[PATCH 2/2] um: Handle SIGCHLD in seccomp mode like other IRQ signals

[Tiwei Bie]

In seccomp mode, SIGCHLD serves as the child reaper IRQ. So, let's
handle it in the same way as other IRQ signals, including preventing
them from nesting with each other and allowing interrupted syscalls
to be automatically restarted.

Signed-off-by: Tiwei Bie <tiwei.btw at antgroup.com>
---
 arch/um/os-Linux/signal.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c
index de372b936a80..6c993bc8c78e 100644
--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -16,6 +16,7 @@
 #include <as-layout.h>
 #include <kern_util.h>
 #include <os.h>
+#include <skas.h>
 #include <sysdep/mcontext.h>
 #include <um_malloc.h>
 #include <sys/ucontext.h>
@@ -224,6 +225,8 @@ void set_handler(int sig)
 	sigaddset(&action.sa_mask, SIGIO);
 	sigaddset(&action.sa_mask, SIGWINCH);
 	sigaddset(&action.sa_mask, SIGALRM);
+	if (using_seccomp)
+		sigaddset(&action.sa_mask, SIGCHLD);
 
 	if (sig == SIGSEGV)
 		flags |= SA_NODEFER;
-- 
2.34.1