Eric Lee / linux-smarc-t335x-v3.2

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Commit eb84a20e9e6b98dcb33023ad22241d79107a08a7

Authored by Alan Cox
Committed by Linus Torvalds
1 parent 5f412b2424

[PATCH] audit/accounting: tty locking 

Add tty locking around the audit and accounting code.

The whole current->signal-> locking is all deeply strange but it's for
someone else to sort out.  Add rather than replace the lock for acct.c

Signed-off-by: Alan Cox <alan@redhat.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Showing 2 changed files with 10 additions and 1 deletions Side-by-side Diff

... ... @@ -483,10 +483,14 @@
483 483 ac.ac_ppid = current->parent->tgid;
484 484 #endif
485 485  
486   - read_lock(&tasklist_lock); /* pin current->signal */
  486 + mutex_lock(&tty_mutex);
  487 + /* FIXME: Whoever is responsible for current->signal locking needs
  488 + to use the same locking all over the kernel and document it */
  489 + read_lock(&tasklist_lock);
487 490 ac.ac_tty = current->signal->tty ?
488 491 old_encode_dev(tty_devnum(current->signal->tty)) : 0;
489 492 read_unlock(&tasklist_lock);
  493 + mutex_unlock(&tty_mutex);
490 494  
491 495 spin_lock_irq(&current->sighand->siglock);
492 496 ac.ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime)));
... ... @@ -817,6 +817,8 @@
817 817 audit_log_format(ab, " success=%s exit=%ld",
818 818 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
819 819 context->return_code);
  820 +
  821 + mutex_lock(&tty_mutex);
820 822 if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
821 823 tty = tsk->signal->tty->name;
822 824 else
... ... @@ -838,6 +840,9 @@
838 840 context->gid,
839 841 context->euid, context->suid, context->fsuid,
840 842 context->egid, context->sgid, context->fsgid, tty);
  843 +
  844 + mutex_unlock(&tty_mutex);
  845 +
841 846 audit_log_task_info(ab, tsk);
842 847 if (context->filterkey) {
843 848 audit_log_format(ab, " key=");