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| author | Nicolas Iooss <nicolas.iooss_linux@m4x.org> | 2015-06-26 01:03:51 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-26 03:00:43 +0300 |
| commit | 5202efe544c279be152f44f2821010ff7b2d7e5b (patch) | |
| tree | 35d7726c6314074c18963cd08d7351ea50f1f0db | |
| parent | 89bfae43c8999344c3025802a3652ac42f55278e (diff) | |
| download | linux-5202efe544c279be152f44f2821010ff7b2d7e5b.tar.xz | |
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 <nicolas.iooss_linux@m4x.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | Documentation/sysctl/kernel.txt | 4 | ||||
| -rw-r--r-- | fs/coredump.c | 8 |
2 files changed, 8 insertions, 4 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index e5d528e0c46e..6fccb69c03e7 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -197,8 +197,8 @@ core_pattern is used to specify a core dumpfile pattern name. %P global pid (init PID namespace) %i tid %I global tid (init PID namespace) - %u uid - %g gid + %u uid (in initial user namespace) + %g gid (in initial user namespace) %d dump mode, matches PR_SET_DUMPABLE and /proc/sys/fs/suid_dumpable %s signal number 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", |