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 <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

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 <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> # powerpc
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

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 <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

mtd: nand: ecc-hamming: Rename the exported functions

Prefix by ecc_sw_hamming_ the functions which should be internal only
but are exported for "raw" operations.

Prefix by nand_ecc_sw_hamming_ the other functions which will be used
in the context of the declaration of an Hamming proper ECC engine
object.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200929230124.31491-16-miquel.raynal@bootlin.com

mtd: nand: ecc-hamming: Move Hamming code to the generic NAND layer

Hamming ECC code might be later re-used by the SPI NAND layer.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200929230124.31491-12-miquel.raynal@bootlin.com

treewide: Add SPDX license identifier for more missed files

Add SPDX license identifiers to all files which:

- Have no license information of any form

- Have MODULE_LICENCE("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 <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mtd: rawnand: Clarify Kconfig entry MTD_NAND

MTD_NAND is large and encloses much more than what the symbol is
actually used for: raw NAND. Clarify the symbol by naming it
MTD_RAW_NAND instead.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: nand: Clarify Kconfig entry for software Hamming ECC entries

The software Hamming ECC correction implementation is referred as
MTD_NAND_ECC which is too generic. Rename it
MTD_NAND_ECC_SW_HAMMING. Also rename MTD_NAND_ECC_SMC which is an
SMC quirk in the Hamming implementation as
MTD_NAND_ECC_SW_HAMMING_SMC.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Allow selection of ECC byte ordering at runtime

Currently, the selection of ECC byte ordering for software hamming is
done at compilation time, which doesn't make sense when ECC byte
calculation is done in hardware and byte ordering is forced by the
hardware engine.
In this case, only the correction is done in software and we want to
force the byte-ordering no matter the value of CONFIG_MTD_NAND_ECC_SMC.

This is typically the case for the FSMC (Smart Media ordering), TMIO and
TXX9NDFMC (regular byte ordering) blocks.

For all other use cases (pure software implementation, SM FTL and
nandecctest), we keep selecting the byte ordering based on the
CONFIG_MTD_NAND_ECC_SMC value. It might not be ideal for SM FTL (I'd
expect Smart Media ordering to be employed by the Smart Media FTL), but
this option doesn't seem to be enabled in the existing _defconfig, so
I can't tell setting sm_order to true is the right choice.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: nand: tests: fix regression introduced in mtd_nandectest

Offending Commit: 6e94119 "mtd: nand: return consistent error codes in
ecc.correct() implementations"

The new error code was not being handled properly in double bit error
detection.

Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Franklin S Cooper Jr <fcooper@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: Make MTD tests cancelable

I always go nuts when I start an MTD test on a slow device and have to
wait forever until it finishes. From the debug output I already know
what the issue is but I have to wait or reset the board hard. Resetting
is often not an option (remote access, you don't want lose the current
state, etc...).

The solution is easy, check for pending signals at key positions in the
code. Using that one can even stop a test by pressing CTRL-C as
insmod/modprobe have SIGINT pending.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: tests: mtd_nandecctest: Use IS_ENABLED() macro

Using the IS_ENABLED() macro can make the code shorter and simpler.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: mtd_nandecctest: use prandom_bytes instead of get_random_bytes()

Using prandom_bytes() is enough. Because this data is only used
for testing, not used for cryptographic use.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Laight <david.laight@aculab.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Robert Love <robert.w.love@intel.com>
Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mtd: rename random32() to prandom_u32()

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

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

mtd: tests: mtd_nandecctest: Use pr_fmt macro

Use KBUILD_MODNAME instead of hardcoding the filename

Signed-off-by: Vikram Narayanan <vikram186@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

mtd: mtd_nandecctest: add double bit error detection tests

This adds the double bit error detection test cases listed below:

* Prepare data block with double bit error and ECC data without
corruption, and verify that the uncorrectable error is detected by
__nand_correct_data().

* Prepare data block with single bit error and ECC data with single bit
error, and verify that the uncorrectable error is detected.

* Prepare data block without corruption and ECC data with double bit
error, and verify that the uncorrectable error is detected.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtd_nandecctest: add single bit error correction test

This adds the single bit error correction test case listed below:

Prepare data block without corruption and ECC data with single bit error,
and verify that the data block is preserved by __nand_correct_data().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtd_nandecctest: add no corruption test

This adds no corruptin test case listed below:

Prepare data block and ECC data with no corruption, and verify that
the data block is preserved by __nand_correct_data()

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtd_nandecctest: rewrite the test routine

This rewrites the entire test routine in order to make it easy to add more
tests by later changes and minimize duplication of each tests as much as
possible.

Now that each test is described by the members of struct nand_ecc_test:
- name: descriptive testname
- prepare: function to prepare data block and ecc with artifical corruption
- verify: function to verify the result of correcting data block

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtd_nandecctest: support injecting bit error for ecc code

Currently inject_single_bit_error() is used to inject single bit error
into randomly selected bit position of the 256 or 512 bytes data block.

Later change will add tests which inject bit errors into the ecc code.
Unfortunately, inject_single_bit_error() doesn't work for the ecc code
which is not a multiple of sizeof(unsigned long).

Because bit fliping at random position is done by __change_bit().
For example, flipping bit position 0 by __change_bit(0, addr) modifies
3rd byte (32bit) or 7th byte (64bit) on big-endian systems.

Using little-endian version of bitops can fix this issue. But
little-endian version of __change_bit is not yet available.
So this defines __change_bit_le() locally in a similar fashion to
asm-generic/bitops/le.h and use it.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtd_nandecctest: ensure alignment requirement for bitops

Currently the data blocks which is used to test single bit error
correction is allocated statically and injecting single bit error is
implemented by using __change_bit() which must operate on the memory
aligned to the size of an "unsigned long". But there is no such
guarantee for statically allocated array.

This fix the issue by allocating the data block dynamically by
kmalloc(). It also allocate the ecc code dynamically instead of
allocating statically on stack.

The reason to allocate the ecc code dynamically is that later change
will add tests which inject bit errors into the ecc code by bitops.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtd_nandecctest: improve message output

This includes the message related changes:

- Use pr_* instead of printk
- Print hexdump of ECC code if test fails
- Change log level for hexdump of data from KERN_DEBUG to KERN_INFO
- Factor out the hexdump code into a separate function

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtd_nandecctest: make module_init() return appropriate errno

Return -EINVAL instead of -1 (-EPERM) when test fails.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtd_nandecctest: remove unnecessary include

Including linux/jiffies.h was required for calling srandom32(jiffies)
that has already been removed.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtd_nandecctest: make module_init() return an error code if test fails

Return an error code if test fails in order to detect a test case failure
by invoking tests repeatedly like this:

while sudo modprobe mtd_nandecctest; do
sudo modprobe -r mtd_nandecctest
done

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: mtd_nandecctest: remove unnecessary srandom32() call

It is unnecessary for this driver to call srandom32() in module_init.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

mtd: add nand_ecc test module

This module tests NAND ECC functions.

The test is simple.

1. Create a 256 or 512 bytes block of data filled with random bytes (data)
2. Duplicate the data block and inject single bit error (error_data)
3. Try to correct error_data
4. Compare data and error_data

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>