Use new read/write locks when accesing buildid directory on places where we may race if multiple instances are run simultaneously.
Signed-off-by: Milos Vyletel <[email protected]> --- tools/perf/builtin-buildid-cache.c | 12 +++++++++++ tools/perf/util/build-id.c | 41 ++++++++++++++++++++++++++++++-------- 2 files changed, 45 insertions(+), 8 deletions(-) diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c index d47a0cd..4cf0a1d 100644 --- a/tools/perf/builtin-buildid-cache.c +++ b/tools/perf/builtin-buildid-cache.c @@ -94,8 +94,13 @@ static int build_id_cache__kcore_existing(const char *from_dir, char *to_dir, char to_subdir[PATH_MAX]; struct dirent *dent; int ret = -1; + int lockfd; DIR *d; + buildid_dir_read_lock(&lockfd); + if (lockfd == -1) + return -1; + d = opendir(to_dir); if (!d) return -1; @@ -121,6 +126,7 @@ static int build_id_cache__kcore_existing(const char *from_dir, char *to_dir, } closedir(d); + buildid_dir_read_unlock(lockfd); return ret; } @@ -130,6 +136,7 @@ static int build_id_cache__add_kcore(const char *filename, bool force) char dir[32], sbuildid[BUILD_ID_SIZE * 2 + 1]; char from_dir[PATH_MAX], to_dir[PATH_MAX]; char *p; + int lockfd; strlcpy(from_dir, filename, sizeof(from_dir)); @@ -156,6 +163,10 @@ static int build_id_cache__add_kcore(const char *filename, bool force) scnprintf(to_dir, sizeof(to_dir), "%s/[kernel.kcore]/%s/%s", buildid_dir, sbuildid, dir); + buildid_dir_write_lock(&lockfd); + if (lockfd == -1) + return -1; + if (mkdir_p(to_dir, 0755)) return -1; @@ -176,6 +187,7 @@ static int build_id_cache__add_kcore(const char *filename, bool force) } return -1; } + buildid_dir_write_unlock(lockfd); pr_debug("kcore added to build-id cache directory %s\n", to_dir); diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c index 46c41e1..13d23aa 100644 --- a/tools/perf/util/build-id.c +++ b/tools/perf/util/build-id.c @@ -17,6 +17,7 @@ #include "tool.h" #include "header.h" #include "vdso.h" +#include <sys/file.h> static bool no_buildid_cache; @@ -308,6 +309,7 @@ int build_id_cache__list_build_ids(const char *pathname, DIR *dir; struct dirent *d; int ret = 0; + int lockfd = -1; list = strlist__new(true, NULL); dir_name = build_id_cache__dirname_from_path(pathname, false, false); @@ -316,11 +318,17 @@ int build_id_cache__list_build_ids(const char *pathname, goto out; } + buildid_dir_read_lock(&lockfd); + if (lockfd == -1) { + ret = -errno; + goto out; + } + /* List up all dirents */ dir = opendir(dir_name); if (!dir) { ret = -errno; - goto out; + goto out_unlock; } while ((d = readdir(dir)) != NULL) { @@ -330,6 +338,8 @@ int build_id_cache__list_build_ids(const char *pathname, } closedir(dir); +out_unlock: + buildid_dir_read_unlock(lockfd); out: free(dir_name); if (ret) @@ -347,6 +357,7 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name, char *realname = NULL, *filename = NULL, *dir_name = NULL, *linkname = zalloc(size), *targetname, *tmp; int err = -1; + int lockfd; if (!is_kallsyms) { realname = realpath(name, NULL); @@ -358,30 +369,34 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name, if (!dir_name) goto out_free; - if (mkdir_p(dir_name, 0755)) + buildid_dir_write_lock(&lockfd); + if (lockfd == -1) goto out_free; + if (mkdir_p(dir_name, 0755)) + goto out_unlock; + if (asprintf(&filename, "%s/%s", dir_name, sbuild_id) < 0) { filename = NULL; - goto out_free; + goto out_unlock; } if (access(filename, F_OK)) { if (is_kallsyms) { if (copyfile("/proc/kallsyms", filename)) - goto out_free; + goto out_unlock; } else if (link(realname, filename) && errno != EEXIST && copyfile(name, filename)) - goto out_free; + goto out_unlock; } if (!build_id__filename(sbuild_id, linkname, size)) - goto out_free; + goto out_unlock; tmp = strrchr(linkname, '/'); *tmp = '\0'; if (access(linkname, X_OK) && mkdir_p(linkname, 0755)) - goto out_free; + goto out_unlock; *tmp = '/'; targetname = filename + strlen(buildid_dir) - 5; @@ -389,6 +404,8 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name, if (symlink(targetname, linkname) == 0) err = 0; +out_unlock: + buildid_dir_write_unlock(lockfd); out_free: if (!is_kallsyms) free(realname); @@ -427,6 +444,7 @@ int build_id_cache__remove_s(const char *sbuild_id) char *filename = zalloc(size), *linkname = zalloc(size), *tmp; int err = -1; + int lockfd = -1; if (filename == NULL || linkname == NULL) goto out_free; @@ -449,10 +467,17 @@ int build_id_cache__remove_s(const char *sbuild_id) tmp = strrchr(linkname, '/') + 1; snprintf(tmp, size - (tmp - linkname), "%s", filename); - if (unlink(linkname)) + buildid_dir_write_lock(&lockfd); + if (lockfd == -1) goto out_free; + if (unlink(linkname)) + goto out_unlock; + + err = 0; +out_unlock: + buildid_dir_write_unlock(lockfd); out_free: free(filename); free(linkname); -- 2.4.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
