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| author | Peter Zijlstra <peterz@infradead.org> | 2022-06-27 22:21:17 +0000 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2022-06-29 17:43:41 +0200 |
| commit | f43b9876e857c739d407bc56df288b0ebe1a9164 (patch) | |
| tree | 22fcf2716b615556869c460a71ed3fd9b1393bd6 /arch/x86/entry | |
| parent | 26aae8ccbc1972233afd08fb3f368947c0314265 (diff) | |
| download | linux-f43b9876e857c739d407bc56df288b0ebe1a9164.tar.gz | |
x86/retbleed: Add fine grained Kconfig knobs
Do fine-grained Kconfig for all the various retbleed parts. NOTE: if your compiler doesn't support return thunks this will silently 'upgrade' your mitigation to IBPB, you might not like this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/calling.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index 074d04e434de..f6907627172b 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -297,6 +297,7 @@ For 32-bit we have the following conventions - kernel is built with * Assumes x86_spec_ctrl_{base,current} to have SPEC_CTRL_IBRS set. */ .macro IBRS_ENTER save_reg +#ifdef CONFIG_CPU_IBRS_ENTRY ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_KERNEL_IBRS movl $MSR_IA32_SPEC_CTRL, %ecx @@ -317,6 +318,7 @@ For 32-bit we have the following conventions - kernel is built with shr $32, %rdx wrmsr .Lend_\@: +#endif .endm /* @@ -324,6 +326,7 @@ For 32-bit we have the following conventions - kernel is built with * regs. Must be called after the last RET. */ .macro IBRS_EXIT save_reg +#ifdef CONFIG_CPU_IBRS_ENTRY ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_KERNEL_IBRS movl $MSR_IA32_SPEC_CTRL, %ecx @@ -338,6 +341,7 @@ For 32-bit we have the following conventions - kernel is built with shr $32, %rdx wrmsr .Lend_\@: +#endif .endm /* |