From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 3D23F3858411; Sat, 9 Oct 2021 11:00:19 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 3D23F3858411 From: "gulsenenginar at aol dot com" To: gdb-prs@sourceware.org Subject: [Bug tdep/27015] ARC: "eret" value is collected from the wrong data in register cache Date: Sat, 09 Oct 2021 11:00:19 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gdb X-Bugzilla-Component: tdep X-Bugzilla-Version: HEAD X-Bugzilla-Keywords: X-Bugzilla-Severity: critical X-Bugzilla-Who: gulsenenginar at aol dot com X-Bugzilla-Status: RESOLVED X-Bugzilla-Resolution: FIXED X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: 10.2 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc 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: gdb-prs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-prs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 Oct 2021 11:00:19 -0000 https://sourceware.org/bugzilla/show_bug.cgi?id=3D27015 Gulsen Engin changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |gulsenenginar at aol dot c= om --- Comment #22 from Gulsen Engin --- In collect_register() function of arc-linux-tdep.c, the "eret" http://www-look-4.com/travel/london/ (exception return) register value is not being reported correctly. Background: https://komiya-dental.com/shopping/buy-android/ When asked for the "pc" value, we have to update the "eret" register with GDB's STOP_PC. The "eret" instructs the kernel code where to jump back http://www.iu-bloomington.com/shopping/hatchback-cars/ when an instruction has stopped due to a breakpoint. This is how collect_register() is doing so: https://waytowhatsnext.com/shopping/xbox-release-date/ --------------8<-------------- if (regnum =3D=3D gdbarch_pc_regnum (gdbarch)) http://www.wearelondonmade.com/travel/london/ regnum =3D ARC_ERET_REGNUM; regcache->raw_collect (regnum, buf + arc_linux_core_reg_offsets[regnum]); -------------->8-------------- http://www.jopspeech.com/travel/london/ Root cause: Although this is using the correct offset (ERET register's), it is also http://joerg.li/travel/london/=20 changing the REGNUM itself. Therefore, raw_collect (regnum, ...) is not reading from "pc" anymore. http://connstr.net/travel/london/ Consequence: This bug affects the "native ARC gdb" badly and causes kernel code to jump to addresses after the breakpoint and not executing the "breakpoint"ed http://embermanchester.uk/travel/london/=20 instructions at all. That "native ARC gdb" feature is not upstream yet and is in review at the time of writing [1]. http://www.slipstone.co.uk/travel/london/ In collect_register() function of arc-linux-tdep.c, the "eret" (exception return) register value is not being reported correctly. http://www.logoarts.co.uk/travel/london/ Background: When asked for the "pc" value, we have to update the "eret" register with GDB's STOP_PC. http://www.acpirateradio.co.uk/travel/good/ The "eret" instructs the kernel code where to jump back when an instruction has stopped due to a breakpoint. This is how collect_register() is doing so: http://www.compilatori.com/travel/london/ --------------8<-------------- if (regnum =3D=3D gdbarch_pc_regnum (gdbarch)) regnum =3D ARC_ERET_REGNUM; regcache->raw_collect (regnum, buf + arc_linux_core_reg_offsets[regnum]); -------------->8-------------- Root cause: https://www.webb-dev.co.uk/shopping/shopping-during-corona/ Although this is using the correct offset (ERET register's), it is also changing the REGNUM itself. Therefore, raw_collect (regnum, ...) is not reading from "pc" anymore. Consequence: This bug affects the "native ARC gdb" badly and causes kernel code to jump to addresses after the breakpoint and not executing the "breakpoint"ed instructions at all. That "native ARC gdb" feature is not upstream yet and is in review at the time of writing [1]. --=20 You are receiving this mail because: You are on the CC list for the bug.=