kernel/linux.git/drivers/mtd/ubi/debug.c, branch v6.6.132

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

ubifs: fix snprintf() checking

2021-06-18T20:04:47+00:00

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

2020-05-17T21:38:21+00:00

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

Merge tag 'upstream-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs

2019-12-03T01:06:34+00:00

Pull UBI/UBIFS/JFFS2 updates from Richard Weinberger: "This pull request contains mostly fixes for UBI, UBIFS and JFFS2: UBI: - Fix a regression around producing a anchor PEB for fastmap. Due to a change in our locking fastmap was unable to produce fresh anchors an re-used the existing one a way to often. UBIFS: - Fixes for endianness. A few places blindly assumed little endian. - Fix for a memory leak in the orphan code. - Fix for a possible crash during a commit. - Revert a wrong bugfix. JFFS2: - Revert a bad bugfix (false positive from a code checking tool)" * tag 'upstream-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs: Revert "jffs2: Fix possible null-pointer dereferences in jffs2_add_frag_to_fragtree()" ubi: Fix producing anchor PEBs ubifs: ubifs_tnc_start_commit: Fix OOB in layout_in_gaps ubifs: do_kill_orphans: Fix a memory leak bug Revert "ubifs: Fix memory leak bug in alloc_ubifs_info() error path" ubifs: Fix type of sup->hash_algo ubifs: Fixed missed le64_to_cpu() in journal ubifs: Force prandom result to __le32 ubifs: Remove obsolete TODO from dfs_file_write() ubi: Fix warning static is not at beginning of declaration ubi: Print skip_check in ubi_dump_vol_info()

ubi: Print skip_check in ubi_dump_vol_info()

2019-11-17T20:20:53+00:00

It might be interesting, if "skip_check" is set or not, so lets print this flag in ubi_dump_vol_info() as well. Signed-off-by: Stefan Roese Cc: Richard Weinberger Cc: Boris Brezillon Cc: Heiko Schocher Signed-off-by: Richard Weinberger

mtd: no need to check return value of debugfs_create functions

2019-11-14T09:57:38+00:00

When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Cc: David Woodhouse Cc: Brian Norris Cc: Marek Vasut Cc: Miquel Raynal Cc: Richard Weinberger Cc: Vignesh Raghavendra Cc: Artem Bityutskiy Cc: linux-mtd@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Miquel Raynal

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

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 as published by the free software foundation either version 2 of the license or at your option any later version 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 if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman