Patch series "lib: rework bitmap_parselist and tests", v5.
bitmap_parselist has been evolved from a pretty simple idea for long and
now lacks for refactoring. It is not structured, has nested loops and a
set of opaque-named variables.
Things are more complicated because bitmap_parselist() is a part of user
interface, and its behavior should not change.
In this patchset
- bitmap_parselist_user() made a wrapper on bitmap_parselist();
- bitmap_parselist() reworked (patch 2);
- time measurement in test_bitmap_parselist switched to ktime_get
(patch 3);
- new tests introduced (patch 4), and
- bitmap_parselist_user() testing enabled with the same testset as
bitmap_parselist() (patch 5).
This patch (of 5):
Currently we parse user data byte after byte which leads to
overcomplification of parsing algorithm. The only user of
bitmap_parselist_user() is not performance-critical, and so we can
duplicate user data to kernel buffer and simply call bitmap_parselist().
This rework lets us unify and simplify bitmap_parselist() and
bitmap_parselist_user(), which is done in the following patch.
Link: http://lkml.kernel.org/r/20190405173211.11373-2-ynorov@marvell.com
Signed-off-by: Yury Norov <ynorov@marvell.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Mike Travis <travis@sgi.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The integer exponentiation is used in few places and might be used in
the future by other call sites. Move it to wider use.
Link: http://lkml.kernel.org/r/20190323172531.80025-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For better maintenance and expansion move the mathematic helpers to the
separate folder.
No functional change intended.
Note, the int_sqrt() is not used as a part of lib, so, moved to regular
obj.
Link: http://lkml.kernel.org/r/20190323172531.80025-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Ray Jui <rjui@broadcom.com>
[mchehab+samsung@kernel.org: fix broken doc references for div64.c and gcd.c]
Link: http://lkml.kernel.org/r/734f49bae5d4052b3c25691dfefad59bea2e5843.1555580999.git.mchehab+samsung@kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_RETPOLINE has severely degraded indirect function call
performance, so it's worth putting some effort into reducing the number
of times cmp() is called.
This patch avoids badly unbalanced merges on unlucky input sizes. It
slightly increases the code size, but saves an average of 0.2*n calls to
cmp().
x86-64 code size 739 -> 803 bytes (+64)
Unfortunately, there's not a lot of low-hanging fruit in a merge sort;
it already performs only n*log2(n) - K*n + O(1) compares. The leading
coefficient is already at the theoretical limit (log2(n!) corresponds to
K=1.4427), so we're fighting over the linear term, and the best
mergesort can do is K=1.2645, achieved when n is a power of 2.
The differences between mergesort variants appear when n is *not* a
power of 2; K is a function of the fractional part of log2(n). Top-down
mergesort does best of all, achieving a minimum K=1.2408, and an average
(over all sizes) K=1.248. However, that requires knowing the number of
entries to be sorted ahead of time, and making a full pass over the
input to count it conflicts with a second performance goal, which is
cache blocking.
Obviously, we have to read the entire list into L1 cache at some point,
and performance is best if it fits. But if it doesn't fit, each full
pass over the input causes a cache miss per element, which is
undesirable.
While textbooks explain bottom-up mergesort as a succession of merging
passes, practical implementations do merging in depth-first order: as
soon as two lists of the same size are available, they are merged. This
allows as many merge passes as possible to fit into L1; only the final
few merges force cache misses.
This cache-friendly depth-first merge order depends on us merging the
beginning of the input as much as possible before we've even seen the
end of the input (and thus know its size).
The simple eager merge pattern causes bad performance when n is just
over a power of 2. If n=1028, the final merge is between 1024- and
4-element lists, which is wasteful of comparisons. (This is actually
worse on average than n=1025, because a 1204:1 merge will, on average,
end after 512 compares, while 1024:4 will walk 4/5 of the list.)
Because of this, bottom-up mergesort achieves K < 0.5 for such sizes,
and has an average (over all sizes) K of around 1. (My experiments show
K=1.01, while theory predicts K=0.965.)
There are "worst-case optimal" variants of bottom-up mergesort which
avoid this bad performance, but the algorithms given in the literature,
such as queue-mergesort and boustrodephonic mergesort, depend on the
breadth-first multi-pass structure that we are trying to avoid.
This implementation is as eager as possible while ensuring that all
merge passes are at worst 1:2 unbalanced. This achieves the same
average K=1.207 as queue-mergesort, which is 0.2*n better then
bottom-up, and only 0.04*n behind top-down mergesort.
Specifically, defers merging two lists of size 2^k until it is known
that there are 2^k additional inputs following. This ensures that the
final uneven merges triggered by reaching the end of the input will be
at worst 2:1. This will avoid cache misses as long as 3*2^k elements
fit into the cache.
(I confess to being more than a little bit proud of how clean this code
turned out. It took a lot of thinking, but the resultant inner loop is
very simple and efficient.)
Refs:
Bottom-up Mergesort: A Detailed Analysis
Wolfgang Panny, Helmut Prodinger
Algorithmica 14(4):340--354, October 1995
https://doi.org/10.1007/BF01294131https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.6.5260
The cost distribution of queue-mergesort, optimal mergesorts, and
power-of-two rules
Wei-Mei Chen, Hsien-Kuei Hwang, Gen-Huey Chen
Journal of Algorithms 30(2); Pages 423--448, February 1999
https://doi.org/10.1006/jagm.1998.0986https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.4.5380
Queue-Mergesort
Mordecai J. Golin, Robert Sedgewick
Information Processing Letters, 48(5):253--259, 10 December 1993
https://doi.org/10.1016/0020-0190(93)90088-qhttps://sci-hub.tw/10.1016/0020-0190(93)90088-Q
Feedback from Rasmus Villemoes <linux@rasmusvillemoes.dk>.
Link: http://lkml.kernel.org/r/fd560853cc4dca0d0f02184ffa888b4c1be89abc.1552704200.git.lkml@sdf.org
Signed-off-by: George Spelvin <lkml@sdf.org>
Acked-by: Andrey Abramov <st5pub@yandex.ru>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Daniel Wagner <daniel.wagner@siemens.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Don Mullis <don.mullis@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rather than a fixed-size array of pending sorted runs, use the ->prev
links to keep track of things. This reduces stack usage, eliminates
some ugly overflow handling, and reduces the code size.
Also:
* merge() no longer needs to handle NULL inputs, so simplify.
* The same applies to merge_and_restore_back_links(), which is renamed
to the less ponderous merge_final(). (It's a static helper function,
so we don't need a super-descriptive name; comments will do.)
* Document the actual return value requirements on the (*cmp)()
function; some callers are already using this feature.
x86-64 code size 1086 -> 739 bytes (-347)
(Yes, I see checkpatch complaining about no space after comma in
"__attribute__((nonnull(2,3,4,5)))". Checkpatch is wrong.)
Feedback from Rasmus Villemoes, Andy Shevchenko and Geert Uytterhoeven.
[akpm@linux-foundation.org: remove __pure usage due to mysterious warning]
Link: http://lkml.kernel.org/r/f63c410e0ff76009c9b58e01027e751ff7fdb749.1552704200.git.lkml@sdf.org
Signed-off-by: George Spelvin <lkml@sdf.org>
Acked-by: Andrey Abramov <st5pub@yandex.ru>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Daniel Wagner <daniel.wagner@siemens.com>
Cc: Dave Chinner <dchinner@redhat.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>
Similar to what's being done in the net code, this takes advantage of
the fact that most invocations use only a few common swap functions, and
replaces indirect calls to them with (highly predictable) conditional
branches. (The downside, of course, is that if you *do* use a custom
swap function, there are a few extra predicted branches on the code
path.)
This actually *shrinks* the x86-64 code, because it inlines the various
swap functions inside do_swap, eliding function prologues & epilogues.
x86-64 code size 767 -> 703 bytes (-64)
Link: http://lkml.kernel.org/r/d10c5d4b393a1847f32f5b26f4bbaa2857140e1e.1552704200.git.lkml@sdf.org
Signed-off-by: George Spelvin <lkml@sdf.org>
Acked-by: Andrey Abramov <st5pub@yandex.ru>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Daniel Wagner <daniel.wagner@siemens.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Don Mullis <don.mullis@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This uses fewer comparisons than the previous code (approaching half as
many for large random inputs), but produces identical results; it
actually performs the exact same series of swap operations.
Specifically, it reduces the average number of compares from
2*n*log2(n) - 3*n + o(n)
to
n*log2(n) + 0.37*n + o(n).
This is still 1.63*n worse than glibc qsort() which manages n*log2(n) -
1.26*n, but at least the leading coefficient is correct.
Standard heapsort, when sifting down, performs two comparisons per
level: one to find the greater child, and a second to see if the current
node should be exchanged with that child.
Bottom-up heapsort observes that it's better to postpone the second
comparison and search for the leaf where -infinity would be sent to,
then search back *up* for the current node's destination.
Since sifting down usually proceeds to the leaf level (that's where half
the nodes are), this does O(1) second comparisons rather than log2(n).
That saves a lot of (expensive since Spectre) indirect function calls.
The one time it's worse than the previous code is if there are large
numbers of duplicate keys, when the top-down algorithm is O(n) and
bottom-up is O(n log n). For distinct keys, it's provably always
better, doing 1.5*n*log2(n) + O(n) in the worst case.
(The code is not significantly more complex. This patch also merges the
heap-building and -extracting sift-down loops, resulting in a net code
size savings.)
x86-64 code size 885 -> 767 bytes (-118)
(I see the checkpatch complaint about "else if (n -= size)". The
alternative is significantly uglier.)
Link: http://lkml.kernel.org/r/2de8348635a1a421a72620677898c7fd5bd4b19d.1552704200.git.lkml@sdf.org
Signed-off-by: George Spelvin <lkml@sdf.org>
Acked-by: Andrey Abramov <st5pub@yandex.ru>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Daniel Wagner <daniel.wagner@siemens.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Don Mullis <don.mullis@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "lib/sort & lib/list_sort: faster and smaller", v2.
Because CONFIG_RETPOLINE has made indirect calls much more expensive, I
thought I'd try to reduce the number made by the library sort functions.
The first three patches apply to lib/sort.c.
Patch #1 is a simple optimization. The built-in swap has special cases
for aligned 4- and 8-byte objects. But those are almost never used;
most calls to sort() work on larger structures, which fall back to the
byte-at-a-time loop. This generalizes them to aligned *multiples* of 4
and 8 bytes. (If nothing else, it saves an awful lot of energy by not
thrashing the store buffers as much.)
Patch #2 grabs a juicy piece of low-hanging fruit. I agree that nice
simple solid heapsort is preferable to more complex algorithms (sorry,
Andrey), but it's possible to implement heapsort with far fewer
comparisons (50% asymptotically, 25-40% reduction for realistic sizes)
than the way it's been done up to now. And with some care, the code
ends up smaller, as well. This is the "big win" patch.
Patch #3 adds the same sort of indirect call bypass that has been added
to the net code of late. The great majority of the callers use the
builtin swap functions, so replace the indirect call to sort_func with a
(highly preditable) series of if() statements. Rather surprisingly,
this decreased code size, as the swap functions were inlined and their
prologue & epilogue code eliminated.
lib/list_sort.c is a bit trickier, as merge sort is already close to
optimal, and we don't want to introduce triumphs of theory over
practicality like the Ford-Johnson merge-insertion sort.
Patch #4, without changing the algorithm, chops 32% off the code size
and removes the part[MAX_LIST_LENGTH+1] pointer array (and the
corresponding upper limit on efficiently sortable input size).
Patch #5 improves the algorithm. The previous code is already optimal
for power-of-two (or slightly smaller) size inputs, but when the input
size is just over a power of 2, there's a very unbalanced final merge.
There are, in the literature, several algorithms which solve this, but
they all depend on the "breadth-first" merge order which was replaced by
commit 835cc0c847 with a more cache-friendly "depth-first" order.
Some hard thinking came up with a depth-first algorithm which defers
merges as little as possible while avoiding bad merges. This saves
0.2*n compares, averaged over all sizes.
The code size increase is minimal (64 bytes on x86-64, reducing the net
savings to 26%), but the comments expanded significantly to document the
clever algorithm.
TESTING NOTES: I have some ugly user-space benchmarking code which I
used for testing before moving this code into the kernel. Shout if you
want a copy.
I'm running this code right now, with CONFIG_TEST_SORT and
CONFIG_TEST_LIST_SORT, but I confess I haven't rebooted since the last
round of minor edits to quell checkpatch. I figure there will be at
least one round of comments and final testing.
This patch (of 5):
Rather than having special-case swap functions for 4- and 8-byte
objects, special-case aligned multiples of 4 or 8 bytes. This speeds up
most users of sort() by avoiding fallback to the byte copy loop.
Despite what ca96ab859a ("lib/sort: Add 64 bit swap function") claims,
very few users of sort() sort pointers (or pointer-sized objects); most
sort structures containing at least two words. (E.g.
drivers/acpi/fan.c:acpi_fan_get_fps() sorts an array of 40-byte struct
acpi_fan_fps.)
The functions also got renamed to reflect the fact that they support
multiple words. In the great tradition of bikeshedding, the names were
by far the most contentious issue during review of this patch series.
x86-64 code size 872 -> 886 bytes (+14)
With feedback from Andy Shevchenko, Rasmus Villemoes and Geert
Uytterhoeven.
Link: http://lkml.kernel.org/r/f24f932df3a7fa1973c1084154f1cea596bcf341.1552704200.git.lkml@sdf.org
Signed-off-by: George Spelvin <lkml@sdf.org>
Acked-by: Andrey Abramov <st5pub@yandex.ru>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Daniel Wagner <daniel.wagner@siemens.com>
Cc: Don Mullis <don.mullis@gmail.com>
Cc: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a lot more appropriate than PI_LIST, which in the kernel one
would assume that it has to do with priority-inheritance; which is not
-- furthermore futexes make use of plists so this can be even more
confusing, albeit the debug nature of the config option.
Link: http://lkml.kernel.org/r/20190317185434.1626-1-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The bitmap_remap, _bitremap, _onto and _fold functions are only used,
via their node_ wrappers, in mm/mempolicy.c, which is only built for
CONFIG_NUMA. The helper bitmap_ord_to_pos used by these functions is
global, but its only external caller is node_random() in lib/nodemask.c,
which is also guarded by CONFIG_NUMA.
For !CONFIG_NUMA:
add/remove: 0/6 grow/shrink: 0/0 up/down: 0/-621 (-621)
Function old new delta
bitmap_pos_to_ord 20 - -20
bitmap_ord_to_pos 70 - -70
bitmap_bitremap 81 - -81
bitmap_fold 113 - -113
bitmap_onto 123 - -123
bitmap_remap 214 - -214
Total: Before=4776, After=4155, chg -13.00%
Link: http://lkml.kernel.org/r/20190329205353.6010-2-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
AFAICT, there have never been any callers of these functions outside
mm/mempolicy.c (via their nodemask.h wrappers). In particular, no
modular code has ever used them, and given their somewhat exotic
semantics, I highly doubt they will ever find such a use. In any case,
no need to export them currently.
Link: http://lkml.kernel.org/r/20190329205353.6010-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 60a3cdd063 ("x86: add optimized inlining") introduced
CONFIG_OPTIMIZE_INLINING, but it has been available only for x86.
The idea is obviously arch-agnostic. This commit moves the config entry
from arch/x86/Kconfig.debug to lib/Kconfig.debug so that all
architectures can benefit from it.
This can make a huge difference in kernel image size especially when
CONFIG_OPTIMIZE_FOR_SIZE is enabled.
For example, I got 3.5% smaller arm64 kernel for v5.1-rc1.
dec file
18983424 arch/arm64/boot/Image.before
18321920 arch/arm64/boot/Image.after
This also slightly improves the "Kernel hacking" Kconfig menu as
e61aca5158 ("Merge branch 'kconfig-diet' from Dave Hansen') suggested;
this config option would be a good fit in the "compiler option" menu.
Link: http://lkml.kernel.org/r/20190423034959.13525-12-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To facilitate additional options to get_user_pages_fast() change the
singular write parameter to be gup_flags.
This patch does not change any functionality. New functionality will
follow in subsequent patches.
Some of the get_user_pages_fast() call sites were unchanged because they
already passed FOLL_WRITE or 0 for the write parameter.
NOTE: It was suggested to change the ordering of the get_user_pages_fast()
arguments to ensure that callers were converted. This breaks the current
GUP call site convention of having the returned pages be the final
parameter. So the suggestion was rejected.
Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Mike Marshall <hubcap@omnibond.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove an unnecessary arch complication:
arch/x86/include/asm/arch_hweight.h uses __sw_hweight{32,64} as
alternatives, and they are implemented in arch/x86/lib/hweight.S
x86 does not rely on the generic C implementation lib/hweight.c
at all, so CONFIG_GENERIC_HWEIGHT should be disabled.
__HAVE_ARCH_SW_HWEIGHT is not necessary either.
No change in functionality intended.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uros Bizjak <ubizjak@gmail.com>
Link: http://lkml.kernel.org/r/1557665521-17570-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=lg6O
-----END PGP SIGNATURE-----
Merge tag 'printk-for-5.2-fixes' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk fixup from Petr Mladek:
"Replace the problematic probe_kernel_read() with original simple
pointer checks in vsprintf()"
* tag 'printk-for-5.2-fixes' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
vsprintf: Do not break early boot with probing addresses
The commit 3e5903eb9c ("vsprintf: Prevent crash when dereferencing
invalid pointers") broke boot on several architectures. The common
pattern is that probe_kernel_read() is not working during early
boot because userspace access framework is not ready.
It is a generic problem. We have to avoid any complex external
functions in vsprintf() code, especially in the common path.
They might break printk() easily and are hard to debug.
Replace probe_kernel_read() with some simple checks for obvious
problems.
Details:
1. Report on Power:
Kernel crashes very early during boot with with CONFIG_PPC_KUAP and
CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG
The problem is the combination of some new code called via printk(),
check_pointer() which calls probe_kernel_read(). That then calls
allow_user_access() (PPC_KUAP) and that uses mmu_has_feature() too early
(before we've patched features). With the JUMP_LABEL debug enabled that
causes us to call printk() & dump_stack() and we end up recursing and
overflowing the stack.
Because it happens so early you don't get any output, just an apparently
dead system.
The stack trace (which you don't see) is something like:
...
dump_stack+0xdc
probe_kernel_read+0x1a4
check_pointer+0x58
string+0x3c
vsnprintf+0x1bc
vscnprintf+0x20
printk_safe_log_store+0x7c
printk+0x40
dump_stack_print_info+0xbc
dump_stack+0x8
probe_kernel_read+0x1a4
probe_kernel_read+0x19c
check_pointer+0x58
string+0x3c
vsnprintf+0x1bc
vscnprintf+0x20
vprintk_store+0x6c
vprintk_emit+0xec
vprintk_func+0xd4
printk+0x40
cpufeatures_process_feature+0xc8
scan_cpufeatures_subnodes+0x380
of_scan_flat_dt_subnodes+0xb4
dt_cpu_ftrs_scan_callback+0x158
of_scan_flat_dt+0xf0
dt_cpu_ftrs_scan+0x3c
early_init_devtree+0x360
early_setup+0x9c
2. Report on s390:
vsnprintf invocations, are broken on s390. For example, the early boot
output now looks like this where the first (efault) should be
the linux_banner:
[ 0.099985] (efault)
[ 0.099985] setup: Linux is running as a z/VM guest operating system in 64-bit mode
[ 0.100066] setup: The maximum memory size is 8192MB
[ 0.100070] cma: Reserved 4 MiB at (efault)
[ 0.100100] numa: NUMA mode: (efault)
The reason for this, is that the code assumes that
probe_kernel_address() works very early. This however is not true on
at least s390. Uaccess on KERNEL_DS works only after page tables have
been setup on s390, which happens with setup_arch()->paging_init().
Any probe_kernel_address() invocation before that will return -EFAULT.
Fixes: 3e5903eb9c ("vsprintf: Prevent crash when dereferencing invalid pointers")
Link: http://lkml.kernel.org/r/20190510084213.22149-1-pmladek@suse.com
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Russell Currey <ruscur@russell.cc>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Stephen Rothwell <sfr@ozlabs.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
This has been a smaller cycle than normal. One new driver was accepted,
which is unusual, and at least one more driver remains in review on the
list.
- Driver fixes for hns, hfi1, nes, rxe, i40iw, mlx5, cxgb4, vmw_pvrdma
- Many patches from MatthewW converting radix tree and IDR users to use
xarray
- Introduction of tracepoints to the MAD layer
- Build large SGLs at the start for DMA mapping and get the driver to
split them
- Generally clean SGL handling code throughout the subsystem
- Support for restricting RDMA devices to net namespaces for containers
- Progress to remove object allocation boilerplate code from drivers
- Change in how the mlx5 driver shows representor ports linked to VFs
- mlx5 uapi feature to access the on chip SW ICM memory
- Add a new driver for 'EFA'. This is HW that supports user space packet
processing through QPs in Amazon's cloud
-----BEGIN PGP SIGNATURE-----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=TS64
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull rdma updates from Jason Gunthorpe:
"This has been a smaller cycle than normal. One new driver was
accepted, which is unusual, and at least one more driver remains in
review on the list.
Summary:
- Driver fixes for hns, hfi1, nes, rxe, i40iw, mlx5, cxgb4,
vmw_pvrdma
- Many patches from MatthewW converting radix tree and IDR users to
use xarray
- Introduction of tracepoints to the MAD layer
- Build large SGLs at the start for DMA mapping and get the driver to
split them
- Generally clean SGL handling code throughout the subsystem
- Support for restricting RDMA devices to net namespaces for
containers
- Progress to remove object allocation boilerplate code from drivers
- Change in how the mlx5 driver shows representor ports linked to VFs
- mlx5 uapi feature to access the on chip SW ICM memory
- Add a new driver for 'EFA'. This is HW that supports user space
packet processing through QPs in Amazon's cloud"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (186 commits)
RDMA/ipoib: Allow user space differentiate between valid dev_port
IB/core, ipoib: Do not overreact to SM LID change event
RDMA/device: Don't fire uevent before device is fully initialized
lib/scatterlist: Remove leftover from sg_page_iter comment
RDMA/efa: Add driver to Kconfig/Makefile
RDMA/efa: Add the efa module
RDMA/efa: Add EFA verbs implementation
RDMA/efa: Add common command handlers
RDMA/efa: Implement functions that submit and complete admin commands
RDMA/efa: Add the ABI definitions
RDMA/efa: Add the com service API definitions
RDMA/efa: Add the efa_com.h file
RDMA/efa: Add the efa.h header file
RDMA/efa: Add EFA device definitions
RDMA: Add EFA related definitions
RDMA/umem: Remove hugetlb flag
RDMA/bnxt_re: Use core helpers to get aligned DMA address
RDMA/i40iw: Use core helpers to get aligned DMA address within a supported page size
RDMA/verbs: Add a DMA iterator to return aligned contiguous memory blocks
RDMA/umem: Add API to find best driver supported page size in an MR
...
Pull networking updates from David Miller:
"Highlights:
1) Support AES128-CCM ciphers in kTLS, from Vakul Garg.
2) Add fib_sync_mem to control the amount of dirty memory we allow to
queue up between synchronize RCU calls, from David Ahern.
3) Make flow classifier more lockless, from Vlad Buslov.
4) Add PHY downshift support to aquantia driver, from Heiner
Kallweit.
5) Add SKB cache for TCP rx and tx, from Eric Dumazet. This reduces
contention on SLAB spinlocks in heavy RPC workloads.
6) Partial GSO offload support in XFRM, from Boris Pismenny.
7) Add fast link down support to ethtool, from Heiner Kallweit.
8) Use siphash for IP ID generator, from Eric Dumazet.
9) Pull nexthops even further out from ipv4/ipv6 routes and FIB
entries, from David Ahern.
10) Move skb->xmit_more into a per-cpu variable, from Florian
Westphal.
11) Improve eBPF verifier speed and increase maximum program size,
from Alexei Starovoitov.
12) Eliminate per-bucket spinlocks in rhashtable, and instead use bit
spinlocks. From Neil Brown.
13) Allow tunneling with GUE encap in ipvs, from Jacky Hu.
14) Improve link partner cap detection in generic PHY code, from
Heiner Kallweit.
15) Add layer 2 encap support to bpf_skb_adjust_room(), from Alan
Maguire.
16) Remove SKB list implementation assumptions in SCTP, your's truly.
17) Various cleanups, optimizations, and simplifications in r8169
driver. From Heiner Kallweit.
18) Add memory accounting on TX and RX path of SCTP, from Xin Long.
19) Switch PHY drivers over to use dynamic featue detection, from
Heiner Kallweit.
20) Support flow steering without masking in dpaa2-eth, from Ioana
Ciocoi.
21) Implement ndo_get_devlink_port in netdevsim driver, from Jiri
Pirko.
22) Increase the strict parsing of current and future netlink
attributes, also export such policies to userspace. From Johannes
Berg.
23) Allow DSA tag drivers to be modular, from Andrew Lunn.
24) Remove legacy DSA probing support, also from Andrew Lunn.
25) Allow ll_temac driver to be used on non-x86 platforms, from Esben
Haabendal.
26) Add a generic tracepoint for TX queue timeouts to ease debugging,
from Cong Wang.
27) More indirect call optimizations, from Paolo Abeni"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1763 commits)
cxgb4: Fix error path in cxgb4_init_module
net: phy: improve pause mode reporting in phy_print_status
dt-bindings: net: Fix a typo in the phy-mode list for ethernet bindings
net: macb: Change interrupt and napi enable order in open
net: ll_temac: Improve error message on error IRQ
net/sched: remove block pointer from common offload structure
net: ethernet: support of_get_mac_address new ERR_PTR error
net: usb: smsc: fix warning reported by kbuild test robot
staging: octeon-ethernet: Fix of_get_mac_address ERR_PTR check
net: dsa: support of_get_mac_address new ERR_PTR error
net: dsa: sja1105: Fix status initialization in sja1105_get_ethtool_stats
vrf: sit mtu should not be updated when vrf netdev is the link
net: dsa: Fix error cleanup path in dsa_init_module
l2tp: Fix possible NULL pointer dereference
taprio: add null check on sched_nest to avoid potential null pointer dereference
net: mvpp2: cls: fix less than zero check on a u32 variable
net_sched: sch_fq: handle non connected flows
net_sched: sch_fq: do not assume EDT packets are ordered
net: hns3: use devm_kcalloc when allocating desc_cb
net: hns3: some cleanup for struct hns3_enet_ring
...
-----BEGIN PGP SIGNATURE-----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=Ot0g
-----END PGP SIGNATURE-----
Merge tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
"Nothing major in this series, just fixes and improvements all over the
map. This contains:
- Series of fixes for sed-opal (David, Jonas)
- Fixes and performance tweaks for BFQ (via Paolo)
- Set of fixes for bcache (via Coly)
- Set of fixes for md (via Song)
- Enabling multi-page for passthrough requests (Ming)
- Queue release fix series (Ming)
- Device notification improvements (Martin)
- Propagate underlying device rotational status in loop (Holger)
- Removal of mtip32xx trim support, which has been disabled for years
(Christoph)
- Improvement and cleanup of nvme command handling (Christoph)
- Add block SPDX tags (Christoph)
- Cleanup/hardening of bio/bvec iteration (Christoph)
- A few NVMe pull requests (Christoph)
- Removal of CONFIG_LBDAF (Christoph)
- Various little fixes here and there"
* tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-block: (164 commits)
block: fix mismerge in bvec_advance
block: don't drain in-progress dispatch in blk_cleanup_queue()
blk-mq: move cancel of hctx->run_work into blk_mq_hw_sysfs_release
blk-mq: always free hctx after request queue is freed
blk-mq: split blk_mq_alloc_and_init_hctx into two parts
blk-mq: free hw queue's resource in hctx's release handler
blk-mq: move cancel of requeue_work into blk_mq_release
blk-mq: grab .q_usage_counter when queuing request from plug code path
block: fix function name in comment
nvmet: protect discovery change log event list iteration
nvme: mark nvme_core_init and nvme_core_exit static
nvme: move command size checks to the core
nvme-fabrics: check more command sizes
nvme-pci: check more command sizes
nvme-pci: remove an unneeded variable initialization
nvme-pci: unquiesce admin queue on shutdown
nvme-pci: shutdown on timeout during deletion
nvme-pci: fix psdt field for single segment sgls
nvme-multipath: don't print ANA group state by default
nvme-multipath: split bios with the ns_head bio_set before submitting
...
Here is the "real" big set of char/misc driver patches for 5.2-rc1
Loads of different driver subsystem stuff in here, all over the places:
- thunderbolt driver updates
- habanalabs driver updates
- nvmem driver updates
- extcon driver updates
- intel_th driver updates
- mei driver updates
- coresight driver updates
- soundwire driver cleanups and updates
- fastrpc driver updates
- other minor driver updates
- chardev minor fixups
Feels like this tree is getting to be a dumping ground of "small driver
subsystems" these days. Which is fine with me, if it makes things
easier for those subsystem maintainers.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iGwEABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXNHE2w8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ykvyQCYj5vSHQ88yEU+bzwGzQQLOBWYIwCgm5Iku0Y3
f6V3MvRffg4qUp3cGbU=
=R37j
-----END PGP SIGNATURE-----
Merge tag 'char-misc-5.2-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc update part 2 from Greg KH:
"Here is the "real" big set of char/misc driver patches for 5.2-rc1
Loads of different driver subsystem stuff in here, all over the places:
- thunderbolt driver updates
- habanalabs driver updates
- nvmem driver updates
- extcon driver updates
- intel_th driver updates
- mei driver updates
- coresight driver updates
- soundwire driver cleanups and updates
- fastrpc driver updates
- other minor driver updates
- chardev minor fixups
Feels like this tree is getting to be a dumping ground of "small
driver subsystems" these days. Which is fine with me, if it makes
things easier for those subsystem maintainers.
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-5.2-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (255 commits)
intel_th: msu: Add current window tracking
intel_th: msu: Add a sysfs attribute to trigger window switch
intel_th: msu: Correct the block wrap detection
intel_th: Add switch triggering support
intel_th: gth: Factor out trace start/stop
intel_th: msu: Factor out pipeline draining
intel_th: msu: Switch over to scatterlist
intel_th: msu: Replace open-coded list_{first,last,next}_entry variants
intel_th: Only report useful IRQs to subdevices
intel_th: msu: Start handling IRQs
intel_th: pci: Use MSI interrupt signalling
intel_th: Communicate IRQ via resource
intel_th: Add "rtit" source device
intel_th: Skip subdevices if their MMIO is missing
intel_th: Rework resource passing between glue layers and core
intel_th: SPDX-ify the documentation
intel_th: msu: Fix single mode with IOMMU
coresight: funnel: Support static funnel
dt-bindings: arm: coresight: Unify funnel DT binding
coresight: replicator: Add new device id for static replicator
...
Here is the "big" set of driver core patches for 5.2-rc1
There are a number of ACPI patches in here as well, as Rafael said they
should go through this tree due to the driver core changes they
required. They have all been acked by the ACPI developers.
There are also a number of small subsystem-specific changes in here, due
to some changes to the kobject core code. Those too have all been acked
by the various subsystem maintainers.
As for content, it's pretty boring outside of the ACPI changes:
- spdx cleanups
- kobject documentation updates
- default attribute groups for kobjects
- other minor kobject/driver core fixes
All have been in linux-next for a while with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXNHDbw8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ynDAgCfbb4LBR6I50wFXb8JM/R6cAS7qrsAn1unshKV
8XCYcif2RxjtdJWXbjdm
=/rLh
-----END PGP SIGNATURE-----
Merge tag 'driver-core-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core/kobject updates from Greg KH:
"Here is the "big" set of driver core patches for 5.2-rc1
There are a number of ACPI patches in here as well, as Rafael said
they should go through this tree due to the driver core changes they
required. They have all been acked by the ACPI developers.
There are also a number of small subsystem-specific changes in here,
due to some changes to the kobject core code. Those too have all been
acked by the various subsystem maintainers.
As for content, it's pretty boring outside of the ACPI changes:
- spdx cleanups
- kobject documentation updates
- default attribute groups for kobjects
- other minor kobject/driver core fixes
All have been in linux-next for a while with no reported issues"
* tag 'driver-core-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (47 commits)
kobject: clean up the kobject add documentation a bit more
kobject: Fix kernel-doc comment first line
kobject: Remove docstring reference to kset
firmware_loader: Fix a typo ("syfs" -> "sysfs")
kobject: fix dereference before null check on kobj
Revert "driver core: platform: Fix the usage of platform device name(pdev->name)"
init/config: Do not select BUILD_BIN2C for IKCONFIG
Provide in-kernel headers to make extending kernel easier
kobject: Improve doc clarity kobject_init_and_add()
kobject: Improve docs for kobject_add/del
driver core: platform: Fix the usage of platform device name(pdev->name)
livepatch: Replace klp_ktype_patch's default_attrs with groups
cpufreq: schedutil: Replace default_attrs field with groups
padata: Replace padata_attr_type default_attrs field with groups
irqdesc: Replace irq_kobj_type's default_attrs field with groups
net-sysfs: Replace ktype default_attrs field with groups
block: Replace all ktype default_attrs with groups
samples/kobject: Replace foo_ktype's default_attrs field with groups
kobject: Add support for default attribute groups to kobj_type
driver core: Postpone DMA tear-down until after devres release for probe failure
...
Hi Linus,
This is my very first pull-request. I've been working full-time as
a kernel developer for more than two years now. During this time I've
been fixing bugs reported by Coverity all over the tree and, as part
of my work, I'm also contributing to the KSPP. My work in the kernel
community has been supervised by Greg KH and Kees Cook.
OK. So, after the quick introduction above, please, pull the following
patches that mark switch cases where we are expecting to fall through.
These patches are part of the ongoing efforts to enable -Wimplicit-fallthrough.
They have been ignored for a long time (most of them more than 3 months,
even after pinging multiple times), which is the reason why I've created
this tree. Most of them have been baking in linux-next for a whole development
cycle. And with Stephen Rothwell's help, we've had linux-next nag-emails
going out for newly introduced code that triggers -Wimplicit-fallthrough
to avoid gaining more of these cases while we work to remove the ones
that are already present.
I'm happy to let you know that we are getting close to completing this
work. Currently, there are only 32 of 2311 of these cases left to be
addressed in linux-next. I'm auditing every case; I take a look into
the code and analyze it in order to determine if I'm dealing with an
actual bug or a false positive, as explained here:
https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/
While working on this, I've found and fixed the following missing
break/return bugs, some of them introduced more than 5 years ago:
84242b82d87850b51b6c5e420fe63509186e5034b5be8531817264235ee7cc5034a5d2479826cc865340f23df8df997abeeb2f10d82373307b00c5e65d25ff7a54a7ed5b3e7dc24bfa8f21ad0eaee6199ba8376ce1dc586a60a1a8e9b186f14e57562b4860747828eac5b974bee9cc44ba91162c930e3d0a
Once this work is finish, we'll be able to universally enable
"-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
entering the kernel again.
Thanks
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
-----BEGIN PGP SIGNATURE-----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=k30z
-----END PGP SIGNATURE-----
Merge tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux
Pull Wimplicit-fallthrough updates from Gustavo A. R. Silva:
"Mark switch cases where we are expecting to fall through.
This is part of the ongoing efforts to enable -Wimplicit-fallthrough.
Most of them have been baking in linux-next for a whole development
cycle. And with Stephen Rothwell's help, we've had linux-next
nag-emails going out for newly introduced code that triggers
-Wimplicit-fallthrough to avoid gaining more of these cases while we
work to remove the ones that are already present.
We are getting close to completing this work. Currently, there are
only 32 of 2311 of these cases left to be addressed in linux-next. I'm
auditing every case; I take a look into the code and analyze it in
order to determine if I'm dealing with an actual bug or a false
positive, as explained here:
https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/
While working on this, I've found and fixed the several missing
break/return bugs, some of them introduced more than 5 years ago.
Once this work is finished, we'll be able to universally enable
"-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
entering the kernel again"
* tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (27 commits)
memstick: mark expected switch fall-throughs
drm/nouveau/nvkm: mark expected switch fall-throughs
NFC: st21nfca: Fix fall-through warnings
NFC: pn533: mark expected switch fall-throughs
block: Mark expected switch fall-throughs
ASN.1: mark expected switch fall-through
lib/cmdline.c: mark expected switch fall-throughs
lib: zstd: Mark expected switch fall-throughs
scsi: sym53c8xx_2: sym_nvram: Mark expected switch fall-through
scsi: sym53c8xx_2: sym_hipd: mark expected switch fall-throughs
scsi: ppa: mark expected switch fall-through
scsi: osst: mark expected switch fall-throughs
scsi: lpfc: lpfc_scsi: Mark expected switch fall-throughs
scsi: lpfc: lpfc_nvme: Mark expected switch fall-through
scsi: lpfc: lpfc_nportdisc: Mark expected switch fall-through
scsi: lpfc: lpfc_hbadisc: Mark expected switch fall-throughs
scsi: lpfc: lpfc_els: Mark expected switch fall-throughs
scsi: lpfc: lpfc_ct: Mark expected switch fall-throughs
scsi: imm: mark expected switch fall-throughs
scsi: csiostor: csio_wr: mark expected switch fall-through
...
-----BEGIN PGP SIGNATURE-----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=WZfC
-----END PGP SIGNATURE-----
Merge tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk updates from Petr Mladek:
- Allow state reset of printk_once() calls.
- Prevent crashes when dereferencing invalid pointers in vsprintf().
Only the first byte is checked for simplicity.
- Make vsprintf warnings consistent and inlined.
- Treewide conversion of obsolete %pf, %pF to %ps, %pF printf
modifiers.
- Some clean up of vsprintf and test_printf code.
* tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
lib/vsprintf: Make function pointer_string static
vsprintf: Limit the length of inlined error messages
vsprintf: Avoid confusion between invalid address and value
vsprintf: Prevent crash when dereferencing invalid pointers
vsprintf: Consolidate handling of unknown pointer specifiers
vsprintf: Factor out %pO handler as kobject_string()
vsprintf: Factor out %pV handler as va_format()
vsprintf: Factor out %p[iI] handler as ip_addr_string()
vsprintf: Do not check address of well-known strings
vsprintf: Consistent %pK handling for kptr_restrict == 0
vsprintf: Shuffle restricted_pointer()
printk: Tie printk_once / printk_deferred_once into .data.once for reset
treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
lib/test_printf: Switch to bitmap_zalloc()
This Kselftest update for Linux 5.2-rc1 consists of
- fixes to seccomp test, and kselftest framework
- cleanups to remove duplicate header defines
- fixes to efivarfs "make clean" target
- cgroup cleanup path
- Moving the IMA kexec_load selftest to selftests/kexec work from
Mimi Johar and Petr Vorel
- A framework to kselftest for writing kernel test modules addition
from Tobin C. Harding
-----BEGIN PGP SIGNATURE-----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=pNRO
-----END PGP SIGNATURE-----
Merge tag 'linux-kselftest-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull Kselftest updates from Shuah Khan:
- fixes to seccomp test, and kselftest framework
- cleanups to remove duplicate header defines
- fixes to efivarfs "make clean" target
- cgroup cleanup path
- Moving the IMA kexec_load selftest to selftests/kexec work from Mimi
Johar and Petr Vorel
- A framework to kselftest for writing kernel test modules addition
from Tobin C. Harding
* tag 'linux-kselftest-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (29 commits)
selftests: build and run gpio when output directory is the src dir
selftests/ipc: Fix msgque compiler warnings
selftests/efivarfs: clean up test files from test_create*()
selftests: fix headers_install circular dependency
selftests/kexec: update get_secureboot_mode
selftests/kexec: make kexec_load test independent of IMA being enabled
selftests/kexec: check kexec_load and kexec_file_load are enabled
selftests/kexec: Add missing '=y' to config options
selftests/kexec: kexec_file_load syscall test
selftests/kexec: define "require_root_privileges"
selftests/kexec: define common logging functions
selftests/kexec: define a set of common functions
selftests/kexec: cleanup the kexec selftest
selftests/kexec: move the IMA kexec_load selftest to selftests/kexec
selftests/harness: Add 30 second timeout per test
selftests/seccomp: Handle namespace failures gracefully
selftests: cgroup: fix cleanup path in test_memcg_subtree_control()
selftests: efivarfs: remove the test_create_read file if it was exist
rseq/selftests: Adapt number of threads to the number of detected cpus
lib: Add test module for strscpy_pad
...
Pull crypto update from Herbert Xu:
"API:
- Add support for AEAD in simd
- Add fuzz testing to testmgr
- Add panic_on_fail module parameter to testmgr
- Use per-CPU struct instead multiple variables in scompress
- Change verify API for akcipher
Algorithms:
- Convert x86 AEAD algorithms over to simd
- Forbid 2-key 3DES in FIPS mode
- Add EC-RDSA (GOST 34.10) algorithm
Drivers:
- Set output IV with ctr-aes in crypto4xx
- Set output IV in rockchip
- Fix potential length overflow with hashing in sun4i-ss
- Fix computation error with ctr in vmx
- Add SM4 protected keys support in ccree
- Remove long-broken mxc-scc driver
- Add rfc4106(gcm(aes)) cipher support in cavium/nitrox"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (179 commits)
crypto: ccree - use a proper le32 type for le32 val
crypto: ccree - remove set but not used variable 'du_size'
crypto: ccree - Make cc_sec_disable static
crypto: ccree - fix spelling mistake "protedcted" -> "protected"
crypto: caam/qi2 - generate hash keys in-place
crypto: caam/qi2 - fix DMA mapping of stack memory
crypto: caam/qi2 - fix zero-length buffer DMA mapping
crypto: stm32/cryp - update to return iv_out
crypto: stm32/cryp - remove request mutex protection
crypto: stm32/cryp - add weak key check for DES
crypto: atmel - remove set but not used variable 'alg_name'
crypto: picoxcell - Use dev_get_drvdata()
crypto: crypto4xx - get rid of redundant using_sd variable
crypto: crypto4xx - use sync skcipher for fallback
crypto: crypto4xx - fix cfb and ofb "overran dst buffer" issues
crypto: crypto4xx - fix ctr-aes missing output IV
crypto: ecrdsa - select ASN1 and OID_REGISTRY for EC-RDSA
crypto: ux500 - use ccflags-y instead of CFLAGS_<basename>.o
crypto: ccree - handle tee fips error during power management resume
crypto: ccree - add function to handle cryptocell tee fips error
...
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
...
Pull objtool updates from Ingo Molnar:
"This is a series from Peter Zijlstra that adds x86 build-time uaccess
validation of SMAP to objtool, which will detect and warn about the
following uaccess API usage bugs and weirdnesses:
- call to %s() with UACCESS enabled
- return with UACCESS enabled
- return with UACCESS disabled from a UACCESS-safe function
- recursive UACCESS enable
- redundant UACCESS disable
- UACCESS-safe disables UACCESS
As it turns out not leaking uaccess permissions outside the intended
uaccess functionality is hard when the interfaces are complex and when
such bugs are mostly dormant.
As a bonus we now also check the DF flag. We had at least one
high-profile bug in that area in the early days of Linux, and the
checking is fairly simple. The checks performed and warnings emitted
are:
- call to %s() with DF set
- return with DF set
- return with modified stack frame
- recursive STD
- redundant CLD
It's all x86-only for now, but later on this can also be used for PAN
on ARM and objtool is fairly cross-platform in principle.
While all warnings emitted by this new checking facility that got
reported to us were fixed, there might be GCC version dependent
warnings that were not reported yet - which we'll address, should they
trigger.
The warnings are non-fatal build warnings"
* 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
mm/uaccess: Use 'unsigned long' to placate UBSAN warnings on older GCC versions
x86/uaccess: Dont leak the AC flag into __put_user() argument evaluation
sched/x86_64: Don't save flags on context switch
objtool: Add Direction Flag validation
objtool: Add UACCESS validation
objtool: Fix sibling call detection
objtool: Rewrite alt->skip_orig
objtool: Add --backtrace support
objtool: Rewrite add_ignores()
objtool: Handle function aliases
objtool: Set insn->func for alternatives
x86/uaccess, kcov: Disable stack protector
x86/uaccess, ftrace: Fix ftrace_likely_update() vs. SMAP
x86/uaccess, ubsan: Fix UBSAN vs. SMAP
x86/uaccess, kasan: Fix KASAN vs SMAP
x86/smap: Ditch __stringify()
x86/uaccess: Introduce user_access_{save,restore}()
x86/uaccess, signal: Fix AC=1 bloat
x86/uaccess: Always inline user_access_begin()
x86/uaccess, xen: Suppress SMAP warnings
...
The kernel the kernel is built with -Wvla for some time, so is not
supposed to have any variable length arrays. Remove vla bounds checking
from ubsan since it's useless now.
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Building lib/ubsan.c with gcc-9 results in a ton of nasty warnings like
this one:
lib/ubsan.c warning: conflicting types for built-in function
‘__ubsan_handle_negate_overflow’; expected ‘void(void *, void *)’ [-Wbuiltin-declaration-mismatch]
The kernel's declarations of __ubsan_handle_*() often uses 'unsigned
long' types in parameters while GCC these parameters as 'void *' types,
hence the mismatch.
Fix this by using 'void *' to match GCC's declarations.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Fixes: c6d308534a ("UBSAN: run-time undefined behavior sanity checker")
Cc: <stable@vger.kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 fix from Ingo Molnar:
"Disable function tracing during early SME setup to fix a boot crash on
SME-enabled kernels running distro kernels (some of which have
function tracing enabled)"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm/mem_encrypt: Disable all instrumentation for early SME setup
Add new validation flag NL_VALIDATE_NESTED which adds three consistency
checks of NLA_F_NESTED_FLAG:
- the flag is set on attributes with NLA_NESTED{,_ARRAY} policy
- the flag is not set on attributes with other policies except NLA_UNSPEC
- the flag is set on attribute passed to nla_parse_nested()
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
v2: change error messages to mention NLA_F_NESTED explicitly
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The check that attribute type is within 0...maxtype range in
__nla_validate_parse() sets only error message but not bad_attr in extack.
Set also bad_attr to tell userspace which attribute failed validation.
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This provides an unified API for accessing register bit fields
regardless of memory layout. The basic unit of data for these API
functions is the u64. The process of transforming an u64 from native CPU
encoding into the peripheral's encoding is called 'pack', and
transforming it from peripheral to native CPU encoding is 'unpack'.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 1fd7c3b438 ("kobject: Improve doc clarity kobject_init_and_add()")
tried to provide more clarity, but the reference to kobject_del() was
incorrect. Fix that up by removing that line, and hopefully be more explicit
as to exactly what needs to happen here once you register a kobject with the
kobject core.
Acked-by: Tobin C. Harding <tobin@kernel.org>
Fixes: 1fd7c3b438 ("kobject: Improve doc clarity kobject_init_and_add()")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel-doc comments have a prescribed format. This includes parenthesis
on the function name. To be _particularly_ correct we should also
capitalise the brief description and terminate it with a period.
In preparation for adding/updating kernel-doc function comments clean up
the ones currently present.
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the docstring for kobject_get_path() mentions 'kset'. The
kset is not used in the function callchain starting from this function.
Remove docstring reference to kset from the function kobject_get_path().
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The kobj pointer is being null-checked so potentially it could be null,
however, the ktype declaration before the null check is dereferencing kobj
hence we have a potential null pointer deference. Fix this by moving the
assignment of ktype after kobj has been null checked.
Addresses-Coverity: ("Dereference before null check")
Fixes: aa30f47cf6 ("kobject: Add support for default attribute groups to kobj_type")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Enablement of AMD's Secure Memory Encryption feature is determined very
early after start_kernel() is entered. Part of this procedure involves
scanning the command line for the parameter 'mem_encrypt'.
To determine intended state, the function sme_enable() uses library
functions cmdline_find_option() and strncmp(). Their use occurs early
enough such that it cannot be assumed that any instrumentation subsystem
is initialized.
For example, making calls to a KASAN-instrumented function before KASAN
is set up will result in the use of uninitialized memory and a boot
failure.
When AMD's SME support is enabled, conditionally disable instrumentation
of these dependent functions in lib/string.c and arch/x86/lib/cmdline.c.
[ bp: Get rid of intermediary nostackp var and cleanup whitespace. ]
Fixes: aca20d5462 ("x86/mm: Add support to make use of Secure Memory Encryption")
Reported-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: Coly Li <colyli@suse.de>
Cc: "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: "luto@kernel.org" <luto@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "mingo@redhat.com" <mingo@redhat.com>
Cc: "peterz@infradead.org" <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/155657657552.7116.18363762932464011367.stgit@sosrh3.amd.com
Fix sparse warning:
lib/vsprintf.c:673:6: warning:
symbol 'pointer_string' was not declared. Should it be static?
Link: http://lkml.kernel.org/r/20190426164630.22104-1-yuehaibing@huawei.com
To: <sergey.senozhatsky@gmail.com>
To: <andriy.shevchenko@linux.intel.com>
To: <geert+renesas@glider.be>
To: <rostedt@goodmis.org>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
All architectures which support stacktrace carry duplicated code and
do the stack storage and filtering at the architecture side.
Provide a consolidated interface with a callback function for consuming the
stack entries provided by the architecture specific stack walker. This
removes lots of duplicated code and allows to implement better filtering
than 'skip number of entries' in the future without touching any
architecture specific code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: linux-arch@vger.kernel.org
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: linux-mm@kvack.org
Cc: David Rientjes <rientjes@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: kasan-dev@googlegroups.com
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: linux-btrfs@vger.kernel.org
Cc: dm-devel@redhat.com
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/20190425094803.713568606@linutronix.de
Function kobject_init_and_add() is currently misused in a number of
places in the kernel. On error return kobject_put() must be called but
is at times not.
Make the function documentation more explicit about calling
kobject_put() in the error path.
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is currently some confusion on how to wind back
kobject_init_and_add() during the error paths in code that uses this
function.
Add documentation to kobject_add() and kobject_del() to help clarify the
usage.
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Unfortunately, we cannot add strict parsing for all attributes, as
that would break existing userspace. We currently warn about it, but
that's about all we can do.
For new attributes, however, the story is better: nobody is using
them, so we can reject bad sizes.
Also, for new attributes, we need not accept them when the policy
doesn't declare their usage.
David Ahern and I went back and forth on how to best encode this, and
the best way we found was to have a "boundary type", from which point
on new attributes have all possible validation applied, and NLA_UNSPEC
is rejected.
As we didn't want to add another argument to all functions that get a
netlink policy, the workaround is to encode that boundary in the first
entry of the policy array (which is for type 0 and thus probably not
really valid anyway). I put it into the validation union for the rare
possibility that somebody is actually using attribute 0, which would
continue to work fine unless they tried to use the extended validation,
which isn't likely. We also didn't find any in-tree users with type 0.
The reason for setting the "start strict here" attribute is that we
never really need to start strict from 0, which is invalid anyway (or
in legacy families where that isn't true, it cannot be set to strict),
so we can thus reserve the value 0 for "don't do this check" and don't
have to add the tag to all policies right now.
Thus, policies can now opt in to this validation, which we should do
for all existing policies, at least when adding new attributes.
Note that entirely *new* policies won't need to set it, as the use
of that should be using nla_parse()/nlmsg_parse() etc. which anyway
do fully strict validation now, regardless of this.
So in effect, this patch only covers the "existing command with new
attribute" case.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We currently have two levels of strict validation:
1) liberal (default)
- undefined (type >= max) & NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
- garbage at end of message accepted
2) strict (opt-in)
- NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
Split out parsing strictness into four different options:
* TRAILING - check that there's no trailing data after parsing
attributes (in message or nested)
* MAXTYPE - reject attrs > max known type
* UNSPEC - reject attributes with NLA_UNSPEC policy entries
* STRICT_ATTRS - strictly validate attribute size
The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().
Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.
We end up with the following renames:
* nla_parse -> nla_parse_deprecated
* nla_parse_strict -> nla_parse_deprecated_strict
* nlmsg_parse -> nlmsg_parse_deprecated
* nlmsg_parse_strict -> nlmsg_parse_deprecated_strict
* nla_parse_nested -> nla_parse_nested_deprecated
* nla_validate_nested -> nla_validate_nested_deprecated
Using spatch, of course:
@@
expression TB, MAX, HEAD, LEN, POL, EXT;
@@
-nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
+nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression TB, MAX, NLA, POL, EXT;
@@
-nla_parse_nested(TB, MAX, NLA, POL, EXT)
+nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)
@@
expression START, MAX, POL, EXT;
@@
-nla_validate_nested(START, MAX, POL, EXT)
+nla_validate_nested_deprecated(START, MAX, POL, EXT)
@@
expression NLH, HDRLEN, MAX, POL, EXT;
@@
-nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
+nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)
For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.
Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.
Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.
In effect then, this adds fully strict validation for any new command.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rather than using NLA_UNSPEC for this type of thing, use NLA_MIN_LEN
so we can make NLA_UNSPEC be NLA_REJECT under certain conditions for
future attributes.
While at it, also use NLA_EXACT_LEN for the struct example.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On my "Intel(R) Xeon(R) W-2135 CPU @ 3.70GHz" system(12 CPUs) i get the
warning from the compiler about frame size:
warning: the frame size of 1096 bytes is larger than 1024 bytes [-Wframe-larger-than=]
the size of cpumask_t depends on number of CPUs, therefore just make use
of cpumask_of() in set_cpus_allowed_ptr() as a second argument.
Link: http://lkml.kernel.org/r/20190418193925.9361-1-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If CONFIG_TEST_KMOD is set to M, while CONFIG_BLOCK is not set, XFS and
BTRFS can not be compiled successly.
Link: http://lkml.kernel.org/r/20190410075434.35220-1-yuehaibing@huawei.com
Fixes: d9c6a72d6f ("kmod: add test driver to stress test the module loader")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The inlined error messages must be used carefully because
they need to fit into the given buffer.
Handle them using a custom wrapper that makes people aware
of the problem. Also define a reasonable hard limit to
avoid a completely insane usage.
Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Link: http://lkml.kernel.org/r/20190417115350.20479-11-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
We are able to detect invalid values handled by %p[iI] printk specifier.
The current error message is "invalid address". It might cause confusion
against "(efault)" reported by the generic valid_pointer_address() check.
Let's unify the style and use the more appropriate error code description
"(einval)".
Link: http://lkml.kernel.org/r/20190417115350.20479-10-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
We already prevent crash when dereferencing some obviously broken
pointers. But the handling is not consistent. Sometimes we print "(null)"
only for pure NULL pointer, sometimes for pointers in the first
page and sometimes also for pointers in the last page (error codes).
Note that printk() call this code under logbuf_lock. Any recursive
printks are redirected to the printk_safe implementation and the messages
are stored into per-CPU buffers. These buffers might be eventually flushed
in printk_safe_flush_on_panic() but it is not guaranteed.
This patch adds a check using probe_kernel_read(). It is not a full-proof
test. But it should help to see the error message in 99% situations where
the kernel would silently crash otherwise.
Also it makes the error handling unified for "%s" and the many %p*
specifiers that need to read the data from a given address. We print:
+ (null) when accessing data on pure pure NULL address
+ (efault) when accessing data on an invalid address
It does not affect the %p* specifiers that just print the given address
in some form, namely %pF, %pf, %pS, %ps, %pB, %pK, %px, and plain %p.
Note that we print (efault) from security reasons. In fact, the real
address can be seen only by %px or eventually %pK.
Link: http://lkml.kernel.org/r/20190417115350.20479-9-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
There are few printk formats that make sense only with two or more
specifiers. Also some specifiers make sense only when a kernel feature
is enabled.
The handling of unknown specifiers is inconsistent and not helpful.
Using WARN() looks like an overkill for this type of error. pr_warn()
is not good either. It would by handled via printk_safe buffer and
it might be hard to match it with the problematic string.
A reasonable compromise seems to be writing the unknown format specifier
into the original string with a question mark, for example (%pC?).
It should be self-explaining enough. Note that it is in brackets
to follow the (null) style.
Note that it introduces a warning about that test_hashed() function
is unused. It is going to be used again by a later patch.
Link: http://lkml.kernel.org/r/20190417115350.20479-8-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Move code from the long pointer() function. We are going to improve
error handling that will make it even more complicated.
This patch does not change the existing behavior.
Link: http://lkml.kernel.org/r/20190417115350.20479-7-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Move the code from the long pointer() function. We are going to improve
error handling that will make it more complicated.
This patch does not change the existing behavior.
Link: http://lkml.kernel.org/r/20190417115350.20479-6-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Move the non-trivial code from the long pointer() function. We are going
to improve error handling that will make it even more complicated.
This patch does not change the existing behavior.
Link: http://lkml.kernel.org/r/20190417115350.20479-5-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
We are going to check the address using probe_kernel_address(). It will
be more expensive and it does not make sense for well known address.
This patch splits the string() function. The variant without the check
is then used on locations that handle string constants or strings defined
as local variables.
This patch does not change the existing behavior.
Link: http://lkml.kernel.org/r/20190417115350.20479-4-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
restricted_pointer() pretends that it prints the address when kptr_restrict
is set to zero. But it is never called in this situation. Instead,
pointer() falls back to ptr_to_id() and hashes the pointer.
This patch removes the potential confusion. klp_restrict is checked only
in restricted_pointer().
It actually fixes a small race when the address might get printed unhashed:
CPU0 CPU1
pointer()
if (!kptr_restrict)
/* for example set to 2 */
restricted_pointer()
/* echo 0 >/proc/sys/kernel/kptr_restrict */
proc_dointvec_minmax_sysadmin()
klpr_restrict = 0;
switch(kptr_restrict)
case 0:
break:
number()
Fixes: ef0010a309 ("vsprintf: don't use 'restricted_pointer()' when not restricting")
Link: http://lkml.kernel.org/r/20190417115350.20479-3-pmladek@suse.com
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
This is just a preparation step for further changes.
The patch does not change the code.
Link: http://lkml.kernel.org/r/20190417115350.20479-2-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
kobj_type currently uses a list of individual attributes to store
default attributes. Attribute groups are more flexible than a list of
attributes because groups provide support for attribute visibility. So,
add support for default attribute groups to kobj_type.
In future patches, the existing uses of kobj_type’s attribute list will
be converted to attribute groups. When that is complete, kobj_type’s
attribute list, “default_attrs”, will be removed.
Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
This patch aims to suppress up to 18 missing-break-in-switch false
positives on some architectures.
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The flags field in 'struct shash_desc' never actually does anything.
The only ostensibly supported flag is CRYPTO_TFM_REQ_MAY_SLEEP.
However, no shash algorithm ever sleeps, making this flag a no-op.
With this being the case, inevitably some users who can't sleep wrongly
pass MAY_SLEEP. These would all need to be fixed if any shash algorithm
actually started sleeping. For example, the shash_ahash_*() functions,
which wrap a shash algorithm with the ahash API, pass through MAY_SLEEP
from the ahash API to the shash API. However, the shash functions are
called under kmap_atomic(), so actually they're assumed to never sleep.
Even if it turns out that some users do need preemption points while
hashing large buffers, we could easily provide a helper function
crypto_shash_update_large() which divides the data into smaller chunks
and calls crypto_shash_update() and cond_resched() for each chunk. It's
not necessary to have a flag in 'struct shash_desc', nor is it necessary
to make individual shash algorithms aware of this at all.
Therefore, remove shash_desc::flags, and document that the
crypto_shash_*() functions can be called from any context.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Randy reported objtool triggered on his (GCC-7.4) build:
lib/strncpy_from_user.o: warning: objtool: strncpy_from_user()+0x315: call to __ubsan_handle_add_overflow() with UACCESS enabled
lib/strnlen_user.o: warning: objtool: strnlen_user()+0x337: call to __ubsan_handle_sub_overflow() with UACCESS enabled
This is due to UBSAN generating signed-overflow-UB warnings where it
should not. Prior to GCC-8 UBSAN ignored -fwrapv (which the kernel
uses through -fno-strict-overflow).
Make the functions use 'unsigned long' throughout.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: luto@kernel.org
Link: http://lkml.kernel.org/r/20190424072208.754094071@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Move the code to implement uaccess using memcpy or direct loads and
stores to asm-generic/uaccess.h and make it selectable kconfig option.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
-----BEGIN PGP SIGNATURE-----
iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAly8rGYeHHRvcnZhbGRz
QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGmZMH/1IRB0E1Qmzz8yzw
wj79UuRGYPqxDDSWW+wNc8sU4Ic7iYirn9APHAztCdQqsjmzU/OVLfSa3JhdBe5w
THo7pbGKBqEDcWnKfNk/21jXFNLZ1vr9BoQv2DGU2MMhHAyo/NZbalo2YVtpQPmM
OCRth5n+LzvH7rGrX7RYgWu24G9l3NMfgtaDAXBNXesCGFAjVRrdkU5CBAaabvtU
4GWh/nnutndOOLdByL3x+VZ3H3fIBnbNjcIGCglvvqzk7h3hrfGEl4UCULldTxcM
IFsfMUhSw1ENy7F6DHGbKIG90cdCJcrQ8J/ziEzjj/KLGALluutfFhVvr6YCM2J6
2RgU8CY=
=CfY1
-----END PGP SIGNATURE-----
Merge tag 'v5.1-rc6' into for-5.2/block
Pull in v5.1-rc6 to resolve two conflicts. One is in BFQ, in just a
comment, and is trivial. The other one is a conflict due to a later fix
in the bio multi-page work, and needs a bit more care.
* tag 'v5.1-rc6': (770 commits)
Linux 5.1-rc6
block: make sure that bvec length can't be overflow
block: kill all_q_node in request_queue
x86/cpu/intel: Lower the "ENERGY_PERF_BIAS: Set to normal" message's log priority
coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping
mm/kmemleak.c: fix unused-function warning
init: initialize jump labels before command line option parsing
kernel/watchdog_hld.c: hard lockup message should end with a newline
kcov: improve CONFIG_ARCH_HAS_KCOV help text
mm: fix inactive list balancing between NUMA nodes and cgroups
mm/hotplug: treat CMA pages as unmovable
proc: fixup proc-pid-vm test
proc: fix map_files test on F29
mm/vmstat.c: fix /proc/vmstat format for CONFIG_DEBUG_TLBFLUSH=y CONFIG_SMP=n
mm/memory_hotplug: do not unlock after failing to take the device_hotplug_lock
mm: swapoff: shmem_unuse() stop eviction without igrab()
mm: swapoff: take notice of completion sooner
mm: swapoff: remove too limiting SWAP_UNUSE_MAX_TRIES
mm: swapoff: shmem_find_swap_entries() filter out other types
slab: store tagged freelist for off-slab slabmgmt
...
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The help text for CONFIG_ARCH_HAS_KCOV is stale, and describes the
feature as being enabled only for x86_64, when it is now enabled for
several architectures, including arm, arm64, powerpc, and s390.
Let's remove that stale help text, and update it along the lines of hat
for ARCH_HAS_FORTIFY_SOURCE, better describing when an architecture
should select CONFIG_ARCH_HAS_KCOV.
Link: http://lkml.kernel.org/r/20190412102733.5154-1-mark.rutland@arm.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As reported by Guenter Roeck, the new bit-locking using
BIT(1) doesn't work on the m68k architecture. m68k only requires
2-byte alignment for words and longwords, so there is only one
unused bit in pointers to structs - We current use two, one for the
NULLS marker at the end of the linked list, and one for the bit-lock
in the head of the list.
The two uses don't need to conflict as we never need the head of the
list to be a NULLS marker - the marker is only needed to check if an
object has moved to a different table, and the bucket head cannot
move. The NULLS marker is only needed in a ->next pointer.
As we already have different types for the bucket head pointer (struct
rhash_lock_head) and the ->next pointers (struct rhash_head), it is
fairly easy to treat the lsb differently in each.
So: Initialize buckets heads to NULL, and use the lsb for locking.
When loading the pointer from the bucket head, if it is NULL (ignoring
the lock big), report as being the expected NULLS marker.
When storing a value into a bucket head, if it is a NULLS marker,
store NULL instead.
And convert all places that used bit 1 for locking, to use bit 0.
Fixes: 8f0db01800 ("rhashtable: use bit_spin_locks to protect hash bucket.")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The only times rht_ptr_locked() is used, it is to store a new
value in a bucket-head. This is the only time it makes sense
to use it too. So replace it by a function which does the
whole task: Sets the lock bit and assigns to a bucket head.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rather than dereferencing a pointer to a bucket and then passing the
result to rht_ptr(), we now pass in the pointer and do the dereference
in rht_ptr().
This requires that we pass in the tbl and hash as well to support RCU
checks, and means that the various rht_for_each functions can expect a
pointer that can be dereferenced without further care.
There are two places where we dereference a bucket pointer
where there is no testable protection - in each case we know
that we much have exclusive access without having taken a lock.
The previous code used rht_dereference() to pretend that holding
the mutex provided protects, but holding the mutex never provides
protection for accessing buckets.
So instead introduce rht_ptr_exclusive() that can be used when
there is known to be exclusive access without holding any locks.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With these annotations, the rhashtable now gets no
warnings when compiled with "C=1" for sparse checking.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along with
memory for some number of elements for that array. For example:
struct foo {
int stuff;
struct boo entry[];
};
size = sizeof(struct foo) + count * sizeof(struct boo);
instance = kvzalloc(size, GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kvzalloc(struct_size(instance, entry, count), GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
pull-request: bpf-next 2019-04-12
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Improve BPF verifier scalability for large programs through two
optimizations: i) remove verifier states that are not useful in pruning,
ii) stop walking parentage chain once first LIVE_READ is seen. Combined
gives approx 20x speedup. Increase limits for accepting large programs
under root, and add various stress tests, from Alexei.
2) Implement global data support in BPF. This enables static global variables
for .data, .rodata and .bss sections to be properly handled which allows
for more natural program development. This also opens up the possibility
to optimize program workflow by compiling ELFs only once and later only
rewriting section data before reload, from Daniel and with test cases and
libbpf refactoring from Joe.
3) Add config option to generate BTF type info for vmlinux as part of the
kernel build process. DWARF debug info is converted via pahole to BTF.
Latter relies on libbpf and makes use of BTF deduplication algorithm which
results in 100x savings compared to DWARF data. Resulting .BTF section is
typically about 2MB in size, from Andrii.
4) Add BPF verifier support for stack access with variable offset from
helpers and add various test cases along with it, from Andrey.
5) Extend bpf_skb_adjust_room() growth BPF helper to mark inner MAC header
so that L2 encapsulation can be used for tc tunnels, from Alan.
6) Add support for input __sk_buff context in BPF_PROG_TEST_RUN so that
users can define a subset of allowed __sk_buff fields that get fed into
the test program, from Stanislav.
7) Add bpf fs multi-dimensional array tests for BTF test suite and fix up
various UBSAN warnings in bpftool, from Yonghong.
8) Generate a pkg-config file for libbpf, from Luca.
9) Dump program's BTF id in bpftool, from Prashant.
10) libbpf fix to use smaller BPF log buffer size for AF_XDP's XDP
program, from Magnus.
11) kallsyms related fixes for the case when symbols are not present in
BPF selftests and samples, from Daniel
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull misc fixes from Al Viro:
"A few regression fixes from this cycle"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
aio: use kmem_cache_free() instead of kfree()
iov_iter: Fix build error without CONFIG_CRYPTO
aio: Fix an error code in __io_submit_one()
In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.
This patch fixes the following warnings:
lib/asn1_decoder.c:386:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/asn1_decoder.c:449:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
Warning level 3 was used: -Wimplicit-fallthrough=3
This patch is part of the ongoing efforts to enabling
-Wimplicit-fallthrough.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.
This patch fixes the following warnings:
lib/cmdline.c:137:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/cmdline.c:140:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/cmdline.c:143:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/cmdline.c:146:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/cmdline.c:149:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
Warning level 3 was used: -Wimplicit-fallthrough=3
This patch is part of the ongoing efforts to enabling -Wimplicit-fallthrough.
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.
This patch fixes the following warnings:
lib/zstd/bitstream.h:261:30: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/zstd/bitstream.h:262:30: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/zstd/bitstream.h:263:30: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/zstd/bitstream.h:264:30: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/zstd/bitstream.h:265:30: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/zstd/compress.c:3183:16: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/zstd/decompress.c:1770:18: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/zstd/decompress.c:2376:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/zstd/decompress.c:2404:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/zstd/decompress.c:2435:16: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/zstd/huf_compress.c: In function ‘HUF_compress1X_usingCTable’:
lib/zstd/huf_compress.c:535:5: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (sizeof((stream)->bitContainer) * 8 < HUF_TABLELOG_MAX * 4 + 7) \
^
lib/zstd/huf_compress.c:558:54: note: in expansion of macro ‘HUF_FLUSHBITS_2’
case 3: HUF_encodeSymbol(&bitC, ip[n + 2], CTable); HUF_FLUSHBITS_2(&bitC);
^~~~~~~~~~~~~~~
lib/zstd/huf_compress.c:559:2: note: here
case 2: HUF_encodeSymbol(&bitC, ip[n + 1], CTable); HUF_FLUSHBITS_1(&bitC);
^~~~
lib/zstd/huf_compress.c:531:5: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (sizeof((stream)->bitContainer) * 8 < HUF_TABLELOG_MAX * 2 + 7) \
^
lib/zstd/huf_compress.c:559:54: note: in expansion of macro ‘HUF_FLUSHBITS_1’
case 2: HUF_encodeSymbol(&bitC, ip[n + 1], CTable); HUF_FLUSHBITS_1(&bitC);
^~~~~~~~~~~~~~~
lib/zstd/huf_compress.c:560:2: note: here
case 1: HUF_encodeSymbol(&bitC, ip[n + 0], CTable); HUF_FLUSHBITS(&bitC);
^~~~
AR lib/zstd//built-in.a
Warning level 3 was used: -Wimplicit-fallthrough=3
This patch is part of the ongoing efforts to enabling -Wimplicit-fallthrough.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Add a test module for the new strscpy_pad() function. Tie it into the
kselftest infrastructure for lib/ tests.
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>
We have a function to copy strings safely and we have a function to copy
strings and zero the tail of the destination (if source string is
shorter than destination buffer) but we do not have a function to do
both at once. This means developers must write this themselves if they
desire this functionality. This is a chore, and also leaves us open to
off by one errors unnecessarily.
Add a function that calls strscpy() then memset()s the tail to zero if
the source string is shorter than the destination buffer.
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>
We just added a new C header file for use with test modules that are
intended to be run with kselftest. We can reduce code duplication by
using this header.
Use new kselftest header to reduce code duplication in test_printf and
test_bitmap test modules.
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>
Currently the test_printf module does not have an exit function, this
prevents the module from being unloaded. If we cannot unload the
module we cannot run the tests a second time.
Add an empty exit function.
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>
Native bit_spin_locks are not tracked by lockdep.
The bit_spin_locks used for rhashtable buckets are local
to the rhashtable implementation, so there is little opportunity
for the sort of misuse that lockdep might detect.
However locks are held while a hash function or compare
function is called, and if one of these took a lock,
a misbehaviour is possible.
As it is quite easy to add lockdep support this unlikely
possibility seems to be enough justification.
So create a lockdep class for bucket bit_spin_lock and attach
through a lockdep_map in each bucket_table.
Without the 'nested' annotation in rhashtable_rehash_one(), lockdep
correctly reports a possible problem as this lock is taken
while another bucket lock (in another table) is held. This
confirms that the added support works.
With the correct nested annotation in place, lockdep reports
no problems.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch changes rhashtables to use a bit_spin_lock on BIT(1) of the
bucket pointer to lock the hash chain for that bucket.
The benefits of a bit spin_lock are:
- no need to allocate a separate array of locks.
- no need to have a configuration option to guide the
choice of the size of this array
- locking cost is often a single test-and-set in a cache line
that will have to be loaded anyway. When inserting at, or removing
from, the head of the chain, the unlock is free - writing the new
address in the bucket head implicitly clears the lock bit.
For __rhashtable_insert_fast() we ensure this always happens
when adding a new key.
- even when lockings costs 2 updates (lock and unlock), they are
in a cacheline that needs to be read anyway.
The cost of using a bit spin_lock is a little bit of code complexity,
which I think is quite manageable.
Bit spin_locks are sometimes inappropriate because they are not fair -
if multiple CPUs repeatedly contend of the same lock, one CPU can
easily be starved. This is not a credible situation with rhashtable.
Multiple CPUs may want to repeatedly add or remove objects, but they
will typically do so at different buckets, so they will attempt to
acquire different locks.
As we have more bit-locks than we previously had spinlocks (by at
least a factor of two) we can expect slightly less contention to
go with the slightly better cache behavior and reduced memory
consumption.
To enhance type checking, a new struct is introduced to represent the
pointer plus lock-bit
that is stored in the bucket-table. This is "struct rhash_lock_head"
and is empty. A pointer to this needs to be cast to either an
unsigned lock, or a "struct rhash_head *" to be useful.
Variables of this type are most often called "bkt".
Previously "pprev" would sometimes point to a bucket, and sometimes a
->next pointer in an rhash_head. As these are now different types,
pprev is NULL when it would have pointed to the bucket. In that case,
'blk' is used, together with correct locking protocol.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rather than returning a pointer to a static nulls, rht_bucket_var()
now returns NULL if the bucket doesn't exist.
This will make the next patch, which stores a bitlock in the
bucket pointer, somewhat cleaner.
This change involves introducing __rht_bucket_nested() which is
like rht_bucket_nested(), but doesn't provide the static nulls,
and changing rht_bucket_nested() to call this and possible
provide a static nulls - as is still needed for the non-var case.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
nested_table_alloc() relies on the fact that there is
at most one spinlock allocated for every slot in the top
level nested table, so it is not possible for two threads
to try to allocate the same table at the same time.
This assumption is a little fragile (it is not explicit) and is
unnecessary as cmpxchg() can be used instead.
A future patch will replace the spinlocks by per-bucket bitlocks,
and then we won't be able to protect the slot pointer with a spinlock.
So replace rcu_assign_pointer() with cmpxchg() - which has equivalent
barrier properties.
If it the cmp fails, free the table that was just allocated.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently support for 64-bit sector_t and blkcnt_t is optional on 32-bit
architectures. These types are required to support block device and/or
file sizes larger than 2 TiB, and have generally defaulted to on for
a long time. Enabling the option only increases the i386 tinyconfig
size by 145 bytes, and many data structures already always use
64-bit values for their in-core and on-disk data structures anyway,
so there should not be a large change in dynamic memory usage either.
Dropping this option removes a somewhat weird non-default config that
has cause various bugs or compiler warnings when actually used.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge misc fixes from Andrew Morton:
"14 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
kernel/sysctl.c: fix out-of-bounds access when setting file-max
mm/util.c: fix strndup_user() comment
sh: fix multiple function definition build errors
MAINTAINERS: add maintainer and replacing reviewer ARM/NUVOTON NPCM
MAINTAINERS: fix bad pattern in ARM/NUVOTON NPCM
mm: writeback: use exact memcg dirty counts
psi: clarify the units used in pressure files
mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()
hugetlbfs: fix memory leak for resv_map
mm: fix vm_fault_t cast in VM_FAULT_GET_HINDEX()
lib/lzo: fix bugs for very short or empty input
include/linux/bitrev.h: fix constant bitrev
kmemleak: powerpc: skip scanning holes in the .bss section
lib/string.c: implement a basic bcmp
For very short input data (0 - 1 bytes), lzo-rle was not behaving
correctly. Fix this behaviour and update documentation accordingly.
For zero-length input, lzo v0 outputs an end-of-stream marker only,
which was misinterpreted by lzo-rle as a bitstream version number.
Ensure bitstream versions > 0 require a minimum stream length of 5.
Also fixes a bug in handling the tail for very short inputs when a
bitstream version is present.
Link: http://lkml.kernel.org/r/20190326165857.34613-1-dave.rodgman@arm.com
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yury Norov