From: Al Viro <v...@zeniv.linux.org.uk>
... and get rid of the "clean the destination on error" crap.
Simplifies the fault handlers and the function itself...
Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
---
arch/arm/include/asm/checksum.h | 7 ++-----
arch/arm/lib/csumpartialcopy.S | 1 -
arch/arm/lib/csumpartialcopygeneric.S | 1 +
arch/arm/lib/csumpartialcopyuser.S | 26 ++++++--------------------
4 files changed, 9 insertions(+), 26 deletions(-)
diff --git a/arch/arm/include/asm/checksum.h b/arch/arm/include/asm/checksum.h
index 737db6c3c482..d434986e81b2 100644
--- a/arch/arm/include/asm/checksum.h
+++ b/arch/arm/include/asm/checksum.h
@@ -38,19 +38,16 @@ __wsum
csum_partial_copy_nocheck(const void *src, void *dst, int len);
__wsum
-csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum
sum, int *err_ptr);
+csum_partial_copy_from_user(const void __user *src, void *dst, int len);
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
static inline
__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len)
{
- int err = 0;
-
if (!access_ok(src, len))
return 0;
- sum = csum_partial_copy_from_user(src, dst, len, ~0U, &err);
- return err ? 0 : sum;
+ return csum_partial_copy_from_user(src, dst, len);
}
/*
diff --git a/arch/arm/lib/csumpartialcopy.S b/arch/arm/lib/csumpartialcopy.S
index aab914fbc86b..1ca6aadd649c 100644
--- a/arch/arm/lib/csumpartialcopy.S
+++ b/arch/arm/lib/csumpartialcopy.S
@@ -16,7 +16,6 @@
.macro save_regs
stmfd sp!, {r1, r4 - r8, lr}
- mov r3, #0
.endm
.macro load_regs
diff --git a/arch/arm/lib/csumpartialcopygeneric.S
b/arch/arm/lib/csumpartialcopygeneric.S
index 0b706a39a677..0fd5c10e90a7 100644
--- a/arch/arm/lib/csumpartialcopygeneric.S
+++ b/arch/arm/lib/csumpartialcopygeneric.S
@@ -86,6 +86,7 @@ sum .req r3
FN_ENTRY
save_regs
+ mov sum, #-1
cmp len, #8 @ Ensure that we have at least
blo .Lless8 @ 8 bytes to copy.
diff --git a/arch/arm/lib/csumpartialcopyuser.S
b/arch/arm/lib/csumpartialcopyuser.S
index 6bd3a93eaa3c..6928781e6bee 100644
--- a/arch/arm/lib/csumpartialcopyuser.S
+++ b/arch/arm/lib/csumpartialcopyuser.S
@@ -62,9 +62,9 @@
/*
* unsigned int
- * csum_partial_copy_from_user(const char *src, char *dst, int len, int sum,
int *err_ptr)
- * r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
- * Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
+ * csum_partial_copy_from_user(const char *src, char *dst, int len)
+ * r0 = src, r1 = dst, r2 = len
+ * Returns : r0 = checksum or 0
*/
#define FN_ENTRY ENTRY(csum_partial_copy_from_user)
@@ -73,25 +73,11 @@
#include "csumpartialcopygeneric.S"
/*
- * FIXME: minor buglet here
- * We don't return the checksum for the data present in the buffer. To do
- * so properly, we would have to add in whatever registers were loaded before
- * the fault, which, with the current asm above is not predictable.
+ * We report fault by returning 0 csum - impossible in normal case, since
+ * we start with 0xffffffff for initial sum.
*/
.pushsection .text.fixup,"ax"
.align 4
-9001: mov r4, #-EFAULT
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
- ldr r5, [sp, #9*4] @ *err_ptr
-#else
- ldr r5, [sp, #8*4] @ *err_ptr
-#endif
- str r4, [r5]
- ldmia sp, {r1, r2} @ retrieve dst, len
- add r2, r2, r1
- mov r0, #0 @ zero the buffer
-9002: teq r2, r1
- strbne r0, [r1], #1
- bne 9002b
+9001: mov r0, #0
load_regs
.popsection
--
2.11.0
