From: Andrew Murray andrew.murray@arm.com
[ Upstream commit 8f35eaa5f2de020073a48ad51112237c5932cfcc ]
On architectures that discard .exit.* sections at runtime, a warning is printed for each jump label that is used within an in-kernel __exit annotated function:
can't patch jump_label at ehci_hcd_cleanup+0x8/0x3c WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:410 __jump_label_update+0x12c/0x138
As these functions will never get executed (they are free'd along with the rest of initmem) - we do not need to patch them and should not display any warnings.
The warning is displayed because the test required to satisfy jump_entry_is_init is based on init_section_contains (__init_begin to __init_end) whereas the test in __jump_label_update is based on init_kernel_text (_sinittext to _einittext) via kernel_text_address).
Fixes: 19483677684b ("jump_label: Annotate entries that operate on __init code earlier") Signed-off-by: Andrew Murray andrew.murray@arm.com Acked-by: Peter Zijlstra (Intel) peterz@infradead.org Acked-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/jump_label.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/jump_label.c b/kernel/jump_label.c index df3008419a1d0..cdb3ffab128b6 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -407,7 +407,9 @@ static bool jump_label_can_update(struct jump_entry *entry, bool init) return false;
if (!kernel_text_address(jump_entry_code(entry))) { - WARN_ONCE(1, "can't patch jump_label at %pS", (void *)jump_entry_code(entry)); + WARN_ONCE(!jump_entry_is_init(entry), + "can't patch jump_label at %pS", + (void *)jump_entry_code(entry)); return false; }