From: Russell King <rmk@dyn-67.arm.linux.org.uk>
Date: Sat, 2 Jun 2007 14:36:37 +0000 (+0100)
Subject: [ARM] Solve buggy smp_processor_id() usage
X-Git-Tag: v2.6.22-rc5~97^2~3
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f72267c30f5a08f9a77c97417ec120e6943195f8;p=linux-2.6

[ARM] Solve buggy smp_processor_id() usage

BUG: using smp_processor_id() in preemptible [00000001] code: opcontrol/427

Resolve this bug by ensuring that we're not using smp_processor_id() in
a preemptable context (by disabling preemption.)

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---

diff --git a/arch/arm/oprofile/op_model_mpcore.c b/arch/arm/oprofile/op_model_mpcore.c
index 7791da791f..75bae06792 100644
--- a/arch/arm/oprofile/op_model_mpcore.c
+++ b/arch/arm/oprofile/op_model_mpcore.c
@@ -200,8 +200,10 @@ static int em_call_function(int (*fn)(void))
 	data.fn = fn;
 	data.ret = 0;
 
+	preempt_disable();
 	smp_call_function(em_func, &data, 1, 1);
 	em_func(&data);
+	preempt_enable();
 
 	return data.ret;
 }