diff options
| author | Jack Lloyd <[email protected]> | 2018-04-05 11:03:48 -0400 |
|---|---|---|
| committer | Jack Lloyd <[email protected]> | 2018-04-05 11:03:48 -0400 |
| commit | 6c5d9ef3c49658cbf4096e04905e3c0debb9d096 (patch) | |
| tree | 3d3ebae9a3db98907e451d6630f6dc9f8722a8f5 /src/lib/math | |
| parent | 30f1500361b899ff436610781329ba0726d07746 (diff) | |
Split up asm constructs to avoid miscompilation
The constraints were invalid as they missed the clobber of a/d
registers. This caused miscompilation when using GCC -fno-plt option.
GH #1524
Diffstat (limited to 'src/lib/math')
| -rw-r--r-- | src/lib/math/mp/mp_asmi.h | 79 |
1 files changed, 49 insertions, 30 deletions
diff --git a/src/lib/math/mp/mp_asmi.h b/src/lib/math/mp/mp_asmi.h index 0cbce3053..1b332811f 100644 --- a/src/lib/math/mp/mp_asmi.h +++ b/src/lib/math/mp/mp_asmi.h @@ -717,29 +717,37 @@ inline word word8_madd3(word z[8], const word x[8], word y, word carry) inline void word3_muladd(word* w2, word* w1, word* w0, word x, word y) { #if defined(BOTAN_MP_USE_X86_32_ASM) - asm( - ASM("mull %[y]") + word z0 = 0, z1 = 0; - ASM("addl %[x],%[w0]") - ASM("adcl %[y],%[w1]") - ASM("adcl $0,%[w2]") + asm ("mull %[y]" + : "=a"(z0),"=d"(z1) + : "a"(x), [y]"rm"(y) + : "cc"); - : [w0]"=r"(*w0), [w1]"=r"(*w1), [w2]"=r"(*w2) - : [x]"a"(x), [y]"d"(y), "0"(*w0), "1"(*w1), "2"(*w2) - : "cc"); + asm(ASM("addl %[z0],%[w0]") + ASM("adcl %[z1],%[w1]") + ASM("adcl $0,%[w2]") + + : [w0]"=r"(*w0), [w1]"=r"(*w1), [w2]"=r"(*w2) + : [z0]"r"(z0), [z1]"r"(z1), "0"(*w0), "1"(*w1), "2"(*w2) + : "cc"); #elif defined(BOTAN_MP_USE_X86_64_ASM) - asm( - ASM("mulq %[y]") + word z0 = 0, z1 = 0; - ASM("addq %[x],%[w0]") - ASM("adcq %[y],%[w1]") - ASM("adcq $0,%[w2]") + asm ("mulq %[y]" + : "=a"(z0),"=d"(z1) + : "a"(x), [y]"rm"(y) + : "cc"); - : [w0]"=r"(*w0), [w1]"=r"(*w1), [w2]"=r"(*w2) - : [x]"a"(x), [y]"d"(y), "0"(*w0), "1"(*w1), "2"(*w2) - : "cc"); + asm(ASM("addq %[z0],%[w0]") + ASM("adcq %[z1],%[w1]") + ASM("adcq $0,%[w2]") + + : [w0]"=r"(*w0), [w1]"=r"(*w1), [w2]"=r"(*w2) + : [z0]"r"(z0), [z1]"r"(z1), "0"(*w0), "1"(*w1), "2"(*w2) + : "cc"); #else word carry = *w0; @@ -792,36 +800,47 @@ inline void word3_add(word* w2, word* w1, word* w0, word x) inline void word3_muladd_2(word* w2, word* w1, word* w0, word x, word y) { #if defined(BOTAN_MP_USE_X86_32_ASM) - asm( - ASM("mull %[y]") - ASM("addl %[x],%[w0]") - ASM("adcl %[y],%[w1]") + word z0 = 0, z1 = 0; + + asm ("mull %[y]" + : "=a"(z0),"=d"(z1) + : "a"(x), [y]"rm"(y) + : "cc"); + + asm( + ASM("addl %[z0],%[w0]") + ASM("adcl %[z1],%[w1]") ASM("adcl $0,%[w2]") - ASM("addl %[x],%[w0]") - ASM("adcl %[y],%[w1]") + ASM("addl %[z0],%[w0]") + ASM("adcl %[z1],%[w1]") ASM("adcl $0,%[w2]") : [w0]"=r"(*w0), [w1]"=r"(*w1), [w2]"=r"(*w2) - : [x]"a"(x), [y]"d"(y), "0"(*w0), "1"(*w1), "2"(*w2) + : [z0]"r"(z0), [z1]"r"(z1), "0"(*w0), "1"(*w1), "2"(*w2) : "cc"); #elif defined(BOTAN_MP_USE_X86_64_ASM) - asm( - ASM("mulq %[y]") + word z0 = 0, z1 = 0; - ASM("addq %[x],%[w0]") - ASM("adcq %[y],%[w1]") + asm ("mulq %[y]" + : "=a"(z0),"=d"(z1) + : "a"(x), [y]"rm"(y) + : "cc"); + + asm( + ASM("addq %[z0],%[w0]") + ASM("adcq %[z1],%[w1]") ASM("adcq $0,%[w2]") - ASM("addq %[x],%[w0]") - ASM("adcq %[y],%[w1]") + ASM("addq %[z0],%[w0]") + ASM("adcq %[z1],%[w1]") ASM("adcq $0,%[w2]") : [w0]"=r"(*w0), [w1]"=r"(*w1), [w2]"=r"(*w2) - : [x]"a"(x), [y]"d"(y), "0"(*w0), "1"(*w1), "2"(*w2) + : [z0]"r"(z0), [z1]"r"(z1), "0"(*w0), "1"(*w1), "2"(*w2) : "cc"); #else |