07 May, 2019
1 commit
-
Pull stack trace updates from Ingo Molnar:
"So Thomas looked at the stacktrace code recently and noticed a few
weirdnesses, and we all know how such stories of crummy kernel code
meeting German engineering perfection end: a 45-patch series to clean
it all up! :-)Here's the changes in Thomas's words:
'Struct stack_trace is a sinkhole for input and output parameters
which is largely pointless for most usage sites. In fact if embedded
into other data structures it creates indirections and extra storage
overhead for no benefit.Looking at all usage sites makes it clear that they just require an
interface which is based on a storage array. That array is either on
stack, global or embedded into some other data structure.Some of the stack depot usage sites are outright wrong, but
fortunately the wrongness just causes more stack being used for
nothing and does not have functional impact.Another oddity is the inconsistent termination of the stack trace
with ULONG_MAX. It's pointless as the number of entries is what
determines the length of the stored trace. In fact quite some call
sites remove the ULONG_MAX marker afterwards with or without nasty
comments about it. Not all architectures do that and those which do,
do it inconsistenly either conditional on nr_entries == 0 or
unconditionally.The following series cleans that up by:
1) Removing the ULONG_MAX termination in the architecture code
2) Removing the ULONG_MAX fixups at the call sites
3) Providing plain storage array based interfaces for stacktrace
and stackdepot.4) Cleaning up the mess at the callsites including some related
cleanups.5) Removing the struct stack_trace based interfaces
This is not changing the struct stack_trace interfaces at the
architecture level, but it removes the exposure to the generic
code'"* 'core-stacktrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
x86/stacktrace: Use common infrastructure
stacktrace: Provide common infrastructure
lib/stackdepot: Remove obsolete functions
stacktrace: Remove obsolete functions
livepatch: Simplify stack trace retrieval
tracing: Remove the last struct stack_trace usage
tracing: Simplify stack trace retrieval
tracing: Make ftrace_trace_userstack() static and conditional
tracing: Use percpu stack trace buffer more intelligently
tracing: Simplify stacktrace retrieval in histograms
lockdep: Simplify stack trace handling
lockdep: Remove save argument from check_prev_add()
lockdep: Remove unused trace argument from print_circular_bug()
drm: Simplify stacktrace handling
dm persistent data: Simplify stack trace handling
dm bufio: Simplify stack trace retrieval
btrfs: ref-verify: Simplify stack trace retrieval
dma/debug: Simplify stracktrace retrieval
fault-inject: Simplify stacktrace retrieval
mm/page_owner: Simplify stack trace handling
...
29 Apr, 2019
1 commit
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Replace the indirection through struct stack_trace by using the storage
array based interfaces.Signed-off-by: Thomas Gleixner
Reviewed-by: Josh Poimboeuf
Acked-by: Catalin Marinas
Cc: Andy Lutomirski
Cc: linux-mm@kvack.org
Cc: Steven Rostedt
Cc: Alexander Potapenko
Cc: Alexey Dobriyan
Cc: Andrew Morton
Cc: Christoph Lameter
Cc: Pekka Enberg
Cc: David Rientjes
Cc: Dmitry Vyukov
Cc: Andrey Ryabinin
Cc: kasan-dev@googlegroups.com
Cc: Mike Rapoport
Cc: Akinobu Mita
Cc: Christoph Hellwig
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy
Cc: Marek Szyprowski
Cc: Johannes Thumshirn
Cc: David Sterba
Cc: Chris Mason
Cc: Josef Bacik
Cc: linux-btrfs@vger.kernel.org
Cc: dm-devel@redhat.com
Cc: Mike Snitzer
Cc: Alasdair Kergon
Cc: Daniel Vetter
Cc: intel-gfx@lists.freedesktop.org
Cc: Joonas Lahtinen
Cc: Maarten Lankhorst
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie
Cc: Jani Nikula
Cc: Rodrigo Vivi
Cc: Tom Zanussi
Cc: Miroslav Benes
Cc: linux-arch@vger.kernel.org
Link: https://lkml.kernel.org/r/20190425094801.863716911@linutronix.de
20 Apr, 2019
1 commit
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The only references outside of the #ifdef have been removed, so now we
get a warning in non-SMP configurations:mm/kmemleak.c:1404:13: error: unused function 'scan_large_block' [-Werror,-Wunused-function]
Add a new #ifdef around it.
Link: http://lkml.kernel.org/r/20190416123148.3502045-1-arnd@arndb.de
Fixes: 298a32b13208 ("kmemleak: powerpc: skip scanning holes in the .bss section")
Signed-off-by: Arnd Bergmann
Acked-by: Catalin Marinas
Cc: Vincent Whitchurch
Cc: Michael Ellerman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Apr, 2019
1 commit
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Commit 2d4f567103ff ("KVM: PPC: Introduce kvm_tmp framework") adds
kvm_tmp[] into the .bss section and then free the rest of unused spaces
back to the page allocator.kernel_init
kvm_guest_init
kvm_free_tmp
free_reserved_area
free_unref_page
free_unref_page_prepareWith DEBUG_PAGEALLOC=y, it will unmap those pages from kernel. As the
result, kmemleak scan will trigger a panic when it scans the .bss
section with unmapped pages.This patch creates dedicated kmemleak objects for the .data, .bss and
potentially .data..ro_after_init sections to allow partial freeing via
the kmemleak_free_part() in the powerpc kvm_free_tmp() function.Link: http://lkml.kernel.org/r/20190321171917.62049-1-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas
Reported-by: Qian Cai
Acked-by: Michael Ellerman (powerpc)
Tested-by: Qian Cai
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Cc: Avi Kivity
Cc: Paolo Bonzini
Cc: Radim Krcmar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Feb, 2019
1 commit
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kmemleak keeps two global variables, min_addr and max_addr, which store
the range of valid (encountered by kmemleak) pointer values, which it
later uses to speed up pointer lookup when scanning blocks.With tagged pointers this range will get bigger than it needs to be. This
patch makes kmemleak untag pointers before saving them to min_addr and
max_addr and when performing a lookup.Link: http://lkml.kernel.org/r/16e887d442986ab87fe87a755815ad92fa431a5f.1550066133.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov
Tested-by: Qian Cai
Acked-by: Catalin Marinas
Cc: Alexander Potapenko
Cc: Andrey Ryabinin
Cc: Christoph Lameter
Cc: David Rientjes
Cc: Dmitry Vyukov
Cc: Evgeniy Stepanov
Cc: Joonsoo Kim
Cc: Kostya Serebryany
Cc: Pekka Enberg
Cc: Vincenzo Frascino
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Dec, 2018
2 commits
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Kmemleak scan can be cpu intensive and can stall user tasks at times. To
prevent this, add config DEBUG_KMEMLEAK_AUTO_SCAN to enable/disable auto
scan on boot up. Also protect first_run with DEBUG_KMEMLEAK_AUTO_SCAN as
this is meant for only first automatic scan.Link: http://lkml.kernel.org/r/1540231723-7087-1-git-send-email-prpatel@nvidia.com
Signed-off-by: Sri Krishna chowdary
Signed-off-by: Sachin Nikam
Signed-off-by: Prateek
Reviewed-by: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
kmemleak_scan() goes through all online nodes and tries to scan all used
pages.We can do better and use pfn_to_online_page(), so in case we have
CONFIG_MEMORY_HOTPLUG, offlined pages will be skiped automatically. For
boxes where CONFIG_MEMORY_HOTPLUG is not present, pfn_to_online_page()
will fallback to pfn_valid().Another little optimization is to check if the page belongs to the node we
are currently checking, so in case we have nodes interleaved we will not
check the same pfn multiple times.I ran some tests:
Add some memory to node1 and node2 making it interleaved:
(qemu) object_add memory-backend-ram,id=ram0,size=1G
(qemu) device_add pc-dimm,id=dimm0,memdev=ram0,node=1
(qemu) object_add memory-backend-ram,id=ram1,size=1G
(qemu) device_add pc-dimm,id=dimm1,memdev=ram1,node=2
(qemu) object_add memory-backend-ram,id=ram2,size=1G
(qemu) device_add pc-dimm,id=dimm2,memdev=ram2,node=1Then, we offline that memory:
# for i in {32..39} ; do echo "offline" > /sys/devices/system/node/node1/memory$i/state;done
# for i in {48..55} ; do echo "offline" > /sys/devices/system/node/node1/memory$i/state;don
# for i in {40..47} ; do echo "offline" > /sys/devices/system/node/node2/memory$i/state;doneAnd we run kmemleak_scan:
# echo "scan" > /sys/kernel/debug/kmemleak
before the patch:
kmemleak: time spend: 41596 us
after the patch:
kmemleak: time spend: 34899 us
[akpm@linux-foundation.org: remove stray newline, per Oscar]
Link: http://lkml.kernel.org/r/20181206131918.25099-1-osalvador@suse.de
Signed-off-by: Oscar Salvador
Reviewed-by: Wei Yang
Suggested-by: Michal Hocko
Acked-by: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Oct, 2018
1 commit
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Move remaining definitions and declarations from include/linux/bootmem.h
into include/linux/memblock.h and remove the redundant header.The includes were replaced with the semantic patch below and then
semi-automated removal of duplicated '#include@@
@@
- #include
+ #include[sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h]
Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au
[sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h]
Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au
[sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal]
Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au
Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport
Signed-off-by: Stephen Rothwell
Acked-by: Michal Hocko
Cc: Catalin Marinas
Cc: Chris Zankel
Cc: "David S. Miller"
Cc: Geert Uytterhoeven
Cc: Greentime Hu
Cc: Greg Kroah-Hartman
Cc: Guan Xuetao
Cc: Ingo Molnar
Cc: "James E.J. Bottomley"
Cc: Jonas Bonn
Cc: Jonathan Corbet
Cc: Ley Foon Tan
Cc: Mark Salter
Cc: Martin Schwidefsky
Cc: Matt Turner
Cc: Michael Ellerman
Cc: Michal Simek
Cc: Palmer Dabbelt
Cc: Paul Burton
Cc: Richard Kuo
Cc: Richard Weinberger
Cc: Rich Felker
Cc: Russell King
Cc: Serge Semin
Cc: Thomas Gleixner
Cc: Tony Luck
Cc: Vineet Gupta
Cc: Yoshinori Sato
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Oct, 2018
1 commit
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Currently, kmemleak only prints the number of suspected leaks to dmesg but
requires the user to read a debugfs file to get the actual stack traces of
the objects' allocation points. Add a module option to print the full
object information to dmesg too. It can be enabled with
kmemleak.verbose=1 on the kernel command line, or "echo 1 >
/sys/module/kmemleak/parameters/verbose":This allows easier integration of kmemleak into test systems: We have
automated test infrastructure to test our Linux systems. With this
option, running our tests with kmemleak is as simple as enabling kmemleak
and passing this command line option; the test infrastructure knows how to
save kernel logs, which will now include kmemleak reports. Without this
option, the test infrastructure needs to be specifically taught to read
out the kmemleak debugfs file. Removing this need for special handling
makes kmemleak more similar to other kernel debug options (slab debugging,
debug objects, etc).Link: http://lkml.kernel.org/r/20180903144046.21023-1-vincent.whitchurch@axis.com
Signed-off-by: Vincent Whitchurch
Acked-by: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Sep, 2018
1 commit
-
If kmemleak built in to the kernel, but is disabled by default, the
debugfs file is never registered. Because of this, it is not possible
to find out if the kernel is built with kmemleak support by checking for
the presence of this file. To allow this, always register the file.After this patch, if the file doesn't exist, kmemleak is not available
in the kernel. If writing "scan" or any other value than "clear" to
this file results in EBUSY, then kmemleak is available but is disabled
by default and can be activated via the kernel command line.Catalin: "that's also consistent with a late disabling of kmemleak when
the debugfs entry sticks around."Link: http://lkml.kernel.org/r/20180824131220.19176-1-vincent.whitchurch@axis.com
Signed-off-by: Vincent Whitchurch
Acked-by: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Apr, 2018
2 commits
-
Link: http://lkml.kernel.org/r/1519585191-10180-4-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport
Reviewed-by: Andrew Morton
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The early_param() is only called during kernel initialization, So Linux
marks the functions of it with __init macro to save memory.But it forgot to mark the kmemleak_boot_config(). So, Make it __init as
well.Link: http://lkml.kernel.org/r/20180117034720.26897-1-douly.fnst@cn.fujitsu.com
Signed-off-by: Dou Liyang
Reviewed-by: Andrew Morton
Cc: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Mar, 2018
1 commit
-
A crash is observed when kmemleak_scan accesses the object->pointer,
likely due to the following race.TASK A TASK B TASK C
kmemleak_write
(with "scan" and
NOT "scan=on")
kmemleak_scan()
create_object
kmem_cache_alloc fails
kmemleak_disable
kmemleak_do_cleanup
kmemleak_free_enabled = 0
kfree
kmemleak_free bails out
(kmemleak_free_enabled is 0)
slub frees object->pointer
update_checksum
crash - object->pointer
freed (DEBUG_PAGEALLOC)kmemleak_do_cleanup waits for the scan thread to complete, but not for
direct call to kmemleak_scan via kmemleak_write. So add a wait for
kmemleak_scan completion before disabling kmemleak_free, and while at it
fix the comment on stop_scan_thread.[vinmenon@codeaurora.org: fix stop_scan_thread comment]
Link: http://lkml.kernel.org/r/1522219972-22809-1-git-send-email-vinmenon@codeaurora.org
Link: http://lkml.kernel.org/r/1522063429-18992-1-git-send-email-vinmenon@codeaurora.org
Signed-off-by: Vinayak Menon
Reviewed-by: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Feb, 2018
1 commit
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Preempt counter APIs have been split out, currently, hardirq.h just
includes irq_enter/exit APIs which are not used by kmemleak at all.So, remove the unused hardirq.h.
Link: http://lkml.kernel.org/r/1510959741-31109-1-git-send-email-yang.s@alibaba-inc.com
Signed-off-by: Yang Shi
Cc: Michal Hocko
Cc: Matthew Wilcox
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Jan, 2018
1 commit
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kmemleak does one slab allocation per user allocation. So if slab fault
injection is enabled to any degree, kmemleak instantly fails to allocate
and turns itself off. However, it's useful to use kmemleak with fault
injection to find leaks on error paths. On the other hand, checking
kmemleak itself is not so useful because (1) it's a debugging tool and
(2) it has a very regular allocation pattern (basically a single
allocation site, so it either works or not).Turn off fault injection for kmemleak allocations.
Link: http://lkml.kernel.org/r/20180109192243.19316-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov
Cc: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Dec, 2017
1 commit
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Commit bde5f6bc68db ("kmemleak: add scheduling point to
kmemleak_scan()") tries to rate-limit the frequency of cond_resched()
calls, but does it in a way which might incur an expensive division
operation in the inner loop. Simplify this.Fixes: bde5f6bc68db5 ("kmemleak: add scheduling point to kmemleak_scan()")
Suggested-by: Linus Torvalds
Cc: Yisheng Xie
Cc: Catalin Marinas
Cc: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Nov, 2017
1 commit
-
kmemleak_scan() will scan struct page for each node and it can be really
large and resulting in a soft lockup. We have seen a soft lockup when
do scan while compile kernel:watchdog: BUG: soft lockup - CPU#53 stuck for 22s! [bash:10287]
[...]
Call Trace:
kmemleak_scan+0x21a/0x4c0
kmemleak_write+0x312/0x350
full_proxy_write+0x5a/0xa0
__vfs_write+0x33/0x150
vfs_write+0xad/0x1a0
SyS_write+0x52/0xc0
do_syscall_64+0x61/0x1a0
entry_SYSCALL64_slow_path+0x25/0x25Fix this by adding cond_resched every MAX_SCAN_SIZE.
Link: http://lkml.kernel.org/r/1511439788-20099-1-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Yisheng Xie
Suggested-by: Catalin Marinas
Acked-by: Catalin Marinas
Cc: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Nov, 2017
2 commits
-
Patch series "kmemcheck: kill kmemcheck", v2.
As discussed at LSF/MM, kill kmemcheck.
KASan is a replacement that is able to work without the limitation of
kmemcheck (single CPU, slow). KASan is already upstream.We are also not aware of any users of kmemcheck (or users who don't
consider KASan as a suitable replacement).The only objection was that since KASAN wasn't supported by all GCC
versions provided by distros at that time we should hold off for 2
years, and try again.Now that 2 years have passed, and all distros provide gcc that supports
KASAN, kill kmemcheck again for the very same reasons.This patch (of 4):
Remove kmemcheck annotations, and calls to kmemcheck from the kernel.
[alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs]
Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com
Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.com
Signed-off-by: Sasha Levin
Cc: Alexander Potapenko
Cc: Eric W. Biederman
Cc: Michal Hocko
Cc: Pekka Enberg
Cc: Steven Rostedt
Cc: Tim Hansen
Cc: Vegard Nossum
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Kmemleak can be tweaked at runtime by writing commands into debugfs
file. Root can use it anyway, but without the write-bit this interface
isn't obvious.Link: http://lkml.kernel.org/r/150728996582.744328.11541332857988399411.stgit@buzz
Signed-off-by: Konstantin Khlebnikov
Acked-by: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Jul, 2017
3 commits
-
Kmemleak requires that vmalloc'ed objects have a minimum reference count
of 2: one in the corresponding vm_struct object and the other owned by
the vmalloc() caller. There are cases, however, where the original
vmalloc() returned pointer is lost and, instead, a pointer to vm_struct
is stored (see free_thread_stack()). Kmemleak currently reports such
objects as leaks.This patch adds support for treating any surplus references to an object
as additional references to a specified object. It introduces the
kmemleak_vmalloc() API function which takes a vm_struct pointer and sets
its surplus reference passing to the actual vmalloc() returned pointer.
The __vmalloc_node_range() calling site has been modified accordingly.Link: http://lkml.kernel.org/r/1495726937-23557-4-git-send-email-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas
Reported-by: "Luis R. Rodriguez"
Cc: Michal Hocko
Cc: Andy Lutomirski
Cc: "Luis R. Rodriguez"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
scan_block() updates the number of references (pointers) to objects,
adding them to the gray_list when object->min_count is reached. The
patch factors out this functionality into a separate update_refs()
function.Link: http://lkml.kernel.org/r/1495726937-23557-3-git-send-email-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas
Cc: Michal Hocko
Cc: Andy Lutomirski
Cc: "Luis R. Rodriguez"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Change the kmemleak_object.flags type to unsigned int and moves the
early_log.min_count (int) near early_log.op_type (int) to slightly
reduce the size of these structures on 64-bit architectures.Link: http://lkml.kernel.org/r/1495726937-23557-2-git-send-email-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas
Cc: Michal Hocko
Cc: Andy Lutomirski
Cc: "Luis R. Rodriguez"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Apr, 2017
1 commit
-
A section name for .data..ro_after_init was added by both:
commit d07a980c1b8d ("s390: add proper __ro_after_init support")
and
commit d7c19b066dcf ("mm: kmemleak: scan .data.ro_after_init")
The latter adds incorrect wrapping around the existing s390 section, and
came later. I'd prefer the s390 naming, so this moves the s390-specific
name up to the asm-generic/sections.h and renames the section as used by
kmemleak (and in the future, kernel/extable.c).Link: http://lkml.kernel.org/r/20170327192213.GA129375@beast
Signed-off-by: Kees Cook
Acked-by: Heiko Carstens [s390 parts]
Acked-by: Jakub Kicinski
Cc: Eddie Kovsky
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Mar, 2017
3 commits
-
We are going to split out of , which
will have to be picked up from other headers and a couple of .c files.Create a trivial placeholder file that just
maps to to make this patch obviously correct and
bisectable.Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar -
We are going to split out of , which
will have to be picked up from other headers and a couple of .c files.Create a trivial placeholder file that just
maps to to make this patch obviously correct and
bisectable.Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar -
We are going to split out of , which
will have to be picked up from other headers and a couple of .c files.Create a trivial placeholder file that just
maps to to make this patch obviously correct and
bisectable.Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar
13 Dec, 2016
1 commit
-
Documentation/kmemleak.txt was moved to Documentation/dev-tools/kmemleak.rst,
this fixes the reference to the new location.Link: http://lkml.kernel.org/r/1476544946-18804-1-git-send-email-andreas.platschek@opentech.at
Signed-off-by: Andreas Platschek
Acked-by: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Nov, 2016
1 commit
-
Limit the number of kmemleak false positives by including
.data.ro_after_init in memory scanning. To achieve this we need to add
symbols for start and end of the section to the linker scripts.The problem was been uncovered by commit 56989f6d8568 ("genetlink: mark
families as __ro_after_init").Link: http://lkml.kernel.org/r/1478274173-15218-1-git-send-email-jakub.kicinski@netronome.com
Reviewed-by: Catalin Marinas
Signed-off-by: Jakub Kicinski
Cc: Arnd Bergmann
Cc: Cong Wang
Cc: Johannes Berg
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Oct, 2016
1 commit
-
Commit 68f24b08ee89 ("sched/core: Free the stack early if
CONFIG_THREAD_INFO_IN_TASK") may cause the task->stack to be freed
during kmemleak_scan() execution, leading to either a NULL pointer fault
(if task->stack is NULL) or kmemleak accessing already freed memory.This patch uses the new try_get_task_stack() API to ensure that the task
stack is not freed during kmemleak stack scanning.Addresses https://bugzilla.kernel.org/show_bug.cgi?id=173901.
Fixes: 68f24b08ee89 ("sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK")
Link: http://lkml.kernel.org/r/1476266223-14325-1-git-send-email-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas
Reported-by: CAI Qian
Tested-by: CAI Qian
Acked-by: Michal Hocko
Cc: Andy Lutomirski
Cc: CAI Qian
Cc: Hillf Danton
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Oct, 2016
1 commit
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Some of the kmemleak_*() callbacks in memblock, bootmem, CMA convert a
physical address to a virtual one using __va(). However, such physical
addresses may sometimes be located in highmem and using __va() is
incorrect, leading to inconsistent object tracking in kmemleak.The following functions have been added to the kmemleak API and they take
a physical address as the object pointer. They only perform the
corresponding action if the address has a lowmem mapping:kmemleak_alloc_phys
kmemleak_free_part_phys
kmemleak_not_leak_phys
kmemleak_ignore_physThe affected calling places have been updated to use the new kmemleak
API.Link: http://lkml.kernel.org/r/1471531432-16503-1-git-send-email-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas
Reported-by: Vignesh R
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Jul, 2016
1 commit
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If the user tries to disable automatic scanning early in the boot
process using e.g.:echo scan=off > /sys/kernel/debug/kmemleak
then this command will hang until SECS_FIRST_SCAN (= 60) seconds have
elapsed, even though the system is fully initialised.We can fix this using interruptible sleep and checking if we're supposed
to stop whenever we wake up (like the rest of the code does).Link: http://lkml.kernel.org/r/1468835005-2873-1-git-send-email-vegard.nossum@oracle.com
Signed-off-by: Vegard Nossum
Acked-by: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Jun, 2016
1 commit
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When kmemleak dumps contents of leaked objects it reads whole objects
regardless of user-requested size. This upsets KASAN. Disable KASAN
checks around object dump.Link: http://lkml.kernel.org/r/1466617631-68387-1-git-send-email-dvyukov@google.com
Signed-off-by: Dmitry Vyukov
Acked-by: Catalin Marinas
Cc: Andrey Ryabinin
Cc: Alexander Potapenko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
18 Mar, 2016
2 commits
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Kernel style prefers a single string over split strings when the string is
'user-visible'.Miscellanea:
- Add a missing newline
- Realign argumentsSigned-off-by: Joe Perches
Acked-by: Tejun Heo [percpu]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
There are a mixture of pr_warning and pr_warn uses in mm. Use pr_warn
consistently.Miscellanea:
- Coalesce formats
- Realign argumentsSigned-off-by: Joe Perches
Acked-by: Tejun Heo [percpu]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Jan, 2016
1 commit
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This reverts commit 8f4fc071b192 ("gfp: add __GFP_NOACCOUNT").
Black-list kmem accounting policy (aka __GFP_NOACCOUNT) turned out to be
fragile and difficult to maintain, because there seem to be many more
allocations that should not be accounted than those that should be.
Besides, false accounting an allocation might result in much worse
consequences than not accounting at all, namely increased memory
consumption due to pinned dead kmem caches.So it was decided to switch to the white-list policy. This patch
reverts bits introducing the black-list policy. The white-list policy
will be introduced later in the series.Signed-off-by: Vladimir Davydov
Acked-by: Johannes Weiner
Cc: Michal Hocko
Cc: Tejun Heo
Cc: Greg Thelen
Cc: Christoph Lameter
Cc: Pekka Enberg
Cc: David Rientjes
Cc: Joonsoo Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Nov, 2015
1 commit
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Few lines below object is reinitialized by lookup_object() so we don't
need to init it by NULL in the beginning of find_and_get_object().Signed-off-by: Alexey Klimov
Acked-by: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Sep, 2015
1 commit
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Instead of custom approach let's use recently introduced seq_hex_dump()
helper.Signed-off-by: Andy Shevchenko
Cc: Alexander Viro
Cc: Joe Perches
Cc: Tadeusz Struk
Cc: Helge Deller
Cc: Ingo Tuchscherer
Acked-by: Catalin Marinas
Cc: Vladimir Kondratiev
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Sep, 2015
1 commit
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In log_early function, crt_early_log should also count once when
'crt_early_log >= ARRAY_SIZE(early_log)'. Otherwise the reported count
from kmemleak_init is one less than 'actual number'.Then, in kmemleak_init, if early_log buffer size equal actual number,
kmemleak will init sucessful, so change warning condition to
'crt_early_log > ARRAY_SIZE(early_log)'.Signed-off-by: Wang Kai
Acked-by: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Jun, 2015
2 commits
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Beginning at commit d52d3997f843 ("ipv6: Create percpu rt6_info"), the
following INFO splat is logged:===============================
[ INFO: suspicious RCU usage. ]
4.1.0-rc7-next-20150612 #1 Not tainted
-------------------------------
kernel/sched/core.c:7318 Illegal context switch in RCU-bh read-side critical section!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 0
3 locks held by systemd/1:
#0: (rtnl_mutex){+.+.+.}, at: [] rtnetlink_rcv+0x1f/0x40
#1: (rcu_read_lock_bh){......}, at: [] ipv6_add_addr+0x62/0x540
#2: (addrconf_hash_lock){+...+.}, at: [] ipv6_add_addr+0x184/0x540
stack backtrace:
CPU: 0 PID: 1 Comm: systemd Not tainted 4.1.0-rc7-next-20150612 #1
Hardware name: TOSHIBA TECRA A50-A/TECRA A50-A, BIOS Version 4.20 04/17/2014
Call Trace:
dump_stack+0x4c/0x6e
lockdep_rcu_suspicious+0xe7/0x120
___might_sleep+0x1d5/0x1f0
__might_sleep+0x4d/0x90
kmem_cache_alloc+0x47/0x250
create_object+0x39/0x2e0
kmemleak_alloc_percpu+0x61/0xe0
pcpu_alloc+0x370/0x630Additional backtrace lines are truncated. In addition, the above splat
is followed by several "BUG: sleeping function called from invalid
context at mm/slub.c:1268" outputs. As suggested by Martin KaFai Lau,
these are the clue to the fix. Routine kmemleak_alloc_percpu() always
uses GFP_KERNEL for its allocations, whereas it should follow the gfp
from its callers.Reviewed-by: Catalin Marinas
Reviewed-by: Kamalesh Babulal
Acked-by: Martin KaFai Lau
Signed-off-by: Larry Finger
Cc: Martin KaFai Lau
Cc: Catalin Marinas
Cc: Tejun Heo
Cc: Christoph Lameter
Cc: [3.18+]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The kmemleak memory scanning uses finer grained object->lock spinlocks
primarily to avoid races with the memory block freeing. However, the
pointer lookup in the rb tree requires the kmemleak_lock to be held.
This is currently done in the find_and_get_object() function for each
pointer-like location read during scanning. While this allows a low
latency on kmemleak_*() callbacks on other CPUs, the memory scanning is
slower.This patch moves the kmemleak_lock outside the scan_block() loop,
acquiring/releasing it only once per scanned memory block. The
allow_resched logic is moved outside scan_block() and a new
scan_large_block() function is implemented which splits large blocks in
MAX_SCAN_SIZE chunks with cond_resched() calls in-between. A redundant
(object->flags & OBJECT_NO_SCAN) check is also removed from
scan_object().With this patch, the kmemleak scanning performance is significantly
improved: at least 50% with lock debugging disabled and over an order of
magnitude with lock proving enabled (on an arm64 system).Signed-off-by: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
