fault-inject: use prandom where cryptographically secure randomness is not needed

Currently get_random*() is used to determine the probability of fault
injection, but cryptographically secure random

fault-inject: use prandom where cryptographically secure randomness is not needed

Currently get_random*() is used to determine the probability of fault
injection, but cryptographically secure random numbers are not required.

There is no big problem in using prandom instead of get_random*() to
determine the probability of fault injection, and it also avoids acquiring
a spinlock, which is unsafe in some contexts.

[[email protected]: tweak and reflow comment]
Link: https://lore.kernel.org/lkml/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Akinobu Mita <[email protected]>
Suggested-by: Peter Zijlstra <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

fault-inject: improve build for CONFIG_FAULT_INJECTION=n

The fault-inject.h users across the kernel need to add a lot of #ifdef
CONFIG_FAULT_INJECTION to cater for shortcomings in the header. Make

fault-inject: improve build for CONFIG_FAULT_INJECTION=n

The fault-inject.h users across the kernel need to add a lot of #ifdef
CONFIG_FAULT_INJECTION to cater for shortcomings in the header. Make
fault-inject.h self-contained for CONFIG_FAULT_INJECTION=n, and add stubs
for DECLARE_FAULT_ATTR(), setup_fault_attr(), should_fail_ex(), and
should_fail() to allow removal of conditional compilation.

[[email protected]: repair fallout from no longer including debugfs.h into fault-inject.h]
[[email protected]: fix drivers/misc/xilinx_tmr_inject.c]
[[email protected]: Add debugfs.h inclusion to more files, per Stephen]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 6ff1cb355e62 ("[PATCH] fault-injection capabilities infrastructure")
Signed-off-by: Jani Nikula <[email protected]>
Cc: Akinobu Mita <[email protected]>
Cc: Abhinav Kumar <[email protected]>
Cc: Dmitry Baryshkov <[email protected]>
Cc: Himal Prasad Ghimiray <[email protected]>
Cc: Lucas De Marchi <[email protected]>
Cc: Rob Clark <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Thomas Hellström <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

fault-inject: allow configuration via configfs

This provides a helper function to allow configuration of fault-injection
for configfs-based drivers.

The config items created by this function have t

fault-inject: allow configuration via configfs

This provides a helper function to allow configuration of fault-injection
for configfs-based drivers.

The config items created by this function have the same interface as the
one created under debugfs by fault_create_debugfs_attr().

Signed-off-by: Akinobu Mita <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

show more ...

fault-injection: make stacktrace filter works as expected

stacktrace filter is checked after others, such as fail-nth, interval and
probability. This make it doesn't work well as expected.

Fix to

fault-injection: make stacktrace filter works as expected

stacktrace filter is checked after others, such as fail-nth, interval and
probability. This make it doesn't work well as expected.

Fix to running stacktrace filter before other filters. It will speed up
fault inject testing for driver modules.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Wei Yongjun <[email protected]>
Cc: Akinobu Mita <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Isabella Basso <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

fault-injection: make some stack filter attrs more readable

Attributes of stack filter are show as unsigned decimal, such as
'require-start', 'require-end'. This patch change to show them as
unsign

fault-injection: make some stack filter attrs more readable

Attributes of stack filter are show as unsigned decimal, such as
'require-start', 'require-end'. This patch change to show them as
unsigned hexadecimal for more readable.

Before:
$ echo 0xffffffffc0257000 > /sys/kernel/debug/failslab/require-start
$ cat /sys/kernel/debug/failslab/require-start
18446744072638263296

After:
$ echo 0xffffffffc0257000 > /sys/kernel/debug/failslab/require-start
$ cat /sys/kernel/debug/failslab/require-start
0xffffffffc0257000

[[email protected]: use debugfs_create_xul() instead of debugfs_create_xl()]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Wei Yongjun <[email protected]>
Signed-off-by: Wang Yufen <[email protected]>
Reviewed-by: Akinobu Mita <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Isabella Basso <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

fault-injection: skip stacktrace filtering by default

If FAULT_INJECTION_STACKTRACE_FILTER is enabled, the depth is default to
32. This means fail_stacktrace() will iter each entry's stacktrace, ev

fault-injection: skip stacktrace filtering by default

If FAULT_INJECTION_STACKTRACE_FILTER is enabled, the depth is default to
32. This means fail_stacktrace() will iter each entry's stacktrace, even
if filter is not configured.

This patch changes to quick return from fail_stacktrace() if stacktrace
filter is not set.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Wei Yongjun <[email protected]>
Cc: Akinobu Mita <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Isabella Basso <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm: fix unexpected changes to {failslab|fail_page_alloc}.attr

When we specify __GFP_NOWARN, we only expect that no warnings will be
issued for current caller. But in the __should_failslab() and
__s

mm: fix unexpected changes to {failslab|fail_page_alloc}.attr

When we specify __GFP_NOWARN, we only expect that no warnings will be
issued for current caller. But in the __should_failslab() and
__should_fail_alloc_page(), the local GFP flags alter the global
{failslab|fail_page_alloc}.attr, which is persistent and shared by all
tasks. This is not what we expected, let's fix it.

[[email protected]: unexport should_fail_ex()]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 3f913fc5f974 ("mm: fix missing handler for __GFP_NOWARN")
Signed-off-by: Qi Zheng <[email protected]>
Reported-by: Dmitry Vyukov <[email protected]>
Reviewed-by: Akinobu Mita <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Cc: Akinobu Mita <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

treewide: use get_random_u32_below() instead of deprecated function

This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
(E)

Reviewed-

treewide: use get_random_u32_below() instead of deprecated function

This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
(E)

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Darrick J. Wong <[email protected]> # for xfs
Reviewed-by: SeongJae Park <[email protected]> # for damon
Reviewed-by: Jason Gunthorpe <[email protected]> # for infiniband
Reviewed-by: Russell King (Oracle) <[email protected]> # for arm
Acked-by: Ulf Hansson <[email protected]> # for mmc
Signed-off-by: Jason A. Donenfeld <[email protected]>

show more ...

treewide: use prandom_u32_max() when possible, part 1

Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
t

treewide: use prandom_u32_max() when possible, part 1

Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:

@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)

@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@

- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);

// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@

((T)get_random_u32()@p & (LITERAL))

// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@

value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))

// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@

- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)

@collapse_ret@
type T;
identifier VAR;
expression E;
@@

{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}

@drop_var@
type T;
identifier VAR;
@@

{
- T VAR;
... when != VAR
}

Reviewed-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Yury Norov <[email protected]>
Reviewed-by: KP Singh <[email protected]>
Reviewed-by: Jan Kara <[email protected]> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <[email protected]> # for drbd
Acked-by: Jakub Kicinski <[email protected]>
Acked-by: Heiko Carstens <[email protected]> # for s390
Acked-by: Ulf Hansson <[email protected]> # for mmc
Acked-by: Darrick J. Wong <[email protected]> # for xfs
Signed-off-by: Jason A. Donenfeld <[email protected]>

show more ...

mm: fix missing handler for __GFP_NOWARN

We expect no warnings to be issued when we specify __GFP_NOWARN, but
currently in paths like alloc_pages() and kmalloc(), there are still some
warnings print

mm: fix missing handler for __GFP_NOWARN

We expect no warnings to be issued when we specify __GFP_NOWARN, but
currently in paths like alloc_pages() and kmalloc(), there are still some
warnings printed, fix it.

But for some warnings that report usage problems, we don't deal with them.
If such warnings are printed, then we should fix the usage problems.
Such as the following case:

WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));

[[email protected]: v2]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Qi Zheng <[email protected]>
Cc: Akinobu Mita <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Steven Rostedt (Google) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

fault_inject: Don't rely on "return value" from WRITE_ONCE()

It's a bit weird that WRITE_ONCE() evaluates to the value it stores and
it's different to smp_store_release(), which can't be used this w

fault_inject: Don't rely on "return value" from WRITE_ONCE()

It's a bit weird that WRITE_ONCE() evaluates to the value it stores and
it's different to smp_store_release(), which can't be used this way.

In preparation for preventing this in WRITE_ONCE(), change the fault
injection code to use a local variable instead.

Cc: Akinobu Mita <[email protected]>
Signed-off-by: Will Deacon <[email protected]>

show more ...

fault-inject: clean up debugfs file creation logic

There is no need to check the return value of a debugfs_create_file
call, a caller should never change what they do depending on if debugfs
is work

fault-inject: clean up debugfs file creation logic

There is no need to check the return value of a debugfs_create_file
call, a caller should never change what they do depending on if debugfs
is working properly or not, so remove the checks, simplifying the logic
in the file a lot.

Also fix up the error check for debugfs_create_dir() which was not
returning NULL for an error, but rather a error pointer.

Cc: [email protected]
Reviewed-by: Akinobu Mita <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

treewide: Add SPDX license identifier for missed files

Add SPDX license identifiers to all files which:

- Have no license information of any form

- Have EXPORT_.*_SYMBOL_GPL inside which was use

treewide: Add SPDX license identifier for missed files

Add SPDX license identifiers to all files which:

- Have no license information of any form

- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

fault-inject: Simplify stacktrace retrieval

Replace the indirection through struct stack_trace with an invocation of
the storage array based interface.

Signed-off-by: Thomas Gleixner <tglx@linutron

fault-inject: Simplify stacktrace retrieval

Replace the indirection through struct stack_trace with an invocation of
the storage array based interface.

Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Josh Poimboeuf <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Akinobu Mita <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: [email protected]
Cc: David Rientjes <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: [email protected]
Cc: Mike Rapoport <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: [email protected]
Cc: Robin Murphy <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Johannes Thumshirn <[email protected]>
Cc: David Sterba <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Mike Snitzer <[email protected]>
Cc: Alasdair Kergon <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: [email protected]
Cc: Joonas Lahtinen <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: [email protected]
Cc: David Airlie <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: Miroslav Benes <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]

show more ...

fault-inject: fix wrong should_fail() decision in task context

Commit 1203c8e6fb0a ("fault-inject: simplify access check for fail-nth")
unintentionally broke a conditional statement in should_fail()

fault-inject: fix wrong should_fail() decision in task context

Commit 1203c8e6fb0a ("fault-inject: simplify access check for fail-nth")
unintentionally broke a conditional statement in should_fail(). Any
faults are not injected in the task context by the change when the
systematic fault injection is not used.

This change restores to the previous correct behaviour.

Link: http://lkml.kernel.org/r/[email protected]
Fixes: 1203c8e6fb0a ("fault-inject: simplify access check for fail-nth")
Signed-off-by: Akinobu Mita <[email protected]>
Reported-by: Lu Fengqi <[email protected]>
Tested-by: Lu Fengqi <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

fault-inject: simplify access check for fail-nth

The fail-nth file is created with 0666 and the access is permitted if
and only if the task is current.

This file is owned by the currnet user. So w

fault-inject: simplify access check for fail-nth

The fail-nth file is created with 0666 and the access is permitted if
and only if the task is current.

This file is owned by the currnet user. So we can create it with 0644
and allow the owner to write it. This enables to watch the status of
task->fail_nth from another processes.

[[email protected]: don't convert unsigned type value as signed int]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: avoid unwanted data race to task->fail_nth]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Akinobu Mita <[email protected]>
Acked-by: Dmitry Vyukov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

fault-inject: support systematic fault injection

Add /proc/self/task/<current-tid>/fail-nth file that allows failing
0-th, 1-st, 2-nd and so on calls systematically.
Excerpt from the added documenta

fault-inject: support systematic fault injection

Add /proc/self/task/<current-tid>/fail-nth file that allows failing
0-th, 1-st, 2-nd and so on calls systematically.
Excerpt from the added documentation:

"Write to this file of integer N makes N-th call in the current task
fail (N is 0-based). Read from this file returns a single char 'Y' or
'N' that says if the fault setup with a previous write to this file
was injected or not, and disables the fault if it wasn't yet injected.
Note that this file enables all types of faults (slab, futex, etc).
This setting takes precedence over all other generic settings like
probability, interval, times, etc. But per-capability settings (e.g.
fail_futex/ignore-private) take precedence over it. This feature is
intended for systematic testing of faults in a single system call. See
an example below"

Why add a new setting:
1. Existing settings are global rather than per-task.
So parallel testing is not possible.
2. attr->interval is close but it depends on attr->count
which is non reset to 0, so interval does not work as expected.
3. Trying to model this with existing settings requires manipulations
of all of probability, interval, times, space, task-filter and
unexposed count and per-task make-it-fail files.
4. Existing settings are per-failure-type, and the set of failure
types is potentially expanding.
5. make-it-fail can't be changed by unprivileged user and aggressive
stress testing better be done from an unprivileged user.
Similarly, this would require opening the debugfs files to the
unprivileged user, as he would need to reopen at least times file
(not possible to pre-open before dropping privs).

The proposed interface solves all of the above (see the example).

We want to integrate this into syzkaller fuzzer. A prototype has found
10 bugs in kernel in first day of usage:

https://groups.google.com/forum/#!searchin/syzkaller/%22FAULT_INJECTION%22%7Csort:relevance

I've made the current interface work with all types of our sandboxes.
For setuid the secret sauce was prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) to
make /proc entries non-root owned. So I am fine with the current
version of the code.

[[email protected]: fix build]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Dmitry Vyukov <[email protected]>
Cc: Akinobu Mita <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

lib/fault-inject.c: use correct check for interrupts

in_interrupt() also returns true when bh is disabled in task context.
That's not what fail_task() wants to check. Use the new in_task()
predicat

lib/fault-inject.c: use correct check for interrupts

in_interrupt() also returns true when bh is disabled in task context.
That's not what fail_task() wants to check. Use the new in_task()
predicate that does the right thing.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Dmitry Vyukov <[email protected]>
Reviewed-by: Akinobu Mita <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

fault-inject: fix inverted interval/probability values in printk

interval displays the probability and vice versa.

Fixes: 6adc4a22f20bb ("fault-inject: add ratelimit option")
Acked-by: Akinobu Mita

fault-inject: fix inverted interval/probability values in printk

interval displays the probability and vice versa.

Fixes: 6adc4a22f20bb ("fault-inject: add ratelimit option")
Acked-by: Akinobu Mita <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

fault-inject: add ratelimit option

Current debug levels are not optimal. Especially if one want to provoke
big numbers of faults(broken device simulator) then any verbose level will
produce giant n

fault-inject: add ratelimit option

Current debug levels are not optimal. Especially if one want to provoke
big numbers of faults(broken device simulator) then any verbose level will
produce giant numbers of identical logging messages. Let's add ratelimit
parameter for that purpose.

Signed-off-by: Dmitry Monakhov <[email protected]>
Acked-by: Akinobu Mita <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

debugfs: add get/set for atomic types

debugfs currently lack the ability to create attributes
that set/get atomic_t values.

This patch adds support for this through a new
debugfs_create_atomic_t()

debugfs: add get/set for atomic types

debugfs currently lack the ability to create attributes
that set/get atomic_t values.

This patch adds support for this through a new
debugfs_create_atomic_t() function.

Signed-off-by: Seth Jennings <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Acked-by: Rik van Riel <[email protected]>
Acked-by: Konrad Rzeszutek Wilk <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

lib/: rename random32() to prandom_u32()

Use preferable function name which implies using a pseudo-random
number generator.

Signed-off-by: Akinobu Mita <[email protected]>
Signed-off-by: Andre

lib/: rename random32() to prandom_u32()

Use preferable function name which implies using a pseudo-random
number generator.

Signed-off-by: Akinobu Mita <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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fault-inject: avoid call to random32() if fault injection is disabled

After enabling CONFIG_FAILSLAB I noticed random32 in profiles even if slub
fault injection wasn't enabled at runtime.

should_fa

fault-inject: avoid call to random32() if fault injection is disabled

After enabling CONFIG_FAILSLAB I noticed random32 in profiles even if slub
fault injection wasn't enabled at runtime.

should_fail forces a comparison against random32() even if probability is
0:

if (attr->probability <= random32() % 100)
return false;

Add a check up front for probability == 0 and avoid all of the more
complicated checks.

Signed-off-by: Anton Blanchard <[email protected]>
Acked-by: Akinobu Mita <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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lib: reduce the use of module.h wherever possible

For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete t

lib: reduce the use of module.h wherever possible

For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include. Fix up any implicit
include dependencies that were being masked by module.h along
the way.

Signed-off-by: Paul Gortmaker <[email protected]>

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switch debugfs to umode_t

Signed-off-by: Al Viro <[email protected]>