lkl: fix 32-bit timespec casts

On 32-bit architectures, struct lkl_timespec is 2*sizeof(long) while __lkl__kernel_timespec is 2*sizeof(long long); casting these pointer types is unsafe. Fixes: 3d4047a ("lkl: follow up fixes after v5.1 merge (y2038)") Signed-off-by: David Disseldorp <[email protected]>
lkl · Feb 5, 2025 · 0692c1e · 0692c1e
1 parent ab1c2d0
commit 0692c1e
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Showing 3 changed files with 35 additions and 34 deletions.
diff --git a/tools/lkl/cptofs.c b/tools/lkl/cptofs.c
@@ -463,22 +463,24 @@ static int do_entry(const char *_src, const char *_dst, const char *name, uid_t
 		printf("skipping %s: unsupported entry type %d\n", src, type);
 	}
 
-	if (!ret) {
-		if (cptofs) {
-			struct lkl_timespec lkl_ts[] = { atime, mtime };
+	if (ret)
+		goto err_out;
 
-			ret = lkl_sys_utimensat(LKL_AT_FDCWD, dst,
-						(struct __lkl__kernel_timespec
-						 *)lkl_ts,
-						LKL_AT_SYMLINK_NOFOLLOW);
-		} else {
-			struct timespec ts[] = {
-				{ .tv_sec = atime.tv_sec, .tv_nsec = atime.tv_nsec, },
-				{ .tv_sec = mtime.tv_sec, .tv_nsec = mtime.tv_nsec, },
-			};
+	if (cptofs) {
+		struct __lkl__kernel_timespec lkl_ts[] = {
+			{ .tv_sec = atime.tv_sec, .tv_nsec = atime.tv_nsec, },
+			{ .tv_sec = mtime.tv_sec, .tv_nsec = mtime.tv_nsec, },
+		};
 
-			ret = utimensat(AT_FDCWD, dst, ts, AT_SYMLINK_NOFOLLOW);
-		}
+		ret = lkl_sys_utimensat(LKL_AT_FDCWD, dst, lkl_ts,
+					LKL_AT_SYMLINK_NOFOLLOW);
+	} else {
+		struct timespec ts[] = {
+			{ .tv_sec = atime.tv_sec, .tv_nsec = atime.tv_nsec, },
+			{ .tv_sec = mtime.tv_sec, .tv_nsec = mtime.tv_nsec, },
+		};
+
+		ret = utimensat(AT_FDCWD, dst, ts, AT_SYMLINK_NOFOLLOW);
 	}
 
 err_out:

diff --git a/tools/lkl/include/lkl.h b/tools/lkl/include/lkl.h
@@ -276,7 +276,7 @@ static inline long lkl_sys_select(int n, lkl_fd_set *rfds, lkl_fd_set *wfds,
 				  lkl_fd_set *efds, struct lkl_timeval *tv)
 {
 	long data[2] = { 0, _LKL_NSIG/8 };
-	struct lkl_timespec ts;
+	struct __lkl__kernel_timespec ts;
 
 	if (tv) {
 		if (tv->tv_sec < 0 || tv->tv_usec < 0)
@@ -285,8 +285,7 @@ static inline long lkl_sys_select(int n, lkl_fd_set *rfds, lkl_fd_set *wfds,
 		ts.tv_sec = tv->tv_sec;
 		ts.tv_nsec = tv->tv_usec * 1000;
 	}
-	return lkl_sys_pselect6(n, rfds, wfds, efds, tv ?
-				(struct __lkl__kernel_timespec *)&ts : 0, data);
+	return lkl_sys_pselect6(n, rfds, wfds, efds, tv ?  &ts : 0, data);
 }
 #endif
 
@@ -296,11 +295,15 @@ static inline long lkl_sys_select(int n, lkl_fd_set *rfds, lkl_fd_set *wfds,
  */
 static inline long lkl_sys_poll(struct lkl_pollfd *fds, int n, int timeout)
 {
-	return lkl_sys_ppoll(fds, n, timeout >= 0 ?
-			     (struct __lkl__kernel_timespec *)
-			     &((struct lkl_timespec){ .tv_sec = timeout/1000,
-				   .tv_nsec = timeout%1000*1000000 }) : 0,
-			     0, _LKL_NSIG/8);
+	struct __lkl__kernel_timespec ts;
+
+	if (timeout >= 0)
+		ts = (struct __lkl__kernel_timespec){
+			.tv_sec = timeout / 1000,
+			.tv_nsec = timeout % 1000 * 1000000,
+		};
+
+	return lkl_sys_ppoll(fds, n, timeout >= 0 ? &ts : 0, 0, _LKL_NSIG/8);
 }
 #endif
 

diff --git a/tools/lkl/lklfuse.c b/tools/lkl/lklfuse.c
@@ -503,19 +503,16 @@ static int lklfuse_utimens(const char *path, const struct timespec tv[2],
 			   struct fuse_file_info *fi)
 {
 	int ret;
-	struct lkl_timespec ts[2] = {
+	struct __lkl__kernel_timespec ts[2] = {
 		{ .tv_sec = tv[0].tv_sec, .tv_nsec = tv[0].tv_nsec },
 		{ .tv_sec = tv[1].tv_sec, .tv_nsec = tv[1].tv_nsec },
 	};
 
 	if (fi)
-		ret = lkl_sys_utimensat(fi->fh, NULL,
-					(struct __lkl__kernel_timespec *)ts,
-					0);
+		ret = lkl_sys_utimensat(fi->fh, NULL, ts, 0);
 	else
-		ret = lkl_sys_utimensat(-1, path,
-					(struct __lkl__kernel_timespec *)ts,
-					LKL_AT_SYMLINK_NOFOLLOW);
+		ret = lkl_sys_utimensat(-1, path, ts, LKL_AT_SYMLINK_NOFOLLOW);
+
 	return ret;
 }
 
@@ -686,7 +683,7 @@ static int start_lkl(void)
 	long ret;
 	char mpoint[32];
 	struct timespec walltime;
-	struct lkl_timespec ts;
+	struct __lkl__kernel_timespec ts;
 	int mount_flags = 0;
 	char remaining_mopts[4096] = { 0 };
 
@@ -709,10 +706,9 @@ static int start_lkl(void)
 	if (ret < 0)
 		goto out_halt;
 
-	ts = (struct lkl_timespec){ .tv_sec = walltime.tv_sec,
-				    .tv_nsec = walltime.tv_nsec };
-	ret = lkl_sys_clock_settime(LKL_CLOCK_REALTIME,
-				    (struct __lkl__kernel_timespec *)&ts);
+	ts = (struct __lkl__kernel_timespec){ .tv_sec = walltime.tv_sec,
+					      .tv_nsec = walltime.tv_nsec };
+	ret = lkl_sys_clock_settime(LKL_CLOCK_REALTIME, &ts);
 	if (ret < 0) {
 		fprintf(stderr, "lkl_sys_clock_settime() failed: %s\n",
 			lkl_strerror(ret));