16 files changed, 31 insertions, 76 deletions

diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 0339181bf3ac..433e75a2ee9a 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -1,5 +1,6 @@
 config PARISC
         def_bool y
+        select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
         select HAVE_IDE
         select HAVE_OPROFILE
         select HAVE_FUNCTION_TRACER if 64BIT
diff --git a/arch/parisc/Kconfig.debug b/arch/parisc/Kconfig.debug
index 7305ac8f7f5b..bc989e522a04 100644
--- a/arch/parisc/Kconfig.debug
+++ b/arch/parisc/Kconfig.debug
@@ -12,18 +12,4 @@ config DEBUG_RODATA
          portion of the kernel code won't be covered by a TLB anymore.
          If in doubt, say "N".
 
-config DEBUG_STRICT_USER_COPY_CHECKS
-        bool "Strict copy size checks"
-        depends on DEBUG_KERNEL && !TRACE_BRANCH_PROFILING
-        ---help---
-          Enabling this option turns a certain set of sanity checks for user
-          copy operations into compile time failures.
-
-          The copy_from_user() etc checks are there to help test if there
-          are sufficient security checks on the length argument of
-          the copy operation, by having gcc prove that the argument is
-          within bounds.
-
-          If unsure, or if you run an older (pre 4.4) gcc, say N.
-
 endmenu
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index bda6ba6f3cf5..ce640aff61a1 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -91,6 +91,7 @@ config S390
         select ARCH_INLINE_WRITE_UNLOCK_BH
         select ARCH_INLINE_WRITE_UNLOCK_IRQ
         select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
+        select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
         select ARCH_SAVE_PAGE_KEYS if HIBERNATION
         select ARCH_WANT_IPC_PARSE_VERSION
         select BUILDTIME_EXTABLE_SORT
diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug
index fc32a2df4974..c56878e1245f 100644
--- a/arch/s390/Kconfig.debug
+++ b/arch/s390/Kconfig.debug
@@ -17,20 +17,6 @@ config STRICT_DEVMEM
 
           If you are unsure, say Y.
 
-config DEBUG_STRICT_USER_COPY_CHECKS
-        def_bool n
-        prompt "Strict user copy size checks"
-        ---help---
-          Enabling this option turns a certain set of sanity checks for user
-          copy operations into compile time warnings.
-
-          The copy_from_user() etc checks are there to help test if there
-          are sufficient security checks on the length argument of
-          the copy operation, by having gcc prove that the argument is
-          within bounds.
-
-          If unsure, or if you run an older (pre 4.4) gcc, say N.
-
 config S390_PTDUMP
         bool "Export kernel pagetable layout to userspace via debugfs"
         depends on DEBUG_KERNEL
diff --git a/arch/s390/lib/Makefile b/arch/s390/lib/Makefile
index 6ab0d0b5cec8..20b0e97a7df2 100644
--- a/arch/s390/lib/Makefile
+++ b/arch/s390/lib/Makefile
@@ -3,7 +3,6 @@
 #
 
 lib-y += delay.o string.o uaccess_std.o uaccess_pt.o
-obj-y += usercopy.o
 obj-$(CONFIG_32BIT) += div64.o qrnnd.o ucmpdi2.o mem32.o
 obj-$(CONFIG_64BIT) += mem64.o
 lib-$(CONFIG_64BIT) += uaccess_mvcos.o
diff --git a/arch/sparc/lib/Makefile b/arch/sparc/lib/Makefile
index 8410065f2862..dbe119b63b48 100644
--- a/arch/sparc/lib/Makefile
+++ b/arch/sparc/lib/Makefile
@@ -45,4 +45,3 @@ obj-y                 += iomap.o
 obj-$(CONFIG_SPARC32) += atomic32.o ucmpdi2.o
 obj-y                 += ksyms.o
 obj-$(CONFIG_SPARC64) += PeeCeeI.o
-obj-y                 += usercopy.o
diff --git a/arch/sparc/lib/usercopy.c b/arch/sparc/lib/usercopy.c
deleted file mode 100644
index 5c4284ce1c03..000000000000
--- a/arch/sparc/lib/usercopy.c
+++ /dev/null
@@ -1,9 +0,0 @@
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/bug.h>
-
-void copy_from_user_overflow(void)
-{
-        WARN(1, "Buffer overflow detected!\n");
-}
-EXPORT_SYMBOL(copy_from_user_overflow);
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 25877aebc685..0f712f4e1b33 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -19,6 +19,7 @@ config TILE
         select HAVE_SYSCALL_WRAPPERS if TILEGX
         select VIRT_TO_BUS
         select SYS_HYPERVISOR
+        select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
         select ARCH_HAVE_NMI_SAFE_CMPXCHG
         select GENERIC_CLOCKEVENTS
         select MODULES_USE_ELF_RELA
@@ -114,13 +115,6 @@ config STRICT_DEVMEM
 config SMP
         def_bool y
 
-# Allow checking for compile-time determined overflow errors in
-# copy_from_user().  There are still unprovable places in the
-# generic code as of 2.6.34, so this option is not really compatible
-# with -Werror, which is more useful in general.
-config DEBUG_COPY_FROM_USER
-        def_bool n
-
 config HVC_TILE
         depends on TTY
         select HVC_DRIVER
diff --git a/arch/tile/include/asm/uaccess.h b/arch/tile/include/asm/uaccess.h
index 9ab078a4605d..8a082bc6bca5 100644
--- a/arch/tile/include/asm/uaccess.h
+++ b/arch/tile/include/asm/uaccess.h
@@ -395,7 +395,12 @@ _copy_from_user(void *to, const void __user *from, unsigned long n)
         return n;
 }
 
-#ifdef CONFIG_DEBUG_COPY_FROM_USER
+#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
+/*
+ * There are still unprovable places in the generic code as of 2.6.34, so this
+ * option is not really compatible with -Werror, which is more useful in
+ * general.
+ */
 extern void copy_from_user_overflow(void)
         __compiletime_warning("copy_from_user() size is not provably correct");
 
diff --git a/arch/tile/lib/uaccess.c b/arch/tile/lib/uaccess.c
index f8d398c9ee7f..030abe3ee4f1 100644
--- a/arch/tile/lib/uaccess.c
+++ b/arch/tile/lib/uaccess.c
@@ -22,11 +22,3 @@ int __range_ok(unsigned long addr, unsigned long size)
                  is_arch_mappable_range(addr, size));
 }
 EXPORT_SYMBOL(__range_ok);
-
-#ifdef CONFIG_DEBUG_COPY_FROM_USER
-void copy_from_user_overflow(void)
-{
-       WARN(1, "Buffer overflow detected!\n");
-}
-EXPORT_SYMBOL(copy_from_user_overflow);
-#endif
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 05b057dca4a7..5db2117ae288 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -20,6 +20,7 @@ config X86_64
 ### Arch settings
 config X86
         def_bool y
+        select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
         select HAVE_AOUT if X86_32
         select HAVE_UNSTABLE_SCHED_CLOCK
         select ARCH_SUPPORTS_NUMA_BALANCING
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 16f738385dcb..c198b7e13e7b 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -292,20 +292,6 @@ config OPTIMIZE_INLINING
 
           If unsure, say N.
 
-config DEBUG_STRICT_USER_COPY_CHECKS
-        bool "Strict copy size checks"
-        depends on DEBUG_KERNEL && !TRACE_BRANCH_PROFILING
-        ---help---
-          Enabling this option turns a certain set of sanity checks for user
-          copy operations into compile time failures.
-
-          The copy_from_user() etc checks are there to help test if there
-          are sufficient security checks on the length argument of
-          the copy operation, by having gcc prove that the argument is
-          within bounds.
-
-          If unsure, or if you run an older (pre 4.4) gcc, say N.
-
 config DEBUG_NMI_SELFTEST
         bool "NMI Selftest"
         depends on DEBUG_KERNEL && X86_LOCAL_APIC
diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
index f0312d746402..3eb18acd0e40 100644
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -689,9 +689,3 @@ _copy_from_user(void *to, const void __user *from, unsigned long n)
         return n;
 }
 EXPORT_SYMBOL(_copy_from_user);
-
-void copy_from_user_overflow(void)
-{
-        WARN(1, "Buffer overflow detected!\n");
-}
-EXPORT_SYMBOL(copy_from_user_overflow);
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 77ebaa3dfa12..770a422a42e8 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1292,6 +1292,24 @@ config LATENCYTOP
           Enable this option if you want to use the LatencyTOP tool
           to find out which userspace is blocking on what kernel operations.
 
+config ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
+        bool
+
+config DEBUG_STRICT_USER_COPY_CHECKS
+        bool "Strict user copy size checks"
+        depends on ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
+        depends on DEBUG_KERNEL && !TRACE_BRANCH_PROFILING
+        help
+          Enabling this option turns a certain set of sanity checks for user
+          copy operations into compile time failures.
+
+          The copy_from_user() etc checks are there to help test if there
+          are sufficient security checks on the length argument of
+          the copy operation, by having gcc prove that the argument is
+          within bounds.
+
+          If unsure, say N.
+
 source mm/Kconfig.debug
 source kernel/trace/Kconfig
 
diff --git a/lib/Makefile b/lib/Makefile
index 23c9a0fe74fc..e9c52e1b853a 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -15,6 +15,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
          is_single_threaded.o plist.o decompress.o kobject_uevent.o \
          earlycpio.o
 
+obj-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o
 lib-$(CONFIG_MMU) += ioremap.o
 lib-$(CONFIG_SMP) += cpumask.o
 
diff --git a/arch/s390/lib/usercopy.c b/lib/usercopy.c
index 14b363fec8a2..4f5b1ddbcd25 100644
--- a/arch/s390/lib/usercopy.c
+++ b/lib/usercopy.c
@@ -1,5 +1,6 @@
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/bug.h>
+#include <linux/uaccess.h>
 
 void copy_from_user_overflow(void)
 {