* [Qemu-devel] [Bug 1031920] [NEW] Linux user gdbserver does not respond to remote `Ctrl-C' interrupts
@ 2012-08-01 20:23 Meador Inge
2015-10-14 15:27 ` [Qemu-devel] [Bug 1031920] " thierry bultel
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Meador Inge @ 2012-08-01 20:23 UTC (permalink / raw)
To: qemu-devel
Public bug reported:
The bug was reproduced in a recent mainline build for ARM Linux by
starting emulation with a gdbserver:
$ qemu-arm -g 1234 a.out
and then connecting from gdb:
(gdb) target remote :1234
Remote debugging using :1234
[New Remote target]
[Switching to Remote target]
0x00008ba8 in _start ()
(gdb) b main
Breakpoint 1 at 0x8cb0: file hello.c, line 5.
(gdb) cont
Continuing.
Breakpoint 1, main (argc=1, argv=0xf6fff24c) at hello.c:5
5 int n = 0;
(gdb) l
1 #include <stdio.h>
2
3 int main (int argc, char **argv)
4 {
5 int n = 0;
6
7 for (;;) {
8 printf ("Hello, World!\n");
9 sleep (5);
10 }
(gdb) cont
Continuing.
^C^CInterrupted while waiting for the program.
Give up (and stop debugging it)? (y or n) y
Notice that the `Ctrl-C' interrupts are ignored.
** Affects: qemu
Importance: Undecided
Status: New
** Description changed:
- The bug was reproduce in a recent mainline build for ARM Linux by
+ The bug was reproduced in a recent mainline build for ARM Linux by
starting emulation with a gdbserver:
$ qemu-arm -g 1234 a.out
and then connecting from gdb:
(gdb) target remote :1234
Remote debugging using :1234
[New Remote target]
[Switching to Remote target]
0x00008ba8 in _start ()
(gdb) b main
Breakpoint 1 at 0x8cb0: file hello.c, line 5.
(gdb) cont
Continuing.
Breakpoint 1, main (argc=1, argv=0xf6fff24c) at hello.c:5
5 int n = 0;
(gdb) l
1 #include <stdio.h>
- 2
+ 2
3 int main (int argc, char **argv)
4 {
5 int n = 0;
- 6
+ 6
7 for (;;) {
8 printf ("Hello, World!\n");
9 sleep (5);
10 }
(gdb) cont
Continuing.
^C^CInterrupted while waiting for the program.
Give up (and stop debugging it)? (y or n) y
Notice that the `Ctrl-C' interrupts are ignored.
--
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1031920
Title:
Linux user gdbserver does not respond to remote `Ctrl-C' interrupts
Status in QEMU:
New
Bug description:
The bug was reproduced in a recent mainline build for ARM Linux by
starting emulation with a gdbserver:
$ qemu-arm -g 1234 a.out
and then connecting from gdb:
(gdb) target remote :1234
Remote debugging using :1234
[New Remote target]
[Switching to Remote target]
0x00008ba8 in _start ()
(gdb) b main
Breakpoint 1 at 0x8cb0: file hello.c, line 5.
(gdb) cont
Continuing.
Breakpoint 1, main (argc=1, argv=0xf6fff24c) at hello.c:5
5 int n = 0;
(gdb) l
1 #include <stdio.h>
2
3 int main (int argc, char **argv)
4 {
5 int n = 0;
6
7 for (;;) {
8 printf ("Hello, World!\n");
9 sleep (5);
10 }
(gdb) cont
Continuing.
^C^CInterrupted while waiting for the program.
Give up (and stop debugging it)? (y or n) y
Notice that the `Ctrl-C' interrupts are ignored.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1031920/+subscriptions
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Qemu-devel] [Bug 1031920] Re: Linux user gdbserver does not respond to remote `Ctrl-C' interrupts
2012-08-01 20:23 [Qemu-devel] [Bug 1031920] [NEW] Linux user gdbserver does not respond to remote `Ctrl-C' interrupts Meador Inge
@ 2015-10-14 15:27 ` thierry bultel
2017-01-31 9:14 ` Thomas Huth
2017-04-02 4:17 ` Launchpad Bug Tracker
2 siblings, 0 replies; 4+ messages in thread
From: thierry bultel @ 2015-10-14 15:27 UTC (permalink / raw)
To: qemu-devel
I have encountered that issue recently, and started some analysis.
The issue is due to the fact that in qemu, gdbstub no longer reads the communication channel once
the debugged process is resumed with "cont".
Another way to say that, is that communication with gdb is only possible once the process thread execution
is re-routed in the gdb handler.
I am working on a fix.
The fix will consist in having an additional thread, launched that the internal gdbserver startup,
that will be wakeup when the debugged process is resumed.
That thread will be waiting on the communication channel for the eventually incoming CTRL-C request (0x3)
I start to have promising results but it still needs some testing.
Meanwhile, (this should likely be a separate discussion thread, but is somehow related with the named issue above) ,
I also noticed that with multithreaded
processes, a breakpoint does not suspend all the threads when it is hit.
This is a little bit annoying, and does not match the expected behaviour that is typically seen on a pure native gdb debugging
session.
Once it is ready I will post a patch to qemu mailing list
Best regards
Thierry
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1031920
Title:
Linux user gdbserver does not respond to remote `Ctrl-C' interrupts
Status in QEMU:
New
Bug description:
The bug was reproduced in a recent mainline build for ARM Linux by
starting emulation with a gdbserver:
$ qemu-arm -g 1234 a.out
and then connecting from gdb:
(gdb) target remote :1234
Remote debugging using :1234
[New Remote target]
[Switching to Remote target]
0x00008ba8 in _start ()
(gdb) b main
Breakpoint 1 at 0x8cb0: file hello.c, line 5.
(gdb) cont
Continuing.
Breakpoint 1, main (argc=1, argv=0xf6fff24c) at hello.c:5
5 int n = 0;
(gdb) l
1 #include <stdio.h>
2
3 int main (int argc, char **argv)
4 {
5 int n = 0;
6
7 for (;;) {
8 printf ("Hello, World!\n");
9 sleep (5);
10 }
(gdb) cont
Continuing.
^C^CInterrupted while waiting for the program.
Give up (and stop debugging it)? (y or n) y
Notice that the `Ctrl-C' interrupts are ignored.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1031920/+subscriptions
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Qemu-devel] [Bug 1031920] Re: Linux user gdbserver does not respond to remote `Ctrl-C' interrupts
2012-08-01 20:23 [Qemu-devel] [Bug 1031920] [NEW] Linux user gdbserver does not respond to remote `Ctrl-C' interrupts Meador Inge
2015-10-14 15:27 ` [Qemu-devel] [Bug 1031920] " thierry bultel
@ 2017-01-31 9:14 ` Thomas Huth
2017-04-02 4:17 ` Launchpad Bug Tracker
2 siblings, 0 replies; 4+ messages in thread
From: Thomas Huth @ 2017-01-31 9:14 UTC (permalink / raw)
To: qemu-devel
Has the fix mentioned in comment #1 been included in the QEMU
repository?
** Changed in: qemu
Status: New => Incomplete
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1031920
Title:
Linux user gdbserver does not respond to remote `Ctrl-C' interrupts
Status in QEMU:
Incomplete
Bug description:
The bug was reproduced in a recent mainline build for ARM Linux by
starting emulation with a gdbserver:
$ qemu-arm -g 1234 a.out
and then connecting from gdb:
(gdb) target remote :1234
Remote debugging using :1234
[New Remote target]
[Switching to Remote target]
0x00008ba8 in _start ()
(gdb) b main
Breakpoint 1 at 0x8cb0: file hello.c, line 5.
(gdb) cont
Continuing.
Breakpoint 1, main (argc=1, argv=0xf6fff24c) at hello.c:5
5 int n = 0;
(gdb) l
1 #include <stdio.h>
2
3 int main (int argc, char **argv)
4 {
5 int n = 0;
6
7 for (;;) {
8 printf ("Hello, World!\n");
9 sleep (5);
10 }
(gdb) cont
Continuing.
^C^CInterrupted while waiting for the program.
Give up (and stop debugging it)? (y or n) y
Notice that the `Ctrl-C' interrupts are ignored.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1031920/+subscriptions
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Qemu-devel] [Bug 1031920] Re: Linux user gdbserver does not respond to remote `Ctrl-C' interrupts
2012-08-01 20:23 [Qemu-devel] [Bug 1031920] [NEW] Linux user gdbserver does not respond to remote `Ctrl-C' interrupts Meador Inge
2015-10-14 15:27 ` [Qemu-devel] [Bug 1031920] " thierry bultel
2017-01-31 9:14 ` Thomas Huth
@ 2017-04-02 4:17 ` Launchpad Bug Tracker
2 siblings, 0 replies; 4+ messages in thread
From: Launchpad Bug Tracker @ 2017-04-02 4:17 UTC (permalink / raw)
To: qemu-devel
[Expired for QEMU because there has been no activity for 60 days.]
** Changed in: qemu
Status: Incomplete => Expired
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1031920
Title:
Linux user gdbserver does not respond to remote `Ctrl-C' interrupts
Status in QEMU:
Expired
Bug description:
The bug was reproduced in a recent mainline build for ARM Linux by
starting emulation with a gdbserver:
$ qemu-arm -g 1234 a.out
and then connecting from gdb:
(gdb) target remote :1234
Remote debugging using :1234
[New Remote target]
[Switching to Remote target]
0x00008ba8 in _start ()
(gdb) b main
Breakpoint 1 at 0x8cb0: file hello.c, line 5.
(gdb) cont
Continuing.
Breakpoint 1, main (argc=1, argv=0xf6fff24c) at hello.c:5
5 int n = 0;
(gdb) l
1 #include <stdio.h>
2
3 int main (int argc, char **argv)
4 {
5 int n = 0;
6
7 for (;;) {
8 printf ("Hello, World!\n");
9 sleep (5);
10 }
(gdb) cont
Continuing.
^C^CInterrupted while waiting for the program.
Give up (and stop debugging it)? (y or n) y
Notice that the `Ctrl-C' interrupts are ignored.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1031920/+subscriptions
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2017-04-02 4:37 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-08-01 20:23 [Qemu-devel] [Bug 1031920] [NEW] Linux user gdbserver does not respond to remote `Ctrl-C' interrupts Meador Inge
2015-10-14 15:27 ` [Qemu-devel] [Bug 1031920] " thierry bultel
2017-01-31 9:14 ` Thomas Huth
2017-04-02 4:17 ` Launchpad Bug Tracker
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