32-bit userspace ABI: introduce ARCH_32BIT_OFF_T config option

hulk inclusion
category: feature
bugzilla: NA
CVE: NA
---------------------------

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, nios2, openrisc, 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: NYury Norov <ynorov@caviumnetworks.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>

 Conflicts:
	arch/x86/um/Kconfig
[wangxiongfeng: conflicts in arch/x86/um/Kconfig. We only need to add
'select ARCH_32BIT_OFF_T' and ignore others. ]
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: NHanjun Guo &lt;guohanjun@huawei.com <mailto:guohanjun@huawei.com&gt;>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/Kconfig

@@ -276,6 +276,21 @@ 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

arch/arc/Kconfig

@@ -14,6 +14,7 @@ config ARC
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	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

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

arch/h8300/Kconfig

 # 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

arch/hexagon/Kconfig

@@ -4,6 +4,7 @@ comment "Linux Kernel Configuration for Hexagon"
 
 config HEXAGON
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_NO_PREEMPT
 	select HAVE_OPROFILE
 	# Other pending projects/to-do items.

arch/m68k/Kconfig

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

arch/microblaze/Kconfig

 config MICROBLAZE
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_NO_SWAP
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_SYNC_DMA_FOR_CPU

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

arch/nds32/Kconfig

@@ -31,6 +31,7 @@ config NDS32
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_MEMBLOCK
 	select HAVE_REGS_AND_STACK_ACCESS_API
+	select ARCH_32BIT_OFF_T
 	select IRQ_DOMAIN
 	select LOCKDEP_SUPPORT
 	select MODULES_USE_ELF_RELA

arch/nios2/Kconfig

 # SPDX-License-Identifier: GPL-2.0
 config NIOS2
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_NO_SWAP

arch/openrisc/Kconfig

@@ -6,6 +6,7 @@
 
 config OPENRISC
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select DMA_NONCOHERENT_OPS
 	select OF

arch/parisc/Kconfig

 # 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

arch/powerpc/Kconfig

@@ -128,6 +128,7 @@ 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

arch/riscv/Kconfig

@@ -11,6 +11,7 @@ config 32BIT
 
 config RISCV
 	def_bool y
+	select ARCH_32BIT_OFF_T if !64BIT
 	# even on 32-bit, physical (and DMA) addresses are > 32-bits
 	select PHYS_ADDR_T_64BIT
 	select OF

arch/sh/Kconfig

@@ -61,6 +61,7 @@ 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

arch/sparc/Kconfig

@@ -50,6 +50,7 @@ config SPARC
 
 config SPARC32
 	def_bool !64BIT
+	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select DMA_NONCOHERENT_OPS
 	select GENERIC_ATOMIC64

arch/unicore32/Kconfig

 # 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

arch/x86/Kconfig

@@ -46,6 +46,7 @@ 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

arch/x86/um/Kconfig

@@ -16,6 +16,7 @@ config 64BIT
 
 config X86_32
 	def_bool !64BIT
+	select ARCH_32BIT_OFF_T
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select MODULES_USE_ELF_REL
 	select CLONE_BACKWARDS

arch/xtensa/Kconfig

@@ -4,6 +4,7 @@ config ZONE_DMA
 
 config XTENSA
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE

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