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| author | Sami Tolvanen <samitolvanen@google.com> | 2021-04-08 11:28:29 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2021-04-08 16:04:21 -0700 |
| commit | 28aad1c29053195b1a9f56742e64b679d61e786b (patch) | |
| tree | c7dd2f2c34527aa58d4cac71d337fed7af8f0fce /scripts/module.lds.S | |
| parent | 5caf968262df0ec7a3377fb67d4a6bfa979cb028 (diff) | |
| download | linux-28aad1c29053195b1a9f56742e64b679d61e786b.tar.gz linux-28aad1c29053195b1a9f56742e64b679d61e786b.tar.bz2 linux-28aad1c29053195b1a9f56742e64b679d61e786b.zip | |
module: ensure __cfi_check alignment
CONFIG_CFI_CLANG_SHADOW assumes the __cfi_check() function is page
aligned and at the beginning of the .text section. While Clang would
normally align the function correctly, it fails to do so for modules
with no executable code.
This change ensures the correct __cfi_check() location and
alignment. It also discards the .eh_frame section, which Clang can
generate with certain sanitizers, such as CFI.
Link: https://bugs.llvm.org/show_bug.cgi?id=46293
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-5-samitolvanen@google.com
Diffstat (limited to 'scripts/module.lds.S')
| -rw-r--r-- | scripts/module.lds.S | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/scripts/module.lds.S b/scripts/module.lds.S index 2c52535f9b56..04c5685c25cf 100644 --- a/scripts/module.lds.S +++ b/scripts/module.lds.S @@ -3,10 +3,20 @@ * Archs are free to supply their own linker scripts. ld will * combine them automatically. */ +#ifdef CONFIG_CFI_CLANG +# include <asm/page.h> +# define ALIGN_CFI ALIGN(PAGE_SIZE) +# define SANITIZER_DISCARDS *(.eh_frame) +#else +# define ALIGN_CFI +# define SANITIZER_DISCARDS +#endif + SECTIONS { /DISCARD/ : { *(.discard) *(.discard.*) + SANITIZER_DISCARDS } __ksymtab 0 : { *(SORT(___ksymtab+*)) } @@ -41,7 +51,14 @@ SECTIONS { *(.rodata..L*) } - .text : { *(.text .text.[0-9a-zA-Z_]*) } + /* + * With CONFIG_CFI_CLANG, we assume __cfi_check is at the beginning + * of the .text section, and is aligned to PAGE_SIZE. + */ + .text : ALIGN_CFI { + *(.text.__cfi_check) + *(.text .text.[0-9a-zA-Z_]* .text..L.cfi*) + } #endif } |