diff options
Diffstat (limited to 'arch/x86/lib')
-rw-r--r-- | arch/x86/lib/Makefile | 5 | ||||
-rw-r--r-- | arch/x86/lib/copy_user_64.S | 429 | ||||
-rw-r--r-- | arch/x86/lib/copy_user_nocache_64.S | 283 | ||||
-rw-r--r-- | arch/x86/lib/delay.c (renamed from arch/x86/lib/delay_32.c) | 38 | ||||
-rw-r--r-- | arch/x86/lib/delay_64.c | 85 | ||||
-rw-r--r-- | arch/x86/lib/getuser.S (renamed from arch/x86/lib/getuser_64.S) | 87 | ||||
-rw-r--r-- | arch/x86/lib/getuser_32.S | 78 | ||||
-rw-r--r-- | arch/x86/lib/putuser.S (renamed from arch/x86/lib/putuser_32.S) | 73 | ||||
-rw-r--r-- | arch/x86/lib/putuser_64.S | 106 | ||||
-rw-r--r-- | arch/x86/lib/thunk_32.S | 47 | ||||
-rw-r--r-- | arch/x86/lib/thunk_64.S | 19 | ||||
-rw-r--r-- | arch/x86/lib/usercopy_64.c | 23 |
12 files changed, 465 insertions, 808 deletions
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 76f60f52a88..aa3fa411942 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -4,8 +4,9 @@ obj-$(CONFIG_SMP) := msr-on-cpu.o -lib-y := delay_$(BITS).o -lib-y += usercopy_$(BITS).o getuser_$(BITS).o putuser_$(BITS).o +lib-y := delay.o +lib-y += thunk_$(BITS).o +lib-y += usercopy_$(BITS).o getuser.o putuser.o lib-y += memcpy_$(BITS).o ifeq ($(CONFIG_X86_32),y) diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index ee1c3f63515..dfdf428975c 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -1,8 +1,10 @@ -/* Copyright 2002 Andi Kleen, SuSE Labs. +/* + * Copyright 2008 Vitaly Mayatskikh <vmayatsk@redhat.com> + * Copyright 2002 Andi Kleen, SuSE Labs. * Subject to the GNU Public License v2. - * - * Functions to copy from and to user space. - */ + * + * Functions to copy from and to user space. + */ #include <linux/linkage.h> #include <asm/dwarf2.h> @@ -20,60 +22,88 @@ .long \orig-1f /* by default jump to orig */ 1: .section .altinstr_replacement,"ax" -2: .byte 0xe9 /* near jump with 32bit immediate */ +2: .byte 0xe9 /* near jump with 32bit immediate */ .long \alt-1b /* offset */ /* or alternatively to alt */ .previous .section .altinstructions,"a" .align 8 .quad 0b .quad 2b - .byte \feature /* when feature is set */ + .byte \feature /* when feature is set */ .byte 5 .byte 5 .previous .endm -/* Standard copy_to_user with segment limit checking */ + .macro ALIGN_DESTINATION +#ifdef FIX_ALIGNMENT + /* check for bad alignment of destination */ + movl %edi,%ecx + andl $7,%ecx + jz 102f /* already aligned */ + subl $8,%ecx + negl %ecx + subl %ecx,%edx +100: movb (%rsi),%al +101: movb %al,(%rdi) + incq %rsi + incq %rdi + decl %ecx + jnz 100b +102: + .section .fixup,"ax" +103: addl %r8d,%edx /* ecx is zerorest also */ + jmp copy_user_handle_tail + .previous + + .section __ex_table,"a" + .align 8 + .quad 100b,103b + .quad 101b,103b + .previous +#endif + .endm + +/* Standard copy_to_user with segment limit checking */ ENTRY(copy_to_user) CFI_STARTPROC GET_THREAD_INFO(%rax) movq %rdi,%rcx addq %rdx,%rcx - jc bad_to_user - cmpq threadinfo_addr_limit(%rax),%rcx + jc bad_to_user + cmpq TI_addr_limit(%rax),%rcx jae bad_to_user - xorl %eax,%eax /* clear zero flag */ ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string CFI_ENDPROC -ENTRY(copy_user_generic) +/* Standard copy_from_user with segment limit checking */ +ENTRY(copy_from_user) CFI_STARTPROC - movl $1,%ecx /* set zero flag */ + GET_THREAD_INFO(%rax) + movq %rsi,%rcx + addq %rdx,%rcx + jc bad_from_user + cmpq TI_addr_limit(%rax),%rcx + jae bad_from_user ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string CFI_ENDPROC +ENDPROC(copy_from_user) -ENTRY(__copy_from_user_inatomic) +ENTRY(copy_user_generic) CFI_STARTPROC - xorl %ecx,%ecx /* clear zero flag */ ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string CFI_ENDPROC +ENDPROC(copy_user_generic) -/* Standard copy_from_user with segment limit checking */ -ENTRY(copy_from_user) +ENTRY(__copy_from_user_inatomic) CFI_STARTPROC - GET_THREAD_INFO(%rax) - movq %rsi,%rcx - addq %rdx,%rcx - jc bad_from_user - cmpq threadinfo_addr_limit(%rax),%rcx - jae bad_from_user - movl $1,%ecx /* set zero flag */ ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string CFI_ENDPROC -ENDPROC(copy_from_user) - +ENDPROC(__copy_from_user_inatomic) + .section .fixup,"ax" /* must zero dest */ +ENTRY(bad_from_user) bad_from_user: CFI_STARTPROC movl %edx,%ecx @@ -81,271 +111,158 @@ bad_from_user: rep stosb bad_to_user: - movl %edx,%eax + movl %edx,%eax ret CFI_ENDPROC -END(bad_from_user) +ENDPROC(bad_from_user) .previous - - + /* * copy_user_generic_unrolled - memory copy with exception handling. - * This version is for CPUs like P4 that don't have efficient micro code for rep movsq - * - * Input: + * This version is for CPUs like P4 that don't have efficient micro + * code for rep movsq + * + * Input: * rdi destination * rsi source * rdx count - * ecx zero flag -- if true zero destination on error * - * Output: - * eax uncopied bytes or 0 if successful. + * Output: + * eax uncopied bytes or 0 if successfull. */ ENTRY(copy_user_generic_unrolled) CFI_STARTPROC - pushq %rbx - CFI_ADJUST_CFA_OFFSET 8 - CFI_REL_OFFSET rbx, 0 - pushq %rcx - CFI_ADJUST_CFA_OFFSET 8 - CFI_REL_OFFSET rcx, 0 - xorl %eax,%eax /*zero for the exception handler */ - -#ifdef FIX_ALIGNMENT - /* check for bad alignment of destination */ - movl %edi,%ecx - andl $7,%ecx - jnz .Lbad_alignment -.Lafter_bad_alignment: -#endif - - movq %rdx,%rcx - - movl $64,%ebx - shrq $6,%rdx - decq %rdx - js .Lhandle_tail - - .p2align 4 -.Lloop: -.Ls1: movq (%rsi),%r11 -.Ls2: movq 1*8(%rsi),%r8 -.Ls3: movq 2*8(%rsi),%r9 -.Ls4: movq 3*8(%rsi),%r10 -.Ld1: movq %r11,(%rdi) -.Ld2: movq %r8,1*8(%rdi) -.Ld3: movq %r9,2*8(%rdi) -.Ld4: movq %r10,3*8(%rdi) - -.Ls5: movq 4*8(%rsi),%r11 -.Ls6: movq 5*8(%rsi),%r8 -.Ls7: movq 6*8(%rsi),%r9 -.Ls8: movq 7*8(%rsi),%r10 -.Ld5: movq %r11,4*8(%rdi) -.Ld6: movq %r8,5*8(%rdi) -.Ld7: movq %r9,6*8(%rdi) -.Ld8: movq %r10,7*8(%rdi) - - decq %rdx - + cmpl $8,%edx + jb 20f /* less then 8 bytes, go to byte copy loop */ + ALIGN_DESTINATION + movl %edx,%ecx + andl $63,%edx + shrl $6,%ecx + jz 17f +1: movq (%rsi),%r8 +2: movq 1*8(%rsi),%r9 +3: movq 2*8(%rsi),%r10 +4: movq 3*8(%rsi),%r11 +5: movq %r8,(%rdi) +6: movq %r9,1*8(%rdi) +7: movq %r10,2*8(%rdi) +8: movq %r11,3*8(%rdi) +9: movq 4*8(%rsi),%r8 +10: movq 5*8(%rsi),%r9 +11: movq 6*8(%rsi),%r10 +12: movq 7*8(%rsi),%r11 +13: movq %r8,4*8(%rdi) +14: movq %r9,5*8(%rdi) +15: movq %r10,6*8(%rdi) +16: movq %r11,7*8(%rdi) leaq 64(%rsi),%rsi leaq 64(%rdi),%rdi - - jns .Lloop - - .p2align 4 -.Lhandle_tail: - movl %ecx,%edx - andl $63,%ecx - shrl $3,%ecx - jz .Lhandle_7 - movl $8,%ebx - .p2align 4 -.Lloop_8: -.Ls9: movq (%rsi),%r8 -.Ld9: movq %r8,(%rdi) decl %ecx - leaq 8(%rdi),%rdi + jnz 1b +17: movl %edx,%ecx + andl $7,%edx + shrl $3,%ecx + jz 20f +18: movq (%rsi),%r8 +19: movq %r8,(%rdi) leaq 8(%rsi),%rsi - jnz .Lloop_8 - -.Lhandle_7: + leaq 8(%rdi),%rdi + decl %ecx + jnz 18b +20: andl %edx,%edx + jz 23f movl %edx,%ecx - andl $7,%ecx - jz .Lende - .p2align 4 -.Lloop_1: -.Ls10: movb (%rsi),%bl -.Ld10: movb %bl,(%rdi) - incq %rdi +21: movb (%rsi),%al +22: movb %al,(%rdi) incq %rsi + incq %rdi decl %ecx - jnz .Lloop_1 - - CFI_REMEMBER_STATE -.Lende: - popq %rcx - CFI_ADJUST_CFA_OFFSET -8 - CFI_RESTORE rcx - popq %rbx - CFI_ADJUST_CFA_OFFSET -8 - CFI_RESTORE rbx + jnz 21b +23: xor %eax,%eax ret - CFI_RESTORE_STATE -#ifdef FIX_ALIGNMENT - /* align destination */ - .p2align 4 -.Lbad_alignment: - movl $8,%r9d - subl %ecx,%r9d - movl %r9d,%ecx - cmpq %r9,%rdx - jz .Lhandle_7 - js .Lhandle_7 -.Lalign_1: -.Ls11: movb (%rsi),%bl -.Ld11: movb %bl,(%rdi) - incq %rsi - incq %rdi - decl %ecx - jnz .Lalign_1 - subq %r9,%rdx - jmp .Lafter_bad_alignment -#endif + .section .fixup,"ax" +30: shll $6,%ecx + addl %ecx,%edx + jmp 60f +40: lea (%rdx,%rcx,8),%rdx + jmp 60f +50: movl %ecx,%edx +60: jmp copy_user_handle_tail /* ecx is zerorest also */ + .previous - /* table sorted by exception address */ .section __ex_table,"a" .align 8 - .quad .Ls1,.Ls1e /* Ls1-Ls4 have copied zero bytes */ - .quad .Ls2,.Ls1e - .quad .Ls3,.Ls1e - .quad .Ls4,.Ls1e - .quad .Ld1,.Ls1e /* Ld1-Ld4 have copied 0-24 bytes */ - .quad .Ld2,.Ls2e - .quad .Ld3,.Ls3e - .quad .Ld4,.Ls4e - .quad .Ls5,.Ls5e /* Ls5-Ls8 have copied 32 bytes */ - .quad .Ls6,.Ls5e - .quad .Ls7,.Ls5e - .quad .Ls8,.Ls5e - .quad .Ld5,.Ls5e /* Ld5-Ld8 have copied 32-56 bytes */ - .quad .Ld6,.Ls6e - .quad .Ld7,.Ls7e - .quad .Ld8,.Ls8e - .quad .Ls9,.Le_quad - .quad .Ld9,.Le_quad - .quad .Ls10,.Le_byte - .quad .Ld10,.Le_byte -#ifdef FIX_ALIGNMENT - .quad .Ls11,.Lzero_rest - .quad .Ld11,.Lzero_rest -#endif - .quad .Le5,.Le_zero + .quad 1b,30b + .quad 2b,30b + .quad 3b,30b + .quad 4b,30b + .quad 5b,30b + .quad 6b,30b + .quad 7b,30b + .quad 8b,30b + .quad 9b,30b + .quad 10b,30b + .quad 11b,30b + .quad 12b,30b + .quad 13b,30b + .quad 14b,30b + .quad 15b,30b + .quad 16b,30b + .quad 18b,40b + .quad 19b,40b + .quad 21b,50b + .quad 22b,50b .previous - - /* eax: zero, ebx: 64 */ -.Ls1e: addl $8,%eax /* eax is bytes left uncopied within the loop (Ls1e: 64 .. Ls8e: 8) */ -.Ls2e: addl $8,%eax -.Ls3e: addl $8,%eax -.Ls4e: addl $8,%eax -.Ls5e: addl $8,%eax -.Ls6e: addl $8,%eax -.Ls7e: addl $8,%eax -.Ls8e: addl $8,%eax - addq %rbx,%rdi /* +64 */ - subq %rax,%rdi /* correct destination with computed offset */ - - shlq $6,%rdx /* loop counter * 64 (stride length) */ - addq %rax,%rdx /* add offset to loopcnt */ - andl $63,%ecx /* remaining bytes */ - addq %rcx,%rdx /* add them */ - jmp .Lzero_rest - - /* exception on quad word loop in tail handling */ - /* ecx: loopcnt/8, %edx: length, rdi: correct */ -.Le_quad: - shll $3,%ecx - andl $7,%edx - addl %ecx,%edx - /* edx: bytes to zero, rdi: dest, eax:zero */ -.Lzero_rest: - cmpl $0,(%rsp) - jz .Le_zero - movq %rdx,%rcx -.Le_byte: - xorl %eax,%eax -.Le5: rep - stosb - /* when there is another exception while zeroing the rest just return */ -.Le_zero: - movq %rdx,%rax - jmp .Lende CFI_ENDPROC -ENDPROC(copy_user_generic) +ENDPROC(copy_user_generic_unrolled) - - /* Some CPUs run faster using the string copy instructions. - This is also a lot simpler. Use them when possible. - Patch in jmps to this code instead of copying it fully - to avoid unwanted aliasing in the exception tables. */ - - /* rdi destination - * rsi source - * rdx count - * ecx zero flag - * - * Output: - * eax uncopied bytes or 0 if successfull. - * - * Only 4GB of copy is supported. This shouldn't be a problem - * because the kernel normally only writes from/to page sized chunks - * even if user space passed a longer buffer. - * And more would be dangerous because both Intel and AMD have - * errata with rep movsq > 4GB. If someone feels the need to fix - * this please consider this. - */ +/* Some CPUs run faster using the string copy instructions. + * This is also a lot simpler. Use them when possible. + * + * Only 4GB of copy is supported. This shouldn't be a problem + * because the kernel normally only writes from/to page sized chunks + * even if user space passed a longer buffer. + * And more would be dangerous because both Intel and AMD have + * errata with rep movsq > 4GB. If someone feels the need to fix + * this please consider this. + * + * Input: + * rdi destination + * rsi source + * rdx count + * + * Output: + * eax uncopied bytes or 0 if successful. + */ ENTRY(copy_user_generic_string) CFI_STARTPROC - movl %ecx,%r8d /* save zero flag */ + andl %edx,%edx + jz 4f + cmpl $8,%edx + jb 2f /* less than 8 bytes, go to byte copy loop */ + ALIGN_DESTINATION movl %edx,%ecx shrl $3,%ecx - andl $7,%edx - jz 10f -1: rep - movsq - movl %edx,%ecx -2: rep - movsb -9: movl %ecx,%eax - ret - - /* multiple of 8 byte */ -10: rep + andl $7,%edx +1: rep movsq - xor %eax,%eax +2: movl %edx,%ecx +3: rep + movsb +4: xorl %eax,%eax ret - /* exception handling */ -3: lea (%rdx,%rcx,8),%rax /* exception on quad loop */ - jmp 6f -5: movl %ecx,%eax /* exception on byte loop */ - /* eax: left over bytes */ -6: testl %r8d,%r8d /* zero flag set? */ - jz 7f - movl %eax,%ecx /* initialize x86 loop counter */ - push %rax - xorl %eax,%eax -8: rep - stosb /* zero the rest */ -11: pop %rax -7: ret - CFI_ENDPROC -END(copy_user_generic_c) + .section .fixup,"ax" +11: lea (%rdx,%rcx,8),%rcx +12: movl %ecx,%edx /* ecx is zerorest also */ + jmp copy_user_handle_tail + .previous .section __ex_table,"a" - .quad 1b,3b - .quad 2b,5b - .quad 8b,11b - .quad 10b,3b + .align 8 + .quad 1b,11b + .quad 3b,12b .previous + CFI_ENDPROC +ENDPROC(copy_user_generic_string) diff --git a/arch/x86/lib/copy_user_nocache_64.S b/arch/x86/lib/copy_user_nocache_64.S index 9d3d1ab8376..40e0e309d27 100644 --- a/arch/x86/lib/copy_user_nocache_64.S +++ b/arch/x86/lib/copy_user_nocache_64.S @@ -1,4 +1,6 @@ -/* Copyright 2002 Andi Kleen, SuSE Labs. +/* + * Copyright 2008 Vitaly Mayatskikh <vmayatsk@redhat.com> + * Copyright 2002 Andi Kleen, SuSE Labs. * Subject to the GNU Public License v2. * * Functions to copy from and to user space. @@ -12,204 +14,125 @@ #include <asm/current.h> #include <asm/asm-offsets.h> #include <asm/thread_info.h> -#include <asm/cpufeature.h> - -/* - * copy_user_nocache - Uncached memory copy with exception handling - * This will force destination/source out of cache for more performance. - * - * Input: - * rdi destination - * rsi source - * rdx count - * rcx zero flag when 1 zero on exception - * - * Output: - * eax uncopied bytes or 0 if successful. - */ -ENTRY(__copy_user_nocache) - CFI_STARTPROC - pushq %rbx - CFI_ADJUST_CFA_OFFSET 8 - CFI_REL_OFFSET rbx, 0 - pushq %rcx /* save zero flag */ - CFI_ADJUST_CFA_OFFSET 8 - CFI_REL_OFFSET rcx, 0 - - xorl %eax,%eax /* zero for the exception handler */ + .macro ALIGN_DESTINATION #ifdef FIX_ALIGNMENT /* check for bad alignment of destination */ movl %edi,%ecx andl $7,%ecx - jnz .Lbad_alignment -.Lafter_bad_alignment: -#endif - - movq %rdx,%rcx - - movl $64,%ebx - shrq $6,%rdx - decq %rdx - js .Lhandle_tail - - .p2align 4 -.Lloop: -.Ls1: movq (%rsi),%r11 -.Ls2: movq 1*8(%rsi),%r8 -.Ls3: movq 2*8(%rsi),%r9 -.Ls4: movq 3*8(%rsi),%r10 -.Ld1: movnti %r11,(%rdi) -.Ld2: movnti %r8,1*8(%rdi) -.Ld3: movnti %r9,2*8(%rdi) -.Ld4: movnti %r10,3*8(%rdi) - -.Ls5: movq 4*8(%rsi),%r11 -.Ls6: movq 5*8(%rsi),%r8 -.Ls7: movq 6*8(%rsi),%r9 -.Ls8: movq 7*8(%rsi),%r10 -.Ld5: movnti %r11,4*8(%rdi) -.Ld6: movnti %r8,5*8(%rdi) -.Ld7: movnti %r9,6*8(%rdi) -.Ld8: movnti %r10,7*8(%rdi) + jz 102f /* already aligned */ + subl $8,%ecx + negl %ecx + subl %ecx,%edx +100: movb (%rsi),%al +101: movb %al,(%rdi) + incq %rsi + incq %rdi + decl %ecx + jnz 100b +102: + .section .fixup,"ax" +103: addl %r8d,%edx /* ecx is zerorest also */ + jmp copy_user_handle_tail + .previous - dec %rdx + .section __ex_table,"a" + .align 8 + .quad 100b,103b + .quad 101b,103b + .previous +#endif + .endm +/* + * copy_user_nocache - Uncached memory copy with exception handling + * This will force destination/source out of cache for more performance. + */ +ENTRY(__copy_user_nocache) + CFI_STARTPROC + cmpl $8,%edx + jb 20f /* less then 8 bytes, go to byte copy loop */ + ALIGN_DESTINATION + movl %edx,%ecx + andl $63,%edx + shrl $6,%ecx + jz 17f +1: movq (%rsi),%r8 +2: movq 1*8(%rsi),%r9 +3: movq 2*8(%rsi),%r10 +4: movq 3*8(%rsi),%r11 +5: movnti %r8,(%rdi) +6: movnti %r9,1*8(%rdi) +7: movnti %r10,2*8(%rdi) +8: movnti %r11,3*8(%rdi) +9: movq 4*8(%rsi),%r8 +10: movq 5*8(%rsi),%r9 +11: movq 6*8(%rsi),%r10 +12: movq 7*8(%rsi),%r11 +13: movnti %r8,4*8(%rdi) +14: movnti %r9,5*8(%rdi) +15: movnti %r10,6*8(%rdi) +16: movnti %r11,7*8(%rdi) leaq 64(%rsi),%rsi leaq 64(%rdi),%rdi - - jns .Lloop - - .p2align 4 -.Lhandle_tail: - movl %ecx,%edx - andl $63,%ecx - shrl $3,%ecx - jz .Lhandle_7 - movl $8,%ebx - .p2align 4 -.Lloop_8: -.Ls9: movq (%rsi),%r8 -.Ld9: movnti %r8,(%rdi) decl %ecx - leaq 8(%rdi),%rdi + jnz 1b +17: movl %edx,%ecx + andl $7,%edx + shrl $3,%ecx + jz 20f +18: movq (%rsi),%r8 +19: movnti %r8,(%rdi) leaq 8(%rsi),%rsi - jnz .Lloop_8 - -.Lhandle_7: + leaq 8(%rdi),%rdi + decl %ecx + jnz 18b +20: andl %edx,%edx + jz 23f movl %edx,%ecx - andl $7,%ecx - jz .Lende - .p2align 4 -.Lloop_1: -.Ls10: movb (%rsi),%bl -.Ld10: movb %bl,(%rdi) - incq %rdi +21: movb (%rsi),%al +22: movb %al,(%rdi) incq %rsi + incq %rdi decl %ecx - jnz .Lloop_1 - - CFI_REMEMBER_STATE -.Lende: - popq %rcx - CFI_ADJUST_CFA_OFFSET -8 - CFI_RESTORE %rcx - popq %rbx - CFI_ADJUST_CFA_OFFSET -8 - CFI_RESTORE rbx + jnz 21b +23: xorl %eax,%eax sfence ret - CFI_RESTORE_STATE -#ifdef FIX_ALIGNMENT - /* align destination */ - .p2align 4 -.Lbad_alignment: - movl $8,%r9d - subl %ecx,%r9d - movl %r9d,%ecx - cmpq %r9,%rdx - jz .Lhandle_7 - js .Lhandle_7 -.Lalign_1: -.Ls11: movb (%rsi),%bl -.Ld11: movb %bl,(%rdi) - incq %rsi - incq %rdi - decl %ecx - jnz .Lalign_1 - subq %r9,%rdx - jmp .Lafter_bad_alignment -#endif + .section .fixup,"ax" +30: shll $6,%ecx + addl %ecx,%edx + jmp 60f +40: lea (%rdx,%rcx,8),%rdx + jmp 60f +50: movl %ecx,%edx +60: sfence + movl %r8d,%ecx + jmp copy_user_handle_tail + .previous - /* table sorted by exception address */ .section __ex_table,"a" - .align 8 - .quad .Ls1,.Ls1e /* .Ls[1-4] - 0 bytes copied */ - .quad .Ls2,.Ls1e - .quad .Ls3,.Ls1e - .quad .Ls4,.Ls1e - .quad .Ld1,.Ls1e /* .Ld[1-4] - 0..24 bytes coped */ - .quad .Ld2,.Ls2e - .quad .Ld3,.Ls3e - .quad .Ld4,.Ls4e - .quad .Ls5,.Ls5e /* .Ls[5-8] - 32 bytes copied */ - .quad .Ls6,.Ls5e - .quad .Ls7,.Ls5e - .quad .Ls8,.Ls5e - .quad .Ld5,.Ls5e /* .Ld[5-8] - 32..56 bytes copied */ - .quad .Ld6,.Ls6e - .quad .Ld7,.Ls7e - .quad .Ld8,.Ls8e - .quad .Ls9,.Le_quad - .quad .Ld9,.Le_quad - .quad .Ls10,.Le_byte - .quad .Ld10,.Le_byte -#ifdef FIX_ALIGNMENT - .quad .Ls11,.Lzero_rest - .quad .Ld11,.Lzero_rest -#endif - .quad .Le5,.Le_zero + .quad 1b,30b + .quad 2b,30b + .quad 3b,30b + .quad 4b,30b + .quad 5b,30b + .quad 6b,30b + .quad 7b,30b + .quad 8b,30b + .quad 9b,30b + .quad 10b,30b + .quad 11b,30b + .quad 12b,30b + .quad 13b,30b + .quad 14b,30b + .quad 15b,30b + .quad 16b,30b + .quad 18b,40b + .quad 19b,40b + .quad 21b,50b + .quad 22b,50b .previous - - /* eax: zero, ebx: 64 */ -.Ls1e: addl $8,%eax /* eax: bytes left uncopied: Ls1e: 64 .. Ls8e: 8 */ -.Ls2e: addl $8,%eax -.Ls3e: addl $8,%eax -.Ls4e: addl $8,%eax -.Ls5e: addl $8,%eax -.Ls6e: addl $8,%eax -.Ls7e: addl $8,%eax -.Ls8e: addl $8,%eax - addq %rbx,%rdi /* +64 */ - subq %rax,%rdi /* correct destination with computed offset */ - - shlq $6,%rdx /* loop counter * 64 (stride length) */ - addq %rax,%rdx /* add offset to loopcnt */ - andl $63,%ecx /* remaining bytes */ - addq %rcx,%rdx /* add them */ - jmp .Lzero_rest - - /* exception on quad word loop in tail handling */ - /* ecx: loopcnt/8, %edx: length, rdi: correct */ -.Le_quad: - shll $3,%ecx - andl $7,%edx - addl %ecx,%edx - /* edx: bytes to zero, rdi: dest, eax:zero */ -.Lzero_rest: - cmpl $0,(%rsp) /* zero flag set? */ - jz .Le_zero - movq %rdx,%rcx -.Le_byte: - xorl %eax,%eax -.Le5: rep - stosb - /* when there is another exception while zeroing the rest just return */ -.Le_zero: - movq %rdx,%rax - jmp .Lende CFI_ENDPROC ENDPROC(__copy_user_nocache) - - diff --git a/arch/x86/lib/delay_32.c b/arch/x86/lib/delay.c index d710f2d167b..f4568605d7d 100644 --- a/arch/x86/lib/delay_32.c +++ b/arch/x86/lib/delay.c @@ -3,6 +3,7 @@ * * Copyright (C) 1993 Linus Torvalds * Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz> + * Copyright (C) 2008 Jiri Hladky <hladky _dot_ jiri _at_ gmail _dot_ com> * * The __delay function must _NOT_ be inlined as its execution time * depends wildly on alignment on many x86 processors. The additional @@ -28,16 +29,22 @@ /* simple loop based delay: */ static void delay_loop(unsigned long loops) { - int d0; - - __asm__ __volatile__( - "\tjmp 1f\n" - ".align 16\n" - "1:\tjmp 2f\n" - ".align 16\n" - "2:\tdecl %0\n\tjns 2b" - :"=&a" (d0) - :"0" (loops)); + asm volatile( + " test %0,%0 \n" + " jz 3f \n" + " jmp 1f \n" + + ".align 16 \n" + "1: jmp 2f \n" + + ".align 16 \n" + "2: dec %0 \n" + " jnz 2b \n" + "3: dec %0 \n" + + : /* we don't need output */ + :"a" (loops) + ); } /* TSC based delay: */ @@ -91,7 +98,7 @@ void use_tsc_delay(void) int __devinit read_current_timer(unsigned long *timer_val) { if (delay_fn == delay_tsc) { - rdtscl(*timer_val); + rdtscll(*timer_val); return 0; } return -1; @@ -101,31 +108,30 @@ void __delay(unsigned long loops) { delay_fn(loops); } +EXPORT_SYMBOL(__delay); inline void __const_udelay(unsigned long xloops) { int d0; xloops *= 4; - __asm__("mull %0" + asm("mull %%edx" :"=d" (xloops), "=&a" (d0) :"1" (xloops), "0" (cpu_data(raw_smp_processor_id()).loops_per_jiffy * (HZ/4))); __delay(++xloops); } +EXPORT_SYMBOL(__const_udelay); void __udelay(unsigned long usecs) { __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */ } +EXPORT_SYMBOL(__udelay); void __ndelay(unsigned long nsecs) { __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */ } - -EXPORT_SYMBOL(__delay); -EXPORT_SYMBOL(__const_udelay); -EXPORT_SYMBOL(__udelay); EXPORT_SYMBOL(__ndelay); diff --git a/arch/x86/lib/delay_64.c b/arch/x86/lib/delay_64.c deleted file mode 100644 index 4c441be9264..00000000000 --- a/arch/x86/lib/delay_64.c +++ /dev/null @@ -1,85 +0,0 @@ -/* - * Precise Delay Loops for x86-64 - * - * Copyright (C) 1993 Linus Torvalds - * Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz> - * - * The __delay function must _NOT_ be inlined as its execution time - * depends wildly on alignment on many x86 processors. - */ - -#include <linux/module.h> -#include <linux/sched.h> -#include <linux/timex.h> -#include <linux/preempt.h> -#include <linux/delay.h> -#include <linux/init.h> - -#include <asm/delay.h> -#include <asm/msr.h> - -#ifdef CONFIG_SMP -#include <asm/smp.h> -#endif - -int __devinit read_current_timer(unsigned long *timer_value) -{ - rdtscll(*timer_value); - return 0; -} - -void __delay(unsigned long loops) -{ - unsigned bclock, now; - int cpu; - - preempt_disable(); - cpu = smp_processor_id(); - rdtscl(bclock); - for (;;) { - rdtscl(now); - if ((now - bclock) >= loops) - break; - - /* Allow RT tasks to run */ - preempt_enable(); - rep_nop(); - preempt_disable(); - - /* - * It is possible that we moved to another CPU, and - * since TSC's are per-cpu we need to calculate - * that. The delay must guarantee that we wait "at - * least" the amount of time. Being moved to another - * CPU could make the wait longer but we just need to - * make sure we waited long enough. Rebalance the - * counter for this CPU. - */ - if (unlikely(cpu != smp_processor_id())) { - loops -= (now - bclock); - cpu = smp_processor_id(); - rdtscl(bclock); - } - } - preempt_enable(); -} -EXPORT_SYMBOL(__delay); - -inline void __const_udelay(unsigned long xloops) -{ - __delay(((xloops * HZ * - cpu_data(raw_smp_processor_id()).loops_per_jiffy) >> 32) + 1); -} -EXPORT_SYMBOL(__const_udelay); - -void __udelay(unsigned long usecs) -{ - __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */ -} -EXPORT_SYMBOL(__udelay); - -void __ndelay(unsigned long nsecs) -{ - __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */ -} -EXPORT_SYMBOL(__ndelay); diff --git a/arch/x86/lib/getuser_64.S b/arch/x86/lib/getuser.S index 5448876261f..ad374003742 100644 --- a/arch/x86/lib/getuser_64.S +++ b/arch/x86/lib/getuser.S @@ -3,6 +3,7 @@ * * (C) Copyright 1998 Linus Torvalds * (C) Copyright 2005 Andi Kleen + * (C) Copyright 2008 Glauber Costa * * These functions have a non-standard call interface * to make them more efficient, especially as they @@ -13,14 +14,13 @@ /* * __get_user_X * - * Inputs: %rcx contains the address. + * Inputs: %[r|e]ax contains the address. * The register is modified, but all changes are undone * before returning because the C code doesn't know about it. * - * Outputs: %rax is error code (0 or -EFAULT) - * %rdx contains zero-extended value - * - * %r8 is destroyed. + * Outputs: %[r|e]ax is error code (0 or -EFAULT) + * %[r|e]dx contains zero-extended value + * * * These functions should not modify any other registers, * as they get called from within inline assembly. @@ -32,78 +32,73 @@ #include <asm/errno.h> #include <asm/asm-offsets.h> #include <asm/thread_info.h> +#include <asm/asm.h> .text ENTRY(__get_user_1) CFI_STARTPROC - GET_THREAD_INFO(%r8) - cmpq threadinfo_addr_limit(%r8),%rcx + GET_THREAD_INFO(%_ASM_DX) + cmp TI_addr_limit(%_ASM_DX),%_ASM_AX jae bad_get_user -1: movzb (%rcx),%edx - xorl %eax,%eax +1: movzb (%_ASM_AX),%edx + xor %eax,%eax ret CFI_ENDPROC ENDPROC(__get_user_1) ENTRY(__get_user_2) CFI_STARTPROC - GET_THREAD_INFO(%r8) - addq $1,%rcx - jc 20f - cmpq threadinfo_addr_limit(%r8),%rcx - jae 20f - decq %rcx -2: movzwl (%rcx),%edx - xorl %eax,%eax + add $1,%_ASM_AX + jc bad_get_user + GET_THREAD_INFO(%_ASM_DX) + cmp TI_addr_limit(%_ASM_DX),%_ASM_AX + jae bad_get_user +2: movzwl -1(%_ASM_AX),%edx + xor %eax,%eax ret -20: decq %rcx - jmp bad_get_user CFI_ENDPROC ENDPROC(__get_user_2) ENTRY(__get_user_4) CFI_STARTPROC - GET_THREAD_INFO(%r8) - addq $3,%rcx - jc 30f - cmpq threadinfo_addr_limit(%r8),%rcx - jae 30f - subq $3,%rcx -3: movl (%rcx),%edx - xorl %eax,%eax + add $3,%_ASM_AX + jc bad_get_user + GET_THREAD_INFO(%_ASM_DX) + cmp TI_addr_limit(%_ASM_DX),%_ASM_AX + jae bad_get_user +3: mov -3(%_ASM_AX),%edx + xor %eax,%eax ret -30: subq $3,%rcx - jmp bad_get_user CFI_ENDPROC ENDPROC(__get_user_4) +#ifdef CONFIG_X86_64 ENTRY(__get_user_8) CFI_STARTPROC - GET_THREAD_INFO(%r8) - addq $7,%rcx - jc 40f - cmpq threadinfo_addr_limit(%r8),%rcx - jae 40f - subq $7,%rcx -4: movq (%rcx),%rdx - xorl %eax,%eax + add $7,%_ASM_AX + jc bad_get_user + GET_THREAD_INFO(%_ASM_DX) + cmp TI_addr_limit(%_ASM_DX),%_ASM_AX + jae bad_get_user +4: movq -7(%_ASM_AX),%_ASM_DX + xor %eax,%eax ret -40: subq $7,%rcx - jmp bad_get_user CFI_ENDPROC ENDPROC(__get_user_8) +#endif bad_get_user: CFI_STARTPROC - xorl %edx,%edx - movq $(-EFAULT),%rax + xor %edx,%edx + mov $(-EFAULT),%_ASM_AX ret CFI_ENDPROC END(bad_get_user) .section __ex_table,"a" - .quad 1b,bad_get_user - .quad 2b,bad_get_user - .quad 3b,bad_get_user - .quad 4b,bad_get_user -.previous + _ASM_PTR 1b,bad_get_user + _ASM_PTR 2b,bad_get_user + _ASM_PTR 3b,bad_get_user +#ifdef CONFIG_X86_64 + _ASM_PTR 4b,bad_get_user +#endif diff --git a/arch/x86/lib/getuser_32.S b/arch/x86/lib/getuser_32.S deleted file mode 100644 index 6d84b53f12a..00000000000 --- a/arch/x86/lib/getuser_32.S +++ /dev/null @@ -1,78 +0,0 @@ -/* - * __get_user functions. - * - * (C) Copyright 1998 Linus Torvalds - * - * These functions have a non-standard call interface - * to make them more efficient, especially as they - * return an error value in addition to the "real" - * return value. - */ -#include <linux/linkage.h> -#include <asm/dwarf2.h> -#include <asm/thread_info.h> - - -/* - * __get_user_X - * - * Inputs: %eax contains the address - * - * Outputs: %eax is error code (0 or -EFAULT) - * %edx contains zero-extended value - * - * These functions should not modify any other registers, - * as they get called from within inline assembly. - */ - -.text -ENTRY(__get_user_1) - CFI_STARTPROC - GET_THREAD_INFO(%edx) - cmpl TI_addr_limit(%edx),%eax - jae bad_get_user -1: movzbl (%eax),%edx - xorl %eax,%eax - ret - CFI_ENDPROC -ENDPROC(__get_user_1) - -ENTRY(__get_user_2) - CFI_STARTPROC - addl $1,%eax - jc bad_get_user - GET_THREAD_INFO(%edx) - cmpl TI_addr_limit(%edx),%eax - jae bad_get_user -2: movzwl -1(%eax),%edx - xorl %eax,%eax - ret - CFI_ENDPROC -ENDPROC(__get_user_2) - -ENTRY(__get_user_4) - CFI_STARTPROC - addl $3,%eax - jc bad_get_user - GET_THREAD_INFO(%edx) - cmpl TI_addr_limit(%edx),%eax - jae bad_get_user -3: movl -3(%eax),%edx - xorl %eax,%eax - ret - CFI_ENDPROC -ENDPROC(__get_user_4) - -bad_get_user: - CFI_STARTPROC - xorl %edx,%edx - movl $-14,%eax - ret - CFI_ENDPROC -END(bad_get_user) - -.section __ex_table,"a" - .long 1b,bad_get_user - .long 2b,bad_get_user - .long 3b,bad_get_user -.previous diff --git a/arch/x86/lib/putuser_32.S b/arch/x86/lib/putuser.S index f58fba109d1..36b0d15ae6e 100644 --- a/arch/x86/lib/putuser_32.S +++ b/arch/x86/lib/putuser.S @@ -2,6 +2,8 @@ * __put_user functions. * * (C) Copyright 2005 Linus Torvalds + * (C) Copyright 2005 Andi Kleen + * (C) Copyright 2008 Glauber Costa * * These functions have a non-standard call interface * to make them more efficient, especially as they @@ -11,6 +13,8 @@ #include <linux/linkage.h> #include <asm/dwarf2.h> #include <asm/thread_info.h> +#include <asm/errno.h> +#include <asm/asm.h> /* @@ -26,73 +30,68 @@ */ #define ENTER CFI_STARTPROC ; \ - pushl %ebx ; \ - CFI_ADJUST_CFA_OFFSET 4 ; \ - CFI_REL_OFFSET ebx, 0 ; \ - GET_THREAD_INFO(%ebx) -#define EXIT popl %ebx ; \ - CFI_ADJUST_CFA_OFFSET -4 ; \ - CFI_RESTORE ebx ; \ - ret ; \ + GET_THREAD_INFO(%_ASM_BX) +#define EXIT ret ; \ CFI_ENDPROC .text ENTRY(__put_user_1) ENTER - cmpl TI_addr_limit(%ebx),%ecx + cmp TI_addr_limit(%_ASM_BX),%_ASM_CX jae bad_put_user -1: movb %al,(%ecx) - xorl %eax,%eax +1: movb %al,(%_ASM_CX) + xor %eax,%eax EXIT ENDPROC(__put_user_1) ENTRY(__put_user_2) ENTER - movl TI_addr_limit(%ebx),%ebx - subl $1,%ebx - cmpl %ebx,%ecx + mov TI_addr_limit(%_ASM_BX),%_ASM_BX + sub $1,%_ASM_BX + cmp %_ASM_BX,%_ASM_CX jae bad_put_user -2: movw %ax,(%ecx) - xorl %eax,%eax +2: movw %ax,(%_ASM_CX) + xor %eax,%eax EXIT ENDPROC(__put_user_2) ENTRY(__put_user_4) ENTER - movl TI_addr_limit(%ebx),%ebx - subl $3,%ebx - cmpl %ebx,%ecx + mov TI_addr_limit(%_ASM_BX),%_ASM_BX + sub $3,%_ASM_BX + cmp %_ASM_BX,%_ASM_CX jae bad_put_user -3: movl %eax,(%ecx) - xorl %eax,%eax +3: movl %eax,(%_ASM_CX) + xor %eax,%eax EXIT ENDPROC(__put_user_4) ENTRY(__put_user_8) ENTER - movl TI_addr_limit(%ebx),%ebx - subl $7,%ebx - cmpl %ebx,%ecx + mov TI_addr_limit(%_ASM_BX),%_ASM_BX + sub $7,%_ASM_BX + cmp %_ASM_BX,%_ASM_CX jae bad_put_user -4: movl %eax,(%ecx) -5: movl %edx,4(%ecx) - xorl %eax,%eax +4: mov %_ASM_AX,(%_ASM_CX) +#ifdef CONFIG_X86_32 +5: movl %edx,4(%_ASM_CX) +#endif + xor %eax,%eax EXIT ENDPROC(__put_user_8) bad_put_user: - CFI_STARTPROC simple - CFI_DEF_CFA esp, 2*4 - CFI_OFFSET eip, -1*4 - CFI_OFFSET ebx, -2*4 - movl $-14,%eax + CFI_STARTPROC + movl $-EFAULT,%eax EXIT END(bad_put_user) .section __ex_table,"a" - .long 1b,bad_put_user - .long 2b,bad_put_user - .long 3b,bad_put_user - .long 4b,bad_put_user - .long 5b,bad_put_user + _ASM_PTR 1b,bad_put_user + _ASM_PTR 2b,bad_put_user + _ASM_PTR 3b,bad_put_user + _ASM_PTR 4b,bad_put_user +#ifdef CONFIG_X86_32 + _ASM_PTR 5b,bad_put_user +#endif .previous diff --git a/arch/x86/lib/putuser_64.S b/arch/x86/lib/putuser_64.S deleted file mode 100644 index 4989f5a8fa9..00000000000 --- a/arch/x86/lib/putuser_64.S +++ /dev/null @@ -1,106 +0,0 @@ -/* - * __put_user functions. - * - * (C) Copyright 1998 Linus Torvalds - * (C) Copyright 2005 Andi Kleen - * - * These functions have a non-standard call interface - * to make them more efficient, especially as they - * return an error value in addition to the "real" - * return value. - */ - -/* - * __put_user_X - * - * Inputs: %rcx contains the address - * %rdx contains new value - * - * Outputs: %rax is error code (0 or -EFAULT) - * - * %r8 is destroyed. - * - * These functions should not modify any other registers, - * as they get called from within inline assembly. - */ - -#include <linux/linkage.h> -#include <asm/dwarf2.h> -#include <asm/page.h> -#include <asm/errno.h> -#include <asm/asm-offsets.h> -#include <asm/thread_info.h> - - .text -ENTRY(__put_user_1) - CFI_STARTPROC - GET_THREAD_INFO(%r8) - cmpq threadinfo_addr_limit(%r8),%rcx - jae bad_put_user -1: movb %dl,(%rcx) - xorl %eax,%eax - ret - CFI_ENDPROC -ENDPROC(__put_user_1) - -ENTRY(__put_user_2) - CFI_STARTPROC - GET_THREAD_INFO(%r8) - addq $1,%rcx - jc 20f - cmpq threadinfo_addr_limit(%r8),%rcx - jae 20f - decq %rcx -2: movw %dx,(%rcx) - xorl %eax,%eax - ret -20: decq %rcx - jmp bad_put_user - CFI_ENDPROC -ENDPROC(__put_user_2) - -ENTRY(__put_user_4) - CFI_STARTPROC - GET_THREAD_INFO(%r8) - addq $3,%rcx - jc 30f - cmpq threadinfo_addr_limit(%r8),%rcx - jae 30f - subq $3,%rcx -3: movl %edx,(%rcx) - xorl %eax,%eax - ret -30: subq $3,%rcx - jmp bad_put_user - CFI_ENDPROC -ENDPROC(__put_user_4) - -ENTRY(__put_user_8) - CFI_STARTPROC - GET_THREAD_INFO(%r8) - addq $7,%rcx - jc 40f - cmpq threadinfo_addr_limit(%r8),%rcx - jae 40f - subq $7,%rcx -4: movq %rdx,(%rcx) - xorl %eax,%eax - ret -40: subq $7,%rcx - jmp bad_put_user - CFI_ENDPROC -ENDPROC(__put_user_8) - -bad_put_user: - CFI_STARTPROC - movq $(-EFAULT),%rax - ret - CFI_ENDPROC -END(bad_put_user) - -.section __ex_table,"a" - .quad 1b,bad_put_user - .quad 2b,bad_put_user - .quad 3b,bad_put_user - .quad 4b,bad_put_user -.previous diff --git a/arch/x86/lib/thunk_32.S b/arch/x86/lib/thunk_32.S new file mode 100644 index 00000000000..650b11e00ec --- /dev/null +++ b/arch/x86/lib/thunk_32.S @@ -0,0 +1,47 @@ +/* + * Trampoline to trace irqs off. (otherwise CALLER_ADDR1 might crash) + * Copyright 2008 by Steven Rostedt, Red Hat, Inc + * (inspired by Andi Kleen's thunk_64.S) + * Subject to the GNU public license, v.2. No warranty of any kind. + */ + + #include <linux/linkage.h> + +#define ARCH_TRACE_IRQS_ON \ + pushl %eax; \ + pushl %ecx; \ + pushl %edx; \ + call trace_hardirqs_on; \ + popl %edx; \ + popl %ecx; \ + popl %eax; + +#define ARCH_TRACE_IRQS_OFF \ + pushl %eax; \ + pushl %ecx; \ + pushl %edx; \ + call trace_hardirqs_off; \ + popl %edx; \ + popl %ecx; \ + popl %eax; + +#ifdef CONFIG_TRACE_IRQFLAGS + /* put return address in eax (arg1) */ + .macro thunk_ra name,func + .globl \name +\name: + pushl %eax + pushl %ecx + pushl %edx + /* Place EIP in the arg1 */ + movl 3*4(%esp), %eax + call \func + popl %edx + popl %ecx + popl %eax + ret + .endm + + thunk_ra trace_hardirqs_on_thunk,trace_hardirqs_on_caller + thunk_ra trace_hardirqs_off_thunk,trace_hardirqs_off_caller +#endif diff --git a/arch/x86/lib/thunk_64.S b/arch/x86/lib/thunk_64.S index e009251d4e9..bf9a7d5a542 100644 --- a/arch/x86/lib/thunk_64.S +++ b/arch/x86/lib/thunk_64.S @@ -2,6 +2,7 @@ * Save registers before calling assembly functions. This avoids * disturbance of register allocation in some inline assembly constructs. * Copyright 2001,2002 by Andi Kleen, SuSE Labs. + * Added trace_hardirqs callers - Copyright 2007 Steven Rostedt, Red Hat, Inc. * Subject to the GNU public license, v.2. No warranty of any kind. */ @@ -42,8 +43,22 @@ #endif #ifdef CONFIG_TRACE_IRQFLAGS - thunk trace_hardirqs_on_thunk,trace_hardirqs_on - thunk trace_hardirqs_off_thunk,trace_hardirqs_off + /* put return address in rdi (arg1) */ + .macro thunk_ra name,func + .globl \name +\name: + CFI_STARTPROC + SAVE_ARGS + /* SAVE_ARGS pushs 9 elements */ + /* the next element would be the rip */ + movq 9*8(%rsp), %rdi + call \func + jmp restore + CFI_ENDPROC + .endm + + thunk_ra trace_hardirqs_on_thunk,trace_hardirqs_on_caller + thunk_ra trace_hardirqs_off_thunk,trace_hardirqs_off_caller #endif #ifdef CONFIG_DEBUG_LOCK_ALLOC diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c index 0c89d1bb028..f4df6e7c718 100644 --- a/arch/x86/lib/usercopy_64.c +++ b/arch/x86/lib/usercopy_64.c @@ -158,3 +158,26 @@ unsigned long copy_in_user(void __user *to, const void __user *from, unsigned le } EXPORT_SYMBOL(copy_in_user); +/* + * Try to copy last bytes and clear the rest if needed. + * Since protection fault in copy_from/to_user is not a normal situation, + * it is not necessary to optimize tail handling. + */ +unsigned long +copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest) +{ + char c; + unsigned zero_len; + + for (; len; --len) { + if (__get_user_nocheck(c, from++, sizeof(char))) + break; + if (__put_user_nocheck(c, to++, sizeof(char))) + break; + } + + for (c = 0, zero_len = len; zerorest && zero_len; --zero_len) + if (__put_user_nocheck(c, to++, sizeof(char))) + break; + return len; +} |