redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

crypto: lib/chacha20poly1305 - Set SG_MITER_ATOMIC unconditionally 

There is no reason for the chacha20poly1305 SG miter code to use
kmap instead of kmap_atomic as the critical section doesn't sleep
anyway.  So we can simply get rid of the preemptible check and
set SG_MITER_ATOMIC unconditionally.

Even if we need to reenable preemption to lower latency we should
be doing that by interrupting the SG miter walk rather than using
kmap.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
zero-sugar-mainline-defconfig
Herbert Xu 2020-09-15 13:30:24 +10:00
parent 63cdd870ab
commit 255f6c2e74
1 changed files with 1 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
lib/crypto/chacha20poly1305.c
View File

@ -251,9 +251,7 @@ bool chacha20poly1305_crypt_sg_inplace(struct scatterlist *src,
poly1305_update(&poly1305_state, pad0, 0x10 - (ad_len & 0xf));
}
flags = SG_MITER_TO_SG;
if (!preemptible())
flags |= SG_MITER_ATOMIC;
flags = SG_MITER_TO_SG | SG_MITER_ATOMIC;
sg_miter_start(&miter, src, sg_nents(src), flags);