Date: Fri, 6 Aug 2021 05:13:35 GMT From: "David E. O'Brien" <obrien@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 17dc7d3add57 - stable/12 - Fortuna: Add failpoints to simulate initial seeding conditions Message-ID: <202108060513.1765DZgo000952@gitrepo.freebsd.org>
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The branch stable/12 has been updated by obrien: URL: https://cgit.FreeBSD.org/src/commit/?id=17dc7d3add57f8aa3bf5091644fb23d06a5b9c9f commit 17dc7d3add57f8aa3bf5091644fb23d06a5b9c9f Author: Conrad Meyer <cem@FreeBSD.org> AuthorDate: 2018-10-26 21:03:57 +0000 Commit: David E. O'Brien <obrien@FreeBSD.org> CommitDate: 2021-08-06 05:12:16 +0000 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 (cherry picked from commit 9b8d0fe462b2f3f689cb87fe34bd42c388e23d49) --- sys/dev/random/fortuna.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/sys/dev/random/fortuna.c b/sys/dev/random/fortuna.c index 866899846212..3a46d527fa9a 100644 --- a/sys/dev/random/fortuna.c +++ b/sys/dev/random/fortuna.c @@ -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> @@ -384,6 +385,18 @@ random_fortuna_pre_read(void) return; } +#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 @@ -442,5 +455,13 @@ 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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