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2008-07-12Merge branch 'linus' into x86/coreIngo Molnar
Conflicts: arch/x86/mm/ioremap.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-10slub: Fix use-after-preempt of per-CPU data structureDmitry Adamushko
Vegard Nossum reported a crash in kmem_cache_alloc(): BUG: unable to handle kernel paging request at da87d000 IP: [<c01991c7>] kmem_cache_alloc+0xc7/0xe0 *pde = 28180163 *pte = 1a87d160 Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC Pid: 3850, comm: grep Not tainted (2.6.26-rc9-00059-gb190333 #5) EIP: 0060:[<c01991c7>] EFLAGS: 00210203 CPU: 0 EIP is at kmem_cache_alloc+0xc7/0xe0 EAX: 00000000 EBX: da87c100 ECX: 1adad71a EDX: 6b6b6b6b ESI: 00200282 EDI: da87d000 EBP: f60bfe74 ESP: f60bfe54 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 and analyzed it: "The register %ecx looks innocent but is very important here. The disassembly: mov %edx,%ecx shr $0x2,%ecx rep stos %eax,%es:(%edi) <-- the fault So %ecx has been loaded from %edx... which is 0x6b6b6b6b/POISON_FREE. (0x6b6b6b6b >> 2 == 0x1adadada.) %ecx is the counter for the memset, from here: memset(object, 0, c->objsize); i.e. %ecx was loaded from c->objsize, so "c" must have been freed. Where did "c" come from? Uh-oh... c = get_cpu_slab(s, smp_processor_id()); This looks like it has very much to do with CPU hotplug/unplug. Is there a race between SLUB/hotplug since the CPU slab is used after it has been freed?" Good analysis. Yeah, it's possible that a caller of kmem_cache_alloc() -> slab_alloc() can be migrated on another CPU right after local_irq_restore() and before memset(). The inital cpu can become offline in the mean time (or a migration is a consequence of the CPU going offline) so its 'kmem_cache_cpu' structure gets freed ( slab_cpuup_callback). At some point of time the caller continues on another CPU having an obsolete pointer... Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Reported-by: Vegard Nossum <vegard.nossum@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-08mm, generic, x86 boot: more tweaks to hex prints of some pfn addressesPaul Jackson
Fix some problems with (and applies on top of) a previous patch: x86 boot: show pfn addresses in hex not decimal in some kernel info printks Primarily change "0x%8lx" format, which displays with a right aligned space filled hex number (spaces between the "0x" prefix and the number), into "%0#10lx" format, which zero fills instead of space fills, and which uses the printf flag '#' to request the "0x" prefix instead of hard coding it. Also replace some other "0x%lx" formats with "%#lx", making use of the '#' printf flag again. Signed-off-by: Paul Jackson <pj@sgi.com> Cc: "Yinghai Lu" <yhlu.kernel@gmail.com> Cc: "Jack Steiner" <steiner@sgi.com> Cc: "Mike Travis" <travis@sgi.com> Cc: "Huang Cc: Ying" <ying.huang@intel.com> Cc: "Andi Kleen" <andi@firstfloor.org> Cc: "Andrew Morton" <akpm@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08x86 boot: more consistently use type int for node idsPaul Jackson
Everywhere I look, node id's are of type 'int', except in this one case, which has 'unsigned long'. Change this one to 'int' as well. There is nothing special about the way this variable 'nid' is used in this routine to justify using an unusual type here. Signed-off-by: Paul Jackson <pj@sgi.com> Cc: "Yinghai Lu" <yhlu.kernel@gmail.com> Cc: "Jack Steiner" <steiner@sgi.com> Cc: "Mike Travis" <travis@sgi.com> Cc: "Huang Cc: Ying" <ying.huang@intel.com> Cc: "Andi Kleen" <andi@firstfloor.org> Cc: "Andrew Morton" <akpm@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08x86 boot: show pfn addresses in hex not decimal in some kernel info printksPaul Jackson
Page frame numbers (the portion of physical addresses above the low order page offsets) are displayed in several kernel debug and info prints in decimal, not hex. Decimal addresse are unreadable. Use hex. Signed-off-by: Paul Jackson <pj@sgi.com> Cc: "Yinghai Lu" <yhlu.kernel@gmail.com> Cc: "Jack Steiner" <steiner@sgi.com> Cc: "Mike Travis" <travis@sgi.com> Cc: "Huang Cc: Ying" <ying.huang@intel.com> Cc: "Andi Kleen" <andi@firstfloor.org> Cc: "Andrew Morton" <akpm@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08RFC x86: try to remove arch_get_ram_rangeYinghai Lu
want to remove arch_get_ram_range, and use early_node_map instead. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08Merge branch 'x86/mpparse' into x86/develIngo Molnar
Conflicts: arch/x86/Kconfig arch/x86/kernel/io_apic_32.c arch/x86/kernel/setup_64.c arch/x86/mm/init_32.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08x86, mm: use add_highpages_with_active_regions() for high pages init v2Yinghai Lu
use early_node_map to init high pages, so we can remove page_is_ram() and page_is_reserved_early() in the big loop with add_one_highpage also remove page_is_reserved_early(), it is not needed anymore. v2: fix the build of other platforms Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08x86: replace shrink_active_range() with remove_active_range()Yinghai Lu
in case we have kva before ramdisk on a node, we still need to use those ranges. v2: reserve_early kva ram area, in case there are holes in highmem, to avoid those area could be treat as free high pages. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08Merge branch 'linus' into tmp.x86.mpparse.newIngo Molnar
2008-07-08Merge branches 'x86/numa-fixes', 'x86/apic', 'x86/apm', 'x86/bitops', ↵Ingo Molnar
'x86/build', 'x86/cleanups', 'x86/cpa', 'x86/cpu', 'x86/defconfig', 'x86/gart', 'x86/i8259', 'x86/intel', 'x86/irqstats', 'x86/kconfig', 'x86/ldt', 'x86/mce', 'x86/memtest', 'x86/pat', 'x86/ptemask', 'x86/resumetrace', 'x86/threadinfo', 'x86/timers', 'x86/vdso' and 'x86/xen' into x86/devel
2008-07-04mempolicy: mask off internal flags for userspace APIDavid Rientjes
Flags considered internal to the mempolicy kernel code are stored as part of the "flags" member of struct mempolicy. Before exposing a policy type to userspace via get_mempolicy(), these internal flags must be masked. Flags exposed to userspace, however, should still be returned to the user. Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04get_user_pages(): fix possible page leak on oomOleg Nesterov
get_user_pages() must not return the error when i != 0. When pages != NULL we have i get_page()'ed pages. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04mm: dirty page accounting vs VM_MIXEDMAPPeter Zijlstra
Dirty page accounting accurately measures the amound of dirty pages in writable shared mappings by mapping the pages RO (as indicated by vma_wants_writenotify). We then trap on first write and call set_page_dirty() on the page, after which we map the page RW and continue execution. When we launder dirty pages, we call clear_page_dirty_for_io() which clears both the dirty flag, and maps the page RO again before we start writeout so that the story can repeat itself. vma_wants_writenotify() excludes VM_PFNMAP on the basis that we cannot do the regular dirty page stuff on raw PFNs and the memory isn't going anywhere anyway. The recently introduced VM_MIXEDMAP mixes both !pfn_valid() and pfn_valid() pages in a single mapping. We can't do dirty page accounting on !pfn_valid() pages as stated above, and mapping them RO causes them to be COW'ed on write, which breaks VM_SHARED semantics. Excluding VM_MIXEDMAP in vma_wants_writenotify() would mean we don't do the regular dirty page accounting for the pfn_valid() pages, which would bring back all the head-aches from inaccurate dirty page accounting. So instead, we let the !pfn_valid() pages get mapped RO, but fix them up unconditionally in the fault path. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Hugh Dickins <hugh@veritas.com> Cc: "Jared Hulbert" <jaredeh@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04Christoph has movedChristoph Lameter
Remove all clameter@sgi.com addresses from the kernel tree since they will become invalid on June 27th. Change my maintainer email address for the slab allocators to cl@linux-foundation.org (which will be the new email address for the future). Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: slub: Do not use 192 byte sized cache if minimum alignment is 128 byte
2008-07-03Do not overwrite nr_zones on !NUMA when initialising zlcache_ptrMel Gorman
The non-NUMA case of build_zonelist_cache() would initialize the zlcache_ptr for both node_zonelists[] to NULL. Which is problematic, since non-NUMA only has a single node_zonelists[] entry, and trying to zero the non-existent second one just overwrote the nr_zones field instead. As kswapd uses this value to determine what reclaim work is necessary, the result is that kswapd never reclaims. This causes processes to stall frequently in low-memory situations as they always direct reclaim. This patch initialises zlcache_ptr correctly. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Tested-by: Dan Williams <dan.j.williams@intel.com> [ Simplified patch a bit ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-03slub: Do not use 192 byte sized cache if minimum alignment is 128 byteChristoph Lameter
The 192 byte cache is not necessary if we have a basic alignment of 128 byte. If it would be used then the 192 would be aligned to the next 128 byte boundary which would result in another 256 byte cache. Two 256 kmalloc caches cause sysfs to complain about a duplicate entry. MIPS needs 128 byte aligned kmalloc caches and spits out warnings on boot without this patch. Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-06-25mm: add a ptep_modify_prot transaction abstractionJeremy Fitzhardinge
This patch adds an API for doing read-modify-write updates to a pte's protection bits which may race against hardware updates to the pte. After reading the pte, the hardware may asynchonously set the accessed or dirty bits on a pte, which would be lost when writing back the modified pte value. The existing technique to handle this race is to use ptep_get_and_clear() atomically fetch the old pte value and clear it in memory. This has the effect of marking the pte as non-present, which will prevent the hardware from updating its state. When the new value is written back, the pte will be present again, and the hardware can resume updating the access/dirty flags. When running in a virtualized environment, pagetable updates are relatively expensive, since they generally involve some trap into the hypervisor. To mitigate the cost of these updates, we tend to batch them. However, because of the atomic nature of ptep_get_and_clear(), it is inherently non-batchable. This new interface allows batching by giving the underlying implementation enough information to open a transaction between the read and write phases: ptep_modify_prot_start() returns the current pte value, and puts the pte entry into a state where either the hardware will not update the pte, or if it does, the updates will be preserved on commit. ptep_modify_prot_commit() writes back the updated pte, makes sure that any hardware updates made since ptep_modify_prot_start() are preserved. ptep_modify_prot_start() and _commit() must be exactly paired, and used while holding the appropriate pte lock. They do not protect against other software updates of the pte in any way. The current implementations of ptep_modify_prot_start and _commit are functionally unchanged from before: _start() uses ptep_get_and_clear() fetch the pte and zero the entry, preventing any hardware updates. _commit() simply writes the new pte value back knowing that the hardware has not updated the pte in the meantime. The only current user of this interface is mprotect Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-23mm: fix race in COW logicNick Piggin
There is a race in the COW logic. It contains a shortcut to avoid the COW and reuse the page if we have the sole reference on the page, however it is possible to have two racing do_wp_page()ers with one causing the other to mistakenly believe it is safe to take the shortcut when it is not. This could lead to data corruption. Process 1 and process2 each have a wp pte of the same anon page (ie. one forked the other). The page's mapcount is 2. Then they both attempt to write to it around the same time... proc1 proc2 thr1 proc2 thr2 CPU0 CPU1 CPU3 do_wp_page() do_wp_page() trylock_page() can_share_swap_page() load page mapcount (==2) reuse = 0 pte unlock copy page to new_page pte lock page_remove_rmap(page); trylock_page() can_share_swap_page() load page mapcount (==1) reuse = 1 ptep_set_access_flags (allow W) write private key into page read from page ptep_clear_flush() set_pte_at(pte of new_page) Fix this by moving the page_remove_rmap of the old page after the pte clear and flush. Potentially the entire branch could be moved down here, but in order to stay consistent, I won't (should probably move all the *_mm_counter stuff with one patch). Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Hugh Dickins <hugh@veritas.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-23Fix ZERO_PAGE breakage with vmwareLinus Torvalds
Commit 89f5b7da2a6bad2e84670422ab8192382a5aeb9f ("Reinstate ZERO_PAGE optimization in 'get_user_pages()' and fix XIP") broke vmware, as reported by Jeff Chua: "This broke vmware 6.0.4. Jun 22 14:53:03.845: vmx| NOT_IMPLEMENTED /build/mts/release/bora-93057/bora/vmx/main/vmmonPosix.c:774" and the reason seems to be that there's an old bug in how we handle do FOLL_ANON on VM_SHARED areas in get_user_pages(), but since it only triggered if the whole page table was missing, nobody had apparently hit it before. The recent changes to 'follow_page()' made the FOLL_ANON logic trigger not just for whole missing page tables, but for individual pages as well, and exposed this problem. This fixes it by making the test for when FOLL_ANON is used more careful, and also makes the code easier to read and understand by moving the logic to a separate inline function. Reported-and-tested-by: Jeff Chua <jeff.chua.linux@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-21Slab: Fix memory leak in fallback_alloc()Christoph Lameter
The zonelist patches caused the loop that checks for available objects in permitted zones to not terminate immediately. One object per zone per allocation may be allocated and then abandoned. Break the loop when we have successfully allocated one object. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-21Add return value to reserve_bootmem_node()Bernhard Walle
This patch changes the function reserve_bootmem_node() from void to int, returning -ENOMEM if the allocation fails. This fixes a build problem on x86 with CONFIG_KEXEC=y and CONFIG_NEED_MULTIPLE_NODES=y Signed-off-by: Bernhard Walle <bwalle@suse.de> Reported-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-20Reinstate ZERO_PAGE optimization in 'get_user_pages()' and fix XIPLinus Torvalds
KAMEZAWA Hiroyuki and Oleg Nesterov point out that since the commit 557ed1fa2620dc119adb86b34c614e152a629a80 ("remove ZERO_PAGE") removed the ZERO_PAGE from the VM mappings, any users of get_user_pages() will generally now populate the VM with real empty pages needlessly. We used to get the ZERO_PAGE when we did the "handle_mm_fault()", but since fault handling no longer uses ZERO_PAGE for new anonymous pages, we now need to handle that special case in follow_page() instead. In particular, the removal of ZERO_PAGE effectively removed the core file writing optimization where we would skip writing pages that had not been populated at all, and increased memory pressure a lot by allocating all those useless newly zeroed pages. This reinstates the optimization by making the unmapped PTE case the same as for a non-existent page table, which already did this correctly. While at it, this also fixes the XIP case for follow_page(), where the caller could not differentiate between the case of a page that simply could not be used (because it had no "struct page" associated with it) and a page that just wasn't mapped. We do that by simply returning an error pointer for pages that could not be turned into a "struct page *". The error is arbitrarily picked to be EFAULT, since that was what get_user_pages() already used for the equivalent IO-mapped page case. [ Also removed an impossible test for pte_offset_map_lock() failing: that's not how that function works ] Acked-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12pagemap: pass mm into pagewalkersDave Hansen
We need this at least for huge page detection for now, because powerpc needs the vm_area_struct to be able to determine whether a virtual address is referring to a huge page (its pmd_huge() doesn't work). It might also come in handy for some of the other users. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12mm: fix incorrect variable type in do_try_to_free_pages()kosaki.motohiro@jp.fujitsu.com
"Smarter retry of costly-order allocations" patch series change behaver of do_try_to_free_pages(). But unfortunately ret variable type was unchanged. Thus an overflow is possible. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12nommu: Correct kobjsize() page validity checks.Paul Mundt
This implements a few changes on top of the recent kobjsize() refactoring introduced by commit 6cfd53fc03670c7a544a56d441eb1a6cc800d72b. As Christoph points out: virt_to_head_page cannot return NULL. virt_to_page also does not return NULL. pfn_valid() needs to be used to figure out if a page is valid. Otherwise the page struct reference that was returned may have PageReserved() set to indicate that it is not a valid page. As discussed further in the thread, virt_addr_valid() is the preferable way to validate the object pointer in this case. In addition to fixing up the reserved page case, it also has the benefit of encapsulating the hack introduced by commit 4016a1390d07f15b267eecb20e76a48fd5c524ef on the impacted platforms, allowing us to get rid of the extra checking in kobjsize() for the platforms that don't perform this type of bizarre memory_end abuse (every nommu platform that isn't blackfin). If blackfin decides to get in line with every other platform and use PageReserved for the DMA pages in question, kobjsize() will also continue to work fine. It also turns out that compound_order() will give us back 0-order for non-head pages, so we can get rid of the PageCompound check and just use compound_order() directly. Clean that up while we're at it. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Reviewed-by: Christoph Lameter <clameter@sgi.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-10mm, x86: shrink_active_range() should check allYinghai Lu
Now we are using register_e820_active_regions() instead of add_active_range() directly. So end_pfn could be different between the value in early_node_map to node_end_pfn. So we need to make shrink_active_range() smarter. shrink_active_range() is a generic MM function in mm/page_alloc.c but it is only used on 32-bit x86. Should we move it back to some file in arch/x86? Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-09mm: Minor clean-up of page flags in mm/page_alloc.cRuss Anderson
Minor source code cleanup of page flags in mm/page_alloc.c. Move the definition of the groups of bits to page-flags.h. The purpose of this clean up is that the next patch will conditionally add a page flag to the groups. Doing that in a header file is cleaner than adding #ifdefs to the C code. Signed-off-by: Russ Anderson <rja@sgi.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06nommu: fix kobjsize() for SLOB and SLUBPaul Mundt
kobjsize() has been abusing page->index as a method for sorting out compound order, which blows up both for page cache pages, and SLOB's reuse of the index in struct slob_page. Presently we are not able to accurately size arbitrary pointers that don't come from kmalloc(), so the best we can do is sort out the compound order from the head page if it's a compound page, or default to 0-order if it's impossible to ksize() the object. Obviously this leaves quite a bit to be desired in terms of object sizing accuracy, but the behaviour is unchanged over the existing implementation, while fixing the page->index oopses originally reported here: http://marc.info/?l=linux-mm&m=121127773325245&w=2 Accuracy could also be improved by having SLUB and SLOB both set PG_slab on ksizeable pages, rather than just handling the __GFP_COMP cases irregardless of the PG_slab setting, as made possibly with Pekka's patches: http://marc.info/?l=linux-kernel&m=121139439900534&w=2 http://marc.info/?l=linux-kernel&m=121139440000537&w=2 http://marc.info/?l=linux-kernel&m=121139440000540&w=2 This is primarily a bugfix for nommu systems for 2.6.26, with the aim being to gradually kill off kobjsize() and its particular brand of object abuse entirely. Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06brk: make sys_brk() honor COMPAT_BRK when computing lower boundJiri Kosina
Fix a regression introduced by commit 4cc6028d4040f95cdb590a87db478b42b8be0508 Author: Jiri Kosina <jkosina@suse.cz> Date: Wed Feb 6 22:39:44 2008 +0100 brk: check the lower bound properly The check in sys_brk() on minimum value the brk might have must take CONFIG_COMPAT_BRK setting into account. When this option is turned on (i.e. we support ancient legacy binaries, e.g. libc5-linked stuff), the lower bound on brk value is mm->end_code, otherwise the brk start is allowed to be arbitrarily shifted. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06hugetlb: fix lockdep errorNick Piggin
============================================= [ INFO: possible recursive locking detected ] 2.6.26-rc4 #30 --------------------------------------------- heap-overflow/2250 is trying to acquire lock: (&mm->page_table_lock){--..}, at: [<c0000000000cf2e8>] .copy_hugetlb_page_range+0x108/0x280 but task is already holding lock: (&mm->page_table_lock){--..}, at: [<c0000000000cf2dc>] .copy_hugetlb_page_range+0xfc/0x280 other info that might help us debug this: 3 locks held by heap-overflow/2250: #0: (&mm->mmap_sem){----}, at: [<c000000000050e44>] .dup_mm+0x134/0x410 #1: (&mm->mmap_sem/1){--..}, at: [<c000000000050e54>] .dup_mm+0x144/0x410 #2: (&mm->page_table_lock){--..}, at: [<c0000000000cf2dc>] .copy_hugetlb_page_range+0xfc/0x280 stack backtrace: Call Trace: [c00000003b2774e0] [c000000000010ce4] .show_stack+0x74/0x1f0 (unreliable) [c00000003b2775a0] [c0000000003f10e0] .dump_stack+0x20/0x34 [c00000003b277620] [c0000000000889bc] .__lock_acquire+0xaac/0x1080 [c00000003b277740] [c000000000089000] .lock_acquire+0x70/0xb0 [c00000003b2777d0] [c0000000003ee15c] ._spin_lock+0x4c/0x80 [c00000003b277870] [c0000000000cf2e8] .copy_hugetlb_page_range+0x108/0x280 [c00000003b277950] [c0000000000bcaa8] .copy_page_range+0x558/0x790 [c00000003b277ac0] [c000000000050fe0] .dup_mm+0x2d0/0x410 [c00000003b277ba0] [c000000000051d24] .copy_process+0xb94/0x1020 [c00000003b277ca0] [c000000000052244] .do_fork+0x94/0x310 [c00000003b277db0] [c000000000011240] .sys_clone+0x60/0x80 [c00000003b277e30] [c0000000000078c4] .ppc_clone+0x8/0xc Fix is the same way that mm/memory.c copy_page_range does the lockdep annotation. Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Adam Litke <agl@us.ibm.com> Acked-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-03x86, numa, 32-bit: print out debug info on all kvasYinghai Lu
also fix the print out of node_remap_end_vaddr Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-26Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: slub: ksize() abuse checks slob: Fix to return wrong pointer
2008-05-24memory hotplug: fix early allocation handlingHeiko Carstens
Trying to add memory via add_memory() from within an initcall function results in bootmem alloc of 163840 bytes failed! Kernel panic - not syncing: Out of memory This is caused by zone_wait_table_init() which uses system_state to decide if it should use the bootmem allocator or not. When initcalls are handled the system_state is still SYSTEM_BOOTING but the bootmem allocator doesn't work anymore. So the allocation will fail. To fix this use slab_is_available() instead as indicator like we do it everywhere else. [akpm@linux-foundation.org: coding-style fix] Reviewed-by: Andy Whitcroft <apw@shadowen.org> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24zonelists: handle a node zonelist with no applicable entriesAndy Whitcroft
When booting 2.6.26-rc3 on a multi-node x86_32 numa system we are seeing panics when trying node local allocations: BUG: unable to handle kernel NULL pointer dereference at 0000034c IP: [<c1042507>] get_page_from_freelist+0x4a/0x18e *pdpt = 00000000013a7001 *pde = 0000000000000000 Oops: 0000 [#1] SMP Modules linked in: Pid: 0, comm: swapper Not tainted (2.6.26-rc3-00003-g5abc28d #82) EIP: 0060:[<c1042507>] EFLAGS: 00010282 CPU: 0 EIP is at get_page_from_freelist+0x4a/0x18e EAX: c1371ed8 EBX: 00000000 ECX: 00000000 EDX: 00000000 ESI: f7801180 EDI: 00000000 EBP: 00000000 ESP: c1371ec0 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 Process swapper (pid: 0, ti=c1370000 task=c12f5b40 task.ti=c1370000) Stack: 00000000 00000000 00000000 00000000 000612d0 000412d0 00000000 000412d0 f7801180 f7c0101c f7c01018 c10426e4 f7c01018 00000001 00000044 00000000 00000001 c12f5b40 00000001 00000010 00000000 000412d0 00000286 000412d0 Call Trace: [<c10426e4>] __alloc_pages_internal+0x99/0x378 [<c10429ca>] __alloc_pages+0x7/0x9 [<c105e0e8>] kmem_getpages+0x66/0xef [<c105ec55>] cache_grow+0x8f/0x123 [<c105f117>] ____cache_alloc_node+0xb9/0xe4 [<c105f427>] kmem_cache_alloc_node+0x92/0xd2 [<c122118c>] setup_cpu_cache+0xaf/0x177 [<c105e6ca>] kmem_cache_create+0x2c8/0x353 [<c13853af>] kmem_cache_init+0x1ce/0x3ad [<c13755c5>] start_kernel+0x178/0x1ee This occurs when we are scanning the zonelists looking for a ZONE_NORMAL page. In this system there is only ZONE_DMA and ZONE_NORMAL memory on node 0, all other nodes are mapped above 4GB physical. Here is a dump of the zonelists from this system: zonelists pgdat=c1400000 0: c14006c0:2 f7c006c0:2 f7e006c0:2 c1400360:1 c1400000:0 1: c14006c0:2 c1400360:1 c1400000:0 zonelists pgdat=f7c00000 0: f7c006c0:2 f7e006c0:2 c14006c0:2 c1400360:1 c1400000:0 1: f7c006c0:2 zonelists pgdat=f7e00000 0: f7e006c0:2 c14006c0:2 f7c006c0:2 c1400360:1 c1400000:0 1: f7e006c0:2 When performing a node local allocation we call get_page_from_freelist() looking for a page. It in turn calls first_zones_zonelist() which returns a preferred_zone. Where there are no applicable zones this will be NULL. However we use this unconditionally, leading to this panic. Where there are no applicable zones there is no possibility of a successful allocation, so simply fail the allocation. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24mm: fix atomic_t overflow in vmAlan Cox
The atomic_t type is 32bit but a 64bit system can have more than 2^32 pages of virtual address space available. Without this we overflow on ludicrously large mappings Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24mm: don't drop a partial page in a zone's memory map sizeJohannes Weiner
In a zone's present pages number, account for all pages occupied by the memory map, including a partial. Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24mm: allow pfnmap ->fault()sNick Piggin
Take out an assertion to allow ->fault handlers to service PFNMAP regions. This is required to reimplement .nopfn handlers with .fault handlers and subsequently remove nopfn. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Jes Sorensen <jes@sgi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-22slub: ksize() abuse checksPekka Enberg
Add a WARN_ON for pages that don't have PageSlab nor PageCompound set to catch the worst abusers of ksize() in the kernel. Acked-by: Christoph Lameter <clameter@sgi.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-05-20mm: bdi: fix race in bdi_class device creationGreg Kroah-Hartman
There is a race from when a device is created with device_create() and then the drvdata is set with a call to dev_set_drvdata() in which a sysfs file could be open, yet the drvdata will be NULL, causing all sorts of bad things to happen. This patch fixes the problem by using the new function, device_create_vargs(). Many thanks to Arthur Jones <ajones@riverbed.com> for reporting the bug, and testing patches out. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Arthur Jones <ajones@riverbed.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-05-19slob: Fix to return wrong pointerMinChan Kim
Although slob_alloc return NULL, __kmalloc_node returns NULL + align. Because align always can be changed, it is very hard for debugging problem of no page if it don't return NULL. We have to return NULL in case of no page. [penberg@cs.helsinki.fi: fix formatting as suggested by Matt.] Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: MinChan Kim <minchan.kim@gmail.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-05-14memory_hotplug: always initialize pageblock bitmapHeiko Carstens
Trying to online a new memory section that was added via memory hotplug sometimes results in crashes when the new pages are added via __free_page. Reason for that is that the pageblock bitmap isn't initialized and hence contains random stuff. That means that get_pageblock_migratetype() returns also random stuff and therefore list_add(&page->lru, &zone->free_area[order].free_list[migratetype]); in __free_one_page() tries to do a list_add to something that isn't even necessarily a list. This happens since 86051ca5eaf5e560113ec7673462804c54284456 ("mm: fix usemap initialization") which makes sure that the pageblock bitmap gets only initialized for pages present in a zone. Unfortunately for hot-added memory the zones "grow" after the memmap and the pageblock memmap have been initialized. Which means that the new pages have an unitialized bitmap. To solve this the calls to grow_zone_span() and grow_pgdat_span() are moved to __add_zone() just before the initialization happens. The patch also moves the two functions since __add_zone() is the only caller and I didn't want to add a forward declaration. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14mprotect: prevent alteration of the PAT bitsVenki Pallipadi
There is a defect in mprotect, which lets the user change the page cache type bits by-passing the kernel reserve_memtype and free_memtype wrappers. Fix the problem by not letting mprotect change the PAT bits. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14memory_hotplug: check for walk_memory_resource() failure in online_pages()Geoff Levand
Add a check to online_pages() to test for failure of walk_memory_resource(). This fixes a condition where a failure of walk_memory_resource() can lead to online_pages() returning success without the requested pages being onlined. Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Keith Mannthey <kmannth@us.ibm.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14memory hotplug: memmap_init_zone called twiceHeiko Carstens
__add_zone calls memmap_init_zone twice if memory gets attached to an empty zone. Once via init_currently_empty_zone and once explictly right after that call. Looks like this is currently not a bug, however the call is superfluous and might lead to subtle bugs if memmap_init_zone gets changed. So make sure it is called only once. Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14mm: fix infinite loop in filemap_faultMiklos Szeredi
filemap_fault will go into an infinite loop if ->readpage() fails asynchronously. AFAICS the bug was introduced by this commit, which removed the wait after the final readpage: commit d00806b183152af6d24f46f0c33f14162ca1262a Author: Nick Piggin <npiggin@suse.de> Date: Thu Jul 19 01:46:57 2007 -0700 mm: fix fault vs invalidate race for linear mappings Fix by reintroducing the wait_on_page_locked() after ->readpage() to make sure the page is up-to-date before jumping back to the beginning of the function. I've noticed this while testing nfs exporting on fuse. The patch fixes it. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14fix SMP data race in pagetable setup vs walkingNick Piggin
There is a possible data race in the page table walking code. After the split ptlock patches, it actually seems to have been introduced to the core code, but even before that I think it would have impacted some architectures (powerpc and sparc64, at least, walk the page tables without taking locks eg. see find_linux_pte()). The race is as follows: The pte page is allocated, zeroed, and its struct page gets its spinlock initialized. The mm-wide ptl is then taken, and then the pte page is inserted into the pagetables. At this point, the spinlock is not guaranteed to have ordered the previous stores to initialize the pte page with the subsequent store to put it in the page tables. So another Linux page table walker might be walking down (without any locks, because we have split-leaf-ptls), and find that new pte we've inserted. It might try to take the spinlock before the store from the other CPU initializes it. And subsequently it might read a pte_t out before stores from the other CPU have cleared the memory. There are also similar races in higher levels of the page tables. They obviously don't involve the spinlock, but could see uninitialized memory. Arch code and hardware pagetable walkers that walk the pagetables without locks could see similar uninitialized memory problems, regardless of whether split ptes are enabled or not. I prefer to put the barriers in core code, because that's where the higher level logic happens, but the page table accessors are per-arch, and open-coding them everywhere I don't think is an option. I'll put the read-side barriers in alpha arch code for now (other architectures perform data-dependent loads in order). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13mm/pdflush.c: merge the same code in two pathDenis Cheng
Signed-off-by: Denis Cheng <crquan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13make vmstat cpu-unplug safeKOSAKI Motohiro
When accessing cpu_online_map, we should prevent dynamic changing of cpu_online_map by get_online_cpus(). Unfortunately, all_vm_events() doesn't do that. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Christoph Lameter <clameter@sgi.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>