An edit script should be considered inaccessible by a function once it has
called assoc_array_apply_edit() or assoc_array_cancel_edit().
However, assoc_array_gc() is accessing the edit script just after the
gc_complete: label.
Reported-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
cc: shemming@brocade.com
cc: paulmck@linux.vnet.ibm.com
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
I was puzzled why /proc/$$/stack had disappeared, until I figured out I
had disabled the last debug option that did a 'select STACKTRACE'. This
patch makes the option show up at config time, so it can be enabled
without enabling any of the more heavyweight debug options.
Signed-off-by: Dave Jones <davej@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We really don't want distro's enabling this in their kernels. Try and
make that more clear.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
No need to export rht_obj(), all inner to outer object translations
occur internally. It was intended to be used with rht_for_each() which
now primarily serves as the iterator for rhashtable_remove_pprev() to
effectively flush and free the full table.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Properly annotate next pointers as access is RCU protected in
the lookup path.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rather than have architectures #define ARCH_HAS_SG_CHAIN in an
architecture specific scatterlist.h, make it a proper Kconfig option and
use that instead. At same time, remove the header files are are now
mostly useless and just include asm-generic/scatterlist.h.
[sfr@canb.auug.org.au: powerpc files now need asm/dma.h]
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de> [x86]
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [powerpc]
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now with 64bit bzImage and kexec tools, we support ramdisk that size is
bigger than 2g, as we could put it above 4G.
Found compressed initramfs image could not be decompressed properly. It
turns out that image length is int during decompress detection, and it
will become < 0 when length is more than 2G. Furthermore, during
decompressing len as int is used for inbuf count, that has problem too.
Change len to long, that should be ok as on 32 bit platform long is
32bits.
Tested with following compressed initramfs image as root with kexec.
gzip, bzip2, xz, lzma, lzop, lz4.
run time for populate_rootfs():
size name Nehalem-EX Westmere-EX Ivybridge-EX
9034400256 root_img : 26s 24s 30s
3561095057 root_img.lz4 : 28s 27s 27s
3459554629 root_img.lzo : 29s 29s 28s
3219399480 root_img.gz : 64s 62s 49s
2251594592 root_img.xz : 262s 260s 183s
2226366598 root_img.lzma: 386s 376s 277s
2901482513 root_img.bz2 : 635s 599s
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rashika Kheria <rashika.kheria@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: P J P <ppandit@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: "Daniel M. Weeks" <dan@danweeks.net>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Cc: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During testing initrd (>2G) support, find decompress/lz4 does not work
with initrd at all.
decompress_* should support:
1. inbuf[]/outbuf[] for kernel preboot.
2. inbuf[]/flush() for initramfs
3. fill()/flush() for initrd.
in the unlz4 does not handle case 3, as input len is passed as 0, and it
failed in first try.
Fix that add one extra if (fill) checking, and get out if EOF from the
fill().
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use BUG_ON(x) rather than if(x) BUG();
The semantic patch that fixes this problem is as follows:
// <smpl>
@@ identifier x; @@
-if (!x) BUG();
+BUG_ON(!x);
// </smpl>
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Cc: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In case 1, it passes down the BLACK color from G to p and u, and maintains
the color of n. By doing so, it maintains the black height of the
sub-tree.
While in the comment, it marks the color of n to BLACK. This is a typo
and not consistents with the code.
This patch fixs this typo in comment.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Acked-by: Michel Lespinasse <walken@google.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I'm working on address sanitizer project for kernel. Recently we
started experiments with stack instrumentation, to detect out-of-bounds
read/write bugs on stack.
Just after booting I've hit out-of-bounds read on stack in idr_for_each
(and in __idr_remove_all as well):
struct idr_layer **paa = &pa[0];
while (id >= 0 && id <= max) {
...
while (n < fls(id)) {
n += IDR_BITS;
p = *--paa; <--- here we are reading pa[-1] value.
}
}
Despite the fact that after this dereference we are exiting out of loop
and never use p, such behaviour is undefined and should be avoided.
Fix this by moving pointer derference to the beggining of the loop,
right before we will use it.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Alexey Preobrazhensky <preobr@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Apparently, bitmap_andnot is supposed to return whether the new bitmap
is empty. But it didn't take potential garbage bits in the last word
into account.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Apparently, bitmap_and is supposed to return whether the new bitmap is
empty. But it didn't take potential garbage bits in the last word into
account.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__reg_op(..., REG_OP_ALLOC) always returns 0, so we might as well use that
and save an instruction.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Changing the pos parameter of __reg_op to unsigned allows the compiler
to generate slightly smaller and simpler code. Also update its callers
bitmap_*_region to receive and pass unsigned int. The return types of
bitmap_find_free_region and bitmap_allocate_region are still int to
allow a negative error code to be returned. An int is certainly capable
of representing any realistic return value.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A few lines above, it was stated that positions for non-set bits are
mapped to -1, which is obviously also what the code does.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We want len to be the index of the first '\n', or the length of the
string if there is no newline. This is a good example of the usefulness
of strchrnul(). Use that instead, thus eliminating a branch and a call
to strlen().
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The compiler can generate slightly smaller and simpler code when it
knows that "start" is non-negative.
Also, use the names "start" and "len" for the two parameters for
consistency with bitmap_set.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The compiler can generate slightly smaller and simpler code when it
knows that "start" is non-negative.
Also, use the names "start" and "len" for the two parameters in both
header file and implementation, instead of the previous mix.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The compiler can generate slightly smaller and simpler code when it
knows that "nbits" is non-negative. Since no-one passes a negative
bit-count, this shouldn't affect the semantics.
I didn't change the return type, since that might change the semantics
of some expression containing a call to bitmap_weight(). Certainly an
int is capable of holding the result.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The compiler can generate slightly smaller and simpler code when it
knows that "nbits" is non-negative. Since no-one passes a negative
bit-count, this shouldn't affect the semantics.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The compiler can generate slightly smaller and simpler code when it
knows that "nbits" is non-negative. Since no-one passes a negative
bit-count, this shouldn't affect the semantics.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This change is only for consistency with the changes to the other
bitmap_* functions; it doesn't change the size of the generated code:
inside BITS_TO_LONGS there is a sizeof(long), which causes bits to be
interpreted as unsigned anyway.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since the extra bits are "don't care", there is no reason to mask the
last word to the used bits when complementing. This shaves off yet a
few bytes.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The compiler can generate slightly smaller and simpler code when it
knows that "nbits" is non-negative. Since no-one passes a negative
bit-count, this shouldn't affect the semantics.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The compiler can generate slightly smaller and simpler code when it
knows that "nbits" is non-negative. Since no-one passes a negative
bit-count, this shouldn't affect the semantics.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The compiler can generate slightly smaller and simpler code when it
knows that "nbits" is non-negative. Since no-one passes a negative
bit-count, this shouldn't affect the semantics.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many functions in lib/bitmap.c start with an expression such as lim =
bits/BITS_PER_LONG. Since bits has type (signed) int, and since gcc
cannot know that it is in fact non-negative, it generates worse code
than it could. These patches, mostly consisting of changing various
parameters to unsigned, gives a slight overall code reduction:
add/remove: 1/1 grow/shrink: 8/16 up/down: 251/-414 (-163)
function old new delta
tick_device_uses_broadcast 335 425 +90
__irq_alloc_descs 498 554 +56
__bitmap_andnot 73 115 +42
__bitmap_and 70 101 +31
bitmap_weight - 11 +11
copy_hugetlb_page_range 752 762 +10
follow_hugetlb_page 846 854 +8
hugetlb_init 1415 1417 +2
hugetlb_nrpages_setup 130 131 +1
hugetlb_add_hstate 377 376 -1
bitmap_allocate_region 82 80 -2
select_task_rq_fair 2202 2191 -11
hweight_long 66 55 -11
__reg_op 230 219 -11
dm_stats_message 2849 2833 -16
bitmap_parselist 92 74 -18
__bitmap_weight 115 97 -18
__bitmap_subset 153 129 -24
__bitmap_full 128 104 -24
__bitmap_empty 120 96 -24
bitmap_set 179 149 -30
bitmap_clear 185 155 -30
__bitmap_equal 136 105 -31
__bitmap_intersects 148 108 -40
__bitmap_complement 109 67 -42
tick_device_setup_broadcast_func.isra 81 - -81
[The increases in __bitmap_and{,not} are due to bug fixes 17/18,18/18.
No idea why bitmap_weight suddenly appears.] While 163 bytes treewide is
insignificant, I believe the bitmap functions are often called with
locks held, so saving even a few cycles might be worth it.
While making these changes, I found a few other things that might be
worth including. 16,17,18 are actual bug fixes. The rest shouldn't
change the behaviour of any of the functions, provided no-one passed
negative nbits values. If something should come up, it should be fairly
bisectable.
A few issues I thought about, but didn't know what to do with:
* Many of the functions misbehave if nbits is compile-time 0; the
out-of-line functions generally handle 0 correctly. bitmap_fill() is
particularly bad, whether the 0 is known at compile time or not. It
would probably be nice to add detection of at least compile-time 0 and
handle that appropriately.
* I didn't change __bitmap_shift_{left,right} to use unsigned because I
want to fully understand why the algorithm works before making that
change. However, AFAICT, they behave correctly for all (positive) shift
amounts. This is not the case for the small_const_nbits versions. If
for example nbits = n = BITS_PER_LONG, the shift operators turn into
no-ops (at least on x86), so one get *dst = *src, whereas one would
expect to get *dst=0. That difference in behaviour is somewhat
annoying.
This patch (of 18):
The compiler can generate slightly smaller and simpler code when it
knows that "nbits" is non-negative. Since no-one passes a negative
bit-count, this shouldn't affect the semantics.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The helper merge_and_restore_back_links() makes sure to call the
caller's cmp function during the final ->prev pointer fixup, so that the
cmp function may call cond_resched(). However, if the cmp function does
not call cond_resched() at all, this is entirely redundant. If it does,
doing at least two function calls for every two pointer assignments is a
bit excessive. This patch limits the calls to once for every 256
iterations.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Don Mullis <don.mullis@gmail.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no reason to maintain the list structure while freeing the
debug elements. Aside from the redundant pointer manipulations, it is
also inefficient from a locality-of-reference viewpoint, since they are
visited in a random order (wrt. the order they were allocated).
Furthermore, if we jumped to exit: after detecting list corruption, it
is actually dangerous.
So just free the elements in the order they were allocated, using the
backing array elts. Allocate that using kcalloc(), so that if
allocation of one of the debug element fails, we just end up calling
kfree(NULL) for the trailing elements.
Minor details: Use sizeof(*elts) instead of sizeof(void *), and return
err immediately when allocation of elts fails, to avoid introducing
another label just before the final return statement.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Don Mullis <don.mullis@gmail.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a check to make sure that the prev pointer of the list head points
to the last element on the list.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Don Mullis <don.mullis@gmail.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Complement commit 68aecfb979 ("lib/string_helpers.c: make arrays
static") by making the arrays const -- not only pointing to const
strings. This moves them out of the data section to the r/o data
section:
text data bss dec hex filename
1150 176 0 1326 52e lib/string_helpers.old.o
1326 0 0 1326 52e lib/string_helpers.new.o
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For modern filesystems such as btrfs, t/p/e size level operations are
common. add size unit t/p/e parsing to memparse
Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was useful during development, and is retained for future
regression testing.
GCC appears to have no way to place string literals in a particular
section; adding __initconst to a char pointer leaves the string itself
in the default string section, where it will not be thrown away after
module load.
Thus all string constants are kept in explicitly declared and named
arrays. Sorry this makes printk a bit harder to read. At least the
tests are more compact.
Signed-off-by: George Spelvin <linux@horizon.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a helper function from drivers/ata/libata_core.c, where it is
used to blacklist particular device models. It's being moved to lib/ so
other drivers may use it for the same purpose.
This implementation in non-recursive, so is safe for the kernel stack.
[akpm@linux-foundation.org: fix sparse warning]
Signed-off-by: George Spelvin <linux@horizon.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleanup unused `if 0'-ed functions, which have been dead since 2006
(commits 87c2ce3b93 ("lib/zlib*: cleanups") by Adrian Bunk and
4f3865fb57 ("zlib_inflate: Upgrade library code to a recent version")
by Richard Purdie):
- zlib_deflateSetDictionary
- zlib_deflateParams
- zlib_deflateCopy
- zlib_inflateSync
- zlib_syncsearch
- zlib_inflateSetDictionary
- zlib_inflatePrime
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The name was modified from hlist_add_after() to hlist_add_behind() when
adjusting the order of arguments to match the one with
klist_add_after(). This is necessary to break old code when it would
use it the wrong way.
Make klist follow this naming scheme for consistency.
Signed-off-by: Ken Helias <kenhelias@firemail.de>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit a8fe19ebfb ("kernel/printk: use symbolic defines for console
loglevels") makes consistent use of symbolic values for printk() log
levels.
The naming scheme used is different from the one used for
DEFAULT_MESSAGE_LOGLEVEL though. Change that symbol name to be
MESSAGE_LOGLEVEL_DEFAULT for consistency. And because the value of that
symbol comes from a similarly-named config option, rename
CONFIG_DEFAULT_MESSAGE_LOGLEVEL as well.
Signed-off-by: Alex Elder <elder@linaro.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jan Kara <jack@suse.cz>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Generic implementation of a resizable, scalable, concurrent hash table
based on [0]. The implementation supports both, fixed size keys specified
via an offset and length, or arbitrary keys via own hash and compare
functions.
Lookups are lockless and protected as RCU read side critical sections.
Automatic growing/shrinking based on user configurable watermarks is
available while allowing concurrent lookups to take place.
Objects to be hashed must include a struct rhash_head. The reason for not
using the existing struct hlist_head is that the expansion and shrinking
will have two buckets point to a single entry which would lead in obscure
reverse chaining behaviour.
Code includes a boot selftest if CONFIG_TEST_RHASHTABLE is defined.
[0] https://www.usenix.org/legacy/event/atc11/tech/final_files/Triplett.pdf
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Reviewed-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Check for cases when the caller requests 0 bytes instead of running off
and dereferencing potentially invalid iovecs.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
clean up names related to socket filtering and bpf in the following way:
- everything that deals with sockets keeps 'sk_*' prefix
- everything that is pure BPF is changed to 'bpf_*' prefix
split 'struct sk_filter' into
struct sk_filter {
atomic_t refcnt;
struct rcu_head rcu;
struct bpf_prog *prog;
};
and
struct bpf_prog {
u32 jited:1,
len:31;
struct sock_fprog_kern *orig_prog;
unsigned int (*bpf_func)(const struct sk_buff *skb,
const struct bpf_insn *filter);
union {
struct sock_filter insns[0];
struct bpf_insn insnsi[0];
struct work_struct work;
};
};
so that 'struct bpf_prog' can be used independent of sockets and cleans up
'unattached' bpf use cases
split SK_RUN_FILTER macro into:
SK_RUN_FILTER to be used with 'struct sk_filter *' and
BPF_PROG_RUN to be used with 'struct bpf_prog *'
__sk_filter_release(struct sk_filter *) gains
__bpf_prog_release(struct bpf_prog *) helper function
also perform related renames for the functions that work
with 'struct bpf_prog *', since they're on the same lines:
sk_filter_size -> bpf_prog_size
sk_filter_select_runtime -> bpf_prog_select_runtime
sk_filter_free -> bpf_prog_free
sk_unattached_filter_create -> bpf_prog_create
sk_unattached_filter_destroy -> bpf_prog_destroy
sk_store_orig_filter -> bpf_prog_store_orig_filter
sk_release_orig_filter -> bpf_release_orig_filter
__sk_migrate_filter -> bpf_migrate_filter
__sk_prepare_filter -> bpf_prepare_filter
API for attaching classic BPF to a socket stays the same:
sk_attach_filter(prog, struct sock *)/sk_detach_filter(struct sock *)
and SK_RUN_FILTER(struct sk_filter *, ctx) to execute a program
which is used by sockets, tun, af_packet
API for 'unattached' BPF programs becomes:
bpf_prog_create(struct bpf_prog **)/bpf_prog_destroy(struct bpf_prog *)
and BPF_PROG_RUN(struct bpf_prog *, ctx) to execute a program
which is used by isdn, ppp, team, seccomp, ptp, xt_bpf, cls_bpf, test_bpf
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I found that a lot of unresolvable variables when using gdb on the
kernel become resolvable when dwarf4 is enabled. So add a Kconfig flag
to enable it.
It definitely increases the debug information size, but on the other
hand this isn't so bad when debug fusion is used.
v2: Use cc-option
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Currently, we have a 3-stage seeding process in prandom():
Phase 1 is from the early actual initialization of prandom()
subsystem which happens during core_initcall() and remains
most likely until the beginning of late_initcall() phase.
Here, the system might not have enough entropy available
for seeding with strong randomness from the random driver.
That means, we currently have a 32bit weak LCG() seeding
the PRNG status register 1 and mixing that successively
into the other 3 registers just to get it up and running.
Phase 2 starts with late_initcall() phase resp. when the
random driver has initialized its non-blocking pool with
enough entropy. At that time, we throw away *all* inner
state from its 4 registers and do a full reseed with strong
randomness.
Phase 3 starts right after that and does a periodic reseed
with random slack of status register 1 by a strong random
source again.
A problem in phase 1 is that during bootup data structures
can be initialized, e.g. on module load time, and thus access
a weakly seeded prandom and are never changed for the rest
of their live-time, thus carrying along the results from a
week seed. Lets make sure that current but also future users
access a possibly better early seeded prandom.
This patch therefore improves phase 1 by trying to make it
more 'unpredictable' through mixing in seed from a possible
hardware source. Now, the mix-in xors inner state with the
outcome of either of the two functions arch_get_random_{,seed}_int(),
preferably arch_get_random_seed_int() as it likely represents
a non-deterministic random bit generator in hw rather than
a cryptographically secure PRNG in hw. However, not all might
have the first one, so we use the PRNG as a fallback if
available. As we xor the seed into the current state, the
worst case would be that a hardware source could be unverifiable
compromised or backdoored. In that case nevertheless it
would be as good as our original early seeding function
prandom_seed_very_weak() since we mix through xor which is
entropy preserving.
Joint work with Daniel Borkmann.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is an alternative approach to lower the overhead of debug info
(as we discussed a few days ago)
gcc 4.7+ and newer binutils have a new "split debug info" debug info
model where the debug info is only written once into central ".dwo" files.
This avoids having to copy it around multiple times, from the object
files to the final executable. It lowers the disk space
requirements. In addition it defaults to compressed debug data.
More details here: http://gcc.gnu.org/wiki/DebugFission
This patch adds a new option to enable it. It has to be an option,
because it'll undoubtedly break everyone's debuginfo packaging scheme.
gdb/objdump/etc. all still work, if you have new enough versions.
I don't see big compile wins (maybe a second or two faster or so), but the
object dirs with debuginfo get significantly smaller. My standard kernel
config (slightly bigger than defconfig) shrinks from 2.9G disk space
to 1.1G objdir (with non reduced debuginfo). I presume if you are IO limited
the compile time difference will be larger.
Only problem I've seen so far is that it doesn't play well with older
versions of ccache (apparently fixed, see
https://bugzilla.samba.org/show_bug.cgi?id=10005)
v2: various fixes from Dirk Gouders. Improve commit message slightly.
v3: Fix clean rules and improve Kconfig slightly
v4: Fix merge error in last version (Sam Ravnborg)
Clarify description that it mainly helps disk size.
Cc: Dirk Gouders <dirk@gouders.net>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Blk-mq drivers usually preallocate their S/G list as part of the request,
but if we want to support the very large S/G lists currently supported by
the SCSI code that would tie up a lot of memory in the preallocated request
pool. Add support to the scatterlist code so that it can initialize a
S/G list that uses a preallocated first chunks and dynamically allocated
additional chunks. That way the scsi-mq code can preallocate a first
page worth of S/G entries as part of the request, and dynamically extend
the S/G list when needed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
eBPF is used by socket filtering, seccomp and soon by tracing and
exposed to userspace, therefore 'sock_filter_int' name is not accurate.
Rename it to 'bpf_insn'
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Create a module that allows udelay() to be executed to ensure that
it is delaying at least as long as requested (with a little bit of
error allowed).
There are some configurations which don't have reliably udelay
due to using a loop delay with cpufreq changes which should use
a counter time based delay instead. This test aims to identify
those configurations where timing is unreliable.
Signed-off-by: David Riley <davidriley@chromium.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
David Howells