Date: Sat, 23 May 2020 19:52:20 +0000 (UTC) From: Emmanuel Vadot <manu@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r361422 - head/sys/netinet/tcp_stacks Message-ID: <202005231952.04NJqKHa022015@repo.freebsd.org>
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Author: manu Date: Sat May 23 19:52:20 2020 New Revision: 361422 URL: https://svnweb.freebsd.org/changeset/base/361422 Log: bbr: Use arc4random_uniform from libkern. This unbreak LINT build Reported by: jenkins, melifaro Modified: head/sys/netinet/tcp_stacks/bbr.c Modified: head/sys/netinet/tcp_stacks/bbr.c ============================================================================== --- head/sys/netinet/tcp_stacks/bbr.c Sat May 23 19:06:57 2020 (r361421) +++ head/sys/netinet/tcp_stacks/bbr.c Sat May 23 19:52:20 2020 (r361422) @@ -43,6 +43,7 @@ __FBSDID("$FreeBSD$"); #include <sys/arb.h> #include <sys/module.h> #include <sys/kernel.h> +#include <sys/libkern.h> #ifdef TCP_HHOOK #include <sys/hhook.h> #endif @@ -3095,43 +3096,6 @@ bbr_lt_bw_samp_done(struct tcp_bbr *bbr, uint64_t bw, bbr->r_ctl.rc_lt_bw = bw; bbr_reset_lt_bw_interval(bbr, cts); bbr_log_type_ltbw(bbr, cts, 5, 0, (uint32_t)bw, 0, timin); -} - -/* - * RRS: Copied from user space! - * Calculate a uniformly distributed random number less than upper_bound - * avoiding "modulo bias". - * - * Uniformity is achieved by generating new random numbers until the one - * returned is outside the range [0, 2**32 % upper_bound). This - * guarantees the selected random number will be inside - * [2**32 % upper_bound, 2**32) which maps back to [0, upper_bound) - * after reduction modulo upper_bound. - */ -static uint32_t -arc4random_uniform(uint32_t upper_bound) -{ - uint32_t r, min; - - if (upper_bound < 2) - return 0; - - /* 2**32 % x == (2**32 - x) % x */ - min = -upper_bound % upper_bound; - - /* - * This could theoretically loop forever but each retry has - * p > 0.5 (worst case, usually far better) of selecting a - * number inside the range we need, so it should rarely need - * to re-roll. - */ - for (;;) { - r = arc4random(); - if (r >= min) - break; - } - - return r % upper_bound; } static void
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