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| author | dann frazier <dann.frazier@canonical.com> | 2022-09-06 09:28:22 -0600 |
|---|---|---|
| committer | Peter Jones <pjones@redhat.com> | 2022-10-04 13:53:11 -0400 |
| commit | 5c537b3d0cf8c393dad2e61d49aade68f3af1401 (patch) | |
| tree | 8fefad58abc1d369a75debb0513bab494d7f3a98 /include | |
| parent | 14d63398298c8de23036a4cf61594108b7345863 (diff) | |
| download | efi-boot-shim-5c537b3d0cf8c393dad2e61d49aade68f3af1401.tar.gz efi-boot-shim-5c537b3d0cf8c393dad2e61d49aade68f3af1401.zip | |
shim: Flush the memory region from i-cache before execution
We've seen crashes in early GRUB code on an ARM Cortex-A72-based
platform that point at seemingly harmless instructions. Flushing
the i-cache of those instructions prior to executing has been
shown to avoid the problem, which has parallels with this story:
https://www.mail-archive.com/osv-dev@googlegroups.com/msg06203.html
Add a cache flushing utility function and provide an implementation
using a GCC intrinsic. This will need to be extended to support other
compilers. Note that this intrinsic is a no-op for x86 platforms.
This fixes issue #498.
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/compiler.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/compiler.h b/include/compiler.h index b4bf1031..b0d595f3 100644 --- a/include/compiler.h +++ b/include/compiler.h @@ -192,5 +192,11 @@ */ #define unreachable() __builtin_unreachable() +#if defined(__GNUC__) +#define cache_invalidate(begin, end) __builtin___clear_cache(begin, end) +#else /* __GNUC__ */ +#error shim has no cache_invalidate() implementation for this compiler +#endif /* __GNUC__ */ + #endif /* !COMPILER_H_ */ // vim:fenc=utf-8:tw=75:et |