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Date: Wed, 27 Apr 2011 16:28:27 +0200
From: Aurelien Jarno <aurelien@aurel32.net>
Message-ID: <20110427142827.GC31605@volta.aurel32.net>
References: <1301847765-8203-1-git-send-email-weil@mail.berlios.de>
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Subject: Re: [Qemu-devel] [PATCH] darwin-user: Remove unneeded null pointer
 check
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To: Stefan Weil <weil@mail.berlios.de>
Cc: Blue Swirl <blauwirbel@gmail.com>, QEMU Developers <qemu-devel@nongnu.org>

On Sun, Apr 03, 2011 at 06:22:45PM +0200, Stefan Weil wrote:
> cppcheck reports this error:
> 
> commpage.c:223: error: Possible null pointer dereference:
> value - otherwise it is redundant to check if value is null at line 214
> 
> The null pointer check in line 214 is indeed not needed.
> If value were null, the code would crash in line 223.
> See do_compare_and_swap64 were for a reference.
> 
> Signed-off-by: Stefan Weil <weil@mail.berlios.de>
> ---
>  darwin-user/commpage.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)

Thanks, applied.

> diff --git a/darwin-user/commpage.c b/darwin-user/commpage.c
> index f6aa71e..cc29bdd 100644
> --- a/darwin-user/commpage.c
> +++ b/darwin-user/commpage.c
> @@ -211,7 +211,7 @@ void do_compare_and_swap32(void *cpu_env, int num)
>      uint32_t *value = (uint32_t*)((CPUX86State*)cpu_env)->regs[R_ECX];
>      DPRINTF("commpage: compare_and_swap32(%x,new,%p)\n", old, value);
>  
> -    if(value && old == tswap32(*value))
> +    if(old == tswap32(*value))
>      {
>          uint32_t new = ((CPUX86State*)cpu_env)->regs[R_EDX];
>          *value = tswap32(new);
> -- 
> 1.7.2.5
> 
> 
> 

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net