From 4f48da008d1fb3ccab2ad76523c104aa3fa8d8b6 Mon Sep 17 00:00:00 2001 From: Szabolcs Nagy Date: Sat, 16 Jul 2022 15:55:51 +0200 Subject: aarch64: add vfork The generic vfork implementation uses clone(SIGCHLD) which has fork semantics. Implement vfork as clone(SIGCHLD|CLONE_VM|CLONE_VFORK, 0) instead which has vfork semantics. (stack == 0 means sp is unchanged in the child.) Some users rely on vfork semantics when memory overcommit is disabled or when the vfork child runs code that synchronizes with the parent process (non-conforming). --- src/process/aarch64/vfork.s | 9 +++++++++ 1 file changed, 9 insertions(+) create mode 100644 src/process/aarch64/vfork.s diff --git a/src/process/aarch64/vfork.s b/src/process/aarch64/vfork.s new file mode 100644 index 00000000..429bec8c --- /dev/null +++ b/src/process/aarch64/vfork.s @@ -0,0 +1,9 @@ +.global vfork +.type vfork,%function +vfork: + mov x8, 220 // SYS_clone + mov x0, 0x4111 // SIGCHLD | CLONE_VM | CLONE_VFORK + mov x1, 0 + svc 0 + .hidden __syscall_ret + b __syscall_ret -- cgit v1.2.1