From 3cf1291d2e64aa741ae520363f8710f2c1e80127 Mon Sep 17 00:00:00 2001 From: Mateusz Guzik Date: Fri, 12 Oct 2018 21:59:09 +0000 Subject: amd64: employ MEMMOVE in copyin/copyout See r339205 for justification. Reviewed by: kib Approved by: re (gjb) Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17526 --- sys/amd64/amd64/support.S | 94 +++++++++++++++++++---------------------------- 1 file changed, 37 insertions(+), 57 deletions(-) (limited to 'sys') diff --git a/sys/amd64/amd64/support.S b/sys/amd64/amd64/support.S index 7a7a2f4611e9..fac0fb88a000 100644 --- a/sys/amd64/amd64/support.S +++ b/sys/amd64/amd64/support.S @@ -576,14 +576,27 @@ END(fillw) .endif .endm +.macro COPYINOUT_BEGIN +.endm + +.macro COPYINOUT_END + movq %rax,PCB_ONFAULT(%r11) + POP_FRAME_POINTER +.endm + +.macro COPYINOUT_SMAP_END + SMAP_ENABLE smap=1 + COPYINOUT_END +.endm + /* * copyout(from_kernel, to_user, len) * %rdi, %rsi, %rdx */ .macro COPYOUT smap erms PUSH_FRAME_POINTER - movq PCPU(CURPCB),%r9 - movq $copy_fault,PCB_ONFAULT(%r9) + movq PCPU(CURPCB),%r11 + movq $copy_fault,PCB_ONFAULT(%r11) /* * Check explicitly for non-user addresses. If 486 write protection @@ -609,43 +622,27 @@ END(fillw) ja copy_fault /* - * Set up arguments for rep movs*. + * Set return value to zero. Remaining failure mode goes through + * copy_fault. + */ + xorl %eax,%eax + + /* + * Set up arguments for MEMMOVE. */ movq %rdi,%r8 movq %rsi,%rdi movq %r8,%rsi movq %rdx,%rcx - /* - * Set return value to zero. Remaining failure mode goes through - * copy_fault. - */ - xorl %eax,%eax SMAP_DISABLE \smap -.if \erms == 0 - cmpq $15,%rcx - jbe 1f - shrq $3,%rcx - rep - movsq - movb %dl,%cl - andb $7,%cl - jne 1f - SMAP_ENABLE \smap - movq %rax,PCB_ONFAULT(%r9) - POP_FRAME_POINTER - ret - ALIGN_TEXT -1: +.if \smap == 1 + MEMMOVE erms=\erms overlap=0 begin=COPYINOUT_BEGIN end=COPYINOUT_SMAP_END +.else + MEMMOVE erms=\erms overlap=0 begin=COPYINOUT_BEGIN end=COPYINOUT_END .endif - rep - movsb - - SMAP_ENABLE \smap - movq %rax,PCB_ONFAULT(%r9) - POP_FRAME_POINTER - ret + /* NOTREACHED */ .endm ENTRY(copyout_nosmap_std) @@ -670,8 +667,8 @@ END(copyout_smap_erms) */ .macro COPYIN smap erms PUSH_FRAME_POINTER - movq PCPU(CURPCB),%r9 - movq $copy_fault,PCB_ONFAULT(%r9) + movq PCPU(CURPCB),%r11 + movq $copy_fault,PCB_ONFAULT(%r11) /* * make sure address is valid @@ -683,37 +680,20 @@ END(copyout_smap_erms) cmpq %rcx,%rax ja copy_fault + xorl %eax,%eax + movq %rdi,%r8 movq %rsi,%rdi movq %r8,%rsi movq %rdx,%rcx - xorl %eax,%eax - SMAP_DISABLE \smap -.if \erms == 0 - cmpq $15,%rcx - jbe 1f - shrq $3,%rcx /* copy longword-wise */ - rep - movsq - movb %dl,%cl - andb $7,%cl /* copy remaining bytes */ - jne 1f - SMAP_ENABLE \smap - movq %rax,PCB_ONFAULT(%r9) - POP_FRAME_POINTER - ret - ALIGN_TEXT -1: +.if \smap == 1 + MEMMOVE erms=\erms overlap=0 begin=COPYINOUT_BEGIN end=COPYINOUT_SMAP_END +.else + MEMMOVE erms=\erms overlap=0 begin=COPYINOUT_BEGIN end=COPYINOUT_END .endif - rep - movsb - - SMAP_ENABLE \smap - movq %rax,PCB_ONFAULT(%r9) - POP_FRAME_POINTER - ret + /* NOTREACHED */ .endm ENTRY(copyin_nosmap_std) @@ -735,7 +715,7 @@ END(copyin_smap_erms) ALIGN_TEXT /* Trap entry clears PSL.AC */ copy_fault: - movq $0,PCB_ONFAULT(%r9) + movq $0,PCB_ONFAULT(%r11) movl $EFAULT,%eax POP_FRAME_POINTER ret -- cgit v1.2.3