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[1/4] um: Add os_set_pdeathsig helper function

Message ID 20241024142828.2612828-2-tiwei.btw@antgroup.com
State Accepted
Headers show
Series um: Set parent-death signal for sub-processes | expand

Commit Message

Tiwei Bie Oct. 24, 2024, 2:28 p.m. UTC 
This helper can be used to set the parent-death signal of the calling
process to SIGKILL to ensure that the process will be killed if the
UML kernel dies unexpectedly without proper cleanup. This helper will
be used in the follow-up patches.

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
---
 arch/um/include/shared/os.h | 2 ++
 arch/um/os-Linux/process.c  | 6 ++++++
 2 files changed, 8 insertions(+)
diff mbox series

Patch

diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h
index 09f8201de5db..d709a24dc6fc 100644
--- a/arch/um/include/shared/os.h
+++ b/arch/um/include/shared/os.h
@@ -216,6 +216,8 @@  extern int os_drop_memory(void *addr, int length);
 extern int can_drop_memory(void);
 extern int os_mincore(void *addr, unsigned long len);
 
+void os_set_pdeathsig(void);
+
 /* execvp.c */
 extern int execvp_noalloc(char *buf, const char *file, char *const argv[]);
 /* helper.c */
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index f20602e793d9..9f086f939420 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -12,6 +12,7 @@ 
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <sys/ptrace.h>
+#include <sys/prctl.h>
 #include <sys/wait.h>
 #include <asm/unistd.h>
 #include <init.h>
@@ -203,3 +204,8 @@  void init_new_thread_signals(void)
 	set_handler(SIGIO);
 	signal(SIGWINCH, SIG_IGN);
 }
+
+void os_set_pdeathsig(void)
+{
+	prctl(PR_SET_PDEATHSIG, SIGKILL);
+}