Re: [PATCH v4 0/7] Remote fork events

["Breazeal, Don" <donb at codesourcery dot com>]

Ping.

Full remote follow fork patch series includes:
1/7: https://sourceware.org/ml/gdb-patches/2015-01/msg00686.html
2/7: https://sourceware.org/ml/gdb-patches/2015-01/msg00687.html
3/7: https://sourceware.org/ml/gdb-patches/2015-01/msg00689.html
4/7: https://sourceware.org/ml/gdb-patches/2015-01/msg00690.html
5/7: https://sourceware.org/ml/gdb-patches/2015-01/msg00685.html
6/7: https://sourceware.org/ml/gdb-patches/2015-01/msg00684.html
7/7: https://sourceware.org/ml/gdb-patches/2015-01/msg00688.html

Thanks,
--Don

On 1/25/2015 1:58 PM, Breazeal, Don wrote:
> 
> From: Don Breazeal <donb@codesourcery.com>
> Subject: [PATCH v4 0/7] Remote fork events
> In-Reply-To: <54C236B9.8060200@redhat.com>
> 
> 
> This is an update to the patch series implementing remote follow-fork.
> This update only implements fork and vfork events, omitting exec events
> for now.
> 
> The series has been renumbered, since the numbering of the original patch
> series has little relevance now.  Let me know if I should maintain the
> original numbering.
> 
> The primary difference between this series and previous versions is that
> it includes support for 'target remote' as well as extended-remote.  It
> also eliminates the vFollowFork packet used in previous versions and uses
> the qSupported packet to determine if fork events are supported by
> gdbserver.
> 
> The new series includes seven patches as follows:
> 
> 1/7: Preparatory patch that implements qSupported support for fork events
>      and associated mechanisms.
> 
> 2/7: Implements functions to clone breakpoint lists in gdbserver.
> 
> 3/7: Implements follow fork for 'fork' but not 'vfork' and for
> extended-remote
>      targets only.  Note subject line was garbled, see ERRATA below.
> 
> 4/7: Extends follow fork for 'fork' to 'target remote' as well as
>      extended-remote.
> 
> 5/7: Adds the architecture-specific pieces of follow-fork that allows
>      hardware watchpoints to be inherited by a forked child.
> 
> 6/7: Adds follow fork for 'vfork'.
> 
> 7/7: Adds catchpoints for 'fork' and 'vfork', along with support for
>      killing a process that has forked but has not been followed.
> 
> 
> ERRATA:
> I have to apologize in advance for a few minor formatting and coding
> errors, listed below.  I decided that these were trivial enough that
> they didn't warrant the delay required to go through the whole rebase/test
> cycle.  The issues are:
> 
> 4/7: in linux-low.c there is a blank line containing spaces.
> 4/7: in remote.c, I left a /* XXX */ comment.
> 4/7: in remote.c there is an unnecessary static declaration of
>      extended_remote_kill
> 
> The subject line of patch 3 was garbled somehow.  Sent on 25-Jan-2015,
> it reads "Re: [PATCH v4 3/7 v3] Extended-remote Linux follow fork" when
> it should read "[PATCH v4 3/7] Extended-remote-Linux follow fork". My
> incompetent use of --in-reply-to with git send-email, I'm sure.
> 
> 
> TESTING:
> Testing was mostly done using x86_64 Ubuntu, with the exception of the
> architecture-specific patch, #5.  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
> 
> 
>