From: Michal Hocko <mhocko@kernel.org>
To: Qian Cai <cai@lca.pw>
Cc: akpm@linux-foundation.org, osalvador@suse.de,
catalin.marinas@arm.com, vbabka@suse.cz, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] mm/hotplug: invalid PFNs from pfn_to_online_page()
Date: Tue, 22 Jan 2019 07:58:18 +0100 [thread overview]
Message-ID: <20190122065818.GA4087@dhcp22.suse.cz> (raw)
In-Reply-To: <20190121212747.23029-1-cai@lca.pw>
On Mon 21-01-19 16:27:47, Qian Cai wrote:
[...]
Sorry to miss this before but you want to
> +#define pfn_to_online_page(pfn) \
> +({ \
> + struct page *___page = NULL; \
unsigned long ___pfn = pfn;
> + unsigned long ___nr = pfn_to_section_nr(pfn); \
pfn_to_section_nr(___pfn);
> + \
> + if (___nr < NR_MEM_SECTIONS && online_section_nr(___nr) && \
> + pfn_valid_within(pfn)) \
pfn_valid_within(___pfn))
> + ___page = pfn_to_page(pfn); \
> + ___page; \
> })
to prevent from issues when pfn expression has side effects.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2019-01-22 6:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-21 21:27 Qian Cai
2019-01-22 6:58 ` Michal Hocko [this message]
2019-01-22 10:46 ` Oscar Salvador
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