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| author | Borislav Petkov (AMD) <bp@alien8.de> | 2023-05-15 16:07:26 +0200 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-05-17 12:14:21 +0200 |
| commit | f220125b999b2c9694149c6bda2798d8096f47ed (patch) | |
| tree | 7cee09cfdcadf0a27866192d98be136f3a388130 /arch/x86/lib | |
| parent | x86/cpu: Remove X86_FEATURE_NAMES (diff) | |
| download | linux-f220125b999b2c9694149c6bda2798d8096f47ed.tar.xz linux-f220125b999b2c9694149c6bda2798d8096f47ed.zip | |
x86/retbleed: Add __x86_return_thunk alignment checks
Add a linker assertion and compute the 0xcc padding dynamically so that
__x86_return_thunk is always cacheline-aligned. Leave the SYM_START()
macro in as the untraining doesn't need ENDBR annotations anyway.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Link: https://lore.kernel.org/r/20230515140726.28689-1-bp@alien8.de
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/retpoline.S | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S index b3b1e376dce8..3fd066d42ec0 100644 --- a/arch/x86/lib/retpoline.S +++ b/arch/x86/lib/retpoline.S @@ -143,7 +143,7 @@ SYM_CODE_END(__x86_indirect_jump_thunk_array) * from re-poisioning the BTB prediction. */ .align 64 - .skip 63, 0xcc + .skip 64 - (__x86_return_thunk - zen_untrain_ret), 0xcc SYM_START(zen_untrain_ret, SYM_L_GLOBAL, SYM_A_NONE) ANNOTATE_NOENDBR /* |