diff options
| author | Theo de Raadt <deraadt@cvs.openbsd.org> | 2020-03-13 09:31:27 +0000 |
|---|---|---|
| committer | Theo de Raadt <deraadt@cvs.openbsd.org> | 2020-03-13 09:31:27 +0000 |
| commit | 3dd873d5712775c0f8f07378b93f5270bf0f4ef6 (patch) | |
| tree | edf42e35ea95c1842f599ffebbfefc2096aa2d82 /libexec | |
| parent | 87f4e84920fae5bab9dcc347f162a069b18ace3b (diff) | |
Anthony Steinhauser reports that 32-bit arm cpus have the same speculation
problems as 64-bit models. To resolve the syscall speculation, as a first
step "nop; nop" was added after all occurances of the syscall ("swi 0")
instruction. Then the kernel was changed to jump over the 2 extra instructions.
In this final step, those pair of nops are converted into the speculation-blocking
sequence ("dsb nsh; isb").
Don't try to build through these multiple steps, use a snapshot instead.
Packages matching the new ABI will be out in a while...
ok kettenis
Diffstat (limited to 'libexec')
| -rw-r--r-- | libexec/ld.so/arm/SYS.h | 6 | ||||
| -rw-r--r-- | libexec/ld.so/arm/rtld_machine.c | 4 |
2 files changed, 5 insertions, 5 deletions
diff --git a/libexec/ld.so/arm/SYS.h b/libexec/ld.so/arm/SYS.h index 2147c2a81c5..1e86515631a 100644 --- a/libexec/ld.so/arm/SYS.h +++ b/libexec/ld.so/arm/SYS.h @@ -1,4 +1,4 @@ -/* $OpenBSD: SYS.h,v 1.2 2020/03/11 12:53:21 deraadt Exp $ */ +/* $OpenBSD: SYS.h,v 1.3 2020/03/13 09:31:26 deraadt Exp $ */ /* * Copyright (c) 2004 Dale Rahn @@ -32,8 +32,8 @@ #define SYSTRAP(x) \ ldr r12, =SYS_ ## x; \ swi 0; \ - nop; \ - nop + dsb nsh; \ + isb #define DL_SYSCALL(n) \ .global __CONCAT(_dl_,n) ;\ diff --git a/libexec/ld.so/arm/rtld_machine.c b/libexec/ld.so/arm/rtld_machine.c index db20e9507ae..6df418b20ea 100644 --- a/libexec/ld.so/arm/rtld_machine.c +++ b/libexec/ld.so/arm/rtld_machine.c @@ -1,4 +1,4 @@ -/* $OpenBSD: rtld_machine.c,v 1.40 2020/03/13 06:38:55 deraadt Exp $ */ +/* $OpenBSD: rtld_machine.c,v 1.41 2020/03/13 09:31:26 deraadt Exp $ */ /* * Copyright (c) 2004 Dale Rahn @@ -364,7 +364,7 @@ _dl_bind(elf_object_t *object, int relidx) register long arg3 __asm("r2") = 0xffffffff & cookie; register long arg4 __asm("r3") = 0xffffffff & (cookie >> 32); - __asm volatile("swi 0; nop; nop" : "+r" (arg1), "+r" (arg2) + __asm volatile("swi 0; dsb nsh; isb" : "+r" (arg1), "+r" (arg2) : "r" (syscall_num), "r" (arg3), "r" (arg4) : "cc", "memory"); } |