From: David Miller <da...@davemloft.net>
Date: Tue, 20 Nov 2012 14:59:10 -0500 (EST)
> From: Konstantin Serebryany <konstantin.s.serebry...@gmail.com>
> Date: Tue, 20 Nov 2012 23:52:48 +0400
>
>> Please apply whatever minimal patch required to unbreak the SPARC
>> build. We will not be accepting any non-trivial patches until we
>> set up semi-automated way to pull the upstream sources.
>
> Will do.
I tossed together a quick sparc implementation and there seems to
be only two issues to fix:
1) As noticed by the powerpc people, you have to probe the page
size of the system properly. It's variable even within a
target/OS.
Probably a new hook, implemented in asan_linux.cc via:
#include <unistd.h>
uptr GetPageSize()
{
return getpagesize();
}
I would just get rid of kPageSizeBits, rather than compute it
dynamically as well, as it's really not used as far as I can tell.
The mmap of the shadow area won't work on sparc without this being
resolved.
2) The current code emitted to set the shadow values results in
unaligned stores. For example, for the memcmp-1.c test on 32-bit
we get:
0x10488 <main+8>: add %fp, -160, %i5
...
0x10490 <main+16>: sethi %hi(0xf1f1f000), %g2
...
0x104a0 <main+32>: srl %i5, 3, %i5
...
0x104a8 <main+40>: or %g2, 0x1f1, %g2
0x104ac <main+44>: sethi %hi(0x20000000), %g1
...
=> 0x104b4 <main+52>: st %g2, [ %i5 + %g1 ]
Here %fp is 0xffffd538, and this %i5 + %g1 is 0x3ffffa93, which
is not aligned properly for a 32-bit store.
Therefore, this won't work for any STRICT_ALIGNMENT target.
Those seem to be the only problems that need to be resolved for this
feature to be fully working.
