Messages in this thread Patch in this message | | | Date | Sun, 19 Aug 2012 04:07:10 +0200 | From | Andi Kleen <> | Subject | Re: [PATCH 01/31] Disable const sections for PA-RISC |
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> > +config BROKEN_RODATA > > + bool > > + default y > > Could you please change this so we have a commonly defined HAVE_BROKEN_RODATA > symbol. Then arch's that have broken RO data can select this symbol. > If we experience tomorrow that sparc have the same issue then with > this patch sparc has to create a local definition of this symbol.
Here's an updated patch with the config placed in init/Kconfig. I'm not going to repost the whole series.
-Andi
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Disable const sections for PA-RISC v2
The PA-RISC tool chain seems to have some problem with correct read/write attributes on sections. This causes problems when the const sections are fixed up for other architecture to only contain truly read-only data.
Disable const sections for PA-RISC
This can cause a bit of noise with modpost.
v2: Move config to init/Kconfig Cc: James.Bottomley@HansenPartnership.com Signed-off-by: Andi Kleen <ak@linux.intel.com> --- arch/parisc/Kconfig | 1 + include/linux/init.h | 27 +++++++++++++++++++-------- init/Kconfig | 6 ++++++ 3 files changed, 26 insertions(+), 8 deletions(-)
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index 3ff21b5..77f9c81 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -19,6 +19,7 @@ config PARISC select ARCH_HAVE_NMI_SAFE_CMPXCHG select GENERIC_SMP_IDLE_THREAD select GENERIC_STRNCPY_FROM_USER + select BROKEN_RODATA help The PA-RISC microprocessor is designed by Hewlett-Packard and used diff --git a/include/linux/init.h b/include/linux/init.h index 5e664f6..c2f06b3 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -43,10 +43,21 @@ discard it in modules) */ #define __init __section(.init.text) __cold notrace #define __initdata __section(.init.data) -#define __initconst __section(.init.rodata) +#define __initconst __constsection(.init.rodata) #define __exitdata __section(.exit.data) #define __exit_call __used __section(.exitcall.exit) +/* + * Some architecture have tool chains which do not handle rodata attributes + * correctly. For those disable special sections for const, so that other + * architectures can annotate correctly. + */ +#ifdef CONFIG_BROKEN_RODATA +#define __constsection(x) +#else +#define __constsection(x) __section(x) +#endif + /* * modpost check for section mismatches during the kernel build. * A section mismatch happens when there are references from a @@ -66,7 +77,7 @@ */ #define __ref __section(.ref.text) noinline #define __refdata __section(.ref.data) -#define __refconst __section(.ref.rodata) +#define __refconst __constsection(.ref.rodata) /* compatibility defines */ #define __init_refok __ref @@ -85,26 +96,26 @@ /* Used for HOTPLUG */ #define __devinit __section(.devinit.text) __cold notrace #define __devinitdata __section(.devinit.data) -#define __devinitconst __section(.devinit.rodata) +#define __devinitconst __constsection(.devinit.rodata) #define __devexit __section(.devexit.text) __exitused __cold notrace #define __devexitdata __section(.devexit.data) -#define __devexitconst __section(.devexit.rodata) +#define __devexitconst __constsection(.devexit.rodata) /* Used for HOTPLUG_CPU */ #define __cpuinit __section(.cpuinit.text) __cold notrace #define __cpuinitdata __section(.cpuinit.data) -#define __cpuinitconst __section(.cpuinit.rodata) +#define __cpuinitconst __constsection(.cpuinit.rodata) #define __cpuexit __section(.cpuexit.text) __exitused __cold notrace #define __cpuexitdata __section(.cpuexit.data) -#define __cpuexitconst __section(.cpuexit.rodata) +#define __cpuexitconst __constsection(.cpuexit.rodata) /* Used for MEMORY_HOTPLUG */ #define __meminit __section(.meminit.text) __cold notrace #define __meminitdata __section(.meminit.data) -#define __meminitconst __section(.meminit.rodata) +#define __meminitconst __constsection(.meminit.rodata) #define __memexit __section(.memexit.text) __exitused __cold notrace #define __memexitdata __section(.memexit.data) -#define __memexitconst __section(.memexit.rodata) +#define __memexitconst __constsection(.memexit.rodata) /* For assembly routines */ #define __HEAD .section ".head.text","ax" diff --git a/init/Kconfig b/init/Kconfig index af6c7f8..a8785db 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1612,4 +1612,10 @@ config PADATA depends on SMP bool +# Can be selected by architectures with broken toolchains +# that get confused by correct const<->read_only section +# mappings +config BROKEN_RODATA + bool + source "kernel/Kconfig.locks" -- 1.7.10.4
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