[PATCH 2/8] 32-bit userspace ABI: introduce ARCH_32BIT_OFF_T config option

From: Arnd Bergmann <arnd@arndb.de>
Date: 2019-02-18 21:08:45
Also in: linux-arch, linux-arm-kernel, linux-riscv, lkml
Subsystem: arm port, c-sky architecture, 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, risc-v 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, Guo Ren, 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, Paul Walmsley, Palmer Dabbelt, Albert Ou, "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

From: Yury Norov <redacted>

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: Yury Norov <redacted>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Yury Norov <redacted>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/Kconfig            | 15 +++++++++++++++
 arch/arc/Kconfig        |  1 +
 arch/arm/Kconfig        |  1 +
 arch/c6x/Kconfig        |  1 +
 arch/csky/Kconfig       |  1 +
 arch/h8300/Kconfig      |  1 +
 arch/hexagon/Kconfig    |  1 +
 arch/m68k/Kconfig       |  1 +
 arch/microblaze/Kconfig |  1 +
 arch/mips/Kconfig       |  1 +
 arch/nds32/Kconfig      |  1 +
 arch/nios2/Kconfig      |  1 +
 arch/openrisc/Kconfig   |  1 +
 arch/parisc/Kconfig     |  1 +
 arch/powerpc/Kconfig    |  1 +
 arch/riscv/Kconfig      |  1 +
 arch/sh/Kconfig         |  1 +
 arch/sparc/Kconfig      |  1 +
 arch/unicore32/Kconfig  |  1 +
 arch/x86/Kconfig        |  1 +
 arch/x86/um/Kconfig     |  1 +
 arch/xtensa/Kconfig     |  1 +
 include/linux/fcntl.h   |  2 +-
 23 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index 46db715a7f42..89fe3d651349 100644
--- a/arch/Kconfig
+++ b/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

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 376366a7db81..1cfe4197146f 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig

@@ -14,6 +14,7 @@ config ARC
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	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 664e918e2624..8933f7337e56 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/c6x/Kconfig b/arch/c6x/Kconfig
index 456e154674d1..e5cd3c5f8399 100644
--- a/arch/c6x/Kconfig
+++ b/arch/c6x/Kconfig

@@ -6,6 +6,7 @@
 
 config C6X
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select CLKDEV_LOOKUP

diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index 398113c845f5..6959e0b1e956 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig

@@ -1,5 +1,6 @@
 config CSKY
 	def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_USE_BUILTIN_BSWAP

diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 6472a0685470..c071da34e081 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 fb2fbfcfc532..ac441680dcc0 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 ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_NO_PREEMPT
 	select HAVE_OPROFILE

diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index e173ea2ff395..b54206408f91 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_HAS_SYNC_DMA_FOR_DEVICE if HAS_DMA
 	select ARCH_MIGHT_HAVE_PC_PARPORT if ISA
 	select ARCH_NO_COHERENT_DMA_MMAP if !MMU

diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 58aff2653d86..a51b965b3b82 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_NO_SWAP
 	select ARCH_HAS_DMA_COHERENT_TO_PFN if MMU
 	select ARCH_HAS_GCOV_PROFILE_ALL

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 787290781b8c..d80ccabd3c06 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 if MIPS_FP_SUPPORT
 	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_DISCARD_MEMBLOCK

diff --git a/arch/nds32/Kconfig b/arch/nds32/Kconfig
index dda1906bba11..addb7f5f5264 100644
--- a/arch/nds32/Kconfig
+++ b/arch/nds32/Kconfig

@@ -5,6 +5,7 @@
 
 config NDS32
         def_bool y
+	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_WANT_FRAME_POINTERS if FTRACE

diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index 532343eebf89..c3e913ef4f0c 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 ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_NO_SWAP

diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 09ab59e942ae..a5e361fbb75a 100644
--- a/arch/openrisc/Kconfig
+++ b/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 OF
 	select OF_EARLY_FLATTREE

diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 7ca2c3ebad64..c8e621296092 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 2890d36eb531..375d0dc0dc7d 100644
--- a/arch/powerpc/Kconfig
+++ b/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_DEBUG_VIRTUAL
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_SET_COHERENT_MASK

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index feeeaa60697c..09fa3a87bf30 100644
--- a/arch/riscv/Kconfig
+++ b/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

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index a9c36f95744a..d9a9144dec35 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig

@@ -62,6 +62,7 @@ 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 d5dd652fb8cc..40f8f4f73fe8 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig

@@ -49,6 +49,7 @@ config SPARC
 
 config SPARC32
 	def_bool !64BIT
+	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select GENERIC_ATOMIC64
 	select CLZ_TAB

diff --git a/arch/unicore32/Kconfig b/arch/unicore32/Kconfig
index c3a41bfe161b..a7f1ae58d211 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 15af091611e2..7aac274c2849 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig

@@ -47,6 +47,7 @@ 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_CLOCKSOURCE_INIT
 	select ARCH_DISCARD_MEMBLOCK

diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig
index f518b4744ff8..ab14e6f73ca4 100644
--- a/arch/x86/um/Kconfig
+++ b/arch/x86/um/Kconfig

@@ -17,6 +17,7 @@ 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 20a0756f27ef..2033b4485cc4 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 config XTENSA
 	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_COHERENT_DMA_MMAP if !MMU

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

-- 
2.20.0

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