Date: Thu, 25 Jun 2026 03:08:56 +0000 From: Kyle Evans <kevans@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 4ffa7e126ed0 - main - kern: osd: trash a slot's methods upon deregistration Message-ID: <6a3c9bc8.1c118.366e5286@gitrepo.freebsd.org>
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The branch main has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=4ffa7e126ed0081b804bda6fb71a60acf49dabda commit 4ffa7e126ed0081b804bda6fb71a60acf49dabda Author: Kyle Evans <kevans@FreeBSD.org> AuthorDate: 2026-06-25 03:08:05 +0000 Commit: Kyle Evans <kevans@FreeBSD.org> CommitDate: 2026-06-25 03:08:24 +0000 kern: osd: trash a slot's methods upon deregistration This both lets us quickly identify a slot that's been deallocated while debugging, and forces us to take a fault if something tries to call one of the methods anyways somehow with osd_destructors[slot - 1] == NULL. Reviewed by: imp, jamie Differential Revision: https://reviews.freebsd.org/D48075 --- sys/kern/kern_osd.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/sys/kern/kern_osd.c b/sys/kern/kern_osd.c index b64735e7f93a..94377b39dbc1 100644 --- a/sys/kern/kern_osd.c +++ b/sys/kern/kern_osd.c @@ -180,6 +180,18 @@ osd_deregister(u_int type, u_int slot) osdm[type].osd_destructors[slot - 1] = NULL; OSD_DEBUG("Slot deregistration (type=%u, slot=%u).", type, slot); +#ifdef INVARIANTS + /* + * We trash the slot's osd_methods upon deregistration so that we take + * a fault if something calls them, rather than potentially + * inadvertently executing some arbitrary function if another module's + * been mapped over the one that deregistered. + */ + for (u_int method = 0; method < osdm[type].osd_nmethods; method++) { + OSD_METHOD(osdm[type], slot, method) = (void *)0xdeadc0de; + } +#endif + rm_wunlock(&osdm[type].osd_object_lock); sx_xunlock(&osdm[type].osd_module_lock); }home | help
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