From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
get rid of set_fs() in csum_partial_copy_nocheck(), while we are at it -
just take the part of csum_and_copy_from_user() sans the access_ok() check
into a helper function and have csum_partial_copy_nocheck() call that.
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
arch/alpha/lib/csum_partial_copy.c | 157 ++++++++++++++++---------------------
1 file changed, 69 insertions(+), 88 deletions(-)
diff --git a/arch/alpha/lib/csum_partial_copy.c b/arch/alpha/lib/csum_partial_copy.c
index 3c0e89c39ddb..dc68efbe9367 100644
--- a/arch/alpha/lib/csum_partial_copy.c
+++ b/arch/alpha/lib/csum_partial_copy.c
@@ -39,12 +39,11 @@ __asm__ __volatile__("insql %1,%2,%0":"=r" (z):"r" (x),"r" (y))
#define insqh(x,y,z) \
__asm__ __volatile__("insqh %1,%2,%0":"=r" (z):"r" (x),"r" (y))
-
-#define __get_user_u(x,ptr) \
+#define __get_word(insn,x,ptr) \
({ \
long __guu_err; \
__asm__ __volatile__( \
- "1: ldq_u %0,%2\n" \
+ "1: "#insn" %0,%2\n" \
"2:\n" \
EXC(1b,2b,%0,%1) \
: "=r"(x), "=r"(__guu_err) \
@@ -52,19 +51,6 @@ __asm__ __volatile__("insqh %1,%2,%0":"=r" (z):"r" (x),"r" (y))
__guu_err; \
})
-#define __put_user_u(x,ptr) \
-({ \
- long __puu_err; \
- __asm__ __volatile__( \
- "1: stq_u %2,%1\n" \
- "2:\n" \
- EXC(1b,2b,$31,%0) \
- : "=r"(__puu_err) \
- : "m"(__m(addr)), "rJ"(x), "0"(0)); \
- __puu_err; \
-})
-
-
static inline unsigned short from64to16(unsigned long x)
{
/* Using extract instructions is a bit more efficient
@@ -95,15 +81,15 @@ static inline unsigned short from64to16(unsigned long x)
*/
static inline unsigned long
csum_partial_cfu_aligned(const unsigned long __user *src, unsigned long *dst,
- long len, unsigned long checksum,
- int *errp)
+ long len)
{
+ unsigned long checksum = ~0U;
unsigned long carry = 0;
- int err = 0;
while (len >= 0) {
unsigned long word;
- err |= __get_user(word, src);
+ if (__get_word(ldq, word, src))
+ return 0;
checksum += carry;
src++;
checksum += word;
@@ -116,7 +102,8 @@ csum_partial_cfu_aligned(const unsigned long __user *src, unsigned long *dst,
checksum += carry;
if (len) {
unsigned long word, tmp;
- err |= __get_user(word, src);
+ if (__get_word(ldq, word, src))
+ return 0;
tmp = *dst;
mskql(word, len, word);
checksum += word;
@@ -125,7 +112,6 @@ csum_partial_cfu_aligned(const unsigned long __user *src, unsigned long *dst,
*dst = word | tmp;
checksum += carry;
}
- if (err && errp) *errp = err;
return checksum;
}
@@ -137,20 +123,21 @@ static inline unsigned long
csum_partial_cfu_dest_aligned(const unsigned long __user *src,
unsigned long *dst,
unsigned long soff,
- long len, unsigned long checksum,
- int *errp)
+ long len)
{
unsigned long first;
unsigned long word, carry;
unsigned long lastsrc = 7+len+(unsigned long)src;
- int err = 0;
+ unsigned long checksum = ~0U;
- err |= __get_user_u(first,src);
+ if (__get_word(ldq_u, first,src))
+ return 0;
carry = 0;
while (len >= 0) {
unsigned long second;
- err |= __get_user_u(second, src+1);
+ if (__get_word(ldq_u, second, src+1))
+ return 0;
extql(first, soff, word);
len -= 8;
src++;
@@ -168,7 +155,8 @@ csum_partial_cfu_dest_aligned(const unsigned long __user *src,
if (len) {
unsigned long tmp;
unsigned long second;
- err |= __get_user_u(second, lastsrc);
+ if (__get_word(ldq_u, second, lastsrc))
+ return 0;
tmp = *dst;
extql(first, soff, word);
extqh(second, soff, first);
@@ -180,7 +168,6 @@ csum_partial_cfu_dest_aligned(const unsigned long __user *src,
*dst = word | tmp;
checksum += carry;
}
- if (err && errp) *errp = err;
return checksum;
}
@@ -191,18 +178,18 @@ static inline unsigned long
csum_partial_cfu_src_aligned(const unsigned long __user *src,
unsigned long *dst,
unsigned long doff,
- long len, unsigned long checksum,
- unsigned long partial_dest,
- int *errp)
+ long len,
+ unsigned long partial_dest)
{
unsigned long carry = 0;
unsigned long word;
unsigned long second_dest;
- int err = 0;
+ unsigned long checksum = ~0U;
mskql(partial_dest, doff, partial_dest);
while (len >= 0) {
- err |= __get_user(word, src);
+ if (__get_word(ldq, word, src))
+ return 0;
len -= 8;
insql(word, doff, second_dest);
checksum += carry;
@@ -216,7 +203,8 @@ csum_partial_cfu_src_aligned(const unsigned long __user *src,
len += 8;
if (len) {
checksum += carry;
- err |= __get_user(word, src);
+ if (__get_word(ldq, word, src))
+ return 0;
mskql(word, len, word);
len -= 8;
checksum += word;
@@ -237,7 +225,6 @@ csum_partial_cfu_src_aligned(const unsigned long __user *src,
stq_u(partial_dest | second_dest, dst);
out:
checksum += carry;
- if (err && errp) *errp = err;
return checksum;
}
@@ -249,23 +236,23 @@ static inline unsigned long
csum_partial_cfu_unaligned(const unsigned long __user * src,
unsigned long * dst,
unsigned long soff, unsigned long doff,
- long len, unsigned long checksum,
- unsigned long partial_dest,
- int *errp)
+ long len, unsigned long partial_dest)
{
unsigned long carry = 0;
unsigned long first;
unsigned long lastsrc;
- int err = 0;
+ unsigned long checksum = ~0U;
- err |= __get_user_u(first, src);
+ if (__get_word(ldq_u, first, src))
+ return 0;
lastsrc = 7+len+(unsigned long)src;
mskql(partial_dest, doff, partial_dest);
while (len >= 0) {
unsigned long second, word;
unsigned long second_dest;
- err |= __get_user_u(second, src+1);
+ if (__get_word(ldq_u, second, src+1))
+ return 0;
extql(first, soff, word);
checksum += carry;
len -= 8;
@@ -286,7 +273,8 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
unsigned long second, word;
unsigned long second_dest;
- err |= __get_user_u(second, lastsrc);
+ if (__get_word(ldq_u, second, lastsrc))
+ return 0;
extql(first, soff, word);
extqh(second, soff, first);
word |= first;
@@ -307,7 +295,8 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
unsigned long second, word;
unsigned long second_dest;
- err |= __get_user_u(second, lastsrc);
+ if (__get_word(ldq_u, second, lastsrc))
+ return 0;
extql(first, soff, word);
extqh(second, soff, first);
word |= first;
@@ -320,63 +309,55 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
stq_u(partial_dest | word | second_dest, dst);
checksum += carry;
}
- if (err && errp) *errp = err;
return checksum;
}
-__wsum
-csum_and_copy_from_user(const void __user *src, void *dst, int len)
+static __wsum __csum_and_copy(const void __user *src, void *dst, int len)
{
- unsigned long checksum = ~0U;
unsigned long soff = 7 & (unsigned long) src;
unsigned long doff = 7 & (unsigned long) dst;
- int err = 0;
-
- if (len) {
- if (!access_ok(src, len))
- return 0;
- if (!doff) {
- if (!soff)
- checksum = csum_partial_cfu_aligned(
- (const unsigned long __user *) src,
- (unsigned long *) dst,
- len-8, checksum, &err);
- else
- checksum = csum_partial_cfu_dest_aligned(
- (const unsigned long __user *) src,
- (unsigned long *) dst,
- soff, len-8, checksum, &err);
- } else {
- unsigned long partial_dest;
- ldq_u(partial_dest, dst);
- if (!soff)
- checksum = csum_partial_cfu_src_aligned(
- (const unsigned long __user *) src,
- (unsigned long *) dst,
- doff, len-8, checksum,
- partial_dest, &err);
- else
- checksum = csum_partial_cfu_unaligned(
- (const unsigned long __user *) src,
- (unsigned long *) dst,
- soff, doff, len-8, checksum,
- partial_dest, &err);
- }
- checksum = err ? 0 : from64to16 (checksum);
+ unsigned long checksum;
+
+ if (!doff) {
+ if (!soff)
+ checksum = csum_partial_cfu_aligned(
+ (const unsigned long __user *) src,
+ (unsigned long *) dst, len-8);
+ else
+ checksum = csum_partial_cfu_dest_aligned(
+ (const unsigned long __user *) src,
+ (unsigned long *) dst,
+ soff, len-8);
+ } else {
+ unsigned long partial_dest;
+ ldq_u(partial_dest, dst);
+ if (!soff)
+ checksum = csum_partial_cfu_src_aligned(
+ (const unsigned long __user *) src,
+ (unsigned long *) dst,
+ doff, len-8, partial_dest);
+ else
+ checksum = csum_partial_cfu_unaligned(
+ (const unsigned long __user *) src,
+ (unsigned long *) dst,
+ soff, doff, len-8, partial_dest);
}
- return (__force __wsum)checksum;
+ return (__force __wsum)from64to16 (checksum);
+}
+
+__wsum
+csum_and_copy_from_user(const void __user *src, void *dst, int len)
+{
+ if (!access_ok(src, len))
+ return 0;
+ return __csum_and_copy(src, dst, len);
}
EXPORT_SYMBOL(csum_and_copy_from_user);
__wsum
csum_partial_copy_nocheck(const void *src, void *dst, int len)
{
- __wsum checksum;
- mm_segment_t oldfs = get_fs();
- set_fs(KERNEL_DS);
- checksum = csum_and_copy_from_user((__force const void __user *)src,
+ return __csum_and_copy((__force const void __user *)src,
dst, len);
- set_fs(oldfs);
- return checksum;
}
EXPORT_SYMBOL(csum_partial_copy_nocheck);
--
2.11.0
