[PATCH v2 0/2] ABI: handle 32-bit off_t for 32-bit and compat ABIs

[PATCH v2 0/2] ABI: handle 32-bit off_t for 32-bit and compat ABIs

[Yury Norov]

32-bit off_t is supported only for old 32-bit and compat ABIs. New ABIs
are 64-bit length only. This patchset makes 64-bit length the default
for off_t, and reverts it for old architectures where needed. It does not
change the behaviour of existing code.

First patch makes all compat users of generic unistd.h to use non-compat
versions of openat and open_by_handle_at. Tile that requires old behaviour
is turned around.

Second patch introduces ARCH_32BIT_OFF_T config option, disabled by default,
but enables it explicitly for existing 32-bit architectures.

v2:
 - removed ARCH_32BIT_OFF_T for IA64, s390, as 32-bit kernels are not supported there.
 - patch 2: added Arnd's note,
 - patch 2: stylistic changes.

Yury Norov (2):
  ABI: compat: use non-compat openat and open_by_handle_at variants
  32-bit ABI: introduce ARCH_32BIT_OFF_T config option

 arch/Kconfig                      | 4 ++++
 arch/arc/Kconfig                  | 1 +
 arch/arm/Kconfig                  | 1 +
 arch/blackfin/Kconfig             | 1 +
 arch/cris/Kconfig                 | 1 +
 arch/frv/Kconfig                  | 1 +
 arch/h8300/Kconfig                | 1 +
 arch/hexagon/Kconfig              | 1 +
 arch/ia64/Kconfig                 | 1 +
 arch/m32r/Kconfig                 | 1 +
 arch/m68k/Kconfig                 | 1 +
 arch/metag/Kconfig                | 1 +
 arch/microblaze/Kconfig           | 1 +
 arch/mips/Kconfig                 | 1 +
 arch/mn10300/Kconfig              | 1 +
 arch/nios2/Kconfig                | 1 +
 arch/openrisc/Kconfig             | 1 +
 arch/parisc/Kconfig               | 1 +
 arch/powerpc/Kconfig              | 1 +
 arch/s390/Kconfig                 | 1 +
 arch/score/Kconfig                | 1 +
 arch/sh/Kconfig                   | 1 +
 arch/sparc/Kconfig                | 1 +
 arch/tile/Kconfig                 | 1 +
 arch/tile/kernel/compat.c         | 3 +++
 arch/unicore32/Kconfig            | 1 +
 arch/x86/Kconfig                  | 1 +
 arch/x86/um/Kconfig               | 1 +
 arch/xtensa/Kconfig               | 1 +
 include/linux/fcntl.h             | 3 ++-
 include/uapi/asm-generic/unistd.h | 5 ++---
 31 files changed, 38 insertions(+), 4 deletions(-)

-- 
2.5.0

[PATCH 1/2] compat ABI: use non-compat openat and open_by_handle_at variants

[Yury Norov]

The only difference is that non-compat version forces O_LARGEFILE,
and it should be the default behaviour for all architectures, as
we don't support 32-bit off_t. The only exception is tile32, that
continues with compat version of syscalls.

Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Chris Metcalf <cmetcalf@ezchip.com> [for tile]
---
 arch/tile/kernel/compat.c         | 3 +++
 include/uapi/asm-generic/unistd.h | 5 ++---
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/tile/kernel/compat.c b/arch/tile/kernel/compat.c
index 4912084..489ae19 100644
--- a/arch/tile/kernel/compat.c
+++ b/arch/tile/kernel/compat.c
@@ -94,6 +94,9 @@ COMPAT_SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned int, offset_high,
 #define compat_sys_readahead sys32_readahead
 #define sys_llseek compat_sys_llseek
 
+#define sys_openat		compat_sys_openat
+#define sys_open_by_handle_at	compat_sys_open_by_handle_at
+
 /* Call the assembly trampolines where necessary. */
 #define compat_sys_rt_sigreturn _compat_sys_rt_sigreturn
 #define sys_clone _sys_clone
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 1324b02..07761e5 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -175,7 +175,7 @@ __SYSCALL(__NR_fchownat, sys_fchownat)
 #define __NR_fchown 55
 __SYSCALL(__NR_fchown, sys_fchown)
 #define __NR_openat 56
-__SC_COMP(__NR_openat, sys_openat, compat_sys_openat)
+__SYSCALL(__NR_openat, sys_openat)
 #define __NR_close 57
 __SYSCALL(__NR_close, sys_close)
 #define __NR_vhangup 58
@@ -673,8 +673,7 @@ __SYSCALL(__NR_fanotify_mark, sys_fanotify_mark)
 #define __NR_name_to_handle_at         264
 __SYSCALL(__NR_name_to_handle_at, sys_name_to_handle_at)
 #define __NR_open_by_handle_at         265
-__SC_COMP(__NR_open_by_handle_at, sys_open_by_handle_at, \
-	  compat_sys_open_by_handle_at)
+__SYSCALL(__NR_open_by_handle_at, sys_open_by_handle_at)
 #define __NR_clock_adjtime 266
 __SC_COMP(__NR_clock_adjtime, sys_clock_adjtime, compat_sys_clock_adjtime)
 #define __NR_syncfs 267
-- 
2.5.0

[PATCH 2/2] 32-bit ABI: introduce ARCH_32BIT_OFF_T config option

[Yury Norov]

All new 32-bit architectures should have 64-bit off_t type, but existing
architectures has 32-bit ones.

To handle it, new config option is added to arch/Kconfig that defaults
ARCH_32BIT_OFF_T to be disabled for non-64 bit architectures. 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.

Note that even if architectures has only 64-bit off_t in the kernel
(arc, c6x, h8300, hexagon, metag, nios2, openrisc, tile32 and unicore32),
a libc may use 32-bit off_t, and therefore want to limit the file size
to 4GB unless specified differently in the open flags.

Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
---
 arch/Kconfig            | 4 ++++
 arch/arc/Kconfig        | 1 +
 arch/arm/Kconfig        | 1 +
 arch/blackfin/Kconfig   | 1 +
 arch/cris/Kconfig       | 1 +
 arch/frv/Kconfig        | 1 +
 arch/h8300/Kconfig      | 1 +
 arch/hexagon/Kconfig    | 1 +
 arch/m32r/Kconfig       | 1 +
 arch/m68k/Kconfig       | 1 +
 arch/metag/Kconfig      | 1 +
 arch/microblaze/Kconfig | 1 +
 arch/mips/Kconfig       | 1 +
 arch/mn10300/Kconfig    | 1 +
 arch/nios2/Kconfig      | 1 +
 arch/openrisc/Kconfig   | 1 +
 arch/parisc/Kconfig     | 1 +
 arch/powerpc/Kconfig    | 1 +
 arch/score/Kconfig      | 1 +
 arch/sh/Kconfig         | 1 +
 arch/sparc/Kconfig      | 1 +
 arch/tile/Kconfig       | 1 +
 arch/unicore32/Kconfig  | 1 +
 arch/x86/Kconfig        | 1 +
 arch/x86/um/Kconfig     | 1 +
 arch/xtensa/Kconfig     | 1 +
 include/linux/fcntl.h   | 2 +-
 27 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index 4e949e5..b356bb6 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
+	bool
+	depends on !64BIT
+
 config HAVE_REGS_AND_STACK_ACCESS_API
 	bool
 	help
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 6312f60..570dc39 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -9,6 +9,7 @@
 config ARC
 	def_bool y
 	select ARCH_SUPPORTS_ATOMIC_RMW if ARC_HAS_LLSC
+	select ARCH_32BIT_OFF_T
 	select BUILDTIME_EXTABLE_SORT
 	select COMMON_CLK
 	select CLONE_BACKWARDS
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 34e1569..dafdebe 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1,6 +1,7 @@
 config ARM
 	bool
 	default y
+	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index af76634..9b5fc06 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -12,6 +12,7 @@ config RWSEM_XCHGADD_ALGORITHM
 
 config BLACKFIN
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_DYNAMIC_FTRACE
diff --git a/arch/cris/Kconfig b/arch/cris/Kconfig
index e086f9e..5bc9203 100644
--- a/arch/cris/Kconfig
+++ b/arch/cris/Kconfig
@@ -50,6 +50,7 @@ config LOCKDEP_SUPPORT
 config CRIS
 	bool
 	default y
+	select ARCH_32BIT_OFF_T
 	select HAVE_IDE
 	select GENERIC_ATOMIC64
 	select HAVE_UID16
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index 34aa193..09b82fc 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -1,6 +1,7 @@
 config FRV
 	bool
 	default y
+	select ARCH_32BIT_OFF_T
 	select HAVE_IDE
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_PERF_EVENTS
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index dd3ac75..7761f4a 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -1,5 +1,6 @@
 config H8300
         def_bool y
+	select ARCH_32BIT_OFF_T
 	select GENERIC_ATOMIC64
 	select HAVE_UID16
 	select VIRT_TO_BUS
diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index 4dc89d1..29836fc 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -3,6 +3,7 @@ comment "Linux Kernel Configuration for Hexagon"
 
 config HEXAGON
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select HAVE_OPROFILE
 	# Other pending projects/to-do items.
 	# select HAVE_REGS_AND_STACK_ACCESS_API
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index 9e44bbd..c6865a9 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -1,6 +1,7 @@
 config M32R
 	bool
 	default y
+	select ARCH_32BIT_OFF_T
 	select HAVE_IDE
 	select HAVE_OPROFILE
 	select INIT_ALL_POSSIBLE
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 498b567..e9897e4 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -1,6 +1,7 @@
 config M68K
 	bool
 	default y
+	select ARCH_32BIT_OFF_T
 	select ARCH_MIGHT_HAVE_PC_PARPORT if ISA
 	select HAVE_IDE
 	select HAVE_AOUT if MMU
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index 0b389a8..6b44d37 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -1,5 +1,6 @@
 config METAG
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select EMBEDDED
 	select GENERIC_ATOMIC64
 	select GENERIC_CLOCKEVENTS
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 0bce820..4b293e5 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -1,5 +1,6 @@
 config MICROBLAZE
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_WANT_IPC_PARSE_VERSION
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 71683a8..2e42c26 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1,6 +1,7 @@
 config MIPS
 	bool
 	default y
+	select ARCH_32BIT_OFF_T if !64BIT
 	select ARCH_SUPPORTS_UPROBES
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig
index 78ae555..edf7372 100644
--- a/arch/mn10300/Kconfig
+++ b/arch/mn10300/Kconfig
@@ -1,5 +1,6 @@
 config MN10300
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select HAVE_OPROFILE
 	select HAVE_UID16
 	select GENERIC_IRQ_SHOW
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index 4375554..a38fc38 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -1,5 +1,6 @@
 config NIOS2
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select CLKSRC_OF
 	select GENERIC_ATOMIC64
diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 443f44d..7bef847 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -5,6 +5,7 @@
 
 config OPENRISC
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select OF
 	select OF_EARLY_FLATTREE
 	select IRQ_DOMAIN
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 729f891..8bf0fe2 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -1,5 +1,6 @@
 config PARISC
 	def_bool y
+	select ARCH_32BIT_OFF_T if !64BIT
 	select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select HAVE_IDE
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index db49e0d..113d893 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -88,6 +88,7 @@ config ARCH_HAS_DMA_SET_COHERENT_MASK
 config PPC
 	bool
 	default y
+	select ARCH_32BIT_OFF_T if PPC32
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
 	select BINFMT_ELF
diff --git a/arch/score/Kconfig b/arch/score/Kconfig
index 366e1b5..bc7bc7a 100644
--- a/arch/score/Kconfig
+++ b/arch/score/Kconfig
@@ -2,6 +2,7 @@ menu "Machine selection"
 
 config SCORE
        def_bool y
+       select ARCH_32BIT_OFF_T
        select GENERIC_IRQ_SHOW
        select GENERIC_IOMAP
        select GENERIC_ATOMIC64
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index d514df7e..1e9d63a 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -52,6 +52,7 @@ config SUPERH
 
 config SUPERH32
 	def_bool ARCH = "sh"
+	select ARCH_32BIT_OFF_T
 	select HAVE_KPROBES
 	select HAVE_KRETPROBES
 	select HAVE_IOREMAP_PROT if MMU && !X2TLB
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 56442d2..1268a2a 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -46,6 +46,7 @@ config SPARC
 
 config SPARC32
 	def_bool !64BIT
+	select ARCH_32BIT_OFF_T
 	select GENERIC_ATOMIC64
 	select CLZ_TAB
 	select HAVE_UID16
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 106c21b..ef2e7ec 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -3,6 +3,7 @@
 
 config TILE
 	def_bool y
+	select ARCH_32BIT_OFF_T if !64BIT
 	select HAVE_PERF_EVENTS
 	select USE_PMC if PERF_EVENTS
 	select HAVE_DMA_ATTRS
diff --git a/arch/unicore32/Kconfig b/arch/unicore32/Kconfig
index c9faddc..1a8c3c0 100644
--- a/arch/unicore32/Kconfig
+++ b/arch/unicore32/Kconfig
@@ -1,5 +1,6 @@
 config UNICORE32
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
 	select HAVE_MEMBLOCK
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index db3622f..cc16336 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -20,6 +20,7 @@ config X86
 	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
 	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
 	select ANON_INODES
+	select ARCH_32BIT_OFF_T			if X86_32
 	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_DISCARD_MEMBLOCK
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig
index ed56a1c..8436bcd 100644
--- a/arch/x86/um/Kconfig
+++ b/arch/x86/um/Kconfig
@@ -21,6 +21,7 @@ config 64BIT
 config X86_32
 	def_bool !64BIT
 	select HAVE_AOUT
+	select ARCH_32BIT_OFF_T
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select MODULES_USE_ELF_REL
 	select CLONE_BACKWARDS
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 82044f7..7ff155a 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -3,6 +3,7 @@ config ZONE_DMA
 
 config XTENSA
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_WANT_FRAME_POINTERS
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select ARCH_WANT_OPTIONAL_GPIOLIB
diff --git a/include/linux/fcntl.h b/include/linux/fcntl.h
index 76ce329..46960a1 100644
--- a/include/linux/fcntl.h
+++ b/include/linux/fcntl.h
@@ -5,7 +5,7 @@
 
 
 #ifndef force_o_largefile
-#define force_o_largefile() (BITS_PER_LONG != 32)
+#define force_o_largefile() (!IS_ENABLED(CONFIG_ARCH_32BIT_OFF_T))
 #endif
 
 #if BITS_PER_LONG == 32
-- 
2.5.0

Re: [PATCH 2/2] 32-bit ABI: introduce ARCH_32BIT_OFF_T config option

[Arnd Bergmann]

On Tuesday 29 December 2015 12:26:35 Yury Norov wrote:
> All new 32-bit architectures should have 64-bit off_t type, but existing
> architectures has 32-bit ones.
> 
> To handle it, new config option is added to arch/Kconfig that defaults
> ARCH_32BIT_OFF_T to be disabled for non-64 bit architectures. 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.
> 
> Note that even if architectures has only 64-bit off_t in the kernel
> (arc, c6x, h8300, hexagon, metag, nios2, openrisc, tile32 and unicore32),
> a libc may use 32-bit off_t, and therefore want to limit the file size
> to 4GB unless specified differently in the open flags.
> 
> Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
> 

Acked-by: Arnd Bergmann <arnd@arndb.de>

Should we merge the two patches through my asm-generic tree now, or should
we keep them in the ilp32 series, any preferences?

I think either way works.

	Arnd

Re: [PATCH 2/2] 32-bit ABI: introduce ARCH_32BIT_OFF_T config option

[Yury Norov]

On Tue, Dec 29, 2015 at 12:02:33PM +0100, Arnd Bergmann wrote:
> On Tuesday 29 December 2015 12:26:35 Yury Norov wrote:
> > All new 32-bit architectures should have 64-bit off_t type, but existing
> > architectures has 32-bit ones.
> > 
> > To handle it, new config option is added to arch/Kconfig that defaults
> > ARCH_32BIT_OFF_T to be disabled for non-64 bit architectures. 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.
> > 
> > Note that even if architectures has only 64-bit off_t in the kernel
> > (arc, c6x, h8300, hexagon, metag, nios2, openrisc, tile32 and unicore32),
> > a libc may use 32-bit off_t, and therefore want to limit the file size
> > to 4GB unless specified differently in the open flags.
> > 
> > Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
> > 
> 
> Acked-by: Arnd Bergmann <arnd@arndb.de>
> 
> Should we merge the two patches through my asm-generic tree now, or should
> we keep them in the ilp32 series, any preferences?
> 
> I think either way works.
> 
> 	Arnd

I'd prefer asm-generic tree because they are not related to ILP32 only.

Yury.

Re: [PATCH 2/2] 32-bit ABI: introduce ARCH_32BIT_OFF_T config option

[Thomas Gleixner]

On Tue, 29 Dec 2015, Yury Norov wrote:

> All new 32-bit architectures should have 64-bit off_t type, but existing
> architectures has 32-bit ones.
> 
> To handle it, new config option is added to arch/Kconfig that defaults
> ARCH_32BIT_OFF_T to be disabled for non-64 bit architectures. 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.
> 
> Note that even if architectures has only 64-bit off_t in the kernel
> (arc, c6x, h8300, hexagon, metag, nios2, openrisc, tile32 and unicore32),
> a libc may use 32-bit off_t, and therefore want to limit the file size
> to 4GB unless specified differently in the open flags.

For the x86 part: Acked-by: Thomas Gleixner <tglx@linutronix.de>

Re: [PATCH 2/2] 32-bit ABI: introduce ARCH_32BIT_OFF_T config option

[Arnd Bergmann]

On Tuesday 29 December 2015 14:43:41 Yury Norov wrote:
> On Tue, Dec 29, 2015 at 12:02:33PM +0100, Arnd Bergmann wrote:
> > On Tuesday 29 December 2015 12:26:35 Yury Norov wrote:
> > 
> > Acked-by: Arnd Bergmann <arnd@arndb.de>
> > 
> > Should we merge the two patches through my asm-generic tree now, or should
> > we keep them in the ilp32 series, any preferences?
> > 
> > I think either way works.
> > 
> >       Arnd
> 
> I'd prefer asm-generic tree because they are not related to ILP32 only.
> 

Ok, I'll add it there after collecting a few more Acks. Generally speaking I
prefer to keep asm-generic patches in whatever series depends on them, as
there are normally very few changes, but it makes sense to merge this one
regardless just to make sure no other dependencies get added in case someone
submits a new architecture port at the same time.

	Arnd