diff options
Diffstat (limited to 'toolchain/musl/patches/030-fix-x87-stack-imbalance-in-corner-cases-of-i386-math.patch')
| -rw-r--r-- | toolchain/musl/patches/030-fix-x87-stack-imbalance-in-corner-cases-of-i386-math.patch | 179 |
1 files changed, 0 insertions, 179 deletions
diff --git a/toolchain/musl/patches/030-fix-x87-stack-imbalance-in-corner-cases-of-i386-math.patch b/toolchain/musl/patches/030-fix-x87-stack-imbalance-in-corner-cases-of-i386-math.patch deleted file mode 100644 index a709330079..0000000000 --- a/toolchain/musl/patches/030-fix-x87-stack-imbalance-in-corner-cases-of-i386-math.patch +++ /dev/null @@ -1,179 +0,0 @@ -From f3ed8bfe8a82af1870ddc8696ed4cc1d5aa6b441 Mon Sep 17 00:00:00 2001 -From: Rich Felker <dalias@aerifal.cx> -Date: Mon, 5 Aug 2019 18:41:47 -0400 -Subject: fix x87 stack imbalance in corner cases of i386 math asm - -commit 31c5fb80b9eae86f801be4f46025bc6532a554c5 introduced underflow -code paths for the i386 math asm, along with checks on the fpu status -word to skip the underflow-generation instructions if the underflow -flag was already raised. unfortunately, at least one such path, in -log1p, returned with 2 items on the x87 stack rather than just 1 item -for the return value. this is a violation of the ABI's calling -convention, and could cause subsequent floating point code to produce -NANs due to x87 stack overflow. if floating point results are used in -flow control, this can lead to runaway wrong code execution. - -rather than reviewing each "underflow already raised" code path for -correctness, remove them all. they're likely slower than just -performing the underflow code unconditionally, and significantly more -complex. - -all of this code should be ripped out and replaced by C source files -with inline asm. doing so would preclude this kind of error by having -the compiler perform all x87 stack register allocation and stack -manipulation, and would produce comparable or better code. however -such a change is a much larger project. ---- - src/math/i386/asin.s | 10 ++-------- - src/math/i386/atan.s | 7 ++----- - src/math/i386/atan2.s | 5 +---- - src/math/i386/atan2f.s | 5 +---- - src/math/i386/atanf.s | 7 ++----- - src/math/i386/exp.s | 10 ++-------- - src/math/i386/log1p.s | 7 ++----- - src/math/i386/log1pf.s | 7 ++----- - 8 files changed, 14 insertions(+), 44 deletions(-) - ---- a/src/math/i386/asin.s -+++ b/src/math/i386/asin.s -@@ -7,13 +7,10 @@ asinf: - cmp $0x01000000,%eax - jae 1f - # subnormal x, return x with underflow -- fnstsw %ax -- and $16,%ax -- jnz 2f - fld %st(0) - fmul %st(1) - fstps 4(%esp) --2: ret -+ ret - - .global asinl - .type asinl,@function -@@ -30,11 +27,8 @@ asin: - cmp $0x00200000,%eax - jae 1f - # subnormal x, return x with underflow -- fnstsw %ax -- and $16,%ax -- jnz 2f - fsts 4(%esp) --2: ret -+ ret - 1: fld %st(0) - fld1 - fsub %st(0),%st(1) ---- a/src/math/i386/atan.s -+++ b/src/math/i386/atan.s -@@ -10,8 +10,5 @@ atan: - fpatan - ret - # subnormal x, return x with underflow --1: fnstsw %ax -- and $16,%ax -- jnz 2f -- fsts 4(%esp) --2: ret -+1: fsts 4(%esp) -+ ret ---- a/src/math/i386/atan2.s -+++ b/src/math/i386/atan2.s -@@ -10,8 +10,5 @@ atan2: - cmp $0x00200000,%eax - jae 1f - # subnormal x, return x with underflow -- fnstsw %ax -- and $16,%ax -- jnz 1f - fsts 4(%esp) --1: ret -+ ret ---- a/src/math/i386/atan2f.s -+++ b/src/math/i386/atan2f.s -@@ -10,10 +10,7 @@ atan2f: - cmp $0x01000000,%eax - jae 1f - # subnormal x, return x with underflow -- fnstsw %ax -- and $16,%ax -- jnz 1f - fld %st(0) - fmul %st(1) - fstps 4(%esp) --1: ret -+ ret ---- a/src/math/i386/atanf.s -+++ b/src/math/i386/atanf.s -@@ -10,10 +10,7 @@ atanf: - fpatan - ret - # subnormal x, return x with underflow --1: fnstsw %ax -- and $16,%ax -- jnz 2f -- fld %st(0) -+1: fld %st(0) - fmul %st(1) - fstps 4(%esp) --2: ret -+ ret ---- a/src/math/i386/exp.s -+++ b/src/math/i386/exp.s -@@ -7,13 +7,10 @@ expm1f: - cmp $0x01000000,%eax - jae 1f - # subnormal x, return x with underflow -- fnstsw %ax -- and $16,%ax -- jnz 2f - fld %st(0) - fmul %st(1) - fstps 4(%esp) --2: ret -+ ret - - .global expm1l - .type expm1l,@function -@@ -30,11 +27,8 @@ expm1: - cmp $0x00200000,%eax - jae 1f - # subnormal x, return x with underflow -- fnstsw %ax -- and $16,%ax -- jnz 2f - fsts 4(%esp) --2: ret -+ ret - 1: fldl2e - fmulp - mov $0xc2820000,%eax ---- a/src/math/i386/log1p.s -+++ b/src/math/i386/log1p.s -@@ -16,9 +16,6 @@ log1p: - fyl2x - ret - # subnormal x, return x with underflow --2: fnstsw %ax -- and $16,%ax -- jnz 1f -- fsts 4(%esp) -+2: fsts 4(%esp) - fstp %st(1) --1: ret -+ ret ---- a/src/math/i386/log1pf.s -+++ b/src/math/i386/log1pf.s -@@ -16,10 +16,7 @@ log1pf: - fyl2x - ret - # subnormal x, return x with underflow --2: fnstsw %ax -- and $16,%ax -- jnz 1f -- fxch -+2: fxch - fmul %st(1) - fstps 4(%esp) --1: ret -+ ret |