[binutils-gdb] gdb: use all_threads() in for_each_thread()

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=f1fdd3164b86d15c97204fe9eaa5de57ae33f2bd

commit f1fdd3164b86d15c97204fe9eaa5de57ae33f2bd
Author: Markus Metzger <[email protected]>
Date:   Mon May 11 08:53:21 2026 +0000

    gdb: use all_threads() in for_each_thread()
    
    In for_each_thread(), we use all_threads_safe(), which allows deleting the
    thread.  This it not needed in the cases where it is currently used and it
    causes the iterator to get corrupted when threads are deleted in a nested
    all_threads_safe() iteration.
    
    One such scenario is as follows:
    - remote debugging in non-stop mode
    - one thread has hit a breakpoint
    - one thread exited but GDB does not know about it, yet
    - resume with 'continue -a'
    - the continue command uses for_each_thread() to proceed threads individually
    - the stopped thread starts an inline step-over (displaced stepping disabled)
    - update_thread_list() learns about the exit and deletes the thread
    - the safe iterator's m_next still points to the deleted thread
    
    Approved-By: Tom Tromey <[email protected]>

Diff:
---
 gdb/gdbthread.h | 9 ++++++++-
 gdb/thread.c    | 2 +-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/gdb/gdbthread.h b/gdb/gdbthread.h
index b3052b28d1a..1bdbf621982 100644
--- a/gdb/gdbthread.h
+++ b/gdb/gdbthread.h
@@ -796,7 +796,14 @@ void thread_change_ptid (process_stratum_target *targ,
 using for_each_thread_callback_ftype
   = gdb::function_view<void (thread_info *)>;
 
-/* Call CALLBACK once for each known thread.  */
+/* Call CALLBACK once for each known thread.
+
+   CALLBACK must not delete the thread.  To delete threads, use:
+
+     for (thread_info &t : all_threads_safe ())
+       if (some_condition ())
+	 delete &t;
+*/
 
 extern void for_each_thread (for_each_thread_callback_ftype callback);
 
diff --git a/gdb/thread.c b/gdb/thread.c
index 4f62ca280cd..110e58a70aa 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -605,7 +605,7 @@ find_thread_by_handle (gdb::array_view<const gdb_byte> handle,
 void
 for_each_thread (for_each_thread_callback_ftype callback)
 {
-  for (thread_info &tp : all_threads_safe ())
+  for (thread_info &tp : all_threads ())
     callback (&tp);
 }