From: Emil Velikov <emil.l.velikov@gmail.com>
Date: Sat, 24 May 2025 15:10:11 +0000 (+0100)
Subject: tools/depmod: use nsec granularity when checking timestamps
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=249795046644e1be82d36e3e7f46497949b3d650;p=thirdparty%2Fkmod.git

tools/depmod: use nsec granularity when checking timestamps

Current code uses the POSIX.1-2001 stat::st_mtime which has one second
granularity. Considering the depmod execution time may be smaller, we
should be using the POSIX.1-2008 stat::st_mtim which has nano-second
granularity instead.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/359
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
---

diff --git a/shared/util.c b/shared/util.c
index 571f4afa..b09f7662 100644
--- a/shared/util.c
+++ b/shared/util.c
@@ -497,7 +497,7 @@ int fd_lookup_path(int fd, char *path, size_t pathlen)
 	return len;
 }
 
-static unsigned long long ts_usec(const struct timespec *ts)
+unsigned long long ts_usec(const struct timespec *ts)
 {
 	return (unsigned long long)ts->tv_sec * USEC_PER_SEC +
 	       (unsigned long long)ts->tv_nsec / NSEC_PER_USEC;
diff --git a/shared/util.h b/shared/util.h
index 1f59ec44..fd03736a 100644
--- a/shared/util.h
+++ b/shared/util.h
@@ -63,6 +63,7 @@ _nonnull_all_ int fd_lookup_path(int fd, char *path, size_t pathlen);
 #define MSEC_PER_SEC 1000ULL
 #define NSEC_PER_MSEC 1000000ULL
 
+unsigned long long ts_usec(const struct timespec *ts);
 unsigned long long now_usec(void);
 unsigned long long now_msec(void);
 int sleep_until_msec(unsigned long long msec);
diff --git a/tools/depmod.c b/tools/depmod.c
index 3390222a..3f8c9381 100644
--- a/tools/depmod.c
+++ b/tools/depmod.c
@@ -2768,7 +2768,8 @@ invalid_syntax:
 	return 0;
 }
 
-static int depfile_up_to_date_dir(DIR *d, time_t mtime, size_t baselen, char *path)
+static int depfile_up_to_date_dir(DIR *d, const struct timespec *ts, size_t baselen,
+				  char *path)
 {
 	struct dirent *de;
 	int err = 1, dfd = dirfd(d);
@@ -2816,7 +2817,7 @@ static int depfile_up_to_date_dir(DIR *d, time_t mtime, size_t baselen, char *pa
 			}
 			path[baselen + namelen] = '/';
 			path[baselen + namelen + 1] = '\0';
-			err = depfile_up_to_date_dir(subdir, mtime, baselen + namelen + 1,
+			err = depfile_up_to_date_dir(subdir, ts, baselen + namelen + 1,
 						     path);
 			closedir(subdir);
 		} else if (S_ISREG(st.st_mode)) {
@@ -2824,10 +2825,11 @@ static int depfile_up_to_date_dir(DIR *d, time_t mtime, size_t baselen, char *pa
 				continue;
 
 			memcpy(path + baselen, name, namelen + 1);
-			err = st.st_mtime <= mtime;
+			err = ts_usec(&st.st_mtim) <= ts_usec(ts);
 			if (err == 0) {
 				DBG("%s %" PRIu64 " is newer than %" PRIu64 "\n", path,
-				    (uint64_t)st.st_mtime, (uint64_t)mtime);
+				    (uint64_t)ts_usec(&st.st_mtim),
+				    (uint64_t)ts_usec(ts));
 			}
 		} else {
 			ERR("unsupported file type %s: %o\n", path, st.st_mode & S_IFMT);
@@ -2873,7 +2875,7 @@ static int depfile_up_to_date(const char *dirname)
 	baselen++;
 	path[baselen] = '\0';
 
-	err = depfile_up_to_date_dir(d, st.st_mtime, baselen, path);
+	err = depfile_up_to_date_dir(d, &st.st_mtim, baselen, path);
 	closedir(d);
 	return err;
 }