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fs-verity: use memcpy_from_page()

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Replace extract_hash() with the memcpy_from_page() helper function.

This is simpler, and it has the side effect of replacing the use of
kmap_atomic() with its recommended replacement kmap_local_page().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Link: https://lore.kernel.org/r/20220818223903.43710-1-ebiggers@kernel.org
This commit is contained in:
Eric Biggers 2022-08-18 15:39:03 -07:00
parent 568035b01c
commit c987918a3f
1 changed files with 2 additions and 12 deletions
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14
fs/verity/verify.c
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@ -39,16 +39,6 @@ static void hash_at_level(const struct merkle_tree_params *params,
(params->log_blocksize - params->log_arity);
}
/* Extract a hash from a hash page */
static void extract_hash(struct page *hpage, unsigned int hoffset,
unsigned int hsize, u8 *out)
{
void *virt = kmap_atomic(hpage);
memcpy(out, virt + hoffset, hsize);
kunmap_atomic(virt);
}
static inline int cmp_hashes(const struct fsverity_info *vi,
const u8 *want_hash, const u8 *real_hash,
pgoff_t index, int level)
@ -129,7 +119,7 @@ static bool verify_page(struct inode *inode, const struct fsverity_info *vi,
}
if (PageChecked(hpage)) {
extract_hash(hpage, hoffset, hsize, _want_hash);
memcpy_from_page(_want_hash, hpage, hoffset, hsize);
want_hash = _want_hash;
put_page(hpage);
pr_debug_ratelimited("Hash page already checked, want %s:%*phN\n",
@ -158,7 +148,7 @@ static bool verify_page(struct inode *inode, const struct fsverity_info *vi,
if (err)
goto out;
SetPageChecked(hpage);
extract_hash(hpage, hoffset, hsize, _want_hash);
memcpy_from_page(_want_hash, hpage, hoffset, hsize);
want_hash = _want_hash;
put_page(hpage);
pr_debug("Verified hash page at level %d, now want %s:%*phN\n",