diff options
| author | Mark Kettenis <kettenis@cvs.openbsd.org> | 2020-01-26 02:19:45 +0000 |
|---|---|---|
| committer | Mark Kettenis <kettenis@cvs.openbsd.org> | 2020-01-26 02:19:45 +0000 |
| commit | 0ec8c6b435bb55fc0772bb3076380d3ce30b2c72 (patch) | |
| tree | 1d775542b140394e8c53b525297c68d12d3e6a0f /libexec/ld.so | |
| parent | 675d8462e190fecce5396b0b9c999a26ab2246b1 (diff) | |
Insert two nop instructions after each svc #0 instruction in userland.
The will be replaced by a speculation barrier as soon as we teach the
kernel to skip over these two instructions when returning from a
system call.
ok patrick@, deraadt@
Diffstat (limited to 'libexec/ld.so')
| -rw-r--r-- | libexec/ld.so/aarch64/SYS.h | 10 | ||||
| -rw-r--r-- | libexec/ld.so/aarch64/rtld_machine.c | 4 |
2 files changed, 8 insertions, 6 deletions
diff --git a/libexec/ld.so/aarch64/SYS.h b/libexec/ld.so/aarch64/SYS.h index 8131bd9b9fb..46ed6aca5c0 100644 --- a/libexec/ld.so/aarch64/SYS.h +++ b/libexec/ld.so/aarch64/SYS.h @@ -1,4 +1,4 @@ -/* $OpenBSD: SYS.h,v 1.3 2018/10/01 22:53:48 mortimer Exp $ */ +/* $OpenBSD: SYS.h,v 1.4 2020/01/26 02:19:44 kettenis Exp $ */ /* * Copyright (c) 2016 Dale Rahn @@ -29,9 +29,11 @@ #include <machine/asm.h> #include <sys/syscall.h> -#define SYSTRAP(x) \ - ldr x8, =SYS_ ## x; \ - svc 0 +#define SYSTRAP(x) \ + ldr x8, =SYS_ ## x ;\ + svc 0 ;\ + nop ;\ + nop #define DL_SYSCALL(n) \ .global __CONCAT(_dl_,n) ;\ diff --git a/libexec/ld.so/aarch64/rtld_machine.c b/libexec/ld.so/aarch64/rtld_machine.c index 5ac50d715cf..d466b5a1776 100644 --- a/libexec/ld.so/aarch64/rtld_machine.c +++ b/libexec/ld.so/aarch64/rtld_machine.c @@ -1,4 +1,4 @@ -/* $OpenBSD: rtld_machine.c,v 1.18 2019/12/07 22:57:47 guenther Exp $ */ +/* $OpenBSD: rtld_machine.c,v 1.19 2020/01/26 02:19:44 kettenis Exp $ */ /* * Copyright (c) 2004 Dale Rahn @@ -300,7 +300,7 @@ _dl_bind(elf_object_t *object, int relidx) register long arg2 __asm("x1") = sizeof(buf); register long arg3 __asm("x2") = cookie; - __asm volatile("svc 0" : "+r" (arg1), "+r" (arg2) + __asm volatile("svc 0; nop; nop" : "+r" (arg1), "+r" (arg2) : "r" (syscall_num), "r" (arg3) : "cc", "memory"); } |