kernel/drivers/mtd/ubi/debug.c, branch linux-6.9.y

ubi: Reserve sufficient buffer length for the input mask

2024-01-06T22:45:44Z

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

2024-01-06T22:41:40Z

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

2024-01-06T22:39:29Z

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

2024-01-06T22:38:55Z

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

2023-02-02T20:13:45Z

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

2022-11-18T01:15:15Z

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

2022-10-11T23:42:55Z

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

2021-12-23T19:23:40Z

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

ubifs: fix snprintf() checking

2021-06-18T20:04:47Z

The snprintf() function returns the number of characters (not counting the NUL terminator) that it would have printed if we had space. This buffer has UBIFS_DFS_DIR_LEN characters plus one extra for the terminator. Printing UBIFS_DFS_DIR_LEN is okay but anything higher will result in truncation. Thus the comparison needs to be change from == to >. These strings are compile time constants so this patch doesn't affect runtime. Fixes: ae380ce04731 ("UBIFS: lessen the size of debugging info data structure") Signed-off-by: Dan Carpenter Reviewed-by: Alexander Dahl Signed-off-by: Richard Weinberger

ubi: Fix seq_file usage in detailed_erase_block_info debugfs file

2020-05-17T21:38:21Z

3bfa7e141b0b ("fs/seq_file.c: seq_read(): add info message about buggy .next functions") showed that we don't use seq_file correctly. So make sure that our ->next function always updates the position. Fixes: 7bccd12d27b7 ("ubi: Add debugfs file for tracking PEB state") Signed-off-by: Richard Weinberger