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| author | Jason Wessel <jason.wessel@windriver.com> | 2010-04-02 14:58:18 -0500 |
|---|---|---|
| committer | Jason Wessel <jason.wessel@windriver.com> | 2010-04-02 14:58:18 -0500 |
| commit | ae6bf53e0255c8ab04b6fe31806e318432570e3c (patch) | |
| tree | d4726e48bfe5e0dd6ce4061551af3d0518efbe83 | |
| parent | 62fae312197a8fbcd3727261d59f5a6bd0dbf158 (diff) | |
| download | linux-ae6bf53e0255c8ab04b6fe31806e318432570e3c.tar.bz2 | |
kgdb: use atomic_inc and atomic_dec instead of atomic_set
Memory barriers should be used for the kgdb cpu synchronization. The
atomic_set() does not imply a memory barrier.
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
| -rw-r--r-- | kernel/kgdb.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/kernel/kgdb.c b/kernel/kgdb.c index 6882c047452d..2f7f454605c2 100644 --- a/kernel/kgdb.c +++ b/kernel/kgdb.c @@ -1379,8 +1379,7 @@ acquirelock: * Make sure the above info reaches the primary CPU before * our cpu_in_kgdb[] flag setting does: */ - smp_wmb(); - atomic_set(&cpu_in_kgdb[cpu], 1); + atomic_inc(&cpu_in_kgdb[cpu]); /* * CPU will loop if it is a slave or request to become a kgdb @@ -1400,7 +1399,7 @@ return_normal: */ if (arch_kgdb_ops.correct_hw_break) arch_kgdb_ops.correct_hw_break(); - atomic_set(&cpu_in_kgdb[cpu], 0); + atomic_dec(&cpu_in_kgdb[cpu]); touch_softlockup_watchdog_sync(); clocksource_touch_watchdog(); local_irq_restore(flags); @@ -1449,7 +1448,7 @@ return_normal: */ if (!kgdb_single_step) { for (i = 0; i < NR_CPUS; i++) - atomic_set(&passive_cpu_wait[i], 1); + atomic_inc(&passive_cpu_wait[i]); } #ifdef CONFIG_SMP @@ -1483,11 +1482,11 @@ return_normal: if (kgdb_io_ops->post_exception) kgdb_io_ops->post_exception(); - atomic_set(&cpu_in_kgdb[ks->cpu], 0); + atomic_dec(&cpu_in_kgdb[ks->cpu]); if (!kgdb_single_step) { for (i = NR_CPUS-1; i >= 0; i--) - atomic_set(&passive_cpu_wait[i], 0); + atomic_dec(&passive_cpu_wait[i]); /* * Wait till all the CPUs have quit * from the debugger. @@ -1736,11 +1735,11 @@ EXPORT_SYMBOL_GPL(kgdb_unregister_io_module); */ void kgdb_breakpoint(void) { - atomic_set(&kgdb_setting_breakpoint, 1); + atomic_inc(&kgdb_setting_breakpoint); wmb(); /* Sync point before breakpoint */ arch_kgdb_breakpoint(); wmb(); /* Sync point after breakpoint */ - atomic_set(&kgdb_setting_breakpoint, 0); + atomic_dec(&kgdb_setting_breakpoint); } EXPORT_SYMBOL_GPL(kgdb_breakpoint); |