@@ -21,6 +21,7 @@
#include <linux/bitops.h>
#include <linux/count_zeros.h>
#include <linux/byteorder/generic.h>
+#include <linux/scatterlist.h>
#include <linux/string.h>
#include "mpi-internal.h"
@@ -255,7 +256,9 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned nbytes,
#error please implement for this limb size.
#endif
unsigned int n = mpi_get_size(a);
+ struct sg_mapping_iter miter;
int i, x, buf_len;
+ int nents;
if (sign)
*sign = a->sign;
@@ -263,23 +266,27 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned nbytes,
if (nbytes < n)
return -EOVERFLOW;
- buf_len = sgl->length;
- p2 = sg_virt(sgl);
+ nents = sg_nents_for_len(sgl, nbytes);
+ if (nents < 0)
+ return -EINVAL;
- while (nbytes > n) {
- if (!buf_len) {
- sgl = sg_next(sgl);
- if (!sgl)
- return -EINVAL;
- buf_len = sgl->length;
- p2 = sg_virt(sgl);
- }
+ sg_miter_start(&miter, sgl, nents, SG_MITER_ATOMIC | SG_MITER_TO_SG);
+ sg_miter_next(&miter);
+ buf_len = miter.length;
+ p2 = miter.addr;
+ while (nbytes > n) {
i = min_t(unsigned, nbytes - n, buf_len);
memset(p2, 0, i);
p2 += i;
- buf_len -= i;
nbytes -= i;
+
+ buf_len -= i;
+ if (!buf_len) {
+ sg_miter_next(&miter);
+ buf_len = miter.length;
+ p2 = miter.addr;
+ }
}
for (i = a->nlimbs - 1; i >= 0; i--) {
@@ -293,17 +300,16 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned nbytes,
p = (u8 *)&alimb;
for (x = 0; x < sizeof(alimb); x++) {
- if (!buf_len) {
- sgl = sg_next(sgl);
- if (!sgl)
- return -EINVAL;
- buf_len = sgl->length;
- p2 = sg_virt(sgl);
- }
*p2++ = *p++;
- buf_len--;
+ if (!--buf_len) {
+ sg_miter_next(&miter);
+ buf_len = miter.length;
+ p2 = miter.addr;
+ }
}
}
+
+ sg_miter_stop(&miter);
return 0;
}
EXPORT_SYMBOL_GPL(mpi_write_to_sgl);
@@ -323,19 +329,23 @@ EXPORT_SYMBOL_GPL(mpi_write_to_sgl);
*/
MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
{
- struct scatterlist *sg;
- int x, i, j, z, lzeros, ents;
+ struct sg_mapping_iter miter;
unsigned int nbits, nlimbs;
+ int x, j, z, lzeros, ents;
+ unsigned int len;
+ const u8 *buff;
mpi_limb_t a;
MPI val = NULL;
- lzeros = 0;
- ents = sg_nents(sgl);
+ ents = sg_nents_for_len(sgl, nbytes);
+ if (ents < 0)
+ return NULL;
- for_each_sg(sgl, sg, ents, i) {
- const u8 *buff = sg_virt(sg);
- int len = sg->length;
+ sg_miter_start(&miter, sgl, ents, SG_MITER_ATOMIC | SG_MITER_FROM_SG);
+ lzeros = 0;
+ len = 0;
+ while (nbytes > 0) {
while (len && !*buff) {
lzeros++;
len--;
@@ -345,12 +355,14 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
if (len && *buff)
break;
- ents--;
+ sg_miter_next(&miter);
+ buff = miter.addr;
+ len = miter.length;
+
nbytes -= lzeros;
lzeros = 0;
}
- sgl = sg;
nbytes -= lzeros;
nbits = nbytes * 8;
if (nbits > MAX_EXTERN_MPI_BITS) {
@@ -359,8 +371,7 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
}
if (nbytes > 0)
- nbits -= count_leading_zeros(*(u8 *)(sg_virt(sgl) + lzeros)) -
- (BITS_PER_LONG - 8);
+ nbits -= count_leading_zeros(*buff) - (BITS_PER_LONG - 8);
nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB);
val = mpi_alloc(nlimbs);
@@ -379,21 +390,24 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
z = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;
z %= BYTES_PER_MPI_LIMB;
- for_each_sg(sgl, sg, ents, i) {
- const u8 *buffer = sg_virt(sg) + lzeros;
- int len = sg->length - lzeros;
-
+ for (;;) {
for (x = 0; x < len; x++) {
a <<= 8;
- a |= *buffer++;
+ a |= *buff++;
if (((z + x + 1) % BYTES_PER_MPI_LIMB) == 0) {
val->d[j--] = a;
a = 0;
}
}
z += x;
- lzeros = 0;
+
+ if (!sg_miter_next(&miter))
+ break;
+
+ buff = miter.addr;
+ len = miter.length;
}
+
return val;
}
EXPORT_SYMBOL_GPL(mpi_read_raw_from_sgl);
Currently the mpi SG helpers use sg_virt which is completely broken. It happens to work with normal kernel memory but will fail with anything that is not linearly mapped. This patch fixes this by using the SG iterator helpers. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> --- lib/mpi/mpicoder.c | 86 ++++++++++++++++++++++++++++++----------------------- 1 file changed, 50 insertions(+), 36 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html