The following commit has been merged into the locking/urgent branch of tip:
Commit-ID: 55d2eba8e7cd439c11cdb204898c2d384227629b Gitweb: https://git.kernel.org/tip/55d2eba8e7cd439c11cdb204898c2d384227629b Author: Peter Zijlstra <pet...@infradead.org> AuthorDate: Wed, 16 Dec 2020 12:21:36 +01:00 Committer: Peter Zijlstra <pet...@infradead.org> CommitterDate: Fri, 18 Dec 2020 16:53:12 +01:00 jump_label: Fix usage in module __init When the static_key is part of the module, and the module calls static_key_inc/enable() from it's __init section *AND* has a static_branch_*() user in that very same __init section, things go wobbly. If the static_key lives outside the module, jump_label_add_module() would append this module's sites to the key and jump_label_update() would take the static_key_linked() branch and all would be fine. If all the sites are outside of __init, then everything will be fine too. However, when all is aligned just as described above, jump_label_update() calls __jump_label_update(.init = false) and we'll not update sites in __init text. Fixes: 19483677684b ("jump_label: Annotate entries that operate on __init code earlier") Reported-by: Dexuan Cui <de...@microsoft.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Acked-by: Josh Poimboeuf <jpoim...@redhat.com> Tested-by: Jessica Yu <j...@kernel.org> Link: https://lkml.kernel.org/r/20201216135435.gv3...@hirez.programming.kicks-ass.net --- kernel/jump_label.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 015ef90..c6a39d6 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -793,6 +793,7 @@ int jump_label_text_reserved(void *start, void *end) static void jump_label_update(struct static_key *key) { struct jump_entry *stop = __stop___jump_table; + bool init = system_state < SYSTEM_RUNNING; struct jump_entry *entry; #ifdef CONFIG_MODULES struct module *mod; @@ -804,15 +805,16 @@ static void jump_label_update(struct static_key *key) preempt_disable(); mod = __module_address((unsigned long)key); - if (mod) + if (mod) { stop = mod->jump_entries + mod->num_jump_entries; + init = mod->state == MODULE_STATE_COMING; + } preempt_enable(); #endif entry = static_key_entries(key); /* if there are no users, entry can be NULL */ if (entry) - __jump_label_update(key, entry, stop, - system_state < SYSTEM_RUNNING); + __jump_label_update(key, entry, stop, init); } #ifdef CONFIG_STATIC_KEYS_SELFTEST
