Reviewers: carrot, xur, Message: Hi Rong and Carrot, could you take a look at this patch, thanks!
The modification is in upstream (with a minor modification). Background - There is the need to agree on the runtime linker path for the various ARM hard-float ports that distros are working on right now. Without doing this, we'll break binary compatibility between the distros. The conclusion was made. And here is the detailed information - https://wiki.linaro.org/OfficeofCTO/HardFloat/LinkerPathCallApr2012 ===== Patch starts diff --git a/gcc/config/arm/linux-eabi.h b/gcc/config/arm/linux-eabi.h index 3a32188..58d06c2 100644 --- a/gcc/config/arm/linux-eabi.h +++ b/gcc/config/arm/linux-eabi.h @@ -32,7 +32,8 @@ while (false) /* We default to a soft-float ABI so that binaries can run on all - target hardware. */ + target hardware. If you override this to use the hard-float ABI then + change the setting of GLIBC_DYNAMIC_LINKER_DEFAULT as well. */ #undef TARGET_DEFAULT_FLOAT_ABI #define TARGET_DEFAULT_FLOAT_ABI ARM_FLOAT_ABI_SOFT @@ -59,10 +60,26 @@ #undef SUBTARGET_EXTRA_LINK_SPEC #define SUBTARGET_EXTRA_LINK_SPEC " -m " TARGET_LINKER_EMULATION -/* Use ld-linux.so.3 so that it will be possible to run "classic" - GNU/Linux binaries on an EABI system. */ +/* GNU/Linux on ARM currently supports three dynamic linkers: + - ld-linux.so.2 - for the legacy ABI + - ld-linux.so.3 - for the EABI-derived soft-float ABI + - ld-linux-armhf.so.3 - for the EABI-derived hard-float ABI. + All the dynamic linkers live in /lib. + We default to soft-float, but this can be overridden by changing both + GLIBC_DYNAMIC_LINKER_DEFAULT and TARGET_DEFAULT_FLOAT_ABI. */ + #undef GLIBC_DYNAMIC_LINKER -#define GLIBC_DYNAMIC_LINKER RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3" +#define GLIBC_DYNAMIC_LINKER_SOFT_FLOAT \ + RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3" +#define GLIBC_DYNAMIC_LINKER_HARD_FLOAT \ + RUNTIME_ROOT_PREFIX "/lib/ld-linux-armhf.so.3" +#define GLIBC_DYNAMIC_LINKER_DEFAULT \ + RUNTIME_ROOT_PREFIX GLIBC_DYNAMIC_LINKER_SOFT_FLOAT + +#define GLIBC_DYNAMIC_LINKER \ + "%{mfloat-abi=hard:" GLIBC_DYNAMIC_LINKER_HARD_FLOAT "} \ + %{mfloat-abi=soft*:" GLIBC_DYNAMIC_LINKER_SOFT_FLOAT "} \ + %{!mfloat-abi=*:" GLIBC_DYNAMIC_LINKER_DEFAULT "}" /* At this point, bpabi.h will have clobbered LINK_SPEC. We want to use the GNU/Linux version, not the generic BPABI version. */ Description: Hi Rong and Carrot, could you take a look at this patch, thanks! The modification is in upstream (with a minor modification). Background - There is the need to agree on the runtime linker path for the various ARM hard-float ports that distros are working on right now. Without doing this, we'll break binary compatibility between the distros. The conclusion was made. And here is the detailed information - https://wiki.linaro.org/OfficeofCTO/HardFloat/LinkerPathCallApr2012 ===== Patch starts diff --git a/gcc/config/arm/linux-eabi.h b/gcc/config/arm/linux-eabi.h index 3a32188..58d06c2 100644 --- a/gcc/config/arm/linux-eabi.h +++ b/gcc/config/arm/linux-eabi.h @@ -32,7 +32,8 @@ while (false) /* We default to a soft-float ABI so that binaries can run on all - target hardware. */ + target hardware. If you override this to use the hard-float ABI then + change the setting of GLIBC_DYNAMIC_LINKER_DEFAULT as well. */ #undef TARGET_DEFAULT_FLOAT_ABI #define TARGET_DEFAULT_FLOAT_ABI ARM_FLOAT_ABI_SOFT @@ -59,10 +60,26 @@ #undef SUBTARGET_EXTRA_LINK_SPEC #define SUBTARGET_EXTRA_LINK_SPEC " -m " TARGET_LINKER_EMULATION -/* Use ld-linux.so.3 so that it will be possible to run "classic" - GNU/Linux binaries on an EABI system. */ +/* GNU/Linux on ARM currently supports three dynamic linkers: + - ld-linux.so.2 - for the legacy ABI + - ld-linux.so.3 - for the EABI-derived soft-float ABI + - ld-linux-armhf.so.3 - for the EABI-derived hard-float ABI. + All the dynamic linkers live in /lib. + We default to soft-float, but this can be overridden by changing both + GLIBC_DYNAMIC_LINKER_DEFAULT and TARGET_DEFAULT_FLOAT_ABI. */ + #undef GLIBC_DYNAMIC_LINKER -#define GLIBC_DYNAMIC_LINKER RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3" +#define GLIBC_DYNAMIC_LINKER_SOFT_FLOAT \ + RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3" +#define GLIBC_DYNAMIC_LINKER_HARD_FLOAT \ + RUNTIME_ROOT_PREFIX "/lib/ld-linux-armhf.so.3" +#define GLIBC_DYNAMIC_LINKER_DEFAULT \ + RUNTIME_ROOT_PREFIX GLIBC_DYNAMIC_LINKER_SOFT_FLOAT + +#define GLIBC_DYNAMIC_LINKER \ + "%{mfloat-abi=hard:" GLIBC_DYNAMIC_LINKER_HARD_FLOAT "} \ + %{mfloat-abi=soft*:" GLIBC_DYNAMIC_LINKER_SOFT_FLOAT "} \ + %{!mfloat-abi=*:" GLIBC_DYNAMIC_LINKER_DEFAULT "}" /* At this point, bpabi.h will have clobbered LINK_SPEC. We want to use the GNU/Linux version, not the generic BPABI version. */ Please review this at http://codereview.appspot.com/6206055/ Affected files: M gcc/config/arm/linux-eabi.h Index: gcc/config/arm/linux-eabi.h diff --git a/gcc/config/arm/linux-eabi.h b/gcc/config/arm/linux-eabi.h index 3a32188..58d06c2 100644 --- a/gcc/config/arm/linux-eabi.h +++ b/gcc/config/arm/linux-eabi.h @@ -32,7 +32,8 @@ while (false) /* We default to a soft-float ABI so that binaries can run on all - target hardware. */ + target hardware. If you override this to use the hard-float ABI then + change the setting of GLIBC_DYNAMIC_LINKER_DEFAULT as well. */ #undef TARGET_DEFAULT_FLOAT_ABI #define TARGET_DEFAULT_FLOAT_ABI ARM_FLOAT_ABI_SOFT @@ -59,10 +60,26 @@ #undef SUBTARGET_EXTRA_LINK_SPEC #define SUBTARGET_EXTRA_LINK_SPEC " -m " TARGET_LINKER_EMULATION -/* Use ld-linux.so.3 so that it will be possible to run "classic" - GNU/Linux binaries on an EABI system. */ +/* GNU/Linux on ARM currently supports three dynamic linkers: + - ld-linux.so.2 - for the legacy ABI + - ld-linux.so.3 - for the EABI-derived soft-float ABI + - ld-linux-armhf.so.3 - for the EABI-derived hard-float ABI. + All the dynamic linkers live in /lib. + We default to soft-float, but this can be overridden by changing both + GLIBC_DYNAMIC_LINKER_DEFAULT and TARGET_DEFAULT_FLOAT_ABI. */ + #undef GLIBC_DYNAMIC_LINKER -#define GLIBC_DYNAMIC_LINKER RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3" +#define GLIBC_DYNAMIC_LINKER_SOFT_FLOAT \ + RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3" +#define GLIBC_DYNAMIC_LINKER_HARD_FLOAT \ + RUNTIME_ROOT_PREFIX "/lib/ld-linux-armhf.so.3" +#define GLIBC_DYNAMIC_LINKER_DEFAULT \ + RUNTIME_ROOT_PREFIX GLIBC_DYNAMIC_LINKER_SOFT_FLOAT + +#define GLIBC_DYNAMIC_LINKER \ + "%{mfloat-abi=hard:" GLIBC_DYNAMIC_LINKER_HARD_FLOAT "} \ + %{mfloat-abi=soft*:" GLIBC_DYNAMIC_LINKER_SOFT_FLOAT "} \ + %{!mfloat-abi=*:" GLIBC_DYNAMIC_LINKER_DEFAULT "}" /* At this point, bpabi.h will have clobbered LINK_SPEC. We want to use the GNU/Linux version, not the generic BPABI version. */
