[PATCH 1/2] ARM: kvm: fix a bad BSYM() usage

Russell King - ARM Linux linux at arm.linux.org.uk
Sat May 9 13:10:57 PDT 2015


On Sat, May 09, 2015 at 10:07:17PM +0200, Christoffer Dall wrote:
> On Fri, May 08, 2015 at 05:08:42PM +0100, Russell King wrote:
> > BSYM() should only be used when refering to local symbols in the same
> > assembly file which are resolved by the assembler, and not for
> > linker-fixed up symbols.  The use of BSYM() with panic is incorrect as
> > the linker is involved in fixing up this relocation, and it knows
> > whether panic() is ARM or Thumb.
> > 
> > Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
> > ---
> >  arch/arm/kvm/interrupts.S | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
> > index 79caf79b304a..87847d2c5f99 100644
> > --- a/arch/arm/kvm/interrupts.S
> > +++ b/arch/arm/kvm/interrupts.S
> > @@ -309,7 +309,7 @@ ENTRY(kvm_call_hyp)
> >  THUMB(	orr	r2, r2, #PSR_T_BIT	)
> >  	msr	spsr_cxsf, r2
> >  	mrs	r1, ELR_hyp
> > -	ldr	r2, =BSYM(panic)
> > +	ldr	r2, =panic
> >  	msr	ELR_hyp, r2
> >  	ldr	r0, =\panic_str
> >  	clrex				@ Clear exclusive monitor
> > -- 
> > 1.8.3.1
> > 
> Indeed, the linker figures it out as it should.  It does seem like the
> right result is produced with the BSYM() macro as well so not sure what
> the harm is.
> 
> Anyway, I've queued this to merge via the KVM tree.

I already have it in my tree (and linux-next) as the second patch (which
removes the BSYM macro entirely) depends on this.

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