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authorPaul E. McKenney <paulmck@us.ibm.com>2005-09-07 00:16:35 +0200
committerLinus Torvalds <torvalds@g5.osdl.org>2005-09-08 01:57:19 +0200
commit19306059cd7fedaf96b4b0260a9a8a45e513c857 (patch)
tree7c32d59c1a5830689d5f85a7f81e89e48d1097ae /arch
parent[PATCH] Provide better printk() support for SMP machines (diff)
downloadlinux-19306059cd7fedaf96b4b0260a9a8a45e513c857.tar.xz
linux-19306059cd7fedaf96b4b0260a9a8a45e513c857.zip
[PATCH] NMI: Update NMI users of RCU to use new API
Uses of RCU for dynamically changeable NMI handlers need to use the new rcu_dereference() and rcu_assign_pointer() facilities. This change makes it clear that these uses are safe from a memory-barrier viewpoint, but the main purpose is to document exactly what operations are being protected by RCU. This has been tested on x86 and x86-64, which are the only architectures affected by this change. Signed-off-by: <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/i386/kernel/traps.c4
-rw-r--r--arch/x86_64/kernel/nmi.c4
2 files changed, 4 insertions, 4 deletions
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 54629bb5893a..029bf94cda7d 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -657,7 +657,7 @@ fastcall void do_nmi(struct pt_regs * regs, long error_code)
++nmi_count(cpu);
- if (!nmi_callback(regs, cpu))
+ if (!rcu_dereference(nmi_callback)(regs, cpu))
default_do_nmi(regs);
nmi_exit();
@@ -665,7 +665,7 @@ fastcall void do_nmi(struct pt_regs * regs, long error_code)
void set_nmi_callback(nmi_callback_t callback)
{
- nmi_callback = callback;
+ rcu_assign_pointer(nmi_callback, callback);
}
EXPORT_SYMBOL_GPL(set_nmi_callback);
diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c
index 84cae81fff8b..caf164959e19 100644
--- a/arch/x86_64/kernel/nmi.c
+++ b/arch/x86_64/kernel/nmi.c
@@ -524,14 +524,14 @@ asmlinkage void do_nmi(struct pt_regs * regs, long error_code)
nmi_enter();
add_pda(__nmi_count,1);
- if (!nmi_callback(regs, cpu))
+ if (!rcu_dereference(nmi_callback)(regs, cpu))
default_do_nmi(regs);
nmi_exit();
}
void set_nmi_callback(nmi_callback_t callback)
{
- nmi_callback = callback;
+ rcu_assign_pointer(nmi_callback, callback);
}
void unset_nmi_callback(void)