From e8ec04938c446e5f4dc53e0147f0f679995012ee Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Wed, 10 Jun 2020 18:41:32 -0700 Subject: lib/lz4/lz4_decompress.c: document deliberate use of `&' This operation was intentional, but tools such as smatch will warn that it might not have been. Signed-off-by: Andrew Morton Cc: Yann Collet Cc: Vasily Averin Cc: Gao Xiang Link: http://lkml.kernel.org/r/3bf931c6ea0cae3e23f3485801986859851b4f04.camel@perches.com Signed-off-by: Linus Torvalds --- lib/lz4/lz4_decompress.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'lib') diff --git a/lib/lz4/lz4_decompress.c b/lib/lz4/lz4_decompress.c index 0c9d3ad17e0f..5371dab6b481 100644 --- a/lib/lz4/lz4_decompress.c +++ b/lib/lz4/lz4_decompress.c @@ -141,6 +141,9 @@ static FORCE_INLINE int LZ4_decompress_generic( * space in the output for those 18 bytes earlier, upon * entering the shortcut (in other words, there is a * combined check for both stages). + * + * The & in the likely() below is intentionally not && so that + * some compilers can produce better parallelized runtime code */ if ((endOnInput ? length != RUN_MASK : length <= 8) /* -- cgit From 81c4f4d924d5d009b5ed785a3e22b18d0f7b831f Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Wed, 10 Jun 2020 18:41:41 -0700 Subject: lib: fix bitmap_parse() on 64-bit big endian archs Commit 2d6261583be0 ("lib: rework bitmap_parse()") does not take into account order of halfwords on 64-bit big endian architectures. As result (at least) Receive Packet Steering, IRQ affinity masks and runtime kernel test "test_bitmap" get broken on s390. [andriy.shevchenko@linux.intel.com: convert infinite while loop to a for loop] Link: http://lkml.kernel.org/r/20200609140535.87160-1-andriy.shevchenko@linux.intel.com Fixes: 2d6261583be0 ("lib: rework bitmap_parse()") Signed-off-by: Alexander Gordeev Signed-off-by: Andy Shevchenko Signed-off-by: Andrew Morton Reviewed-by: Andy Shevchenko Cc: Yury Norov Cc: Amritha Nambiar Cc: Arnaldo Carvalho de Melo Cc: Chris Wilson Cc: Kees Cook Cc: Matthew Wilcox Cc: Miklos Szeredi Cc: Rasmus Villemoes Cc: Steffen Klassert Cc: "Tobin C . Harding" Cc: Vineet Gupta Cc: Will Deacon Cc: Willem de Bruijn Cc: Link: http://lkml.kernel.org/r/1591634471-17647-1-git-send-email-agordeev@linux.ibm.com Signed-off-by: Linus Torvalds --- lib/bitmap.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/bitmap.c b/lib/bitmap.c index 21a7640c5eed..0364452b1617 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -741,8 +741,9 @@ int bitmap_parse(const char *start, unsigned int buflen, int chunks = BITS_TO_U32(nmaskbits); u32 *bitmap = (u32 *)maskp; int unset_bit; + int chunk; - while (1) { + for (chunk = 0; ; chunk++) { end = bitmap_find_region_reverse(start, end); if (start > end) break; @@ -750,7 +751,11 @@ int bitmap_parse(const char *start, unsigned int buflen, if (!chunks--) return -EOVERFLOW; - end = bitmap_get_x32_reverse(start, end, bitmap++); +#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN) + end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]); +#else + end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]); +#endif if (IS_ERR(end)) return PTR_ERR(end); } -- cgit From 6af132f3a11e6d2d9032ce51c882aa5933543255 Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Wed, 10 Jun 2020 18:41:53 -0700 Subject: lib: test get_count_order/long in test_bitops.c Add some tests for get_count_order/long in test_bitops.c. [akpm@linux-foundation.org: define local `i'] [akpm@linux-foundation.org: enhancement, warning fix, cleanup per Geert] [akpm@linux-foundation.org: fix loop bound, per Wei Yang] Signed-off-by: Wei Yang Signed-off-by: Andrew Morton Reviewed-by: Andy Shevchenko Cc: Christian Brauner Cc: Geert Uytterhoeven Link: http://lkml.kernel.org/r/20200602223728.32722-1-richard.weiyang@gmail.com Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 10 +++++----- lib/test_bitops.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 56 insertions(+), 7 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index cb98741601bd..5beec9c833ce 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2052,15 +2052,15 @@ config TEST_LKM If unsure, say N. config TEST_BITOPS - tristate "Test module for compilation of clear_bit/set_bit operations" + tristate "Test module for compilation of bitops operations" depends on m help This builds the "test_bitops" module that is much like the TEST_LKM module except that it does a basic exercise of the - clear_bit and set_bit macros to make sure there are no compiler - warnings from C=1 sparse checker or -Wextra compilations. It has - no dependencies and doesn't run or load unless explicitly requested - by name. for example: modprobe test_bitops. + set/clear_bit macros and get_count_order/long to make sure there are + no compiler warnings from C=1 sparse checker or -Wextra + compilations. It has no dependencies and doesn't run or load unless + explicitly requested by name. for example: modprobe test_bitops. If unsure, say N. diff --git a/lib/test_bitops.c b/lib/test_bitops.c index fd50b3ae4a14..ced25e3a779b 100644 --- a/lib/test_bitops.c +++ b/lib/test_bitops.c @@ -9,7 +9,11 @@ #include #include -/* a tiny module only meant to test set/clear_bit */ +/* a tiny module only meant to test + * + * set/clear_bit + * get_count_order/long + */ /* use an enum because thats the most common BITMAP usage */ enum bitops_fun { @@ -24,14 +28,59 @@ enum bitops_fun { static DECLARE_BITMAP(g_bitmap, BITOPS_LENGTH); +static unsigned int order_comb[][2] = { + {0x00000003, 2}, + {0x00000004, 2}, + {0x00001fff, 13}, + {0x00002000, 13}, + {0x50000000, 31}, + {0x80000000, 31}, + {0x80003000, 32}, +}; + +#ifdef CONFIG_64BIT +static unsigned long order_comb_long[][2] = { + {0x0000000300000000, 34}, + {0x0000000400000000, 34}, + {0x00001fff00000000, 45}, + {0x0000200000000000, 45}, + {0x5000000000000000, 63}, + {0x8000000000000000, 63}, + {0x8000300000000000, 64}, +}; +#endif + static int __init test_bitops_startup(void) { + int i; + pr_warn("Loaded test module\n"); set_bit(BITOPS_4, g_bitmap); set_bit(BITOPS_7, g_bitmap); set_bit(BITOPS_11, g_bitmap); set_bit(BITOPS_31, g_bitmap); set_bit(BITOPS_88, g_bitmap); + + for (i = 0; i < ARRAY_SIZE(order_comb); i++) { + if (order_comb[i][1] != get_count_order(order_comb[i][0])) + pr_warn("get_count_order wrong for %x\n", + order_comb[i][0]); + } + + for (i = 0; i < ARRAY_SIZE(order_comb); i++) { + if (order_comb[i][1] != get_count_order_long(order_comb[i][0])) + pr_warn("get_count_order_long wrong for %x\n", + order_comb[i][0]); + } + +#ifdef CONFIG_64BIT + for (i = 0; i < ARRAY_SIZE(order_comb_long); i++) { + if (order_comb_long[i][1] != + get_count_order_long(order_comb_long[i][0])) + pr_warn("get_count_order_long wrong for %lx\n", + order_comb_long[i][0]); + } +#endif return 0; } @@ -55,6 +104,6 @@ static void __exit test_bitops_unstartup(void) module_init(test_bitops_startup); module_exit(test_bitops_unstartup); -MODULE_AUTHOR("Jesse Brandeburg "); +MODULE_AUTHOR("Jesse Brandeburg , Wei Yang "); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Bit testing module"); -- cgit