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| author | David S. Miller <davem@davemloft.net> | 2016-08-18 01:17:32 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-08-18 01:17:32 -0400 |
| commit | 60747ef4d173c2747bf7f0377fb22846cb422195 (patch) | |
| tree | ea0faf33b952495c47909be1400c475a3f3821b0 /kernel/futex.c | |
| parent | 484334198f8ce9552e20930fff9408ebf6bcf94d (diff) | |
| parent | 184ca823481c99dadd7d946e5afd4bb921eab30d (diff) | |
| download | linux-60747ef4d173c2747bf7f0377fb22846cb422195.tar.gz linux-60747ef4d173c2747bf7f0377fb22846cb422195.tar.bz2 linux-60747ef4d173c2747bf7f0377fb22846cb422195.zip | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Minor overlapping changes for both merge conflicts.
Resolution work done by Stephen Rothwell was used
as a reference.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/futex.c')
| -rw-r--r-- | kernel/futex.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 33664f70e2d2..46cb3a301bc1 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -179,7 +179,15 @@ int __read_mostly futex_cmpxchg_enabled; * Futex flags used to encode options to functions and preserve them across * restarts. */ -#define FLAGS_SHARED 0x01 +#ifdef CONFIG_MMU +# define FLAGS_SHARED 0x01 +#else +/* + * NOMMU does not have per process address space. Let the compiler optimize + * code away. + */ +# define FLAGS_SHARED 0x00 +#endif #define FLAGS_CLOCKRT 0x02 #define FLAGS_HAS_TIMEOUT 0x04 @@ -405,6 +413,16 @@ static void get_futex_key_refs(union futex_key *key) if (!key->both.ptr) return; + /* + * On MMU less systems futexes are always "private" as there is no per + * process address space. We need the smp wmb nevertheless - yes, + * arch/blackfin has MMU less SMP ... + */ + if (!IS_ENABLED(CONFIG_MMU)) { + smp_mb(); /* explicit smp_mb(); (B) */ + return; + } + switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) { case FUT_OFF_INODE: ihold(key->shared.inode); /* implies smp_mb(); (B) */ @@ -436,6 +454,9 @@ static void drop_futex_key_refs(union futex_key *key) return; } + if (!IS_ENABLED(CONFIG_MMU)) + return; + switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) { case FUT_OFF_INODE: iput(key->shared.inode); |