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src/gdb/gdbserver ChangeLog tracepoint.c
- From: palves at sourceware dot org
- To: gdb-cvs at sourceware dot org
- Date: Mon, 02 Sep 2013 15:15:57 +0000
- Subject: src/gdb/gdbserver ChangeLog tracepoint.c
CVSROOT: /cvs/src
Module name: src
Changes by: palves@sourceware.org 2013-09-02 15:15:57
Modified files:
gdb/gdbserver : ChangeLog tracepoint.c
Log message:
[gdbserver] Fix trace-buffer-size.exp FAILs.
I'm seeing trace-buffer-size.exp failing (with gdbserver):
(gdb) PASS: gdb.trace/trace-buffer-size.exp: tstatus check 2
show trace-buffer-size 4
Requested size of trace buffer is 4.
(gdb) PASS: gdb.trace/trace-buffer-size.exp: show trace buffer size
set trace-buffer-size -1
memory clobbered past end of allocated block
Remote connection closed
(gdb) FAIL: gdb.trace/trace-buffer-size.exp: set trace buffer size 2
set trace-buffer-size unlimited
(gdb) PASS: gdb.trace/trace-buffer-size.exp: set trace-buffer-size unlimited
That "memory clobbered past end of allocated block" is mcheck triggering.
Valgrind shows:
==23624== Invalid write of size 1
==23624== at 0x418DD8: clear_trace_buffer (tracepoint.c:1443)
==23624== by 0x418F3A: init_trace_buffer (tracepoint.c:1497)
==23624== by 0x41D95B: cmd_bigqtbuffer_size (tracepoint.c:4061)
==23624== by 0x41DEEC: handle_tracepoint_general_set (tracepoint.c:4193)
clear_trace_buffer does:
static void
clear_trace_buffer (void)
{
trace_buffer_start = trace_buffer_lo;
trace_buffer_free = trace_buffer_lo;
trace_buffer_end_free = trace_buffer_hi;
trace_buffer_wrap = trace_buffer_hi;
/* A traceframe with zeroed fields marks the end of trace data. */
((struct traceframe *) trace_buffer_free)->tpnum = 0;
((struct traceframe *) trace_buffer_free)->data_size = 0;
traceframe_read_count = traceframe_write_count = 0;
traceframes_created = 0;
}
And the tpnum+data_size fields are over 4 bytes... This fixes it by
ensuring we allocate space at least for an EOB. We have code
elsewhere that relies on the EOB being present (like e.g.,
find_traceframe), so this seems simplest.
gdb/gdbserver/
2013-09-02 Pedro Alves <palves@redhat.com>
* tracepoint.c (TRACEFRAME_EOB_MARKER_SIZE): New macro.
(init_trace_buffer): Ensure at least TRACEFRAME_EOB_MARKER_SIZE is
allocated.
(trace_buffer_alloc): Use TRACEFRAME_EOB_MARKER_SIZE.
Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/gdbserver/ChangeLog.diff?cvsroot=src&r1=1.753&r2=1.754
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/gdbserver/tracepoint.c.diff?cvsroot=src&r1=1.81&r2=1.82