diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-08-12 08:34:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-08-12 08:34:20 -0700 |
| commit | 272b86ba9d97518b3c14b97514b6544eef87e7a5 (patch) | |
| tree | 038a5b84e3e61ff0470d53ef1f7be2447ab52f58 /arch | |
| parent | f8de32cc060ba3f63171aaa0e8764d22d8c37978 (diff) | |
| parent | 3477144c878a52fc3938a529186e81ea030e7779 (diff) | |
Merge tag 'x86_bugs_for_v6.5_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mitigation fixes from Borislav Petkov:
"The first set of fallout fixes after the embargo madness. There will
be another set next week too.
- A first series of cleanups/unifications and documentation
improvements to the SRSO and GDS mitigations code which got
postponed to after the embargo date
- Fix the SRSO aliasing addresses assertion so that the LLVM linker
can parse it too"
* tag 'x86_bugs_for_v6.5_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
driver core: cpu: Fix the fallback cpu_show_gds() name
x86: Move gds_ucode_mitigated() declaration to header
x86/speculation: Add cpu_show_gds() prototype
driver core: cpu: Make cpu_show_not_affected() static
x86/srso: Fix build breakage with the LLVM linker
Documentation/srso: Document IBPB aspect and fix formatting
driver core: cpu: Unify redundant silly stubs
Documentation/hw-vuln: Unify filename specification in index
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/processor.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 12 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 2 |
3 files changed, 11 insertions, 5 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 973db0406528..4ae2773b873d 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -731,4 +731,6 @@ bool arch_is_platform_page(u64 paddr); #define arch_is_platform_page arch_is_platform_page #endif +extern bool gds_ucode_mitigated(void); + #endif /* _ASM_X86_PROCESSOR_H */ diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index e76813230192..ef06211bae4c 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -529,11 +529,17 @@ INIT_PER_CPU(irq_stack_backing_store); #ifdef CONFIG_CPU_SRSO /* - * GNU ld cannot do XOR so do: (A | B) - (A & B) in order to compute the XOR + * GNU ld cannot do XOR until 2.41. + * https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=f6f78318fca803c4907fb8d7f6ded8295f1947b1 + * + * LLVM lld cannot do XOR until lld-17. + * https://github.com/llvm/llvm-project/commit/fae96104d4378166cbe5c875ef8ed808a356f3fb + * + * Instead do: (A | B) - (A & B) in order to compute the XOR * of the two function addresses: */ -. = ASSERT(((srso_untrain_ret_alias | srso_safe_ret_alias) - - (srso_untrain_ret_alias & srso_safe_ret_alias)) == ((1 << 2) | (1 << 8) | (1 << 14) | (1 << 20)), +. = ASSERT(((ABSOLUTE(srso_untrain_ret_alias) | srso_safe_ret_alias) - + (ABSOLUTE(srso_untrain_ret_alias) & srso_safe_ret_alias)) == ((1 << 2) | (1 << 8) | (1 << 14) | (1 << 20)), "SRSO function pair won't alias"); #endif diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 19d9ff92d699..c381770bcbf1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -314,8 +314,6 @@ u64 __read_mostly host_xcr0; static struct kmem_cache *x86_emulator_cache; -extern bool gds_ucode_mitigated(void); - /* * When called, it means the previous get/set msr reached an invalid msr. * Return true if we want to ignore/silent this failed msr access. |