diff options
| -rw-r--r-- | include/linux/signal_types.h | 3 | ||||
| -rw-r--r-- | include/uapi/asm-generic/signal-defs.h | 1 | ||||
| -rw-r--r-- | kernel/signal.c | 8 |
3 files changed, 11 insertions, 1 deletions
diff --git a/include/linux/signal_types.h b/include/linux/signal_types.h index 34cb28b8f16c..a70b2bdbf4d9 100644 --- a/include/linux/signal_types.h +++ b/include/linux/signal_types.h @@ -70,6 +70,9 @@ struct ksignal { int sig; }; +/* Used to kill the race between sigaction and forced signals */ +#define SA_IMMUTABLE 0x00800000 + #ifndef __ARCH_UAPI_SA_FLAGS #ifdef SA_RESTORER #define __ARCH_UAPI_SA_FLAGS SA_RESTORER diff --git a/include/uapi/asm-generic/signal-defs.h b/include/uapi/asm-generic/signal-defs.h index fe929e7b77ca..7572f2f46ee8 100644 --- a/include/uapi/asm-generic/signal-defs.h +++ b/include/uapi/asm-generic/signal-defs.h @@ -45,6 +45,7 @@ #define SA_UNSUPPORTED 0x00000400 #define SA_EXPOSE_TAGBITS 0x00000800 /* 0x00010000 used on mips */ +/* 0x00800000 used for internal SA_IMMUTABLE */ /* 0x01000000 used on x86 */ /* 0x02000000 used on x86 */ /* diff --git a/kernel/signal.c b/kernel/signal.c index 6a5e1802b9a2..056a107e3cbc 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1336,6 +1336,7 @@ 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); @@ -2760,7 +2761,8 @@ 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; @@ -4110,6 +4112,10 @@ 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; |