[PATCH] samples/vfs: fix printf format string for size_t

[PATCH] samples/vfs: fix printf format string for size_t

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

size_t needs a %z format string modifier instead of %l

samples/vfs/test-list-all-mounts.c:152:39: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
  152 |                                         printf("mnt_uidmap[%lu]:\t%s\n", idx, idmap);
      |                                                            ~~~           ^~~
      |                                                            %zu
samples/vfs/test-list-all-mounts.c:161:39: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
  161 |                                         printf("mnt_gidmap[%lu]:\t%s\n", idx, idmap);
      |                                                            ~~~           ^~~
      |                                                            %zu

Fixes: fa204a65f1b6 ("samples/vfs: add STATMOUNT_MNT_{G,U}IDMAP")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 samples/vfs/test-list-all-mounts.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/samples/vfs/test-list-all-mounts.c b/samples/vfs/test-list-all-mounts.c
index bb3b83d8f1d7..713c174626aa 100644
--- a/samples/vfs/test-list-all-mounts.c
+++ b/samples/vfs/test-list-all-mounts.c
@@ -149,7 +149,7 @@ int main(int argc, char *argv[])
 				const char *idmap = stmnt->str + stmnt->mnt_uidmap;
 
 				for (size_t idx = 0; idx < stmnt->mnt_uidmap_num; idx++) {
-					printf("mnt_uidmap[%lu]:\t%s\n", idx, idmap);
+					printf("mnt_uidmap[%zu]:\t%s\n", idx, idmap);
 					idmap += strlen(idmap) + 1;
 				}
 			}
@@ -158,7 +158,7 @@ int main(int argc, char *argv[])
 				const char *idmap = stmnt->str + stmnt->mnt_gidmap;
 
 				for (size_t idx = 0; idx < stmnt->mnt_gidmap_num; idx++) {
-					printf("mnt_gidmap[%lu]:\t%s\n", idx, idmap);
+					printf("mnt_gidmap[%zu]:\t%s\n", idx, idmap);
 					idmap += strlen(idmap) + 1;
 				}
 			}
-- 
2.39.5

Re: [PATCH] samples/vfs: fix printf format string for size_t

[Christian Brauner]

On Mon, 24 Feb 2025 15:14:00 +0100, Arnd Bergmann wrote:
> size_t needs a %z format string modifier instead of %l
> 
> samples/vfs/test-list-all-mounts.c:152:39: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
>   152 |                                         printf("mnt_uidmap[%lu]:\t%s\n", idx, idmap);
>       |                                                            ~~~           ^~~
>       |                                                            %zu
> samples/vfs/test-list-all-mounts.c:161:39: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
>   161 |                                         printf("mnt_gidmap[%lu]:\t%s\n", idx, idmap);
>       |                                                            ~~~           ^~~
>       |                                                            %zu
> 
> [...]

Applied to the vfs-6.15.mount branch of the vfs/vfs.git tree.
Patches in the vfs-6.15.mount branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-6.15.mount

[1/1] samples/vfs: fix printf format string for size_t
      https://git.kernel.org/vfs/vfs/c/33cec19dc022