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authorHerbert Xu <herbert@gondor.apana.org.au>2016-06-29 19:32:22 +0800
committerHerbert Xu <herbert@gondor.apana.org.au>2016-07-01 23:45:18 +0800
commit127827b9c295db35fa7e49d00ac5d14faeda9461 (patch)
tree67e4d277b950edc54b1f611ba810c35ad958e253 /lib
parent9b45b7bba3d22de52e09df63c50f390a193a3f53 (diff)
downloadlinux-stericsson-127827b9c295db35fa7e49d00ac5d14faeda9461.tar.gz
lib/mpi: Do not do sg_virt
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>
Diffstat (limited to 'lib')
-rw-r--r--lib/mpi/mpicoder.c86
1 files changed, 50 insertions, 36 deletions
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
index 7150e5c23604..c6272ae2015e 100644
--- a/lib/mpi/mpicoder.c
+++ b/lib/mpi/mpicoder.c
@@ -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);