| Message ID | 20190731161256.22210-2-andrew.murray@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: avoid out-of-line ll/sc atomics | expand |
On Wed, Jul 31, 2019 at 05:12:52PM +0100, Andrew Murray wrote: > 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). > > In addition to fixing this, we also remove an out-of-date comment > and use a WARN instead of a WARN_ONCE. > > Fixes: 19483677684b ("jump_label: Annotate entries that operate on __init code earlier") > Signed-off-by: Andrew Murray <andrew.murray@arm.com> > --- > 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 df3008419a1d..c984078a5c28 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)); > + if (!jump_entry_is_init(entry)) > + WARN_ONCE(1, "can't patch jump_label at %pS", > + (void *)jump_entry_code(entry)); It seems to me we can writes that as: WARN_ONCE(!jump_entry_is_init(entry), "can't patch jump_label at %pS", (void *)jump_entry_code(entry)); > return false; > } Other than that, Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
On Wed, Jul 31, 2019 at 06:41:56PM +0200, Peter Zijlstra wrote: > On Wed, Jul 31, 2019 at 05:12:52PM +0100, Andrew Murray wrote: > > 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). > > > > In addition to fixing this, we also remove an out-of-date comment > > and use a WARN instead of a WARN_ONCE. > > > > Fixes: 19483677684b ("jump_label: Annotate entries that operate on __init code earlier") > > Signed-off-by: Andrew Murray <andrew.murray@arm.com> > > --- > > 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 df3008419a1d..c984078a5c28 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)); > > + if (!jump_entry_is_init(entry)) > > + WARN_ONCE(1, "can't patch jump_label at %pS", > > + (void *)jump_entry_code(entry)); > > It seems to me we can writes that as: > > WARN_ONCE(!jump_entry_is_init(entry), > "can't patch jump_label at %pS", > (void *)jump_entry_code(entry)); > > > return false; > > } > > Other than that, > > Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Ah of course! I'll make this change on my respin and add your ack. Thanks. Thanks, Andrew Murray
diff --git a/kernel/jump_label.c b/kernel/jump_label.c index df3008419a1d..c984078a5c28 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)); + if (!jump_entry_is_init(entry)) + WARN_ONCE(1, "can't patch jump_label at %pS", + (void *)jump_entry_code(entry)); return false; }
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). In addition to fixing this, we also remove an out-of-date comment and use a WARN instead of a WARN_ONCE. Fixes: 19483677684b ("jump_label: Annotate entries that operate on __init code earlier") Signed-off-by: Andrew Murray <andrew.murray@arm.com> --- kernel/jump_label.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)