On Fri, Nov 18, 2022 at 03:43:55PM +0000, Elliott, Robert (Servers) wrote: > > > -----Original Message----- > > From: Eric Biggers <ebiggers@xxxxxxxxxx> > > Sent: Friday, November 18, 2022 3:02 AM > > To: linux-crypto@xxxxxxxxxxxxxxx > > Cc: x86@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; Sami Tolvanen > > <samitolvanen@xxxxxxxxxx> > > Subject: [PATCH 0/11] crypto: CFI fixes > > > > This series fixes some crashes when CONFIG_CFI_CLANG (Control Flow > > Integrity) is enabled, with the new CFI implementation that was merged > > in 6.1 and is supported on x86. Some of them were unconditional > > crashes, while others depended on whether the compiler optimized out the > > indirect calls or not. This series also simplifies some code that was > > intended to work around limitations of the old CFI implementation and is > > unnecessary for the new CFI implementation. > > Some of the x86 modules EXPORT their asm functions. Does that leave them > at risk of being called indirectly? > > arch/x86/crypto/camellia-aesni-avx-asm_64.S:SYM_FUNC_START(camellia_ecb_dec_16way) > arch/x86/crypto/camellia-aesni-avx-asm_64.S:SYM_FUNC_START(camellia_ecb_enc_16way) > arch/x86/crypto/camellia-aesni-avx-asm_64.S:SYM_FUNC_START(camellia_cbc_dec_16way) > arch/x86/crypto/camellia_aesni_avx_glue.c:asmlinkage void camellia_ecb_enc_16way(const void *ctx, u8 *dst, const u8 *src); > arch/x86/crypto/camellia_aesni_avx_glue.c:EXPORT_SYMBOL_GPL(camellia_ecb_enc_16way); > arch/x86/crypto/camellia_aesni_avx_glue.c:asmlinkage void camellia_ecb_dec_16way(const void *ctx, u8 *dst, const u8 *src); > arch/x86/crypto/camellia_aesni_avx_glue.c:EXPORT_SYMBOL_GPL(camellia_ecb_dec_16way); > arch/x86/crypto/camellia_aesni_avx_glue.c:asmlinkage void camellia_cbc_dec_16way(const void *ctx, u8 *dst, const u8 *src); > arch/x86/crypto/camellia_aesni_avx_glue.c:EXPORT_SYMBOL_GPL(camellia_cbc_dec_16way); > > arch/x86/crypto/twofish-x86_64-asm_64-3way.S:SYM_FUNC_START(__twofish_enc_blk_3way) > arch/x86/crypto/twofish.h:asmlinkage void __twofish_enc_blk_3way(const void *ctx, u8 *dst, const u8 *src, > arch/x86/crypto/twofish_glue_3way.c:EXPORT_SYMBOL_GPL(__twofish_enc_blk_3way); No, that doesn't matter at all. Whether a symbol is exported or not just has to do with how the code is divided into modules. It doesn't have anything to do with indirect calls. > A few of the x86 asm functions used by C code are not referenced with > asmlinkage like all the others. They're not EXPORTed, though, so whether > they're indirectly used can be determined. > > u32 crc32_pclmul_le_16(unsigned char const *buffer, size_t len, u32 crc32); > > void clmul_ghash_mul(char *dst, const u128 *shash); > > void clmul_ghash_update(char *dst, const char *src, unsigned int srclen, > const u128 *shash); No, the above functions are only called directly. I did do another search and found that some of the sm4 functions are called indirectly, though, so I'll send out an updated patchset that fixes those too. - Eric
