| Message ID | 20170903120757.14968-9-ard.biesheuvel@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, 3 Sep 2017, Ard Biesheuvel wrote: > Replace the open coded PC relative offset calculations with a pair > of adr_l invocations. This ensures these quantities are invariant > under runtime relocation. You probably should add that this patch must be applied on top of "ARM: kernel: use relative references for UP/SMP alternatives" because of the expected r3 value prior to that patch. Acked-by: Nicolas Pitre <nico@linaro.org> > Cc: Russell King <linux@armlinux.org.uk> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > 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 ec22f42fd8bb..db6b823f20a4 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: > -- > 2.11.0 > >
On 4 September 2017 at 17:19, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: > On Sun, 3 Sep 2017, Ard Biesheuvel wrote: > >> Replace the open coded PC relative offset calculations with a pair >> of adr_l invocations. This ensures these quantities are invariant >> under runtime relocation. > > You probably should add that this patch must be applied on top of "ARM: > kernel: use relative references for UP/SMP alternatives" because of the > expected r3 value prior to that patch. > > Acked-by: Nicolas Pitre <nico@linaro.org> > Yes, that is why I needed to reorder them. I will add a mention to the commit log. Thanks,
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index ec22f42fd8bb..db6b823f20a4 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:
Replace the open coded PC relative offset calculations with a pair of adr_l invocations. This ensures these quantities are invariant under runtime relocation. Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm/kernel/head.S | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-)