kernel/linux.git/drivers/mtd/ubi/debug.c, branch v6.12.80

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43+00:00

no_llseek had been defined to NULL two years ago, in commit 868941b14441 ("fs: remove no_llseek") To quote that commit, At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\/d' $i done would do it. Unfortunately, that hadn't been done. Linus, could you do that now, so that we could finally put that thing to rest? All instances are of the form .llseek = no_llseek, so it's obviously safe. Signed-off-by: Al Viro Signed-off-by: Linus Torvalds

ubifs: correct UBIFS_DFS_DIR_LEN macro definition and improve code clarity

2024-07-12T19:52:24+00:00

The UBIFS_DFS_DIR_LEN macro, which defines the maximum length of the UBIFS debugfs directory name, has an incorrect formula and misleading comments. The current formula is (3 + 1 + 2*2 + 1), which assumes that both UBI device number and volume ID are limited to 2 characters. However, UBI device number ranges from 0 to 31 (2 characters), and volume ID ranges from 0 to 127 (up to 3 characters). Although the current code works due to the cancellation of mathematical errors (9 + 1 = 10, which matches the correct UBIFS_DFS_DIR_LEN value), it can lead to confusion and potential issues in the future. This patch aims to improve the code clarity and maintainability by making the following changes: 1. Corrects the UBIFS_DFS_DIR_LEN macro definition to (3 + 1 + 2 + 3 + 1), accommodating the maximum lengths of both UBI device number and volume ID, plus the separators and null terminator. 2. Updates the snprintf calls to use UBIFS_DFS_DIR_LEN instead of UBIFS_DFS_DIR_LEN + 1, removing the unnecessary +1. 3. Modifies the error checks to compare against UBIFS_DFS_DIR_LEN using >= instead of >, aligning with the corrected macro definition. 4. Removes the redundant +1 in the dfs_dir_name array definitions in ubi.h and debug.h. While these changes do not affect the runtime behavior, they make the code more readable, maintainable, and less prone to future errors. v2->v3: - Removes the duplicated UBIFS_DFS_DIR_LEN and UBIFS_DFS_DIR_NAME macro definitions in ubifs.h, as they are already defined in debug.h. Signed-off-by: ZhaoLong Wang Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: Reserve sufficient buffer length for the input mask

2024-01-06T22:45:44+00:00

Because the mask received by the emulate_failures interface is a 32-bit unsigned integer, ensure that there is sufficient buffer length to receive and display this value. Signed-off-by: ZhaoLong Wang Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: Add six fault injection type for testing

2024-01-06T22:41:40+00:00

This commit adds six fault injection type for testing to cover the abnormal path of the UBI driver. Inject the following faults when the UBI reads the LEB: +----------------------------+-----------------------------------+ | Interface name | emulate behavior | +----------------------------+-----------------------------------+ | emulate_eccerr | ECC error | +----------------------------+-----------------------------------+ | emulate_read_failure | read failure | |----------------------------+-----------------------------------+ | emulate_io_ff | read content as all FF | |----------------------------+-----------------------------------+ | emulate_io_ff_bitflips | content FF with MTD err reported | +----------------------------+-----------------------------------+ | emulate_bad_hdr | bad leb header | |----------------------------+-----------------------------------+ | emulate_bad_hdr_ebadmsg | bad header with ECC err | +----------------------------+-----------------------------------+ Signed-off-by: ZhaoLong Wang Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: Split io_failures into write_failure and erase_failure

2024-01-06T22:39:29+00:00

The emulate_io_failures debugfs entry controls both write failure and erase failure. This patch split io_failures to write_failure and erase_failure. Signed-off-by: ZhaoLong Wang Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: Use the fault injection framework to enhance the fault injection capability

2024-01-06T22:38:55+00:00

To make debug parameters configurable at run time, use the fault injection framework to reconstruct the debugfs interface, and retain the legacy fault injection interface. Now, the file emulate_failures and fault_attr files control whether to enable fault emmulation. The file emulate_failures receives a mask that controls type and process of fault injection. Generally, for ease of use, you can directly enter a mask with all 1s. echo 0xffff > /sys/kernel/debug/ubi/ubi0/emulate_failures And you need to configure other fault-injection capabilities for testing purpose: echo 100 > /sys/kernel/debug/ubi/fault_inject/emulate_power_cut/probability echo 15 > /sys/kernel/debug/ubi/fault_inject/emulate_power_cut/space echo 2 > /sys/kernel/debug/ubi/fault_inject/emulate_power_cut/verbose echo -1 > /sys/kernel/debug/ubi/fault_inject/emulate_power_cut/times The CONFIG_MTD_UBI_FAULT_INJECTION to enable the Fault Injection is added to kconfig. Signed-off-by: ZhaoLong Wang Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: Fix permission display of the debugfs files

2023-02-02T20:13:45+00:00

Some interface files in debugfs support the read method dfs_file_read(), but their rwx permissions is shown as unreadable. In the user mode, the following problem can be clearly seen: # ls -l /sys/kernel/debug/ubi/ubi0/ total 0 --w------- 1 root root 0 Oct 22 16:26 chk_fastmap --w------- 1 root root 0 Oct 22 16:26 chk_gen --w------- 1 root root 0 Oct 22 16:26 chk_io -r-------- 1 root root 0 Oct 22 16:26 detailed_erase_block_info --w------- 1 root root 0 Oct 22 16:26 tst_disable_bgt --w------- 1 root root 0 Oct 22 16:26 tst_emulate_bitflips --w------- 1 root root 0 Oct 22 16:26 tst_emulate_io_failures --w------- 1 root root 0 Oct 22 16:26 tst_emulate_power_cut --w------- 1 root root 0 Oct 22 16:26 tst_emulate_power_cut_max --w------- 1 root root 0 Oct 22 16:26 tst_emulate_power_cut_min It shows that these files do not have read permission 'r', but we can actually read their contents. # echo 1 > /sys/kernel/debug/ubi/ubi0/chk_io # cat /sys/kernel/debug/ubi/ubi0/chk_io 1 User's permission access is determined by capabilities. Of course, the root user is not restricted from reading these files. When reading a debugfs file, the process is as follows: ksys_read() vfs_read() if (file->f_op->read) file->f_op->read() full_proxy_open() real_fops->read() dfs_file_read() -- Read method of debugfs file. else if (file->f_op->read_iter) new_sync_read() else ret = -EINVAL -- Return -EINVAL if no read method. This indicates that the debugfs file can be read as long as the read method of the debugfs file is registered. This patch adds the read permission display for file that support the read method. Signed-off-by: ZhaoLong Wang Signed-off-by: Richard Weinberger

treewide: use get_random_u32_below() instead of deprecated function

2022-11-18T01:15:15+00:00

This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook Reviewed-by: Greg Kroah-Hartman Acked-by: Darrick J. Wong # for xfs Reviewed-by: SeongJae Park # for damon Reviewed-by: Jason Gunthorpe # for infiniband Reviewed-by: Russell King (Oracle) # for arm Acked-by: Ulf Hansson # for mmc Signed-off-by: Jason A. Donenfeld

treewide: use prandom_u32_max() when possible, part 1

2022-10-11T23:42:55+00:00

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

ubi: Fix a mistake in comment

2021-12-23T19:23:40+00:00

Fixes: 2a734bb8d502 ("UBI: use debugfs for the extra checks knobs") There is a mistake in docstrings, it should be ubi_debugfs_exit_dev instead of dbg_debug_exit_dev. Signed-off-by: Kai Song Signed-off-by: Richard Weinberger