linux/drivers/crypto/omap-crypto.c
Tero Kristo 839bb2a9ca crypto: omap-crypto - copy the temporary data to output buffer properly
Both source and destination are scatterlists that can contain multiple
entries under the omap crypto cleanup handling. Current code only copies
data from the first source scatterlist entry to the target scatterlist,
potentially omitting any sg entries following the first one. Instead,
implement a new routine that walks through both source and target and
copies the data over once it goes.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-12-11 16:37:00 +08:00

221 lines
4.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* OMAP Crypto driver common support routines.
*
* Copyright (c) 2017 Texas Instruments Incorporated
* Tero Kristo <t-kristo@ti.com>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/scatterlist.h>
#include <crypto/scatterwalk.h>
#include "omap-crypto.h"
static int omap_crypto_copy_sg_lists(int total, int bs,
struct scatterlist **sg,
struct scatterlist *new_sg, u16 flags)
{
int n = sg_nents(*sg);
struct scatterlist *tmp;
if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY)) {
new_sg = kmalloc_array(n, sizeof(*sg), GFP_KERNEL);
if (!new_sg)
return -ENOMEM;
sg_init_table(new_sg, n);
}
tmp = new_sg;
while (*sg && total) {
int len = (*sg)->length;
if (total < len)
len = total;
if (len > 0) {
total -= len;
sg_set_page(tmp, sg_page(*sg), len, (*sg)->offset);
if (total <= 0)
sg_mark_end(tmp);
tmp = sg_next(tmp);
}
*sg = sg_next(*sg);
}
*sg = new_sg;
return 0;
}
static int omap_crypto_copy_sgs(int total, int bs, struct scatterlist **sg,
struct scatterlist *new_sg, u16 flags)
{
void *buf;
int pages;
int new_len;
new_len = ALIGN(total, bs);
pages = get_order(new_len);
buf = (void *)__get_free_pages(GFP_ATOMIC, pages);
if (!buf) {
pr_err("%s: Couldn't allocate pages for unaligned cases.\n",
__func__);
return -ENOMEM;
}
if (flags & OMAP_CRYPTO_COPY_DATA) {
scatterwalk_map_and_copy(buf, *sg, 0, total, 0);
if (flags & OMAP_CRYPTO_ZERO_BUF)
memset(buf + total, 0, new_len - total);
}
if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY))
sg_init_table(new_sg, 1);
sg_set_buf(new_sg, buf, new_len);
*sg = new_sg;
return 0;
}
static int omap_crypto_check_sg(struct scatterlist *sg, int total, int bs,
u16 flags)
{
int len = 0;
int num_sg = 0;
if (!IS_ALIGNED(total, bs))
return OMAP_CRYPTO_NOT_ALIGNED;
while (sg) {
num_sg++;
if (!IS_ALIGNED(sg->offset, 4))
return OMAP_CRYPTO_NOT_ALIGNED;
if (!IS_ALIGNED(sg->length, bs))
return OMAP_CRYPTO_NOT_ALIGNED;
#ifdef CONFIG_ZONE_DMA
if (page_zonenum(sg_page(sg)) != ZONE_DMA)
return OMAP_CRYPTO_NOT_ALIGNED;
#endif
len += sg->length;
sg = sg_next(sg);
if (len >= total)
break;
}
if ((flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) && num_sg > 1)
return OMAP_CRYPTO_NOT_ALIGNED;
if (len != total)
return OMAP_CRYPTO_BAD_DATA_LENGTH;
return 0;
}
int omap_crypto_align_sg(struct scatterlist **sg, int total, int bs,
struct scatterlist *new_sg, u16 flags,
u8 flags_shift, unsigned long *dd_flags)
{
int ret;
*dd_flags &= ~(OMAP_CRYPTO_COPY_MASK << flags_shift);
if (flags & OMAP_CRYPTO_FORCE_COPY)
ret = OMAP_CRYPTO_NOT_ALIGNED;
else
ret = omap_crypto_check_sg(*sg, total, bs, flags);
if (ret == OMAP_CRYPTO_NOT_ALIGNED) {
ret = omap_crypto_copy_sgs(total, bs, sg, new_sg, flags);
if (ret)
return ret;
*dd_flags |= OMAP_CRYPTO_DATA_COPIED << flags_shift;
} else if (ret == OMAP_CRYPTO_BAD_DATA_LENGTH) {
ret = omap_crypto_copy_sg_lists(total, bs, sg, new_sg, flags);
if (ret)
return ret;
if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY))
*dd_flags |= OMAP_CRYPTO_SG_COPIED << flags_shift;
} else if (flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) {
sg_set_buf(new_sg, sg_virt(*sg), (*sg)->length);
}
return 0;
}
EXPORT_SYMBOL_GPL(omap_crypto_align_sg);
static void omap_crypto_copy_data(struct scatterlist *src,
struct scatterlist *dst,
int offset, int len)
{
int amt;
void *srcb, *dstb;
int srco = 0, dsto = offset;
while (src && dst && len) {
if (srco >= src->length) {
srco -= src->length;
src = sg_next(src);
continue;
}
if (dsto >= dst->length) {
dsto -= dst->length;
dst = sg_next(dst);
continue;
}
amt = min(src->length - srco, dst->length - dsto);
amt = min(len, amt);
srcb = sg_virt(src) + srco;
dstb = sg_virt(dst) + dsto;
memcpy(dstb, srcb, amt);
srco += amt;
dsto += amt;
len -= amt;
}
}
void omap_crypto_cleanup(struct scatterlist *sg, struct scatterlist *orig,
int offset, int len, u8 flags_shift,
unsigned long flags)
{
void *buf;
int pages;
flags >>= flags_shift;
flags &= OMAP_CRYPTO_COPY_MASK;
if (!flags)
return;
buf = sg_virt(sg);
pages = get_order(len);
if (orig && (flags & OMAP_CRYPTO_COPY_MASK))
omap_crypto_copy_data(sg, orig, offset, len);
if (flags & OMAP_CRYPTO_DATA_COPIED)
free_pages((unsigned long)buf, pages);
else if (flags & OMAP_CRYPTO_SG_COPIED)
kfree(sg);
}
EXPORT_SYMBOL_GPL(omap_crypto_cleanup);
MODULE_DESCRIPTION("OMAP crypto support library.");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Tero Kristo <t-kristo@ti.com>");