From patchwork Mon Feb 9 23:20:26 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Pedro Alves X-Patchwork-Id: 4991 Received: (qmail 12284 invoked by alias); 9 Feb 2015 23:21:38 -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 12259 invoked by uid 89); 9 Feb 2015 23:21:38 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.0 required=5.0 tests=AWL, BAYES_00, SPF_HELO_PASS, SPF_PASS, T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Mon, 09 Feb 2015 23:21:37 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t19NLaEW007044 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Mon, 9 Feb 2015 18:21:36 -0500 Received: from brno.lan (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t19NKkuf026307 for ; Mon, 9 Feb 2015 18:21:35 -0500 From: Pedro Alves To: gdb-patches@sourceware.org Subject: [PATCH 16/36] x86 Linux/ptrace: fix offsetof usage in C++ mode Date: Mon, 9 Feb 2015 23:20:26 +0000 Message-Id: <1423524046-20605-17-git-send-email-palves@redhat.com> In-Reply-To: <1423524046-20605-1-git-send-email-palves@redhat.com> References: <1423524046-20605-1-git-send-email-palves@redhat.com> MIME-Version: 1.0 In C++ mode, we get: gdb/gdbserver/linux-x86-low.c: In function ‘void x86_linux_dr_set(ptid_t, int, long unsigned int)’: gdb/gdbserver/linux-x86-low.c:558:38: error: ‘regnum’ cannot appear in a constant-expression offsetof (struct user, u_debugreg[regnum]), value); ^ gdb/gdbserver/ChangeLog: 2015-02-09 Pedro Alves * linux-x86-low.c (u_debugreg_offset): New function. (x86_linux_dr_get, x86_linux_dr_set): Use it. gdb/ChangeLog: 2015-02-09 Pedro Alves * x86-linux-nat.c (u_debugreg_offset): New function. (x86_linux_dr_get, x86_linux_dr_set): Use it. --- gdb/gdbserver/linux-x86-low.c | 18 ++++++++++++++---- gdb/x86-linux-nat.c | 17 +++++++++++++---- 2 files changed, 27 insertions(+), 8 deletions(-) diff --git a/gdb/gdbserver/linux-x86-low.c b/gdb/gdbserver/linux-x86-low.c index eff2847..c70da3d 100644 --- a/gdb/gdbserver/linux-x86-low.c +++ b/gdb/gdbserver/linux-x86-low.c @@ -527,6 +527,18 @@ x86_breakpoint_at (CORE_ADDR pc) return 0; } + +/* Return the offset of REGNUM in the u_debugreg field of struct + user. */ + +static int +u_debugreg_offset (int regnum) +{ + return (offsetof (struct user, u_debugreg) + + sizeof (((struct user *) 0)->u_debugreg[0]) * regnum); +} + + /* Support for debug registers. */ static unsigned long @@ -538,8 +550,7 @@ x86_linux_dr_get (ptid_t ptid, int regnum) tid = ptid_get_lwp (ptid); errno = 0; - value = ptrace (PTRACE_PEEKUSER, tid, - offsetof (struct user, u_debugreg[regnum]), 0); + value = ptrace (PTRACE_PEEKUSER, tid, u_debugreg_offset (regnum), 0); if (errno != 0) error ("Couldn't read debug register"); @@ -554,8 +565,7 @@ x86_linux_dr_set (ptid_t ptid, int regnum, unsigned long value) tid = ptid_get_lwp (ptid); errno = 0; - ptrace (PTRACE_POKEUSER, tid, - offsetof (struct user, u_debugreg[regnum]), value); + ptrace (PTRACE_POKEUSER, tid, u_debugreg_offset (regnum), value); if (errno != 0) error ("Couldn't write debug register"); } diff --git a/gdb/x86-linux-nat.c b/gdb/x86-linux-nat.c index 9d82be2..c58c01a 100644 --- a/gdb/x86-linux-nat.c +++ b/gdb/x86-linux-nat.c @@ -51,6 +51,16 @@ struct arch_lwp_info int have_ptrace_getregset = -1; +/* Return the offset of REGNUM in the u_debugreg field of struct + user. */ + +static int +u_debugreg_offset (int regnum) +{ + return (offsetof (struct user, u_debugreg) + + sizeof (((struct user *) 0)->u_debugreg[0]) * regnum); +} + /* Support for debug registers. */ /* Get debug register REGNUM value from only the one LWP of PTID. */ @@ -65,8 +75,8 @@ x86_linux_dr_get (ptid_t ptid, int regnum) tid = ptid_get_lwp (ptid); errno = 0; - value = ptrace (PTRACE_PEEKUSER, tid, - offsetof (struct user, u_debugreg[regnum]), 0); + value = ptrace (PTRACE_PEEKUSER, tid, u_debugreg_offset (regnum), 0); + if (errno != 0) perror_with_name (_("Couldn't read debug register")); @@ -84,8 +94,7 @@ x86_linux_dr_set (ptid_t ptid, int regnum, unsigned long value) tid = ptid_get_lwp (ptid); errno = 0; - ptrace (PTRACE_POKEUSER, tid, - offsetof (struct user, u_debugreg[regnum]), value); + ptrace (PTRACE_POKEUSER, tid, u_debugreg_offset (regnum), value); if (errno != 0) perror_with_name (_("Couldn't write debug register")); }