From 1e5977b62f896e844b548c3007ace9e1dfa7f9ed Mon Sep 17 00:00:00 2001 From: Michael Biebl Date: Sat, 11 Apr 2020 21:28:04 +0200 Subject: New upstream version 1.23.90 --- shared/systemd/src/basic/macro.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'shared/systemd/src/basic/macro.h') diff --git a/shared/systemd/src/basic/macro.h b/shared/systemd/src/basic/macro.h index fc733366..6cd9c516 100644 --- a/shared/systemd/src/basic/macro.h +++ b/shared/systemd/src/basic/macro.h @@ -172,6 +172,11 @@ static inline size_t ALIGN_TO(size_t l, size_t ali) { /* align to next higher power-of-2 (except for: 0 => 0, overflow => 0) */ static inline unsigned long ALIGN_POWER2(unsigned long u) { + + /* Avoid subtraction overflow */ + if (u == 0) + return 0; + /* clz(0) is undefined */ if (u == 1) return 1; @@ -183,6 +188,29 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) { return 1UL << (sizeof(u) * 8 - __builtin_clzl(u - 1UL)); } +static inline size_t GREEDY_ALLOC_ROUND_UP(size_t l) { + size_t m; + + /* Round up allocation sizes a bit to some reasonable, likely larger value. This is supposed to be + * used for cases which are likely called in an allocation loop of some form, i.e. that repetitively + * grow stuff, for example strv_extend() and suchlike. + * + * Note the difference to GREEDY_REALLOC() here, as this helper operates on a single size value only, + * and rounds up to next multiple of 2, needing no further counter. + * + * Note the benefits of direct ALIGN_POWER2() usage: type-safety for size_t, sane handling for very + * small (i.e. <= 2) and safe handling for very large (i.e. > SSIZE_MAX) values. */ + + if (l <= 2) + return 2; /* Never allocate less than 2 of something. */ + + m = ALIGN_POWER2(l); + if (m == 0) /* overflow? */ + return l; + + return m; +} + #ifndef __COVERITY__ # define VOID_0 ((void)0) #else -- cgit 1.3.0-6-gf8a5