summaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
Diffstat (limited to 'kernel')
-rw-r--r--kernel/entry/syscall_user_dispatch.c12
-rw-r--r--kernel/kthread.c2
-rw-r--r--kernel/reboot.c1
-rw-r--r--kernel/signal.c34
4 files changed, 33 insertions, 16 deletions
diff --git a/kernel/entry/syscall_user_dispatch.c b/kernel/entry/syscall_user_dispatch.c
index c240302f56e2..4508201847d2 100644
--- a/kernel/entry/syscall_user_dispatch.c
+++ b/kernel/entry/syscall_user_dispatch.c
@@ -47,14 +47,18 @@ bool syscall_user_dispatch(struct pt_regs *regs)
* access_ok() is performed once, at prctl time, when
* the selector is loaded by userspace.
*/
- if (unlikely(__get_user(state, sd->selector)))
- do_exit(SIGSEGV);
+ if (unlikely(__get_user(state, sd->selector))) {
+ force_fatal_sig(SIGSEGV);
+ return true;
+ }
if (likely(state == SYSCALL_DISPATCH_FILTER_ALLOW))
return false;
- if (state != SYSCALL_DISPATCH_FILTER_BLOCK)
- do_exit(SIGSYS);
+ if (state != SYSCALL_DISPATCH_FILTER_BLOCK) {
+ force_fatal_sig(SIGSYS);
+ return true;
+ }
}
sd->on_dispatch = true;
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 4a4d7092a2d8..7113003fab63 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -433,7 +433,7 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
* If thread is going to be bound on a particular cpu, give its node
* in @node, to get NUMA affinity for kthread stack, or else give NUMA_NO_NODE.
* When woken, the thread will run @threadfn() with @data as its
- * argument. @threadfn() can either call do_exit() directly if it is a
+ * argument. @threadfn() can either return directly if it is a
* standalone thread for which no one will call kthread_stop(), or
* return when 'kthread_should_stop()' is true (which means
* kthread_stop() has been called). The return value should be zero
diff --git a/kernel/reboot.c b/kernel/reboot.c
index f7440c0c7e43..d6e0f9fb7f04 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -359,7 +359,6 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
case LINUX_REBOOT_CMD_HALT:
kernel_halt();
do_exit(0);
- panic("cannot halt");
case LINUX_REBOOT_CMD_POWER_OFF:
kernel_power_off();
diff --git a/kernel/signal.c b/kernel/signal.c
index 6f3476dc7873..7c4b7ae714d4 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1323,6 +1323,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool
blocked = sigismember(&t->blocked, sig);
if (blocked || ignored || sigdfl) {
action->sa.sa_handler = SIG_DFL;
+ action->sa.sa_flags |= SA_IMMUTABLE;
if (blocked) {
sigdelset(&t->blocked, sig);
recalc_sigpending_and_wake(t);
@@ -1649,6 +1650,19 @@ void force_sig(int sig)
}
EXPORT_SYMBOL(force_sig);
+void force_fatal_sig(int sig)
+{
+ struct kernel_siginfo info;
+
+ clear_siginfo(&info);
+ info.si_signo = sig;
+ info.si_errno = 0;
+ info.si_code = SI_KERNEL;
+ info.si_pid = 0;
+ info.si_uid = 0;
+ force_sig_info_to_task(&info, current, true);
+}
+
/*
* When things go south during signal handling, we
* will force a SIGSEGV. And if the signal that caused
@@ -1657,15 +1671,10 @@ EXPORT_SYMBOL(force_sig);
*/
void force_sigsegv(int sig)
{
- struct task_struct *p = current;
-
- if (sig == SIGSEGV) {
- unsigned long flags;
- spin_lock_irqsave(&p->sighand->siglock, flags);
- p->sighand->action[sig - 1].sa.sa_handler = SIG_DFL;
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
- }
- force_sig(SIGSEGV);
+ if (sig == SIGSEGV)
+ force_fatal_sig(SIGSEGV);
+ else
+ force_sig(SIGSEGV);
}
int force_sig_fault_to_task(int sig, int code, void __user *addr
@@ -2704,7 +2713,8 @@ relock:
if (!signr)
break; /* will return 0 */
- if (unlikely(current->ptrace) && signr != SIGKILL) {
+ if (unlikely(current->ptrace) && (signr != SIGKILL) &&
+ !(sighand->action[signr -1].sa.sa_flags & SA_IMMUTABLE)) {
signr = ptrace_signal(signr, &ksig->info);
if (!signr)
continue;
@@ -4054,6 +4064,10 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
k = &p->sighand->action[sig-1];
spin_lock_irq(&p->sighand->siglock);
+ if (k->sa.sa_flags & SA_IMMUTABLE) {
+ spin_unlock_irq(&p->sighand->siglock);
+ return -EINVAL;
+ }
if (oact)
*oact = *k;