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2009-03-14x86: allow extend_brk users to reserve brk spaceJeremy Fitzhardinge
Impact: new interface; remove hard-coded limit Add RESERVE_BRK(name, size) macro to reserve space in the brk area. This should be a conservative (ie, larger) estimate of how much space might possibly be required from the brk area. Any unused space will be freed, so there's no real downside on making the reservation too large (within limits). The name should be unique within a given file, and somewhat descriptive. The C definition of RESERVE_BRK() ends up being more complex than one would expect to work around a cluster of gcc infelicities: The first attempt was to simply try putting __section(.brk_reservation) on a variable. This doesn't work because it ends up making it a @progbits section, which gets actual space allocated in the vmlinux executable. The second attempt was to emit the space into a section using asm, but gcc doesn't allow arguments to be passed to file-level asm() statements, making it hard to pass in the size. The final attempt is to wrap the asm() in a function to allow it to have arguments, and put the function itself into the .discard section, which vmlinux*.lds drops entirely from the emitted vmlinux. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-14x86-32: compute initial mapping size more accuratelyYinghai Lu
Impact: simplification We only need to map the kernel in head_32.S, not the whole of lowmem. We use 512MB as a reasonable (but arbitrary) limit on the maximum size of the kernel image. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-14x86: use brk allocation for DMIJeremy Fitzhardinge
Impact: use new interface instead of previous ad hoc implementation Use extend_brk() to allocate memory for DMI rather than having an ad-hoc allocator. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-14x86-32: use brk segment for allocating initial kernel pagetableJeremy Fitzhardinge
Impact: use new interface instead of previous ad hoc implementation Rather than having special purpose init_pg_table_start/end variables to delimit the kernel pagetable built by head_32.S, just use the brk mechanism to extend the bss for the new pagetable. This patch removes init_pg_table_start/end and pg0, defines __brk_base (which is page-aligned and immediately follows _end), initializes the brk region to start there, and uses it for the 32-bit pagetable. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-14x86: move brk initialization out of #ifdef CONFIG_BLK_DEV_INITRDH. Peter Anvin
Impact: build fix The brk initialization functions were incorrectly located inside an #ifdef CONFIG_VLK_DEV_INITRD block, causing the obvious build failure in minimal configurations. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-03-14x86: add brk allocation for very, very early allocationsJeremy Fitzhardinge
Impact: new interface Add a brk()-like allocator which effectively extends the bss in order to allow very early code to do dynamic allocations. This is better than using statically allocated arrays for data in subsystems which may never get used. The space for brk allocations is in the bss ELF segment, so that the space is mapped properly by the code which maps the kernel, and so that bootloaders keep the space free rather than putting a ramdisk or something into it. The bss itself, delimited by __bss_stop, ends before the brk area (__brk_base to __brk_limit). The kernel text, data and bss is reserved up to __bss_stop. Any brk-allocated data is reserved separately just before the kernel pagetable is built, as that code allocates from unreserved spaces in the e820 map, potentially allocating from any unused brk memory. Ultimately any unused memory in the brk area is used in the general kernel memory pool. Initially the brk space is set to 1MB, which is probably much larger than any user needs (the largest current user is i386 head_32.S's code to build the pagetables to map the kernel, which can get fairly large with a big kernel image and no PSE support). So long as the system has sufficient memory for the bootloader to reserve the kernel+1MB brk, there are no bad effects resulting from an over-large brk. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-14x86: make section delimiter symbols part of their sectionJeremy Fitzhardinge
Impact: cleanup Move the symbols delimiting a section part of the section (section relative) rather than absolute. This avoids any unexpected gaps between the section-start symbol and the first data in the section, which could be caused by implicit alignment of the section data. It also makes the general form of vmlinux_64.lds.S consistent with vmlinux_32.lds.S. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-14Merge branch 'core/percpu' into x86/coreIngo Molnar
2009-03-13cpuacct: reduce one NULL check in fast-pathLi Zefan
Impact: micro-optimization In cpuacct_charge(), task_ca() will never return NULL, so change for(...) to do { } while(...) to save one NULL check. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Bharata B Rao <bharata@linux.vnet.ibm.com> LKML-Reference: <49B863F5.2060400@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12Merge branches 'x86/asm', 'x86/debug', 'x86/mm', 'x86/setup', 'x86/urgent' ↵Ingo Molnar
and 'linus' into x86/core
2009-03-11x86: mmiotrace: quieten spurious warning messageStuart Bennett
This message was being incorrectly emitted when using gdb, so compile it out by default for now; there will be a better fix in v2.6.30. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Stuart Bennett <stuart@freedesktop.org> Acked-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-11Merge branch 'drm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 * 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: drm: fix EDID parser problem with positive/negative hsync/vsync
2009-03-11Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: radeonfb/aty128fb: Disable broken early resume hook for PowerBooks hvc_console: Remove tty->low_latency on pseries backends powerpc: fix linkstation and storcenter compilation breakage powerpc/4xx: Enable SERIAL_OF support by default for Virtex platforms
2009-03-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel: drm/i915: fix 945 fence register writes for fence 8 and above. drm/i915: Protect active fences on i915 drm/i915: Check to see if we've pinned all available fences drm/i915: Check fence status on every pin. drm/i915: First recheck for an empty fence register. drm/i915: Fix bad \n in MTRR failure notice. drm/i915: Don't restore palettes through VGA registers. i915: add newline to i915_gem_object_pin failure msg drm: Return EINVAL on duplicate objects in execbuffer object list
2009-03-11Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: work around Fedora-11 x86-32 kernel failures on Intel Atom CPUs
2009-03-11Fix _fat_bmap() lockingOGAWA Hirofumi
On swapon() path, it has already i_mutex. So, this uses i_alloc_sem instead of it. Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Reported-by: Laurent GUERBY <laurent@guerby.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-11drm/i915: fix 945 fence register writes for fence 8 and above.Eric Anholt
The last 8 fence registers sit at a different offset, so when we went to set fence number 8 in the lower offset, we instead set PGETBL_CTL, and the GPU got all sorts of angry at us. fd.o bug #20567. Easily reproducible by running glxgears and killing it about 6 times. Signed-off-by: Eric Anholt <eric@anholt.net>
2009-03-11x86: remove zImage supportH. Peter Anvin
Impact: obsolete feature removal The zImage kernel format has been functionally unused for a very long time. It is just barely possible to build a modern kernel that still fits within the zImage size limit, but it is highly unlikely that anyone ever uses it. Furthermore, although it is still supported by most bootloaders, it has been at best poorly tested (or not tested at all); some bootloaders are even known to not support zImage at all and not having even noticed. Also remove some really obsolete constants that no longer have any meaning. LKML-Reference: <49B703D4.1000008@zytor.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-11drm/i915: Protect active fences on i915Chris Wilson
The i915 also uses the fence registers for GPU access to tiled buffers so we cannot reallocate one whilst it is on the active list. By performing a LRU scan of the fenced buffers we also avoid waiting the possibility of waiting on a pinned, or otherwise unusable, buffer. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Eric Anholt <eric@anholt.net>
2009-03-11x86: work around Fedora-11 x86-32 kernel failures on Intel Atom CPUsIngo Molnar
Impact: work around boot crash Work around Intel Atom erratum AAH41 (probabilistically) - it's triggering in the field. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Kyle McMartin <kyle@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-11x86: debug check for kmap_atomic_pfn and iomap_atomic_prot_pfn()Akinobu Mita
It may be useful for kmap_atomic_pfn() and iomap_atomic_prot_pfn() to check invalid kmap usage as well as kmap_atomic. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> LKML-Reference: <20090311143449.GB22244@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-11x86: unify kmap_atomic_pfn() and iomap_atomic_prot_pfn()Akinobu Mita
kmap_atomic_pfn() and iomap_atomic_prot_pfn() are almost same except pgprot. This patch removes the code duplication for these two functions. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> LKML-Reference: <20090311143317.GA22244@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-11proc: fix kflags to uflags copying in /proc/kpageflagsWu Fengguang
Fix kpf_copy_bit(src,dst) to be kpf_copy_bit(dst,src) to match the actual call patterns, e.g. kpf_copy_bit(kflags, KPF_LOCKED, PG_locked). This misplacement of src/dst only affected reporting of PG_writeback, PG_reclaim and PG_buddy. For others kflags==uflags so not affected. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-11x86: cpu architecture debug code, build fix, cleanupJaswinder Singh Rajput
move store_ldt outside the CONFIG_PARAVIRT section and also clean up the code a bit. Signed-off-by: Jaswinder Singh Rajput <jaswinder@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-11x86: shrink __ALIGN and __ALIGN_STR definitionsCyrill Gorcunov
Impact: cleanup 1) .p2align 4 and .align 16 are the same meaning (until a.out format for i386 is used which is not our case for CONFIG_X86_ALIGNMENT_16 anyway) 2) having 15 as max allowed bytes to be skipped does not make sense on modulo 16 Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> LKML-Reference: <20090309171951.GE9945@localhost> [ small cleanup, use __stringify(), etc. ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-11Merge branches 'x86/cleanups', 'x86/kexec', 'x86/mce2' and 'linus' into x86/coreIngo Molnar
2009-03-11Merge branch 'tj-percpu' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into core/percpu
2009-03-11Merge branch 'linus' into core/percpuIngo Molnar
Conflicts: arch/x86/include/asm/fixmap_64.h
2009-03-11x86: convert obsolete irq_desc_t typedef to struct irq_descThomas Gleixner
Impact: cleanup Convert the last remaining users. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-03-11percpu: fix spurious alignment WARN in legacy SMP percpu allocatorTejun Heo
Impact: remove spurious WARN on legacy SMP percpu allocator Commit f2a8205c4ef1af917d175c36a4097ae5587791c8 incorrectly added too tight WARN_ON_ONCE() on alignments for UP and legacy SMP percpu allocator. Commit e317603694bfd17b28a40de9d65e1a4ec12f816e fixed it for UP but legacy SMP allocator was forgotten. Fix it. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Sachin P. Sant <sachinp@in.ibm.com>
2009-03-10x86, mce: use round_jiffies() instead round_jiffies_relative()KOSAKI Motohiro
Impact: saving power _very_ little round_jiffies() round up absolute jiffies to full second. round_jiffies_relative() round up relative jiffies to full second. The "t->expires" is absolute jiffies. Then, round_jiffies() should be used instead round_jiffies_relative(). Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-10drm/i915: Check to see if we've pinned all available fencesChris Wilson
We need to check and report if there are no available fences - or else we spin endlessly waiting for a buffer to magically unpin itself. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Eric Anholt <eric@anholt.net>
2009-03-10drm/i915: Check fence status on every pin.Chris Wilson
As we may steal the fence register of an unpinned buffer for another, every time we repin the buffer we need to recheck whether it needs to be allocated a fence. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Eric Anholt <eric@anholt.net>
2009-03-10drm/i915: First recheck for an empty fence register.Chris Wilson
If we wait upon a request and successfully unbind a buffer occupying a fence register, then that slot will be freed and cause a NULL derefrence upon rescanning. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Eric Anholt <eric@anholt.net>
2009-03-11drm: fix EDID parser problem with positive/negative hsync/vsyncPantelis Koukousoulas
Comparing the layouts of struct detail_pixel_timing with x.org's struct detailed_timings and how those are handled, it appears that the hsync_positive and vsync_positive fields are backwards. This patch fixes https://bugs.freedesktop.org/show_bug.cgi?id=20019 for me. It was tested on 2 monitors, LG FLATRON L225WS 22" and a YAKUMO 17" for which more details are unknown. Signed-off-by: Pantelis Koukousoulas <pktoss@gmail.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
2009-03-10x86, kexec: x86_64: add kexec jump support for x86_64Huang Ying
Impact: New major feature This patch add kexec jump support for x86_64. More information about kexec jump can be found in corresponding x86_32 support patch. Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-10x86, kexec: x86_64: add identity map for pages at image->startHuang Ying
Impact: Fix corner case that cannot yet occur image->start may be outside of 0 ~ max_pfn, for example when jumping back to original kernel from kexeced kenrel. This patch add identity map for pages at image->start. Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-10x86, kexec: fix kexec x86 coding styleHuang Ying
Impact: Cleanup Fix some coding style issue for kexec x86. Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-11radeonfb/aty128fb: Disable broken early resume hook for PowerBooksBenjamin Herrenschmidt
radeonfb and aty128fb have a special hook called by the PowerMac platform code very very early on resume from sleep to bring the screen back. This is useful for debugging wakup problems, but unfortunately, this also became a source of problems of its own. The hook is called extremely early, with interrupts still off, and the code path involved with that code nowadays rely on things like taking mutexes, GFP_KERNEL allocations, etc... In addition, the driver now relies on the PCI core to restore the standard config space before calling resume which doesn't happen with this early code path. I'm keeping the code in but commented out along with a fixup call to pci_restore_state(). The reason is that I still want to make it easy to re-enable temporarily to track wake up problems, and it's possible that I can revive it at some stage if we make sleeping things save to call in early resume using a system state. In the meantime, this should fix several reported regressions. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-03-11hvc_console: Remove tty->low_latency on pseries backendsBenjamin Herrenschmidt
The hvcs and hvsi backends both set tty->low_latency to one, along with more or less scary comments regarding bugs or races that would happen if not doing so. However, they also both call tty_flip_buffer_push() in conexts where it's illegal to do so since some recent tty changes (or at least it may have been illegal always but it nows blows) when low_latency is set (ie, hard interrupt or with spinlock held and irqs disabled). This removes the setting for now to get them back to working condition, we'll have to address the races described in the comments separately if they are still an issue (some of this might have been fixed already). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-03-11Merge commit 'gcl/merge' into mergeBenjamin Herrenschmidt
2009-03-10i810: fix kernel crash fix when struct fb_var_screeninfo is suppliedSamuel CUELLA
Prevent the kernel from being crashed by a divide-by-zero operation when supplied an incorrectly filled 'struct fb_var_screeninfo' from userland. Previously i810_main.c:1005 (i810_check_params) was using the global 'yres' symbol previously defined at i810_main.c:145 as a module parameter value holder (i810_main.c:2174). If i810fb is compiled-in or if this param doesn't get a default value, this direct usage leads to a divide-by-zero at i810_main.c:1005 (i810_check_params). The patch simply replace the 'yres' global, perhaps undefined symbol usage by a given parameter structure lookup. This problem occurs with directfb, mplayer -vo fbdev, SDL library. It was also reported ( but non solved ) at: http://mail.directfb.org/pipermail/directfb-dev/2008-March/004050.html Signed-off-by: Samuel CUELLA <samuel.cuella@supinfo.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Krzysztof Helt <krzysztof.h1@poczta.fm> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-10m68knommu: m528x build fixSteven King
There isn't any mcfqspi.h in the tree, and without it everything inside the #ifdef CONFIG_SPI is uncompilable. Signed-off-by: Steven King <sfking@fdwdc.com> Acked-by: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-10m68knommu: m5206e build fixSteven King
Signed-off-by: Steven King <sfking@fdwdc.com> Acked-by: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-10rcu: documentation 1Q09 updatePaul E. McKenney
Update the RCU documentation to call out the need for callers of primitives like call_rcu() and synchronize_rcu() to prevent subsequent RCU readers from hazard. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-10kernel/user.c: fix a memory leak when freeing up non-init usernamespaces usersDhaval Giani
We were returning early in the sysfs directory cleanup function if the user belonged to a non init usernamespace. Due to this a lot of the cleanup was not done and we were left with a leak. Fix the leak. Reported-by: Serge Hallyn <serue@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Tested-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-10mtd: physmap: fix NULL pointer dereference in error pathAtsushi Nemoto
commit e480814f138cd5d78a8efe397756ba6b6518fdb6 ("[MTD] [MAPS] physmap: fix wrong free and del_mtd_{partition,device}") introduces a NULL pointer dereference in physmap_flash_remove when called from the error path in physmap_flash_probe (if map_probe failed). Call del_mtd_{partition,device} only if info->cmtd was not NULL. Reported-by: pHilipp Zabel <philipp.zabel@gmail.com> Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Cc: David Woodhouse <dwmw2@infradead.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-10intel-agp: fix a panic with 1M of shared memory, no GTT entriesLubomir Rintel
When GTT size is equal to amount of video memory, the amount of GTT entries is computed lower than zero, which is invalid and leads to off-by-one error in intel_i915_configure() Originally posted here: http://bugzilla.kernel.org/show_bug.cgi?id=12539 http://bugzilla.redhat.com/show_bug.cgi?id=445592 Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Cc: Lubomir Rintel <lkundrak@v3.sk> Cc: Dave Airlie <airlied@linux.ie> Reviewed-by: Eric Anholt <eric@anholt.net> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-10mtd_dataflash: fix probing of AT45DB321C chips.Will Newton
Commit 771999b65f79264acde4b855e5d35696eca5e80c ("[MTD] DataFlash: bugfix, binary page sizes now handled") broke support for probing AT45DB321C flash chips. These chips do not support the "page size" status bit, so if we match the JEDEC id return early. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Will Newton <will.newton@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-10idr: make idr_remove_all() do removal -before- free_layer()Paul E. McKenney
Fix a problem in the IDR system, where an idr_remove_all() hands a data element to call_rcu() (via free_layer()) before making that data element inaccessible to new readers. This is very bad, and results in readers still having a reference to this data element at the end of the grace period. Tests on large machines that concurrently map and unmap user-space memory within the same multithreaded process result in crashes within about five minutes. Applying this patch increases the kernel's longevity to the three-to-eight-hour range. There appear to be other similar problems in idr_get_empty_slot() and sub_remove(), but I fixed the easy one in idr_remove_all() first. It is therefore no surprise that failures still occur. Located-by: Milton Miller II <miltonm@austin.ibm.com> Tested-by: Milton Miller II <miltonm@austin.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>