From patchwork Fri Sep 18 16:10:47 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Machado X-Patchwork-Id: 8785 Received: (qmail 65830 invoked by alias); 18 Sep 2015 16:11:01 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 65820 invoked by uid 89); 18 Sep 2015 16:11:01 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.4 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_LOW, SPF_PASS autolearn=ham version=3.3.2 X-HELO: relay1.mentorg.com Received: from relay1.mentorg.com (HELO relay1.mentorg.com) (192.94.38.131) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 18 Sep 2015 16:11:00 +0000 Received: from svr-orw-fem-05.mgc.mentorg.com ([147.34.97.43]) by relay1.mentorg.com with esmtp id 1ZcyFU-00009w-J4 from Luis_Gustavo@mentor.com ; Fri, 18 Sep 2015 09:10:56 -0700 Received: from opsys.world.mentorg.com (147.34.91.1) by svr-orw-fem-05.mgc.mentorg.com (147.34.97.43) with Microsoft SMTP Server id 14.3.224.2; Fri, 18 Sep 2015 09:10:55 -0700 From: Luis Machado To: CC: Subject: [PATCH] Expect SI_KERNEL si_code for a MIPS software breakpoint trap Date: Fri, 18 Sep 2015 13:10:47 -0300 Message-ID: <1442592647-3051-1-git-send-email-lgustavo@codesourcery.com> MIME-Version: 1.0 X-IsSubscribed: yes While doing some MIPS/Linux tests, i've found a number of threading tests failing due to spurious SIGTRAP's. Turns out those spurious SIGTRAP's were actually software breakpoint hits that were supposed to be handled silently by GDB/GDBserver, returning a swbreak event. gdb.threads/continue-pending-status.exp is one of the testcases that show this behavior. --- Breakpoint 1, main () at gdb.threads/continue-pending-status.c:44^M 44 pthread_barrier_init (&barrier, NULL, NUM_THREADS);^M (gdb) b continue-pending-status.c:36^M Breakpoint 2 at 0x400a04: file gdb.threads/continue-pending-status.c, line 36.^M (gdb) PASS: gdb.threads/continue-pending-status.exp: attempt 0: set break in tight loop continue^M Continuing.^M [New Thread 5850]^M [New Thread 5851]^M [Switching to Thread 5850]^M ^M Breakpoint 2, thread_function (arg=0x0) at gdb.threads/continue-pending-status.c:36^M 36 while (1); /* break here */^M (gdb) PASS: gdb.threads/continue-pending-status.exp: attempt 0: continue to tight loop print /x $_thread^M $1 = 0x2^M (gdb) PASS: gdb.threads/continue-pending-status.exp: attempt 0: get thread number thread 3^M [Switching to thread 3 (Thread 5851)]^M 36 while (1); /* break here */^M (gdb) PASS: gdb.threads/continue-pending-status.exp: attempt 0: switch to non-event thread delete breakpoints^M Delete all breakpoints? (y or n) y^M (gdb) info breakpoints^M No breakpoints or watchpoints.^M (gdb) continue^M Continuing.^M ^M Program received signal SIGTRAP, Trace/breakpoint trap.^M <<<< This SIGTRAP was a pending breakpoint event that wasn't supposed to cause <<<< a stop, but gdbserver did not figure out this was a breakpoint hit. PASS: gdb.threads/continue-pending-status.exp: attempt 0: continue for ctrl-c thread_function (arg=0x0) at gdb.threads/continue-pending-status.c:36^M 36 while (1); /* break here */^M (gdb) FAIL: gdb.threads/continue-pending-status.exp: attempt 0: caught interrupt -- I tracked this down to the lack of a proper definition of what MIPS' kernel returns in the si_code for a software breakpoint trap. Though i did not find documentation about this, tests showed that we should check for SI_KERNEL, just like i386. I've cc-ed Maciej, just to be sure this is indeed correct. With the following patch i have cleaner results for thread tests on MIPS/Linux. Regression-tested on a few MIPS boards. OK? gdb/ChangeLog: 2015-09-18 Luis Machado * nat/linux-ptrace.h: Check for SI_KERNEL si_code for MIPS. --- gdb/nat/linux-ptrace.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/gdb/nat/linux-ptrace.h b/gdb/nat/linux-ptrace.h index 1be38fe..09c8bc5 100644 --- a/gdb/nat/linux-ptrace.h +++ b/gdb/nat/linux-ptrace.h @@ -142,7 +142,7 @@ struct buffer; The generic Linux target code should use GDB_ARCH_IS_TRAP_BRKPT instead of TRAP_BRKPT to abstract out these peculiarities. */ -#if defined __i386__ || defined __x86_64__ +#if defined __i386__ || defined __x86_64__ || defined __mips__ # define GDB_ARCH_IS_TRAP_BRKPT(X) ((X) == SI_KERNEL) #elif defined __powerpc__ # define GDB_ARCH_IS_TRAP_BRKPT(X) ((X) == SI_KERNEL || (X) == TRAP_BRKPT)