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Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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[Ralf: Remove a forgotten -Werror in Pb1200 Makefile.]
Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
To: Linux-MIPS <linux-mips@linux-mips.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Manuel Lauss <manuel.lauss@googlemail.com>
Patchwork: https://patchwork.linux-mips.org/patch/1319/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Replace deprecated DMA_32BIT_MASK with DMA_BIT_MASK. This is needed because
the new style platform makefiles will enable -Werror.
cc1: warnings being treated as errors
arch/mips/alchemy/devboards/db1200/platform.c:219: error: 'DMA_nnBIT_MASK' is deprecated
arch/mips/alchemy/devboards/db1200/platform.c:226: error: 'DMA_nnBIT_MASK' is deprecated
arch/mips/alchemy/devboards/db1200/platform.c:388: error: 'DMA_nnBIT_MASK' is deprecated
arch/mips/alchemy/devboards/db1200/platform.c:393: error: 'DMA_nnBIT_MASK' is deprecated
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
To: linux-mips@linux-mips.org
Acked-by: Manuel Lauss <manuel.lauss@googlemail.com>
Patchwork: https://patchwork.linux-mips.org/patch/1427/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Preparatory step for moving Alchemy over to new MIPS Platform
build system support.
Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
To: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/1318/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
To: linux-mips <linux-mips@linux-mips.org>
Cc: Alexander Clouter <alex@digriz.org.uk>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>,
Patchwork: https://patchwork.linux-mips.org/patch/1313/
Patchwork: https://patchwork.linux-mips.org/patch/1326/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Move platform specific definitions to the platfrom directories.
Each platform shall do the following:
1) include an entry in arch/mips/Kbuild.platforms
2) add relevant definitions to arch/mips/<platform>/Platform
This commits changes ar7 to the new scheme as an example.
Introducing a platform speecific Platfrom file has following advantages:
1) decentralization of platfrom definitions
2) simplification af arch/mips/Makefile
3) force all platfrom to build with -Werror (done in arch/mips/Kbuild)
[Ralf: Remove forgotten -Werror from AR7 Makefile]
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
To: linux-mips <linux-mips@linux-mips.org>
To: Wu Zhangjin <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/1302/
Patchwork: http://patchwork.linux-mips.org/patch/1308/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Adding subdirs-ccflags-y := -Werror to arch/mips/Kbuild
let us in one go cover all files with -Werror.
In addition this allows us to remove the
individual -Werror definition in various Makefile.
Adding the definition to Kbuild as a recursive
option help us not to forget to do so.
With this change we now compile arch/mips/kernel/cpufreq with -Werror
One drawback:
When specifying a subdirectory covered by the Kbuild file like this:
make arch/mips/kernel/
then kbuild fails to pick up the -Werror definition.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
To: linux-mips <linux-mips@linux-mips.org>
To: Wu Zhangjin <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/1301/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
To: linux-mips <linux-mips@linux-mips.org>
To: Wu Zhangjin <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/1300/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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arch/mips/sgi-ip27/ip27-klconfig.c:51: ERROR: "foo * bar" should be "foo *bar"
arch/mips/sgi-ip27/ip27-klconfig.c:63: ERROR: "foo * bar" should be "foo *bar"
arch/mips/sgi-ip27/ip27-klconfig.c:81: ERROR: "foo * bar" should be "foo *bar"
arch/mips/sgi-ip27/ip27-klconfig.c:100: ERROR: "foo * bar" should be "foo *bar"
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1278/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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arch/mips/pci/ops-titan-ht.c:36: ERROR: "foo * bar" should be "foo *bar"
arch/mips/pci/ops-titan-ht.c:68: ERROR: "foo * bar" should be "foo *bar"
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1277/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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arch/mips/math-emu/sp_tlong.c:75: ERROR: else should follow close brace '}'
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1276/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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arch/mips/math-emu/sp_tint.c:76: ERROR: else should follow close brace '}'
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1275/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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arch/mips/math-emu/sp_modf.c:32: ERROR: "foo * bar" should be "foo *bar"
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1273/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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arch/mips/math-emu/dp_tlong.c:75: ERROR: else should follow close brace '}'
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1272/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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arch/mips/math-emu/dp_tint.c:73: ERROR: else should follow close brace '}'
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1271/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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arch/mips/math-emu/dp_modf.c:32: ERROR: "foo * bar" should be "foo *bar"
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1269/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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arch/mips/dec/promcon.c:37: ERROR: that open brace { should be on the previous line
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1270/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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arch/mips/pmc-sierra/yosemite/ht-irq.c:38: ERROR: code indent should use tabs where possible
arch/mips/pmc-sierra/yosemite/ht-irq.c:39: ERROR: code indent should use tabs where possible
arch/mips/pmc-sierra/yosemite/ht-irq.c:40: ERROR: code indent should use tabs where possible
arch/mips/pmc-sierra/yosemite/ht-irq.c:43: ERROR: code indent should use tabs where possible
arch/mips/pmc-sierra/yosemite/ht-irq.c:44: ERROR: code indent should use tabs where possible
arch/mips/pmc-sierra/yosemite/ht-irq.c:45: ERROR: code indent should use tabs where possible
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1268/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Correct ASIC device register names and addresses for USB devices.
Signed-off-by: David VomLehn <dvomlehn@cisco.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1258/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Replace phys_to_dma()/dma_to_phys() looping algorithm with an O(1) algorithm
The approach taken is inspired by the sparse memory implementation: take a
certain number of high-order bits off the address them, use this as an
index into a table containing an offset to the desired address and add
it to the original value. There is a table for mapping physical addresses
to DMA addresses and another one for the reverse mapping. The table sizes
depend on how fine-grained the mappings need to be; Coarser granularity
less to smaller tables. On a processor with 32-bit physical and DMA
addresses, with 4 MIB granularity, memory usage is two 2048-byte arrays.
Each 32-byte cache line thus covers 64 MiB of address space.
Also, renames phys_to_bus() to phys_to_dma() and bus_to_phys() to
dma_to_phys() to align with kernel usage.
[Ralf: Fixed silly build breakage due to stackoverflow warning caused by
huge array on stack.]
Signed-off-by: David VomLehn <dvomlehn@cisco.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1257/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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CC arch/mips/alchemy/mtx-1/board_setup.o
{standard input}: Assembler messages:
{standard input}:263: Error: opcode not supported on this processor: mips1 (mips1) `sync'
{standard input}:274: Error: opcode not supported on this processor: mips1 (mips1) `sync'
{standard input}:296: Error: opcode not supported on this processor: mips1 (mips1) `sync'
[...]
Any .set mipsX statement other than .set mips0 at the end of inline
assembler is a big fat bug.
Introduced by 9482eabeca315c0276ffb50026b7482481b7097b (linux-mips.org) rsp.
32fd6901a6d8d19f94e4de6be4e4b552ab078620 (kernel.org).
While at it, fix the same issue in
arch/mips/alchemy/devboards/pb1000/board_setup.c
arch/mips/alchemy/xxs1500/board_setup.c
as well.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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B43_pci_bridge is needed to use the b43 driver with brcm47xx. Activate it
by default if PCI is available.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1510/
Acked-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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The previous patch 4a86f2d27733f610e642649aca3e82e86fca9e22 (lmo) rsp.
84a6fcb368a080620d12fc4d79e07902dbee7335 (kernel.org) was wrong.
The BCM47xx architecture maps the ram into a 128MB address space. It
will be spaced there as often as goes into the 128MB. Detection tries to
find the position where the same memory is found. When reading beyond
128MB the processor will throw an exception. If 128MB RAM is installed,
it will not find a memory alias because it tries to read beyond the 128MB
border. Now it just assumes 128MB installed ram if it can not find an
alias.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1508/
Acked-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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When building with a gcc-4.4.x toolchain that is configured to produce
32-bits executables by default, we will produce __lshrti3 in sched_clock()
which is never resolved so the kernel fails to link. Unconditionally use
the inline assembly version as suggested by David Daney, which works around
the issue.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1514/
Acked-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1515/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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The 'mult' element of struct clock_event_device must never be wider
than 32-bits. If it were, it would get truncated when used by
clockevent_delta2ns() when this calls do_div().
We can meet this requirement by using clockevent_set_clock() to set
the MULT and SHIFT values.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1253/
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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The include is unecessary and will when building the IP35 result in
recursive header inclusion spaghetti.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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With SLAB, it works without ARCH_KMALLOC_MINALIGN, but with SLOB/SLUB,
ARCH_KMALLOC_MINALIGN is required to ensure alignment of kmalloced
buffer.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1248/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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request_region should be used with release_region, not request_mem_region.
Geert Uytterhoeven pointed out that in the case of drivers/video/gbefb.c,
the problem is actually the other way around; request_mem_region should be
used instead of request_region.
The semantic patch that finds/fixes this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@r1@
expression start;
@@
request_region(start,...)
@b1@
expression r1.start;
@@
request_mem_region(start,...)
@depends on !b1@
expression r1.start;
expression E;
@@
- release_mem_region
+ release_region
(start,E)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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nfs_commit_inode() needs to be defined irrespectively of whether or not
we are supporting NFSv3 and NFSv4.
Allow the compiler to optimise away code in the NFSv2-only case by
converting it into an inlined stub function.
Reported-and-tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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* master.kernel.org:/home/rmk/linux-2.6-arm:
cyber2000fb: fix console in truecolor modes
cyber2000fb: fix machine hang on module load
SA1111: Eliminate use after free
ARM: Fix Versatile/Realview/VExpress MMC card detection sense
ARM: 6279/1: highmem: fix SMP preemption bug in kmap_high_l1_vipt
ARM: Add barriers to io{read,write}{8,16,32} accessors as well
ARM: 6273/1: Add barriers to the I/O accessors if ARM_DMA_MEM_BUFFERABLE
ARM: 6272/1: Convert L2x0 to use the IO relaxed operations
ARM: 6271/1: Introduce *_relaxed() I/O accessors
ARM: 6275/1: ux500: don't use writeb() in uncompress.h
ARM: 6270/1: clean files in arch/arm/boot/compressed/
ARM: Fix csum_partial_copy_from_user()
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* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
NFS: Ensure that writepage respects the nonblock flag
NFS: kswapd must not block in nfs_release_page
nfs: include space for the NUL in root path
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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/edid: Fix the HDTV hack sync adjustment
drm/radeon/kms: fix radeon mid power profile reporting
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Debian's ia64 autobuilders have been seeing kernel freeze or reboot
when running the gdb testsuite (Debian bug 588574): dannf bisected to
2.6.32 62eede62dafb4a6633eae7ffbeb34c60dba5e7b1 "mm: ZERO_PAGE without
PTE_SPECIAL"; and reproduced it with gdb's gcore on a simple target.
I'd missed updating the gate_vma handling in __get_user_pages(): that
happens to use vm_normal_page() (nowadays failing on the zero page),
yet reported success even when it failed to get a page - boom when
access_process_vm() tried to copy that to its intermediate buffer.
Fix this, resisting cleanups: in particular, leave it for now reporting
success when not asked to get any pages - very probably safe to change,
but let's not risk it without testing exposure.
Why did ia64 crash with 16kB pages, but succeed with 64kB pages?
Because setup_gate() pads each 64kB of its gate area with zero pages.
Reported-by: Andreas Barth <aba@not.so.argh.org>
Bisected-by: dann frazier <dannf@debian.org>
Signed-off-by: Hugh Dickins <hughd@google.com>
Tested-by: dann frazier <dannf@dannf.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Remove the __exit mark from cifs_exit_dns_resolver() as it's called by the
module init routine in case of error, and so may have been discarded during
linkage.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Return value was not set to 0 in setcolreg() with truecolor modes. This causes
fb_set_cmap() to abort after first color, resulting in blank palette - and
blank console in 24bpp and 32bpp modes.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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I was testing two CyberPro 2000 based PCI cards on x86 and the machine always
hanged completely when the cyber2000fb module was loaded. It seems that the
card hangs when some registers are accessed too quickly after writing RAMDAC
control register. With this patch, both card work.
Add delay after RAMDAC control register write to prevent hangs on module load.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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__sa1111_remove always frees its argument, so the subsequent reference to
sachip->saved_state represents a use after free. __sa1111_remove does not
appear to use the saved_state field, so the patch simply frees it first.
A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
expression E,E2;
@@
__sa1111_remove(E)
...
(
E = E2
|
* E
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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The MMC card detection sense has become really confused with negations
at various levels, leading to some platforms not detecting inserted
cards. Fix this by converting everything to positive logic throughout,
thereby getting rid of these negations.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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smp_processor_id() must not be called from a preemptible context (this
is checked by CONFIG_DEBUG_PREEMPT). kmap_high_l1_vipt() was doing so.
This lead to a problem where the wrong per_cpu kmap_high_l1_vipt_depth
could be incremented, causing a BUG_ON(*depth <= 0); in
kunmap_high_l1_vipt().
The solution is to move the call to smp_processor_id() after the call
to preempt_disable().
Originally by: Andrew Howe <ahowe@nvidia.com>
Signed-off-by: Gary King <gking@nvidia.com>
Acked-by: Nicolas Pitre <nico.as.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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See https://bugzilla.kernel.org/show_bug.cgi?id=16056
If other processes are blocked waiting for kswapd to free up some memory so
that they can make progress, then we cannot allow kswapd to block on those
processes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
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In root_nfs_name() it does the following:
if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) {
printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n");
return -1;
}
sprintf(nfs_export_path, buf, cp);
In the original code if (strlen(buf) + strlen(cp) == NFS_MAXPATHLEN)
then the sprintf() would lead to an overflow. Generally the rest of the
code assumes that the path can have NFS_MAXPATHLEN (1024) characters and
a NUL terminator so the fix is to add space to the nfs_export_path[]
buffer.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
[S390] etr: fix clock synchronization race
[S390] Fix IRQ tracing in case of PER
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* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
watchdog: update MAINTAINERS entry
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git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
* 'fix/hda' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
ALSA: hda - Add a PC-beep workaround for ASUS P5-V
ALSA: hda - Assume PC-beep as default for Realtek
ALSA: hda - Don't register beep input device when no beep is available
ALSA: hda - Fix pin-detection of Nvidia HDMI
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Fix __task_cred()'s lockdep check by removing the following validation
condition:
lockdep_tasklist_lock_is_held()
as commit_creds() does not take the tasklist_lock, and nor do most of the
functions that call it, so this check is pointless and it can prevent
detection of the RCU lock not being held if the tasklist_lock is held.
Instead, add the following validation condition:
task->exit_state >= 0
to permit the access if the target task is dead and therefore unable to change
its own credentials.
Fix __task_cred()'s comment to:
(1) discard the bit that says that the caller must prevent the target task
from being deleted. That shouldn't need saying.
(2) Add a comment indicating the result of __task_cred() should not be passed
directly to get_cred(), but rather than get_task_cred() should be used
instead.
Also put a note into the documentation to enforce this point there too.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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It's possible for get_task_cred() as it currently stands to 'corrupt' a set of
credentials by incrementing their usage count after their replacement by the
task being accessed.
What happens is that get_task_cred() can race with commit_creds():
TASK_1 TASK_2 RCU_CLEANER
-->get_task_cred(TASK_2)
rcu_read_lock()
__cred = __task_cred(TASK_2)
-->commit_creds()
old_cred = TASK_2->real_cred
TASK_2->real_cred = ...
put_cred(old_cred)
call_rcu(old_cred)
[__cred->usage == 0]
get_cred(__cred)
[__cred->usage == 1]
rcu_read_unlock()
-->put_cred_rcu()
[__cred->usage == 1]
panic()
However, since a tasks credentials are generally not changed very often, we can
reasonably make use of a loop involving reading the creds pointer and using
atomic_inc_not_zero() to attempt to increment it if it hasn't already hit zero.
If successful, we can safely return the credentials in the knowledge that, even
if the task we're accessing has released them, they haven't gone to the RCU
cleanup code.
We then change task_state() in procfs to use get_task_cred() rather than
calling get_cred() on the result of __task_cred(), as that suffers from the
same problem.
Without this change, a BUG_ON in __put_cred() or in put_cred_rcu() can be
tripped when it is noticed that the usage count is not zero as it ought to be,
for example:
kernel BUG at kernel/cred.c:168!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/kernel/mm/ksm/run
CPU 0
Pid: 2436, comm: master Not tainted 2.6.33.3-85.fc13.x86_64 #1 0HR330/OptiPlex
745
RIP: 0010:[<ffffffff81069881>] [<ffffffff81069881>] __put_cred+0xc/0x45
RSP: 0018:ffff88019e7e9eb8 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff880161514480 RCX: 00000000ffffffff
RDX: 00000000ffffffff RSI: ffff880140c690c0 RDI: ffff880140c690c0
RBP: ffff88019e7e9eb8 R08: 00000000000000d0 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000040 R12: ffff880140c690c0
R13: ffff88019e77aea0 R14: 00007fff336b0a5c R15: 0000000000000001
FS: 00007f12f50d97c0(0000) GS:ffff880007400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f461bc000 CR3: 00000001b26ce000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process master (pid: 2436, threadinfo ffff88019e7e8000, task ffff88019e77aea0)
Stack:
ffff88019e7e9ec8 ffffffff810698cd ffff88019e7e9ef8 ffffffff81069b45
<0> ffff880161514180 ffff880161514480 ffff880161514180 0000000000000000
<0> ffff88019e7e9f28 ffffffff8106aace 0000000000000001 0000000000000246
Call Trace:
[<ffffffff810698cd>] put_cred+0x13/0x15
[<ffffffff81069b45>] commit_creds+0x16b/0x175
[<ffffffff8106aace>] set_current_groups+0x47/0x4e
[<ffffffff8106ac89>] sys_setgroups+0xf6/0x105
[<ffffffff81009b02>] system_call_fastpath+0x16/0x1b
Code: 48 8d 71 ff e8 7e 4e 15 00 85 c0 78 0b 8b 75 ec 48 89 df e8 ef 4a 15 00
48 83 c4 18 5b c9 c3 55 8b 07 8b 07 48 89 e5 85 c0 74 04 <0f> 0b eb fe 65 48 8b
04 25 00 cc 00 00 48 3b b8 58 04 00 00 75
RIP [<ffffffff81069881>] __put_cred+0xc/0x45
RSP <ffff88019e7e9eb8>
---[ end trace df391256a100ebdd ]---
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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