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| author | David Malcolm <dmalcolm@redhat.com> | 2016-10-25 19:24:01 +0000 |
|---|---|---|
| committer | David Malcolm <dmalcolm@gcc.gnu.org> | 2016-10-25 19:24:01 +0000 |
| commit | f5ea989d50a3c4965667ad40807f18737f231b91 (patch) | |
| tree | 577d6785b1d140e60c6a5523ac860ed50ec2e5e3 /libcpp | |
| parent | dd90ca33e8596f23354edc654528899feb12ff8a (diff) | |
| download | gcc-f5ea989d50a3c4965667ad40807f18737f231b91.zip gcc-f5ea989d50a3c4965667ad40807f18737f231b91.tar.gz gcc-f5ea989d50a3c4965667ad40807f18737f231b91.tar.bz2 | |
input.c/libcpp: fix lifetimes of path buffers
Running "make selftest-valgrind" showed various leaks of the form:
408 bytes in 24 blocks are definitely lost in loss record 572 of 679
at 0x4A0645D: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x1B0D057: xmalloc (xmalloc.c:148)
by 0x1ACCAA1: append_file_to_dir(char const*, cpp_dir*) [clone .isra.3] (files.c:1567)
by 0x1ACD56F: _cpp_find_file (files.c:390)
by 0x1ACF8FB: cpp_read_main_file(cpp_reader*, char const*) (init.c:632)
by 0x1AB3D97: selftest::lexer_test::lexer_test(selftest::line_table_case const&, char const*, selftest::lexer_test_options*) (input.c:2014)
by 0x1AB792B: selftest::test_lexer_string_locations_u8(selftest::line_table_case const&) (input.c:2713)
by 0x1ABA22A: selftest::for_each_line_table_case(void (*)(selftest::line_table_case const&)) (input.c:3227)
by 0x1ABA381: selftest::input_c_tests() (input.c:3260)
by 0x1A295F1: selftest::run_tests() (selftest-run-tests.c:62)
by 0xF20DC4: toplev::run_self_tests() (toplev.c:2076)
by 0xF20FCD: toplev::main(int, char**) (toplev.c:2153)
Fix the leak by freeing the file->path in destroy_cpp_file.
However, doing so would lead to a use-after-free in input.c's file cache
since the filenames in this cache are the libcpp file->path buffers.
Hence we need to ensure that any references to the file in the input.c
cache are purged before cleaning up file->path. This is normally done
by the temp_source_file dtor. Hence we need to reorder things to that
the temp_source_file dtor runs before cleaning up the cpp_parser. The
patch does this by introducing a wrapper class around cpp_parser *, so
that the dtor can run after the dtor for temp_source_file.
gcc/ChangeLog:
* input.c (fcache::file_patch): Add comment about lifetime.
(selftest::cpp_reader_ptr): New class.
(selftest::lexer_test): Convert m_parser from cpp_reader *
to a cpp_reader_ptr, and move m_tempfile to after it.
(selftest::lexer_test::lexer_test): Update for above reordering.
(lexer_test::~lexer_test): Move cleanup of m_parser to
cpp_reader_ptr's dtor.
libcpp/ChangeLog:
* files.c (destroy_cpp_file): Free file->path.
From-SVN: r241536
Diffstat (limited to 'libcpp')
| -rw-r--r-- | libcpp/ChangeLog | 4 | ||||
| -rw-r--r-- | libcpp/files.c | 1 |
2 files changed, 5 insertions, 0 deletions
diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog index 5ff0aad..9083bda 100644 --- a/libcpp/ChangeLog +++ b/libcpp/ChangeLog @@ -1,5 +1,9 @@ 2016-10-25 David Malcolm <dmalcolm@redhat.com> + * files.c (destroy_cpp_file): Free file->path. + +2016-10-25 David Malcolm <dmalcolm@redhat.com> + * include/line-map.h (line_maps::~line_maps): New dtor. (location_adhoc_data_fini): Delete decl. * line-map.c (line_maps::~line_maps): New dtor. diff --git a/libcpp/files.c b/libcpp/files.c index e859dfe..2c50e6c 100644 --- a/libcpp/files.c +++ b/libcpp/files.c @@ -1132,6 +1132,7 @@ destroy_cpp_file (_cpp_file *file) { free ((void *) file->buffer_start); free ((void *) file->name); + free ((void *) file->path); free (file); } |