public inbox for gdb-cvs@sourceware.org
help / color / mirror / Atom feed
* [binutils-gdb] gdbserver/qXfer::threads, prepare_to_access_memory=>target_pause_all
@ 2022-04-14 19:23 Pedro Alves
0 siblings, 0 replies; only message in thread
From: Pedro Alves @ 2022-04-14 19:23 UTC (permalink / raw)
To: gdb-cvs
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=330d63093c562a4b221835832c5e4f767dc623c3
commit 330d63093c562a4b221835832c5e4f767dc623c3
Author: Pedro Alves <pedro@palves.net>
Date: Tue Mar 29 12:57:17 2022 +0100
gdbserver/qXfer::threads, prepare_to_access_memory=>target_pause_all
handle_qxfer_threads_proper needs to pause all threads even if the
target can read memory when threads are running, so use
target_pause_all instead, which is what the Linux implementation of
prepare_to_access_memory uses. (Only Linux implements this hook.)
A following patch will make the Linux backend be able to access memory
when threads are running, and thus will also make
prepare_to_access_memory do nothing, which would cause testsuite
regressions without this change.
Change-Id: I127fec7246b7c45b60dfa7341e781606bf54b5da
Diff:
---
gdbserver/server.cc | 51 ++++++++++++++++-----------------------------------
1 file changed, 16 insertions(+), 35 deletions(-)
diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index 9f52d6e63fe..e43a40a9b1f 100644
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -1691,47 +1691,28 @@ handle_qxfer_threads_worker (thread_info *thread, struct buffer *buffer)
static bool
handle_qxfer_threads_proper (struct buffer *buffer)
{
- client_state &cs = get_client_state ();
-
- scoped_restore_current_thread restore_thread;
- scoped_restore save_current_general_thread
- = make_scoped_restore (&cs.general_thread);
-
buffer_grow_str (buffer, "<threads>\n");
- process_info *error_proc = find_process ([&] (process_info *process)
- {
- /* The target may need to access memory and registers (e.g. via
- libthread_db) to fetch thread properties. Prepare for memory
- access here, so that we potentially pause threads just once
- for all accesses. Note that even if someday we stop needing
- to pause threads to access memory, we will need to be able to
- access registers, or other ptrace accesses like
- PTRACE_GET_THREAD_AREA. */
-
- /* Need to switch to each process in turn, because
- prepare_to_access_memory prepares for an access in the
- current process pointed to by general_thread. */
- switch_to_process (process);
- cs.general_thread = current_thread->id;
-
- int res = prepare_to_access_memory ();
- if (res == 0)
- {
- for_each_thread (process->pid, [&] (thread_info *thread)
- {
- handle_qxfer_threads_worker (thread, buffer);
- });
+ /* The target may need to access memory and registers (e.g. via
+ libthread_db) to fetch thread properties. Even if don't need to
+ stop threads to access memory, we still will need to be able to
+ access registers, and other ptrace accesses like
+ PTRACE_GET_THREAD_AREA that require a paused thread. Pause all
+ threads here, so that we pause each thread at most once for all
+ accesses. */
+ if (non_stop)
+ target_pause_all (true);
- done_accessing_memory ();
- return false;
- }
- else
- return true;
+ for_each_thread ([&] (thread_info *thread)
+ {
+ handle_qxfer_threads_worker (thread, buffer);
});
+ if (non_stop)
+ target_unpause_all (true);
+
buffer_grow_str0 (buffer, "</threads>\n");
- return error_proc == nullptr;
+ return true;
}
/* Handle qXfer:threads:read. */
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2022-04-14 19:23 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-04-14 19:23 [binutils-gdb] gdbserver/qXfer::threads, prepare_to_access_memory=>target_pause_all Pedro Alves
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).