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27 March 2024, 02:37:15 UTC
Revision c20a84c91048c76c1379011c96b1a5cee5c7d9a0 authored by Kyle McMartin on 01 March 2008, 18:25:52 UTC, committed by Kyle McMartin on 16 March 2008, 02:12:17 UTC 
[PARISC] futex: special case cmpxchg NULL in kernel space
 
Commit a0c1e9073ef7428a14309cba010633a6cd6719ea added code to futex.c
to detect whether futex_atomic_cmpxchg_inatomic was implemented at run
time:

+       curval = cmpxchg_futex_value_locked(NULL, 0, 0);
+       if (curval == -EFAULT)
+               futex_cmpxchg_enabled = 1;

This is bogus on parisc, since page zero in kernel virtual space is the
gateway page for syscall entry, and should not be read from the kernel.
(That, and we really don't like the kernel faulting on its own address
 space...)

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
1 parent dc39455
History
Tip revision: c20a84c91048c76c1379011c96b1a5cee5c7d9a0 authored by Kyle McMartin on 01 March 2008, 18:25:52 UTC
[PARISC] futex: special case cmpxchg NULL in kernel space
Tip revision: c20a84c
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