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From: Guillaume Chazarain <guichaz@yahoo.fr>
To: cpufreq@lists.linux.org.uk
Subject: Uninitialized use of cmd.val in arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c:423
Date: Tue, 02 Jan 2007 16:49:17 +0100	[thread overview]
Message-ID: <459A7EFD.2040204@yahoo.fr> (raw)

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Hi,

In arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c:acpi_cpufreq_target()
cmd.val = (cmd.val & ~INTEL_MSR_RANGE) | msr;

cmd.val seems to be used uninitialized. So, one of the attached patch
should be needed. Both patches, and no patch at all, work for me though.

This is linux-2.6.20-rc3 and the code is really executed (I traced it) with
my Pentium M.

Thanks.

-- 
Guillaume


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diff -r 90710ed1291f arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
--- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c	Mon Jan 01 01:00:04 2007 +0000
+++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c	Tue Jan 02 16:26:29 2007 +0100
@@ -372,7 +372,6 @@ static int acpi_cpufreq_target(struct cp
 	struct cpufreq_freqs freqs;
 	cpumask_t online_policy_cpus;
 	struct drv_cmd cmd;
-	unsigned int msr;
 	unsigned int next_state = 0;
 	unsigned int next_perf_state = 0;
 	unsigned int i;
@@ -417,10 +416,9 @@ static int acpi_cpufreq_target(struct cp
 	case SYSTEM_INTEL_MSR_CAPABLE:
 		cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 		cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
-		msr =
+		cmd.val =
 		    (u32) perf->states[next_perf_state].
 		    control & INTEL_MSR_RANGE;
-		cmd.val = (cmd.val & ~INTEL_MSR_RANGE) | msr;
 		break;
 	case SYSTEM_IO_CAPABLE:
 		cmd.type = SYSTEM_IO_CAPABLE;

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diff -r 90710ed1291f arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
--- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c	Mon Jan 01 01:00:04 2007 +0000
+++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c	Tue Jan 02 16:27:47 2007 +0100
@@ -420,6 +420,7 @@ static int acpi_cpufreq_target(struct cp
 		msr =
 		    (u32) perf->states[next_perf_state].
 		    control & INTEL_MSR_RANGE;
+		cmd.val = get_cur_val(online_policy_cpus);
 		cmd.val = (cmd.val & ~INTEL_MSR_RANGE) | msr;
 		break;
 	case SYSTEM_IO_CAPABLE:

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             reply	other threads:[~2007-01-02 15:49 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-02 15:49 Guillaume Chazarain [this message]
2007-01-02 17:57 ` Uninitialized use of cmd.val inarch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c:423 Pallipadi, Venkatesh
2007-01-02 18:58   ` [PATCH] Uninitialized use of cmd.val in arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c:acpi_cpufreq_target() Guillaume Chazarain

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