[PATCH 2/3] driver core: cpu: Unify redundant silly stubs

From: Borislav Petkov
Date: Wed Aug 09 2023 - 06:27:45 EST


From: "Borislav Petkov (AMD)" <bp@xxxxxxxxx>

Make them all a weak function, aliasing to a single function which
issues the "Not affected" string.

No functional changes.

Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
---
drivers/base/cpu.c | 86 ++++++++++------------------------------------
1 file changed, 18 insertions(+), 68 deletions(-)

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 52df435eecf8..971771347aa6 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -509,79 +509,29 @@ static void __init cpu_dev_register_generic(void)
}

#ifdef CONFIG_GENERIC_CPU_VULNERABILITIES
-
-ssize_t __weak cpu_show_meltdown(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return sysfs_emit(buf, "Not affected\n");
-}
-
-ssize_t __weak cpu_show_spectre_v1(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return sysfs_emit(buf, "Not affected\n");
-}
-
-ssize_t __weak cpu_show_spectre_v2(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return sysfs_emit(buf, "Not affected\n");
-}
-
-ssize_t __weak cpu_show_spec_store_bypass(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return sysfs_emit(buf, "Not affected\n");
-}
-
-ssize_t __weak cpu_show_l1tf(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return sysfs_emit(buf, "Not affected\n");
-}
-
-ssize_t __weak cpu_show_mds(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return sysfs_emit(buf, "Not affected\n");
-}
-
-ssize_t __weak cpu_show_tsx_async_abort(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- return sysfs_emit(buf, "Not affected\n");
-}
-
-ssize_t __weak cpu_show_itlb_multihit(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return sysfs_emit(buf, "Not affected\n");
-}
-
-ssize_t __weak cpu_show_srbds(struct device *dev,
+ssize_t cpu_show_not_affected(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sysfs_emit(buf, "Not affected\n");
}

-ssize_t __weak cpu_show_mmio_stale_data(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return sysfs_emit(buf, "Not affected\n");
-}
-
-ssize_t __weak cpu_show_retbleed(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return sysfs_emit(buf, "Not affected\n");
-}
-
-ssize_t __weak cpu_show_spec_rstack_overflow(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return sysfs_emit(buf, "Not affected\n");
-}
+#define CPU_VULN_FALLBACK(func) \
+ ssize_t cpu_show_##func(struct device *, \
+ struct device_attribute *, char *) \
+ __attribute__((weak, alias("cpu_show_not_affected")))
+
+CPU_VULN_FALLBACK(meltdown);
+CPU_VULN_FALLBACK(spectre_v1);
+CPU_VULN_FALLBACK(spectre_v2);
+CPU_VULN_FALLBACK(spec_store_bypass);
+CPU_VULN_FALLBACK(l1tf);
+CPU_VULN_FALLBACK(mds);
+CPU_VULN_FALLBACK(tsx_async_abort);
+CPU_VULN_FALLBACK(itlb_multihit);
+CPU_VULN_FALLBACK(srbds);
+CPU_VULN_FALLBACK(mmio_stale_data);
+CPU_VULN_FALLBACK(retbleed);
+CPU_VULN_FALLBACK(spec_rstack_overflow);

ssize_t __weak cpu_show_gds(struct device *dev,
struct device_attribute *attr, char *buf)
--
2.41.0