From: Borislav Petkov <bp@suse.de>
Date: Mon, 15 Jun 2020 08:51:25 +0200
Subject: x86/speculation: Merge one test in
spectre_v2_user_select_mitigation()
Git-commit: a5ce9f2bb665d1d2b31f139a02dbaa2dfbb62fa6
Patch-mainline: v5.9-rc1
References: bsc#1191580 CVE-2022-0001 CVE-2022-0002
Merge the test whether the CPU supports STIBP into the test which
determines whether STIBP is required. Thus try to simplify what is
already an insane logic.
Remove a superfluous newline in a comment, while at it.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Anthony Steinhauser <asteinhauser@google.com>
Link: https://lkml.kernel.org/r/20200615065806.GB14668@zn.tnic
---
arch/x86/kernel/cpu/bugs.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -785,19 +785,14 @@ spectre_v2_user_select_mitigation(enum s
}
/*
- * If enhanced IBRS is enabled or SMT impossible, STIBP is not
+ * If no STIBP, enhanced IBRS is enabled or SMT impossible, STIBP is not
* required.
*/
- if (!smt_possible || spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
+ if (!boot_cpu_has(X86_FEATURE_STIBP) ||
+ !smt_possible ||
+ spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
return;
- /*
- * If SMT is not possible or STIBP is not available clear the STIPB
- * mode.
- */
- if (!boot_cpu_has(X86_FEATURE_STIBP))
- mode = SPECTRE_V2_USER_NONE;
-
spectre_v2_user_stibp = mode;
set_mode: