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Date: Wed, 16 Jul 2014 20:50:38 -0400 From: Nick Krause <xerofoify@...il.com> To: Chris Metcalf <cmetcalf@...era.com> Cc: Paul Bolle <pebolle@...cali.nl>, Johannes Weiner <hannes@...xchg.org>, mhocko <mhocko@...e.cz>, Andrew Morton <akpm@...ux-foundation.org>, zlu <zlu@...era.com>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org> Subject: Re: [PATCH] title: no lookup_page for if statement On Mon, Jul 14, 2014 at 3:35 PM, Chris Metcalf <cmetcalf@...era.com> wrote: > On 7/14/2014 2:59 PM, Paul Bolle wrote: >> >> On Mon, 2014-07-14 at 14:49 -0400, Nicholas Krause wrote: >>> >>> >This patch removes the if define statement for page_lookup in order >>> >to remove a fix me of this not being defined as of yet. >>> > >>> >Signed-off-by: Nicholas Krause<xerofoify@...il.com> > > > Nicholas, you can't just enable this code; it will break the > build, since there is no lookup_address() symbol on tile. > > I'd like to encourage you to look for more substantive kinds of > changes to submit to LKML. This one and the last one (adding some > underscores to some obsolete symbols) both have ended up costing me > some time to look at and figure out what's actually going on, but > for no real value. I suspect there may be "janitor" tasks that > are more useful if you are looking for small starting points > (Google for "linux kernel janitors"). > > That said I'm going to go ahead and check in the following change > which actually does work, now that my attention has been drawn here. > > diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c > index 6c0571216a9d..7e884001ca6a 100644 > --- a/arch/tile/mm/fault.c > +++ b/arch/tile/mm/fault.c > @@ -513,17 +513,14 @@ no_context: > > bust_spinlocks(1); > > - /* FIXME: no lookup_address() yet */ > -#ifdef SUPPORT_LOOKUP_ADDRESS > - if (fault_num == INT_ITLB_MISS) { > - pte_t *pte = lookup_address(address); > + if (fault_num == INT_ITLB_MISS && address >= PAGE_OFFSET) { > + pte_t *pte = virt_to_kpte(address); > > - if (pte && pte_present(*pte) && !pte_exec_kernel(*pte)) > - pr_crit("kernel tried to execute" > - " non-executable page - exploit attempt?" > - " (uid: %d)\n", current->uid); > + if (pte && pte_present(*pte) && !pte_exec(*pte)) > + pr_crit("kernel tried to execute non-executable > page" > + " - exploit attempt? (uid: %d)\n", > + from_kuid(&init_user_ns, current_uid())); > } > -#endif > if (address < PAGE_SIZE) > pr_alert("Unable to handle kernel NULL pointer > dereference\n"); > else > > -- > Chris Metcalf, Tilera Corp. > http://www.tilera.com > Chris, Understood I screwed up here. I am doing other changes with build and warning errors. Plus some fix me issues that are simple. I will double check my patches and the code they are relating to more carefully. I should have asked you before writing this patch:(. Nick -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.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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