mtd: always initialize 'stats' in struct mtd_oob_ops

As the 'stats' field in struct mtd_oob_ops is used in conditional
expressions, ensure it is always zero-initialized in all such structures
to prevent random stack garbage from being interpreted as a pointer.

Strictly speaking, this problem currently only needs to be fixed for
struct mtd_oob_ops structures subsequently passed to mtd_read_oob().
However, this commit goes a step further and makes all instances of
struct mtd_oob_ops in the tree zero-initialized, in hope of preventing
future problems, e.g. if struct mtd_req_stats gets extended with write
statistics at some point.

Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220629125737.14418-3-kernel@kempniu.pl

mtd: mtd_oobtest: Remove redundant assignment to err

Variable err is set to zero but this value is never read as it is
overwritten with a new value later on, hence it is a redundant
assignment and can be removed.

Cleans up the following clang-analyzer warning:

drivers/mtd/tests/oobtest.c:626:4: warning: Value stored to 'err' is
never read [clang-analyzer-deadcode.DeadStores].

drivers/mtd/tests/oobtest.c:603:4: warning: Value stored to 'err' is
never read [clang-analyzer-deadcode.DeadStores].

drivers/mtd/tests/oobtest.c:579:4: warning: Value stored to 'err' is
never read [clang-analyzer-deadcode.DeadStores].

drivers/mtd/tests/oobtest.c:556:4: warning: Value stored to 'err' is
never read [clang-analyzer-deadcode.DeadStores].

drivers/mtd/tests/oobtest.c:532:3: warning: Value stored to 'err' is
never read [clang-analyzer-deadcode.DeadStores].

drivers/mtd/tests/oobtest.c:509:3: warning: Value stored to 'err' is
never read [clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/1619346498-43617-1-git-send-email-jiapeng.chong@linux.alibaba.com

mtd: mtd_oobtest: fix error return code in mtd_oobtest_init()

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210409010739.1021001-1-zhangxiaoxu5@huawei.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 326

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program see the file copying if not
write to the free software foundation 59 temple place suite 330
boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 9 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000435.832876118@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mtd: mtd_oobtest: Handle bitflips during reads

Reads from NAND devices usually trigger bitflips, this is an expected
behavior. While bitflips are under a given threshold, the MTD core
returns 0. However, when the number of corrected bitflips is above this
same threshold, -EUCLEAN is returned to inform the upper layer that this
block is slightly dying and soon the ECC engine will be overtaken so
actions should be taken to move the data out of it.

This particular condition should not be treated like an error and the
test should continue.

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

mtd: kill the ecclayout->oobavail field

ecclayout->oobavail is just redundant with the mtd->oobavail field.
Moreover, it prevents static const definition of ecc layouts since the
NAND framework is calculating this value based on the ecclayout->oobfree
field.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: mtd_oobtest: Fix the address offset with vary_offset case

When vary_offset is set (e.g. test case 3), the offset is not always
zero so memcmpshow() will show the wrong offset in the print message.
To fix this we introduce a new function memcmpshowoffset() which takes
offset as a parameter and displays the right offset and use it in
the case where offset is non zero.

The old memcmpshow() functionality is preserved by converting it into
a macro with offset preset to 0.

Signed-off-by: Roger Quadros <rogerq@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: mtd_oobtest: Fix bitflip_limit usage in test case 3

In test case 3, we set vary_offset to write at different
offsets and lengths in the OOB available area. We need to
do the bitflip_limit check while checking for 0xff outside the
OOB offset + length area that we didn't modify during write.

Signed-off-by: Roger Quadros <rogerq@ti.com>
[Brian: whitespace fixup]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: tests: fix more potential integer overflows

Caught by Coverity (CID #200625 and others)

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>

mtd: oobtest: correct printf() format specifier for 'size_t'

Fixes warning:

drivers/mtd/tests/oobtest.c: In function 'memcmpshow':
drivers/mtd/tests/oobtest.c:129: warning: format '%x' expects type 'unsigned int', but argument 3 has type 'size_t'

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Roger Quadros <rogerq@ti.com>
Cc: Sekhar Nori <nsekhar@ti.com>

mtd: mtd_oobtest: add bitflip_limit parameter

It is common for NAND devices to have bitflip errors.
Add a bitflip_limit parameter to specify how many bitflips per
page we can tolerate without flagging an error.
By default zero bitflips are tolerated.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: mtd_oobtest: Show the verification error location and data

Add a function memcmpshow() that compares the 2 data buffers
and shows the address:offset and data bytes on comparison failure.
This function does not break at a comparison failure but runs the
check for the whole data buffer.

Use memcmpshow() instead of memcmp() for all the verification paths.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: tests: fix integer overflow issues

These multiplications are done with 32-bit arithmetic, then converted to
64-bit. We should widen the integers first to prevent overflow. This
could be a problem for large (>4GB) MTD's.

Detected by Coverity.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>

mtd: mtd_oobtest: generate consistent data for verification

mtd_oobtest writes OOB, read it back and verify. The verification is
not correctly done if oobsize is not multiple of 4. Although the data
to be written and the data to be compared are generated by several
prandom_byte_state() calls starting with the same seed, these two are
generated with the different size and different number of calls.

Due to the implementation of prandom_byte_state() if the size on each
call is not multiple of 4, the resulting data is not always same.

This fixes it by just calling prandom_byte_state() once and using
correct range instead of calling it multiple times for each.

Reported-by: George Cherian <george.cherian@ti.com>
Reported-by: Lothar Waßmann <LW@KARO-electronics.de>
Tested-by: Lothar Waßmann <LW@KARO-electronics.de>
Cc: George Cherian <george.cherian@ti.com>
Cc: Lothar Waßmann <LW@KARO-electronics.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: nand: add a helper to detect the nand type

This helper detects that whether the mtd's type is nand type.

Now, it's clear that the MTD_NANDFLASH stands for SLC nand only.
So use the mtd_type_is_nand() to replace the old check method
to do the nand type (include the SLC and MLC) check.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd: mtd_oobtest: use mtd_test helpers

Use mtdtest_scan_for_bad_eraseblocks(), mtdtest_erase_good_eraseblocks(),
and mtdtest_erase_eraseblock() in mtd_test helpers.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

mtd: tests: rename sources in order to link a helper object

Each mtd test module have a single source whose name is the same as
the module name. In order to link a single object including helper
functions to every test module, this rename these sources to the
different names.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>