----- Ursprüngliche Mail -----
> Von: "Sean Anderson" <sean.anderson@xxxxxxxx>
> An: "Linux Crypto Mailing List" <linux-crypto@xxxxxxxxxxxxxxx>, "Herbert Xu" <herbert@xxxxxxxxxxxxxxxxxxx>, "davem"
> <davem@xxxxxxxxxxxxx>
> CC: "horia geanta" <horia.geanta@xxxxxxx>, "aymen sghaier" <aymen.sghaier@xxxxxxx>, "richard" <richard@xxxxxx>,
> "linux-arm-kernel" <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>, "Marek Vasut" <marex@xxxxxxx>, "Sean Anderson"
> <sean.anderson@xxxxxxxx>
> Gesendet: Donnerstag, 1. Juli 2021 20:56:38
> Betreff: [PATCH v2 2/2] crypto: mxs_dcp: Use sg_mapping_iter to copy data
> This uses the sg_miter_*() functions to copy data, instead of doing it
> ourselves. Using sg_copy_buffer() would be better, but this way we don't
> have to keep traversing the beginning of the scatterlist every time we
> do another copy.
Huh? This does not match the code.
You use sg_pcopy_from_buffer() which is just a wrapper around sg_copy_buffer().
Did you forget to update the commit message? :-)
> In addition to reducing code size, this fixes the following oops
> resulting from failing to kmap the page:
>
> [ 68.896381] Unable to handle kernel NULL pointer dereference at virtual
> address 00000ab8
> [ 68.904539] pgd = 3561adb3
> [ 68.907475] [00000ab8] *pgd=00000000
> [ 68.911153] Internal error: Oops: 805 [#1] ARM
> [ 68.915618] Modules linked in: cfg80211 rfkill des_generic libdes arc4
> libarc4 cbc ecb algif_skcipher sha256_generic libsha256 sha1_generic hmac
> aes_generic libaes cmac sha512_generic md5 md4 algif_hash af_alg i2c_imx
> i2c_core ci_hdrc_imx ci_hdrc mxs_dcp ulpi roles udc_core imx_sdma usbmisc_imx
> usb_common firmware_class virt_dma phy_mxs_usb nf_tables nfnetlink ip_tables
> x_tables ipv6 autofs4
> [ 68.950741] CPU: 0 PID: 139 Comm: mxs_dcp_chan/ae Not tainted 5.10.34 #296
> [ 68.958501] Hardware name: Freescale i.MX6 Ultralite (Device Tree)
> [ 68.964710] PC is at memcpy+0xa8/0x330
> [ 68.968479] LR is at 0xd7b2bc9d
> [ 68.971638] pc : [<c053e7c8>] lr : [<d7b2bc9d>] psr: 000f0013
> [ 68.977920] sp : c2cbbee4 ip : 00000010 fp : 00000010
> [ 68.983159] r10: 00000000 r9 : c3283a40 r8 : 1a5a6f08
> [ 68.988402] r7 : 4bfe0ecc r6 : 76d8a220 r5 : c32f9050 r4 : 00000001
> [ 68.994945] r3 : 00000ab8 r2 : fffffff0 r1 : c32f9050 r0 : 00000ab8
> [ 69.001492] Flags: nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
> [ 69.008646] Control: 10c53c7d Table: 83664059 DAC: 00000051
> [ 69.014414] Process mxs_dcp_chan/ae (pid: 139, stack limit = 0x667b57ab)
> [ 69.021133] Stack: (0xc2cbbee4 to 0xc2cbc000)
> [ 69.025519] bee0: c32f9050 c3235408 00000010 00000010 00000ab8
> 00000001 bf10406c
> [ 69.033720] bf00: 00000000 00000000 00000010 00000000 c32355d0 832fb080
> 00000000 c13de2fc
> [ 69.041921] bf20: c3628010 00000010 c33d5780 00000ab8 bf1067e8 00000002
> c21e5010 c2cba000
> [ 69.050125] bf40: c32f8040 00000000 bf106a40 c32f9040 c3283a80 00000001
> bf105240 c3234040
> [ 69.058327] bf60: ffffe000 c3204100 c2c69800 c2cba000 00000000 bf103b84
> 00000000 c2eddc54
> [ 69.066530] bf80: c3204144 c0140d1c c2cba000 c2c69800 c0140be8 00000000
> 00000000 00000000
> [ 69.074730] bfa0: 00000000 00000000 00000000 c0100114 00000000 00000000
> 00000000 00000000
> [ 69.082932] bfc0: 00000000 00000000 00000000 00000000 00000000 00000000
> 00000000 00000000
> [ 69.091131] bfe0: 00000000 00000000 00000000 00000000 00000013 00000000
> 00000000 00000000
> [ 69.099364] [<c053e7c8>] (memcpy) from [<bf10406c>]
> (dcp_chan_thread_aes+0x4e8/0x840 [mxs_dcp])
> [ 69.108117] [<bf10406c>] (dcp_chan_thread_aes [mxs_dcp]) from [<c0140d1c>]
> (kthread+0x134/0x160)
> [ 69.116941] [<c0140d1c>] (kthread) from [<c0100114>]
> (ret_from_fork+0x14/0x20)
> [ 69.124178] Exception stack(0xc2cbbfb0 to 0xc2cbbff8)
> [ 69.129250] bfa0: 00000000 00000000
> 00000000 00000000
> [ 69.137450] bfc0: 00000000 00000000 00000000 00000000 00000000 00000000
> 00000000 00000000
> [ 69.145648] bfe0: 00000000 00000000 00000000 00000000 00000013 00000000
> [ 69.152289] Code: e320f000 e4803004 e4804004 e4805004 (e4806004)
>
> Signed-off-by: Sean Anderson <sean.anderson@xxxxxxxx>
> ---
>
> Changes in v2:
> - Fix warning when taking the minimum of a u32 and a size_t
> - Use sg_pcopy_from_buffer to properly deal with partial reads.
>
> drivers/crypto/mxs-dcp.c | 36 +++++++++---------------------------
> 1 file changed, 9 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/crypto/mxs-dcp.c b/drivers/crypto/mxs-dcp.c
> index f397cc5bf102..d19e5ffb5104 100644
> --- a/drivers/crypto/mxs-dcp.c
> +++ b/drivers/crypto/mxs-dcp.c
> @@ -300,21 +300,20 @@ static int mxs_dcp_aes_block_crypt(struct
> crypto_async_request *arq)
>
> struct scatterlist *dst = req->dst;
> struct scatterlist *src = req->src;
> - const int nents = sg_nents(req->src);
> + int dst_nents = sg_nents(dst);
>
> const int out_off = DCP_BUF_SZ;
> uint8_t *in_buf = sdcp->coh->aes_in_buf;
> uint8_t *out_buf = sdcp->coh->aes_out_buf;
>
> - uint8_t *out_tmp, *src_buf, *dst_buf = NULL;
> uint32_t dst_off = 0;
> + uint8_t *src_buf = NULL;
> uint32_t last_out_len = 0;
>
> uint8_t *key = sdcp->coh->aes_key;
>
> int ret = 0;
> - int split = 0;
> - unsigned int i, len, clen, rem = 0, tlen = 0;
> + unsigned int i, len, clen, tlen = 0;
> int init = 0;
> bool limit_hit = false;
>
> @@ -332,7 +331,7 @@ static int mxs_dcp_aes_block_crypt(struct
> crypto_async_request *arq)
> memset(key + AES_KEYSIZE_128, 0, AES_KEYSIZE_128);
> }
>
> - for_each_sg(req->src, src, nents, i) {
> + for_each_sg(req->src, src, sg_nents(src), i) {
> src_buf = sg_virt(src);
> len = sg_dma_len(src);
> tlen += len;
> @@ -357,34 +356,17 @@ static int mxs_dcp_aes_block_crypt(struct
> crypto_async_request *arq)
> * submit the buffer.
> */
> if (actx->fill == out_off || sg_is_last(src) ||
> - limit_hit) {
> + limit_hit) {
> ret = mxs_dcp_run_aes(actx, req, init);
> if (ret)
> return ret;
> init = 0;
>
> - out_tmp = out_buf;
> + sg_pcopy_from_buffer(dst, dst_nents, out_buf,
> + actx->fill, dst_off);
> + dst_off += actx->fill;
> last_out_len = actx->fill;
> - while (dst && actx->fill) {
> - if (!split) {
> - dst_buf = sg_virt(dst);
> - dst_off = 0;
> - }
> - rem = min(sg_dma_len(dst) - dst_off,
> - actx->fill);
> -
> - memcpy(dst_buf + dst_off, out_tmp, rem);
> - out_tmp += rem;
> - dst_off += rem;
> - actx->fill -= rem;
> -
> - if (dst_off == sg_dma_len(dst)) {
> - dst = sg_next(dst);
> - split = 0;
> - } else {
> - split = 1;
> - }
> - }
> + actx->fill = 0;
> }
> } while (len);
>
> --
> 2.25.1
