Merge branch 'master' into '6.0/stage' #17
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
![github-actions[bot]](https://avatars.githubusercontent.com/in/15368?s=80&v=4){kind=small}
Signed-off-by: Omar Sandoval <[email protected]>
Really it's more of a test program than an example program. It's useful for benchmarking, testing with valgrind, etc. It's not built by default, but it can be built manually with: $ make -C build/temp.* examples/load_debug_info And run with: $ ./build/temp.*/examples/load_debug_info Signed-off-by: Omar Sandoval <[email protected]>
It's awkward to make callers cast to char *. Signed-off-by: Omar Sandoval <[email protected]>
Variables can have a non-default endianity. Handle it and clean up variable endian handling. Signed-off-by: Omar Sandoval <[email protected]>
Compile-time constants have DW_AT_const_value instead of DW_AT_location. We can translate those to a value object. Signed-off-by: Omar Sandoval <[email protected]>
setuptools recently started warning if distutils is imported before it. Signed-off-by: Omar Sandoval <[email protected]>
Signed-off-by: Omar Sandoval <[email protected]>
posix_memalign() doesn't have the restriction that the size must be a multiple of the alignment like aligned_alloc() does in C11. Signed-off-by: Omar Sandoval <[email protected]>
The only major change to the folly F14 implementation since I originally
ported it is commit 3d169f4365cf ("memory savings for F14 tables with
explicit reserve()"). That is a small improvement for small tables and a
large improvement for vector tables, which are about to be added.
Signed-off-by: Omar Sandoval <[email protected]>
The folly F14 implementation provides 3 storage policies: value, node, and vector. The default F14FastMap/F14FastSet chooses between the value and vector policies based on the value size. We currently only implement the value policy, as the node policy is easy to emulate and the vector policy would've added more complexity. This adds support for the vector policy (adding even more C abuse :) and automatically chooses the policy the same way as folly. It'd be easy to add a way to choose the policy if needed. Signed-off-by: Omar Sandoval <[email protected]>
Clean up the coding style of the remaining few places that the last couple of changes didn't rewrite. Signed-off-by: Omar Sandoval <[email protected]>
sdimitro
approved these changes
Jul 20, 2020
drgn.h is generated from drgn.h.in since commit d60c6a1 ("libdrgn: add register information to platform"). Signed-off-by: Omar Sandoval <[email protected]>
3.16 is EOL and no longer included in the list of releases. Signed-off-by: Omar Sandoval <[email protected]>
My work VPN is apparently closing HTTP connections prematurely, which exposed that urllib won't catch incomplete reads if copied through shutil.copyfileobj(). Check it explicitly. Signed-off-by: Omar Sandoval <[email protected]>
Make the KASLR offset available to Python in a new drgn.helpers.linux.boot module, and move pgtable_l5_enabled() there, too. Signed-off-by: Omar Sandoval <[email protected]>
Signed-off-by: Omar Sandoval <[email protected]>
PyPI's RST parser apparently doesn't know the highlight directive, which snuck into the README in commit 4de147e ("Add CONTRIBUTING.rst"). Use code-block instead. Signed-off-by: Omar Sandoval <[email protected]>
Signed-off-by: Omar Sandoval <[email protected]>
prakashsurya
approved these changes
Jul 29, 2020
delphix-devops-bot
pushed a commit
that referenced
this pull request
Feb 1, 2025
We have a very old feature request to support searching for vmlinux and kernel modules in a directory specified by the user. This is useful, for example, if someone is given a vmcore and the corresponding kernel files. Now that we have the flexibility of the module and debug info options APIs, we can finally support it and add a command line option. Closes #17. Signed-off-by: Omar Sandoval <[email protected]>
delphix-devops-bot
pushed a commit
that referenced
this pull request
Sep 27, 2025
The CI has intermittently been hitting the following test failures on
Python 3.8 with Clang:
======================================================================
ERROR: test_task_cpu (tests.linux_kernel.helpers.test_sched.TestSched)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/runner/work/drgn/drgn/tests/linux_kernel/helpers/test_sched.py", line 40, in test_task_cpu
with fork_and_stop(os.sched_setaffinity, 0, (cpu,)) as (pid, _):
File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/contextlib.py", line 113, in __enter__
return next(self.gen)
File "/home/runner/work/drgn/drgn/tests/linux_kernel/__init__.py", line 203, in fork_and_stop
ret = pickle.load(pipe_r)
EOFError: Ran out of input
The EOFError occurs because the forked process segfaults immediately:
python[132]: segfault at 7f8f87085014 ip 00007f8f891e9774 sp 00007ffccf7acf00 error 4 in ld-linux-x86-64.so.2[16774,7f8f891d5000+2a000] likely on CPU 0 (core 0, socket 0)
The segfault is on dereferencing cache_new in in _dl_load_cache_lookup()
in ld-linux here:
https://sourceware.org/git/?p=glibc.git;a=blob;f=elf/dl-cache.c;h=88bf78ad7c914b02109d6ddef7e08c0e8fd4574d;hb=f94f6d8a3572840d3ba42ab9ace3ea522c99c0c2#l489
Which is coming from a libomp fork handler:
#0 0x00007f5566f9d774 in _dl_load_cache_lookup (name=name@entry=0x7f55654afde6 "libmemkind.so")
at ./elf/dl-cache.c:498
#1 0x00007f5566f91982 in _dl_map_object (loader=loader@entry=0x55f8a170b670,
name=name@entry=0x7f55654afde6 "libmemkind.so", type=type@entry=2, trace_mode=trace_mode@entry=0,
mode=mode@entry=-1879048191, nsid=<optimized out>) at ./elf/dl-load.c:2193
#2 0x00007f5566f959a9 in dl_open_worker_begin (a=a@entry=0x7fffcf5851f0) at ./elf/dl-open.c:534
#3 0x00007f5566b4ab08 in __GI__dl_catch_exception (exception=exception@entry=0x7fffcf585050,
operate=operate@entry=0x7f5566f95900 <dl_open_worker_begin>, args=args@entry=0x7fffcf5851f0)
at ./elf/dl-error-skeleton.c:208
#4 0x00007f5566f94f9a in dl_open_worker (a=a@entry=0x7fffcf5851f0) at ./elf/dl-open.c:782
#5 0x00007f5566b4ab08 in __GI__dl_catch_exception (exception=exception@entry=0x7fffcf5851d0,
operate=operate@entry=0x7f5566f94f60 <dl_open_worker>, args=args@entry=0x7fffcf5851f0)
at ./elf/dl-error-skeleton.c:208
#6 0x00007f5566f9534e in _dl_open (file=<optimized out>, mode=-2147483647, caller_dlopen=0x7f55653fa882, nsid=-2,
argc=9, argv=<optimized out>, env=0x55f8a1477e10) at ./elf/dl-open.c:883
#7 0x00007f5566a6663c in dlopen_doit (a=a@entry=0x7fffcf585460) at ./dlfcn/dlopen.c:56
#8 0x00007f5566b4ab08 in __GI__dl_catch_exception (exception=exception@entry=0x7fffcf5853c0, operate=<optimized out>,
args=<optimized out>) at ./elf/dl-error-skeleton.c:208
#9 0x00007f5566b4abd3 in __GI__dl_catch_error (objname=0x7fffcf585418, errstring=0x7fffcf585420,
mallocedp=0x7fffcf585417, operate=<optimized out>, args=<optimized out>) at ./elf/dl-error-skeleton.c:227
#10 0x00007f5566a6612e in _dlerror_run (operate=operate@entry=0x7f5566a665e0 <dlopen_doit>,
args=args@entry=0x7fffcf585460) at ./dlfcn/dlerror.c:138
#11 0x00007f5566a666c8 in dlopen_implementation (dl_caller=<optimized out>, mode=<optimized out>, file=<optimized out>)
at ./dlfcn/dlopen.c:71
#12 ___dlopen (file=<optimized out>, mode=<optimized out>) at ./dlfcn/dlopen.c:81
#13 0x00007f55653fa882 in ?? () from /usr/lib/llvm-14/lib/libomp.so.5
#14 0x00007f5565413556 in ?? () from /usr/lib/llvm-14/lib/libomp.so.5
#15 0x00007f5565421d1a in ?? () from /usr/lib/llvm-14/lib/libomp.so.5
#16 0x00007f5566ac0fc1 in __run_fork_handlers (who=who@entry=atfork_run_child, do_locking=do_locking@entry=true)
at ./posix/register-atfork.c:130
#17 0x00007f5566ac08d3 in __libc_fork () at ./posix/fork.c:108
#18 0x00007f5566e108ad in os_fork_impl (module=<optimized out>) at ./Modules/posixmodule.c:6250
#19 os_fork (module=<optimized out>, _unused_ignored=<optimized out>) at ./Modules/clinic/posixmodule.c.h:2750
This doesn't happen in Python 3.9, which I bisected to CPython commit
45a78f906d2d ("bpo-44434: Don't call PyThread_exit_thread() explicitly
(GH-26758)") (in v3.11, backported to v3.9.6).
That commit describes a different symptom where the process aborts
because libgcc_s can't be loaded. I don't understand how that issue can
cause our crash, but the fix appears to be the same. The discussion also
suggests a workaround: linking to libgcc_s explicitly.
Apply the workaround, which appears to fix our problem. We only do this
for the CI and not for the general build for a few reasons:
1. I'm nervous about explicitly linking to this low-level library
unconditionally, and the logic to decide when it's necessary (only
for Python 3.8 and glibc) isn't worth the trouble.
2. The situation required to hit it (drgn + Python threading + fork) is
unlikely outside of our test suite.
3. Python 3.8 is EOL.
4. Builds with libkdumpfile already pull in libgcc_s via libkdumpfile ->
libsnappy -> libstdc++ -> libgcc_s.
Signed-off-by: Omar Sandoval <[email protected]>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
No description provided.