WIP: Introduce a compile-time flag to diagnose file locking issues #1368
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This is a standalone version of the libbacktrace library that I originally wrote for GCC. This is a copy of libbacktrace from GCC trunk, with all dependencies incorporated here.
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Great idea! 👍 That should help us with #1262 and others. Did you consider a run-time flag (e.g. I know you how much you dislike submodules... this is the situation were I usually use them to keep the PR small 😄 |
Yes. It's not working, due to Address Space Layout Randomization: that causes the stacktraces not to include symbols. Rather pointless, then.
No, I hate them. And with lots of reasons. Just try to rebase a patch series where a submodule was introduced in the middle. Just try it. |
Includes (among other things) support for compressed debug sections, a variety of bugfixes, and expanded test coverage.
Previous change (update from gcc trunk) broke 'make install'; this corrects the problem.
This brings in this patch: * elf.c (codes) [GENERATE_FIXED_HUFFMAN_TABLE]: Fix size to be 288. (main) [GENERATE_FIXED_HUFFMAN_TABLE]: Pass 288 to elf_zlib_inflate_table. Generate elf_zlib_default_dist_table. (elf_zlib_default_table): Update. (elf_zlib_default_dist_table): New static array. (elf_zlib_inflate): Use elf_zlib_default_dist_table for dist table for block type 1. * ztest.c (struct zlib_test): Add uncompressed_len. (tests): Initialize uncompressed_len field. Add new test case. (test_samples): Use uncompressed_len field.
Add required support files to the config subdirectory. Update dtest to be based on a statically linked program.
on the free list. Fixes #5 Fixes rust-lang/rust#29293 Fixes rust-lang/rust#37477
desired CRC is zero. (elf_add): Don't clear *found_sym and *found_dwarf if debuginfo.
* btest.c (check_open_files): New static function. (main): Call check_open_files.
2018-04-17 Ian Lance Taylor <[email protected]> * backtrace.c (backtrace_full): When testing whether we can allocate memory, call mmap directly, and munmap the memory. 2018-04-04 Jakub Jelinek <[email protected]> PR other/85161 * elf.c (elf_zlib_fetch): Fix up predefined macro names in test for big endian, only use 32-bit loads if endianity macros are predefined and indicate big or little endian. 2018-02-15 Jakub Jelinek <[email protected]> PR other/82368 * elf.c (SHT_PROGBITS): Undefine and define. 2018-02-14 Jakub Jelinek <[email protected]> PR other/82368 * elf.c (EM_PPC64, EF_PPC64_ABI): Undefine and define. (struct elf_ppc64_opd_data): New type. (elf_initialize_syminfo): Add opd argument, handle symbols pointing into the PowerPC64 ELFv1 .opd section. (elf_add): Read .opd section on PowerPC64 ELFv1, pass pointer to structure with .opd data to elf_initialize_syminfo. 2018-01-19 Tony Reix <[email protected]> * xcoff.c (xcoff_incl_compare): New function. (xcoff_incl_search): New function. (xcoff_process_linenos): Use bsearch to find include file. (xcoff_initialize_fileline): Sort include file information. Fixes #13
directly. Updates #13
Copied from GCC revision 256122.
Update to config.guess 2018-05-19 and config.sub 2018-05-24 from git://git.savannah.gnu.org/config.git revision 3a2a927f547ee478147008c3fda2adb8a2b2ebc4. This brings in musl support.
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This adds DWARF 5 support as well as an enhanced testsuite. Patch assembled by Than McIntosh.
This supports FreeBSD and NetBSD when /proc is not mounted.
Use an attribute rather than a comment when falling through a switch case. * internal.h (ATTRIBUTE_FALLTHROUGH): Define. * elf.c (elf_zlib_inflate): Use ATTRIBUTE_FALLTHROUGH.
* dwarf.c (resolve_string): Use > rather than >= to check whether string index extends past buffer. (resolve_addr_index): Similarly for address index.
PR debug/98716 * dwarf.c (read_v2_paths): Allocate zero entry for dirs and filenames. (read_line_program): Remove parameter u, change caller. Don't subtract one from dirs and filenames index. (read_function_entry): Don't subtract one from filenames index.
* Makefile.am (%_dwz): If dwz fails, use uncompressed debug info. * Makefile.in: Regenerate.
* configure.ac: Check for objcopy --add-gnu-debuglink by using objcopy --help. * configure: Regenerate
PR libbacktrace/98818 * dwarf.c (dwarf_buf_error): Add errnum parameter. Change all callers. * backtrace.h: Update backtrace_error_callback comment.
It's no longer necessary as file 0 is now set up in all cases. * dwarf.c (read_line_program): Don't special case file 0. (read_function_entry): Likewise. Fixes msysgit#69
Copied from GCC tip. Fixes msysgit#84
When I added the fields in 2019-12-13 I forgot to initialize them. * dwarf.c (build_address_map): Initialize DWARF 5 fields of unit.
* dwarf.c (find_address_ranges): Handle skeleton units. (read_function_entry): Likewise.
Patch from Rui Ueyama, who says: libbacktrace occasionally fails to decompress compressed debug info even though the sections contain valid zlib streams. The cause of the issue is an off-by-one error. If a zlib data block is a plain data (uncompressed data), the next two bytes contain the size of the block. These two bytes value is byte- aligned, so if we read-ahead more than 8 bits, we need to unread it. So, the correct condition to determine whether or not we need to unread a byte is bits >= 8 and not bits > 8. Due to this error, if the last read bits happened to end at a byte boundary, the next byte would be skipped. That caused the decompression failure. This bug was originally reported against the mold linker. rui314/mold#402 * elf.c (elf_zlib_inflate): Don't skip initial aligned byte in uncompressed block.
Patch by Xi Ruoyao. * configure.ac: Use grep instead of fgrep. * configure: Regenerate.
* Makefile.am (MAKETESTS): New variable split out of TESTS. (CLEANFILES): Replace TESTS with BUILDTESTS and MAKETESTS. * Makefile.in: Regenerate. Fixes msysgit#81
* macho.c (backtrace_initialize) [HAVE_MACH_O_DYLD_H]: Don't exit loop if we can't find debug info for one shared library. For msysgit#85
QNX uses sys/link.h rather than link.h for dl_iterate_phdr Fixes msysgit#86 * configure.ac: Check for sys/link.h. Use either link.h or sys/link.h when checking for dl_iterate_phdr. * elf.c: Include sys/link.h if available. * configure, config.h.in: Regenerate.
In rust-lang/rust#39468 it was discovered that this could cause a crash in libbacktrace due to freeing uninitialized memory, and this specific instance was fixed in rust-lang/rust#39509
This updates the local declaration of `str_size` to always be 4 bytes instead of platform-dependent as its initialization later on only fills in 4 bytes instead of all the bytes of `size_t`. Originally reported as rust-lang/rust#28447 this was fixed in rust-lang/rust#30908
Note: as we target MINGW here, we still want to look up the symbols via the DWARF method (the native Windows way would be to call the SymFromAddr() function, but that would require .pdb files which MINGW does not produce). Signed-off-by: Johannes Schindelin <[email protected]>
Signed-off-by: Johannes Schindelin <[email protected]>
Merge the `windows` branch of https://github.com/dscho/libbacktrace (itself a fork of https://github.com/ianlancetaylor/libbacktrace) into compat/libbacktrace/, for use primarily by compat/mingw.c to generate (you guessed it) stack traces. This trick was performed by: git fetch https://github.com/dscho/libbacktrace windows git read-tree --prefix=compat/libbacktrace/ -u FETCH_HEAD git reset $(git commit-tree -m "Add libbacktrace" \ -p HEAD -p FETCH_HEAD $(git write-tree)) and then amending the commit to edit the commit message ;-) Signed-off-by: Johannes Schindelin <[email protected]>
Git's DEVELOPER CFLAGS do not allow it. Signed-off-by: Johannes Schindelin <[email protected]>
This is not really the proper way to include them, but it will have to do for now. Signed-off-by: Johannes Schindelin <[email protected]>
On Windows, it is not possible to overwrite files as long as they are in use. This is particularly funny (not!) when the same process still holds open file handles to that file, and it notoriously hard to debug. Let's add a compile-time option to output stacktraces to the offending calls when we fail to overwrite/remove them. Note: it has to be a compile time option because we would have to turn off ASLR otherwise (and it is too good of a first line of defense to just turn off). Signed-off-by: Johannes Schindelin <[email protected]>
Signed-off-by: Johannes Schindelin <[email protected]>
Signed-off-by: Johannes Schindelin <[email protected]>
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There seem to be some problems with Git, or with GVFS Git, where git.exe itself would have open file handles to files it wants to overwrite. That does not work.
To make this notoriously-hard-to-debug problem easier to diagnose, let's add a mode where Git for Windows records stacktraces for every file it opened (forgetting about those it already closed again), and then show those stacktraces when we detect that we cannot overwrite or delete a given file.
This is a Work-In-Progress, both to serve as a back-up, as well as to be open to interested lurkers who may want to take a stab at it (as I won't be able to work on this for at least a week).