[PATCH 2/2] cleanup the usage of SEND_SIG_xxx constants

From: Oleg Nesterov
Date: Sun Sep 18 2005 - 08:39:56 EST


This patch simplifies some checks for magic siginfo values.
It should not change the behaviour in any way.

Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>

--- 2.6.14-rc1/include/linux/sched.h~2_CLEAN 2005-09-17 18:57:30.000000000 +0400
+++ 2.6.14-rc1/include/linux/sched.h 2005-09-18 19:14:09.000000000 +0400
@@ -1015,6 +1015,11 @@ extern int do_sigaltstack(const stack_t
#define SEND_SIG_PRIV ((struct siginfo *) 1)
#define SEND_SIG_FORCED ((struct siginfo *) 2)

+static inline int is_si_special(const struct siginfo *info)
+{
+ return info <= SEND_SIG_FORCED;
+}
+
/* True if we are on the alternate signal stack. */

static inline int on_sig_stack(unsigned long sp)
--- 2.6.14-rc1/kernel/signal.c~2_CLEAN 2005-09-18 18:36:23.000000000 +0400
+++ 2.6.14-rc1/kernel/signal.c 2005-09-18 19:12:35.000000000 +0400
@@ -661,9 +661,7 @@ static int check_kill_permission(int sig
if (!valid_signal(sig))
return error;
error = -EPERM;
- if ((info == SEND_SIG_NOINFO ||
- (info != SEND_SIG_PRIV && info != SEND_SIG_FORCED
- && SI_FROMUSER(info)))
+ if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info)))
&& ((sig != SIGCONT) ||
(current->signal->session != t->signal->session))
&& (current->euid ^ t->suid) && (current->euid ^ t->uid)
@@ -812,7 +810,7 @@ static int send_signal(int sig, struct s
pass on the info struct. */

q = __sigqueue_alloc(t, GFP_ATOMIC, (sig < SIGRTMIN &&
- (info < SEND_SIG_FORCED ||
+ (is_si_special(info) ||
info->si_code >= 0)));
if (q) {
list_add_tail(&q->list, &signals->list);
@@ -835,16 +833,14 @@ static int send_signal(int sig, struct s
copy_siginfo(&q->info, info);
break;
}
- } else {
- if (sig >= SIGRTMIN
- && info != SEND_SIG_NOINFO && info != SEND_SIG_PRIV
- && info->si_code != SI_USER)
+ } else if (!is_si_special(info)) {
+ if (sig >= SIGRTMIN && info->si_code != SI_USER)
/*
* Queue overflow, abort. We may abort if the signal was rt
* and sent by user using something other than kill().
*/
return -EAGAIN;
- if ((info > SEND_SIG_PRIV) && (info->si_code == SI_TIMER))
+ if (info->si_code == SI_TIMER)
/*
* Set up a return to indicate that we dropped
* the signal.
@@ -870,7 +866,7 @@ specific_send_sig_info(int sig, struct s
BUG();
assert_spin_locked(&t->sighand->siglock);

- if ((info > SEND_SIG_FORCED) && (info->si_code == SI_TIMER))
+ if (!is_si_special(info) && (info->si_code == SI_TIMER))
/*
* Set up a return to indicate that we dropped the signal.
*/
@@ -1065,7 +1061,7 @@ __group_send_sig_info(int sig, struct si
assert_spin_locked(&p->sighand->siglock);
handle_stop_signal(sig, p);

- if ((info > SEND_SIG_FORCED) && (info->si_code == SI_TIMER))
+ if (!is_si_special(info) && (info->si_code == SI_TIMER))
/*
* Set up a return to indicate that we dropped the signal.
*/
--- 2.6.14-rc1/security/selinux/hooks.c~2_CLEAN 2005-09-18 17:55:07.000000000 +0400
+++ 2.6.14-rc1/security/selinux/hooks.c 2005-09-18 19:24:47.000000000 +0400
@@ -2688,8 +2688,7 @@ static int selinux_task_kill(struct task
if (rc)
return rc;

- if (info != SEND_SIG_NOINFO && (info == SEND_SIG_PRIV ||
- info == SEND_SIG_FORCED || SI_FROMKERNEL(info)))
+ if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info)))
return 0;

if (!sig)
-
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