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From: Andi Kleen <ak@linux.intel.com>
To: kan.liang@linux.intel.com
Cc: peterz@infradead.org, mingo@redhat.com,
	linux-kernel@vger.kernel.org, David.Laight@aculab.com
Subject: Re: [PATCH V2 2/3] perf/x86/intel/uncore: Record the size of mapped area
Date: Thu, 28 May 2020 06:29:08 -0700	[thread overview]
Message-ID: <20200528132908.GG611145@tassilo.jf.intel.com> (raw)
In-Reply-To: <1590671727-99311-2-git-send-email-kan.liang@linux.intel.com>

On Thu, May 28, 2020 at 06:15:26AM -0700, kan.liang@linux.intel.com wrote:
> -	box->io_addr = ioremap(addr, SNB_UNCORE_PCI_IMC_MAP_SIZE);
> +	if (!type->mmio_map_size) {
> +		pr_warn("perf uncore: Cannot ioremap for %s. Size of map area is 0.\n",
> +			type->name);
> +		return;
> +	}

Is that likely that the size is 0?

In any case you have to test the return value of ioremap. So I would rather
test the address for 0 than the size.

Similar in other code below.

I thought you were going to add a range check based on the size to the
actual access. Did I miss it in the patch?

-Andi

  reply	other threads:[~2020-05-28 13:29 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-28 13:15 [PATCH V2 1/3] perf/x86/intel/uncore: Fix oops when counting IMC uncore events on some TGL kan.liang
2020-05-28 13:15 ` [PATCH V2 2/3] perf/x86/intel/uncore: Record the size of mapped area kan.liang
2020-05-28 13:29   ` Andi Kleen [this message]
2020-05-28 13:44     ` Liang, Kan
2020-05-28 13:15 ` [PATCH V2 3/3] perf/x86/intel/uncore: Validate MMIO address before accessing kan.liang
2020-05-28 13:30   ` Andi Kleen
2020-05-28 13:46     ` Liang, Kan
2020-05-28 13:33   ` David Laight
2020-05-28 13:49     ` Liang, Kan
2020-05-28 14:02       ` Andi Kleen
2020-05-28 14:08         ` Liang, Kan

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