Re: [PATCH] parisc: Try to fix random segmentation faults in package builds

[John David Anglin <dave.anglin@bell.net>]

On 2024-05-08 4:52 p.m., John David Anglin wrote:
>> with no accompanying stack trace and then the BMC would restart the whole machine automatically.  These were infrequent enough that the 
>> segfaults were the bigger problem, but after applying this patch on top of 6.8, this changed the dynamic.  It seems to occur during builds 
>> with varying I/O loads.  For example, I was able to build gcc fine, with no segfaults, but I was unable to build perl, a much smaller build, 
>> without crashing the machine. I did not observe any segfaults over the day or 2 I ran this patch, but that's not an unheard-of stretch of 
>> time even without it, and I am being forced to revert because of the panics.
> Looks like there is a problem with 6.8.  I'll do some testing with it.
So far, I haven't seen any panics with 6.8.9 but I have seen some random segmentation faults
in the gcc testsuite.  I looked at one ld fault in some detail.  18 contiguous words in the  elf_link_hash_entry
struct were zeroed starting with the last word in the bfd_link_hash_entry struct causing the fault.
The section pointer was zeroed.

18 words is a rather strange number of words to corrupt and corruption doesn't seem related
to object structure.  In any case, it is not page related.

It's really hard to tell how this happens.  The corrupt object was at a slightly different location
than it is when ld is run under gdb.  Can't duplicate in gdb.

Dave

-- 
John David Anglin  dave.anglin@bell.net