linux-dev/drivers/mtd/ubi, branch master

Merge tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random

2022-10-16T22:27:07Z

Pull more random number generator updates from Jason Donenfeld: "This time with some large scale treewide cleanups. The intent of this pull is to clean up the way callers fetch random integers. The current rules for doing this right are: - If you want a secure or an insecure random u64, use get_random_u64() - If you want a secure or an insecure random u32, use get_random_u32() The old function prandom_u32() has been deprecated for a while now and is just a wrapper around get_random_u32(). Same for get_random_int(). - If you want a secure or an insecure random u16, use get_random_u16() - If you want a secure or an insecure random u8, use get_random_u8() - If you want secure or insecure random bytes, use get_random_bytes(). The old function prandom_bytes() has been deprecated for a while now and has long been a wrapper around get_random_bytes() - If you want a non-uniform random u32, u16, or u8 bounded by a certain open interval maximum, use prandom_u32_max() I say "non-uniform", because it doesn't do any rejection sampling or divisions. Hence, it stays within the prandom_*() namespace, not the get_random_*() namespace. I'm currently investigating a "uniform" function for 6.2. We'll see what comes of that. By applying these rules uniformly, we get several benefits: - By using prandom_u32_max() with an upper-bound that the compiler can prove at compile-time is ≤65536 or ≤256, internally get_random_u16() or get_random_u8() is used, which wastes fewer batched random bytes, and hence has higher throughput. - By using prandom_u32_max() instead of %, when the upper-bound is not a constant, division is still avoided, because prandom_u32_max() uses a faster multiplication-based trick instead. - By using get_random_u16() or get_random_u8() in cases where the return value is intended to indeed be a u16 or a u8, we waste fewer batched random bytes, and hence have higher throughput. This series was originally done by hand while I was on an airplane without Internet. Later, Kees and I worked on retroactively figuring out what could be done with Coccinelle and what had to be done manually, and then we split things up based on that. So while this touches a lot of files, the actual amount of code that's hand fiddled is comfortably small" * tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: prandom: remove unused functions treewide: use get_random_bytes() when possible treewide: use get_random_u32() when possible treewide: use get_random_{u8,u16}() when possible, part 2 treewide: use get_random_{u8,u16}() when possible, part 1 treewide: use prandom_u32_max() when possible, part 2 treewide: use prandom_u32_max() when possible, part 1

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: fastmap: Add fastmap control support for 'UBI_IOCATT' ioctl

2022-09-21T16:29:18Z

[1] suggests that fastmap is suitable for large flash devices. Module parameter 'fm_autoconvert' is a coarse grained switch to enable all ubi devices to generate fastmap, which may turn on fastmap even for small flash devices. This patch imports a new field 'disable_fm' in struct 'ubi_attach_req' to support following situations by ioctl 'UBI_IOCATT'. [old functions] A. Disable 'fm_autoconvert': Disbable fastmap for all ubi devices B. Enable 'fm_autoconvert': Enable fastmap for all ubi devices [new function] C. Enable 'fm_autoconvert', set 'disable_fm' for given device: Don't create new fastmap and do full scan (existed fastmap will be destroyed) for the given ubi device. A simple test case in [2]. [1] http://www.linux-mtd.infradead.org/doc/ubi.html#L_fastmap [2] https://bugzilla.kernel.org/show_bug.cgi?id=216278 Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: fastmap: Use the bitmap API to allocate bitmaps

2022-09-21T09:32:58Z

Use bitmap_zalloc()/bitmap_free() instead of hand-writing them. It is less verbose and it improves the semantic. Signed-off-by: Christophe JAILLET Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger

mtd: ubi: drop unexpected word 'a' in comments

2022-09-21T09:32:38Z

there is an unexpected word 'a' in the comments that need to be dropped file - drivers/mtd/ubi/vmt.c line - 626,779 * Returns zero if volume is all right and a a negative error code if not. changed to: * Returns zero if volume is all right and a negative error code if not. Signed-off-by: Jiang Jian Signed-off-by: Richard Weinberger

ubi: block: Fix typos in comments

2022-09-21T09:32:27Z

Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall Signed-off-by: Richard Weinberger

ubi: fastmap: Fix typo in comments

2022-09-21T09:32:27Z

There are a typo(dont't) in comments. Fix it. Signed-off-by: Zhang Jiaming Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: Fix repeated words in comments

2022-09-21T09:32:27Z

Delete the redundant word 'a'. Delete the redundant word 'the'. Signed-off-by: Jilin Yuan Signed-off-by: Richard Weinberger

ubi: ubi-media.h: Fix comment typo

2022-09-21T09:12:18Z

The double `the' is duplicated in the comment, remove one. Signed-off-by: Jason Wang Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: block: Remove in vain semicolon

2022-09-21T09:11:10Z

Remove the repeated ';' from code, it is not needed. Signed-off-by: Li zeming Reviewed-by: Zhihao Cheng [rw: Massaged commit message a bit] Signed-off-by: Richard Weinberger