From ce96593c882b393461084048533120e9c1e9d328 Mon Sep 17 00:00:00 2001 From: Sergey Bugaev Date: Mon, 15 May 2023 11:33:21 +0300 Subject: [PATCH] hurd: Align signal stack pointer after allocating stackframe sizeof (*stackframe) appears to be divisible by 16, but we should not rely on that. So make sure to leave enough space for the stackframe first, and then align the final pointer at 16 bytes. Checked on x86_64-gnu. Signed-off-by: Sergey Bugaev Message-Id: <20230515083323.1358039-3-bugaevc@gmail.com> --- sysdeps/mach/hurd/x86/trampoline.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/sysdeps/mach/hurd/x86/trampoline.c b/sysdeps/mach/hurd/x86/trampoline.c index 19bddad..1f92064 100644 --- a/sysdeps/mach/hurd/x86/trampoline.c +++ b/sysdeps/mach/hurd/x86/trampoline.c @@ -196,15 +196,14 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action #endif } + /* Push the arguments to call `trampoline' on the stack. */ + sigsp -= sizeof (*stackframe); #ifdef __x86_64__ /* Align SP at 16 bytes. Coupled with the fact that sigreturn_addr is 16-byte aligned within the stackframe struct, this ensures that it ends up on a 16-byte aligned address, as required by the ABI. */ sigsp = (void *) ((uintptr_t) sigsp & ~15UL); #endif - - /* Push the arguments to call `trampoline' on the stack. */ - sigsp -= sizeof (*stackframe); stackframe = sigsp; if (_hurdsig_catch_memory_fault (stackframe)) -- 2.7.4