From: Peter Maydell Date: Fri, 14 Nov 2025 17:54:17 +0000 (+0000) Subject: target/i386: Mark VPERMILPS as not valid with prefix 0 X-Git-Tag: v10.2.0-rc2~15^2~7 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ebd9ea2947d88f237e20333fe547ca8817d0b0ee;p=thirdparty%2Fqemu.git target/i386: Mark VPERMILPS as not valid with prefix 0 There are a small set of binary SSE insns which have no MMX equivalent, which we create the gen functions for with the BINARY_INT_SSE() macro. This forwards to gen_binary_int_sse() with a NULL pointer for 'mmx'. For almost all of these insns we correctly mark them in the decode table as not permitting a zero prefix byte; however we got this wrong for VPERMILPS, with the result that a bogus instruction would get through the decode checks and end up in gen_binary_int_sse() trying to call a NULL pointer. Correct the decode table entry for VPERMILPS so that we get the expected #UD exception. In the x86 SDM, table A-4 "Three-byte Opcode Map: 08H-FFH (First Two Bytes are 0F 38H)" confirms that there is no pfx 0 version of VPERMILPS. Cc: qemu-stable@nongnu.org Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3199 Signed-off-by: Peter Maydell Link: https://lore.kernel.org/r/20251114175417.2794804-1-peter.maydell@linaro.org Signed-off-by: Paolo Bonzini --- diff --git a/target/i386/tcg/decode-new.c.inc b/target/i386/tcg/decode-new.c.inc index f4192f1006..805cfd08e8 100644 --- a/target/i386/tcg/decode-new.c.inc +++ b/target/i386/tcg/decode-new.c.inc @@ -643,7 +643,7 @@ static const X86OpEntry opcodes_0F38_00toEF[240] = { [0x0a] = X86_OP_ENTRY3(PSIGND, V,x, H,x, W,x, vex4 cpuid(SSSE3) mmx avx2_256 p_00_66), [0x0b] = X86_OP_ENTRY3(PMULHRSW, V,x, H,x, W,x, vex4 cpuid(SSSE3) mmx avx2_256 p_00_66), /* Listed incorrectly as type 4 */ - [0x0c] = X86_OP_ENTRY3(VPERMILPS, V,x, H,x, W,x, vex6 chk(W0) cpuid(AVX) p_00_66), + [0x0c] = X86_OP_ENTRY3(VPERMILPS, V,x, H,x, W,x, vex6 chk(W0) cpuid(AVX) p_66), [0x0d] = X86_OP_ENTRY3(VPERMILPD, V,x, H,x, W,x, vex6 chk(W0) cpuid(AVX) p_66), [0x0e] = X86_OP_ENTRY3(VTESTPS, None,None, V,x, W,x, vex6 chk(W0) cpuid(AVX) p_66), [0x0f] = X86_OP_ENTRY3(VTESTPD, None,None, V,x, W,x, vex6 chk(W0) cpuid(AVX) p_66),