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authorAlan Cox <alan@redhat.com>2008-10-13 11:40:53 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-13 18:51:42 +0200
commitdbda4c0b97b18fd59b3964548361b4f92357f730 (patch)
treeca7e2827541aec01762f2a9c0e3155aaf49bf0ca
parenttty: Redo current tty locking (diff)
downloadlinux-dbda4c0b97b18fd59b3964548361b4f92357f730.tar.xz
linux-dbda4c0b97b18fd59b3964548361b4f92357f730.zip
tty: Fix abusers of current->sighand->tty
Various people outside the tty layer still stick their noses in behind the scenes. We need to make sure they also obey the locking and referencing rules. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/acct.c2
-rw-r--r--kernel/auditsc.c9
2 files changed, 5 insertions, 6 deletions
diff --git a/kernel/acct.c b/kernel/acct.c
index dd68b9059418..f6006a60df5d 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -548,7 +548,7 @@ static void do_acct_process(struct bsd_acct_struct *acct,
#endif
spin_lock_irq(&current->sighand->siglock);
- tty = current->signal->tty;
+ tty = current->signal->tty; /* Safe as we hold the siglock */
ac.ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0;
ac.ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime)));
ac.ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime)));
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 59cedfb040e7..cf5bc2f5f9c3 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -246,8 +246,8 @@ static int audit_match_perm(struct audit_context *ctx, int mask)
unsigned n;
if (unlikely(!ctx))
return 0;
-
n = ctx->major;
+
switch (audit_classify_syscall(ctx->arch, n)) {
case 0: /* native */
if ((mask & AUDIT_PERM_WRITE) &&
@@ -1204,13 +1204,13 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
(context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
context->return_code);
- mutex_lock(&tty_mutex);
- read_lock(&tasklist_lock);
+ spin_lock_irq(&tsk->sighand->siglock);
if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
tty = tsk->signal->tty->name;
else
tty = "(none)";
- read_unlock(&tasklist_lock);
+ spin_unlock_irq(&tsk->sighand->siglock);
+
audit_log_format(ab,
" a0=%lx a1=%lx a2=%lx a3=%lx items=%d"
" ppid=%d pid=%d auid=%u uid=%u gid=%u"
@@ -1230,7 +1230,6 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
context->egid, context->sgid, context->fsgid, tty,
tsk->sessionid);
- mutex_unlock(&tty_mutex);
audit_log_task_info(ab, tsk);
if (context->filterkey) {