| Message ID | 20170903120757.14968-8-ard.biesheuvel@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, 3 Sep 2017, Ard Biesheuvel wrote: > To avoid absolute references that are subject to runtime relocation > when running a kernel built with CONFIG_RELOCATABLE=y, use relative > references in the smp.alt entries. > > Cc: Russell King <linux@armlinux.org.uk> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> > --- > arch/arm/include/asm/assembler.h | 4 ++-- > arch/arm/include/asm/processor.h | 2 +- > arch/arm/kernel/head.S | 10 +++++----- > 3 files changed, 8 insertions(+), 8 deletions(-) > > diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h > index 341e4ed1ef84..a0906c1fc65d 100644 > --- a/arch/arm/include/asm/assembler.h > +++ b/arch/arm/include/asm/assembler.h > @@ -260,7 +260,7 @@ > */ > #define ALT_UP(instr...) \ > .pushsection ".alt.smp.init", "a" ;\ > - .long 9998b ;\ > + .long 9998b - . ;\ > 9997: instr ;\ > .if . - 9997b == 2 ;\ > nop ;\ > @@ -272,7 +272,7 @@ > #define ALT_UP_B(label) \ > .equ up_b_offset, label - 9998b ;\ > .pushsection ".alt.smp.init", "a" ;\ > - .long 9998b ;\ > + .long 9998b - . ;\ > W(b) . + up_b_offset ;\ > .popsection > #else > diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h > index c3d5fc124a05..3667b395bb17 100644 > --- a/arch/arm/include/asm/processor.h > +++ b/arch/arm/include/asm/processor.h > @@ -92,7 +92,7 @@ unsigned long get_wchan(struct task_struct *p); > #define __ALT_SMP_ASM(smp, up) \ > "9998: " smp "\n" \ > " .pushsection \".alt.smp.init\", \"a\"\n" \ > - " .long 9998b\n" \ > + " .long 9998b - .\n" \ > " " up "\n" \ > " .popsection\n" > #else > diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S > index 6e9df3663a57..ec22f42fd8bb 100644 > --- a/arch/arm/kernel/head.S > +++ b/arch/arm/kernel/head.S > @@ -548,14 +548,15 @@ smp_on_up: > __do_fixup_smp_on_up: > cmp r4, r5 > reths lr > - ldmia r4!, {r0, r6} > - ARM( str r6, [r0, r3] ) > - THUMB( add r0, r0, r3 ) > + ldmia r4, {r0, r6} > + ARM( str r6, [r0, r4] ) > + THUMB( add r0, r0, r4 ) > + add r4, r4, #8 > #ifdef __ARMEB__ > THUMB( mov r6, r6, ror #16 ) @ Convert word order for big-endian. > #endif > THUMB( strh r6, [r0], #2 ) @ For Thumb-2, store as two halfwords > - THUMB( mov r6, r6, lsr #16 ) @ to be robust against misaligned r3. > + THUMB( mov r6, r6, lsr #16 ) @ to be robust against misaligned r0. > THUMB( strh r6, [r0] ) > b __do_fixup_smp_on_up > ENDPROC(__do_fixup_smp_on_up) > @@ -564,7 +565,6 @@ ENTRY(fixup_smp) > stmfd sp!, {r4 - r6, lr} > mov r4, r0 > add r5, r0, r1 > - mov r3, #0 > bl __do_fixup_smp_on_up > ldmfd sp!, {r4 - r6, pc} > ENDPROC(fixup_smp) > -- > 2.11.0 > >
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 341e4ed1ef84..a0906c1fc65d 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -260,7 +260,7 @@ */ #define ALT_UP(instr...) \ .pushsection ".alt.smp.init", "a" ;\ - .long 9998b ;\ + .long 9998b - . ;\ 9997: instr ;\ .if . - 9997b == 2 ;\ nop ;\ @@ -272,7 +272,7 @@ #define ALT_UP_B(label) \ .equ up_b_offset, label - 9998b ;\ .pushsection ".alt.smp.init", "a" ;\ - .long 9998b ;\ + .long 9998b - . ;\ W(b) . + up_b_offset ;\ .popsection #else diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h index c3d5fc124a05..3667b395bb17 100644 --- a/arch/arm/include/asm/processor.h +++ b/arch/arm/include/asm/processor.h @@ -92,7 +92,7 @@ unsigned long get_wchan(struct task_struct *p); #define __ALT_SMP_ASM(smp, up) \ "9998: " smp "\n" \ " .pushsection \".alt.smp.init\", \"a\"\n" \ - " .long 9998b\n" \ + " .long 9998b - .\n" \ " " up "\n" \ " .popsection\n" #else diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 6e9df3663a57..ec22f42fd8bb 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -548,14 +548,15 @@ smp_on_up: __do_fixup_smp_on_up: cmp r4, r5 reths lr - ldmia r4!, {r0, r6} - ARM( str r6, [r0, r3] ) - THUMB( add r0, r0, r3 ) + ldmia r4, {r0, r6} + ARM( str r6, [r0, r4] ) + THUMB( add r0, r0, r4 ) + add r4, r4, #8 #ifdef __ARMEB__ THUMB( mov r6, r6, ror #16 ) @ Convert word order for big-endian. #endif THUMB( strh r6, [r0], #2 ) @ For Thumb-2, store as two halfwords - THUMB( mov r6, r6, lsr #16 ) @ to be robust against misaligned r3. + THUMB( mov r6, r6, lsr #16 ) @ to be robust against misaligned r0. THUMB( strh r6, [r0] ) b __do_fixup_smp_on_up ENDPROC(__do_fixup_smp_on_up) @@ -564,7 +565,6 @@ ENTRY(fixup_smp) stmfd sp!, {r4 - r6, lr} mov r4, r0 add r5, r0, r1 - mov r3, #0 bl __do_fixup_smp_on_up ldmfd sp!, {r4 - r6, pc} ENDPROC(fixup_smp)
To avoid absolute references that are subject to runtime relocation when running a kernel built with CONFIG_RELOCATABLE=y, use relative references in the smp.alt entries. Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm/include/asm/assembler.h | 4 ++-- arch/arm/include/asm/processor.h | 2 +- arch/arm/kernel/head.S | 10 +++++----- 3 files changed, 8 insertions(+), 8 deletions(-)