Public bug reported:
The SSE comparison ops that use an 8bit immediate as a comparison type
selector throws a sigill when the immediate is oversized.
Test op that I found this on is here `66 0f c2 c0 d1 cmppd
xmm0,xmm0,0xd1`
According to the x86-64 documentation only bits [2:0] are used for these ops
(and [4:0] for the AVX variant)
Currently qemu just checks if the value is >=8 and will throw a sigill in that
case. It instead needs to mask.
I have a small patch that fixes the issue for the SSE variant.
** Affects: qemu
Importance: Undecided
Status: New
** Patch added: "Fixes the bug"
https://bugs.launchpad.net/bugs/1832422/+attachment/5270247/+files/compare_ops.diff
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https://bugs.launchpad.net/bugs/1832422
Title:
SSE CMP ops with 8bit immediate throw sigill with oversized byte
Status in QEMU:
New
Bug description:
The SSE comparison ops that use an 8bit immediate as a comparison type
selector throws a sigill when the immediate is oversized.
Test op that I found this on is here `66 0f c2 c0 d1 cmppd
xmm0,xmm0,0xd1`
According to the x86-64 documentation only bits [2:0] are used for these ops
(and [4:0] for the AVX variant)
Currently qemu just checks if the value is >=8 and will throw a sigill in
that case. It instead needs to mask.
I have a small patch that fixes the issue for the SSE variant.
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