The kdb_current legally be equal to NULL in the early boot of the x86
arch. The problem pcan be observed by booting with the kernel arguments:
earlyprintk=vga ekgdboc=kbd kgdbwait
The kdb shell will oops on entry and recursively fault because it
cannot get past the final stage of shell initialization.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
DBG_MAX_REG_NUM incorrectly had the number of indices in the GDB regs
array rather than the number of registers, leading to an oops when the
"rd" command is used in KDB.
Cc: stable@kernel.org
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Rusty pointed out that the per_cpu command uses up lots of space on
the stack and the cpu supress mask is probably not needed.
This patch removes the need for the supress mask as well as fixing up
the following problems with the kdb per_cpu command:
* The per_cpu command should allow an address as an argument
* When you have more data than can be displayed on one screen allow
the user to break out of the print loop.
Reported-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
usbfs_get_inode() is something completely different...
Bogosity introduced by commit 85fe4025c6 ("fs: do not assign default
i_ino in new_inode").
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (476 commits)
vmwgfx: Implement a proper GMR eviction mechanism
drm/radeon/kms: fix r6xx/7xx 1D tiling CS checker v2
drm/radeon/kms: properly compute group_size on 6xx/7xx
drm/radeon/kms: fix 2D tile height alignment in the r600 CS checker
drm/radeon/kms/evergreen: set the clear state to the blit state
drm/radeon/kms: don't poll dac load detect.
gpu: Add Intel GMA500(Poulsbo) Stub Driver
drm/radeon/kms: MC vram map needs to be >= pci aperture size
drm/radeon/kms: implement display watermark support for evergreen
drm/radeon/kms/evergreen: add some additional safe regs v2
drm/radeon/r600: fix tiling issues in CS checker.
drm/i915: Move gpu_write_list to per-ring
drm/i915: Invalidate the to-ring, flush the old-ring when updating domains
drm/i915/ringbuffer: Write the value passed in to the tail register
agp/intel: Restore valid PTE bit for Sandybridge after bdd3072
drm/i915: Fix flushing regression from 9af90d19f
drm/i915/sdvo: Remove unused encoding member
i915: enable AVI infoframe for intel_hdmi.c [v4]
drm/i915: Fix current fb blocking for page flip
drm/i915: IS_IRONLAKE is synonymous with gen == 5
...
Fix up conflicts in
- drivers/gpu/drm/i915/{i915_gem.c, i915/intel_overlay.c}: due to the
new simplified stack-based kmap_atomic() interface
- drivers/gpu/drm/vmwgfx/vmwgfx_drv.c: added .llseek entry due to BKL
removal cleanups.
* 'upstream/xenfs' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
xen/privcmd: make privcmd visible in domU
xen/privcmd: move remap_domain_mfn_range() to core xen code and export.
privcmd: MMAPBATCH: Fix error handling/reporting
xenbus: export xen_store_interface for xenfs
xen/privcmd: make sure vma is ours before doing anything to it
xen/privcmd: print SIGBUS faults
xen/xenfs: set_page_dirty is supposed to return true if it dirties
xen/privcmd: create address space to allow writable mmaps
xen: add privcmd driver
xen: add variable hypercall caller
xen: add xen_set_domain_pte()
xen: add /proc/xen/xsd_{kva,port} to xenfs
* 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen: (29 commits)
xen: include xen/xen.h for definition of xen_initial_domain()
xen: use host E820 map for dom0
xen: correctly rebuild mfn list list after migration.
xen: improvements to VIRQ_DEBUG output
xen: set up IRQ before binding virq to evtchn
xen: ensure that all event channels start off bound to VCPU 0
xen/hvc: only notify if we actually sent something
xen: don't add extra_pages for RAM after mem_end
xen: add support for PAT
xen: make sure xen_max_p2m_pfn is up to date
xen: limit extra memory to a certain ratio of base
xen: add extra pages for E820 RAM regions, even if beyond mem_end
xen: make sure xen_extra_mem_start is beyond all non-RAM e820
xen: implement "extra" memory to reserve space for pages not present at boot
xen: Use host-provided E820 map
xen: don't map missing memory
xen: defer building p2m mfn structures until kernel is mapped
xen: add return value to set_phys_to_machine()
xen: convert p2m to a 3 level tree
xen: make install_p2mtop_page() static
...
Fix up trivial conflict in arch/x86/xen/mmu.c, and fix the use of
'reserve_early()' - in the new memblock world order it is now
'memblock_x86_reserve_range()' instead. Pointed out by Jeremy.
Use Ben's new range manager hooks to implement a manager for
GMRs that manages ids rather than ranges.
This means we can use the standard TTM code for binding, unbinding and
eviction.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits)
split invalidate_inodes()
fs: skip I_FREEING inodes in writeback_sb_inodes
fs: fold invalidate_list into invalidate_inodes
fs: do not drop inode_lock in dispose_list
fs: inode split IO and LRU lists
fs: switch bdev inode bdi's correctly
fs: fix buffer invalidation in invalidate_list
fsnotify: use dget_parent
smbfs: use dget_parent
exportfs: use dget_parent
fs: use RCU read side protection in d_validate
fs: clean up dentry lru modification
fs: split __shrink_dcache_sb
fs: improve DCACHE_REFERENCED usage
fs: use percpu counter for nr_dentry and nr_dentry_unused
fs: simplify __d_free
fs: take dcache_lock inside __d_path
fs: do not assign default i_ino in new_inode
fs: introduce a per-cpu last_ino allocator
new helper: ihold()
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband: (63 commits)
IB/qib: clean up properly if pci_set_consistent_dma_mask() fails
IB/qib: Allow driver to load if PCIe AER fails
IB/qib: Fix uninitialized pointer if CONFIG_PCI_MSI not set
IB/qib: Fix extra log level in qib_early_err()
RDMA/cxgb4: Remove unnecessary KERN_<level> use
RDMA/cxgb3: Remove unnecessary KERN_<level> use
IB/core: Add link layer type information to sysfs
IB/mlx4: Add VLAN support for IBoE
IB/core: Add VLAN support for IBoE
IB/mlx4: Add support for IBoE
mlx4_en: Change multicast promiscuous mode to support IBoE
mlx4_core: Update data structures and constants for IBoE
mlx4_core: Allow protocol drivers to find corresponding interfaces
IB/uverbs: Return link layer type to userspace for query port operation
IB/srp: Sync buffer before posting send
IB/srp: Use list_first_entry()
IB/srp: Reduce number of BUSY conditions
IB/srp: Eliminate two forward declarations
IB/mlx4: Signal node desc changes to SM by using FW to generate trap 144
IB: Replace EXTRA_CFLAGS with ccflags-y
...
broken by:
drm/radeon/r600: fix tiling issues in CS checker.
v2: only apply it to 1D tiling case.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Add more wait, wake, and completion interfaces to the device-drivers
docbook.
Fix kernel-doc notation in the added files.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
PM / Runtime: fix recursive locking warning of lockdep from rpm_resume()
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (53 commits)
ACPI: install ACPI table handler before any dynamic tables being loaded
ACPI / PM: Blacklist another machine that needs acpi_sleep=nonvs
ACPI: Page based coalescing of I/O remappings optimization
ACPI: Convert simple locking to RCU based locking
ACPI: Pre-map 'system event' related register blocks
ACPI: Add interfaces for ioremapping/iounmapping ACPI registers
ACPI: Maintain a list of ACPI memory mapped I/O remappings
ACPI: Fix ioremap size for MMIO reads and writes
ACPI / Battery: Return -ENODEV for unknown values in get_property()
ACPI / PM: Fix reference counting of power resources
Subject: [PATCH] ACPICA: Fix Scope() op in module level code
ACPI battery: support percentage battery remaining capacity
ACPI: Make Embedded Controller command timeout delay configurable
ACPI dock: move some functions to .init.text
ACPI: thermal: remove unused limit code
ACPI: static sleep_states[] and acpi_gts_bfs_check
ACPI: remove dead code
ACPI: delete dedicated MAINTAINERS entries for ACPI EC and BATTERY drivers
ACPI: Only processor needs CPU_IDLE
ACPICA: Update version to 20101013
...
* 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6:
intel_idle: do not use the LAPIC timer for ATOM C2
intel_idle: add initial Sandy Bridge support
acpi_idle: delete bogus data from cpuidle_state.power_usage
intel_idle: delete bogus data from cpuidle_state.power_usage
intel_idle: simplify test for leave_mm()
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
arch/tile: convert a BUG_ON to BUILD_BUG_ON
arch/tile: make ptrace() work properly for TILE-Gx COMPAT mode
arch/tile: support new info op generated by compiler
arch/tile: minor whitespace/naming changes for string support files
arch/tile: enable single-step support for TILE-Gx
arch/tile: parameterize system PLs to support KVM port
arch/tile: add Tilera's <arch/sim.h> header as an open-source header
arch/tile: Bomb C99 comments to C89 comments in tile's <arch/sim_def.h>
arch/tile: prevent corrupt top frame from causing backtracer runaway
arch/tile: various top-level Makefile cleanups
arch/tile: change lower bound on syscall error return to -4095
arch/tile: properly export __mb_incoherent for modules
arch/tile: provide a definition of MAP_STACK
kmemleak: add TILE to the list of supported architectures.
char: hvc: check for error case
arch/tile: Add a warning if we try to allocate too much vmalloc memory.
arch/tile: update some comments to clarify register usage.
arch/tile: use better "punctuation" for VMSPLIT_3_5G and friends
arch/tile: Use <asm-generic/syscalls.h>
tile: replace some BUG_ON checks with BUILD_BUG_ON checks
* akpm-incoming-1: (176 commits)
scripts/checkpatch.pl: add check for declaration of pci_device_id
scripts/checkpatch.pl: add warnings for static char that could be static const char
checkpatch: version 0.31
checkpatch: statement/block context analyser should look at sanitised lines
checkpatch: handle EXPORT_SYMBOL for DEVICE_ATTR and similar
checkpatch: clean up structure definition macro handline
checkpatch: update copyright dates
checkpatch: Add additional attribute #defines
checkpatch: check for incorrect permissions
checkpatch: ensure kconfig help checks only apply when we are adding help
checkpatch: simplify and consolidate "missing space after" checks
checkpatch: add check for space after struct, union, and enum
checkpatch: returning errno typically should be negative
checkpatch: handle casts better fixing false categorisation of : as binary
checkpatch: ensure we do not collapse bracketed sections into constants
checkpatch: suggest cleanpatch and cleanfile when appropriate
checkpatch: types may sit on a line on their own
checkpatch: fix regressions in "fix handling of leading spaces"
div64_u64(): improve precision on 32bit platforms
lib/parser: cleanup match_number()
...
Add warnings for possible missing const uses of
static char foo[] = "bar"
that could be
static const char foo[] = "bar"
and
static const char *foo[] = {"bar", "baz"}
that could be
static const char * const foo[] = {"bar", "baz"}
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Mike Frysinger <vapier.adi@gmail.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When tracking context to find a block or statement we need to use the
sanitised lines, else perentheses '(' & ')' and braces '{' & '}' can throw
the scanner out. Also fix up a couple of error outputs which include
those sanitised lines incorrectly.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Handly definitions similar to below. The definition macro spits out a
symbol with a prefix. Add matching of any identifier prefix:
DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
ata_scsi_lpm_show, ata_scsi_lpm_put);
EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Handle definitions such as the following correctly, it is not
a complex statement:
#define PREALLOC(NAME, START, END, FLAGS) { \
.name = (NAME), \
.start = (START), \
.end = (END), \
.flags = (FLAGS) \
},
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On Wed, 2010-08-11 at 12:35 -0400, Dave Jones wrote:
> I just got this from a patch I merged..
>
> ERROR: need consistent spacing around '*' (ctx:WxV)
> #121: FILE: arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c:113:
> +static struct pcc_cpu __percpu *pcc_cpu_info;
> ^
> which doesn't seem right.
Perhaps these need to be added to checkpatch.
[apw@canonical.com: added tests]
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Throw an error when a source file has been given execute permissions using
the mode change line present in git diffs. Also alow the filename
matching to use the "diff" line in addition to the "+++" line, since the
mode change lines appear before any "+++" lines.
[apw@canonical.com: simplified filename logic slightly, added tests]
Cc: Andy Whitcroft <apw@canonical.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When checking the length of the help we need to be sure we are seeing the
whole story before erroring. Firstly we only want to check when adding
the help in the first place. Second we need to be sure that we are seeing
the end of the entry, nominally when there is no context below or that
context shows the start of the next entry.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commonise the code for missing spaces after struct, union, and enum such
that they share the same code. Ensure we cover all the common cases in
each case. Check against the sanitised line to ensure we do not report on
comments and strings.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add spacing checks for struct, union, and enum definitions. Check the
spacing after type and before the equals (=) and open brace ({).
Based on a patch by Joe Perches.
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a (strict mode only) test to check for non-negative returns of what
appear to be errno values as the majority case these should indeed be
negative.
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following incantation is triggering categorisation of its colon (:) as
a binary form, which it is not:
return foo ? (s8)bar : baz;
Handle casts differently from types in the categoriser, allowing us to
better track (s8)bar as a value and not a declaration.
Reported-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When determining if a return () sequence is a function style bracketing we
simplify the expression one bracket at a time replacing each with a
constant. However this can trigger a false merge with expressions as
below:
return (foo)0;
Prevent this false merging.
Reported-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we hit types of whitespace which may be fixed by scripts/cleanpatch
and scripts/cleanfile suggest their use in our report.
Suggested-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the following form is used we have a type which fully fills a line.
This means that a type may end at the end of line as well as at the
following identifier.
int **
foo;
Reported-by: Daniel Walker <dwalker@fifo99.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The patch "checkpatch: fix handling of leading spaces" added checks for
leading spaces on lines, but this introduces regressions. Firstly it does
not correctly detect when we are in a comment. Secondly it does not allow
for preprocessor command spacing. Finally it does not allow for label
indentation which is required to be less than one tab. Fix these up:
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current implementation of div64_u64 for 32bit systems returns an
approximately correct result when the divisor exceeds 32bits. Since doing
64bit division using 32bit hardware is a long since solved problem we just
use one of the existing proven methods.
Additionally, add a div64_s64 function to correctly handle doing signed
64bit division.
Addresses https://bugzilla.redhat.com/show_bug.cgi?id=616105
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ben Woodard <bwoodard@llnl.gov>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Mark Grondona <mgrondona@llnl.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use new variable 'len' to make code more readable.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
this_cpu_ptr() avoids an array lookup and can use the percpu offset of the
local cpu directly.
Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Improve 'lib_sort()' test and check that:
o 'cmp()' is called only for elements which were present in the original list,
i.e., the 'a' and 'b' parameters are valid
o the resulted (sorted) list consists onlly of the original elements
o intdoruce "poison" fields to make sure data around 'struc list_head' field
are not corrupted.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: Don Mullis <don.mullis@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch unifies 'list_sort_test()' messages a bit and makes sure all of
them start with the "list_sort_test:" prefix to make it obvious for users
where the messages come from.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: Don Mullis <don.mullis@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The 'lib_sort()' test does not free memory if it fails, and it makes the
kernel panic if it cannot allocate memory. This patch fixes the problem.
This patch also changes several small things:
o use 'list_add()' helper instead of adding manually
o introduce temporary 'el1' variable to avoid ugly and unreadalbe
"if" statement
o make 'head' to be stack variable instead of 'kmalloc()'ed, which
simplifies code a bit
Overall, this patch is of clean-up type.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: Don Mullis <don.mullis@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of using own pseudo-random generator, use generic linux
'random32()' function. Presumably, this should improve test coverage.
At the same time, do the following changes:
o Use shorter macro name for test list length
o Do not use strange 'l_h' name for 'struct list_head' element,
use 'list', because it is traditional name and thus, makes the
code more obvious and readable.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: Don Mullis <don.mullis@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I do not see any reason to use KERN_WARN for normal messages and
KERN_EMERG for error messages in the lib_sort testing routine. Let's use
more reasonable KERN_NORM and KERN_ERR levels.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: Don Mullis <don.mullis@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While hunting a non-existing bug in 'list_sort()', I've improved the
'list_sort_test()' function which tests the 'list_sort()' library call.
Although at the end I found a bug in my code, but not in 'list_sort()', I
think my clean-ups and improvements are worth merging because they make
the test function better.
This patch:
Make the self-tests selectable via Kconfig rather than by manual enabling
of DEBUG_LIST_SORT.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: Don Mullis <don.mullis@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All percpu counters are linked to a global list on initialization and
removed from it on destruction. The list is walked during CPU up/down.
If a percpu counter is freed without being properly destroyed, the system
will oops only on the next CPU up/down making it pretty nasty to track
down. This patch adds debugobj support for percpu counters so that such
problems can be found easily.
As percpu counters don't make sense on stack and can't be statically
initialized, debugobj support is pretty simple. It's initialized and
activated on counter initialization, and deactivatd and destroyed on
counter destruction. With this patch applied, the bug fixed by commit
602586a83b (shmem: put_super must
percpu_counter_destroy) triggers the following warning on tmpfs unmount
and the system won't oops on the next cpu up/down operation.
------------[ cut here ]------------
WARNING: at lib/debugobjects.c:259 debug_print_object+0x5c/0x70()
Hardware name: Bochs
ODEBUG: free active (active state 0) object type: percpu_counter
Modules linked in:
Pid: 3999, comm: umount Not tainted 2.6.36-rc2-work+ #5
Call Trace:
[<ffffffff81083f7f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff81084076>] warn_slowpath_fmt+0x46/0x50
[<ffffffff813b45cc>] debug_print_object+0x5c/0x70
[<ffffffff813b50e5>] debug_check_no_obj_freed+0x125/0x210
[<ffffffff811577d3>] kfree+0xb3/0x2f0
[<ffffffff81132edd>] shmem_put_super+0x1d/0x30
[<ffffffff81162e96>] generic_shutdown_super+0x56/0xe0
[<ffffffff81162f86>] kill_anon_super+0x16/0x60
[<ffffffff81162ff7>] kill_litter_super+0x27/0x30
[<ffffffff81163295>] deactivate_locked_super+0x45/0x60
[<ffffffff81163cfa>] deactivate_super+0x4a/0x70
[<ffffffff8117d446>] mntput_no_expire+0x86/0xe0
[<ffffffff8117df7f>] sys_umount+0x6f/0x360
[<ffffffff8103f01b>] system_call_fastpath+0x16/0x1b
---[ end trace cce2a341ba3611a7 ]---
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Thomas Gleixner <tglxlinutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Despite the idr_pre_get() kernel-doc, there are some cases where you can
call idr_pre_get() from within locked regions. Add a description for such
cases.
See also: http://lkml.org/lkml/2010/9/16/462
[akpm@linux-foundation.org: cleanups, grammatical fixes]
Signed-off-by: Naohiro Aota <naota@elisp.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
