From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id DB06239518BE; Thu, 13 Jan 2022 14:22:19 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org DB06239518BE From: "fweimer at redhat dot com" To: glibc-bugs@sourceware.org Subject: [Bug libc/28771] %ebx optimization macros are incompatible with .altmacro in Systemtap probes Date: Thu, 13 Jan 2022 14:22:19 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: glibc X-Bugzilla-Component: libc X-Bugzilla-Version: 2.35 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: fweimer at redhat dot com X-Bugzilla-Status: RESOLVED X-Bugzilla-Resolution: FIXED X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: fweimer at redhat dot com X-Bugzilla-Target-Milestone: 2.35 X-Bugzilla-Flags: security- X-Bugzilla-Changed-Fields: resolution bug_status target_milestone cc assigned_to Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: glibc-bugs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Glibc-bugs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Jan 2022 14:22:20 -0000 https://sourceware.org/bugzilla/show_bug.cgi?id=3D28771 Florian Weimer changed: What |Removed |Added ---------------------------------------------------------------------------- Resolution|--- |FIXED Status|NEW |RESOLVED Target Milestone|--- |2.35 CC| |fweimer at redhat dot com Assignee|unassigned at sourceware dot org |fweimer at redhat d= ot com --- Comment #1 from Florian Weimer --- Fixed for 2.35 via: commit a78e6a10d0b50d0ca80309775980fc99944b1727 Author: Florian Weimer Date: Thu Jan 13 14:59:29 2022 +0100 i386: Remove broken CAN_USE_REGISTER_ASM_EBP (bug 28771) The configure check for CAN_USE_REGISTER_ASM_EBP tried to compile a simple function that uses %ebp as an inline assembly operand. If compilation failed, CAN_USE_REGISTER_ASM_EBP was set 0, which eventually had these consequences: (1) %ebx was avoided as an inline assembly operand, with an assembler macro hack to avoid unnecessary register moves. (2) %ebp was avoided as an inline assembly operand, using an out-of-line syscall function for 6-argument system calls. (1) is no longer needed for any GCC version that is supported for building glibc. %ebx can be used directly as a register operand. Therefore, this commit removes the %ebx avoidance completely. This avoids the assembler macro hack, which turns out to be incompatible with the current Systemtap probe macros (which switch to .altmacro unconditionally). (2) is still needed in many build configurations. The existing configure check cannot really capture that because the simple function succeeds to compile, while the full glibc build still fails. Therefore, this commit removes the check, the CAN_USE_REGISTER_ASM_EBP macro, and uses the out-of-line syscall function for 6-argument system calls unconditionally. Reviewed-by: H.J. Lu --=20 You are receiving this mail because: You are on the CC list for the bug.=