On Saturday 26 December 2015 19:06:40 Yury Norov wrote: > All new 32-bit architectures should have 64-bit off_t type, but existing > architectures has 32-bit ones. It's worth mentioning here that ever the architectures that only have 64-bit off_t in the kernel ( arc, c6x, h8300, hexagon, metag, nios2, opernrisc, tile32 and unicore32) may use a libc with 32-bit off_t in their libc, and therefore want to limit the file size to 4GB unless specified differently in the open flags. > To handle it, new config option is added to arch/Kconfig that defaults > ARCH_32BIT_OFF_T to be disabled by default. All existing 32-bit architectures > enable it explicitly here. > > New option affects force_o_largefile() behaviour. Namely, if off_t is > 64-bits long, we have no reason to reject user to open big files. > > Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx> The patch looks mostly right, just a few stylistic comments: > diff --git a/arch/Kconfig b/arch/Kconfig > index 4e949e5..1e5e6c8 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -233,6 +233,10 @@ config ARCH_THREAD_INFO_ALLOCATOR > config ARCH_WANTS_DYNAMIC_TASK_STRUCT > bool > > +config ARCH_32BIT_OFF_T > + def_bool n > + depends on !64BIT 'bool' is the same as 'def_bool n', and the former is more common, so please use that. > --- a/arch/ia64/Kconfig > +++ b/arch/ia64/Kconfig > @@ -11,6 +11,7 @@ menu "Processor type and features" > > config IA64 > bool > + select ARCH_32BIT_OFF_T if !64BIT > select ARCH_MIGHT_HAVE_PC_PARPORT > select ARCH_MIGHT_HAVE_PC_SERIO > select PCI if (!IA64_HP_SIM) No need to patch IA64, we don't support 32-bit kernels on that architecture > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index db49e0d..2026a9e 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -7,6 +7,7 @@ config PPC32 > config 32BIT > bool > default y if PPC32 > + select ARCH_32BIT_OFF_T > > config 64BIT > bool It seems the preferred way of writing this in powerpc is to put select ARCH_32BIT_OFF_T if PPC32 under config PPC > diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig > index 3a55f49..d05a143 100644 > --- a/arch/s390/Kconfig > +++ b/arch/s390/Kconfig > @@ -64,6 +64,7 @@ config ARCH_SUPPORTS_UPROBES > > config S390 > def_bool y > + select ARCH_32BIT_OFF_T if !64BIT > select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE > select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS > select ARCH_HAS_ELF_RANDOMIZE 32-bit s390 support was removed some time ago, so this is no longer needed. > diff --git a/include/linux/fcntl.h b/include/linux/fcntl.h > index 76ce329..2e27443 100644 > --- a/include/linux/fcntl.h > +++ b/include/linux/fcntl.h > @@ -5,7 +5,8 @@ > > > #ifndef force_o_largefile > -#define force_o_largefile() (BITS_PER_LONG != 32) > +#define force_o_largefile() ((BITS_PER_LONG != 32) \ > + || !IS_ENABLED(CONFIG_ARCH_32BIT_OFF_T)) > #endif > > #if BITS_PER_LONG == 32 I just realized that while I suggested the expression you wrote here, the BITS_PER_LONG check isn't actually needed, we can just make it #define force_o_largefile() (!IS_ENABLED(CONFIG_ARCH_32BIT_OFF_T)) Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
