might be odd corner cases where it doesn't. -Andi
Em Mon, Jun 12, 2023 at 02:16:34PM -0700, Andi Kleen escreveu: > On Mon, Jun 12, 2023 at 02:23:41PM -0300, Arnaldo Carvalho de Melo wrote: > > Em Mon, Jun 12, 2023 at 07:46:14AM -0700, Ian Rogers escreveu: > > > On Mon, Jun 12, 2023 at 7:16 AM Arnaldo Carvalho de Melo > > > <acme@kernel.org> wrote: > > > > > > > > Em Mon, Jun 12, 2023 at 11:13:59AM -0300, Arnaldo Carvalho de Melo escreveu: > > > > > Em Thu, Jun 08, 2023 at 04:28:23PM -0700, Ian Rogers escreveu: > > > > > > srcline isn't freed if it is SRCLINE_UNKNOWN. Avoid strduping in this > > > > > > case as such strdups are redundant and leak memory. > > > > > > > > > > The patch is ok as its what the rest of the code is doing, i.e. strcmp() > > > > > to check if a srcline is the unknown one, but how about the following > > > > > patch on top of yours? > > > > > > > > [acme@quaco perf-tools-next]$ strings ~/bin/perf | grep '??:0' > > > > ??:0 > > > > SRCLINE_UNKNOWN ((char *) "??:0") > > > > [acme@quaco perf-tools-next]$ > > > > > > Agreed, the strcmps make me nervous as they won't distinguish heap > > > from a global meaning we could end up with things like pointers to > > > freed memory. The comparison with the global is always going to be > > > same imo. > > > > > > Acked-by: Ian Rogers <irogers@google.com> > > > > Thanks, applied and added your Acked-by. > > Actually was there another patch that turned it into a explicit global? > > At least in my tree it isn't: > > util/srcline.h > 28:#define SRCLINE_UNKNOWN ((char *) "??:0") > > Without any explicit global it's a bit dangerous because you rely on the > linker doing string deduplication. While it normally does that there might be > odd corner cases where it doesn't. Yeah, several gcc and clang versions complained with: 2 65.38 almalinux:9 : FAIL clang version 15.0.7 (Red Hat 15.0.7-2.el9) builtin-diff.c:1381:17: error: result of comparison against a string literal is unspecified (use an explicit string comparison function instead) [-Werror,-Wstring-compare] if (start_line != SRCLINE_UNKNOWN && So I added the following on top: diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c index 48a04f42b308b080..aec596a0b0bbec0f 100644 --- a/tools/perf/util/srcline.c +++ b/tools/perf/util/srcline.c @@ -23,6 +23,8 @@ bool srcline_full_filename; +char *srcline__unknown = (char *)"??:0"; + static const char *dso__name(struct dso *dso) { const char *dso_name; diff --git a/tools/perf/util/srcline.h b/tools/perf/util/srcline.h index a15c7db9058ece96..167645bcff0755e2 100644 --- a/tools/perf/util/srcline.h +++ b/tools/perf/util/srcline.h @@ -25,7 +25,8 @@ char *srcline__tree_find(struct rb_root_cached *tree, u64 addr); /* delete all srclines within the tree */ void srcline__tree_delete(struct rb_root_cached *tree); -#define SRCLINE_UNKNOWN ((char *) "??:0") +extern char *srcline__unknown; +#define SRCLINE_UNKNOWN srcline__unknown struct inline_list { struct symbol *symbol;
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c index 77cb2cc83bb9..cc6f7f51faa5 100644 --- a/tools/perf/util/hist.c +++ b/tools/perf/util/hist.c @@ -484,7 +484,7 @@ static int hist_entry__init(struct hist_entry *he, goto err_infos; } - if (he->srcline) { + if (he->srcline && strcmp(he->srcline, SRCLINE_UNKNOWN)) { he->srcline = strdup(he->srcline); if (he->srcline == NULL) goto err_rawdata;
srcline isn't freed if it is SRCLINE_UNKNOWN. Avoid strduping in this case as such strdups are redundant and leak memory. Signed-off-by: Ian Rogers <irogers@google.com> --- tools/perf/util/hist.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)