mm: delete checks for xor_unlock_is_negative_byte()

Architectures which don't define their own use the one in
asm-generic/bitops/lock.h. Get rid of all the ifdefs around "maybe we
don't have it".

mm: delete checks for xor_unlock_is_negative_byte()

Architectures which don't define their own use the one in
asm-generic/bitops/lock.h. Get rid of all the ifdefs around "maybe we
don't have it".

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Andreas Dilger <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: "Theodore Ts'o" <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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bitops: add xor_unlock_is_negative_byte()

Replace clear_bit_and_unlock_is_negative_byte() with
xor_unlock_is_negative_byte(). We have a few places that like to lock a
folio, set a flag and unlock i

bitops: add xor_unlock_is_negative_byte()

Replace clear_bit_and_unlock_is_negative_byte() with
xor_unlock_is_negative_byte(). We have a few places that like to lock a
folio, set a flag and unlock it again. Allow for the possibility of
combining the latter two operations for efficiency. We are guaranteed
that the caller holds the lock, so it is safe to unlock it with the xor.
The caller must guarantee that nobody else will set the flag without
holding the lock; it is not safe to do this with the PG_dirty flag, for
example.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Andreas Dilger <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: "Theodore Ts'o" <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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treewide: use get_random_u32_inclusive() when possible

These cases were done with this Coccinelle:

@@
expression H;
expression L;
@@
- (get_random_u32_below(H) + L)
+ get_random_u32_inclusive(L, H

treewide: use get_random_u32_inclusive() when possible

These cases were done with this Coccinelle:

@@
expression H;
expression L;
@@
- (get_random_u32_below(H) + L)
+ get_random_u32_inclusive(L, H + L - 1)

@@
expression H;
expression L;
expression E;
@@
get_random_u32_inclusive(L,
H
- + E
- - E
)

@@
expression H;
expression L;
expression E;
@@
get_random_u32_inclusive(L,
H
- - E
- + E
)

@@
expression H;
expression L;
expression E;
expression F;
@@
get_random_u32_inclusive(L,
H
- - E
+ F
- + E
)

@@
expression H;
expression L;
expression E;
expression F;
@@
get_random_u32_inclusive(L,
H
- + E
+ F
- - E
)

And then subsequently cleaned up by hand, with several automatic cases
rejected if it didn't make sense contextually.

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]> # for infiniband
Signed-off-by: Jason A. Donenfeld <[email protected]>

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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]>

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kcsan: remove rng selftest

The first test of the kcsan selftest appears to test if get_random_u32()
returns two zeros in a row, and requires that it doesn't. This seems
like a bogus criteron. Remove

kcsan: remove rng selftest

The first test of the kcsan selftest appears to test if get_random_u32()
returns two zeros in a row, and requires that it doesn't. This seems
like a bogus criteron. Remove it.

Acked-by: Marco Elver <[email protected]>
Signed-off-by: Jason A. Donenfeld <[email protected]>

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treewide: use get_random_bytes() when possible

The prandom_bytes() function has been a deprecated inline wrapper around
get_random_bytes() for several releases now, and compiles down to the
exact sa

treewide: use get_random_bytes() when possible

The prandom_bytes() function has been a deprecated inline wrapper around
get_random_bytes() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. This was done as a basic find and replace.

Reviewed-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Yury Norov <[email protected]>
Reviewed-by: Christophe Leroy <[email protected]> # powerpc
Acked-by: Jakub Kicinski <[email protected]>
Signed-off-by: Jason A. Donenfeld <[email protected]>

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treewide: use get_random_u32() when possible

The prandom_u32() function has been a deprecated inline wrapper around
get_random_u32() for several releases now, and compiles down to the
exact same cod

treewide: use get_random_u32() when possible

The prandom_u32() function has been a deprecated inline wrapper around
get_random_u32() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. The same also applies to get_random_int(), which is
just a wrapper around get_random_u32(). This was done as a basic find
and replace.

Reviewed-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Yury Norov <[email protected]>
Reviewed-by: Jan Kara <[email protected]> # for ext4
Acked-by: Toke Høiland-Jørgensen <[email protected]> # for sch_cake
Acked-by: Chuck Lever <[email protected]> # for nfsd
Acked-by: Jakub Kicinski <[email protected]>
Acked-by: Mika Westerberg <[email protected]> # for thunderbolt
Acked-by: Darrick J. Wong <[email protected]> # for xfs
Acked-by: Helge Deller <[email protected]> # for parisc
Acked-by: Heiko Carstens <[email protected]> # for s390
Signed-off-by: Jason A. Donenfeld <[email protected]>

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kcsan: Only test clear_bit_unlock_is_negative_byte if arch defines it

Some architectures do not define clear_bit_unlock_is_negative_byte().
Only test it when it is actually defined (similar to other

kcsan: Only test clear_bit_unlock_is_negative_byte if arch defines it

Some architectures do not define clear_bit_unlock_is_negative_byte().
Only test it when it is actually defined (similar to other usage, such
as in lib/test_kasan.c).

Link: https://lkml.kernel.org/r/[email protected]
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Marco Elver <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

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kcsan: Make barrier tests compatible with lockdep

The barrier tests in selftest and the kcsan_test module only need the
spinlock and mutex to test correct barrier instrumentation. Therefore,
these w

kcsan: Make barrier tests compatible with lockdep

The barrier tests in selftest and the kcsan_test module only need the
spinlock and mutex to test correct barrier instrumentation. Therefore,
these were initially placed on the stack.

However, lockdep asserts that locks are in static storage, and will
generate this warning:

| INFO: trying to register non-static key.
| The code is fine but needs lockdep annotation, or maybe
| you didn't initialize this object before use?
| turning off the locking correctness validator.
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.16.0-rc1+ #3208
| Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
| Call Trace:
| <TASK>
| dump_stack_lvl+0x88/0xd8
| dump_stack+0x15/0x1b
| register_lock_class+0x6b3/0x840
| ...
| test_barrier+0x490/0x14c7
| kcsan_selftest+0x47/0xa0
| ...

To fix, move the test locks into static storage.

Fixing the above also revealed that lock operations are strengthened on
first use with lockdep enabled, due to lockdep calling out into
non-instrumented files (recall that kernel/locking/lockdep.c is not
instrumented with KCSAN).

Only kcsan_test checks for over-instrumentation of *_lock() operations,
where we can simply "warm up" the test locks to avoid the test case
failing with lockdep.

Reported-by: Paul E. McKenney <[email protected]>
Signed-off-by: Marco Elver <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

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kcsan: selftest: Add test case to check memory barrier instrumentation

Memory barrier instrumentation is crucial to avoid false positives. To
avoid surprises, run a simple test case in the boot-time

kcsan: selftest: Add test case to check memory barrier instrumentation

Memory barrier instrumentation is crucial to avoid false positives. To
avoid surprises, run a simple test case in the boot-time selftest to
ensure memory barriers are still instrumented correctly.

Signed-off-by: Marco Elver <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

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kcsan: selftest: Cleanup and add missing __init

Make test_encode_decode() more readable and add missing __init.

Signed-off-by: Marco Elver <[email protected]>
Signed-off-by: Paul E. McKenney <paulmc

kcsan: selftest: Cleanup and add missing __init

Make test_encode_decode() more readable and add missing __init.

Signed-off-by: Marco Elver <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

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kcsan: Add missing license and copyright headers

Adds missing license and/or copyright headers for KCSAN source files.

Signed-off-by: Marco Elver <[email protected]>
Signed-off-by: Paul E. McKenney

kcsan: Add missing license and copyright headers

Adds missing license and/or copyright headers for KCSAN source files.

Signed-off-by: Marco Elver <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

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kcsan: selftest: Ensure that address is at least PAGE_SIZE

In preparation of supporting only addresses not within the NULL page,
change the selftest to never use addresses that are less than PAGE_SI

kcsan: selftest: Ensure that address is at least PAGE_SIZE

In preparation of supporting only addresses not within the NULL page,
change the selftest to never use addresses that are less than PAGE_SIZE.

Reviewed-by: Dmitry Vyukov <[email protected]>
Signed-off-by: Marco Elver <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

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kcsan: Use pr_fmt for consistency

Use the same pr_fmt throughout for consistency. [ The only exception is
report.c, where the format must be kept precisely as-is. ]

Signed-off-by: Marco Elver <elve

kcsan: Use pr_fmt for consistency

Use the same pr_fmt throughout for consistency. [ The only exception is
report.c, where the format must be kept precisely as-is. ]

Signed-off-by: Marco Elver <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

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kcsan: Rename test.c to selftest.c

Rename 'test.c' to 'selftest.c' to better reflect its purpose (Kconfig
variable and code inside already match this). This is to avoid confusion
with the test suite

kcsan: Rename test.c to selftest.c

Rename 'test.c' to 'selftest.c' to better reflect its purpose (Kconfig
variable and code inside already match this). This is to avoid confusion
with the test suite module in 'kcsan-test.c'.

No functional change.

Signed-off-by: Marco Elver <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

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