From aa7e564bf30e996aea3c47dd96ba6f85bdc804db Mon Sep 17 00:00:00 2001 From: asomers Date: Fri, 24 Jun 2016 21:44:46 +0000 Subject: [PATCH] Fix bitstring allocation on 32-bit platforms sys/sys/bitstring.h Fix a rounding calculation that could undersize a bitstring on 32-bit platforms. tests/sys/sys/bitstring_test.h Add a test for bitstr_size PR: 210260 Reported by: Mark Millard Reviewed by: gibbs Approved by: re (marius) Sponsored by: Spectra Logic Corp Differential Revision: https://reviews.freebsd.org/D6848 --- sys/sys/bitstring.h | 13 +++++++++---- tests/sys/sys/bitstring_test.c | 12 ++++++++++++ 2 files changed, 21 insertions(+), 4 deletions(-) diff --git a/sys/sys/bitstring.h b/sys/sys/bitstring.h index fa0ee19d859..32465d11ab2 100644 --- a/sys/sys/bitstring.h +++ b/sys/sys/bitstring.h @@ -75,6 +75,12 @@ typedef unsigned long bitstr_t; #define _BITSTR_MASK (~0UL) #define _BITSTR_BITS (sizeof(bitstr_t) * 8) +#ifdef roundup2 +#define _bit_roundup2 roundup2 +#else +#define _bit_roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */ +#endif + /* bitstr_t in bit string containing the bit. */ static inline int _bit_idx(int _bit) @@ -104,9 +110,8 @@ _bit_make_mask(int _start, int _stop) } /*----------------------------- Public Interface -----------------------------*/ -/* Number of bytes consumed by a bit string of nbits bits */ -#define bitstr_size(_nbits) \ - (((_nbits) + _BITSTR_BITS - 1) / 8) +/* Number of bytes allocated for a bit string of nbits bits */ +#define bitstr_size(_nbits) (_bit_roundup2(_nbits, _BITSTR_BITS) / 8) /* Allocate a bit string initialized with no bits set. */ #ifdef _KERNEL @@ -123,7 +128,7 @@ bit_alloc(int _nbits) } #endif -/* Allocate a bit string on the stack with no bits set. */ +/* Allocate a bit string on the stack */ #define bit_decl(name, nbits) \ ((name)[bitstr_size(nbits) / sizeof(bitstr_t)]) diff --git a/tests/sys/sys/bitstring_test.c b/tests/sys/sys/bitstring_test.c index f80115ae287..fbfe78275b2 100644 --- a/tests/sys/sys/bitstring_test.c +++ b/tests/sys/sys/bitstring_test.c @@ -102,6 +102,17 @@ ATF_TC_BODY(bitstr_in_struct, tc) bit_nclear(test_struct.bitstr, 0, 8); } +ATF_TC_WITHOUT_HEAD(bitstr_size); +ATF_TC_BODY(bitstr_size, tc) +{ + size_t sob = sizeof(bitstr_t); + + ATF_CHECK_EQ(0, bitstr_size(0)); + ATF_CHECK_EQ(sob, bitstr_size(1)); + ATF_CHECK_EQ(sob, bitstr_size(sob * 8)); + ATF_CHECK_EQ(2 * sob, bitstr_size(sob * 8 + 1)); +} + BITSTRING_TC_DEFINE(bit_set) /* bitstr_t *bitstr, int nbits, const char *memloc */ { @@ -407,6 +418,7 @@ ATF_TP_ADD_TCS(tp) { ATF_TP_ADD_TC(tp, bitstr_in_struct); + ATF_TP_ADD_TC(tp, bitstr_size); BITSTRING_TC_ADD(tp, bit_set); BITSTRING_TC_ADD(tp, bit_clear); BITSTRING_TC_ADD(tp, bit_ffs); -- 2.45.0