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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-11-17 09:35:51 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-11-17 09:35:51 -0800 |
| commit | f66d6acccbc08b4146f4c2cf9445241f70f5517d (patch) | |
| tree | 39000388d92a0428a5953f0af1b8fd0f0ef6c355 /arch/x86/kernel | |
| parent | 4a5df37964673effcd9f84041f7423206a5ae5f2 (diff) | |
| parent | 8d9ffb2fe65a6c4ef114e8d4f947958a12751bbe (diff) | |
| download | lwn-f66d6acccbc08b4146f4c2cf9445241f70f5517d.tar.gz lwn-f66d6acccbc08b4146f4c2cf9445241f70f5517d.zip | |
Merge tag 'x86_urgent_for_v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Make sure a kdump kernel with CONFIG_IMA_KEXEC enabled and booted on
an AMD SME enabled hardware properly decrypts the ima_kexec buffer
information passed to it from the previous kernel
- Fix building the kernel with Clang where a non-TLS definition of the
stack protector guard cookie leads to bogus code generation
- Clear a wrongly advertised virtualized VMLOAD/VMSAVE feature flag on
some Zen4 client systems as those insns are not supported on client
* tag 'x86_urgent_for_v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Fix a kdump kernel failure on SME system when CONFIG_IMA_KEXEC=y
x86/stackprotector: Work around strict Clang TLS symbol requirements
x86/CPU/AMD: Clear virtualized VMLOAD/VMSAVE on Zen4 client
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/amd.c | 11 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 3 |
3 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index fab5caec0b72..823f44f7bc94 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -924,6 +924,17 @@ static void init_amd_zen4(struct cpuinfo_x86 *c) { if (!cpu_has(c, X86_FEATURE_HYPERVISOR)) msr_set_bit(MSR_ZEN4_BP_CFG, MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT); + + /* + * These Zen4 SoCs advertise support for virtualized VMLOAD/VMSAVE + * in some BIOS versions but they can lead to random host reboots. + */ + switch (c->x86_model) { + case 0x18 ... 0x1f: + case 0x60 ... 0x7f: + clear_cpu_cap(c, X86_FEATURE_V_VMSAVE_VMLOAD); + break; + } } static void init_amd_zen5(struct cpuinfo_x86 *c) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index a5f221ea5688..f43bb974fc66 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2089,8 +2089,10 @@ void syscall_init(void) #ifdef CONFIG_STACKPROTECTOR DEFINE_PER_CPU(unsigned long, __stack_chk_guard); +#ifndef CONFIG_SMP EXPORT_PER_CPU_SYMBOL(__stack_chk_guard); #endif +#endif #endif /* CONFIG_X86_64 */ diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index b8c5741d2fb4..feb8102a9ca7 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -491,6 +491,9 @@ SECTIONS . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE), "kernel image bigger than KERNEL_IMAGE_SIZE"); +/* needed for Clang - see arch/x86/entry/entry.S */ +PROVIDE(__ref_stack_chk_guard = __stack_chk_guard); + #ifdef CONFIG_X86_64 /* * Per-cpu symbols which need to be offset from __per_cpu_load |