7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kim Phillips [ Upstream commit 1847c80537891baead3975f3ca969233ff7b2a11 ] When the kernel lacks retpoline support, spectre_v2_select_retpoline() emits "Kernel not compiled with retpoline; no mitigation available!" before returning SPECTRE_V2_NONE to its callers. SPECTRE_V2_NONE is not the final answer, though: spectre_v2_update_mitigation() runs afterwards and can still upgrade the mitigation. On an Intel CPU affected by RETBleed, built with CONFIG_MITIGATION_IBRS_ENTRY=y and CONFIG_MITIGATION_RETPOLINE=n, and booted with spectre_v2=auto, retbleed_select_mitigation() picks RETBLEED_MITIGATION_IBRS, and spectre_v2_update_mitigation() then promotes SPECTRE_V2_NONE to SPECTRE_V2_IBRS. The boot log claims no mitigation is available immediately before reporting "Spectre V2 : Mitigation: IBRS", and sysfs reports the machine as mitigated. The message is alarming and simply wrong. Drop "no mitigation available!" because the final mitigation state is printed afterwards in spectre_v2_update_mitigation() anyway. [ bp: Drop CC:stable, massage commit message. ] Fixes: 480e803dacf8 ("x86/bugs: Restructure spectre_v2 mitigation") Suggested-by: Pawan Gupta Assisted-by: LLM Signed-off-by: Kim Phillips Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Pawan Gupta Link: https://patch.msgid.link/20260831210916.987152-1-kim.phillips@amd.com Signed-off-by: Sasha Levin --- arch/x86/kernel/cpu/bugs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 1b2381da4d831..000ebee2d247b 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1958,7 +1958,7 @@ early_param("spectre_v2", spectre_v2_parse_cmdline); static enum spectre_v2_mitigation __init spectre_v2_select_retpoline(void) { if (!IS_ENABLED(CONFIG_MITIGATION_RETPOLINE)) { - pr_err("Kernel not compiled with retpoline; no mitigation available!"); + pr_err("Kernel not compiled with retpoline"); return SPECTRE_V2_NONE; } -- 2.53.0