From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8987 invoked by alias); 24 Jul 2014 14:09:44 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 8965 invoked by uid 89); 24 Jul 2014 14:09:43 -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,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS 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; Thu, 24 Jul 2014 14:09:42 +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 s6OE9UCW020831 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 24 Jul 2014 10:09:30 -0400 Received: from blade.nx (ovpn-116-66.ams2.redhat.com [10.36.116.66]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s6OE9TvW020825; Thu, 24 Jul 2014 10:09:30 -0400 Received: from blade.nx (localhost [127.0.0.1]) by blade.nx (Postfix) with ESMTP id DD3432640CA; Thu, 24 Jul 2014 15:09:28 +0100 (BST) From: Gary Benson To: gdb-patches@sourceware.org Cc: Doug Evans , Pedro Alves , Tom Tromey Subject: [PATCH 2/3 v5] Remove some GDBSERVER checks from linux-ptrace Date: Thu, 24 Jul 2014 14:13:00 -0000 Message-Id: <1406210968-11179-1-git-send-email-gbenson@redhat.com> In-Reply-To: <53D108F0.9060100@redhat.com> References: <53D108F0.9060100@redhat.com> X-IsSubscribed: yes X-SW-Source: 2014-07/txt/msg00634.txt.bz2 Pedro Alves wrote: > On 07/24/2014 01:51 PM, Gary Benson wrote: > > /* We got the PID from the grandchild, which means fork > > tracing is supported. */ > > -#ifdef GDBSERVER > > - /* Do not enable all the options for now since gdbserver does not > > - properly support them. This restriction will be lifted when > > - gdbserver is augmented to support them. */ > > - current_ptrace_options |= PTRACE_O_TRACECLONE; > > -#else > > - current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK > > - | PTRACE_O_TRACECLONE | PTRACE_O_TRACEEXEC; > > - > > - /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to > > - support read-only process state. */ > > -#endif > > + current_ptrace_options |= PTRACE_O_TRACECLONE | > > + (additional_flags & ~(PTRACE_O_TRACESYSGOOD > > + | PTRACE_O_TRACEVFORKDONE)); > > This isn't right. That enables e.g., PTRACE_O_TRACEEXIT, for > example, and possibly invalid flags even. > > Please reverse that and spell out the flags we want here explicitly, > like: > > current_ptrace_options |= PTRACE_O_TRACECLONE; > current_ptrace_options |= (additional_flags & (PTRACE_O_TRACEFORK > | PTRACE_O_TRACEVFORK > | PTRACE_O_TRACEEXEC)); Like this? gdb/ 2014-07-24 Tom Tromey Gary Benson * nat/linux-ptrace.c (additional_flags): New global. (linux_test_for_tracesysgood, linux_test_for_tracefork): Use additional_flags; don't check GDBSERVER. (linux_ptrace_set_additional_flags): New function. * nat/linux-ptrace.h (linux_ptrace_set_additional_flags): Declare. * linux-nat.c (_initialize_linux_nat): Call linux_ptrace_set_additional_flags. --- gdb/ChangeLog | 12 ++++++++++ gdb/linux-nat.c | 8 ++++++ gdb/nat/linux-ptrace.c | 56 ++++++++++++++++++++++++++--------------------- gdb/nat/linux-ptrace.h | 1 + 4 files changed, 52 insertions(+), 25 deletions(-) diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index b50a88e..7db1b3d 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -5033,6 +5033,14 @@ Enables printf debugging output."), sigdelset (&suspend_mask, SIGCHLD); sigemptyset (&blocked_mask); + + /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to + support read-only process state. */ + linux_ptrace_set_additional_flags (PTRACE_O_TRACESYSGOOD + | PTRACE_O_TRACEVFORKDONE + | PTRACE_O_TRACEVFORK + | PTRACE_O_TRACEFORK + | PTRACE_O_TRACEEXEC); } diff --git a/gdb/nat/linux-ptrace.c b/gdb/nat/linux-ptrace.c index 3ad2113..24b02b9 100644 --- a/gdb/nat/linux-ptrace.c +++ b/gdb/nat/linux-ptrace.c @@ -37,6 +37,10 @@ there are no supported features. */ static int current_ptrace_options = -1; +/* Additional flags to test. */ + +static int additional_flags; + /* Find all possible reasons we could fail to attach PID and append these as strings to the already initialized BUFFER. '\0' termination of BUFFER must be done by the caller. */ @@ -359,16 +363,16 @@ linux_check_ptrace_features (void) static void linux_test_for_tracesysgood (int child_pid) { -#ifdef GDBSERVER - /* gdbserver does not support PTRACE_O_TRACESYSGOOD. */ -#else int ret; + if ((additional_flags & PTRACE_O_TRACESYSGOOD) == 0) + return; + ret = ptrace (PTRACE_SETOPTIONS, child_pid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) PTRACE_O_TRACESYSGOOD); + if (ret == 0) current_ptrace_options |= PTRACE_O_TRACESYSGOOD; -#endif } /* Determine if PTRACE_O_TRACEFORK can be used to follow fork @@ -388,16 +392,15 @@ linux_test_for_tracefork (int child_pid) if (ret != 0) return; -#ifdef GDBSERVER - /* gdbserver does not support PTRACE_O_TRACEVFORKDONE yet. */ -#else - /* Check if the target supports PTRACE_O_TRACEVFORKDONE. */ - ret = ptrace (PTRACE_SETOPTIONS, child_pid, (PTRACE_TYPE_ARG3) 0, - (PTRACE_TYPE_ARG4) (PTRACE_O_TRACEFORK - | PTRACE_O_TRACEVFORKDONE)); - if (ret == 0) - current_ptrace_options |= PTRACE_O_TRACEVFORKDONE; -#endif + if ((additional_flags & PTRACE_O_TRACEVFORKDONE) != 0) + { + /* Check if the target supports PTRACE_O_TRACEVFORKDONE. */ + ret = ptrace (PTRACE_SETOPTIONS, child_pid, (PTRACE_TYPE_ARG3) 0, + (PTRACE_TYPE_ARG4) (PTRACE_O_TRACEFORK + | PTRACE_O_TRACEVFORKDONE)); + if (ret == 0) + current_ptrace_options |= PTRACE_O_TRACEVFORKDONE; + } /* Setting PTRACE_O_TRACEFORK did not cause an error, however we don't know for sure that the feature is available; old @@ -433,18 +436,10 @@ linux_test_for_tracefork (int child_pid) /* We got the PID from the grandchild, which means fork tracing is supported. */ -#ifdef GDBSERVER - /* Do not enable all the options for now since gdbserver does not - properly support them. This restriction will be lifted when - gdbserver is augmented to support them. */ current_ptrace_options |= PTRACE_O_TRACECLONE; -#else - current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK - | PTRACE_O_TRACECLONE | PTRACE_O_TRACEEXEC; - - /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to - support read-only process state. */ -#endif + current_ptrace_options |= (additional_flags & (PTRACE_O_TRACEFORK + | PTRACE_O_TRACEVFORK + | PTRACE_O_TRACEEXEC)); /* Do some cleanup and kill the grandchild. */ my_waitpid (second_pid, &second_status, 0); @@ -551,3 +546,14 @@ linux_ptrace_init_warnings (void) linux_ptrace_test_ret_to_nx (); } + +/* Set additional ptrace flags to use. Some such flags may be checked + by the implementation above. This function must be called before + any other function in this file; otherwise the flags may not take + effect appropriately. */ + +void +linux_ptrace_set_additional_flags (int flags) +{ + additional_flags = flags; +} diff --git a/gdb/nat/linux-ptrace.h b/gdb/nat/linux-ptrace.h index cffb5ce..41b3198 100644 --- a/gdb/nat/linux-ptrace.h +++ b/gdb/nat/linux-ptrace.h @@ -91,5 +91,6 @@ extern int linux_supports_tracefork (void); extern int linux_supports_traceclone (void); extern int linux_supports_tracevforkdone (void); extern int linux_supports_tracesysgood (void); +extern void linux_ptrace_set_additional_flags (int); #endif /* COMMON_LINUX_PTRACE_H */ -- 1.7.1