kernel/linux.git/drivers/mtd/mtdconcat.c, branch linux-7.1.y

mtd: concat: replace alloc + calloc with 1 alloc

2026-03-11T15:23:57+00:00

A flex array can be used to reduce the allocation to 1. And actually mtdconcat was using the pointer + 1 trick to point to the overallocated area. Better alternatives exist. Signed-off-by: Rosen Penev Signed-off-by: Miquel Raynal

mtd: Move struct mtd_concat definition to header file

2026-02-25T16:34:20+00:00

To enable a more generic approach for concatenating MTD devices, struct mtd_concat should be accessible beyond the mtdconcat driver. Therefore, the definition is being moved to a header file. Signed-off-by: Amit Kumar Mahapatra Signed-off-by: Luca Ceresoli Signed-off-by: Miquel Raynal

Convert more 'alloc_obj' cases to default GFP_KERNEL arguments

2026-02-22T04:03:00+00:00

This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

mtd: concat: Use kmemdup_array instead of kmemdup for multiple allocation

2024-08-23T17:25:51+00:00

When we are allocating an array, using kmemdup_array() to take care about multiplication and possible overflows. Also it makes auditing the code easier. Signed-off-by: Yan Zhen Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20240823110824.3895787-1-yanzhen@vivo.com

mtd: fix repeated word in comment

2022-09-20T08:40:30+00:00

Delete the redundant word 'in'. Signed-off-by: wangjianli Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20220908122229.10814-1-wangjianli@cdjrlc.com

mtd: mtdconcat: Check _read, _write callbacks existence before assignment

2021-08-17T16:43:33+00:00

Since 2431c4f5b46c3 ("mtd: Implement mtd_{read,write}() as wrappers around mtd_{read,write}_oob()") don't allow _write|_read and _write_oob|_read_oob existing at the same time, we should check the existence of callbacks "_read and _write" from subdev's master device (We can trust master device since it has been registered) before assigning, otherwise following warning occurs while making concatenated device: WARNING: CPU: 2 PID: 6728 at drivers/mtd/mtdcore.c:595 add_mtd_device+0x7f/0x7b0 Fixes: 2431c4f5b46c3 ("mtd: Implement mtd_{read,write}() around ...") Signed-off-by: Zhihao Cheng Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20210817114857.2784825-3-chengzhihao1@huawei.com

mtd: mtdconcat: Judge callback existence based on the master

2021-08-17T16:43:30+00:00

Since commit 46b5889cc2c5("mtd: implement proper partition handling") applied, mtd partition device won't hold some callback functions, such as _block_isbad, _block_markbad, etc. Besides, function mtd_block_isbad() will get mtd device's master mtd device, then invokes master mtd device's callback function. So, following process may result mtd_block_isbad() always return 0, even though mtd device has bad blocks: 1. Split a mtd device into 3 partitions: PA, PB, PC [ Each mtd partition device won't has callback function _block_isbad(). ] 2. Concatenate PA and PB as a new mtd device PN [ mtd_concat_create() finds out each subdev has no callback function _block_isbad(), so PN won't be assigned callback function concat_block_isbad(). ] Then, mtd_block_isbad() checks "!master->_block_isbad" is true, will always return 0. Reproducer: // reproduce.c static int __init init_diy_module(void) { struct mtd_info *mtd[2]; struct mtd_info *mtd_combine = NULL; mtd[0] = get_mtd_device_nm("NAND simulator partition 0"); if (!mtd[0]) { pr_err("cannot find mtd1\n"); return -EINVAL; } mtd[1] = get_mtd_device_nm("NAND simulator partition 1"); if (!mtd[1]) { pr_err("cannot find mtd2\n"); return -EINVAL; } put_mtd_device(mtd[0]); put_mtd_device(mtd[1]); mtd_combine = mtd_concat_create(mtd, 2, "Combine mtd"); if (mtd_combine == NULL) { pr_err("combine failed\n"); return -EINVAL; } mtd_device_register(mtd_combine, NULL, 0); pr_info("Combine success\n"); return 0; } 1. ID="0x20,0xac,0x00,0x15" 2. modprobe nandsim id_bytes=$ID parts=50,100 badblocks=100 3. insmod reproduce.ko 4. flash_erase /dev/mtd3 0 0 libmtd: error!: MEMERASE64 ioctl failed for eraseblock 100 (mtd3) error 5 (Input/output error) // Should be "flash_erase: Skipping bad block at 00c80000" Fixes: 46b5889cc2c54bac ("mtd: implement proper partition handling") Signed-off-by: Zhihao Cheng Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20210817114857.2784825-2-chengzhihao1@huawei.com

mtd: mtdconcat: map: remove redundant assignment to variable 'size'

2020-09-11T16:49:34+00:00

Variable 'size' is being assigned the value zero that will never be read. The assignment is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20200910154451.752569-1-colin.king@canonical.com