[Linux-ia64] Re: kernel update (relative to 2.4.18)

[Xavier Bru <Xavier.Bru@bull.net>]

>	- Install NaT-page at address zero to speed up speculation
>	  across NULL pointers (Ken Chen).

Hi Dave,


It seems that null pointers passed as argument to syscalls by wrong
user code now generate a Oops, and enter kdb if enabled. 

This is not a big problem, as typing "go"  the wrong process 
exits and everyting goes well. 

for example: 

quotaon[163]: NaT consumption 17179869216

Pid: 163, comm:              quotaon
psr : 0000101008026018 ifs : 8000000000000183 ip  : [<e000000004767e00>]    Not tainted
unat: 0000000000000000 pfs : 0000000000000288 rsc : 0000000000000003
rnat: 0000101008026018 bsps: e000000004402f00 pr  : 0000000056609617
ldrs: 0000000000000000 ccv : 0000000000000000 fpsr: 0009804c0270033f
b0  : e0000000044d8e50 b6  : e000000004402f60 b7  : e0000000045f6300
f6  : 1003e0000000000000001 f7  : 1003e0000000000000001
f8  : 1003e0000000000000170 f9  : 10005c200000000000000
r1  : e000000004cbe970 r2  : 0000000000000288 r3  : e000000004abfb88
r8  : 0000000000000000 r9  : 0000000000000000 r10 : 0000000000001000
r11 : 00000fffffffbfff r12 : e00000003f21fe30 r13 : e00000003f218000
r14 : 9fffffffffffffff r15 : 0000000000000000 r16 : 0000000000000000
r17 : e00000003fc13418 r18 : e00000003fc13368 r19 : 0000000000000001
r20 : 0000000000000001 r21 : 0000000000004000 r22 : e00000003fcd08d8
r23 : e00000003fcd08d0 r24 : 0000000000000010 r25 : 0000000000000002
r26 : e00000003f2184c8 r27 : 60000fffffffba60 r28 : 0000000000000100
r29 : 0000000000000000 r30 : 0000000000000100 r31 : e00000003f218008

Call Trace: [<e00000000440fea0>] sp=0xe00000003f21f9d0 bsp=0xe00000003f219178
[<e000000004427c40>] sp=0xe00000003f21fb90 bsp=0xe00000003f219150
[<e000000004428c10>] sp=0xe00000003f21fb90 bsp=0xe00000003f219118
[<e000000004409fa0>] sp=0xe00000003f21fc90 bsp=0xe00000003f219118
[<e000000004767e00>] sp=0xe00000003f21fe30 bsp=0xe00000003f219100
[<e0000000044d8e50>] sp=0xe00000003f21fe30 bsp=0xe00000003f2190d8
[<e0000000044dc400>] sp=0xe00000003f21fe30 bsp=0xe00000003f2190b0
[<e000000004506cc0>] sp=0xe00000003f21fe30 bsp=0xe00000003f219018
[<e000000004409f80>] sp=0xe00000003f21fe60 bsp=0xe00000003f219018
 
Entering kdb (current=0xe00000003f218000, pid 163) on processor 1 Oops: <NULL>
due to oops @ 0xe000000004767e00
 psr: 0x0000101008026018   ifs: 0x8000000000000183    ip: 0xe000000004767e00  
unat: 0x0000000000000000   pfs: 0x0000000000000288   rsc: 0x0000000000000003  
rnat: 0x0000101008026018  bsps: 0xe000000004402f00    pr: 0x0000000056609617  
ldrs: 0x0000000000000000   ccv: 0x0000000000000000  fpsr: 0x0009804c0270033f  
  b0: 0xe0000000044d8e50    b6: 0xe000000004402f60    b7: 0xe0000000045f6300  
  r1: 0xe000000004cbe970    r2: 0x0000000000000288    r3: 0xe000000004abfb88  
  r8: 0x0000000000000000    r9: 0x0000000000000000   r10: 0x0000000000001000  
 r11: 0x00000fffffffbfff   r12: 0xe00000003f21fe30   r13: 0xe00000003f218000  
 r14: 0x9fffffffffffffff   r15: 0x0000000000000000   r16: 0x0000000000000000  
 r17: 0xe00000003fc13418   r18: 0xe00000003fc13368   r19: 0x0000000000000001  
 r20: 0x0000000000000001   r21: 0x0000000000004000   r22: 0xe00000003fcd08d8  
 r23: 0xe00000003fcd08d0   r24: 0x0000000000000010   r25: 0x0000000000000002  
 r26: 0xe00000003f2184c8   r27: 0x60000fffffffba60   r28: 0x0000000000000100  
 r29: 0x0000000000000000   r30: 0x0000000000000100   r31: 0xe00000003f218008  
&regs = e00000003f21fca0
[1]kdb> bt
0xe000000004767e00 __strncpy_from_user+0x20
        args (0xe00000003fb41000, 0x0, 0x1000)
        kernel .text 0xe000000004400000 0xe000000004767de0 0xe000000004767e40
0xe0000000044d8e50 getname+0x170
        args (0x0, 0x1000, 0xe00000003fb41000, 0xe0000000044dc400, 0x288)
        kernel .text 0xe000000004400000 0xe0000000044d8ce0 0xe0000000044d8ec0
0xe0000000044dc400 __user_walk+0x20
        args (0x0, 0x9, 0xe00000003f21fe40, 0xe000000004506cc0, 0x998)
        kernel .text 0xe000000004400000 0xe0000000044dc3e0 0xe0000000044dc4e0
0xe000000004506cc0 sys_quotactl+0x1c0
        args (0x110000, 0x0, 0x0, 0x60000fffffffbc30, 0x40000000000084d0)
        kernel .text 0xe000000004400000 0xe000000004506b00 0xe0000000045071a0
0xe000000004409f80 ia64_ret_from_syscall
        args (0x110000, 0x0, 0x0, 0x60000fffffffbc30, 0x40000000000084d0)
        kernel .text 0xe000000004400000 0xe000000004409f80 0xe000000004409fa0

-- 

 Sincères salutations.
_____________________________________________________________________
 
Xavier BRU                 BULL ISD/R&D/INTEL office:     FREC B1-422
tel : +33 (0)4 76 29 77 45                    http://www-frec.bull.fr
fax : +33 (0)4 76 29 77 70                 mailto:Xavier.Bru@bull.net
addr: BULL, 1 rue de Provence, BP 208, 38432 Echirolles Cedex, FRANCE
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