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From: "cvs-commit at gcc dot gnu.org" <sourceware-bugzilla@sourceware.org> To: gdb-prs@sourceware.org Subject: [Bug testsuite/30132] [gdb/testsuite] FAIL: gdb.arch/amd64-disp-step-avx.exp: continue until exit at amd64-disp-step-avx Date: Fri, 17 Feb 2023 14:33:22 +0000 [thread overview] Message-ID: <bug-30132-4717-OPsuT3rUnh@http.sourceware.org/bugzilla/> (raw) In-Reply-To: <bug-30132-4717@http.sourceware.org/bugzilla/> https://sourceware.org/bugzilla/show_bug.cgi?id=30132 --- Comment #1 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Tom de Vries <vries@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ab3fdfe6e4805eff45ec4d701d0cd6511d9c3690 commit ab3fdfe6e4805eff45ec4d701d0cd6511d9c3690 Author: Tom de Vries <tdevries@suse.de> Date: Fri Feb 17 15:33:18 2023 +0100 [gdb/testsuite] Simplify gdb.arch/amd64-disp-step-avx.exp On SLE-11, with glibc 2.11.3, I run into: ... (gdb) PASS: gdb.arch/amd64-disp-step-avx.exp: vex3: \ var128 has expected value after continue^M Continuing.^M ^M Program received signal SIGSEGV, Segmentation fault.^M 0x0000000000400283 in _exit (status=0) at \ ../sysdeps/unix/sysv/linux/_exit.c:33^M 33 ../sysdeps/unix/sysv/linux/_exit.c: No such file or directory.^M (gdb) FAIL: gdb.arch/amd64-disp-step-avx.exp: \ continue until exit at amd64-disp-step-avx ... This is not related to gdb, we get the same result by just running the exec. The problem is that the test-case: - calls glibc's _exit, and - uses -nostartfiles -static, putting the burden for any necessary initialization for calling glibc's _exit on the test-case itself. So, when we get to the second insn in _exit: ... 000000000040acb0 <_exit>: 40acb0: 48 63 d7 movslq %edi,%rdx 40acb3: 64 4c 8b 14 25 00 00 mov %fs:0x0,%r10 ... no glibc-related initialization is done, and we run into the segfault. Adding this (borrowed from __libc_start_main) in _start in the .S file is sufficient to fix it: ... .rept 200 nop + call __pthread_initialize_minimal .endr ... But that already doesn't compile with say glibc 2.31, and regardless I think this sort of fix is too fragile. We could of course fix this by simply not running to exit. But ideally we'd have an exec that doesn't segfault when you just run it. Alternatively, we could hand-code an _exit syscall and bypass glibc all together. But I'd rather fix this in a way that simplifies the test-case. Taking a step back, the -nostartfiles -static was added to address that the xmm registers were not zero at main (which AFAICT is a valid thing to happen). [ The change itself silently broke the test-case, needing further fixing by commit 40310f30a51 ("gdb: make gdb.arch/amd64-disp-step-avx.exp actually test displaced stepping"). ] Instead, simplify things by reverting to the original situation: - no -nostartfiles -static compilation flags, - no _start in the .S file, - use exit instead of _exit in the .S file, and fix the original problem by setting the xmm registers to zero rather than checking that they're zero. Now that we're no longer forcing -static, add nopie to the flags to prevent compilation failure with target board unix/-fPIE/-pie. Tested on x86_64-linux. PR testsuite/30132 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30132 -- You are receiving this mail because: You are on the CC list for the bug.
next prev parent reply other threads:[~2023-02-17 14:33 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-02-17 10:59 [Bug testsuite/30132] New: " vries at gcc dot gnu.org 2023-02-17 14:33 ` cvs-commit at gcc dot gnu.org [this message] 2023-02-17 14:34 ` [Bug testsuite/30132] " vries at gcc dot gnu.org
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