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

From: Arnd Bergmann
Date: Mon Feb 18 2019 - 16:08:43 EST

From: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx>

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 <ynorov@xxxxxxxxxxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
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