[PATCH 2/3] 32-bit userspace ABI: introduce ARCH_32BIT_OFF_T config option

From: Yury Norov
Date: Mon Sep 25 2017 - 17:01:23 EST

All new 32-bit architectures should have 64-bit userspace 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 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 <ynorov@xxxxxxxxxxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
---
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 e02d07ca9c50..88bf4d1af1f2 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -249,6 +249,21 @@ 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 a598641eed98..a2560dec14ff 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 7888c9803eb0..b848d4bd8292 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_CLOCKSOURCE_DATA
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEVMEM_IS_ALLOWED
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 89bdb8264305..e8de6acf7493 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 71b758dc3a96..8c059f07ddb6 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 1cce8243449e..428d5d6f0197 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 3089f7fe2abd..180f576542d5 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 1941e4baaee6..bbcea8c33e44 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 87cde1e4b38c..19805316e808 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 353d90487c2b..78ee42ca616b 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 ARCH_NO_COHERENT_DMA_MMAP if !MMU
select HAVE_IDE
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index 7d8b322e5101..9b7d12ceca18 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 9d26abdf0dc1..55945abdc8e9 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 cb7fcc4216fd..c543005baed7 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_BINFMT_ELF_STATE
select ARCH_CLOCKSOURCE_DATA
select ARCH_DISCARD_MEMBLOCK
diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig
index 38e3494bfb63..75f226e6e819 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_EXIT_THREAD
select HAVE_OPROFILE
select HAVE_UID16
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index c587764b9c5a..aafa81ea6e0b 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -1,5 +1,6 @@
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 a0f2e4a323c1..2b56b8011d19 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 bb8ed34024ef..ab07a37c183e 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_MIGHT_HAVE_PC_PARPORT
select HAVE_IDE
select HAVE_OPROFILE
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 809c468edab1..78f269b9db7e 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -133,6 +133,7 @@ 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 507d63181389..0a9484bbddf5 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 640a85925060..2ee30af2e866 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -57,6 +57,7 @@ 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 0be3828752e5..09e02b616367 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -48,6 +48,7 @@ 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 4583c0320059..845dcbd8235e 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 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 0a3bfd1fefcd..9629fd827d6b 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_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 0fb8790a5932..06455fde2afb 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -43,6 +43,7 @@ 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 ed56a1c4ae73..8436bcd9beba 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 7ad6d77b2f22..aa39c680ce75 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_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 1b48d9c9a561..297993c92490 100644
--- a/include/linux/fcntl.h
+++ b/include/linux/fcntl.h
@@ -11,7 +11,7 @@
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
--
2.11.0