[PATCH v2] USE_SEIZE: fix detaching from stopped processes

[Dmitry V. Levin]

On Wed, Jun 19, 2013 at 12:58:13PM +0200, Denys Vlasenko wrote:
> V2: check WSTOPSIG(status) == syscall_trap_sig, not SIGTRAP.
> Add comments explaining what we think about the process status
> in detach() at various steps. Simplify PTRACE_CONT
> in wait loop since now syscall_trap_sig can't be seen there.
> Verified that tests/detach works.

With this patch,
tests/detach-running fails (detach hangs) in use_seize case,
tests/detach-sleeping fails (detach hangs) in !use_seize case.

> * strace.c (detach) [USE_SEIZE]: If PTRACE_SEIZE API is in use, stop
> the tracee using PTRACE_INTERRUPT instead of sending it a SIGSTOP.
> In a subsequent waitpid loop, wait for either SIGSTOP or syscall_trap_sig.

detach() uses no USE_SEIZE ifdefs, so there should be no [USE_SEIZE].


-- 
ldv
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: not available
URL: <http://lists.strace.io/pipermail/strace-devel/attachments/20130619/c8e92aab/attachment.bin>