``fatal double fault in supervisor mode''

[Jukka Salmi <j+nbsd%2008.salmi.ch@localhost>]

Hello,

an i386 system running a 5.99.5 kernel (and modules, and a 5.99.01 userland) 
just crashed some seconds after I started a build.  I was running X and blindly 
typed some ddb commands, not seeing if ddb was really receiving them.  It seems 
that `sync' was not successful, but `bt' was; at least that's what dmesg 
reported after the next boot:

fatal double fault in supervisor mode
trap type 13 code 80000000 eip c06bfab7 cs 8 eflags 10296 cr2 cd50dff8 ilevel 1
kernel: supervisor trap double fault, code=0
Stopped in pid 8126.1 (M-zkM-@) at      netbsd:cpu_intr_p+0x7:  call    
netbsd:kpreempt_disable
db{0}> ?
db{0}> db{0}> db{0}> db{0}> db{0}> db{0}> db{0}> db{0}> db{0}> db{0}> 
cpu_intr_p(0,ccf7a2a0,cd545454,cd54539c,0,0,ccf7a294,ffffffff,c0100d7f,cd4d50a0)
 at netbsd:cpu_intr_p+0x7
kpreempt(0,cd5450bc,cd50e054,c06bfacd,ccf7a280,1,cd50e084,c048a7bf,0,ccf7a3f0) 
at netbsd:kpreempt+0x2f
kpreempt_enable(ccf7a280,1,cd50e084,c048a7bf,0,ccf7a3f0,cd547e68,cd547db0,0,0) 
at netbsd:kpreempt_enable+0x38
cpu_intr_p(0,ccf7a3f0,cd547e68,cd547db0,0,0,ccf7a3e4,ffffffff,c0100d7f,cd4d50a0)
 at netbsd:cpu_intr_p+0x1d
kpreempt(0,cd547ad0,cd50e0a4,c06bfacd,ccf7a3d0,1,cd50e0d4,c048a7bf,0,ccf7a3c4) 
at netbsd:kpreempt+0x2f
kpreempt_enable(ccf7a3d0,1,cd50e0d4,c048a7bf,0,ccf7a3c4,cd5478a8,cd5477f0,0,0) 
at netbsd:kpreempt_enable+0x38
cpu_intr_p(0,ccf7a3c4,cd5478a8,cd5477f0,0,0,ccf7a3b8,ffffffff,c0100d7f,cd4d50a0)
 at netbsd:cpu_intr_p+0x1d
kpreempt(0,cd547510,cd50e0f4,c06bfacd,ccf7a3a0,1,cd50e124,c048a7bf,0,ccf7a394) 
at netbsd:kpreempt+0x2f
kpreempt_enable(ccf7a3a0,1,cd50e124,c048a7bf,0,ccf7a394,cd5472e8,cd547230,0,0) 
at netbsd:kpreempt_enable+0x38
cpu_intr_p(0,ccf7a394,cd5472e8,cd547230,0,0,ccf7a388,ffffffff,c0100d7f,cd4d50a0)
 at netbsd:cpu_intr_p+0x1d
kpreempt(0,cd549f24,cd50e144,c06bfacd,ccf7a4f0,1,cd50e174,c048a7bf,0,ccf7a4e4) 
at netbsd:kpreempt+0x2f
kpreempt_enable(ccf7a4f0,1,cd50e174,c048a7bf,0,ccf7a4e4,cd549cfc,cd549c44,0,0) 
at netbsd:kpreempt_enable+0x38
cpu_intr_p(0,ccf7a4e4,cd549cfc,cd549c44,0,0,ccf7a4dc,ffffffff,c0100d7f,cd4d50a0db{0}>
 
cpu_intr_p(0,ccf7a2a0,cd545454,cd54539c,0,0,ccf7a294,ffffffff,c0100d7f,cd4d50a0)
 at netbsd:cpu_intr_p+0x7
kpreempt(0,cd5450bc,cd50e054,c06bfacd,ccf7a280,1,cd50e084,c048a7bf,0,ccf7a3f0) 
at netbsd:kpreempt+0x2f
kpreempt_enable(ccf7a280,1,cd50e084,c048a7bf,0,ccf7a3f0,cd547e68,cd547db0,0,0) 
at netbsd:kpreempt_enable+0x38
cpu_intr_p(0,ccf7a3f0,cd547e68,cd547db0,0,0,ccf7a3e4,ffffffff,c0100d7f,cd4d50a0)
 at netbsd:cpu_intr_p+0x1d
kpreempt(0,cd547ad0,cd50e0a4,c06bfacd,ccf7a3d0,1,cd50e0d4,c048a7bf,0,ccf7a3c4) 
at netbsd:kpreempt+0x2f
kpreempt_enable(ccf7a3d0,1,cd50e0d4,c048a7bf,0,ccf7a3c4,cd5478a8,cd5477f0,0,0) 
at netbsd:kpreempt_enable+0x38
cpu_intr_p(0,ccf7a3c4,cd5478a8,cd5477f0,0,0,ccf7a3b8,ffffffff,c0100d7f,cd4d50a0)
 at netbsd:cpu_intr_p+0x1d
kpreempt(0,cd547510,cd50e0f4,c06bfacd,ccf7a3a0,1,cd50e124,c048a7bf,0,ccf7a394) 
at netbsd:kpreempt+0x2f
kpreempt_enable(ccf7a3a0,1,cd50e124,c048a7bf,0,ccf7a394,cd5472e8,cd547230,0,0) 
at netbsd:kpreempt_enable+0x38
cpu_intr_p(0,ccf7a394,cd5472e8,cd547230,0,0,ccf7a388,ffffffff,c0100d7f,cd4d50a0)
 at netbsd:cpu_intr_p+0x1d
kpreempt(0,cd549f24,cd50e144,c06bfacd,ccf7a4f0,1,cd50e174,c048a7bf,0,ccf7a4e4) 
at netbsd:kpreempt+0x2f

Any hints?


TIA, Jukka

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