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author | Cyrille Pitchen <cyrille.pitchen@atmel.com> | 2017-02-09 17:51:21 +0100 |
---|---|---|
committer | Herbert Xu <herbert@gondor.apana.org.au> | 2017-02-15 06:23:33 +0100 |
commit | 19998acb0ff67cb8843668f3b94bdbe6018fa7d8 (patch) | |
tree | 30c4a789fee823f608a4496661d05e3094dd955e /drivers | |
parent | crypto: atmel-sha - fix missing "return" instructions (diff) | |
download | linux-19998acb0ff67cb8843668f3b94bdbe6018fa7d8.tar.xz linux-19998acb0ff67cb8843668f3b94bdbe6018fa7d8.zip |
crypto: atmel-sha - fix error management in atmel_sha_start()
This patch clarifies and fixes how errors should be handled by
atmel_sha_start().
For update operations, the previous code wrongly assumed that
(err != -EINPROGRESS) implies (err == 0). It's wrong because that doesn't
take the error cases (err < 0) into account.
This patch also adds many comments to detail all the possible returned
values and what should be done in each case.
Especially, when an error occurs, since atmel_sha_complete() has already
been called, hence releasing the hardware, atmel_sha_start() must not call
atmel_sha_finish_req() later otherwise atmel_sha_complete() would be
called a second time.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/crypto/atmel-sha.c | 27 |
1 files changed, 22 insertions, 5 deletions
diff --git a/drivers/crypto/atmel-sha.c b/drivers/crypto/atmel-sha.c index bc033178d0e7..a9482023d7d3 100644 --- a/drivers/crypto/atmel-sha.c +++ b/drivers/crypto/atmel-sha.c @@ -1106,22 +1106,39 @@ static int atmel_sha_start(struct atmel_sha_dev *dd) ctx->op, req->nbytes); err = atmel_sha_hw_init(dd); - if (err) - goto err1; + return atmel_sha_complete(dd, err); + + /* + * atmel_sha_update_req() and atmel_sha_final_req() can return either: + * -EINPROGRESS: the hardware is busy and the SHA driver will resume + * its job later in the done_task. + * This is the main path. + * + * 0: the SHA driver can continue its job then release the hardware + * later, if needed, with atmel_sha_finish_req(). + * This is the alternate path. + * + * < 0: an error has occurred so atmel_sha_complete(dd, err) has already + * been called, hence the hardware has been released. + * The SHA driver must stop its job without calling + * atmel_sha_finish_req(), otherwise atmel_sha_complete() would be + * called a second time. + * + * Please note that currently, atmel_sha_final_req() never returns 0. + */ dd->resume = atmel_sha_done; if (ctx->op == SHA_OP_UPDATE) { err = atmel_sha_update_req(dd); - if (err != -EINPROGRESS && (ctx->flags & SHA_FLAGS_FINUP)) + if (!err && (ctx->flags & SHA_FLAGS_FINUP)) /* no final() after finup() */ err = atmel_sha_final_req(dd); } else if (ctx->op == SHA_OP_FINAL) { err = atmel_sha_final_req(dd); } -err1: - if (err != -EINPROGRESS) + if (!err) /* done_task will not finish it, so do it here */ atmel_sha_finish_req(req, err); |