From 868883583e7520ff1bd99fcb224d2b33a990edff Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Sat, 23 Mar 2024 16:17:36 +0000 Subject: gdb/arch: assert that X86_XSTATE_MPX is not set for x32 While rebasing this series[1] past this commit: commit 4bb20a6244b7091a9a7a2ae35dfbd7e8db27550a Date: Wed Mar 20 04:13:18 2024 -0700 gdbserver: Clear X86_XSTATE_MPX bits in xcr0 on x32 I worried that there could be other paths that might result in an xcr0 value which has X86_XSTATE_MPX set in x32 mode. As everyone eventually calls amd64_create_target_description to build their target description, I figured we could assert in here that if X86_XSTATE_MPX is set then we should not be an x32 target, this will uncover any other bugs in this area. I'm not currently able to build/run any x32 binaries, so I have no way to test this, but the author of commit 4bb20a6244b7091 did test this series with that assert in place and didn't see any problems. [1] https://inbox.sourceware.org/gdb-patches/cover.1714143669.git.aburgess@redhat.com Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31511 Approved-By: Felix Willgerodt --- gdb/arch/amd64.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/gdb/arch/amd64.c b/gdb/arch/amd64.c index cb9683c..94d55d7 100644 --- a/gdb/arch/amd64.c +++ b/gdb/arch/amd64.c @@ -65,8 +65,12 @@ amd64_create_target_description (uint64_t xcr0, bool is_x32, bool is_linux, if (xcr0 & X86_XSTATE_AVX) regnum = create_feature_i386_64bit_avx (tdesc.get (), regnum); - if ((xcr0 & X86_XSTATE_MPX) && !is_x32) - regnum = create_feature_i386_64bit_mpx (tdesc.get (), regnum); + if (xcr0 & X86_XSTATE_MPX) + { + /* MPX is not available on x32. */ + gdb_assert (!is_x32); + regnum = create_feature_i386_64bit_mpx (tdesc.get (), regnum); + } if (xcr0 & X86_XSTATE_AVX512) regnum = create_feature_i386_64bit_avx512 (tdesc.get (), regnum); -- cgit v1.1