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authorAndi Kleen <ak@linux.intel.com>2018-01-25 15:50:28 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-02-13 12:35:58 +0100
commita1745ad92f50e95b6c2d101cd9b77253969ddccc (patch)
tree12c037a145c0703d8f1d45e9157f5137c37f09d1 /include/linux
parentec86a1dad0c00757ceb49e86b4c10dd7fbc380cb (diff)
module/retpoline: Warn about missing retpoline in module
(cherry picked from commit caf7501a1b4ec964190f31f9c3f163de252273b8) There's a risk that a kernel which has full retpoline mitigations becomes vulnerable when a module gets loaded that hasn't been compiled with the right compiler or the right option. To enable detection of that mismatch at module load time, add a module info string "retpoline" at build time when the module was compiled with retpoline support. This only covers compiled C source, but assembler source or prebuilt object files are not checked. If a retpoline enabled kernel detects a non retpoline protected module at load time, print a warning and report it in the sysfs vulnerability file. [ tglx: Massaged changelog ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: gregkh@linuxfoundation.org Cc: torvalds@linux-foundation.org Cc: jeyu@kernel.org Cc: arjan@linux.intel.com Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/module.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/module.h b/include/linux/module.h
index 0c3207d26ac0..d2224a09b4b5 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -791,6 +791,15 @@ 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)
{