Date: Fri, 26 Oct 2018 21:03:57 +0000 (UTC) From: Conrad Meyer <cem@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r339790 - head/sys/dev/random Message-ID: <201810262103.w9QL3vJe091349@repo.freebsd.org>
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Author: cem Date: Fri Oct 26 21:03:57 2018 New Revision: 339790 URL: https://svnweb.freebsd.org/changeset/base/339790 Log: Fortuna: Add failpoints to simulate initial seeding conditions Set debug.fail_point.random_fortuna_pre_read=return(1) and debug.fail_point.random_fortuna_seeded=return(1) to return to unseeded status (sort of). See the Differential URL for more detail. The goal is to reproduce e.g. Lev's recent CURRENT report[1] about failing newfs arc4random(3) usage (fixed in r338542). No functional change when failpoints are not set. [1]: https://lists.freebsd.org/pipermail/freebsd-current/2018-September/071067.html Reported by: lev Reviewed by: delphij, markm Approved by: secteam (delphij) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D17047 Modified: head/sys/dev/random/fortuna.c Modified: head/sys/dev/random/fortuna.c ============================================================================== --- head/sys/dev/random/fortuna.c Fri Oct 26 21:00:26 2018 (r339789) +++ head/sys/dev/random/fortuna.c Fri Oct 26 21:03:57 2018 (r339790) @@ -39,6 +39,7 @@ __FBSDID("$FreeBSD$"); #ifdef _KERNEL #include <sys/param.h> +#include <sys/fail.h> #include <sys/kernel.h> #include <sys/lock.h> #include <sys/malloc.h> @@ -385,6 +386,18 @@ random_fortuna_pre_read(void) } #ifdef _KERNEL + /* + * When set, pretend we do not have enough entropy to reseed yet. + */ + KFAIL_POINT_CODE(DEBUG_FP, random_fortuna_pre_read, { + if (RETURN_VALUE != 0) { + RANDOM_RESEED_UNLOCK(); + return; + } + }); +#endif + +#ifdef _KERNEL fortuna_state.fs_lasttime = now; #endif @@ -441,6 +454,14 @@ random_fortuna_read(uint8_t *buf, u_int bytecount) bool random_fortuna_seeded(void) { + +#ifdef _KERNEL + /* When set, act as if we are not seeded. */ + KFAIL_POINT_CODE(DEBUG_FP, random_fortuna_seeded, { + if (RETURN_VALUE != 0) + fortuna_state.fs_counter = UINT128_ZERO; + }); +#endif return (!uint128_is_zero(fortuna_state.fs_counter)); }
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