Re: [PATCH 3/3] perf, x86, lbr: Demand proper privileges forPERF_SAMPLE_BRANCH_KERNEL

[Andi Kleen]

On Fri, May 03, 2013 at 02:11:25PM +0200, Peter Zijlstra wrote:
> We should always have proper privileges when requesting kernel data.
> 
> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>

Acked-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

> --- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
> +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
> @@ -318,8 +318,11 @@ static void intel_pmu_setup_sw_lbr_filte
>  	if (br_type & PERF_SAMPLE_BRANCH_USER)
>  		mask |= X86_BR_USER;
>  
> -	if (br_type & PERF_SAMPLE_BRANCH_KERNEL)
> +	if (br_type & PERF_SAMPLE_BRANCH_KERNEL) {
> +		if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
> +			return -EACCES;
>  		mask |= X86_BR_KERNEL;
> +	}
>  
>  	/* we ignore BRANCH_HV here */
>  
> 
> 

-- 
ak@xxxxxxxxxxxxxxx -- Speaking for myself only
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