From: Thomas Gleixner <tglx@linutronix.de>
Date: Sat, 27 Jan 2018 15:45:14 +0100
Subject: x86/cpu/bugs: Make retpoline module warning conditional
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Git-commit: e383095c7fe8d218e00ec0f83e4b95ed4e627b02
Patch-mainline: v4.16-rc1
References: bnc#1068032 CVE-2017-5715
If sysfs is disabled and RETPOLINE not defined:
arch/x86/kernel/cpu/bugs.c:97:13: warning: ‘spectre_v2_bad_module’ defined but not used
[-Wunused-variable]
static bool spectre_v2_bad_module;
Hide it.
Fixes: caf7501a1b4e ("module/retpoline: Warn about missing retpoline in module")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
arch/x86/kernel/cpu/bugs.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -93,9 +93,10 @@ static const char *spectre_v2_strings[]
#define pr_fmt(fmt) "Spectre V2 : " fmt
static enum spectre_v2_mitigation spectre_v2_enabled = SPECTRE_V2_NONE;
-static bool spectre_v2_bad_module;
#ifdef RETPOLINE
+static bool spectre_v2_bad_module;
+
bool retpoline_module_ok(bool has_retpoline)
{
if (spectre_v2_enabled == SPECTRE_V2_NONE || has_retpoline)
@@ -105,6 +106,13 @@ bool retpoline_module_ok(bool has_retpol
spectre_v2_bad_module = true;
return false;
}
+
+static inline const char *spectre_v2_module_string(void)
+{
+ return spectre_v2_bad_module ? " - vulnerable module loaded" : "";
+}
+#else
+static inline const char *spectre_v2_module_string(void) { return ""; }
#endif
static void __init spec2_print_if_insecure(const char *reason)
@@ -299,7 +307,7 @@ ssize_t cpu_show_spectre_v2(struct devic
return sprintf(buf, "Not affected\n");
return sprintf(buf, "%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
- boot_cpu_has(X86_FEATURE_IBPB) ? ", IPBP" : "",
- spectre_v2_bad_module ? " - vulnerable module loaded" : "");
+ boot_cpu_has(X86_FEATURE_IBPB) ? ", IBPB" : "",
+ spectre_v2_module_string());
}
#endif