* [Qemu-devel] [Bug 1748612] [NEW] qemu-user option -strace -D <file> doesn't work
@ 2018-02-10 12:25 mou
2018-02-12 9:49 ` [Qemu-devel] [Bug 1748612] " Peter Maydell
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: mou @ 2018-02-10 12:25 UTC (permalink / raw)
To: qemu-devel
Public bug reported:
I have been trying to access qemu -strace output from a script
The main problem was it was on stderr, the strace output was merged with my program's stderr output.
Then I tried to use the -D option, to log the output to a file.
This didn't work even if the log file was created, but it was empty.
I have looked at the source code and found the print function was not
qemu_log with -strace but gemu_log (to be clear it was GEMU NOT QEMU)
I have then replaced all gemu_log by qemu_log removed declaration of gemu_log and recompiled, it seems to works just fine right now.
removed declaration here and here:
https://github.com/qemu/qemu/blob/master/linux-user/main.c#L108
https://github.com/qemu/qemu/blob/master/linux-user/qemu.h#L203
** Affects: qemu
Importance: Undecided
Status: New
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https://bugs.launchpad.net/bugs/1748612
Title:
qemu-user option -strace -D <file> doesn't work
Status in QEMU:
New
Bug description:
I have been trying to access qemu -strace output from a script
The main problem was it was on stderr, the strace output was merged with my program's stderr output.
Then I tried to use the -D option, to log the output to a file.
This didn't work even if the log file was created, but it was empty.
I have looked at the source code and found the print function was not
qemu_log with -strace but gemu_log (to be clear it was GEMU NOT QEMU)
I have then replaced all gemu_log by qemu_log removed declaration of gemu_log and recompiled, it seems to works just fine right now.
removed declaration here and here:
https://github.com/qemu/qemu/blob/master/linux-user/main.c#L108
https://github.com/qemu/qemu/blob/master/linux-user/qemu.h#L203
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1748612/+subscriptions
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Qemu-devel] [Bug 1748612] Re: qemu-user option -strace -D <file> doesn't work
2018-02-10 12:25 [Qemu-devel] [Bug 1748612] [NEW] qemu-user option -strace -D <file> doesn't work mou
@ 2018-02-12 9:49 ` Peter Maydell
2018-02-12 10:04 ` mou
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Peter Maydell @ 2018-02-12 9:49 UTC (permalink / raw)
To: qemu-devel
This is intentional, more or less. The -D logfile is for the debug logs
enabled with -d, not for strace. I think if we wanted to support
redirecting strace output to a file we might need to have an extra
argument, to avoid breaking existing users.
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https://bugs.launchpad.net/bugs/1748612
Title:
qemu-user option -strace -D <file> doesn't work
Status in QEMU:
New
Bug description:
I have been trying to access qemu -strace output from a script
The main problem was it was on stderr, the strace output was merged with my program's stderr output.
Then I tried to use the -D option, to log the output to a file.
This didn't work even if the log file was created, but it was empty.
I have looked at the source code and found the print function was not
qemu_log with -strace but gemu_log (to be clear it was GEMU NOT QEMU)
I have then replaced all gemu_log by qemu_log removed declaration of gemu_log and recompiled, it seems to works just fine right now.
removed declaration here and here:
https://github.com/qemu/qemu/blob/master/linux-user/main.c#L108
https://github.com/qemu/qemu/blob/master/linux-user/qemu.h#L203
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1748612/+subscriptions
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Qemu-devel] [Bug 1748612] Re: qemu-user option -strace -D <file> doesn't work
2018-02-10 12:25 [Qemu-devel] [Bug 1748612] [NEW] qemu-user option -strace -D <file> doesn't work mou
2018-02-12 9:49 ` [Qemu-devel] [Bug 1748612] " Peter Maydell
@ 2018-02-12 10:04 ` mou
2018-02-12 10:38 ` Peter Maydell
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: mou @ 2018-02-12 10:04 UTC (permalink / raw)
To: qemu-devel
If this is not for strace, then why when I launch qemu as subprocess (example: from a python script)
with option -strace -D <file> it creates a log file called <file>-strace? Seems like a bug to me.
Anyway, I understand you don't want to break the current behavior, is there any chance this gets added in the near future?
--
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1748612
Title:
qemu-user option -strace -D <file> doesn't work
Status in QEMU:
New
Bug description:
I have been trying to access qemu -strace output from a script
The main problem was it was on stderr, the strace output was merged with my program's stderr output.
Then I tried to use the -D option, to log the output to a file.
This didn't work even if the log file was created, but it was empty.
I have looked at the source code and found the print function was not
qemu_log with -strace but gemu_log (to be clear it was GEMU NOT QEMU)
I have then replaced all gemu_log by qemu_log removed declaration of gemu_log and recompiled, it seems to works just fine right now.
removed declaration here and here:
https://github.com/qemu/qemu/blob/master/linux-user/main.c#L108
https://github.com/qemu/qemu/blob/master/linux-user/qemu.h#L203
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1748612/+subscriptions
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Qemu-devel] [Bug 1748612] Re: qemu-user option -strace -D <file> doesn't work
2018-02-10 12:25 [Qemu-devel] [Bug 1748612] [NEW] qemu-user option -strace -D <file> doesn't work mou
2018-02-12 9:49 ` [Qemu-devel] [Bug 1748612] " Peter Maydell
2018-02-12 10:04 ` mou
@ 2018-02-12 10:38 ` Peter Maydell
2018-02-12 10:48 ` mou
2020-11-23 9:56 ` Thomas Huth
4 siblings, 0 replies; 6+ messages in thread
From: Peter Maydell @ 2018-02-12 10:38 UTC (permalink / raw)
To: qemu-devel
If you use -D <file> it will create a file named <file>, which will
contain any logs created via the qemu_log subsystem (which might be
nothing at all, depending on what the guest does). I don't know where
the "-strace" part would come from unless you specified it as part of
the filename.
--
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1748612
Title:
qemu-user option -strace -D <file> doesn't work
Status in QEMU:
New
Bug description:
I have been trying to access qemu -strace output from a script
The main problem was it was on stderr, the strace output was merged with my program's stderr output.
Then I tried to use the -D option, to log the output to a file.
This didn't work even if the log file was created, but it was empty.
I have looked at the source code and found the print function was not
qemu_log with -strace but gemu_log (to be clear it was GEMU NOT QEMU)
I have then replaced all gemu_log by qemu_log removed declaration of gemu_log and recompiled, it seems to works just fine right now.
removed declaration here and here:
https://github.com/qemu/qemu/blob/master/linux-user/main.c#L108
https://github.com/qemu/qemu/blob/master/linux-user/qemu.h#L203
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1748612/+subscriptions
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Qemu-devel] [Bug 1748612] Re: qemu-user option -strace -D <file> doesn't work
2018-02-10 12:25 [Qemu-devel] [Bug 1748612] [NEW] qemu-user option -strace -D <file> doesn't work mou
` (2 preceding siblings ...)
2018-02-12 10:38 ` Peter Maydell
@ 2018-02-12 10:48 ` mou
2020-11-23 9:56 ` Thomas Huth
4 siblings, 0 replies; 6+ messages in thread
From: mou @ 2018-02-12 10:48 UTC (permalink / raw)
To: qemu-devel
I will check that again, pretty sure I saw that.
Anyway any chance there is an option/fix for that?
Today it is impossible to differentiate strace output with program's stderr output, and it is causing trouble while used in scripts.
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1748612
Title:
qemu-user option -strace -D <file> doesn't work
Status in QEMU:
New
Bug description:
I have been trying to access qemu -strace output from a script
The main problem was it was on stderr, the strace output was merged with my program's stderr output.
Then I tried to use the -D option, to log the output to a file.
This didn't work even if the log file was created, but it was empty.
I have looked at the source code and found the print function was not
qemu_log with -strace but gemu_log (to be clear it was GEMU NOT QEMU)
I have then replaced all gemu_log by qemu_log removed declaration of gemu_log and recompiled, it seems to works just fine right now.
removed declaration here and here:
https://github.com/qemu/qemu/blob/master/linux-user/main.c#L108
https://github.com/qemu/qemu/blob/master/linux-user/qemu.h#L203
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1748612/+subscriptions
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug 1748612] Re: qemu-user option -strace -D <file> doesn't work
2018-02-10 12:25 [Qemu-devel] [Bug 1748612] [NEW] qemu-user option -strace -D <file> doesn't work mou
` (3 preceding siblings ...)
2018-02-12 10:48 ` mou
@ 2020-11-23 9:56 ` Thomas Huth
4 siblings, 0 replies; 6+ messages in thread
From: Thomas Huth @ 2020-11-23 9:56 UTC (permalink / raw)
To: qemu-devel
I think this has been fixed here:
https://git.qemu.org/?p=qemu.git;a=commitdiff;h=4b25a50674de41e72f6b3003
** Changed in: qemu
Status: New => Fix Released
--
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1748612
Title:
qemu-user option -strace -D <file> doesn't work
Status in QEMU:
Fix Released
Bug description:
I have been trying to access qemu -strace output from a script
The main problem was it was on stderr, the strace output was merged with my program's stderr output.
Then I tried to use the -D option, to log the output to a file.
This didn't work even if the log file was created, but it was empty.
I have looked at the source code and found the print function was not
qemu_log with -strace but gemu_log (to be clear it was GEMU NOT QEMU)
I have then replaced all gemu_log by qemu_log removed declaration of gemu_log and recompiled, it seems to works just fine right now.
removed declaration here and here:
https://github.com/qemu/qemu/blob/master/linux-user/main.c#L108
https://github.com/qemu/qemu/blob/master/linux-user/qemu.h#L203
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1748612/+subscriptions
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-11-23 10:12 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-02-10 12:25 [Qemu-devel] [Bug 1748612] [NEW] qemu-user option -strace -D <file> doesn't work mou
2018-02-12 9:49 ` [Qemu-devel] [Bug 1748612] " Peter Maydell
2018-02-12 10:04 ` mou
2018-02-12 10:38 ` Peter Maydell
2018-02-12 10:48 ` mou
2020-11-23 9:56 ` Thomas Huth
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