On Fri, 11 Aug 2017, Ard Biesheuvel wrote:
> On 11 August 2017 at 16:13, Tony Lindgren <tony@xxxxxxxxxxx> wrote:
> > * Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> [170805 13:54]:
> >> Replace the open coded PC relative offset calculations with a pair
> >> of adr_l invocations.
> >>
> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> >> ---
> >> arch/arm/kernel/head.S | 12 ++----------
> >> 1 file changed, 2 insertions(+), 10 deletions(-)
> >>
> >> diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
> >> index 6e9df3663a57..aed341e0f530 100644
> >> --- a/arch/arm/kernel/head.S
> >> +++ b/arch/arm/kernel/head.S
> >> @@ -523,19 +523,11 @@ ARM_BE8(rev r0, r0) @ byteswap if big endian
> >> retne lr
> >>
> >> __fixup_smp_on_up:
> >> - adr r0, 1f
> >> - ldmia r0, {r3 - r5}
> >> - sub r3, r0, r3
> >> - add r4, r4, r3
> >> - add r5, r5, r3
> >> + adr_l r4, __smpalt_begin
> >> + adr_l r5, __smpalt_end
> >> b __do_fixup_smp_on_up
> >> ENDPROC(__fixup_smp)
> >>
> >> - .align
> >> -1: .word .
> >> - .word __smpalt_begin
> >> - .word __smpalt_end
> >> -
> >> .pushsection .data
> >> .globl smp_on_up
> >> smp_on_up:
> >
> > Ard, it's this one that cause boot to fail on omap3.
> > The rest of your set works for me with just this one
> > left out.
> >
>
> I'm completely puzzled.
Found it.
You replaced:
- adr r0, 1f
- ldmia r0, {r3 - r5}
- sub r3, r0, r3
- add r4, r4, r3
- add r5, r5, r3
+ adr_l r4, __smpalt_begin
+ adr_l r5, __smpalt_end
b __do_fixup_smp_on_up
Notice that r3 is now uninitialized.
Now have a look at the code for __do_fixup_smp_on_up.
Nicolas
