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| author | Sami Tolvanen <samitolvanen@google.com> | 2021-04-08 11:28:37 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2021-04-08 16:04:22 -0700 |
| commit | 4ecfca89893843d4ae266485bb878aa760ba82da (patch) | |
| tree | d4f56261e0b9783fd239d6023ea50917bb6ec81a /arch/arm64/include/asm/memory.h | |
| parent | 167d0da23f2422a7986278c1379c472a88186c75 (diff) | |
| download | linux-4ecfca89893843d4ae266485bb878aa760ba82da.tar.bz2 | |
arm64: implement function_nocfi
With CONFIG_CFI_CLANG, the compiler replaces function addresses in
instrumented C code with jump table addresses. This change implements
the function_nocfi() macro, which returns the actual function address
instead.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-13-samitolvanen@google.com
Diffstat (limited to 'arch/arm64/include/asm/memory.h')
| -rw-r--r-- | arch/arm64/include/asm/memory.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 0aabc3be9a75..3a6f9df63606 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -321,6 +321,22 @@ static inline void *phys_to_virt(phys_addr_t x) #define virt_to_pfn(x) __phys_to_pfn(__virt_to_phys((unsigned long)(x))) #define sym_to_pfn(x) __phys_to_pfn(__pa_symbol(x)) +#ifdef CONFIG_CFI_CLANG +/* + * With CONFIG_CFI_CLANG, the compiler replaces function address + * references with the address of the function's CFI jump table + * entry. The function_nocfi macro always returns the address of the + * actual function instead. + */ +#define function_nocfi(x) ({ \ + void *addr; \ + asm("adrp %0, " __stringify(x) "\n\t" \ + "add %0, %0, :lo12:" __stringify(x) \ + : "=r" (addr)); \ + addr; \ +}) +#endif + /* * virt_to_page(x) convert a _valid_ virtual address to struct page * * virt_addr_valid(x) indicates whether a virtual address is valid |