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| author | Oleg Nesterov <oleg@redhat.com> | 2009-12-15 16:47:22 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-16 07:20:08 -0800 |
| commit | 614c517d7c00af1b26ded20646b329397d6f51a1 (patch) | |
| tree | ddd7a82b3479c9fabe141b4c82a1794650a82b4f /kernel/signal.c | |
| parent | d51965037325e51f6cd68583413243c3573e47b0 (diff) | |
| download | lwn-614c517d7c00af1b26ded20646b329397d6f51a1.tar.gz lwn-614c517d7c00af1b26ded20646b329397d6f51a1.zip | |
signals: SEND_SIG_NOINFO should be considered as SI_FROMUSER()
No changes in compiled code. The patch adds the new helper, si_fromuser()
and changes check_kill_permission() to use this helper.
The real effect of this patch is that from now we "officially" consider
SEND_SIG_NOINFO signal as "from user-space" signals. This is already true
if we look at the code which uses SEND_SIG_NOINFO, except __send_signal()
has another opinion - see the next patch.
The naming of these special SEND_SIG_XXX siginfo's is really bad
imho. From __send_signal()'s pov they mean
SEND_SIG_NOINFO from user
SEND_SIG_PRIV from kernel
SEND_SIG_FORCED no info
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Reviewed-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 6b982f2cf524..a0ba428954b6 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -607,6 +607,17 @@ static int rm_from_queue(unsigned long mask, struct sigpending *s) return 1; } +static inline int is_si_special(const struct siginfo *info) +{ + return info <= SEND_SIG_FORCED; +} + +static inline bool si_fromuser(const struct siginfo *info) +{ + return info == SEND_SIG_NOINFO || + (!is_si_special(info) && SI_FROMUSER(info)); +} + /* * Bad permissions for sending the signal * - the caller must hold at least the RCU read lock @@ -621,7 +632,7 @@ static int check_kill_permission(int sig, struct siginfo *info, if (!valid_signal(sig)) return -EINVAL; - if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info))) + if (!si_fromuser(info)) return 0; error = audit_signal_info(sig, t); /* Let audit system see the signal */ @@ -1186,8 +1197,7 @@ int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, goto out_unlock; } pcred = __task_cred(p); - if ((info == SEND_SIG_NOINFO || - (!is_si_special(info) && SI_FROMUSER(info))) && + if (si_fromuser(info) && euid != pcred->suid && euid != pcred->uid && uid != pcred->suid && uid != pcred->uid) { ret = -EPERM; |