Skip to content

drgn 0.0.21

Choose a tag to compare

View all tags
@osandov osandov released this 12 Oct 19:14
· 1465 commits to main since this release
v0.0.21
40f2d4b

This release adds lots of new helpers and fixes some important bugs.

New features:

  • Helpers for lockless linked lists in the Linux kernel were added: drgn.helpers.linux.llist. Contributed by Imran Khan.
  • A helper to find the slab cache that a virtual address came from was added: drgn.helpers.linux.slab.find_containing_slab_cache(). Contributed by Nhat Pham.
  • A drgn.helpers.common package was created to contain helpers that can be used with any program (which may have program-specific additional behavior).
  • A helper to identify an arbitrary address (e.g., as a symbol or slab object) was added: drgn.helpers.common.memory.identify_address(). Contributed by Nhat Pham.
  • PageFoo() helpers to check various struct page flags were added to drgn.helpers.linux.mm.
  • Helpers for working with compound pages were added to drgn.helpers.linux.mm: compound_head(), compound_nr(), compound_order(), and page_size().
  • A helper to get the CPU that a task last ran on was added: drgn.helpers.linux.sched.task_cpu().
  • Automatic pretty-printing in IPython/Jupyter of drgn.Object, drgn.Type, drgn.StackTrace, and drgn.StackFrame was added. Contributed by Shung-Hsi Yu.
  • drgn.StackTrace.prog was added as a way to get the program that a stack trace came from.

Bug fixes:

  • Getting stack traces from a kernel core dump of threads that were running at the time of the crash was fixed for Linux < 4.9 and >= 5.16.
  • drgn.helpers.linux.per_cpu() and per_cpu_ptr() were fixed to work for per-CPU variables defined in kernel modules.
  • Reading from pages that were excluded by makedumpfile was changed to return zeroes instead of raising a FaultError. This is unfortunately necessary because we cannot distinguish between pages that were excluded because their contents were zero and pages that were excluded for other reasons. Contributed by Glen McCready.
  • A segfault when looking for a variable in a stack frame caused by strange debug symbols emitted by Clang in certain situations was fixed.
  • A reference leak every time a FaultError is raised inside of drgn was fixed.
  • A use after free when setting an object from a part of itself in libdrgn was fixed. The Python interface is not affected.
  • The recommendation for how to get VMCOREINFO in QEMU guest memory dumps was fixed to suggest the correct Linux kernel configuration options.
  • A spelling error in a DWARF parsing error message was fixed. Contributed by Michel Alexandre Salim.

API changes:

  • escape_ascii_character(), escape_ascii_string(), decode_flags(), and decode_enum_type_flags() were moved from drgn.helpers to drgn.helpers.common.format.
  • enum_type_to_class() was moved from drgn.helpers to drgn.helpers.common.type.

Documentation:

  • openSUSE installation instructions were added.
  • libkdumpfile installation instructions were updated to reflect that it is now packaged on some Linux distributions.
  • Python type signatures are now formatted more concisely in the documentation.
  • Overloaded helpers are now documented more concisely.
  • Various small editorial and formatting issues were fixed.

Other improvements:

  • Linux kernel support was tested up to Linux 6.0.
  • drgn.helpers.linux.bpf.cgroup_bpf_prog_for_each() was updated to work on Linux 6.0.

Internals:

  • Some racy stack tracing unit tests were fixed.
  • Linux kernel memory management helper unit tests were enabled on AArch64.
  • The VM testing setup no longer depends on BusyBox.
  • -Wimplicit-fallthrough was enabled for builds.
  • A syscall number table and normalized machine name were added to util.py
    for use in test cases and the VM testing setup.
  • Some renaming was done to prepare for the upcoming module API.
  • The libdrgn-internal string_builder API was improved.
Assets 2
Loading