Messages in this thread | | | Date | Thu, 29 Nov 2007 01:05:31 +0100 | From | "J.A. Magallón" <> | Subject | void* arithmnetic |
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Hi all...
Since begin of the ages the build of the nvidia driver says things like this:
include/asm/compat.h:210: warning: pointer of type 'void *' used in arithmetic
There are several of this warnings. The code in question for this example is:
static __inline__ void __user *compat_alloc_user_space(long len) { struct pt_regs *regs = task_pt_regs(current); return (void __user *)regs->rsp - len; }
As this is dealing with mem blocks, I suppose it's counting in bytes, so we could do something like:
return (void __user *)((u8*)regs->rsp - len);
so the arithmetic knows how to inc/dec for each unity... I think the warning is correct and that void* arithmetic is undefined in C, isn't it ?
TIA
-- J.A. Magallon <jamagallon()ono!com> \ Software is like sex: \ It's better when it's free Mandriva Linux release 2008.1 (Cooker) for i586 Linux 2.6.23-jam01 (gcc 4.2.2 20070909 (4.2.2-0.RC.1mdv2008.0)) SMP PREEMPT 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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