crypto: sha256 - mark sha256_choose_blocks as __always_inline

From: Arnd Bergmann <[email protected]>

When the compiler chooses to not inline sha256_choose_blocks() in the purgatory code, it fails to link against the missing CPU specific version:

x86_64-linux-ld: arch/x86/purgatory/purgatory.ro: in function `sha256_choose_blocks.part.0':
sha256.c:(.text+0x6a6): undefined reference to irq_fpu_usable' sha256.c:(.text+0x6c7): undefined reference to sha256_blocks_arch' sha256.c:(.text+0x6cc): undefined reference to `sha256_blocks_simd'

Mark this function as __always_inline to prevent this, same as sha256_finup().

---
This is likely compiler specific, I found it in randconfig testing using gcc-9.5 on x86.

---
 include/crypto/internal/sha2.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index b9bccd3ff57f..21a27fd5e198 100644
@@ -25,7 +25,7 @@ void sha256_blocks_arch(u32 state[SHA256_STATE_WORDS],
 void sha256_blocks_simd(u32 state[SHA256_STATE_WORDS],
 			const u8 *data, size_t nblocks);
 
-static inline void sha256_choose_blocks(
+static __always_inline void sha256_choose_blocks(
 	u32 state[SHA256_STATE_WORDS], const u8 *data, size_t nblocks,
 	bool force_generic, bool force_simd)
 {

2.39.5

Thanks, applied to
https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git/log/?h=libcrypto-fixes

I have some additional cleanups to SHA-256 planned, which will supersede the odd sha256_choose_blocks() thing which shouldn't have been pushed out in the first place. For 6.16 I'll take this straightforward fix though.

I don't think the Fixes commit you gave is quite correct. I revised it to:

    Fixes: 5b90a779bc54 ("crypto: lib/sha256 - Add helpers for block-based shash")

I also adjusted the commit title to be consistent with what I'm planning to use for lib/crypto changes:

lib/crypto: sha256: Mark sha256_choose_blocks as __always_inline

Thanks!

- Eric