RE: mutex Giant not owned

2001-08-17 Thread John Baldwin 


On 16-Aug-01 John Baldwin wrote:
 
 On 16-Aug-01 David O'Brien wrote:
# uname -a
 FreeBSD phuong.nuxi.com 5.0-CURRENT FreeBSD 5.0-CURRENT #12: Sun Jul 15
 19:07:45 PDT 2001
 [EMAIL PROTECTED]:/files/Current/sys/alpha/compile/DS20  alpha
 
 Looks like a trapsignal() in trap() is being called w/o Giant.  I'll look at
 it.

Oh, I see why this is busted.  If we take a trap in the kernel while holding
Giant and it ends up doing a goto to 'out' we may unlock Giant while in the
kernel.  I'll try a different approach in a second: just grab Giant around
trapsignal().

-- 

John Baldwin [EMAIL PROTECTED] -- http://www.FreeBSD.org/~jhb/
PGP Key: http://www.baldwin.cx/~john/pgpkey.asc
Power Users Use the Power to Serve!  -  http://www.FreeBSD.org/

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Re: mutex Giant not owned

2001-08-16 Thread Bruce Evans 

On Wed, 15 Aug 2001, David O'Brien wrote:

 panic: mutex Giant not owned at ../../../kern/vfs_subr.c:2363
 ...
 #7  0xfc3d6090 in panic (
 fmt=0xfc5a9096 mutex %s not owned at %s:%d)
 at ../../../kern/kern_shutdown.c:600
 #8  0xfc3ca404 in _mtx_assert (m=0x0, what=0, file=0x0, line=0)
 at ../../../kern/kern_mutex.c:570
 #9  0xfc5303c8 in vm_map_growstack (p=0xfe001fb7ad00,
 addr=301969984) at ../../../vm/vm_map.c:2473
 #10 0xfc5612d8 in grow_stack (p=0x0, sp=0)
 at ../../../alpha/alpha/vm_machdep.c:412
 #11 0xfc553bb0 in sendsig (catcher=0, sig=11, mask=0xfe001fb7aec8,
 code=5905801216) at ../../../alpha/alpha/machdep.c:1388
 #12 0xfc3da534 in trapsignal (p=0xfe001fb7ad00, sig=11,
 code=5905801216) at ../../../kern/kern_sig.c:1060
 #13 0xfc55eecc in trap (a0=5905801216, a1=1, a2=1, entry=2,
 framep=0xfe0023819ed8) at ../../../alpha/alpha/trap.c:617
 #14 0xfc54ccdc in XentMM ()

alpha/trap.c seems to be missing the necessary aquiral of Giant before
calling trapsignal().

Bruce


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RE: mutex Giant not owned

2001-08-16 Thread John Baldwin 


On 16-Aug-01 David O'Brien wrote:
# uname -a
 FreeBSD phuong.nuxi.com 5.0-CURRENT FreeBSD 5.0-CURRENT #12: Sun Jul 15
 19:07:45 PDT 2001
 [EMAIL PROTECTED]:/files/Current/sys/alpha/compile/DS20  alpha

Looks like a trapsignal() in trap() is being called w/o Giant.  I'll look at it.

Try this:

Index: trap.c
===
RCS file: /usr/cvs/src/sys/alpha/alpha/trap.c,v
retrieving revision 1.73
diff -u -r1.73 trap.c
--- trap.c  2001/08/10 22:53:25 1.73
+++ trap.c  2001/08/16 04:29:40
@@ -611,14 +611,15 @@
framep-tf_regs[FRAME_TRAPARG_A0] = a0;
framep-tf_regs[FRAME_TRAPARG_A1] = a1;
framep-tf_regs[FRAME_TRAPARG_A2] = a2;
+   mtx_lock(Giant);
trapsignal(p, i, ucode);
 out:
if (user) {
framep-tf_regs[FRAME_SP] = alpha_pal_rdusp();
userret(p, framep, sticks);
-   if (mtx_owned(Giant))
-   mtx_unlock(Giant);
}
+   if (mtx_owned(Giant))
+   mtx_unlock(Giant);
return;
 
 dopanic:

-- 

John Baldwin [EMAIL PROTECTED] -- http://www.FreeBSD.org/~jhb/
PGP Key: http://www.baldwin.cx/~john/pgpkey.asc
Power Users Use the Power to Serve!  -  http://www.FreeBSD.org/

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