From: Peter Zijlstra <a.p.zijlstra@chello.nl> To: Ollie Wild <aaw@google.com> Cc: linux-kernel@vger.kernel.org, parisc-linux@lists.parisc-linux.org, Linus Torvalds <torvalds@osdl.org>, Arjan van de Ven <arjan@infradead.org>, Ingo Molnar <mingo@elte.hu>, linux-mm@kvack.org, Andrew Morton <akpm@osdl.org>, Andi Kleen <ak@muc.de>, linux-arch@vger.kernel.org, David Howells <dhowells@redhat.com> Subject: Re: Removing MAX_ARG_PAGES (request for comments/assistance) Date: Wed, 11 Oct 2006 15:14:20 +0200 [thread overview] Message-ID: <1160572460.2006.79.camel@taijtu> (raw) In-Reply-To: <65dd6fd50610101705t3db93a72sc0847cd120aa05d3@mail.gmail.com> On Tue, 2006-10-10 at 17:05 -0700, Ollie Wild wrote: > + vma->vm_flags &= ~VM_EXEC; > + // FIXME: Are the next two lines sufficient, or do I need to > + // do some additional magic? > + vma->vm_flags |= mm->def_flags; > + vma->vm_page_prot = protection_map[vma->vm_flags & 0x7]; Yeah, you'll need to change the PTEs for those pages you created by calling get_user_page() by calling an mprotect like function; perhaps something like: struct vm_area_struct *prev; unsigned long vm_flags = vma->vm_flags; s/vma->vm_flags/vm_flags/g err = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, vm_flags); BUG_ON(prev != vma); mprotect_fixup will then set the new protection on all PTEs and update vma->vm_flags and vma->vm_page_prot. > + /* Move stack pages down in memory. */ > + if (stack_shift) { > + // FIXME: Verify the shift is OK. > + What exactly are you wondering about? the call to move_vma looks sane to me > + /* This should be safe even with overlap because we > + * are shifting down. */ > + ret = move_vma(vma, vma->vm_start, > + vma->vm_end - vma->vm_start, > + vma->vm_end - vma->vm_start, > + vma->vm_start - stack_shift); > + if (ret & ~PAGE_MASK) { > + up_write(&mm->mmap_sem); > + return ret; > + } > }
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <a.p.zijlstra@chello.nl> To: Ollie Wild <aaw@google.com> Cc: linux-kernel@vger.kernel.org, parisc-linux@lists.parisc-linux.org, Linus Torvalds <torvalds@osdl.org>, Arjan van de Ven <arjan@infradead.org>, Ingo Molnar <mingo@elte.hu>, linux-mm@kvack.org, Andrew Morton <akpm@osdl.org>, Andi Kleen <ak@muc.de>, linux-arch@vger.kernel.org, David Howells <dhowells@redhat.com> Subject: Re: Removing MAX_ARG_PAGES (request for comments/assistance) Date: Wed, 11 Oct 2006 15:14:20 +0200 [thread overview] Message-ID: <1160572460.2006.79.camel@taijtu> (raw) In-Reply-To: <65dd6fd50610101705t3db93a72sc0847cd120aa05d3@mail.gmail.com> On Tue, 2006-10-10 at 17:05 -0700, Ollie Wild wrote: > + vma->vm_flags &= ~VM_EXEC; > + // FIXME: Are the next two lines sufficient, or do I need to > + // do some additional magic? > + vma->vm_flags |= mm->def_flags; > + vma->vm_page_prot = protection_map[vma->vm_flags & 0x7]; Yeah, you'll need to change the PTEs for those pages you created by calling get_user_page() by calling an mprotect like function; perhaps something like: struct vm_area_struct *prev; unsigned long vm_flags = vma->vm_flags; s/vma->vm_flags/vm_flags/g err = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, vm_flags); BUG_ON(prev != vma); mprotect_fixup will then set the new protection on all PTEs and update vma->vm_flags and vma->vm_page_prot. > + /* Move stack pages down in memory. */ > + if (stack_shift) { > + // FIXME: Verify the shift is OK. > + What exactly are you wondering about? the call to move_vma looks sane to me > + /* This should be safe even with overlap because we > + * are shifting down. */ > + ret = move_vma(vma, vma->vm_start, > + vma->vm_end - vma->vm_start, > + vma->vm_end - vma->vm_start, > + vma->vm_start - stack_shift); > + if (ret & ~PAGE_MASK) { > + up_write(&mm->mmap_sem); > + return ret; > + } > } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2006-10-11 13:14 UTC|newest] Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top 2006-10-11 0:05 Removing MAX_ARG_PAGES (request for comments/assistance) Ollie Wild 2006-10-11 8:00 ` Arjan van de Ven 2006-10-11 8:00 ` Arjan van de Ven 2006-10-11 17:13 ` Ollie Wild 2006-10-11 17:13 ` Ollie Wild 2006-10-11 17:13 ` [parisc-linux] " Ollie Wild 2006-10-11 8:00 ` Arjan van de Ven 2006-10-11 13:14 ` Peter Zijlstra 2006-10-11 13:14 ` Peter Zijlstra [this message] 2006-10-11 13:14 ` Peter Zijlstra 2006-10-11 21:48 ` Ollie Wild 2006-10-24 17:48 ` [parisc-linux] " Ollie Wild 2006-10-24 17:48 ` Ollie Wild 2006-10-24 17:48 ` Ollie Wild [not found] ` <1161712748.24143.54.camel@taijtu> 2006-10-24 18:47 ` Ollie Wild 2006-12-29 20:03 ` [patch] remove MAX_ARG_PAGES Ingo Molnar 2006-12-29 20:03 ` Ingo Molnar 2006-12-29 20:49 ` [parisc-linux] " Russell King 2006-12-29 20:49 ` Russell King 2006-12-29 20:49 ` Russell King 2006-12-29 21:23 ` Linus Torvalds 2006-12-29 21:23 ` Linus Torvalds 2006-12-29 22:20 ` [parisc-linux] " Ingo Molnar 2006-12-29 22:20 ` Ingo Molnar 2006-12-29 22:20 ` Ingo Molnar 2006-12-29 21:23 ` [parisc-linux] " Linus Torvalds 2006-12-29 21:57 ` Ingo Molnar 2006-12-29 21:57 ` Ingo Molnar 2006-12-29 21:57 ` Ingo Molnar 2007-01-01 6:51 ` Ollie Wild 2007-01-01 6:51 ` [parisc-linux] " Ollie Wild 2007-01-01 6:58 ` Ollie Wild 2007-01-01 6:58 ` Ollie Wild 2007-01-01 6:58 ` Ollie Wild 2007-01-01 17:28 ` [parisc-linux] " Pavel Machek 2007-01-01 17:28 ` Pavel Machek 2007-01-01 17:28 ` Pavel Machek 2006-12-29 20:03 ` [parisc-linux] " Ingo Molnar 2007-01-02 18:18 ` [parisc-linux] " David Howells 2007-01-02 18:18 ` David Howells 2007-01-02 18:18 ` David Howells 2006-10-11 21:48 ` [parisc-linux] Re: Removing MAX_ARG_PAGES (request for comments/assistance) Ollie Wild 2007-01-02 17:52 ` David Howells 2007-01-02 17:52 ` David Howells 2007-01-02 17:52 ` David Howells
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