[PATCH 3.14 020/122] crypto: caam - remove duplicated sg copy functions

From: Greg Kroah-Hartman
Date: Wed Nov 19 2014 - 17:08:14 EST

3.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Cristian Stoica <cristian.stoica@xxxxxxxxxxxxx>

commit 307fd543f3d23f8f56850eca1b27b1be2fe71017 upstream.

Replace equivalent (and partially incorrect) scatter-gather functions
with ones from crypto-API.

The replacement is motivated by page-faults in sg_copy_part triggered
by successive calls to crypto_hash_update. The following fault appears
after calling crypto_ahash_update twice, first with 13 and then
with 285 bytes:

Unable to handle kernel paging request for data at address 0x00000008
Faulting instruction address: 0xf9bf9a8c
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=8 CoreNet Generic
Modules linked in: tcrypt(+) caamhash caam_jr caam tls
CPU: 6 PID: 1497 Comm: cryptomgr_test Not tainted
3.12.19-rt30-QorIQ-SDK-V1.6+g9fda9f2 #75
task: e9308530 ti: e700e000 task.ti: e700e000
NIP: f9bf9a8c LR: f9bfcf28 CTR: c0019ea0
REGS: e700fb80 TRAP: 0300 Not tainted
(3.12.19-rt30-QorIQ-SDK-V1.6+g9fda9f2)
MSR: 00029002 <CE,EE,ME> CR: 44f92024 XER: 20000000
DEAR: 00000008, ESR: 00000000

GPR00: f9bfcf28 e700fc30 e9308530 e70b1e55 00000000 ffffffdd e70b1e54 0bebf888
GPR08: 902c7ef5 c0e771e2 00000002 00000888 c0019ea0 00000000 00000000 c07a4154
GPR16: c08d0000 e91a8f9c 00000001 e98fb400 00000100 e9c83028 e70b1e08 e70b1d48
GPR24: e992ce10 e70b1dc8 f9bfe4f4 e70b1e55 ffffffdd e70b1ce0 00000000 00000000
NIP [f9bf9a8c] sg_copy+0x1c/0x100 [caamhash]
LR [f9bfcf28] ahash_update_no_ctx+0x628/0x660 [caamhash]
Call Trace:
[e700fc30] [f9bf9c50] sg_copy_part+0xe0/0x160 [caamhash] (unreliable)
[e700fc50] [f9bfcf28] ahash_update_no_ctx+0x628/0x660 [caamhash]
[e700fcb0] [f954e19c] crypto_tls_genicv+0x13c/0x300 [tls]
[e700fd10] [f954e65c] crypto_tls_encrypt+0x5c/0x260 [tls]
[e700fd40] [c02250ec] __test_aead.constprop.9+0x2bc/0xb70
[e700fe40] [c02259f0] alg_test_aead+0x50/0xc0
[e700fe60] [c02241e4] alg_test+0x114/0x2e0
[e700fee0] [c022276c] cryptomgr_test+0x4c/0x60
[e700fef0] [c004f658] kthread+0x98/0xa0
[e700ff40] [c000fd04] ret_from_kernel_thread+0x5c/0x64

Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Cristian Stoica <cristian.stoica@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/crypto/caam/caamhash.c | 22 ++++++++++-----
drivers/crypto/caam/sg_sw_sec4.h | 54 ---------------------------------------
2 files changed, 14 insertions(+), 62 deletions(-)

--- a/drivers/crypto/caam/caamhash.c
+++ b/drivers/crypto/caam/caamhash.c
@@ -835,8 +835,9 @@ static int ahash_update_ctx(struct ahash
edesc->sec4_sg + sec4_sg_src_index,
chained);
if (*next_buflen) {
- sg_copy_part(next_buf, req->src, to_hash -
- *buflen, req->nbytes);
+ scatterwalk_map_and_copy(next_buf, req->src,
+ to_hash - *buflen,
+ *next_buflen, 0);
state->current_buf = !state->current_buf;
}
} else {
@@ -869,7 +870,8 @@ static int ahash_update_ctx(struct ahash
kfree(edesc);
}
} else if (*next_buflen) {
- sg_copy(buf + *buflen, req->src, req->nbytes);
+ scatterwalk_map_and_copy(buf + *buflen, req->src, 0,
+ req->nbytes, 0);
*buflen = *next_buflen;
*next_buflen = last_buflen;
}
@@ -1216,8 +1218,9 @@ static int ahash_update_no_ctx(struct ah
src_map_to_sec4_sg(jrdev, req->src, src_nents,
edesc->sec4_sg + 1, chained);
if (*next_buflen) {
- sg_copy_part(next_buf, req->src, to_hash - *buflen,
- req->nbytes);
+ scatterwalk_map_and_copy(next_buf, req->src,
+ to_hash - *buflen,
+ *next_buflen, 0);
state->current_buf = !state->current_buf;
}

@@ -1248,7 +1251,8 @@ static int ahash_update_no_ctx(struct ah
kfree(edesc);
}
} else if (*next_buflen) {
- sg_copy(buf + *buflen, req->src, req->nbytes);
+ scatterwalk_map_and_copy(buf + *buflen, req->src, 0,
+ req->nbytes, 0);
*buflen = *next_buflen;
*next_buflen = 0;
}
@@ -1405,7 +1409,8 @@ static int ahash_update_first(struct aha
}

if (*next_buflen)
- sg_copy_part(next_buf, req->src, to_hash, req->nbytes);
+ scatterwalk_map_and_copy(next_buf, req->src, to_hash,
+ *next_buflen, 0);

sh_len = desc_len(sh_desc);
desc = edesc->hw_desc;
@@ -1438,7 +1443,8 @@ static int ahash_update_first(struct aha
state->update = ahash_update_no_ctx;
state->finup = ahash_finup_no_ctx;
state->final = ahash_final_no_ctx;
- sg_copy(next_buf, req->src, req->nbytes);
+ scatterwalk_map_and_copy(next_buf, req->src, 0,
+ req->nbytes, 0);
}
#ifdef DEBUG
print_hex_dump(KERN_ERR, "next buf@"__stringify(__LINE__)": ",
--- a/drivers/crypto/caam/sg_sw_sec4.h
+++ b/drivers/crypto/caam/sg_sw_sec4.h
@@ -116,57 +116,3 @@ static int dma_unmap_sg_chained(struct d
}
return nents;
}
-
-/* Map SG page in kernel virtual address space and copy */
-static inline void sg_map_copy(u8 *dest, struct scatterlist *sg,
- int len, int offset)
-{
- u8 *mapped_addr;
-
- /*
- * Page here can be user-space pinned using get_user_pages
- * Same must be kmapped before use and kunmapped subsequently
- */
- mapped_addr = kmap_atomic(sg_page(sg));
- memcpy(dest, mapped_addr + offset, len);
- kunmap_atomic(mapped_addr);
-}
-
-/* Copy from len bytes of sg to dest, starting from beginning */
-static inline void sg_copy(u8 *dest, struct scatterlist *sg, unsigned int len)
-{
- struct scatterlist *current_sg = sg;
- int cpy_index = 0, next_cpy_index = current_sg->length;
-
- while (next_cpy_index < len) {
- sg_map_copy(dest + cpy_index, current_sg, current_sg->length,
- current_sg->offset);
- current_sg = scatterwalk_sg_next(current_sg);
- cpy_index = next_cpy_index;
- next_cpy_index += current_sg->length;
- }
- if (cpy_index < len)
- sg_map_copy(dest + cpy_index, current_sg, len-cpy_index,
- current_sg->offset);
-}
-
-/* Copy sg data, from to_skip to end, to dest */
-static inline void sg_copy_part(u8 *dest, struct scatterlist *sg,
- int to_skip, unsigned int end)
-{
- struct scatterlist *current_sg = sg;
- int sg_index, cpy_index, offset;
-
- sg_index = current_sg->length;
- while (sg_index <= to_skip) {
- current_sg = scatterwalk_sg_next(current_sg);
- sg_index += current_sg->length;
- }
- cpy_index = sg_index - to_skip;
- offset = current_sg->offset + current_sg->length - cpy_index;
- sg_map_copy(dest, current_sg, cpy_index, offset);
- if (end - sg_index) {
- current_sg = scatterwalk_sg_next(current_sg);
- sg_copy(dest + cpy_index, current_sg, end - sg_index);
- }
-}


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