The following commit has been merged into the locking/urgent branch of tip:
Commit-ID: 38c93587375053c5b9ef093f4a5ea754538cba32 Gitweb: https://git.kernel.org/tip/38c93587375053c5b9ef093f4a5ea754538cba32 Author: Peter Zijlstra <pet...@infradead.org> AuthorDate: Thu, 18 Mar 2021 11:31:51 +01:00 Committer: Peter Zijlstra <pet...@infradead.org> CommitterDate: Fri, 19 Mar 2021 13:16:44 +01:00 static_call: Fix static_call_update() sanity check 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 <sumit.g...@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Acked-by: Jarkko Sakkinen <jar...@kernel.org> Tested-by: Sumit Garg <sumit.g...@linaro.org> Link: https://lkml.kernel.org/r/20210318113610.739542...@infradead.org --- 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 c6a39d6..ba39fbb 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 fc22590..2c5950b 100644 --- a/kernel/static_call.c +++ b/kernel/static_call.c @@ -181,7 +181,16 @@ void __static_call_update(struct static_call_key *key, void *tramp, void *func) continue; 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; }
