diff options
| author | Andi Kleen <ak@linux.intel.com> | 2018-01-26 00:50:28 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-01-26 15:03:56 +0100 |
| commit | caf7501a1b4ec964190f31f9c3f163de252273b8 (patch) | |
| tree | f626e796eb8f30eca268595ca07dc90e00b06ec3 /include | |
| parent | KVM: VMX: Make indirect call speculation safe (diff) | |
| download | linux-caf7501a1b4ec964190f31f9c3f163de252273b8.tar.xz linux-caf7501a1b4ec964190f31f9c3f163de252273b8.zip | |
module/retpoline: Warn about missing retpoline in module
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
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/module.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/module.h b/include/linux/module.h index fe5aa3736707..b1cc541f2ddf 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) { |