strace on Linux/MIPS?

strace on Linux/MIPS?

[Jun Sun]

Has anybody been successful in trying to get strace running on
Linux/MIPS?  I managed to get 4.2, with a little from CVS tree, compiled
and run.  However, it does not quite right.  It only prints the first
system. See below.  Verified that this is the same behavior on both
2.3.99-pre3 and 2.4.0-test2.

sh-2.03# strace ls
execve("/bin/ls", ["ls"], [/* 14 vars */]) = 0
bin  boot  dev  etc  lib  mnt  opt  proc  sbin  share  tmp  var

Any idea?

Jun

Re: strace on Linux/MIPS?

[Keith M Wesolowski]

On Thu, Jul 27, 2000 at 04:05:08PM -0700, Jun Sun wrote:

> Has anybody been successful in trying to get strace running on
> Linux/MIPS?  I managed to get 4.2, with a little from CVS tree, compiled
> and run.  However, it does not quite right.  It only prints the first
> system. See below.  Verified that this is the same behavior on both
> 2.3.99-pre3 and 2.4.0-test2.

Your kernel is too old. Ralf fixed some things in ptrace a few days
ago. Also, I would be interested in hearing if you can get 4.2 to
work. I found that, even after adjusting several places for
__NR_Linux, it segfaulted. I do have 3.1 from oss.sgi.com CVS (with a
couple minor glibc 2.2 patches) working properly with a current
kernel.

-- 
Keith M Wesolowski			wesolows@chem.unr.edu
University of Nevada			http://www.chem.unr.edu
Chemistry Department Systems and Network Administrator

Re: strace on Linux/MIPS?

[Jun Sun]

Keith M Wesolowski wrote:
> 
> On Thu, Jul 27, 2000 at 04:05:08PM -0700, Jun Sun wrote:
> 
> > Has anybody been successful in trying to get strace running on
> > Linux/MIPS?  I managed to get 4.2, with a little from CVS tree, compiled
> > and run.  However, it does not quite right.  It only prints the first
> > system. See below.  Verified that this is the same behavior on both
> > 2.3.99-pre3 and 2.4.0-test2.
> 
> Your kernel is too old.

Wow, a couple days is "too old".  I guest that is Linux speed.

> Ralf fixed some things in ptrace a few days
> ago. 

Great!  Can you pinpoint the related files?  I took a snapshot of CVS on
6/27 and hacked heavily to get it work on my NEC board.  It would be
very difficult for me to move to the new kernel.  It would be better if
I can just reverse-merge with the related changes.

Jun

Re: strace on Linux/MIPS?

[Ralf Baechle]

On Thu, Jul 27, 2000 at 04:46:56PM -0700, Jun Sun wrote:

> > > Has anybody been successful in trying to get strace running on
> > > Linux/MIPS?  I managed to get 4.2, with a little from CVS tree, compiled
> > > and run.  However, it does not quite right.  It only prints the first
> > > system. See below.  Verified that this is the same behavior on both
> > > 2.3.99-pre3 and 2.4.0-test2.
> > 
> > Your kernel is too old.
> 
> Wow, a couple days is "too old".  I guest that is Linux speed.

Software is like fish, it starts to smell soon :-)

> > Ralf fixed some things in ptrace a few days
> > ago. 
> 
> Great!  Can you pinpoint the related files?  I took a snapshot of CVS on
> 6/27 and hacked heavily to get it work on my NEC board.  It would be
> very difficult for me to move to the new kernel.  It would be better if
> I can just reverse-merge with the related changes.

arch/mips/kernel/scall_o32.S
arch/mips/tools/offset.c
arch/mips64/kernel/scall_64.S
arch/mips64/kernel/scall_o32.S
arch/mips64/tools/offset.c

  Ralf

Re: strace on Linux/MIPS?

[Jun Sun]

Ralf Baechle wrote:
> 
> > > Ralf fixed some things in ptrace a few days
> > > ago.
> >
> > Great!  Can you pinpoint the related files?  I took a snapshot of CVS on
> > 6/27 and hacked heavily to get it work on my NEC board.  It would be
> > very difficult for me to move to the new kernel.  It would be better if
> > I can just reverse-merge with the related changes.
> 
> arch/mips/kernel/scall_o32.S
> arch/mips/tools/offset.c
> arch/mips64/kernel/scall_64.S
> arch/mips64/kernel/scall_o32.S
> arch/mips64/tools/offset.c
> 
>   Ralf

I just updated offset.c and scall_o32.S.  After a trial change ("nice"
-> "priority") in offset.c, strace seems to work fine now.

However, I did notice an error message for mmap(...).

mmap(ptrace: umoven: Input/output error
ptrace: umoven: Input/output error
)                                  = 717291520

Keith, if you want the patch for strace 4.2, I can send it to you.  

Jun

Re: strace on Linux/MIPS?

[Ralf Baechle]

On Thu, Jul 27, 2000 at 07:12:44PM -0700, Jun Sun wrote:

> I just updated offset.c and scall_o32.S.  After a trial change ("nice"
> -> "priority") in offset.c, strace seems to work fine now.
> 
> However, I did notice an error message for mmap(...).
> 
> mmap(ptrace: umoven: Input/output error
> ptrace: umoven: Input/output error
> )                                  = 717291520

Looks like strace is still tryping to copy mmap_arg_struct like on Intel
but on MIPS we don't use that?

> Keith, if you want the patch for strace 4.2, I can send it to you.  

  Ralf

Re: strace on Linux/MIPS?

[Maciej W. Rozycki]

On Thu, 27 Jul 2000, Jun Sun wrote:

> Great!  Can you pinpoint the related files?  I took a snapshot of CVS on
> 6/27 and hacked heavily to get it work on my NEC board.  It would be
> very difficult for me to move to the new kernel.  It would be better if
> I can just reverse-merge with the related changes.

 Well, you can always take a unified diff of your own changes and try to
apply it to a new snapshot.  Depending on the amount of changes you might
need to apply certain hunks manually but the overall process is usually
quite easy. 

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: macro@ds2.pg.gda.pl, PGP key available        +

Re: strace on Linux/MIPS?

[Wichert Akkerman]

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Previously Ralf Baechle wrote:
> Looks like strace is still tryping to copy mmap_arg_struct like on Intel
> but on MIPS we don't use that?

Could be, I think MIPS and i386 use the same codepath there. Patches
are appreciated so I can include them in strace 4.3 (eta 3 weeks from
now)

Wichert.

-- 
  _________________________________________________________________
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| wichert@wiggy.net                   http://www.liacs.nl/~wichert/ |
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Re: strace on Linux/MIPS?

[Ralf Baechle]

On Fri, Jul 28, 2000 at 01:51:39PM +0200, Wichert Akkerman wrote:

> Previously Ralf Baechle wrote:
> > Looks like strace is still tryping to copy mmap_arg_struct like on Intel
> > but on MIPS we don't use that?
> 
> Could be, I think MIPS and i386 use the same codepath there. Patches
> are appreciated so I can include them in strace 4.3 (eta 3 weeks from
> now)

Well, they shouldn't use the same code ...

Bananaware patch below.

  Ralf

--- strace/linux/mips/syscallent.orig	Mon May  1 03:09:31 2000
+++ strace/linux/mips/syscallent.h	Fri Jul 28 19:50:13 2000
@@ -4088,7 +4088,7 @@
 	{ 1,	TF,	sys_swapon,		"swapon"	}, /* 4087 */
 	{ 3,	0,	sys_reboot,		"reboot"	}, /* 4088 */
 	{ 3,	0,	sys_readdir,		"readdir"	}, /* 4089 */
-	{ 6,	0,	sys_old_mmap,		"mmap"		}, /* 4090 */
+	{ 6,	0,	sys_mmap,		"mmap"		}, /* 4090 */
 	{ 2,	0,	sys_munmap,		"munmap"	}, /* 4091 */
 	{ 2,	TF,	sys_truncate,		"truncate"	}, /* 4092 */
 	{ 2,	0,	sys_ftruncate,		"ftruncate"	}, /* 4093 */

Re: strace on Linux/MIPS?

[Ralf Baechle]

On Fri, Jul 28, 2000 at 01:51:39PM +0200, Wichert Akkerman wrote:

> Previously Ralf Baechle wrote:
> > Looks like strace is still tryping to copy mmap_arg_struct like on Intel
> > but on MIPS we don't use that?
> 
> Could be, I think MIPS and i386 use the same codepath there. Patches
> are appreciated so I can include them in strace 4.3 (eta 3 weeks from
> now)

Here's the second strace patch, please apply.

I noticed that process.c:change_syscall() can't work as is - the all kernels
would change the v0 register - and happily use the old value that is take
the wrong syscall.  A kernel buglet which also hits the usermode kernel
and which I'll fix asap.

  Ralf

--- strace/process.c.orig	Fri Jul 28 23:37:14 2000
+++ strace/process.c	Fri Jul 28 23:33:43 2000
@@ -502,6 +502,24 @@
 		if (errno)
 			return -1;
 	}
+#elif defined(MIPS)
+	{
+		errno = 0;
+		if (argnum < 4)
+			ptrace(PTRACE_POKEUSER, tcp->pid,
+			       (char*)(REG_A0 + argnum), tcp->u_arg[argnum]);
+		else {
+			unsigned long *sp;
+
+			if (upeek(tcp->pid, REG_SP, (long *) &sp) , 0)
+				return -1;
+
+			ptrace(PTRACE_POKEDATA, tcp->pid,
+			       (char*)(sp + argnum - 4), tcp->u_arg[argnum]);
+		}
+		if (errno)
+			return -1;
+	}
 #else
 # warning Sorry, setargs not implemented for this architecture.
 #endif