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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-11 10:14:02 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-11 10:14:02 -0700 |
| commit | 4c605260bc60347d3d5601900704cb22b0b2efec (patch) | |
| tree | 8b08d1c10e246fede635770b6059de01da77f31a | |
| parent | 65d7ca5987f29f4c3d5c0889d2f046bb246d18d4 (diff) | |
| parent | a37f2699c36a7f6606ba3300f243227856c5ad6b (diff) | |
Merge tag 'x86_urgent_for_v6.4_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fix from Borislav Petkov:
- Set up the kernel CS earlier in the boot process in case EFI boots
the kernel after bypassing the decompressor and the CS descriptor
used ends up being the EFI one which is not mapped in the identity
page table, leading to early SEV/SNP guest communication exceptions
resulting in the guest crashing
* tag 'x86_urgent_for_v6.4_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/head/64: Switch to KERNEL_CS as soon as new GDT is installed
| -rw-r--r-- | arch/x86/kernel/head_64.S | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index a5df3e994f04..113c13376e51 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -77,6 +77,15 @@ SYM_CODE_START_NOALIGN(startup_64) call startup_64_setup_env popq %rsi + /* Now switch to __KERNEL_CS so IRET works reliably */ + pushq $__KERNEL_CS + leaq .Lon_kernel_cs(%rip), %rax + pushq %rax + lretq + +.Lon_kernel_cs: + UNWIND_HINT_END_OF_STACK + #ifdef CONFIG_AMD_MEM_ENCRYPT /* * Activate SEV/SME memory encryption if supported/enabled. This needs to @@ -90,15 +99,6 @@ SYM_CODE_START_NOALIGN(startup_64) popq %rsi #endif - /* Now switch to __KERNEL_CS so IRET works reliably */ - pushq $__KERNEL_CS - leaq .Lon_kernel_cs(%rip), %rax - pushq %rax - lretq - -.Lon_kernel_cs: - UNWIND_HINT_END_OF_STACK - /* Sanitize CPU configuration */ call verify_cpu |