[PATCH v8 06/14] task_isolation: provide strict mode configurable signal
From: Chris Metcalf <hidden>
Date: 2015-10-20 20:37:02
Also in:
lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
Allow userspace to override the default SIGKILL delivered when a task_isolation process in STRICT mode does a syscall or otherwise synchronously enters the kernel. Signed-off-by: Chris Metcalf <redacted> --- include/uapi/linux/prctl.h | 2 ++ kernel/isolation.c | 9 ++++++++- 2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h
index 2b8038b0d1e1..a5582ace987f 100644
--- a/include/uapi/linux/prctl.h
+++ b/include/uapi/linux/prctl.h@@ -202,5 +202,7 @@ struct prctl_mm_map { #define PR_GET_TASK_ISOLATION 49 # define PR_TASK_ISOLATION_ENABLE (1 << 0) # define PR_TASK_ISOLATION_STRICT (1 << 1) +# define PR_TASK_ISOLATION_SET_SIG(sig) (((sig) & 0x7f) << 8) +# define PR_TASK_ISOLATION_GET_SIG(bits) (((bits) >> 8) & 0x7f) #endif /* _LINUX_PRCTL_H */
diff --git a/kernel/isolation.c b/kernel/isolation.c
index 30db40098a35..0fa13b081bb4 100644
--- a/kernel/isolation.c
+++ b/kernel/isolation.c@@ -84,8 +84,10 @@ void _task_isolation_enter(void) */ bool task_isolation_exception(const char *fmt, ...) { + siginfo_t info = {}; va_list args; char buf[100]; + int sig; /* RCU should have been enabled prior to this point. */ RCU_LOCKDEP_WARN(!rcu_is_watching(), "kernel entry without RCU");
@@ -97,7 +99,12 @@ bool task_isolation_exception(const char *fmt, ...) pr_warn("%s/%d: task_isolation strict mode violated by %s\n", current->comm, current->pid, buf); current->task_isolation_flags &= ~PR_TASK_ISOLATION_ENABLE; - send_sig(SIGKILL, current, 1); + + sig = PR_TASK_ISOLATION_GET_SIG(current->task_isolation_flags); + if (sig == 0) + sig = SIGKILL; + info.si_signo = sig; + send_sig_info(sig, &info, current); return true; }
--
2.1.2