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SubjectRe: [PATCH 3/5] perf_counter: rework ioctl()s
Date
On Friday 08 May 2009, Peter Zijlstra wrote:
> -#define PERF_COUNTER_IOC_ENABLE                _IO ('$', 0)
> -#define PERF_COUNTER_IOC_DISABLE       _IO ('$', 1)
> +#define PERF_COUNTER_IOC_ENABLE                _IOW('$', 0, u32)
> +#define PERF_COUNTER_IOC_DISABLE       _IOW('$', 1, u32)
>  #define PERF_COUNTER_IOC_REFRESH       _IOW('$', 2, u32)
> -#define PERF_COUNTER_IOC_RESET         _IO ('$', 3)
> +#define PERF_COUNTER_IOC_RESET         _IOW('$', 3, u32)

These ioctl definitions look malformed:
_IOW('$', 0, u32) means that the ioctl will read a u32 in user
space pointed to by (u32 __user *)arg, while what perf_ioctl
actually does is cast arg to a u32. Moreover, exported headers
should use __u32 instead of u32.

PERF_COUNTER_IOC_REFRESH apparently was broken already, this
patch also breaks the other definitions.

Arnd <><
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