perf bench inject-buildid: Handle writen() errors

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@kernel.org>
Link: http://lore.kernel.org/lkml/CAM9d7cgEZNSor+B+7Y2C+QYGme_v5aH0Zn0RLfxoQ+Fy83EHrg@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/bench/inject-buildid.c b/tools/perf/bench/inject-buildid.c
index 55d373b..1767279 100644 (file)
--- 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;
 }
 
        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;
 
 {
        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);
 }
 
        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;
 
 {
        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);
 }
 
        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);
 {
        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 */
 
        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;
                /* 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 = {
 {
        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);
 }
 
        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),
 {
        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;
        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;
 
 
        /* 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);
 
        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);
                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;
+               }

        }
 
        /* this makes the child to finish */
        }
 
        /* this makes the child to finish */