Messages in this thread |  | | | Subject | Re: [PATCH] Ensure that walk_page_range()'s start and end are page-aligned | | Date | Fri, 10 Feb 2012 21:13:07 +0100 | | From | "Michal Nazarewicz" <> |
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On Fri, 10 Feb 2012 20:57:31 +0100, Dan Smith <danms@us.ibm.com> wrote: > MN> Commit message says about walk_pte_range() but commit changes > MN> walk_page_range(). > > Yep, the issue occurs in walk_pte_range().
OK, it wasn't immediately obvious for me that while loop in walk_page_range() will actually recover if arguments are not aligned (since pgd_addr_end() caps returned value).
> The goal was to ensure that > the external interface to it (which is walk_page_range()) does the check > and avoids doing the walk entirely. I think the expectation is that > walk_page_range() is used on aligned addresses. If we put the check in > walk_pte_range() then only walks with a pte_entry handler would fail on > unaligned addresses, which is potentially confusing. > > MN> So why not change the condition to addr < end? > > That would work, of course, but seems sloppier and less precise. The > existing code was clearly written expecting to walk aligned addresses.
Fair enough.
-- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michał “mina86” Nazarewicz (o o) ooo +----<email/xmpp: mpn@google.com>--------------ooO--(_)--Ooo-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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