DEVICE_ATTR is a declaration macro that has a few alternate and
preferred forms like DEVICE_ATTR_RW, DEVICE_ATTR_RO, and DEVICE_ATTR.
As well, many uses of DEVICE_ATTR could use the preferred forms when the
show or store functions are also named in a regular form.
Suggest the preferred forms when appropriate.
Also emit a permissions warning if the the permissions are not the
typical 0644, 0444, or 0200.
Link: http://lkml.kernel.org/r/725864f363d91d1e1e6894a39fb57662eabd6d65.1513803306.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Given this patch context,
+#define EFI_ST_DISK_IMG { \
+ 0x00000240, "\xbe\x5b\x7c\xac\x22\xc0\x74\x0b" /* .[|.".t. */ \
+ }
the current code misreports a quoted string line continuation defect as
there is a single quote in comment.
The 'raw' line should not be tested for quote count, the comment
substituted line should be instead.
Link: http://lkml.kernel.org/r/13f2735df10c33ca846e26f42f5cce6618157200.1513698599.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
module_param and create_proc uses with a permissions use of a single 0 are
"special" and should not emit any warning.
module_param uses with permission 0 are not visible in sysfs
create_proc uses with permission 0 use a default permission
Link: http://lkml.kernel.org/r/b6583611bb529ea6f6d43786827fddbabbab0a71.1513190059.git.joe@perches.com
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow lines with URL to exceed the 80 char limit for improved interaction
in adaption to ongoing but undocumented practice.
$ git grep -E '://\S{77}.*' -- '*.[ch]'
As per RFC3986 [1], the URL format allows for alphanum, +, - and .
characters in the scheme before the separator :// as long as it starts
with a letter (e.g. https, git, f.-+).
Recognition of URIs without more context information is prone to false
positives and thus currently left out of the heuristics.
$rawline is used in the check as comments are removed from $line.
[1] https://tools.ietf.org/html/rfc3986#section-3.1
Link: http://lkml.kernel.org/r/1511355432.12667.15.camel@elementarea.net
Signed-off-by: Andreas Brauchli <andreas.brauchli@sensirion.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
test_sort.c performs array-based and linked list sort test. Code allows
to compile either as a loadable modules or builtin into the kernel.
Current code is not allow to unload the test_sort.ko module after
successful completion.
This patch adds support to unload the "test_sort.ko" module by adding
module_exit support.
Previous patch was implemented auto unload support by returning -EAGAIN
from module_init() function on successful case, but this approach is not
ideal.
The auto-unload might seem like a nice optimization, but it encourages
inconsistent behaviour. And behaviour that is different from all other
normal modules.
Link: http://lkml.kernel.org/r/1513967133-6843-1-git-send-email-pravin.shedge4linux@gmail.com
Signed-off-by: Pravin Shedge <pravin.shedge4linux@gmail.com>
Cc: Kostenzer Felix <fkostenzer@live.at>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No need to get into the submenu to disable all related config entries.
This makes it easier to disable all RUNTIME_TESTS config options without
entering the submenu. It will also enable one to see that en/dis-abled
state from the outside menu.
This is only intended to change menuconfig UI, not change the config
dependencies.
Link: http://lkml.kernel.org/r/20171209162742.7363-1-vincent.legoll@gmail.com
Signed-off-by: Vincent Legoll <vincent.legoll@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
stackdepot used to call memcmp(), which compiler tools normally
instrument, therefore every lookup used to unnecessarily call instrumented
code. This is somewhat ok in the case of KASAN, but under KMSAN a lot of
time was spent in the instrumentation.
Link: http://lkml.kernel.org/r/20171117172149.69562-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Behaviour of bitmap_fill() differs from bitmap_zero() in a way how bits
behind bitmap are handed. bitmap_zero() clears entire bitmap by unsigned
long boundary, while bitmap_fill() mimics bitmap_set().
Here we change bitmap_fill() behaviour to be consistent with bitmap_zero()
and add a note to documentation.
The change might reveal some bugs in the code where unused bits are
handled differently and in such cases bitmap_set() has to be used.
Link: http://lkml.kernel.org/r/20180109172430.87452-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since we have separate explicit test cases for bitmap_zero() /
bitmap_clear() and bitmap_fill() / bitmap_set(), clean up
test_zero_fill_copy() to only test bitmap_copy() functionality and thus
rename a function to reflect the changes.
While here, replace bitmap_fill() by bitmap_set() with proper values.
Link: http://lkml.kernel.org/r/20180109172430.87452-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Yury Norov <ynorov@caviumnetworks.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Explicitly test bitmap_fill() and bitmap_set() functions.
For bitmap_fill() we expect a consistent behaviour as in bitmap_zero(),
i.e. the trailing bits will be set up to unsigned long boundary.
Link: http://lkml.kernel.org/r/20180109172430.87452-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Yury Norov <ynorov@caviumnetworks.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
with bitmap_{from,to}_arr32 over the kernel. Additionally to it:
* __check_eq_bitmap() now takes single nbits argument.
* __check_eq_u32_array is not used in new test but may be used in
future. So I don't remove it here, but annotate as __used.
Tested on arm64 and 32-bit BE mips.
[arnd@arndb.de: perf: arm_dsu_pmu: convert to bitmap_from_arr32]
Link: http://lkml.kernel.org/r/20180201172508.5739-2-ynorov@caviumnetworks.com
[ynorov@caviumnetworks.com: fix net/core/ethtool.c]
Link: http://lkml.kernel.org/r/20180205071747.4ekxtsbgxkj5b2fz@yury-thinkpad
Link: http://lkml.kernel.org/r/20171228150019.27953-2-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: David Decotigny <decot@googlers.com>,
Cc: David S. Miller <davem@davemloft.net>,
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchset replaces bitmap_{to,from}_u32array with more simple and
standard looking copy-like functions.
bitmap_from_u32array() takes 4 arguments (bitmap_to_u32array is similar):
- unsigned long *bitmap, which is destination;
- unsigned int nbits, the length of destination bitmap, in bits;
- const u32 *buf, the source; and
- unsigned int nwords, the length of source buffer in ints.
In description to the function it is detailed like:
* copy min(nbits, 32*nwords) bits from @buf to @bitmap, remaining
* bits between nword and nbits in @bitmap (if any) are cleared.
Having two size arguments looks unneeded and potentially dangerous.
It is unneeded because normally user of copy-like function should take
care of the size of destination and make it big enough to fit source
data.
And it is dangerous because function may hide possible error if user
doesn't provide big enough bitmap, and data becomes silently dropped.
That's why all copy-like functions have 1 argument for size of copying
data, and I don't see any reason to make bitmap_from_u32array()
different.
One exception that comes in mind is strncpy() which also provides size
of destination in arguments, but it's strongly argued by the possibility
of taking broken strings in source. This is not the case of
bitmap_{from,to}_u32array().
There is no many real users of bitmap_{from,to}_u32array(), and they all
very clearly provide size of destination matched with the size of
source, so additional functionality is not used in fact. Like this:
bitmap_from_u32array(to->link_modes.supported,
__ETHTOOL_LINK_MODE_MASK_NBITS,
link_usettings.link_modes.supported,
__ETHTOOL_LINK_MODE_MASK_NU32);
Where:
#define __ETHTOOL_LINK_MODE_MASK_NU32 \
DIV_ROUND_UP(__ETHTOOL_LINK_MODE_MASK_NBITS, 32)
In this patch, bitmap_copy_safe and bitmap_{from,to}_arr32 are introduced.
'Safe' in bitmap_copy_safe() stands for clearing unused bits in bitmap
beyond last bit till the end of last word. It is useful for hardening
API when bitmap is assumed to be exposed to userspace.
bitmap_{from,to}_arr32 functions are replacements for
bitmap_{from,to}_u32array. They don't take unneeded nwords argument, and
so simpler in implementation and understanding.
This patch suggests optimization for 32-bit systems - aliasing
bitmap_{from,to}_arr32 to bitmap_copy_safe.
Other possible optimization is aliasing 64-bit LE bitmap_{from,to}_arr32 to
more generic function(s). But I didn't end up with the function that would
be helpful by itself, and can be used to alias 64-bit LE
bitmap_{from,to}_arr32, like bitmap_copy_safe() does. So I preferred to
leave things as is.
The following patch switches kernel to new API and introduces test for it.
Discussion is here: https://lkml.org/lkml/2017/11/15/592
[ynorov@caviumnetworks.com: rename bitmap_copy_safe to bitmap_copy_clear_tail]
Link: http://lkml.kernel.org/r/20180201172508.5739-3-ynorov@caviumnetworks.com
Link: http://lkml.kernel.org/r/20171228150019.27953-1-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: David Decotigny <decot@googlers.com>,
Cc: David S. Miller <davem@davemloft.net>,
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace my codeaurora.org address with my kernel.org address so that
emails don't bounce.
Link: http://lkml.kernel.org/r/20180129173258.10643-1-sboyd@codeaurora.org
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 92266d6ef6 ("async: simplify lowest_in_progress()")
which was simply wrong: In the case where domain is NULL, we now use the
wrong offsetof() in the list_first_entry macro, so we don't actually
fetch the ->cookie value, but rather the eight bytes located
sizeof(struct list_head) further into the struct async_entry.
On 64 bit, that's the data member, while on 32 bit, that's a u64 built
from func and data in some order.
I think the bug happens to be harmless in practice: It obviously only
affects callers which pass a NULL domain, and AFAICT the only such
caller is
async_synchronize_full() ->
async_synchronize_full_domain(NULL) ->
async_synchronize_cookie_domain(ASYNC_COOKIE_MAX, NULL)
and the ASYNC_COOKIE_MAX means that in practice we end up waiting for
the async_global_pending list to be empty - but it would break if
somebody happened to pass (void*)-1 as the data element to
async_schedule, and of course also if somebody ever does a
async_synchronize_cookie_domain(, NULL) with a "finite" cookie value.
Maybe the "harmless in practice" means this isn't -stable material. But
I'm not completely confident my quick git grep'ing is enough, and there
might be affected code in one of the earlier kernels that has since been
removed, so I'll leave the decision to the stable guys.
Link: http://lkml.kernel.org/r/20171128104938.3921-1-linux@rasmusvillemoes.dk
Fixes: 92266d6ef6 "async: simplify lowest_in_progress()"
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Adam Wallis <awallis@codeaurora.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: <stable@vger.kernel.org> [3.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use a separate fd set for select()-s exception fds param to fix the
following gcc warning:
pager.c:36:12: error: passing argument 2 to restrict-qualified parameter aliases with argument 4 [-Werror=restrict]
select(1, &in, NULL, &in, NULL);
^~~ ~~~
Link: http://lkml.kernel.org/r/20180101105626.7168-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Exported header doesn't use anything from <linux/string.h>,
it is <linux/uuid.h> which uses memcmp().
Link: http://lkml.kernel.org/r/20171225171121.GA22754@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nearly all modern compilers support a stack-protector option, and nearly
all modern distributions enable the kernel stack-protector, so enabling
this by default in kernel builds would make sense. However, Kconfig does
not have knowledge of available compiler features, so it isn't safe to
force on, as this would unconditionally break builds for the compilers or
architectures that don't have support. Instead, this introduces a new
option, CONFIG_CC_STACKPROTECTOR_AUTO, which attempts to discover the best
possible stack-protector available, and will allow builds to proceed even
if the compiler doesn't support any stack-protector.
This option is made the default so that kernels built with modern
compilers will be protected-by-default against stack buffer overflows,
avoiding things like the recent BlueBorne attack. Selection of a specific
stack-protector option remains available, including disabling it.
Additionally, tiny.config is adjusted to use CC_STACKPROTECTOR_NONE, since
that's the option with the least code size (and it used to be the default,
so we have to explicitly choose it there now).
Link: http://lkml.kernel.org/r/1510076320-69931-4-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Various portions of the kernel, especially per-architecture pieces,
need to know if the compiler is building with the stack protector.
This was done in the arch/Kconfig with 'select', but this doesn't
allow a way to do auto-detected compiler support. In preparation for
creating an on-if-available default, move the logic for the definition of
CONFIG_CC_STACKPROTECTOR into the Makefile.
Link: http://lkml.kernel.org/r/1510076320-69931-3-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to make stack-protector failures warn instead of unconditionally
breaking the build, this moves the compiler output sanity-check earlier,
and sets a flag for later testing. Future patches can choose to warn or
fail, depending on the flag value.
Link: http://lkml.kernel.org/r/1510076320-69931-2-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A single character (line break) should be put into a sequence. Thus use
the corresponding function "seq_putc".
This issue was detected by using the Coccinelle software.
Link: http://lkml.kernel.org/r/04fb69fe-d820-9141-820f-07e9a48f4635@users.sourceforge.net
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rearrange args for smaller code.
lookup revolves around memcmp() which gets len 3rd arg, so propagate
length as 3rd arg.
readdir and lookup add additional arg to VFS ->readdir and ->lookup, so
better add it to the end.
Space savings on x86_64:
add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-18 (-18)
Function old new delta
proc_readdir 22 13 -9
proc_lookup 18 9 -9
proc_match() is smaller if not inlined, I promise!
Link: http://lkml.kernel.org/r/20180104175958.GB5204@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
use_pde() is used at every open/read/write/... of every random /proc
file. Negative refcount happens only if PDE is being deleted by module
(read: never). So it gets "likely".
unuse_pde() gets "unlikely" for the same reason.
close_pdeo() gets unlikely as the completion is filled only if there is a
race between PDE removal and close() (read: never ever).
It even saves code on x86_64 defconfig:
add/remove: 0/0 grow/shrink: 1/2 up/down: 2/-20 (-18)
Function old new delta
close_pdeo 183 185 +2
proc_reg_get_unmapped_area 119 111 -8
proc_reg_poll 85 73 -12
Link: http://lkml.kernel.org/r/20180104175657.GA5204@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
/proc/self inode numbers, value of proc_inode_cache and st_nlink of
/proc/$TGID are fixed constants.
Link: http://lkml.kernel.org/r/20180103184707.GA31849@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
struct proc_dir_entry became bit messy over years:
* move 16-bit ->mode_t before namelen to get rid of padding
* make ->in_use first field: it seems to be most used resulting in
smaller code on x86_64 (defconfig):
add/remove: 0/0 grow/shrink: 7/13 up/down: 24/-67 (-43)
Function old new delta
proc_readdir_de 451 455 +4
proc_get_inode 282 286 +4
pde_put 65 69 +4
remove_proc_subtree 294 297 +3
remove_proc_entry 297 300 +3
proc_register 295 298 +3
proc_notify_change 94 97 +3
unuse_pde 27 26 -1
proc_reg_write 89 85 -4
proc_reg_unlocked_ioctl 85 81 -4
proc_reg_read 89 85 -4
proc_reg_llseek 87 83 -4
proc_reg_get_unmapped_area 123 119 -4
proc_entry_rundown 139 135 -4
proc_reg_poll 91 85 -6
proc_reg_mmap 79 73 -6
proc_get_link 55 49 -6
proc_reg_release 108 101 -7
proc_reg_open 298 291 -7
close_pdeo 228 218 -10
* move writeable fields together to a first cacheline (on x86_64),
those include
* ->in_use: reference count, taken every open/read/write/close etc
* ->count: reference count, taken at readdir on every entry
* ->pde_openers: tracks (nearly) every open, dirtied
* ->pde_unload_lock: spinlock protecting ->pde_openers
* ->proc_iops, ->proc_fops, ->data: writeonce fields,
used right together with previous group.
* other rarely written fields go into 1st/2nd and 2nd/3rd cacheline on
32-bit and 64-bit respectively.
Additionally on 32-bit, ->subdir, ->subdir_node, ->namelen, ->name go
fully into 2nd cacheline, separated from writeable fields. They are all
used during lookup.
Link: http://lkml.kernel.org/r/20171220215914.GA7877@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit df04abfd18 ("fs/proc/kcore.c: Add bounce buffer for ktext
data") added a bounce buffer to avoid hardened usercopy checks. Copying
to the bounce buffer was implemented with a simple memcpy() assuming
that it is always valid to read from kernel memory iff the
kern_addr_valid() check passed.
A simple, but pointless, test case like "dd if=/proc/kcore of=/dev/null"
now can easily crash the kernel, since the former execption handling on
invalid kernel addresses now doesn't work anymore.
Also adding a kern_addr_valid() implementation wouldn't help here. Most
architectures simply return 1 here, while a couple implemented a page
table walk to figure out if something is mapped at the address in
question.
With DEBUG_PAGEALLOC active mappings are established and removed all the
time, so that relying on the result of kern_addr_valid() before
executing the memcpy() also doesn't work.
Therefore simply use probe_kernel_read() to copy to the bounce buffer.
This also allows to simplify read_kcore().
At least on s390 this fixes the observed crashes and doesn't introduce
warnings that were removed with df04abfd18 ("fs/proc/kcore.c: Add
bounce buffer for ktext data"), even though the generic
probe_kernel_read() implementation uses uaccess functions.
While looking into this I'm also wondering if kern_addr_valid() could be
completely removed...(?)
Link: http://lkml.kernel.org/r/20171202132739.99971-1-heiko.carstens@de.ibm.com
Fixes: df04abfd18 ("fs/proc/kcore.c: Add bounce buffer for ktext data")
Fixes: f5509cc18d ("mm: Hardened usercopy")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dentry name can be evaluated later, right before calling into VFS.
Also, spend less time under ->mmap_sem.
Link: http://lkml.kernel.org/r/20171110163034.GA2534@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Iterators aren't necessary as you can just grab the first entry and delete
it until no entries left.
Link: http://lkml.kernel.org/r/20171121191121.GA20757@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Current code does:
if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
However sscanf() is broken garbage.
It silently accepts whitespace between format specifiers
(did you know that?).
It silently accepts valid strings which result in integer overflow.
Do not use sscanf() for any even remotely reliable parsing code.
OK
# readlink '/proc/1/map_files/55a23af39000-55a23b05b000'
/lib/systemd/systemd
broken
# readlink '/proc/1/map_files/ 55a23af39000-55a23b05b000'
/lib/systemd/systemd
broken
# readlink '/proc/1/map_files/55a23af39000-55a23b05b000 '
/lib/systemd/systemd
very broken
# readlink '/proc/1/map_files/1000000000000000055a23af39000-55a23b05b000'
/lib/systemd/systemd
Andrei said:
: This patch breaks criu. It was a bug in criu. And this bug is on a minor
: path, which works when memfd_create() isn't available. It is a reason why
: I ask to not backport this patch to stable kernels.
:
: In CRIU this bug can be triggered, only if this patch will be backported
: to a kernel which version is lower than v3.16.
Link: http://lkml.kernel.org/r/20171120212706.GA14325@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
READ_ONCE and WRITE_ONCE are useless when there is only one read/write
is being made.
Link: http://lkml.kernel.org/r/20171120204033.GA9446@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PROC_NUMBUF is 13 which is enough for "negative int + \n + \0".
However PIDs and TGIDs are never negative and newline is not a concern,
so use just 10 per integer.
Link: http://lkml.kernel.org/r/20171120203005.GA27743@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alexander Viro <viro@ftp.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Variable real_size is initialized with a value that is never read, it is
re-assigned a new value later on, hence the initialization is redundant
and can be removed.
Cleans up clang warning:
lib/test_kasan.c:422:21: warning: Value stored to 'real_size' during its initialization is never read
Link: http://lkml.kernel.org/r/20180206144950.32457-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now the fact that KASAN uses a single shadow byte for 8 bytes of
memory is scattered all over the code.
This change defines KASAN_SHADOW_SCALE_SHIFT early in asm include files
and makes use of this constant where necessary.
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/34937ca3b90736eaad91b568edf5684091f662e3.1515775666.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Both of these functions deal with freeing of slab objects.
However, kasan_poison_kfree() mishandles SLAB_TYPESAFE_BY_RCU
(must also not poison such objects) and does not detect double-frees.
Unify code between these functions.
This solves both of the problems and allows to add more common code
(e.g. detection of invalid frees).
Link: http://lkml.kernel.org/r/385493d863acf60408be219a021c3c8e27daa96f.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Detect frees of pointers into middle of mempool objects.
I did a one-off test, but it turned out to be very tricky, so I reverted
it. First, mempool does not call kasan_poison_kfree() unless allocation
function fails. I stubbed an allocation function to fail on second and
subsequent allocations. But then mempool stopped to call
kasan_poison_kfree() at all, because it does it only when allocation
function is mempool_kmalloc(). We could support this special failing
test allocation function in mempool, but it also can't live with kasan
tests, because these are in a module.
Link: http://lkml.kernel.org/r/bf7a7d035d7a5ed62d2dd0e3d2e8a4fcdf456aa7.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__builtin_return_address(1) is unreliable without frame pointers.
With defconfig on kmalloc_pagealloc_invalid_free test I am getting:
BUG: KASAN: double-free or invalid-free in (null)
Pass caller PC from callers explicitly.
Link: http://lkml.kernel.org/r/9b01bc2d237a4df74ff8472a3bf6b7635908de01.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "kasan: detect invalid frees".
KASAN detects double-frees, but does not detect invalid-frees (when a
pointer into a middle of heap object is passed to free). We recently had
a very unpleasant case in crypto code which freed an inner object inside
of a heap allocation. This left unnoticed during free, but totally
corrupted heap and later lead to a bunch of random crashes all over kernel
code.
Detect invalid frees.
This patch (of 5):
Detect frees of pointers into middle of large heap objects.
I dropped const from kasan_kfree_large() because it starts propagating
through a bunch of functions in kasan_report.c, slab/slub nearest_obj(),
all of their local variables, fixup_red_left(), etc.
Link: http://lkml.kernel.org/r/1b45b4fe1d20fc0de1329aab674c1dd973fee723.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As a code-size optimization, LLVM builds since r279383 may bulk-manipulate
the shadow region when (un)poisoning large memory blocks. This requires
new callbacks that simply do an uninstrumented memset().
This fixes linking the Clang-built kernel when using KASAN.
[arnd@arndb.de: add declarations for internal functions]
Link: http://lkml.kernel.org/r/20180105094112.2690475-1-arnd@arndb.de
[fengguang.wu@intel.com: __asan_set_shadow_00 can be static]
Link: http://lkml.kernel.org/r/20171223125943.GA74341@lkp-ib03
[ghackmann@google.com: fix memset() parameters, and tweak commit message to describe new callbacks]
Link: http://lkml.kernel.org/r/20171204191735.132544-6-paullawrence@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
clang's AddressSanitizer implementation adds redzones on either side of
alloca()ed buffers. These redzones are 32-byte aligned and at least 32
bytes long.
__asan_alloca_poison() is passed the size and address of the allocated
buffer, *excluding* the redzones on either side. The left redzone will
always be to the immediate left of this buffer; but AddressSanitizer may
need to add padding between the end of the buffer and the right redzone.
If there are any 8-byte chunks inside this padding, we should poison
those too.
__asan_allocas_unpoison() is just passed the top and bottom of the dynamic
stack area, so unpoisoning is simpler.
Link: http://lkml.kernel.org/r/20171204191735.132544-4-paullawrence@google.com
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
LLVM doesn't understand GCC-style paramters ("--param asan-foo=bar"), thus
we currently we don't use inline/globals/stack instrumentation when
building the kernel with clang.
Add support for LLVM-style parameters ("-mllvm -asan-foo=bar") to enable
all KASAN features.
Link: http://lkml.kernel.org/r/20171204191735.132544-3-paullawrence@google.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "kasan: support alloca, LLVM", v4.
This patch (of 5):
For now we can hard-code ASAN ABI level 5, since historical clang builds
can't build the kernel anyway. We also need to emulate gcc's
__SANITIZE_ADDRESS__ flag, or memset() calls won't be instrumented.
Link: http://lkml.kernel.org/r/20171204191735.132544-2-paullawrence@google.com
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
