FreeChainXenon/binutils-gdb
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Remove support for LinuxThreads and vendor 2.4 kernels w/ backported NPTL

Browse source 
Since we now rely on PTRACE_EVENT_CLONE being available (added in
Linux 2.5.46), we're relying on NPTL.

This commit removes the support for older LinuxThreads, as well as the
workarounds for vendor 2.4 kernels with NPTL backported.

 - Rely on tkill being available.

 - Assume gdb doesn't get cancel signals.

 - Remove code that checks the LinuxThreads restart and cancel signals
   in the inferior.

 - Assume that __WALL is available.

 - Assume that non-leader threads report WIFEXITED.

 - Thus, no longer need to send signal 0 to check whether threads are
   still alive.

 - Update comments throughout.

Tested on x86_64 Fedora 20, native and gdbserver.

gdb/ChangeLog:

	* configure.ac: Remove tkill checks.
	* configure, config.in: Regenerate.
	* linux-nat.c: Remove HAVE_TKILL_SYSCALL check.  Update top level
	comments.
	(linux_nat_post_attach_wait): Remove 'cloned' parameter.  Use
	__WALL.
	(attach_proc_task_lwp_callback): Don't set the cloned flag.
	(linux_nat_attach): Adjust.
	(kill_lwp): Remove HAVE_TKILL_SYSCALL check.  No longer fall back
	to 'kill'.
	(linux_handle_extended_wait): Use __WALL.  Don't set the cloned
	flag.
	(wait_lwp): Use __WALL.  Update comments.
	(running_callback, stop_and_resume_callback): Delete.
	(linux_nat_filter_event): Don't stop and resume all lwps. Don't
	check if the event LWP has previously exited.
	(check_zombie_leaders): Update comments.
	(linux_nat_wait_1): Use __WALL.
	(kill_wait_callback): Don't handle clone processes separately.
	Use __WALL instead.
	(linux_thread_alive): Delete.
	(linux_nat_thread_alive): Return true as long as the LWP is in the
	LWP list.
	(linux_nat_update_thread_list): Assume the kernel supports
	PTRACE_EVENT_CLONE.
	(get_signo): Delete.
	(lin_thread_get_thread_signals): Remove LinuxThreads references.
	No longer check __pthread_sig_restart / __pthread_sig_cancel in
	the inferior.
	* linux-nat.h (struct lwp_info) <cloned>: Delete field.
	* linux-thread-db.c: Update comments.
	(_initialize_thread_db): Remove LinuxThreads references.
	* nat/linux-waitpid.c (my_waitpid): No longer emulate __WALL.
	Pass down flags unmodified.
	* linux-waitpid.h (my_waitpid): Update documentation.

gdb/gdbserver/ChangeLog:

	* linux-low.c (linux_kill_one_lwp): Remove references to
	LinuxThreads.
	(kill_lwp): Remove HAVE_TKILL_SYSCALL check.  No longer fall back
	to 'kill'.
	(linux_init_signals): Delete.
	(initialize_low): Adjust.
	* thread-db.c (thread_db_init): Remove LinuxThreads reference.
This commit is contained in:
Pedro Alves 2015-12-17 14:20:51 +00:00
parent c3c874459b
commit 4a6ed09b0f
12 changed files with 168 additions and 538 deletions
Download patch file Download diff file Expand all files Collapse all files

18
gdb/linux-thread-db.c
View file

@ -54,11 +54,12 @@
created, thread IDs (usually, the result of pthread_self), and
thread-local variables.
The libthread_db interface originates on Solaris, where it is
both more powerful and more complicated. This implementation
only works for LinuxThreads and NPTL, the two glibc threading
libraries. It assumes that each thread is permanently assigned
to a single light-weight process (LWP).
The libthread_db interface originates on Solaris, where it is both
more powerful and more complicated. This implementation only works
for NPTL, the glibc threading library. It assumes that each thread
is permanently assigned to a single light-weight process (LWP). At
some point it also supported the older LinuxThreads library, but it
no longer does.
libthread_db-specific information is stored in the "private" field
of struct thread_info. When the field is NULL we do not yet have
@ -1717,10 +1718,9 @@ _initialize_thread_db (void)
/* Defer loading of libthread_db.so until inferior is running.
This allows gdb to load correct libthread_db for a given
executable -- there could be mutiple versions of glibc,
compiled with LinuxThreads or NPTL, and until there is
a running inferior, we can't tell which libthread_db is
the correct one to load. */
executable -- there could be multiple versions of glibc,
and until there is a running inferior, we can't tell which
libthread_db is the correct one to load. */
libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);