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authorAl Viro <viro@zeniv.linux.org.uk>2020-07-13 05:53:10 +0200
committerAl Viro <viro@zeniv.linux.org.uk>2020-08-20 21:45:18 +0200
commite8b95089990ceac4e5197db3c03737bf569f5081 (patch)
treea4daa20395fa30a564d2fe7beff53ed8a28fa2d2 /arch/x86/lib
parentsh: propage the calling conventions change down to csum_partial_copy_generic() (diff)
downloadlinux-e8b95089990ceac4e5197db3c03737bf569f5081.tar.xz
linux-e8b95089990ceac4e5197db3c03737bf569f5081.zip
i386: propagate the calling conventions change down to csum_partial_copy_generic()
... and don't bother zeroing destination on error Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/x86/lib')
-rw-r--r--arch/x86/lib/checksum_32.S117
1 files changed, 41 insertions, 76 deletions
diff --git a/arch/x86/lib/checksum_32.S b/arch/x86/lib/checksum_32.S
index d1d768912368..4304320e51f4 100644
--- a/arch/x86/lib/checksum_32.S
+++ b/arch/x86/lib/checksum_32.S
@@ -253,28 +253,17 @@ EXPORT_SYMBOL(csum_partial)
/*
unsigned int csum_partial_copy_generic (const char *src, char *dst,
- int len, int sum, int *src_err_ptr, int *dst_err_ptr)
+ int len)
*/
/*
* Copy from ds while checksumming, otherwise like csum_partial
- *
- * The macros SRC and DST specify the type of access for the instruction.
- * thus we can call a custom exception handler for all access types.
- *
- * FIXME: could someone double-check whether I haven't mixed up some SRC and
- * DST definitions? It's damn hard to trigger all cases. I hope I got
- * them all but there's no guarantee.
*/
-#define SRC(y...) \
+#define EXC(y...) \
9999: y; \
_ASM_EXTABLE_UA(9999b, 6001f)
-#define DST(y...) \
- 9999: y; \
- _ASM_EXTABLE_UA(9999b, 6002f)
-
#ifndef CONFIG_X86_USE_PPRO_CHECKSUM
#define ARGBASE 16
@@ -285,20 +274,20 @@ SYM_FUNC_START(csum_partial_copy_generic)
pushl %edi
pushl %esi
pushl %ebx
- movl ARGBASE+16(%esp),%eax # sum
movl ARGBASE+12(%esp),%ecx # len
movl ARGBASE+4(%esp),%esi # src
movl ARGBASE+8(%esp),%edi # dst
+ movl $-1, %eax # sum
testl $2, %edi # Check alignment.
jz 2f # Jump if alignment is ok.
subl $2, %ecx # Alignment uses up two bytes.
jae 1f # Jump if we had at least two bytes.
addl $2, %ecx # ecx was < 2. Deal with it.
jmp 4f
-SRC(1: movw (%esi), %bx )
+EXC(1: movw (%esi), %bx )
addl $2, %esi
-DST( movw %bx, (%edi) )
+EXC( movw %bx, (%edi) )
addl $2, %edi
addw %bx, %ax
adcl $0, %eax
@@ -306,34 +295,34 @@ DST( movw %bx, (%edi) )
movl %ecx, FP(%esp)
shrl $5, %ecx
jz 2f
- testl %esi, %esi
-SRC(1: movl (%esi), %ebx )
-SRC( movl 4(%esi), %edx )
+ testl %esi, %esi # what's wrong with clc?
+EXC(1: movl (%esi), %ebx )
+EXC( movl 4(%esi), %edx )
adcl %ebx, %eax
-DST( movl %ebx, (%edi) )
+EXC( movl %ebx, (%edi) )
adcl %edx, %eax
-DST( movl %edx, 4(%edi) )
+EXC( movl %edx, 4(%edi) )
-SRC( movl 8(%esi), %ebx )
-SRC( movl 12(%esi), %edx )
+EXC( movl 8(%esi), %ebx )
+EXC( movl 12(%esi), %edx )
adcl %ebx, %eax
-DST( movl %ebx, 8(%edi) )
+EXC( movl %ebx, 8(%edi) )
adcl %edx, %eax
-DST( movl %edx, 12(%edi) )
+EXC( movl %edx, 12(%edi) )
-SRC( movl 16(%esi), %ebx )
-SRC( movl 20(%esi), %edx )
+EXC( movl 16(%esi), %ebx )
+EXC( movl 20(%esi), %edx )
adcl %ebx, %eax
-DST( movl %ebx, 16(%edi) )
+EXC( movl %ebx, 16(%edi) )
adcl %edx, %eax
-DST( movl %edx, 20(%edi) )
+EXC( movl %edx, 20(%edi) )
-SRC( movl 24(%esi), %ebx )
-SRC( movl 28(%esi), %edx )
+EXC( movl 24(%esi), %ebx )
+EXC( movl 28(%esi), %edx )
adcl %ebx, %eax
-DST( movl %ebx, 24(%edi) )
+EXC( movl %ebx, 24(%edi) )
adcl %edx, %eax
-DST( movl %edx, 28(%edi) )
+EXC( movl %edx, 28(%edi) )
lea 32(%esi), %esi
lea 32(%edi), %edi
@@ -345,9 +334,9 @@ DST( movl %edx, 28(%edi) )
andl $0x1c, %edx
je 4f
shrl $2, %edx # This clears CF
-SRC(3: movl (%esi), %ebx )
+EXC(3: movl (%esi), %ebx )
adcl %ebx, %eax
-DST( movl %ebx, (%edi) )
+EXC( movl %ebx, (%edi) )
lea 4(%esi), %esi
lea 4(%edi), %edi
dec %edx
@@ -357,39 +346,24 @@ DST( movl %ebx, (%edi) )
jz 7f
cmpl $2, %ecx
jb 5f
-SRC( movw (%esi), %cx )
+EXC( movw (%esi), %cx )
leal 2(%esi), %esi
-DST( movw %cx, (%edi) )
+EXC( movw %cx, (%edi) )
leal 2(%edi), %edi
je 6f
shll $16,%ecx
-SRC(5: movb (%esi), %cl )
-DST( movb %cl, (%edi) )
+EXC(5: movb (%esi), %cl )
+EXC( movb %cl, (%edi) )
6: addl %ecx, %eax
adcl $0, %eax
7:
-5000:
# Exception handler:
.section .fixup, "ax"
6001:
- movl ARGBASE+20(%esp), %ebx # src_err_ptr
- movl $-EFAULT, (%ebx)
-
- # zero the complete destination - computing the rest
- # is too much work
- movl ARGBASE+8(%esp), %edi # dst
- movl ARGBASE+12(%esp), %ecx # len
- xorl %eax,%eax
- rep ; stosb
-
- jmp 5000b
-
-6002:
- movl ARGBASE+24(%esp), %ebx # dst_err_ptr
- movl $-EFAULT,(%ebx)
- jmp 5000b
+ xorl %eax, %eax
+ jmp 7b
.previous
@@ -405,14 +379,14 @@ SYM_FUNC_END(csum_partial_copy_generic)
/* Version for PentiumII/PPro */
#define ROUND1(x) \
- SRC(movl x(%esi), %ebx ) ; \
+ EXC(movl x(%esi), %ebx ) ; \
addl %ebx, %eax ; \
- DST(movl %ebx, x(%edi) ) ;
+ EXC(movl %ebx, x(%edi) ) ;
#define ROUND(x) \
- SRC(movl x(%esi), %ebx ) ; \
+ EXC(movl x(%esi), %ebx ) ; \
adcl %ebx, %eax ; \
- DST(movl %ebx, x(%edi) ) ;
+ EXC(movl %ebx, x(%edi) ) ;
#define ARGBASE 12
@@ -423,7 +397,7 @@ SYM_FUNC_START(csum_partial_copy_generic)
movl ARGBASE+4(%esp),%esi #src
movl ARGBASE+8(%esp),%edi #dst
movl ARGBASE+12(%esp),%ecx #len
- movl ARGBASE+16(%esp),%eax #sum
+ movl $-1, %eax #sum
# movl %ecx, %edx
movl %ecx, %ebx
movl %esi, %edx
@@ -439,7 +413,7 @@ SYM_FUNC_START(csum_partial_copy_generic)
JMP_NOSPEC ebx
1: addl $64,%esi
addl $64,%edi
- SRC(movb -32(%edx),%bl) ; SRC(movb (%edx),%bl)
+ EXC(movb -32(%edx),%bl) ; EXC(movb (%edx),%bl)
ROUND1(-64) ROUND(-60) ROUND(-56) ROUND(-52)
ROUND (-48) ROUND(-44) ROUND(-40) ROUND(-36)
ROUND (-32) ROUND(-28) ROUND(-24) ROUND(-20)
@@ -453,29 +427,20 @@ SYM_FUNC_START(csum_partial_copy_generic)
jz 7f
cmpl $2, %edx
jb 5f
-SRC( movw (%esi), %dx )
+EXC( movw (%esi), %dx )
leal 2(%esi), %esi
-DST( movw %dx, (%edi) )
+EXC( movw %dx, (%edi) )
leal 2(%edi), %edi
je 6f
shll $16,%edx
5:
-SRC( movb (%esi), %dl )
-DST( movb %dl, (%edi) )
+EXC( movb (%esi), %dl )
+EXC( movb %dl, (%edi) )
6: addl %edx, %eax
adcl $0, %eax
7:
.section .fixup, "ax"
-6001: movl ARGBASE+20(%esp), %ebx # src_err_ptr
- movl $-EFAULT, (%ebx)
- # zero the complete destination (computing the rest is too much work)
- movl ARGBASE+8(%esp),%edi # dst
- movl ARGBASE+12(%esp),%ecx # len
- xorl %eax,%eax
- rep; stosb
- jmp 7b
-6002: movl ARGBASE+24(%esp), %ebx # dst_err_ptr
- movl $-EFAULT, (%ebx)
+6001: xorl %eax, %eax
jmp 7b
.previous