diff options
| author | Philip Guenthe <guenther@cvs.openbsd.org> | 2012-04-17 16:02:34 +0000 |
|---|---|---|
| committer | Philip Guenthe <guenther@cvs.openbsd.org> | 2012-04-17 16:02:34 +0000 |
| commit | 916f161cd9b4c3fb17be9c3d32e0618df7e72911 (patch) | |
| tree | 47c92610a5a1b18537f8eb1278d6805f235c3220 | |
| parent | 55b040815206d7dce82f59a01096792b5b766e98 (diff) | |
Don't try to cache the CPU's FS.base, as userland can make it a lie by
setting %fs, resulting in it not getting restored properly later
ok mikeb@ deraadt@
| -rw-r--r-- | sys/arch/amd64/amd64/cpu.c | 3 | ||||
| -rw-r--r-- | sys/arch/amd64/amd64/genassym.cf | 3 | ||||
| -rw-r--r-- | sys/arch/amd64/include/cpu.h | 3 | ||||
| -rw-r--r-- | sys/arch/amd64/include/frameasm.h | 14 |
4 files changed, 6 insertions, 17 deletions
diff --git a/sys/arch/amd64/amd64/cpu.c b/sys/arch/amd64/amd64/cpu.c index 1221401cf42..f5444285b3d 100644 --- a/sys/arch/amd64/amd64/cpu.c +++ b/sys/arch/amd64/amd64/cpu.c @@ -1,4 +1,4 @@ -/* $OpenBSD: cpu.c,v 1.47 2012/04/04 18:44:22 mikeb Exp $ */ +/* $OpenBSD: cpu.c,v 1.48 2012/04/17 16:02:33 guenther Exp $ */ /* $NetBSD: cpu.c,v 1.1 2003/04/26 18:39:26 fvdl Exp $ */ /*- @@ -681,7 +681,6 @@ cpu_init_msrs(struct cpu_info *ci) wrmsr(MSR_CSTAR, (uint64_t)Xsyscall32); wrmsr(MSR_SFMASK, PSL_NT|PSL_T|PSL_I|PSL_C); - ci->ci_cur_fsbase = 0; wrmsr(MSR_FSBASE, 0); wrmsr(MSR_GSBASE, (u_int64_t)ci); wrmsr(MSR_KERNELGSBASE, 0); diff --git a/sys/arch/amd64/amd64/genassym.cf b/sys/arch/amd64/amd64/genassym.cf index db292d709a4..5ae35085109 100644 --- a/sys/arch/amd64/amd64/genassym.cf +++ b/sys/arch/amd64/amd64/genassym.cf @@ -1,4 +1,4 @@ -# $OpenBSD: genassym.cf,v 1.28 2011/04/13 02:49:12 guenther Exp $ +# $OpenBSD: genassym.cf,v 1.29 2012/04/17 16:02:33 guenther Exp $ # Written by Artur Grabowski art@openbsd.org, Public Domain include <sys/param.h> @@ -99,7 +99,6 @@ member tss_rsp0 struct cpu_info member CPU_INFO_SCRATCH ci_scratch -member CPU_INFO_CUR_FSBASE ci_cur_fsbase member CPU_INFO_SELF ci_self member CPU_INFO_CPUID ci_cpuid member CPU_INFO_APICID ci_apicid diff --git a/sys/arch/amd64/include/cpu.h b/sys/arch/amd64/include/cpu.h index 8b4e3dcb6e8..e06bea011f5 100644 --- a/sys/arch/amd64/include/cpu.h +++ b/sys/arch/amd64/include/cpu.h @@ -1,4 +1,4 @@ -/* $OpenBSD: cpu.h,v 1.72 2012/04/04 18:44:22 mikeb Exp $ */ +/* $OpenBSD: cpu.h,v 1.73 2012/04/17 16:02:33 guenther Exp $ */ /* $NetBSD: cpu.h,v 1.1 2003/04/26 18:39:39 fvdl Exp $ */ /*- @@ -72,7 +72,6 @@ struct cpu_info { u_int32_t ci_randseed; u_int64_t ci_scratch; - u_int64_t ci_cur_fsbase; struct proc *ci_fpcurproc; struct proc *ci_fpsaveproc; diff --git a/sys/arch/amd64/include/frameasm.h b/sys/arch/amd64/include/frameasm.h index 83388ab874d..95a1e0faa25 100644 --- a/sys/arch/amd64/include/frameasm.h +++ b/sys/arch/amd64/include/frameasm.h @@ -1,4 +1,4 @@ -/* $OpenBSD: frameasm.h,v 1.6 2011/07/04 15:54:24 guenther Exp $ */ +/* $OpenBSD: frameasm.h,v 1.7 2012/04/17 16:02:33 guenther Exp $ */ /* $NetBSD: frameasm.h,v 1.1 2003/04/26 18:39:40 fvdl Exp $ */ #ifndef _AMD64_MACHINE_FRAMEASM_H @@ -65,22 +65,14 @@ movw $(GSEL(GUDATA_SEL, SEL_UPL)),%ax ; \ movw %ax,%ds ; \ /* Make sure both %fs and FS.base are the desired values */ \ + movw TF_FS(%rsp),%fs ; \ movq PCB_FSBASE(%rdx),%rax ; \ cmpq $0,%rax ; \ - jne 96f ; \ - movw TF_FS(%rsp),%fs /* zero FS.base by setting %fs */ ; \ - jmp 98f ; \ -96: cmpq CPUVAR(CUR_FSBASE),%rax ; \ - jne 97f ; \ - movw %fs,%cx /* FS.base same, how about %fs? */ ; \ - cmpw TF_FS(%rsp),%cx ; \ - je 99f ; \ -97: movw TF_FS(%rsp),%fs /* set them both */ ; \ + je 99f /* setting %fs has zeroed FS.base */ ; \ movq %rax,%rdx ; \ shrq $32,%rdx ; \ movl $MSR_FSBASE,%ecx ; \ wrmsr ; \ -98: movq %rax,CPUVAR(CUR_FSBASE) ; \ 99: cli /* %fs done, so swapgs and do %gs */ ; \ swapgs ; \ movw TF_GS(%rsp),%gs |