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[PATCH v5 0/6] Remote fork events
- From: Don Breazeal <donb at codesourcery dot com>
- To: <gdb-patches at sourceware dot org>, <palves at redhat dot com>
- Date: Thu, 26 Feb 2015 16:46:11 -0800
- Subject: [PATCH v5 0/6] Remote fork events
- Authentication-results: sourceware.org; auth=none
- References: <54C566F2 dot 2020302 at codesourcery dot com>
This is an update to the patch series implementing remote follow-fork.
This update only implements fork and vfork events for extended remote,
omitting exec events and 'target remote' for now.
Changes from the previous version include:
* Removed 'target remote' support, which is deferred for later.
* Fixes per review comments, notably
- issues with unpushing the target after detach or kill
- reorganizing/renaming some things, both to match the
native implementation better and for just plain better
organization.
- fixed and/or improved some of the event handling code.
* Also added documentation to each individual patch, rather than
saving it all for a subsequent 'documentation patch'.
The new series includes six patches as follows:
1/6: Preparatory patch that implements qSupported support for fork events
and associated mechanisms.
2/6: Implements functions to clone breakpoint lists in gdbserver.
3/6: Implements follow fork for 'fork' but not 'vfork', for
extended-remote targets only.
4/6: Adds the architecture-specific pieces of follow-fork that allows
hardware watchpoints to be inherited by a forked child.
This patch was previously approved, although I have added a
trivial change to gdb/NEWS in this patch.
5/6: Adds follow fork for 'vfork'.
6/6: Adds catchpoints for 'fork' and 'vfork', along with support for
killing a process that has forked but has not been followed.
TESTING:
Testing was mostly done using x86_64 Ubuntu, with the exception of the
architecture-specific patch, #4. There are a few anomalies that show
up, but don't signify any problem.
- Intermediate patches show failures due to the lack of features
implemented in subsequent patches, like missing hardware watchpoint
or catchpoint support.
- Some vfork tests fail due to the lack of exec event support.
- There are a couple of tests that show new failures that actually
fail in the current mainline. Details of these are as follows:
* when vfork events are enabled, gdb.base/disp-step-syscall.exp
shows PASS => FAIL in .sum diffs. The test actually always
fails. With native/master, we see
stepi^M
FAIL: gdb.base/disp-step-syscall.exp: vfork: stepi vfork insn
(timeout)
With remote and extended-remote/master, we see a bogus PASS result:
stepi^M
[Inferior 1 (process 9399) exited normally]^M
(gdb) PASS: gdb.base/disp-step-syscall.exp: vfork: stepi vfork insn
The criteria to pass that test are pretty lax:
gdb_test "stepi" ".*" "stepi $syscall insn"
* Similarly, once vfork events are enabled, gdb.base/watch-vfork.exp
shows PASS => FAIL in .sum diffs. This test also always fails. With
native/master, we see this:
continue^M
Continuing.^M
FAIL: gdb.base/watch-vfork.exp: Watchpoint triggers after vfork
(sw) (timeout)
With extended-remote/master, we see this:
continue
Continuing.
[Inferior 1 (process 18866) exited normally]
(gdb) FAIL: gdb.base/watch-vfork.exp: Watchpoint triggers after
vfork (sw) (the program exited)
But once vfork events are enabled, we see:
continue
Continuing.
Detaching from process 17405
FAIL: gdb.base/watch-vfork.exp: Watchpoint triggers after vfork
(sw) (timeout)
which more-or-less matches the native/master behavior.
Thanks,
--Don