From 19306059cd7fedaf96b4b0260a9a8a45e513c857 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 6 Sep 2005 15:16:35 -0700 Subject: [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: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/traps.c | 4 ++-- arch/x86_64/kernel/nmi.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) (limited to 'arch') diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index 54629bb5893..029bf94cda7 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 84cae81fff8..caf164959e1 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) -- cgit v1.2.3