Re: [uml-devel] WARNING: CPU: 0 PID: 908 at include/linux/thread_info.h:128 sigsuspend+0xab/0xc0()
Hi! Am 16.11.2015 um 10:43 schrieb Vegard Nossum: > Hi, > > Starting UML like this: > > ./vmlinux rootfstype=hostfs rw ignore_console_loglevel con=xterm > init=/bin/bash > > Results in unpredictable behaviour, most of the time an xterm flashes on > my screen but the process aborts with only "Aborted" on the console > where I ran the command, sometimes the xterm remains there but frozen, > sometimes the xterm spews this warning non-stop: Hmm, is this a new regression? I bet it only happens with con=xterm, right? Thanks, //richard -- Presto, an open source distributed SQL query engine for big data, initially developed by Facebook, enables you to easily query your data on Hadoop in a more interactive manner. Teradata is also now providing full enterprise support for Presto. Download a free open source copy now. http://pubads.g.doubleclick.net/gampad/clk?id=250295911&iu=/4140 ___ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
Re: [uml-devel] WARNING: CPU: 0 PID: 908 at include/linux/thread_info.h:128 sigsuspend+0xab/0xc0()
On 11/16/2015 12:44 PM, Richard Weinberger wrote: > Am 16.11.2015 um 10:43 schrieb Vegard Nossum: >> Starting UML like this: >> >> ./vmlinux rootfstype=hostfs rw ignore_console_loglevel con=xterm >> init=/bin/bash >> >> Results in unpredictable behaviour, most of the time an xterm flashes on >> my screen but the process aborts with only "Aborted" on the console >> where I ran the command, sometimes the xterm remains there but frozen, >> sometimes the xterm spews this warning non-stop: > > Hmm, is this a new regression? > I bet it only happens with con=xterm, right? It's the first UML kernel I compile in a few years, so I don't know if it's old or new, sorry. Yes, only con=xterm triggers this. (For the record, I also couldn't con=pty or con=pts to work either, it just results in "Aborted." on the console where I ran ./vmlinux -- if I try con1=pty or con1=pts it boots normally, but there is no message in the kernel log indicating the host device that was used for the console. But this could be a PEBKAC, I only mention it in case it might be relevant. Also, normal ./vmlinux without any con*= arguments works fine, but I only get the plain stdin/stdout console.) Thanks, Vegard -- Presto, an open source distributed SQL query engine for big data, initially developed by Facebook, enables you to easily query your data on Hadoop in a more interactive manner. Teradata is also now providing full enterprise support for Presto. Download a free open source copy now. http://pubads.g.doubleclick.net/gampad/clk?id=250295911&iu=/4140 ___ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
Re: [uml-devel] WARNING: CPU: 0 PID: 908 at include/linux/thread_info.h:128 sigsuspend+0xab/0xc0()
Am 16.11.2015 um 12:49 schrieb Vegard Nossum: > On 11/16/2015 12:44 PM, Richard Weinberger wrote: >> Am 16.11.2015 um 10:43 schrieb Vegard Nossum: >>> Starting UML like this: >>> >>> ./vmlinux rootfstype=hostfs rw ignore_console_loglevel con=xterm >>> init=/bin/bash >>> >>> Results in unpredictable behaviour, most of the time an xterm flashes on >>> my screen but the process aborts with only "Aborted" on the console >>> where I ran the command, sometimes the xterm remains there but frozen, >>> sometimes the xterm spews this warning non-stop: >> >> Hmm, is this a new regression? >> I bet it only happens with con=xterm, right? > > It's the first UML kernel I compile in a few years, so I don't know if > it's old or new, sorry. > > Yes, only con=xterm triggers this. Okay, let me see. I use xterm very seldom these days. And maybe nobody else noticed. :D > (For the record, I also couldn't con=pty or con=pts to work either, it > just results in "Aborted." You can use the "earlyprintk" parameter to get more output. Thanks, //richard -- Presto, an open source distributed SQL query engine for big data, initially developed by Facebook, enables you to easily query your data on Hadoop in a more interactive manner. Teradata is also now providing full enterprise support for Presto. Download a free open source copy now. http://pubads.g.doubleclick.net/gampad/clk?id=250295911&iu=/4140 ___ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
Re: [uml-devel] WARNING: CPU: 0 PID: 908 at include/linux/thread_info.h:128 sigsuspend+0xab/0xc0()
On 16/11/15 11:53, Richard Weinberger wrote: > Am 16.11.2015 um 12:49 schrieb Vegard Nossum: >> On 11/16/2015 12:44 PM, Richard Weinberger wrote: >>> Am 16.11.2015 um 10:43 schrieb Vegard Nossum: Starting UML like this: ./vmlinux rootfstype=hostfs rw ignore_console_loglevel con=xterm init=/bin/bash Results in unpredictable behaviour, most of the time an xterm flashes on my screen but the process aborts with only "Aborted" on the console where I ran the command, sometimes the xterm remains there but frozen, sometimes the xterm spews this warning non-stop: >>> Hmm, is this a new regression? >>> I bet it only happens with con=xterm, right? >> It's the first UML kernel I compile in a few years, so I don't know if >> it's old or new, sorry. >> >> Yes, only con=xterm triggers this. > Okay, let me see. I use xterm very seldom these days. And maybe nobody else > noticed. :D ignore_console_runlevel triggers this. If you do not use it xterm console actually works fine (I use it all the time with a debian userspace). A. > >> (For the record, I also couldn't con=pty or con=pts to work either, it >> just results in "Aborted." > You can use the "earlyprintk" parameter to get more output. > > Thanks, > //richard > > -- > Presto, an open source distributed SQL query engine for big data, initially > developed by Facebook, enables you to easily query your data on Hadoop in a > more interactive manner. Teradata is also now providing full enterprise > support for Presto. Download a free open source copy now. > http://pubads.g.doubleclick.net/gampad/clk?id=250295911&iu=/4140 > ___ > User-mode-linux-devel mailing list > User-mode-linux-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel > -- Presto, an open source distributed SQL query engine for big data, initially developed by Facebook, enables you to easily query your data on Hadoop in a more interactive manner. Teradata is also now providing full enterprise support for Presto. Download a free open source copy now. http://pubads.g.doubleclick.net/gampad/clk?id=250295911&iu=/4140 ___ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
Re: [uml-devel] WARNING: CPU: 0 PID: 908 at include/linux/thread_info.h:128 sigsuspend+0xab/0xc0()
Am 16.11.2015 um 12:49 schrieb Vegard Nossum:
> On 11/16/2015 12:44 PM, Richard Weinberger wrote:
>> Am 16.11.2015 um 10:43 schrieb Vegard Nossum:
>>> Starting UML like this:
>>>
>>> ./vmlinux rootfstype=hostfs rw ignore_console_loglevel con=xterm
>>> init=/bin/bash
>>>
>>> Results in unpredictable behaviour, most of the time an xterm flashes on
>>> my screen but the process aborts with only "Aborted" on the console
>>> where I ran the command, sometimes the xterm remains there but frozen,
>>> sometimes the xterm spews this warning non-stop:
>>
>> Hmm, is this a new regression?
>> I bet it only happens with con=xterm, right?
>
> It's the first UML kernel I compile in a few years, so I don't know if
> it's old or new, sorry.
>
> Yes, only con=xterm triggers this.
/me found some odd stuff.
arch/um/drivers/chan_user.c tries to call sigsuspend() on the host side.
But sadly the kernel has also a function with the same name.
So, chan_user.c calls into the UML kernel instead of the host.
This seems to work by accident but confuses the Linux signal logic
and you trigger from time to time the WARN_ON().
>From a quick look, the kernel sigsuspend() has no users except in the same
object file. So we can mark it static and UML calls the real one.
Does the attached patch help?
I'm sure we need more work as this clearly never worked as expected. :-(
Thanks,
//richard
diff --git a/include/linux/signal.h b/include/linux/signal.h
index ab1e039..92557bb 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -239,7 +239,6 @@ extern int sigprocmask(int, sigset_t *, sigset_t *);
extern void set_current_blocked(sigset_t *);
extern void __set_current_blocked(const sigset_t *);
extern int show_unhandled_signals;
-extern int sigsuspend(sigset_t *);
struct sigaction {
#ifndef __ARCH_HAS_IRIX_SIGACTION
diff --git a/kernel/signal.c b/kernel/signal.c
index c0b01fe..f3f1f7a 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3503,7 +3503,7 @@ SYSCALL_DEFINE0(pause)
#endif
-int sigsuspend(sigset_t *set)
+static int sigsuspend(sigset_t *set)
{
current->saved_sigmask = current->blocked;
set_current_blocked(set);
--
Presto, an open source distributed SQL query engine for big data, initially
developed by Facebook, enables you to easily query your data on Hadoop in a
more interactive manner. Teradata is also now providing full enterprise
support for Presto. Download a free open source copy now.
http://pubads.g.doubleclick.net/gampad/clk?id=250295911&iu=/4140___
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Re: [uml-devel] WARNING: CPU: 0 PID: 908 at include/linux/thread_info.h:128 sigsuspend+0xab/0xc0()
On 11/16/2015 06:32 PM, Richard Weinberger wrote: > Am 16.11.2015 um 12:49 schrieb Vegard Nossum: >> On 11/16/2015 12:44 PM, Richard Weinberger wrote: >>> Am 16.11.2015 um 10:43 schrieb Vegard Nossum: Starting UML like this: ./vmlinux rootfstype=hostfs rw ignore_console_loglevel con=xterm init=/bin/bash Results in unpredictable behaviour, most of the time an xterm flashes on my screen but the process aborts with only "Aborted" on the console where I ran the command, sometimes the xterm remains there but frozen, sometimes the xterm spews this warning non-stop: >>> >>> Hmm, is this a new regression? >>> I bet it only happens with con=xterm, right? >> >> It's the first UML kernel I compile in a few years, so I don't know if >> it's old or new, sorry. >> >> Yes, only con=xterm triggers this. > > /me found some odd stuff. > > arch/um/drivers/chan_user.c tries to call sigsuspend() on the host side. > But sadly the kernel has also a function with the same name. > So, chan_user.c calls into the UML kernel instead of the host. > This seems to work by accident but confuses the Linux signal logic > and you trigger from time to time the WARN_ON(). > > From a quick look, the kernel sigsuspend() has no users except in the same > object file. So we can mark it static and UML calls the real one. > > Does the attached patch help? > I'm sure we need more work as this clearly never worked as expected. :-( Perfect, with your patch xterm works every time. (With the earlyprintk tip you gave earlier, I was also able to use con0=pts -- con0=pty doesn't seem to find any host devices, but that's probably expected.) Thanks a lot! Vegard -- Presto, an open source distributed SQL query engine for big data, initially developed by Facebook, enables you to easily query your data on Hadoop in a more interactive manner. Teradata is also now providing full enterprise support for Presto. Download a free open source copy now. http://pubads.g.doubleclick.net/gampad/clk?id=250295911&iu=/4140 ___ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
