From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read The buffered read collector zero-fills the tail of a short read that stops below the inode's i_size (netfs_clear_unread()), so a read that races an extending write still returns the expected number of bytes. The non-buffered collector path does no such thing: it just records how much was transferred. Add the same zero-fill for the non-buffered case, gated on NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short result from it is known to be safe to treat as a hole, as opposed to NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of the file and should be reported short as-is. Only CLEAR_TAIL should zero-fill here; a real EOF must stay a real short read. No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest, so this is inert on its own -- a following change teaches cifs to set it in the one case that needs it. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Reviewed-by: David Howells Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- include/crypto/internal/simd.h | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 include/crypto/internal/simd.h (limited to 'include/crypto/internal/simd.h') diff --git a/include/crypto/internal/simd.h b/include/crypto/internal/simd.h new file mode 100644 index 000000000..f5e5d7b63 --- /dev/null +++ b/include/crypto/internal/simd.h @@ -0,0 +1,40 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Shared crypto simd helpers + */ + +#ifndef _CRYPTO_INTERNAL_SIMD_H +#define _CRYPTO_INTERNAL_SIMD_H + +#include +#include +#include + +struct simd_aead_alg; +struct aead_alg; + +int simd_register_aeads_compat(struct aead_alg *algs, int count, + struct simd_aead_alg **simd_algs); + +void simd_unregister_aeads(struct aead_alg *algs, int count, + struct simd_aead_alg **simd_algs); + +/* + * crypto_simd_usable() - is it allowed at this time to use SIMD instructions or + * access the SIMD register file? + * + * This delegates to may_use_simd(), except that this also returns false if SIMD + * in crypto code has been temporarily disabled on this CPU by the crypto + * self-tests, in order to test the no-SIMD fallback code. This override is + * currently limited to configurations where the "full" self-tests are enabled, + * because it might be a bit too invasive to be part of the "fast" self-tests. + */ +#ifdef CONFIG_CRYPTO_SELFTESTS_FULL +DECLARE_PER_CPU(bool, crypto_simd_disabled_for_test); +#define crypto_simd_usable() \ + (may_use_simd() && !this_cpu_read(crypto_simd_disabled_for_test)) +#else +#define crypto_simd_usable() may_use_simd() +#endif + +#endif /* _CRYPTO_INTERNAL_SIMD_H */ -- cgit v1.3.1