Re: [linuxsh-dev] Unaligned access crash in signal handlers

[SUGIOKA T. <su...@it...>]

At 18:45 01/01/16 +1100, Denis Dowling wrote:
>I have been getting rare crashes in Linux 2.4.0 when handling SIGALRM
>signals. I have managed to trace the problem down and it seems that the
>sigreturn trap code is not getting flushed to the signal frame
>sometimes. The problem goes away completely if I do a flush_cache_all
>instead of flush_icache_range. I have attached a patch that does this. I
>cannot see anything wrong with the current flush_icache_range usage but
>suspect it is broken. The flush_cache_all is complete overkill so would
>be very keen to hear if you have a fix for flush_icache_range.

Currently flush_icache_range uses A-bit. but A-bit works only when
ITLB entry exists. UTLB entry should not work.
So every I-cache entry should be compared with physical address by hand
or all I-cache should be invalidated.


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SUGIOKA Toshinobu