From e8b95089990ceac4e5197db3c03737bf569f5081 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 12 Jul 2020 23:53:10 -0400 Subject: [PATCH] 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 --- arch/x86/include/asm/checksum_32.h | 18 ++--- arch/x86/lib/checksum_32.S | 117 ++++++++++------------------- 2 files changed, 47 insertions(+), 88 deletions(-) diff --git a/arch/x86/include/asm/checksum_32.h b/arch/x86/include/asm/checksum_32.h index 5948cde9e4ad..17da95387997 100644 --- a/arch/x86/include/asm/checksum_32.h +++ b/arch/x86/include/asm/checksum_32.h @@ -27,9 +27,7 @@ asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum); * better 64-bit) boundary */ -asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, - int len, __wsum sum, - int *src_err_ptr, int *dst_err_ptr); +asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, int len); /* * Note: when you get a NULL pointer exception here this means someone @@ -40,23 +38,21 @@ asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, */ static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len) { - return csum_partial_copy_generic(src, dst, len, 0, NULL, NULL); + return csum_partial_copy_generic(src, dst, len); } static inline __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len) { __wsum ret; - int err = 0; might_sleep(); if (!user_access_begin(src, len)) return 0; - ret = csum_partial_copy_generic((__force void *)src, dst, - len, ~0U, &err, NULL); + ret = csum_partial_copy_generic((__force void *)src, dst, len); user_access_end(); - return err ? 0 : ret; + return ret; } /* @@ -177,16 +173,14 @@ static inline __wsum csum_and_copy_to_user(const void *src, int len) { __wsum ret; - int err = 0; might_sleep(); if (!user_access_begin(dst, len)) return 0; - ret = csum_partial_copy_generic(src, (__force void *)dst, - len, ~0U, NULL, &err); + ret = csum_partial_copy_generic(src, (__force void *)dst, len); user_access_end(); - return err ? 0 : ret; + return ret; } #endif /* _ASM_X86_CHECKSUM_32_H */ 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