From a15b852c220e698161e55e3b85f3534d19424fdf Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 31 Mar 2021 02:02:12 +0000 Subject: [PATCH] static_call: Fix static_call_update() sanity check MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit stable inclusion from stable-5.10.26 commit e5154ea8e48fccde1b2fbd30a1616b002e47f3c6 bugzilla: 51363 -------------------------------- commit 38c93587375053c5b9ef093f4a5ea754538cba32 upstream. Sites that match init_section_contains() get marked as INIT. For built-in code init_sections contains both __init and __exit text. OTOH kernel_text_address() only explicitly includes __init text (and there are no __exit text markers). Match what jump_label already does and ignore the warning for INIT sites. Also see the excellent changelog for commit: 8f35eaa5f2de ("jump_label: Don't warn on __exit jump entries") Fixes: 9183c3f9ed710 ("static_call: Add inline static call infrastructure") Reported-by: Sumit Garg Signed-off-by: Peter Zijlstra (Intel) Acked-by: Jarkko Sakkinen Tested-by: Sumit Garg Link: https://lkml.kernel.org/r/20210318113610.739542434@infradead.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Chen Jun Acked-by:  Weilong Chen Signed-off-by: Zheng Zengkai --- kernel/jump_label.c | 8 ++++++++ kernel/static_call.c | 11 ++++++++++- 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 015ef903ce8c..a0c325664190 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -407,6 +407,14 @@ static bool jump_label_can_update(struct jump_entry *entry, bool init) return false; if (!kernel_text_address(jump_entry_code(entry))) { + /* + * This skips patching built-in __exit, which + * is part of init_section_contains() but is + * not part of kernel_text_address(). + * + * Skipping built-in __exit is fine since it + * will never be executed. + */ WARN_ONCE(!jump_entry_is_init(entry), "can't patch jump_label at %pS", (void *)jump_entry_code(entry)); diff --git a/kernel/static_call.c b/kernel/static_call.c index 84565c2a41b8..db914da6e785 100644 --- a/kernel/static_call.c +++ b/kernel/static_call.c @@ -182,7 +182,16 @@ void __static_call_update(struct static_call_key *key, void *tramp, void *func) } if (!kernel_text_address((unsigned long)site_addr)) { - WARN_ONCE(1, "can't patch static call site at %pS", + /* + * This skips patching built-in __exit, which + * is part of init_section_contains() but is + * not part of kernel_text_address(). + * + * Skipping built-in __exit is fine since it + * will never be executed. + */ + WARN_ONCE(!static_call_is_init(site), + "can't patch static call site at %pS", site_addr); continue; } -- GitLab