diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-01-19 09:33:40 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-01-19 09:33:40 -0800 |
| commit | 9528d418de4d83c7ada69314ddd8d4427b1f703a (patch) | |
| tree | 5f11d953115f6c454a45d75e471a9e2e472b9839 | |
| parent | 25144ea31b90af6fa860e1ce3ab735d8bb8deb83 (diff) | |
| parent | ae02ae16b76160f0aeeae2c5fb9b15226d00a4ef (diff) | |
Merge tag 'x86_urgent_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Mark serialize() noinstr so that it can be used from instrumentation-
free code
- Make sure FRED's RSP0 MSR is synchronized with its corresponding
per-CPU value in order to avoid double faults in hotplug scenarios
- Disable EXECMEM_ROX on x86 for now because it didn't receive proper
x86 maintainers review, went in and broke a bunch of things
* tag 'x86_urgent_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm: Make serialize() always_inline
x86/fred: Fix the FRED RSP0 MSR out of sync with its per-CPU cache
x86: Disable EXECMEM_ROX support
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/special_insns.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/fred.c | 8 |
3 files changed, 8 insertions, 3 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 9d7bd0ae48c4..ef6cfea9df73 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -83,7 +83,6 @@ config X86 select ARCH_HAS_DMA_OPS if GART_IOMMU || XEN select ARCH_HAS_EARLY_DEBUG if KGDB select ARCH_HAS_ELF_RANDOMIZE - select ARCH_HAS_EXECMEM_ROX if X86_64 select ARCH_HAS_FAST_MULTIPLIER select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_GCOV_PROFILE_ALL diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h index aec6e2d3aa1d..98bfc097389c 100644 --- a/arch/x86/include/asm/special_insns.h +++ b/arch/x86/include/asm/special_insns.h @@ -217,7 +217,7 @@ fail: #define nop() asm volatile ("nop") -static inline void serialize(void) +static __always_inline void serialize(void) { /* Instruction opcode for SERIALIZE; supported in binutils >= 2.35. */ asm volatile(".byte 0xf, 0x1, 0xe8" ::: "memory"); diff --git a/arch/x86/kernel/fred.c b/arch/x86/kernel/fred.c index 8d32c3f48abc..5e2cd1004980 100644 --- a/arch/x86/kernel/fred.c +++ b/arch/x86/kernel/fred.c @@ -50,7 +50,13 @@ void cpu_init_fred_exceptions(void) FRED_CONFIG_ENTRYPOINT(asm_fred_entrypoint_user)); wrmsrl(MSR_IA32_FRED_STKLVLS, 0); - wrmsrl(MSR_IA32_FRED_RSP0, 0); + + /* + * Ater a CPU offline/online cycle, the FRED RSP0 MSR should be + * resynchronized with its per-CPU cache. + */ + wrmsrl(MSR_IA32_FRED_RSP0, __this_cpu_read(fred_rsp0)); + wrmsrl(MSR_IA32_FRED_RSP1, 0); wrmsrl(MSR_IA32_FRED_RSP2, 0); wrmsrl(MSR_IA32_FRED_RSP3, 0); |