Re: BUG: BUS error while returning from read() in /dev/oprofile/buffer

[David Daney <ddaney@avtrex.com>]

Anirban Sinha wrote:
> Hi:
> 
>  
> 
> I have been trying to hunt down this bug for several days now. What 
> mainly happens is that when oprofiled wakes up from read() in 
> /dev/oprofile/buffer on receiving a signal USR1 (i.e, when someone does 
> opcontrol –start after doing opcontrol—start-daemon), it somehow gets 
> SIGBUS within glibc read().  We are using a mips machine with Sybyte SB1 
> processor. On intel, this error does not show up. Interestingly, when I 
> tried running a small test program that simply reads 
> /dev/oprofile/buffer, the error can’t be reproduced!
> 
>  
> 
> Ralf and others, any insights, suggestions or useful comments from 
> experience will be really really appreciated. I am spending a lot of 
> time trying to fix this bug.
> 

Likely you did a cross build of bash and your signal numbers are incorrect.

On the system where you built bash, SIGUSR1 is 10.

On the mips-linux target signal 10 is SIGBUS so when the bash kill 
builtin thinks it is sending SIGUSR1 it is really sending SIGBUS.

David Daney