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-rw-r--r--arch/x86/kernel/cpu/bugs.c17
-rw-r--r--include/linux/module.h9
-rw-r--r--kernel/module.c11
-rw-r--r--scripts/mod/modpost.c9
4 files changed, 45 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 390b3dc..4a39d7b 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -11,6 +11,7 @@
#include <linux/init.h>
#include <linux/utsname.h>
#include <linux/cpu.h>
+#include <linux/module.h>
#include <asm/nospec-branch.h>
#include <asm/cmdline.h>
@@ -93,6 +94,19 @@ static const char *spectre_v2_strings[] = {
#define pr_fmt(fmt) "Spectre V2 mitigation: " fmt
static enum spectre_v2_mitigation spectre_v2_enabled = SPECTRE_V2_NONE;
+static bool spectre_v2_bad_module;
+
+#ifdef RETPOLINE
+bool retpoline_module_ok(bool has_retpoline)
+{
+ if (spectre_v2_enabled == SPECTRE_V2_NONE || has_retpoline)
+ return true;
+
+ pr_err("System may be vunerable to spectre v2\n");
+ spectre_v2_bad_module = true;
+ return false;
+}
+#endif
static void __init spec2_print_if_insecure(const char *reason)
{
@@ -278,6 +292,7 @@ ssize_t cpu_show_spectre_v2(struct device *dev,
if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
return sprintf(buf, "Not affected\n");
- return sprintf(buf, "%s\n", spectre_v2_strings[spectre_v2_enabled]);
+ return sprintf(buf, "%s%s\n", spectre_v2_strings[spectre_v2_enabled],
+ spectre_v2_bad_module ? " - vulnerable module loaded" : "");
}
#endif
diff --git a/include/linux/module.h b/include/linux/module.h
index fe5aa37..b1cc541 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -794,6 +794,15 @@ static inline void module_bug_finalize(const Elf_Ehdr *hdr,
static inline void module_bug_cleanup(struct module *mod) {}
#endif /* CONFIG_GENERIC_BUG */
+#ifdef RETPOLINE
+extern bool retpoline_module_ok(bool has_retpoline);
+#else
+static inline bool retpoline_module_ok(bool has_retpoline)
+{
+ return true;
+}
+#endif
+
#ifdef CONFIG_MODULE_SIG
static inline bool module_sig_ok(struct module *module)
{
diff --git a/kernel/module.c b/kernel/module.c
index de66ec8..690c065 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2855,6 +2855,15 @@ static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
}
#endif /* CONFIG_LIVEPATCH */
+static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
+{
+ if (retpoline_module_ok(get_modinfo(info, "retpoline")))
+ return;
+
+ pr_warn("%s: loading module not compiled with retpoline compiler.\n",
+ mod->name);
+}
+
/* Sets info->hdr and info->len. */
static int copy_module_from_user(const void __user *umod, unsigned long len,
struct load_info *info)
@@ -3021,6 +3030,8 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags)
add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
}
+ check_modinfo_retpoline(mod, info);
+
if (get_modinfo(info, "staging")) {
add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
pr_warn("%s: module is from the staging directory, the quality "
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 98314b4..54deaa1 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2165,6 +2165,14 @@ static void add_intree_flag(struct buffer *b, int is_intree)
buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
}
+/* Cannot check for assembler */
+static void add_retpoline(struct buffer *b)
+{
+ buf_printf(b, "\n#ifdef RETPOLINE\n");
+ buf_printf(b, "MODULE_INFO(retpoline, \"Y\");\n");
+ buf_printf(b, "#endif\n");
+}
+
static void add_staging_flag(struct buffer *b, const char *name)
{
static const char *staging_dir = "drivers/staging";
@@ -2506,6 +2514,7 @@ int main(int argc, char **argv)
err |= check_modname_len(mod);
add_header(&buf, mod);
add_intree_flag(&buf, !external_module);
+ add_retpoline(&buf);
add_staging_flag(&buf, mod->name);
err |= add_versions(&buf, mod);
add_depends(&buf, mod, modules);
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