Messages in this thread Patch in this message | | | Date | Tue, 01 Sep 2020 11:48:07 -0000 | From | "tip-bot2 for Peter Zijlstra" <> | Subject | [tip: core/static_call] jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved() |
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The following commit has been merged into the core/static_call branch of tip:
Commit-ID: 0db6e3734b130207026df1e78455fa98ca1d6f50 Gitweb: https://git.kernel.org/tip/0db6e3734b130207026df1e78455fa98ca1d6f50 Author: Peter Zijlstra <peterz@infradead.org> AuthorDate: Tue, 18 Aug 2020 15:57:39 +02:00 Committer: Ingo Molnar <mingo@kernel.org> CommitterDate: Tue, 01 Sep 2020 09:58:04 +02:00
jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved()
Nothing ensures the module exists while we're iterating mod->jump_entries in __jump_label_mod_text_reserved(), take a module reference to ensure the module sticks around.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20200818135804.504501338@infradead.org --- kernel/jump_label.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/kernel/jump_label.c b/kernel/jump_label.c index cdb3ffa..e661c61 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -539,19 +539,25 @@ static void static_key_set_mod(struct static_key *key, static int __jump_label_mod_text_reserved(void *start, void *end) { struct module *mod; + int ret; preempt_disable(); mod = __module_text_address((unsigned long)start); WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod); + if (!try_module_get(mod)) + mod = NULL; preempt_enable(); if (!mod) return 0; - - return __jump_label_text_reserved(mod->jump_entries, + ret = __jump_label_text_reserved(mod->jump_entries, mod->jump_entries + mod->num_jump_entries, start, end); + + module_put(mod); + + return ret; } static void __jump_label_mod_update(struct static_key *key)
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