From 62c222b6d9fcce8adf65f48fca2e528f777afeeb Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Thu, 22 Mar 2018 00:26:37 -0400 Subject: [PATCH] Make parse_static_tracepoint_marker_definition work with multiple static tracepoint definitions Since I modify the parse_static_tracepoint_marker_definition function in the next patch, I wanted to write a unit test for it. Doing so showed that it doesn't handle multiple consecutive static tracepoint definitions separated by commas. However, the RSP documentation [1] states that servers may return multiple definitions, like: 1234:6d61726b657231:6578747261207374756666,abba:6d61726b657232: The problem is that the function uses strlen to compute the length of the last field (the extra field). If there are additional definitions in addition to the one we are currently parsing, the returned length will include those definitions, and we'll try to hex-decode past the extra field. This patch changes parse_static_tracepoint_marker_definition to consider the case where the current definition is followed by a comma and more definitions. It also adds the unit test that found the issue in the first place. I don't think this causes any backwards compatibility issues, because the previous code only handled single static tracepoint definitions, and the new code handles that correctly. gdb/ChangeLog: * tracepoint.c (parse_static_tracepoint_marker_definition): Consider case where the definition is followed by more definitions. * Makefile.in (SUBDIR_UNITTESTS_SRCS): Add tracepoint-selftests.c. * unittests/tracepoint-selftests.c: New. [1] https://sourceware.org/gdb/onlinedocs/gdb/Tracepoint-Packets.html#qTfSTM --- gdb/ChangeLog | 9 ++++ gdb/Makefile.in | 1 + gdb/tracepoint.c | 14 ++++-- gdb/unittests/tracepoint-selftests.c | 70 ++++++++++++++++++++++++++++ 4 files changed, 91 insertions(+), 3 deletions(-) create mode 100644 gdb/unittests/tracepoint-selftests.c diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 1ed88247af9..6af571c509a 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,12 @@ +2018-03-22 Simon Marchi + + * tracepoint.c (parse_static_tracepoint_marker_definition): + Consider case where the definition is followed by more + definitions. + * Makefile.in (SUBDIR_UNITTESTS_SRCS): Add + tracepoint-selftests.c. + * unittests/tracepoint-selftests.c: New. + 2018-03-21 Pedro Franco de Carvalho * MAINTAINERS (Write After Approval): Add Pedro Franco de diff --git a/gdb/Makefile.in b/gdb/Makefile.in index 4dd9286d283..b1ba00583f9 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -430,6 +430,7 @@ SUBDIR_UNITTESTS_SRCS = \ unittests/scoped_fd-selftests.c \ unittests/scoped_mmap-selftests.c \ unittests/scoped_restore-selftests.c \ + unittests/tracepoint-selftests.c \ unittests/unpack-selftests.c \ unittests/utils-selftests.c \ unittests/xml-utils-selftests.c diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c index 30fe2069736..8e779bcba97 100644 --- a/gdb/tracepoint.c +++ b/gdb/tracepoint.c @@ -3720,12 +3720,20 @@ parse_static_tracepoint_marker_definition (const char *line, const char **pp, p += 2 * end; p++; /* skip a colon */ - marker->extra = (char *) xmalloc (strlen (p) + 1); - end = hex2bin (p, (gdb_byte *) marker->extra, strlen (p) / 2); + /* This definition may be followed by another one, separated by a comma. */ + int hex_len; + endp = strchr (p, ','); + if (endp != nullptr) + hex_len = endp - p; + else + hex_len = strlen (p); + + marker->extra = (char *) xmalloc (hex_len / 2 + 1); + end = hex2bin (p, (gdb_byte *) marker->extra, hex_len / 2); marker->extra[end] = '\0'; if (pp) - *pp = p; + *pp = p + hex_len; } /* Release a static tracepoint marker's contents. Note that the diff --git a/gdb/unittests/tracepoint-selftests.c b/gdb/unittests/tracepoint-selftests.c new file mode 100644 index 00000000000..21ca3d09149 --- /dev/null +++ b/gdb/unittests/tracepoint-selftests.c @@ -0,0 +1,70 @@ +/* Self tests for tracepoint-related code for GDB, the GNU debugger. + + Copyright (C) 2018 Free Software Foundation, Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#include "defs.h" +#include "selftest.h" +#include "tracepoint.h" + +namespace selftests { +namespace tracepoint_tests { + +static void +test_parse_static_tracepoint_marker_definition () +{ + static_tracepoint_marker marker; + const char def[] = ("1234:6d61726b657231:6578747261207374756666," + "abba:6d61726b657232:," + "cafe:6d61726b657233:6d6f72657374756666"); + const char *start = def; + const char *end; + + parse_static_tracepoint_marker_definition (start, &end, &marker); + + SELF_CHECK (marker.address == 0x1234); + SELF_CHECK (strcmp (marker.str_id, "marker1") == 0); + SELF_CHECK (strcmp (marker.extra, "extra stuff") == 0); + SELF_CHECK (end == strchr (start, ',')); + + start = end + 1; + parse_static_tracepoint_marker_definition (start, &end, &marker); + + SELF_CHECK (marker.address == 0xabba); + SELF_CHECK (strcmp (marker.str_id, "marker2") == 0); + SELF_CHECK (strcmp (marker.extra, "") == 0); + SELF_CHECK (end == strchr (start, ',')); + + start = end + 1; + parse_static_tracepoint_marker_definition (start, &end, &marker); + + SELF_CHECK (marker.address == 0xcafe); + SELF_CHECK (strcmp (marker.str_id, "marker3") == 0); + SELF_CHECK (strcmp (marker.extra, "morestuff") == 0); + SELF_CHECK (end == def + strlen (def)); +} + +} /* namespace tracepoint_tests */ +} /* namespace selftests */ + +void +_initialize_tracepoint_selftests () +{ + selftests::register_test + ("parse_static_tracepoint_marker_definition", + selftests::tracepoint_tests::test_parse_static_tracepoint_marker_definition); +} -- 2.30.2