From 5202efe544c279be152f44f2821010ff7b2d7e5b Mon Sep 17 00:00:00 2001 From: Nicolas Iooss Date: Thu, 25 Jun 2015 15:03:51 -0700 Subject: coredump: use from_kuid/kgid when formatting corename When adding __printf attribute to cn_printf, gcc reports some issues: fs/coredump.c:213:5: warning: format '%d' expects argument of type 'int', but argument 3 has type 'kuid_t' [-Wformat=] err = cn_printf(cn, "%d", cred->uid); ^ fs/coredump.c:217:5: warning: format '%d' expects argument of type 'int', but argument 3 has type 'kgid_t' [-Wformat=] err = cn_printf(cn, "%d", cred->gid); ^ These warnings come from the fact that the value of uid/gid needs to be extracted from the kuid_t/kgid_t structure before being used as an integer. More precisely, cred->uid and cred->gid need to be converted to either user-namespace uid/gid or to init_user_ns uid/gid. Use init_user_ns in order not to break existing ABI, and document this in Documentation/sysctl/kernel.txt. While at it, format uid and gid values with %u instead of %d because uid_t/__kernel_uid32_t and gid_t/__kernel_gid32_t are unsigned int. Signed-off-by: Nicolas Iooss Acked-by: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/coredump.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'fs/coredump.c') diff --git a/fs/coredump.c b/fs/coredump.c index bbbe139ab280..833a57bc856c 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -209,11 +209,15 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm) break; /* uid */ case 'u': - err = cn_printf(cn, "%d", cred->uid); + err = cn_printf(cn, "%u", + from_kuid(&init_user_ns, + cred->uid)); break; /* gid */ case 'g': - err = cn_printf(cn, "%d", cred->gid); + err = cn_printf(cn, "%u", + from_kgid(&init_user_ns, + cred->gid)); break; case 'd': err = cn_printf(cn, "%d", -- cgit