diff options
Diffstat (limited to 'debian/patches/bugfix/all/tools-perf-pmu-events-fix-reproducibility.patch')
| -rw-r--r-- | debian/patches/bugfix/all/tools-perf-pmu-events-fix-reproducibility.patch | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/debian/patches/bugfix/all/tools-perf-pmu-events-fix-reproducibility.patch b/debian/patches/bugfix/all/tools-perf-pmu-events-fix-reproducibility.patch new file mode 100644 index 000000000..6da31fcd3 --- /dev/null +++ b/debian/patches/bugfix/all/tools-perf-pmu-events-fix-reproducibility.patch @@ -0,0 +1,175 @@ +From: Ben Hutchings <ben@decadent.org.uk> +Date: Sun, 25 Aug 2019 13:49:41 +0100 +Subject: tools/perf: pmu-events: Fix reproducibility +Forwarded: https://lore.kernel.org/lkml/20190825131329.naqzd5kwg7mw5d3f@decadent.org.uk/T/#u + +jevents.c uses nftw() to enumerate files and outputs the corresponding +C structs in the order they are found. This makes it sensitive to +directory ordering, so that the perf executable is not reproducible. + +To avoid this, store all the files and directories found and then sort +them by their (relative) path. (This maintains the parent-first +ordering that nftw() promises.) Then apply the existing callbacks to +them in the sorted order. + +Don't both storing the stat buffers as we don't need them. + +References: https://tests.reproducible-builds.org/debian/dbdtxt/bullseye/i386/linux_4.19.37-6.diffoscope.txt.gz +Signed-off-by: Ben Hutchings <ben@decadent.org.uk> +--- +--- a/tools/perf/pmu-events/jevents.c ++++ b/tools/perf/pmu-events/jevents.c +@@ -50,6 +50,18 @@ + #include "json.h" + #include "pmu-events.h" + ++struct ordered_ftw_entry { ++ const char *fpath; ++ int typeflag; ++ struct FTW ftwbuf; ++}; ++ ++struct ordered_ftw_state { ++ struct ordered_ftw_entry *entries; ++ size_t n; ++ size_t max; ++}; ++ + int verbose; + char *prog; + +@@ -905,6 +917,78 @@ static int get_maxfds(void) + */ + static FILE *eventsfp; + static char *mapfile; ++static struct ordered_ftw_state *ordered_ftw_state; ++ ++static int ordered_ftw_add(const char *fpath, const struct stat *sb, ++ int typeflag, struct FTW *ftwbuf) ++{ ++ struct ordered_ftw_state *state = ordered_ftw_state; ++ struct ordered_ftw_entry *entry; ++ ++ if (ftwbuf->level == 0 || ftwbuf->level > 3) ++ return 0; ++ ++ /* Grow array if necessary */ ++ if (state->n >= state->max) { ++ if (state->max == 0) ++ state->max = 16; ++ else ++ state->max *= 2; ++ state->entries = realloc(state->entries, ++ state->max * sizeof(*state->entries)); ++ } ++ ++ entry = &state->entries[state->n++]; ++ entry->fpath = strdup(fpath); ++ entry->typeflag = typeflag; ++ entry->ftwbuf = *ftwbuf; ++ ++ return 0; ++} ++ ++static int ordered_ftw_compare(const void *left, const void *right) ++{ ++ const struct ordered_ftw_entry *left_entry = left; ++ const struct ordered_ftw_entry *right_entry = right; ++ ++ return strcmp(left_entry->fpath, right_entry->fpath); ++} ++ ++/* ++ * Wrapper for nftw() that iterates files in ASCII-order to ensure ++ * reproducible output ++ */ ++static int ordered_ftw(const char *dirpath, ++ int (*fn)(const char *, int, struct FTW *), ++ int nopenfd) ++{ ++ struct ordered_ftw_state state = { NULL, 0, 0 }; ++ size_t i; ++ int rc; ++ ++ ordered_ftw_state = &state; ++ rc = nftw(dirpath, ordered_ftw_add, nopenfd, 0); ++ if (rc) ++ goto out; ++ ++ qsort(state.entries, state.n, sizeof(*state.entries), ++ ordered_ftw_compare); ++ ++ for (i = 0; i < state.n; i++) { ++ rc = fn(state.entries[i].fpath, ++ state.entries[i].typeflag, ++ &state.entries[i].ftwbuf); ++ if (rc) ++ goto out; ++ } ++ ++out: ++ for (i = 0; i < state.n; i++) ++ free((char *)state.entries[i].fpath); ++ free(state.entries);; ++ ++ return rc; ++} + + static int is_leaf_dir(const char *fpath) + { +@@ -957,19 +1041,19 @@ static int is_json_file(const char *name + return 0; + } + +-static int preprocess_arch_std_files(const char *fpath, const struct stat *sb, ++static int preprocess_arch_std_files(const char *fpath, + int typeflag, struct FTW *ftwbuf) + { + int level = ftwbuf->level; + int is_file = typeflag == FTW_F; + + if (level == 1 && is_file && is_json_file(fpath)) +- return json_events(fpath, save_arch_std_events, (void *)sb); ++ return json_events(fpath, save_arch_std_events, NULL); + + return 0; + } + +-static int process_one_file(const char *fpath, const struct stat *sb, ++static int process_one_file(const char *fpath, + int typeflag, struct FTW *ftwbuf) + { + char *tblname, *bname; +@@ -994,9 +1078,9 @@ static int process_one_file(const char * + } else + bname = (char *) fpath + ftwbuf->base; + +- pr_debug("%s %d %7jd %-20s %s\n", ++ pr_debug("%s %d %-20s %s\n", + is_file ? "f" : is_dir ? "d" : "x", +- level, sb->st_size, bname, fpath); ++ level, bname, fpath); + + /* base dir or too deep */ + if (level == 0 || level > 3) +@@ -1152,17 +1236,17 @@ int main(int argc, char *argv[]) + */ + + maxfds = get_maxfds(); +- rc = nftw(ldirname, preprocess_arch_std_files, maxfds, 0); ++ rc = ordered_ftw(ldirname, preprocess_arch_std_files, maxfds); + if (rc) + goto err_processing_std_arch_event_dir; + +- rc = nftw(ldirname, process_one_file, maxfds, 0); ++ rc = ordered_ftw(ldirname, process_one_file, maxfds); + if (rc) + goto err_processing_dir; + + sprintf(ldirname, "%s/test", start_dirname); + +- rc = nftw(ldirname, process_one_file, maxfds, 0); ++ rc = ordered_ftw(ldirname, process_one_file, maxfds); + if (rc) + goto err_processing_dir; + |