2009-06-17 14:25:31

by Figo.zhang

Subject: [PATCH]io_apic.c: fix compile warning

fix compile warning:
arch/x86/kernel/apic/io_apic.c: In function ‘ioapic_write_entry’:
arch/x86/kernel/apic/io_apic.c:466: warning: ‘eu’ is used uninitialized in this function
arch/x86/kernel/apic/io_apic.c:465: note: ‘eu’ was declared here

Signed-off-by: Figo.zhang <[email protected]>
---

arch/x86/kernel/apic/io_apic.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index ef8d929..e9ca066 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -462,7 +462,7 @@ static struct IO_APIC_route_entry ioapic_read_entry(int apic, int pin)
static void
__ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
{
- union entry_union eu;
+ union entry_union eu = {{0,0}};
eu.entry = e;
io_apic_write(apic, 0x11 + 2*pin, eu.w2);
io_apic_write(apic, 0x10 + 2*pin, eu.w1);

2009-06-17 14:27:46

by Alan

Subject: Re: [PATCH]io_apic.c: fix compile warning

On Wed, 17 Jun 2009 22:25:20 +0800
"Figo.zhang" <[email protected]> wrote:

> fix compile warning:
> arch/x86/kernel/apic/io_apic.c: In function ‘ioapic_write_entry’:
> arch/x86/kernel/apic/io_apic.c:466: warning: ‘eu’ is used uninitialized in this function
> arch/x86/kernel/apic/io_apic.c:465: note: ‘eu’ was declared here

What compiler are you using. Current gcc correctly notices that there are
no uninitialized things to worry about ?

2009-06-17 14:29:29

by Figo.zhang

Subject: Re: [PATCH]io_apic.c: fix compile warning

On Wed, 2009-06-17 at 15:28 +0100, Alan Cox wrote:
> On Wed, 17 Jun 2009 22:25:20 +0800
> "Figo.zhang" <[email protected]> wrote:
>
> > fix compile warning:
> > arch/x86/kernel/apic/io_apic.c: In function ‘ioapic_write_entry’:
> > arch/x86/kernel/apic/io_apic.c:466: warning: ‘eu’ is used uninitialized in this function
> > arch/x86/kernel/apic/io_apic.c:465: note: ‘eu’ was declared here
>
> What compiler are you using. Current gcc correctly notices that there are
> no uninitialized things to worry about ?

hi Alan:
my gcc is:

[figo@myhost linux-2.6]$ gcc -v
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: ../configure --prefix=/usr --enable-shared
--enable-languages=c,c++,fortran,objc,obj-c++ --enable-threads=posix
--mandir=/usr/share/man --infodir=/usr/share/info --enable-__cxa_atexit
--disable-multilib --libdir=/usr/lib --libexecdir=/usr/lib
--enable-clocale=gnu --disable-libstdcxx-pch --with-tune=generic
Thread model: posix
gcc version 4.4.0 20090526 (prerelease) (GCC)
[figo@myhost linux-2.6]$



Best Regards,
Figo.zhang

2009-06-17 14:35:35

by Subrata Modak

Subject: Re: [PATCH]io_apic.c: fix compile warning

> On Wed, 17 Jun 2009 22:25:20 +0800
> "Figo.zhang" <[email protected]> wrote:
>
> > fix compile warning:
> > arch/x86/kernel/apic/io_apic.c: In function ‘ioapic_write_entry’:
> > arch/x86/kernel/apic/io_apic.c:466: warning: ‘eu’ is used uninitialized in this function
> > arch/x86/kernel/apic/io_apic.c:465: note: ‘eu’ was declared here
>
> What compiler are you using. Current gcc correctly notices that there are
> no uninitialized things to worry about ?

Even 4.4.0 and above reports this warning. Last time i remember it
generated somewhere around 70 such warnings. And, then you need to dig
down whether any of them will really introduce bug(s). Else, leave as it
is. It is more of a gcc problem rather than kernel.

Regards--
Subrata