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| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-12 10:44:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-12 10:44:24 -0700 |
| commit | 87194efe7ecdf8d145c7cef130fda9652bf77fd7 (patch) | |
| tree | 3df8089c58a7c967ab793ac63b337b9e75a3b8e7 /arch/x86/entry/entry_64.S | |
| parent | Merge tag 'x86_misc_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (diff) | |
| parent | selftests/x86/fsgsbase: Test PTRACE_PEEKUSER for GSBASE with invalid LDT GS (diff) | |
| download | wireguard-linux-87194efe7ecdf8d145c7cef130fda9652bf77fd7.tar.xz wireguard-linux-87194efe7ecdf8d145c7cef130fda9652bf77fd7.zip | |
Merge tag 'x86_fsgsbase_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fsgsbase updates from Borislav Petkov:
"Misc minor cleanups and corrections to the fsgsbase code and
respective selftests"
* tag 'x86_fsgsbase_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
selftests/x86/fsgsbase: Test PTRACE_PEEKUSER for GSBASE with invalid LDT GS
selftests/x86/fsgsbase: Reap a forgotten child
x86/fsgsbase: Replace static_cpu_has() with boot_cpu_has()
x86/entry/64: Correct the comment over SAVE_AND_SET_GSBASE
Diffstat (limited to 'arch/x86/entry/entry_64.S')
| -rw-r--r-- | arch/x86/entry/entry_64.S | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index d977079a7d02..748c2db3c54e 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -842,8 +842,9 @@ SYM_CODE_START_LOCAL(paranoid_entry) * retrieve and set the current CPUs kernel GSBASE. The stored value * has to be restored in paranoid_exit unconditionally. * - * The MSR write ensures that no subsequent load is based on a - * mispredicted GSBASE. No extra FENCE required. + * The unconditional write to GS base below ensures that no subsequent + * loads based on a mispredicted GS base can happen, therefore no LFENCE + * is needed here. */ SAVE_AND_SET_GSBASE scratch_reg=%rax save_reg=%rbx ret |