From: "Borislav Petkov (AMD)" bp@alien8.de
stable inclusion from stable-v5.10.192 commit 0e8139f92304cef82ac769cfb51dda341a17fb1c category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I7RQ67
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 6405b72e8d17bd1875a56ae52d23ec3cd51b9d66 upstream.
Specify how is SRSO mitigated when SMT is disabled. Also, correct the SMT check for that.
Fixes: e9fbc47b818b ("x86/srso: Disable the mitigation on unaffected configurations") Suggested-by: Josh Poimboeuf jpoimboe@kernel.org Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Acked-by: Josh Poimboeuf jpoimboe@kernel.org Link: https://lore.kernel.org/r/20230814200813.p5czl47zssuej7nv@treble Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Jialin Zhang zhangjialin11@huawei.com (cherry picked from commit d3b2e775575120d687f87b93d2afc9c8b764cbee) Signed-off-by: Jialin Zhang zhangjialin11@huawei.com --- arch/x86/kernel/cpu/bugs.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index f3620e725004..8bbc88149f0c 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -2362,8 +2362,7 @@ static void __init srso_select_mitigation(void) * Zen1/2 with SMT off aren't vulnerable after the right * IBPB microcode has been applied. */ - if ((boot_cpu_data.x86 < 0x19) && - (!cpu_smt_possible() || (cpu_smt_control == CPU_SMT_DISABLED))) { + if (boot_cpu_data.x86 < 0x19 && !cpu_smt_possible()) { setup_force_cpu_cap(X86_FEATURE_SRSO_NO); return; } @@ -2653,7 +2652,7 @@ static ssize_t gds_show_state(char *buf) static ssize_t srso_show_state(char *buf) { if (boot_cpu_has(X86_FEATURE_SRSO_NO)) - return sysfs_emit(buf, "Not affected\n"); + return sysfs_emit(buf, "Mitigation: SMT disabled\n");
return sysfs_emit(buf, "%s%s\n", srso_strings[srso_mitigation],