From eb84a20e9e6b98dcb33023ad22241d79107a08a7 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Fri, 29 Sep 2006 02:01:41 -0700 Subject: [PATCH] [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 Acked-by: Arjan van de Ven Cc: Al Viro Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/acct.c | 6 +++++- kernel/auditsc.c | 5 +++++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/kernel/acct.c b/kernel/acct.c index 2a7c933..f4330ac 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -483,10 +483,14 @@ static void do_acct_process(struct file *file) ac.ac_ppid = current->parent->tgid; #endif - read_lock(&tasklist_lock); /* pin current->signal */ + mutex_lock(&tty_mutex); + /* FIXME: Whoever is responsible for current->signal locking needs + to use the same locking all over the kernel and document it */ + read_lock(&tasklist_lock); ac.ac_tty = current->signal->tty ? old_encode_dev(tty_devnum(current->signal->tty)) : 0; read_unlock(&tasklist_lock); + mutex_unlock(&tty_mutex); spin_lock_irq(¤t->sighand->siglock); ac.ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime))); diff --git a/kernel/auditsc.c b/kernel/auditsc.c index fb83c5c..1051476 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -817,6 +817,8 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts audit_log_format(ab, " success=%s exit=%ld", (context->return_valid==AUDITSC_SUCCESS)?"yes":"no", context->return_code); + + mutex_lock(&tty_mutex); if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) tty = tsk->signal->tty->name; else @@ -838,6 +840,9 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts context->gid, context->euid, context->suid, context->fsuid, context->egid, context->sgid, context->fsgid, tty); + + mutex_unlock(&tty_mutex); + audit_log_task_info(ab, tsk); if (context->filterkey) { audit_log_format(ab, " key="); -- 1.8.2.3