Messages in this thread | | | Date | Thu, 22 Aug 2019 15:16:20 -0500 | From | Josh Poimboeuf <> | Subject | Re: [RFC v4 13/18] arm64: sleep: Prevent stack frame warnings from objtool |
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On Fri, Aug 16, 2019 at 01:23:58PM +0100, Raphael Gault wrote: > This code doesn't respect the Arm PCS but it is intended this > way. Adapting it to respect the PCS would result in altering the > behaviour. > > In order to suppress objtool's warnings, we setup a stack frame > for __cpu_suspend_enter and annotate cpu_resume and _cpu_resume > as having non-standard stack frames. > > Signed-off-by: Raphael Gault <raphael.gault@arm.com> > --- > arch/arm64/kernel/sleep.S | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S > index f5b04dd8a710..55c7c099d32c 100644 > --- a/arch/arm64/kernel/sleep.S > +++ b/arch/arm64/kernel/sleep.S > @@ -1,5 +1,6 @@ > /* SPDX-License-Identifier: GPL-2.0 */ > #include <linux/errno.h> > +#include <linux/frame.h> > #include <linux/linkage.h> > #include <asm/asm-offsets.h> > #include <asm/assembler.h> > @@ -90,6 +91,7 @@ ENTRY(__cpu_suspend_enter) > str x0, [x1] > add x0, x0, #SLEEP_STACK_DATA_SYSTEM_REGS > stp x29, lr, [sp, #-16]! > + mov x29, sp > bl cpu_do_suspend > ldp x29, lr, [sp], #16 > mov x0, #1 > @@ -146,3 +148,6 @@ ENTRY(_cpu_resume) > mov x0, #0 > ret > ENDPROC(_cpu_resume) > + > + asm_stack_frame_non_standard cpu_resume > + asm_stack_frame_non_standard _cpu_resume
We usually put these annotations immediately after the functions they're annotating. And they should resemble the C macros like
STACK_FRAME_NON_STANDARD(cpu_resume)
-- Josh
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