diff options
Diffstat (limited to 'crypto/bn/asm/x86_64-mont.pl')
| -rwxr-xr-x | crypto/bn/asm/x86_64-mont.pl | 40 |
1 files changed, 37 insertions, 3 deletions
diff --git a/crypto/bn/asm/x86_64-mont.pl b/crypto/bn/asm/x86_64-mont.pl index 17fb94c84c9f..c8ae019da1b9 100755 --- a/crypto/bn/asm/x86_64-mont.pl +++ b/crypto/bn/asm/x86_64-mont.pl @@ -91,6 +91,20 @@ bn_mul_mont: mov %r11,8(%rsp,$num,8) # tp[num+1]=%rsp .Lmul_body: + # Some OSes, *cough*-dows, insist on stack being "wired" to + # physical memory in strictly sequential manner, i.e. if stack + # allocation spans two pages, then reference to farmost one can + # be punishable by SEGV. But page walking can do good even on + # other OSes, because it guarantees that villain thread hits + # the guard page before it can make damage to innocent one... + sub %rsp,%r11 + and \$-4096,%r11 +.Lmul_page_walk: + mov (%rsp,%r11),%r10 + sub \$4096,%r11 + .byte 0x66,0x2e # predict non-taken + jnc .Lmul_page_walk + mov $bp,%r12 # reassign $bp ___ $bp="%r12"; @@ -296,6 +310,14 @@ bn_mul4x_mont: mov %r11,8(%rsp,$num,8) # tp[num+1]=%rsp .Lmul4x_body: + sub %rsp,%r11 + and \$-4096,%r11 +.Lmul4x_page_walk: + mov (%rsp,%r11),%r10 + sub \$4096,%r11 + .byte 0x2e # predict non-taken + jnc .Lmul4x_page_walk + mov $rp,16(%rsp,$num,8) # tp[num+2]=$rp mov %rdx,%r12 # reassign $bp ___ @@ -707,6 +729,7 @@ $code.=<<___; .align 16 bn_sqr4x_mont: .Lsqr4x_enter: + mov %rsp,%rax push %rbx push %rbp push %r12 @@ -715,12 +738,23 @@ bn_sqr4x_mont: push %r15 shl \$3,${num}d # convert $num to bytes - xor %r10,%r10 mov %rsp,%r11 # put aside %rsp - sub $num,%r10 # -$num + neg $num # -$num mov ($n0),$n0 # *n0 - lea -72(%rsp,%r10,2),%rsp # alloca(frame+2*$num) + lea -72(%rsp,$num,2),%rsp # alloca(frame+2*$num) and \$-1024,%rsp # minimize TLB usage + + sub %rsp,%r11 + and \$-4096,%r11 +.Lsqr4x_page_walk: + mov (%rsp,%r11),%r10 + sub \$4096,%r11 + .byte 0x2e # predict non-taken + jnc .Lsqr4x_page_walk + + mov $num,%r10 + neg $num # restore $num + lea -48(%rax),%r11 # restore saved %rsp ############################################################## # Stack layout # |