Commit 5202efe5 authored by Nicolas Iooss's avatar Nicolas Iooss Committed by Linus Torvalds
Browse files

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

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: default avatarNicolas Iooss <>
Acked-by: default avatar"Eric W. Biederman" <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 89bfae43
......@@ -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
%s signal number
......@@ -209,11 +209,15 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm)
/* uid */
case 'u':
err = cn_printf(cn, "%d", cred->uid);
err = cn_printf(cn, "%u",
/* gid */
case 'g':
err = cn_printf(cn, "%d", cred->gid);
err = cn_printf(cn, "%u",
case 'd':
err = cn_printf(cn, "%d",
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment