kernel/linux.git/crypto/scatterwalk.c, branch v6.19.11

Revert "crypto: scatterwalk - Move skcipher walk and use it for memcpy_sglist"

2025-11-22T02:04:50+00:00

This reverts commit 0f8d42bf128d349ad490e87d5574d211245e40f1, with the memcpy_sglist() part dropped. Now that memcpy_sglist() no longer uses the skcipher_walk code, the skcipher_walk code can be moved back to where it belongs. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: scatterwalk - Fix memcpy_sglist() to always succeed

2025-11-22T02:04:50+00:00

The original implementation of memcpy_sglist() was broken because it didn't handle scatterlists that describe exactly the same memory, which is a case that many callers rely on. The current implementation is broken too because it calls the skcipher_walk functions which can fail. It ignores any errors from those functions. Fix it by replacing it with a new implementation written from scratch. It always succeeds. It's also a bit faster, since it avoids the overhead of skcipher_walk. skcipher_walk includes a lot of functionality (such as alignmask handling) that's irrelevant here. Reported-by: Colin Ian King Closes: https://lore.kernel.org/r/20251114122620.111623-1-coking@nvidia.com Fixes: 131bdceca1f0 ("crypto: scatterwalk - Add memcpy_sglist") Fixes: 0f8d42bf128d ("crypto: scatterwalk - Move skcipher walk and use it for memcpy_sglist") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: scatterwalk - Move skcipher walk and use it for memcpy_sglist

2025-04-28T11:45:26+00:00

Move the generic part of skcipher walk into scatterwalk, and use it to implement memcpy_sglist. This makes memcpy_sglist do the right thing when two distinct SG lists contain identical subsets (e.g., the AD part of AEAD). Signed-off-by: Herbert Xu

crypto: scatterwalk - Add memcpy_sglist

2025-03-15T08:21:22+00:00

Add memcpy_sglist which copies one SG list to another. Signed-off-by: Herbert Xu

crypto: scatterwalk - Change scatterwalk_next calling convention

2025-03-15T08:21:22+00:00

Rather than returning the address and storing the length into an argument pointer, add an address field to the walk struct and use that to store the address. The length is returned directly. Change the done functions to use this stored address instead of getting them from the caller. Split the address into two using a union. The user should only access the const version so that it is never changed. Signed-off-by: Herbert Xu

crypto: scatterwalk - remove obsolete functions

2025-03-02T07:19:44+00:00

Remove various functions that are no longer used. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: scatterwalk - add new functions for copying data

2025-03-02T07:19:43+00:00

Add memcpy_from_sglist() and memcpy_to_sglist() which are more readable versions of scatterwalk_map_and_copy() with the 'out' argument 0 and 1 respectively. They follow the same argument order as memcpy_from_page() and memcpy_to_page() from . Note that in the case of memcpy_from_sglist(), this also happens to be the same argument order that scatterwalk_map_and_copy() uses. The new code is also faster, mainly because it builds the scatter_walk directly without creating a temporary scatterlist. E.g., a 20% performance improvement is seen for copying the AES-GCM auth tag. Make scatterwalk_map_and_copy() be a wrapper around memcpy_from_sglist() and memcpy_to_sglist(). Callers of scatterwalk_map_and_copy() should be updated to call memcpy_from_sglist() or memcpy_to_sglist() directly, but there are a lot of them so they aren't all being updated right away. Also add functions memcpy_from_scatterwalk() and memcpy_to_scatterwalk() which are similar but operate on a scatter_walk instead of a scatterlist. These will replace scatterwalk_copychunks() with the 'out' argument 0 and 1 respectively. Their behavior differs slightly from scatterwalk_copychunks() in that they automatically take care of flushing the dcache when needed, making them easier to use. scatterwalk_copychunks() itself is left unchanged for now. It will be removed after its callers are updated to use other functions instead. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: scatterwalk - add new functions for skipping data

2025-03-02T07:19:43+00:00

Add scatterwalk_skip() to skip the given number of bytes in a scatter_walk. Previously support for skipping was provided through scatterwalk_copychunks(..., 2) followed by scatterwalk_done(), which was confusing and less efficient. Also add scatterwalk_start_at_pos() which starts a scatter_walk at the given position, equivalent to scatterwalk_start() + scatterwalk_skip(). This addresses another common need in a more streamlined way. Later patches will convert various users to use these functions. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

crypto: scatterwalk - remove 'chain' argument from scatterwalk_crypto_chain()

2018-08-03T10:06:03+00:00

All callers pass chain=0 to scatterwalk_crypto_chain(). Remove this unneeded parameter. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu