Mikhail Maltsev [Sat, 28 Nov 2015 16:59:46 +0000 (16:59 +0000)]
Fix several crashes of C++ demangler on fuzzed input.
libiberty/
* cp-demangle.c (d_dump): Fix syntax error.
(d_identifier): Adjust type of len to match d_source_name.
(d_expression_1): Fix out-of-bounds access. Check code variable for
NULL before dereferencing it.
(d_find_pack): Do not recurse for FIXED_TYPE, DEFAULT_ARG and NUMBER.
(d_print_comp_inner): Add NULL pointer check.
* cp-demangle.h (d_peek_next_char): Define as inline function when
CHECK_DEMANGLER is defined.
(d_advance): Likewise.
* testsuite/demangle-expected: Add new testcases.
Markus Metzger [Thu, 19 Nov 2015 13:33:41 +0000 (14:33 +0100)]
btrace: diagnose "record btrace pt" without libipt
If GDB has been configured without libipt support, i.e. HAVE_LIBIPT is
undefined, and is running on a system that supports Intel(R) Processor Trace,
GDB will run into an internal error when trying to decode the trace.
(gdb) record btrace
(gdb) s
usage (name=0x7fffffffe954 "fib-64")
at src/fib.c:12
12 fprintf(stderr, "usage: %s <num>\n", name);
(gdb) info record
Active record target: record-btrace
Recording format: Intel(R) Processor Trace.
Buffer size: 16kB.
gdb/btrace.c:971: internal-error: Unexpected branch trace format.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
This requires a system with Linux kernel 4.1 or later running on a 5th
Generation Intel Core processor or later.
The issue is documented as PR 19297.
When trying to enable branch tracing, in addition to checking the target
support for the requested branch tracing format, also check whether GDB
supports. it.
gdb/
* btrace.c (btrace_enable): Check whether HAVE_LIBIPT is defined.
This is already how the parent is reported in the vfork/fork events,
and is actually what the fix made gdbserver do. Following the
documentation change, the event would have been reported like this
instead:
Pedro Alves [Tue, 15 Sep 2015 16:45:26 +0000 (17:45 +0100)]
PR remote/18965: vforkdone stop reply should indicate parent PID
The vforkdone stop reply misses indicating the thread ID of the vfork
parent which the event relates to:
@cindex vfork events, remote reply
@item vfork
The packet indicates that @code{vfork} was called, and @var{r}
is the thread ID of the new child process. Refer to
@ref{thread-id syntax} for the format of the @var{thread-id}
field. This packet is only applicable to targets that support
vfork events.
@cindex vforkdone events, remote reply
@item vforkdone
The packet indicates that a child process created by a vfork
has either called @code{exec} or terminated, so that the
address spaces of the parent and child process are no longer
shared. The @var{r} part is ignored. This packet is only
applicable to targets that support vforkdone events.
Unfortunately, this is not just a documentation issue. GDBserver
is really not specifying the thread ID. I noticed because
in non-stop mode, gdb complains:
[Thread 6089.6089] #1 stopped.
#0 0x0000003615a011f0 in ?? ()
0x0000003615a011f0 in ?? ()
(gdb) set debug remote 1
(gdb) c
Continuing.
Sending packet: $QPassSignals:e;10;14;17;1a;1b;1c;21;24;25;2c;4c;#5f...Packet received: OK
Sending packet: $vCont;c:p17c9.17c9#88...Packet received: OK
Notification received: Stop:T05vfork:p17ce.17ce;06:40d7ffffff7f0000;07:30d7ffffff7f0000;10:e4c9eb1536000000;thread:p17c9.17c9;core:2;
Sending packet: $vStopped#55...Packet received: OK
Sending packet: $D;17ce#af...Packet received: OK
Sending packet: $vCont;c:p17c9.17c9#88...Packet received: OK
Notification received: Stop:T05vforkdone:;
No process or thread specified in stop reply: T05vforkdone:;
(gdb)
This is not non-stop-mode-specific, however. Consider e.g., that in
all-stop, you may be debugging more than one process at the same time.
You continue, and both processes vfork. So when you next get a
T05vforkdone, there's no way to tell which of the parent processes is
done with the vfork.
Tests will be added later.
Tested on x86_64 Fedora 20.
gdb/gdbserver/ChangeLog:
2015-09-15 Pedro Alves <palves@redhat.com>
PR remote/18965
* remote-utils.c (prepare_resume_reply): Merge
TARGET_WAITKIND_VFORK_DONE switch case with the
TARGET_WAITKIND_FORKED case.
gdb/doc/ChangeLog:
2015-09-15 Pedro Alves <palves@redhat.com>
PR remote/18965
* gdb.texinfo (Stop Reply Packets): Explain that vforkdone's 'r'
part indicates the thread ID of the parent process.
Gary Benson [Mon, 14 Sep 2015 10:02:06 +0000 (11:02 +0100)]
Fix build issue with nat/linux-namespaces.c
This commit fixes a build issue on systems with a prototype for setns
in their header files but no working setns is detected by configure.
gdb/ChangeLog:
PR gdb/18957
* nat/linux-namespaces.c (setns): Rename from this ...
(do_setns): ... to this. Support calling setns if it exists.
(mnsh_handle_setns): Call do_setns.