[PATCH] parisc: fix kernel crash when unwinding a userspace process

[PATCH] parisc: fix kernel crash when unwinding a userspace process

[Helge Deller]

Any user on existing parisc 32- and 64bit-kernels can easily crash
the kernel and as such enforce a DSO.
A simple testcase is available here: 
	http://gsyprf10.external.hp.com/~deller/crash.tgz

The problem is introduced by the fact, that the handle_interruption()
crash handler calls the show_regs() function, which in turn tries
to unwind the stack by calling parisc_show_stack().
Since the stack contains userspace addresses, a try to unwind 
the stack is dangerous and useless and leads to the crash.

The fix is trivial: For userspace processes
a) avoid to unwind the stack, and
b) avoid to resolve userspace addresses to kernel symbol names.

While touching this code, I converted print_symbol() to %pS 
printk formats and made parisc_show_stack() static.

An initial patch for this was written by Kyle McMartin back in August:
http://marc.info/?l=linux-parisc&m=121805168830283&w=2

Compile and run-tested with a 64bit parisc kernel.
Patches for -stable series will follow shortly.

Signed-off-by: Helge Deller <deller@gmx.de>


diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index 675f1d0..acea2dc 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -24,7 +24,6 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/console.h>
-#include <linux/kallsyms.h>
 #include <linux/bug.h>
 
 #include <asm/assembly.h>
@@ -51,7 +50,7 @@
 DEFINE_SPINLOCK(pa_dbit_lock);
 #endif
 
-void parisc_show_stack(struct task_struct *t, unsigned long *sp,
+static void parisc_show_stack(struct task_struct *task, unsigned long *sp,
 	struct pt_regs *regs);
 
 static int printbinary(char *buf, unsigned long x, int nbits)
@@ -121,18 +120,19 @@ static void print_fr(char *level, struct pt_regs *regs)
 
 void show_regs(struct pt_regs *regs)
 {
-	int i;
+	int i, user;
 	char *level;
 	unsigned long cr30, cr31;
 
-	level = user_mode(regs) ? KERN_DEBUG : KERN_CRIT;
+	user = user_mode(regs);
+	level = user ? KERN_DEBUG : KERN_CRIT;
 
 	print_gr(level, regs);
 
 	for (i = 0; i < 8; i += 4)
 		PRINTREGS(level, regs->sr, "sr", RFMT, i);
 
-	if (user_mode(regs))
+	if (user)
 		print_fr(level, regs);
 
 	cr30 = mfctl(30);
@@ -145,14 +145,14 @@ void show_regs(struct pt_regs *regs)
 	printk("%s CPU: %8d   CR30: " RFMT " CR31: " RFMT "\n",
 	       level, current_thread_info()->cpu, cr30, cr31);
 	printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28);
-	printk(level);
-	print_symbol(" IAOQ[0]: %s\n", regs->iaoq[0]);
-	printk(level);
-	print_symbol(" IAOQ[1]: %s\n", regs->iaoq[1]);
-	printk(level);
-	print_symbol(" RP(r2): %s\n", regs->gr[2]);
-
-	parisc_show_stack(current, NULL, regs);
+
+	if (!user) {
+		printk("%s IAOQ[0]: %pS\n", level, (void *) regs->iaoq[0]);
+		printk("%s IAOQ[1]: %pS\n", level, (void *) regs->iaoq[1]);
+		printk("%s RP(r2): %pS\n", level, (void *) regs->gr[2]);
+
+		parisc_show_stack(current, NULL, regs);
+	}
 }
 
 
@@ -173,20 +173,15 @@ static void do_show_stack(struct unwind_frame_info *info)
 			break;
 
 		if (__kernel_text_address(info->ip)) {
-			printk("%s [<" RFMT ">] ", (i&0x3)==1 ? KERN_CRIT : "", info->ip);
-#ifdef CONFIG_KALLSYMS
-			print_symbol("%s\n", info->ip);
-#else
-			if ((i & 0x03) == 0)
-				printk("\n");
-#endif
+			printk(KERN_CRIT " [<" RFMT ">] %pS\n",
+				info->ip, (void *) info->ip);
 			i++;
 		}
 	}
-	printk("\n");
+	printk(KERN_CRIT "\n");
 }
 
-void parisc_show_stack(struct task_struct *task, unsigned long *sp,
+static void parisc_show_stack(struct task_struct *task, unsigned long *sp,
 	struct pt_regs *regs)
 {
 	struct unwind_frame_info info;

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process

[Randolph Chung]

Helge Deller wrote:
> Any user on existing parisc 32- and 64bit-kernels can easily crash
> the kernel and as such enforce a DSO.
> A simple testcase is available here: 
> 	http://gsyprf10.external.hp.com/~deller/crash.tgz
> 
> The problem is introduced by the fact, that the handle_interruption()
> crash handler calls the show_regs() function, which in turn tries
> to unwind the stack by calling parisc_show_stack().
> Since the stack contains userspace addresses, a try to unwind 
> the stack is dangerous and useless and leads to the crash.

Helge,

I think this is ok, but can you preserve the printing of IAOQ/RP even 
for user processes?

randolph

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process

[Helge Deller]

Randolph Chung wrote:
> Helge Deller wrote:
>> Any user on existing parisc 32- and 64bit-kernels can easily crash
>> the kernel and as such enforce a DSO.
>> A simple testcase is available here: 
>>     http://gsyprf10.external.hp.com/~deller/crash.tgz
>>
>> The problem is introduced by the fact, that the handle_interruption()
>> crash handler calls the show_regs() function, which in turn tries
>> to unwind the stack by calling parisc_show_stack().
>> Since the stack contains userspace addresses, a try to unwind the 
>> stack is dangerous and useless and leads to the crash.
> 
> Helge,
> 
> I think this is ok, but can you preserve the printing of IAOQ/RP even 
> for user processes?

Thanks Randolph,

You are probably right. It's better to stay consistent for debugging and 
you'll see the important registers at once.
I'll respin a new patch.

Helge

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process (v2)

[Helge Deller]

Any user on existing parisc 32- and 64bit-kernels can easily crash
the kernel and as such enforce a DSO.
A simple testcase is available here: 
        http://gsyprf10.external.hp.com/~deller/crash.tgz

The problem is introduced by the fact, that the handle_interruption()
crash handler calls the show_regs() function, which in turn tries
to unwind the stack by calling parisc_show_stack().
Since the stack contains userspace addresses, a try to unwind 
the stack is dangerous and useless and leads to the crash.

The fix is trivial: For userspace processes
a) avoid to unwind the stack, and
b) avoid to resolve userspace addresses to kernel symbol names.

While touching this code, I converted print_symbol() to %pS 
printk formats and made parisc_show_stack() static.

An initial patch for this was written by Kyle McMartin back in August:
http://marc.info/?l=linux-parisc&m=121805168830283&w=2

Compile and run-tested with a 64bit parisc kernel.
Patches for -stable series will follow shortly.

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index 675f1d0..4c771cd 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -24,7 +24,6 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/console.h>
-#include <linux/kallsyms.h>
 #include <linux/bug.h>
 
 #include <asm/assembly.h>
@@ -51,7 +50,7 @@
 DEFINE_SPINLOCK(pa_dbit_lock);
 #endif
 
-void parisc_show_stack(struct task_struct *t, unsigned long *sp,
+static void parisc_show_stack(struct task_struct *task, unsigned long *sp,
 	struct pt_regs *regs);
 
 static int printbinary(char *buf, unsigned long x, int nbits)
@@ -121,18 +120,19 @@ static void print_fr(char *level, struct pt_regs *regs)
 
 void show_regs(struct pt_regs *regs)
 {
-	int i;
+	int i, user;
 	char *level;
 	unsigned long cr30, cr31;
 
-	level = user_mode(regs) ? KERN_DEBUG : KERN_CRIT;
+	user = user_mode(regs);
+	level = user ? KERN_DEBUG : KERN_CRIT;
 
 	print_gr(level, regs);
 
 	for (i = 0; i < 8; i += 4)
 		PRINTREGS(level, regs->sr, "sr", RFMT, i);
 
-	if (user_mode(regs))
+	if (user)
 		print_fr(level, regs);
 
 	cr30 = mfctl(30);
@@ -145,14 +145,18 @@ void show_regs(struct pt_regs *regs)
 	printk("%s CPU: %8d   CR30: " RFMT " CR31: " RFMT "\n",
 	       level, current_thread_info()->cpu, cr30, cr31);
 	printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28);
-	printk(level);
-	print_symbol(" IAOQ[0]: %s\n", regs->iaoq[0]);
-	printk(level);
-	print_symbol(" IAOQ[1]: %s\n", regs->iaoq[1]);
-	printk(level);
-	print_symbol(" RP(r2): %s\n", regs->gr[2]);
-
-	parisc_show_stack(current, NULL, regs);
+
+	if (user) {
+		printk("%s IAOQ[0]: " RFMT "\n", level, regs->iaoq[0]);
+		printk("%s IAOQ[1]: " RFMT "\n", level, regs->iaoq[1]);
+		printk("%s RP(r2): " RFMT "\n", level, regs->gr[2]);
+	} else {
+		printk("%s IAOQ[0]: %pS\n", level, (void *) regs->iaoq[0]);
+		printk("%s IAOQ[1]: %pS\n", level, (void *) regs->iaoq[1]);
+		printk("%s RP(r2): %pS\n", level, (void *) regs->gr[2]);
+
+		parisc_show_stack(current, NULL, regs);
+	}
 }
 
 
@@ -173,20 +177,15 @@ static void do_show_stack(struct unwind_frame_info *info)
 			break;
 
 		if (__kernel_text_address(info->ip)) {
-			printk("%s [<" RFMT ">] ", (i&0x3)==1 ? KERN_CRIT : "", info->ip);
-#ifdef CONFIG_KALLSYMS
-			print_symbol("%s\n", info->ip);
-#else
-			if ((i & 0x03) == 0)
-				printk("\n");
-#endif
+			printk(KERN_CRIT " [<" RFMT ">] %pS\n",
+				info->ip, (void *) info->ip);
 			i++;
 		}
 	}
-	printk("\n");
+	printk(KERN_CRIT "\n");
 }
 
-void parisc_show_stack(struct task_struct *task, unsigned long *sp,
+static void parisc_show_stack(struct task_struct *task, unsigned long *sp,
 	struct pt_regs *regs)
 {
 	struct unwind_frame_info info;

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process (v2)

[Andrew Morton]

On Fri, 21 Nov 2008 15:16:50 +0100
Helge Deller <deller@gmx.de> wrote:

> Any user on existing parisc 32- and 64bit-kernels can easily crash
> the kernel and as such enforce a DSO.
> A simple testcase is available here: 
>         http://gsyprf10.external.hp.com/~deller/crash.tgz
> 
> The problem is introduced by the fact, that the handle_interruption()
> crash handler calls the show_regs() function, which in turn tries
> to unwind the stack by calling parisc_show_stack().
> Since the stack contains userspace addresses, a try to unwind 
> the stack is dangerous and useless and leads to the crash.
> 
> The fix is trivial: For userspace processes
> a) avoid to unwind the stack, and
> b) avoid to resolve userspace addresses to kernel symbol names.
> 
> While touching this code, I converted print_symbol() to %pS 
> printk formats and made parisc_show_stack() static.
> 
> An initial patch for this was written by Kyle McMartin back in August:
> http://marc.info/?l=linux-parisc&m=121805168830283&w=2
> 
> Compile and run-tested with a 64bit parisc kernel.

Why has a fix for such a severe bug been floating around unmerged for
such a long time?

> Patches for -stable series will follow shortly.

That shouldn't be needed - I'll cc stable on my copy and the stable
maintainers should see that and pick it up.  The patch applies cleanly
all the way back to 2.6.25.

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process (v2)

[Helge Deller]

Andrew Morton wrote:
> On Fri, 21 Nov 2008 15:16:50 +0100
> Helge Deller <deller@gmx.de> wrote:
> 
>> Any user on existing parisc 32- and 64bit-kernels can easily crash
>> the kernel and as such enforce a DSO.
>> A simple testcase is available here: 
>>         http://gsyprf10.external.hp.com/~deller/crash.tgz
>>
>> The problem is introduced by the fact, that the handle_interruption()
>> crash handler calls the show_regs() function, which in turn tries
>> to unwind the stack by calling parisc_show_stack().
>> Since the stack contains userspace addresses, a try to unwind 
>> the stack is dangerous and useless and leads to the crash.
>>
>> The fix is trivial: For userspace processes
>> a) avoid to unwind the stack, and
>> b) avoid to resolve userspace addresses to kernel symbol names.
>>
>> While touching this code, I converted print_symbol() to %pS 
>> printk formats and made parisc_show_stack() static.
>>
>> An initial patch for this was written by Kyle McMartin back in August:
>> http://marc.info/?l=linux-parisc&m=121805168830283&w=2
>>
>> Compile and run-tested with a 64bit parisc kernel.
> 
> Why has a fix for such a severe bug been floating around unmerged for
> such a long time?

I've tried to push it upstream a few times...

>> Patches for -stable series will follow shortly.
> 
> That shouldn't be needed - I'll cc stable on my copy and the stable
> maintainers should see that and pick it up.  The patch applies cleanly
> all the way back to 2.6.25.

Although it may apply to the older stable kernels, I'm currently not 
sure if this will work then.
We added the fixes for PA for the '%pS' vsprintf format pretty late. 
This is probably then a patch which needs backporting to stable as well 
(if it didn't happened yet):
	commit deac93df26b20cf8438339b5935b5f5643bc30c9
	Author: James Bottomley <James.Bottomley@HansenPartnership.com>
	Date:   Wed Sep 3 20:43:36 2008 -0500
	lib: Correct printk %pF to work on all architectures

Alternatively, I could write a little more simple patch, which is what I 
  intended initially.

Thanks a lot Andrew!
Helge

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process (v2)

[Andrew Morton]

On Fri, 21 Nov 2008 23:00:06 +0100
Helge Deller <deller@gmx.de> wrote:

> Andrew Morton wrote:
> > On Fri, 21 Nov 2008 15:16:50 +0100
> > Helge Deller <deller@gmx.de> wrote:
> > 
> >> Any user on existing parisc 32- and 64bit-kernels can easily crash
> >> the kernel and as such enforce a DSO.
> >> A simple testcase is available here: 
> >>         http://gsyprf10.external.hp.com/~deller/crash.tgz
> >>
> >> The problem is introduced by the fact, that the handle_interruption()
> >> crash handler calls the show_regs() function, which in turn tries
> >> to unwind the stack by calling parisc_show_stack().
> >> Since the stack contains userspace addresses, a try to unwind 
> >> the stack is dangerous and useless and leads to the crash.
> >>
> >> The fix is trivial: For userspace processes
> >> a) avoid to unwind the stack, and
> >> b) avoid to resolve userspace addresses to kernel symbol names.
> >>
> >> While touching this code, I converted print_symbol() to %pS 
> >> printk formats and made parisc_show_stack() static.
> >>
> >> An initial patch for this was written by Kyle McMartin back in August:
> >> http://marc.info/?l=linux-parisc&m=121805168830283&w=2
> >>
> >> Compile and run-tested with a 64bit parisc kernel.
> > 
> > Why has a fix for such a severe bug been floating around unmerged for
> > such a long time?
> 
> I've tried to push it upstream a few times...

OK, well I'll merge it next week unless someone stops me.

> >> Patches for -stable series will follow shortly.
> > 
> > That shouldn't be needed - I'll cc stable on my copy and the stable
> > maintainers should see that and pick it up.  The patch applies cleanly
> > all the way back to 2.6.25.
> 
> Although it may apply to the older stable kernels, I'm currently not 
> sure if this will work then.
> We added the fixes for PA for the '%pS' vsprintf format pretty late. 
> This is probably then a patch which needs backporting to stable as well 
> (if it didn't happened yet):
> 	commit deac93df26b20cf8438339b5935b5f5643bc30c9
> 	Author: James Bottomley <James.Bottomley@HansenPartnership.com>
> 	Date:   Wed Sep 3 20:43:36 2008 -0500
> 	lib: Correct printk %pF to work on all architectures

Oh, OK.  I'll update the stable tag in the patch appropriately.

> Alternatively, I could write a little more simple patch, which is what I 
>   intended initially.

I'd suggest that you send that patch to stable@kernel.org in reply to
this one when you see it get dropped from -mm.

Unless someone stops me ;)

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process (v2)

[Grant Grundler]

On Fri, Nov 21, 2008 at 02:20:13PM -0800, Andrew Morton wrote:
...
> > > Why has a fix for such a severe bug been floating around unmerged for
> > > such a long time?

Three people are listed for parisc-linux in MAINTAINERS.
My understanding was Kyle would integrate and push patches.
Willy and I would help by reviewing code, testing and misc crap.

I asked if I should ACK parisc specific patches and was told in general
I didn't need to. I will start sending "Reviewed By:" when I feel
I understand what a patch fixes and that it's correct (even if not perfect).

> > I've tried to push it upstream a few times...
> 
> OK, well I'll merge it next week unless someone stops me.

I won't stop you. :)
Based on this posting:
    http://marc.info/?l=linux-parisc&m=122726233324164&w=2

you can add:
   Review-by: Randolph Chung <randolph@tausq.org>

I trust Randolph - he used to have commit access to the parisc-linux.org
CVS tree when we still used one.

And Helge has been great about fixing stuff - much better than the three
listed maintainers lately.
Kyle, willy, any objection to adding Helge to the MAINTAINERS list
for PARISC port?
I'd rather allow Helge to make a few small mistakes occasionally rather
than watch his parisc specific patches fall on the floor.

thanks,
grant

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process (v2)

[Matthew Wilcox]

On Fri, Nov 21, 2008 at 10:53:01PM -0700, Grant Grundler wrote:
> And Helge has been great about fixing stuff - much better than the three
> listed maintainers lately.
> Kyle, willy, any objection to adding Helge to the MAINTAINERS list
> for PARISC port?
> I'd rather allow Helge to make a few small mistakes occasionally rather
> than watch his parisc specific patches fall on the floor.

No objection from me.  I think it's time to remove me from MAINTAINERS
as it's probably been six months since I last turned on any of my parisc
machines.

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process (v2)

[Grant Grundler]

On Sat, Nov 22, 2008 at 05:22:09AM -0700, Matthew Wilcox wrote:
> On Fri, Nov 21, 2008 at 10:53:01PM -0700, Grant Grundler wrote:
> > And Helge has been great about fixing stuff - much better than the three
> > listed maintainers lately.
> > Kyle, willy, any objection to adding Helge to the MAINTAINERS list
> > for PARISC port?
> > I'd rather allow Helge to make a few small mistakes occasionally rather
> > than watch his parisc specific patches fall on the floor.
> 
> No objection from me.  I think it's time to remove me from MAINTAINERS
> as it's probably been six months since I last turned on any of my parisc
> machines.

Thanks!  We have quorum.
Andrew can you please apply this and send to linus?
Or should I start acting like a maintainer and send it myself? :)

Willy, I'm not removing you from Cupertino test ring LDAP or any other
privileges unless you ask me to. Just note I appreciate all of your past
(and future) help with the port and you are always welcome in Mountain View.

thanks,
grant

Signed-off-By: Grant Grundler <grundler@parisc-linux.org>
Reviewed-by: Matthew Wilcox <matthew@wil.cx>

diff --git a/MAINTAINERS b/MAINTAINERS
index 618c1ef..5b5034c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3294,8 +3294,8 @@ S:	Maintained
 PARISC ARCHITECTURE
 P:	Kyle McMartin
 M:	kyle@mcmartin.ca
-P:	Matthew Wilcox
-M:	matthew@wil.cx
+P:	Helge Deller
+M:	deller@gmx.de
 P:	Grant Grundler
 M:	grundler@parisc-linux.org
 L:	linux-parisc@vger.kernel.org

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process (v2)

[Helge Deller]

Grant Grundler wrote:
> On Sat, Nov 22, 2008 at 05:22:09AM -0700, Matthew Wilcox wrote:
>> On Fri, Nov 21, 2008 at 10:53:01PM -0700, Grant Grundler wrote:
>>> And Helge has been great about fixing stuff - much better than the three
>>> listed maintainers lately.
>>> Kyle, willy, any objection to adding Helge to the MAINTAINERS list
>>> for PARISC port?
>>> I'd rather allow Helge to make a few small mistakes occasionally rather
>>> than watch his parisc specific patches fall on the floor.
>> No objection from me.  I think it's time to remove me from MAINTAINERS
>> as it's probably been six months since I last turned on any of my parisc
>> machines.
> 
> Thanks!  We have quorum.
> Andrew can you please apply this and send to linus?
> Or should I start acting like a maintainer and send it myself? :)
> 
> Willy, I'm not removing you from Cupertino test ring LDAP or any other
> privileges unless you ask me to. Just note I appreciate all of your past
> (and future) help with the port and you are always welcome in Mountain View.
> 
> thanks,
> grant
> 
> Signed-off-By: Grant Grundler <grundler@parisc-linux.org>
> Reviewed-by: Matthew Wilcox <matthew@wil.cx>

Acked-by: Helge Deller <deller@gmx.de>

> diff --git a/MAINTAINERS b/MAINTAINERS
> index 618c1ef..5b5034c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3294,8 +3294,8 @@ S:	Maintained
>  PARISC ARCHITECTURE
>  P:	Kyle McMartin
>  M:	kyle@mcmartin.ca
> -P:	Matthew Wilcox
> -M:	matthew@wil.cx
> +P:	Helge Deller
> +M:	deller@gmx.de
>  P:	Grant Grundler
>  M:	grundler@parisc-linux.org
>  L:	linux-parisc@vger.kernel.org
> 

Re: [PATCH] 2.6.28-rc6 update parisc MAINTAINERS

[Grant Grundler]

On Sat, Nov 22, 2008 at 11:01:52AM -0700, Grant Grundler wrote:
> On Sat, Nov 22, 2008 at 05:22:09AM -0700, Matthew Wilcox wrote:
> > On Fri, Nov 21, 2008 at 10:53:01PM -0700, Grant Grundler wrote:
> > > And Helge has been great about fixing stuff - much better than the three
> > > listed maintainers lately.
> > > Kyle, willy, any objection to adding Helge to the MAINTAINERS list
> > > for PARISC port?
> > > I'd rather allow Helge to make a few small mistakes occasionally rather
> > > than watch his parisc specific patches fall on the floor.
> > 
> > No objection from me.  I think it's time to remove me from MAINTAINERS
> > as it's probably been six months since I last turned on any of my parisc
> > machines.
> 
> Thanks!  We have quorum.
> Andrew can you please apply this and send to linus?
> Or should I start acting like a maintainer and send it myself? :)
> 
> Willy, I'm not removing you from Cupertino test ring LDAP or any other
> privileges unless you ask me to. Just note I appreciate all of your past
> (and future) help with the port and you are always welcome in Mountain View.

Andrew,

Updated version of this patch: I'm removing my own name as well for some of
the same reasons as willy. I'll continue to review patches for linux-parisc,
maintaining parisc/ia64 systems for gcc/kernel developer access, and testing
kernels on parisc occasionally (working on autotest.kernel.org to get
that more consistent and easier.)

thanks,
grant

Signed-off-By: Grant Grundler <grundler@parisc-linux.org>
Reviewed-by: Matthew Wilcox <matthew@wil.cx>
Acked-by: Helge Deller <deller@gmx.de>


diff --git a/MAINTAINERS b/MAINTAINERS
index 618c1ef..56e519a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3294,10 +3294,8 @@ S:	Maintained
 PARISC ARCHITECTURE
 P:	Kyle McMartin
 M:	kyle@mcmartin.ca
-P:	Matthew Wilcox
-M:	matthew@wil.cx
-P:	Grant Grundler
-M:	grundler@parisc-linux.org
+P:	Helge Deller
+M:	deller@gmx.de
 L:	linux-parisc@vger.kernel.org
 W:	http://www.parisc-linux.org/
 T:	git kernel.org:/pub/scm/linux/kernel/git/kyle/parisc-2.6.git

Re: [PATCH] 2.6.28-rc6 update parisc MAINTAINERS

[Helge Deller]

Grant Grundler wrote:
> On Sat, Nov 22, 2008 at 11:01:52AM -0700, Grant Grundler wrote:
>> On Sat, Nov 22, 2008 at 05:22:09AM -0700, Matthew Wilcox wrote:
>>> On Fri, Nov 21, 2008 at 10:53:01PM -0700, Grant Grundler wrote:
>>>> And Helge has been great about fixing stuff - much better than the three
>>>> listed maintainers lately.
>>>> Kyle, willy, any objection to adding Helge to the MAINTAINERS list
>>>> for PARISC port?
>>>> I'd rather allow Helge to make a few small mistakes occasionally rather
>>>> than watch his parisc specific patches fall on the floor.
>>> No objection from me.  I think it's time to remove me from MAINTAINERS
>>> as it's probably been six months since I last turned on any of my parisc
>>> machines.
>> Thanks!  We have quorum.
>> Andrew can you please apply this and send to linus?
>> Or should I start acting like a maintainer and send it myself? :)
>>
>> Willy, I'm not removing you from Cupertino test ring LDAP or any other
>> privileges unless you ask me to. Just note I appreciate all of your past
>> (and future) help with the port and you are always welcome in Mountain View.
> 
> Andrew,
> 
> Updated version of this patch: I'm removing my own name as well for some of
> the same reasons as willy. 

Grant, even if you are currently only occasionally fixing bugs or 
reviewing patches, I think it would still be valuable to keep you listed 
here as one of the parisc maintainers.

Helge

Re: [PATCH] 2.6.28-rc6 update parisc MAINTAINERS

[Grant Grundler]

On Mon, Dec 01, 2008 at 04:59:02PM +0100, Helge Deller wrote:
> Grant Grundler wrote:
...
>> Updated version of this patch: I'm removing my own name as well for some 
>> of the same reasons as willy. 
>
> Grant, even if you are currently only occasionally fixing bugs or reviewing 
> patches, I think it would still be valuable to keep you listed here as one 
> of the parisc maintainers.

Helge,
Thanks!

But it sounds a bit biased coming from you given I just nominated
you to be listed as maintainer. :)

"occasionally fixing bugs" is generous with respect to parisc-linux.
I've prevented a few bugs this year (code review) and substantially helped
the Intel IOMMU driver maintainer code (on linux-pci). But those aren't
reasons to be listed as parisc-linux maintainer.

I will continue to review parisc-linux patches and occasionally work
on "porting" autotest.kernel.org to parisc-linux. I think that would
help the port to avoid regressions. I'm just not able (time and ability)
to fix the latest major issue which we've been guessing is cache
coherency related.

thanks,
grant

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process (v2)

[Kyle McMartin]

On Fri, Nov 21, 2008 at 10:53:01PM -0700, Grant Grundler wrote:
> And Helge has been great about fixing stuff - much better than the three
> listed maintainers lately.

You have an awful lot of nerve saying this, considering.

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process (v2)

[Grant Grundler]

On Tue, Nov 25, 2008 at 12:20:00PM -0500, Kyle McMartin wrote:
> On Fri, Nov 21, 2008 at 10:53:01PM -0700, Grant Grundler wrote:
> > And Helge has been great about fixing stuff - much better than the three
> > listed maintainers lately.
> 
> You have an awful lot of nerve saying this, considering.

Kyle,
For parisc specific files, I've seen more patches from Helge on
linux-parisc than anyone else. That's all I meant.  I know I've
contributed zero parisc patches in a long time.
I'm not out to offend anyone or pick on you specifically.

I routinely review other people's parisc patches, occasionally try to
narrow down the latest b0rkage, and will continue with the care and
feeding of the public access machines in Cupertino. The "code review"
is the only reason I feel like I should continue as a listed maintainer.

thanks,
grant

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process (v2)

[Kyle McMartin]

On Tue, Nov 25, 2008 at 07:47:56PM -0700, Grant Grundler wrote:
> On Tue, Nov 25, 2008 at 12:20:00PM -0500, Kyle McMartin wrote:
> > On Fri, Nov 21, 2008 at 10:53:01PM -0700, Grant Grundler wrote:
> > > And Helge has been great about fixing stuff - much better than the three
> > > listed maintainers lately.
> > 
> > You have an awful lot of nerve saying this, considering.
> 
> Kyle,
> For parisc specific files, I've seen more patches from Helge on
> linux-parisc than anyone else. That's all I meant.  I know I've
> contributed zero parisc patches in a long time.
> I'm not out to offend anyone or pick on you specifically.
> 
> I routinely review other people's parisc patches, occasionally try to
> narrow down the latest b0rkage, and will continue with the care and
> feeding of the public access machines in Cupertino. The "code review"
> is the only reason I feel like I should continue as a listed maintainer.
> 

Possibly because I don't send my own to the mailing list unless I feel
they need review?

Seriously, I *am* offended and I believe I have every right to be.

Re: [PATCH] parisc: fix kernel crash when unwinding a userspace process

[Kyle McMartin]

On Thu, Nov 20, 2008 at 10:58:56PM +0100, Helge Deller wrote:
> Any user on existing parisc 32- and 64bit-kernels can easily crash
> the kernel and as such enforce a DSO.
> A simple testcase is available here: 
> 	http://gsyprf10.external.hp.com/~deller/crash.tgz
> 
> The problem is introduced by the fact, that the handle_interruption()
> crash handler calls the show_regs() function, which in turn tries
> to unwind the stack by calling parisc_show_stack().
> Since the stack contains userspace addresses, a try to unwind 
> the stack is dangerous and useless and leads to the crash.
> 
> The fix is trivial: For userspace processes
> a) avoid to unwind the stack, and
> b) avoid to resolve userspace addresses to kernel symbol names.
> 
> While touching this code, I converted print_symbol() to %pS 
> printk formats and made parisc_show_stack() static.
> 
> An initial patch for this was written by Kyle McMartin back in August:
> http://marc.info/?l=linux-parisc&m=121805168830283&w=2
> 
> Compile and run-tested with a 64bit parisc kernel.
> Patches for -stable series will follow shortly.
> 
> Signed-off-by: Helge Deller <deller@gmx.de>
> 

Sorry, I've been sick for the last few days. I see this has already been
applied, cool.

Anyway, acked-by me.