This is a note to let you know that I've just added the patch titled perf bench inject-buildid: Handle writen() errors to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: perf-bench-inject-buildid-handle-writen-errors.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit ea2d439cc4a9d28390bc167d15c3243da538e27b Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Date: Wed Aug 25 11:50:37 2021 -0300 perf bench inject-buildid: Handle writen() errors [ Upstream commit edf7b4a2d85e37a1ee77156bddaed4aa6af9c5e1 ] The build on fedora:35 and fedora:rawhide with clang is failing with: 49 41.00 fedora:35 : FAIL clang version 13.0.0 (Fedora 13.0.0~rc1-1.fc35) bench/inject-buildid.c:351:6: error: variable 'len' set but not used [-Werror,-Wunused-but-set-variable] u64 len = 0; ^ 1 error generated. make[3]: *** [/git/perf-5.14.0-rc7/tools/build/Makefile.build:139: bench] Error 2 50 41.11 fedora:rawhide : FAIL clang version 13.0.0 (Fedora 13.0.0~rc1-1.fc35) bench/inject-buildid.c:351:6: error: variable 'len' set but not used [-Werror,-Wunused-but-set-variable] u64 len = 0; ^ 1 error generated. make[3]: *** [/git/perf-5.14.0-rc7/tools/build/Makefile.build:139: bench] Error 2 That 'len' variable is not used at all, so just make sure all the synthesize_RECORD() routines return ssize_t to propagate the writen() return, as it may fail, ditch the 'ret' var and bail out if those routines fail. Fixes: 0bf02a0d80427f26 ("perf bench: Add build-id injection benchmark") Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx> Link: http://lore.kernel.org/lkml/CAM9d7cgEZNSor+B+7Y2C+QYGme_v5aH0Zn0RLfxoQ+Fy83EHrg@xxxxxxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/perf/bench/inject-buildid.c b/tools/perf/bench/inject-buildid.c index 280227e3ffd7..f4ec01da8da6 100644 --- a/tools/perf/bench/inject-buildid.c +++ b/tools/perf/bench/inject-buildid.c @@ -133,7 +133,7 @@ static u64 dso_map_addr(struct bench_dso *dso) return 0x400000ULL + dso->ino * 8192ULL; } -static u32 synthesize_attr(struct bench_data *data) +static ssize_t synthesize_attr(struct bench_data *data) { union perf_event event; @@ -151,7 +151,7 @@ static u32 synthesize_attr(struct bench_data *data) return writen(data->input_pipe[1], &event, event.header.size); } -static u32 synthesize_fork(struct bench_data *data) +static ssize_t synthesize_fork(struct bench_data *data) { union perf_event event; @@ -169,8 +169,7 @@ static u32 synthesize_fork(struct bench_data *data) return writen(data->input_pipe[1], &event, event.header.size); } -static u32 synthesize_mmap(struct bench_data *data, struct bench_dso *dso, - u64 timestamp) +static ssize_t synthesize_mmap(struct bench_data *data, struct bench_dso *dso, u64 timestamp) { union perf_event event; size_t len = offsetof(struct perf_record_mmap2, filename); @@ -198,23 +197,25 @@ static u32 synthesize_mmap(struct bench_data *data, struct bench_dso *dso, if (len > sizeof(event.mmap2)) { /* write mmap2 event first */ - writen(data->input_pipe[1], &event, len - bench_id_hdr_size); + if (writen(data->input_pipe[1], &event, len - bench_id_hdr_size) < 0) + return -1; /* zero-fill sample id header */ memset(id_hdr_ptr, 0, bench_id_hdr_size); /* put timestamp in the right position */ ts_idx = (bench_id_hdr_size / sizeof(u64)) - 2; id_hdr_ptr[ts_idx] = timestamp; - writen(data->input_pipe[1], id_hdr_ptr, bench_id_hdr_size); - } else { - ts_idx = (len / sizeof(u64)) - 2; - id_hdr_ptr[ts_idx] = timestamp; - writen(data->input_pipe[1], &event, len); + if (writen(data->input_pipe[1], id_hdr_ptr, bench_id_hdr_size) < 0) + return -1; + + return len; } - return len; + + ts_idx = (len / sizeof(u64)) - 2; + id_hdr_ptr[ts_idx] = timestamp; + return writen(data->input_pipe[1], &event, len); } -static u32 synthesize_sample(struct bench_data *data, struct bench_dso *dso, - u64 timestamp) +static ssize_t synthesize_sample(struct bench_data *data, struct bench_dso *dso, u64 timestamp) { union perf_event event; struct perf_sample sample = { @@ -233,7 +234,7 @@ static u32 synthesize_sample(struct bench_data *data, struct bench_dso *dso, return writen(data->input_pipe[1], &event, event.header.size); } -static u32 synthesize_flush(struct bench_data *data) +static ssize_t synthesize_flush(struct bench_data *data) { struct perf_event_header header = { .size = sizeof(header), @@ -348,14 +349,16 @@ static int inject_build_id(struct bench_data *data, u64 *max_rss) int status; unsigned int i, k; struct rusage rusage; - u64 len = 0; /* this makes the child to run */ if (perf_header__write_pipe(data->input_pipe[1]) < 0) return -1; - len += synthesize_attr(data); - len += synthesize_fork(data); + if (synthesize_attr(data) < 0) + return -1; + + if (synthesize_fork(data) < 0) + return -1; for (i = 0; i < nr_mmaps; i++) { int idx = rand() % (nr_dsos - 1); @@ -363,13 +366,18 @@ static int inject_build_id(struct bench_data *data, u64 *max_rss) u64 timestamp = rand() % 1000000; pr_debug2(" [%d] injecting: %s\n", i+1, dso->name); - len += synthesize_mmap(data, dso, timestamp); + if (synthesize_mmap(data, dso, timestamp) < 0) + return -1; - for (k = 0; k < nr_samples; k++) - len += synthesize_sample(data, dso, timestamp + k * 1000); + for (k = 0; k < nr_samples; k++) { + if (synthesize_sample(data, dso, timestamp + k * 1000) < 0) + return -1; + } - if ((i + 1) % 10 == 0) - len += synthesize_flush(data); + if ((i + 1) % 10 == 0) { + if (synthesize_flush(data) < 0) + return -1; + } } /* tihs makes the child to finish */