[PATCH 04/24] 32-bit userspace ABI: introduce ARCH_32BIT_OFF_T config option

From: Yury Norov <hidden>
Date: 2018-05-16 08:20:31
Also in: linux-arch, linux-arm-kernel, linux-doc, lkml
Subsystem: arm port, file locking (flock() and fcntl()/lockf()), linux for powerpc (32-bit and 64-bit), m68k architecture, microblaze architecture, mips, nios2 architecture, openrisc architecture, parisc architecture, qualcomm hexagon architecture, sparc + ultrasparc (sparc/sparc64), superh, synopsys arc architecture, tensilica xtensa port (xtensa), the rest, user-mode linux (uml), x86 architecture (32-bit and 64-bit) · Maintainers: Russell King, Jeff Layton, Chuck Lever, Madhavan Srinivasan, Michael Ellerman, Geert Uytterhoeven, Michal Simek, Thomas Bogendoerfer, Dinh Nguyen, Simon Schuster, Jonas Bonn, Stefan Kristiansson, Stafford Horne, "James E.J. Bottomley", Helge Deller, Brian Cain, "David S. Miller", Andreas Larsson, Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Vineet Gupta, Chris Zankel, Max Filippov, Linus Torvalds, Richard Weinberger, Anton Ivanov, Johannes Berg, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen

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

To enforce the rule, new config option is added to arch/Kconfig that defaults
ARCH_32BIT_OFF_T to be disabled for new 32-bit architectures. All existing
32-bit architectures enable it explicitly.

New option affects force_o_largefile() behaviour. Namely, if userspace
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 <redacted>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/Kconfig            | 15 +++++++++++++++
 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, 41 insertions(+), 1 deletion(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index 76c0b54443b1..ee079244dc3c 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig

@@ -264,6 +264,21 @@ config ARCH_THREAD_STACK_ALLOCATOR
 config ARCH_WANTS_DYNAMIC_TASK_STRUCT
 	bool
 
+config ARCH_32BIT_OFF_T
+	bool
+	depends on !64BIT
+	help
+	  All new 32-bit architectures should have 64-bit off_t type on
+	  userspace side which corresponds to the loff_t kernel type. This
+	  is the requirement for modern ABIs. Some existing architectures
+	  already have 32-bit off_t. This option is enabled for all such
+	  architectures explicitly. Namely: arc, arm, blackfin, cris, frv,
+	  h8300, hexagon, m32r, m68k, metag, microblaze, mips32, mn10300,
+	  nios2, openrisc, parisc32, powerpc32, score, sh, sparc, tile32,
+	  unicore32, x86_32 and xtensa. This is the complete list. Any
+	  new 32-bit architecture should declare 64-bit off_t type on user
+	  side and so should not enable this option.
+
 config HAVE_REGS_AND_STACK_ACCESS_API
 	bool
 	help

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index d76bf4a83740..9b48c82a12f6 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig

@@ -11,6 +11,7 @@ config ARC
 	select ARC_TIMERS
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_SUPPORTS_ATOMIC_RMW if ARC_HAS_LLSC
+	select ARCH_32BIT_OFF_T
 	select BUILDTIME_EXTABLE_SORT
 	select CLONE_BACKWARDS
 	select COMMON_CLK

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 7e3d53575486..825a611a9d86 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig

@@ -2,6 +2,7 @@
 config ARM
 	bool
 	default y
+	select ARCH_32BIT_OFF_T
 	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_DISCARD_MEMBLOCK if !HAVE_ARCH_PFN_VALID && !KEXEC
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU

diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index d9c2866ba618..5a99c1ccad67 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig

@@ -13,6 +13,7 @@ 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 cd5a0865c97f..db7ea0a9e805 100644
--- a/arch/cris/Kconfig
+++ b/arch/cris/Kconfig

@@ -54,6 +54,7 @@ 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 af369b05fed5..9dc671f8f4a6 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig

@@ -2,6 +2,7 @@
 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 091d6d04b5e5..6fc8a034ddb6 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 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 76d2f20d525e..f6e748178292 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig

@@ -4,6 +4,7 @@ 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 dd84ee194579..8d9c2244b144 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig

@@ -2,6 +2,7 @@
 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 785612b576f7..8aafd39b5142 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig

@@ -2,6 +2,7 @@
 config M68K
 	bool
 	default y
+	select ARCH_32BIT_OFF_T
 	select ARCH_MIGHT_HAVE_PC_PARPORT if ISA
 	select ARCH_NO_COHERENT_DMA_MMAP if !MMU
 	select HAVE_IDE

diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index c7b62a339539..8bc07fa5982d 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 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 3817a3e2146c..48270951c3aa 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_NO_COHERENT_DMA_MMAP if !MMU

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 8128c3b68d6b..3eb048042004 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig

@@ -2,6 +2,7 @@
 config MIPS
 	bool
 	default y
+	select ARCH_32BIT_OFF_T if !64BIT
 	select ARCH_BINFMT_ELF_STATE
 	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_DISCARD_MEMBLOCK

diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig
index e9d8d60bd28b..7840859b3f9f 100644
--- a/arch/mn10300/Kconfig
+++ b/arch/mn10300/Kconfig

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 config MN10300
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select HAVE_EXIT_THREAD
 	select HAVE_OPROFILE
 	select HAVE_UID16

diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index 3d4ec88f1db1..9b4a9cf4af3b 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 config NIOS2
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select TIMER_OF
 	select GENERIC_ATOMIC64
 	select GENERIC_CLOCKEVENTS

diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 339df7324e9c..24c7c25064e5 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig

@@ -6,6 +6,7 @@
 
 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 9792d8cf4f56..93f8cecbb741 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 config PARISC
 	def_bool y
+	select ARCH_32BIT_OFF_T if !64BIT
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select HAVE_IDE
 	select HAVE_OPROFILE

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 73ce5dd07642..4f38ce304b78 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig

@@ -134,6 +134,7 @@ config PPC
 	#
 	# Please keep this list sorted alphabetically.
 	#
+	select ARCH_32BIT_OFF_T if PPC32
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_SET_COHERENT_MASK
 	select ARCH_HAS_ELF_RANDOMIZE

diff --git a/arch/score/Kconfig b/arch/score/Kconfig
index d881f99c9ddd..7371e5fb18b9 100644
--- a/arch/score/Kconfig
+++ b/arch/score/Kconfig

@@ -3,6 +3,7 @@ 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 97fe29316476..bbd75a7cbbc4 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig

@@ -58,6 +58,7 @@ 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 8767e45f1b2b..3cc26d90ab82 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig

@@ -47,6 +47,7 @@ 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 ef9d403cbbe4..542bf49cdfcc 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig

@@ -4,6 +4,7 @@
 
 config TILE
 	def_bool y
+	select ARCH_32BIT_OFF_T if !64BIT
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_WANT_FRAME_POINTERS

diff --git a/arch/unicore32/Kconfig b/arch/unicore32/Kconfig
index 462e59a7ae78..34694eb7c790 100644
--- a/arch/unicore32/Kconfig
+++ b/arch/unicore32/Kconfig

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 config UNICORE32
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0fa71a78ec99..47c2f1eaa7ad 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig

@@ -44,6 +44,7 @@ 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_ACPI_TABLE_UPGRADE	if ACPI

diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig
index 13ed827c7c66..d1de823a8fe7 100644
--- a/arch/x86/um/Kconfig
+++ b/arch/x86/um/Kconfig

@@ -22,6 +22,7 @@ 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 c921e8bccdc8..20ebab4fbaf6 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig

@@ -4,6 +4,7 @@ config ZONE_DMA
 
 config XTENSA
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_NO_COHERENT_DMA_MMAP if !MMU
 	select ARCH_WANT_FRAME_POINTERS
 	select ARCH_WANT_IPC_PARSE_VERSION

diff --git a/include/linux/fcntl.h b/include/linux/fcntl.h
index 27dc7a60693e..d019df946cb2 100644
--- a/include/linux/fcntl.h
+++ b/include/linux/fcntl.h

@@ -12,7 +12,7 @@
 	 O_NOATIME | O_CLOEXEC | O_PATH | __O_TMPFILE)
 
 #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

-- 
2.17.0

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