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Subject: Re: [PATCH 14/15] powerpc/watchpoint/xmon: Don't allow breakpoint
 overwriting
To:     Ravi Bangoria <ravi.bangoria@linux.ibm.com>, mpe@ellerman.id.au,
        mikey@neuling.org
Cc:     apopple@linux.ibm.com, paulus@samba.org, npiggin@gmail.com,
        naveen.n.rao@linux.vnet.ibm.com, peterz@infradead.org,
        jolsa@kernel.org, oleg@redhat.com, fweisbec@gmail.com,
        mingo@kernel.org, linuxppc-dev@lists.ozlabs.org,
        linux-kernel@vger.kernel.org
References: <20200309085806.155823-1-ravi.bangoria@linux.ibm.com>
 <20200309085806.155823-15-ravi.bangoria@linux.ibm.com>
From:   Christophe Leroy <christophe.leroy@c-s.fr>
Message-ID: <b6892b22-c521-207e-e5fd-ca66c774b314@c-s.fr>
Date:   Tue, 17 Mar 2020 12:10:39 +0100
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Le 09/03/2020 à 09:58, Ravi Bangoria a écrit :
> Xmon allows overwriting breakpoints because it's supported by only
> one dawr. But with multiple dawrs, overwriting becomes ambiguous
> or unnecessary complicated. So let's not allow it.

Could we drop this completely (I mean the functionnality, not the patch).

Christophe

> 
> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
> ---
>   arch/powerpc/xmon/xmon.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
> index 0ca0d29f99c6..ac18fe3e4295 100644
> --- a/arch/powerpc/xmon/xmon.c
> +++ b/arch/powerpc/xmon/xmon.c
> @@ -1381,6 +1381,10 @@ bpt_cmds(void)
>   			printf("Hardware data breakpoint not supported on this cpu\n");
>   			break;
>   		}
> +		if (dabr.enabled) {
> +			printf("Couldn't find free breakpoint register\n");
> +			break;
> +		}
>   		mode = 7;
>   		cmd = inchar();
>   		if (cmd == 'r')
>