asm-generic: reverse GENERIC_{STRNCPY_FROM,STRNLEN}_USER symbols

arndb · arndb · commit e6226997ec5a · 2021-07-30T10:30:21.000+02:00
Most architectures do not need a custom implementation, and in most
cases the generic implementation is preferred, so change the polariy
on these Kconfig symbols to require architectures to select them when
they provide their own version.

The new name is CONFIG_ARCH_HAS_{STRNCPY_FROM,STRNLEN}_USER.

The remaining architectures at the moment are: ia64, mips, parisc,
um and xtensa. We should probably convert these as well, but
I was not sure how far to take this series. Thomas Bogendoerfer
had some concerns about converting mips but may still do some
more detailed measurements to see which version is better.

Cc: "James E.J. Bottomley" &lt;James.Bottomley@HansenPartnership.com&gt;
Cc: Anton Ivanov &lt;anton.ivanov@cambridgegreys.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Acked-by: Helge Deller &lt;deller@gmx.de&gt; # parisc
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
@@ -29,8 +29,6 @@ config ALPHA
 	select AUDIT_ARCH
 	select GENERIC_CPU_VULNERABILITIES
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
@@ -27,8 +27,6 @@ config ARC
 	select GENERIC_PENDING_IRQ if SMP
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARC_MMU_V4
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
@@ -63,8 +63,6 @@ config ARM
 	select GENERIC_PCI_IOMAP
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
@@ -130,8 +130,6 @@ config ARM64
 	select GENERIC_PTDUMP
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
 	select GENERIC_VDSO_TIME_NS
diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
@@ -35,8 +35,6 @@ config CSKY
 	select GENERIC_IRQ_MULTI_HANDLER
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_VDSO_32
 	select GENERIC_GETTIMEOFDAY
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
@@ -11,8 +11,6 @@ config H8300
 	select GENERIC_IRQ_SHOW
 	select FRAME_POINTER
 	select GENERIC_CPU_DEVICES
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select MODULES_USE_ELF_RELA
 	select COMMON_CLK
 	select ARCH_WANT_FRAME_POINTERS
diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
@@ -19,8 +19,6 @@ config HEXAGON
 	# GENERIC_ALLOCATOR is used by dma_alloc_coherent()
 	select GENERIC_ALLOCATOR
 	select GENERIC_IRQ_SHOW
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_TRACEHOOK
 	select NEED_SG_DMA_LENGTH
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
@@ -9,6 +9,8 @@ menu "Processor type and features"
 config IA64
 	bool
 	select ARCH_HAS_DMA_MARK_CLEAN
+	select ARCH_HAS_STRNCPY_FROM_USER
+	select ARCH_HAS_STRNLEN_USER
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
 	select ACPI
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
@@ -16,8 +16,6 @@ config M68K
 	select GENERIC_CPU_DEVICES
 	select GENERIC_IOMAP
 	select GENERIC_IRQ_SHOW
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select HAVE_AOUT if MMU
 	select HAVE_ASM_MODVERSIONS
 	select HAVE_DEBUG_BUGVERBOSE
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
@@ -21,8 +21,6 @@ config MICROBLAZE
 	select GENERIC_IRQ_SHOW
 	select GENERIC_PCI_IOMAP
 	select GENERIC_SCHED_CLOCK
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select HAVE_ARCH_HASH
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_SECCOMP
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
@@ -9,6 +9,8 @@ config MIPS
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE if !EVA
 	select ARCH_HAS_PTE_SPECIAL if !(32BIT && CPU_HAS_RIXI)
+	select ARCH_HAS_STRNCPY_FROM_USER
+	select ARCH_HAS_STRNLEN_USER
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
 	select ARCH_HAS_GCOV_PROFILE_ALL
diff --git a/arch/nds32/Kconfig b/arch/nds32/Kconfig
@@ -26,8 +26,6 @@ config NDS32
 	select GENERIC_LIB_LSHRDI3
 	select GENERIC_LIB_MULDI3
 	select GENERIC_LIB_UCMPDI2
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select HANDLE_DOMAIN_IRQ
 	select HAVE_ARCH_TRACEHOOK
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
@@ -13,8 +13,6 @@ config NIOS2
 	select GENERIC_CPU_DEVICES
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_ARCH_KGDB
 	select IRQ_DOMAIN
diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
@@ -25,8 +25,6 @@ config OPENRISC
 	select HAVE_UID16
 	select GENERIC_ATOMIC64
 	select GENERIC_CLOCKEVENTS_BROADCAST
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select GENERIC_SMP_IDLE_THREAD
 	select MODULES_USE_ELF_RELA
 	select HAVE_DEBUG_STACKOVERFLOW
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
@@ -11,6 +11,7 @@ config PARISC
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_STRICT_KERNEL_RWX
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
+	select ARCH_HAS_STRNLEN_USER
 	select ARCH_NO_SG_CHAIN
 	select ARCH_SUPPORTS_HUGETLBFS if PA20
 	select ARCH_SUPPORTS_MEMORY_FAILURE
@@ -34,7 +35,6 @@ config PARISC
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_CPU_DEVICES
-	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_LIB_DEVMEM_IS_ALLOWED
 	select SYSCTL_ARCH_UNALIGN_ALLOW
 	select SYSCTL_EXCEPTION_TRACE
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
@@ -183,8 +183,6 @@ config PPC
 	select GENERIC_IRQ_SHOW_LEVEL
 	select GENERIC_PCI_IOMAP		if PCI
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_VDSO_TIME_NS
 	select HAVE_ARCH_AUDITSYSCALL
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
@@ -56,8 +56,6 @@ config RISCV
 	select GENERIC_PTDUMP if MMU
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
 	select HANDLE_DOMAIN_IRQ
 	select HAVE_ARCH_AUDITSYSCALL
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
@@ -130,8 +130,6 @@ config S390
 	select GENERIC_GETTIMEOFDAY
 	select GENERIC_PTDUMP
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_VDSO_TIME_NS
 	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
@@ -22,8 +22,6 @@ config SUPERH
 	select GENERIC_IRQ_SHOW
 	select GENERIC_PCI_IOMAP if PCI
 	select GENERIC_SCHED_CLOCK
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select GENERIC_SMP_IDLE_THREAD
 	select GUP_GET_PTE_LOW_HIGH if X2TLB
 	select HAVE_ARCH_AUDITSYSCALL
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
@@ -38,8 +38,6 @@ config SPARC
 	select HAVE_EBPF_JIT if SPARC64
 	select HAVE_DEBUG_BUGVERBOSE
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select MODULES_USE_ELF_RELA
 	select PCI_SYSCALL if PCI
 	select PCI_MSI_ARCH_FALLBACKS if PCI_MSI
diff --git a/arch/um/Kconfig b/arch/um/Kconfig
@@ -7,6 +7,8 @@ config UML
 	default y
 	select ARCH_EPHEMERAL_INODES
 	select ARCH_HAS_KCOV
+	select ARCH_HAS_STRNCPY_FROM_USER
+	select ARCH_HAS_STRNLEN_USER
 	select ARCH_NO_PREEMPT
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_SECCOMP_FILTER
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
@@ -144,8 +144,6 @@ config X86
 	select GENERIC_PENDING_IRQ		if SMP
 	select GENERIC_PTDUMP
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
 	select GENERIC_VDSO_TIME_NS
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
@@ -7,6 +7,8 @@ config XTENSA
 	select ARCH_HAS_SYNC_DMA_FOR_CPU if MMU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE if MMU
 	select ARCH_HAS_DMA_SET_UNCACHED if MMU
+	select ARCH_HAS_STRNCPY_FROM_USER if !KASAN
+	select ARCH_HAS_STRNLEN_USER
 	select ARCH_USE_MEMTEST
 	select ARCH_USE_QUEUED_RWLOCKS
 	select ARCH_USE_QUEUED_SPINLOCKS
@@ -20,7 +22,6 @@ config XTENSA
 	select GENERIC_IRQ_SHOW
 	select GENERIC_PCI_IOMAP
 	select GENERIC_SCHED_CLOCK
-	select GENERIC_STRNCPY_FROM_USER if KASAN
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
 	select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
diff --git a/arch/xtensa/include/asm/uaccess.h b/arch/xtensa/include/asm/uaccess.h
@@ -290,8 +290,7 @@ clear_user(void __user *addr, unsigned long size)
 #define __clear_user  __xtensa_clear_user
 
 
-#ifndef CONFIG_GENERIC_STRNCPY_FROM_USER
-
+#ifdef CONFIG_ARCH_HAS_STRNCPY_FROM_USER
 extern long __strncpy_user(char *dst, const char __user *src, long count);
 
 static inline long
diff --git a/arch/xtensa/kernel/xtensa_ksyms.c b/arch/xtensa/kernel/xtensa_ksyms.c
@@ -43,7 +43,7 @@ EXPORT_SYMBOL(memmove);
 EXPORT_SYMBOL(__memset);
 EXPORT_SYMBOL(__memcpy);
 EXPORT_SYMBOL(__memmove);
-#ifndef CONFIG_GENERIC_STRNCPY_FROM_USER
+#ifdef CONFIG_ARCH_HAS_STRNCPY_FROM_USER
 EXPORT_SYMBOL(__strncpy_user);
 #endif
 EXPORT_SYMBOL(clear_page);
diff --git a/lib/Kconfig b/lib/Kconfig
@@ -50,12 +50,18 @@ config HAVE_ARCH_BITREVERSE
 	  This option enables the use of hardware bit-reversal instructions on
 	  architectures which support such operations.
 
-config GENERIC_STRNCPY_FROM_USER
+config ARCH_HAS_STRNCPY_FROM_USER
 	bool
 
-config GENERIC_STRNLEN_USER
+config ARCH_HAS_STRNLEN_USER
 	bool
 
+config GENERIC_STRNCPY_FROM_USER
+	def_bool !ARCH_HAS_STRNCPY_FROM_USER
+
+config GENERIC_STRNLEN_USER
+	def_bool !ARCH_HAS_STRNLEN_USER
+
 config GENERIC_NET_UTILS
 	bool
 
