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 /lib/libc | |
| 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 'lib/libc')
| -rw-r--r-- | lib/libc/arch/arm/SYS.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/lib/libc/arch/arm/SYS.h b/lib/libc/arch/arm/SYS.h index f1a6eadf797..5d12784c3ec 100644 --- a/lib/libc/arch/arm/SYS.h +++ b/lib/libc/arch/arm/SYS.h @@ -1,4 +1,4 @@ -/* $OpenBSD: SYS.h,v 1.17 2020/03/11 12:53:19 deraadt Exp $ */ +/* $OpenBSD: SYS.h,v 1.18 2020/03/13 09:31:24 deraadt Exp $ */ /* $NetBSD: SYS.h,v 1.8 2003/08/07 16:42:02 agc Exp $ */ /*- @@ -55,8 +55,8 @@ #define SYSTRAP(x) \ ldr r12, =SYS_ ## x; \ swi 0; \ - nop; \ - nop + dsb nsh; \ + isb #define CERROR _C_LABEL(__cerror) |