arm: propagate the calling convention changes down to csum_partial_copy_from_user()

... and get rid of the "clean the destination on error" crap.
Simplifies the fault handlers and the function itself...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/arch/arm/include/asm/checksum.h b/arch/arm/include/asm/checksum.h
index 1601c13..f0f54ae 100644 (file)
--- a/arch/arm/include/asm/checksum.h
+++ b/arch/arm/include/asm/checksum.h
@@ -38,20 +38,17 @@ __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
 #define _HAVE_ARCH_CSUM_AND_COPY
 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 aab914f..1ca6aad 100644 (file)
--- 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 0b706a3..0fd5c10 100644 (file)
--- 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 6bd3a93..6928781 100644 (file)
--- 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