The patch titled
Subject: Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
has been added to the -mm tree. Its filename is
kconfig-consolidate-config_debug_strict_user_copy_checks.patch
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------------------------------------------------------
From: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Subject: Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
The help text for this config is duplicated across the x86, parisc, and
s390 Kconfig.debug files. Arnd Bergman noted that the help text was
slightly misleading and should be fixed to state that enabling this option
isn't a problem when using pre 4.4 gcc.
To simplify the rewording, consolidate the text into lib/Kconfig.debug and
modify it there to be more explicit about when you should say N to this
config.
Also, make the text a bit more generic by stating that this option enables
compile time checks so we can cover architectures which emit warnings vs.
ones which emit errors. The details of how an architecture decided to
implement the checks isn't as important as the concept of compile time
checking of copy_from_user() calls.
While we're doing this, remove all the copy_from_user_overflow() code
that's duplicated many times and place it into lib/ so that any
architecture supporting this option can get the function for free.
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Acked-by: Helge Deller <deller@xxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Cc: Chris Metcalf <cmetcalf@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/parisc/Kconfig | 1 +
arch/parisc/Kconfig.debug | 14 --------------
arch/s390/Kconfig | 1 +
arch/s390/Kconfig.debug | 14 --------------
arch/s390/lib/Makefile | 1 -
arch/s390/lib/usercopy.c | 8 --------
arch/sparc/lib/Makefile | 1 -
arch/sparc/lib/usercopy.c | 9 ---------
arch/tile/Kconfig | 8 +-------
arch/tile/include/asm/uaccess.h | 7 ++++++-
arch/tile/lib/uaccess.c | 8 --------
arch/x86/Kconfig | 1 +
arch/x86/Kconfig.debug | 14 --------------
arch/x86/lib/usercopy_32.c | 6 ------
lib/Kconfig.debug | 18 ++++++++++++++++++
lib/Makefile | 1 +
lib/usercopy.c | 9 +++++++++
17 files changed, 38 insertions(+), 83 deletions(-)
diff -puN arch/parisc/Kconfig~kconfig-consolidate-config_debug_strict_user_copy_checks arch/parisc/Kconfig
--- a/arch/parisc/Kconfig~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/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 -puN arch/parisc/Kconfig.debug~kconfig-consolidate-config_debug_strict_user_copy_checks arch/parisc/Kconfig.debug
--- a/arch/parisc/Kconfig.debug~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/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 -puN arch/s390/Kconfig~kconfig-consolidate-config_debug_strict_user_copy_checks arch/s390/Kconfig
--- a/arch/s390/Kconfig~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/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 -puN arch/s390/Kconfig.debug~kconfig-consolidate-config_debug_strict_user_copy_checks arch/s390/Kconfig.debug
--- a/arch/s390/Kconfig.debug~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/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 -puN arch/s390/lib/Makefile~kconfig-consolidate-config_debug_strict_user_copy_checks arch/s390/lib/Makefile
--- a/arch/s390/lib/Makefile~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/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-$(CONFIG_64BIT) += uaccess_mvcos.o
diff -puN arch/s390/lib/usercopy.c~kconfig-consolidate-config_debug_strict_user_copy_checks /dev/null
--- a/arch/s390/lib/usercopy.c
+++ /dev/null
@@ -1,8 +0,0 @@
-#include <linux/module.h>
-#include <linux/bug.h>
-
-void copy_from_user_overflow(void)
-{
- WARN(1, "Buffer overflow detected!\n");
-}
-EXPORT_SYMBOL(copy_from_user_overflow);
diff -puN arch/sparc/lib/Makefile~kconfig-consolidate-config_debug_strict_user_copy_checks arch/sparc/lib/Makefile
--- a/arch/sparc/lib/Makefile~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/arch/sparc/lib/Makefile
@@ -45,4 +45,3 @@ obj-y += iomap.o
obj-$(CONFIG_SPARC32) += atomic32.o ucmpdi2.o
obj-y += ksyms.o
obj-$(CONFIG_SPARC64) += PeeCeeI.o
-obj-y += usercopy.o
diff -puN arch/sparc/lib/usercopy.c~kconfig-consolidate-config_debug_strict_user_copy_checks /dev/null
--- 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 -puN arch/tile/Kconfig~kconfig-consolidate-config_debug_strict_user_copy_checks arch/tile/Kconfig
--- a/arch/tile/Kconfig~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/arch/tile/Kconfig
@@ -19,6 +19,7 @@ config TILE
select HAVE_SYSCALL_WRAPPERS if TILEGX
select HAVE_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
@@ -117,13 +118,6 @@ 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 -puN arch/tile/include/asm/uaccess.h~kconfig-consolidate-config_debug_strict_user_copy_checks arch/tile/include/asm/uaccess.h
--- a/arch/tile/include/asm/uaccess.h~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/arch/tile/include/asm/uaccess.h
@@ -395,7 +395,12 @@ _copy_from_user(void *to, const void __u
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 -puN arch/tile/lib/uaccess.c~kconfig-consolidate-config_debug_strict_user_copy_checks arch/tile/lib/uaccess.c
--- a/arch/tile/lib/uaccess.c~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/arch/tile/lib/uaccess.c
@@ -22,11 +22,3 @@ int __range_ok(unsigned long addr, unsig
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 -puN arch/x86/Kconfig~kconfig-consolidate-config_debug_strict_user_copy_checks arch/x86/Kconfig
--- a/arch/x86/Kconfig~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/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 -puN arch/x86/Kconfig.debug~kconfig-consolidate-config_debug_strict_user_copy_checks arch/x86/Kconfig.debug
--- a/arch/x86/Kconfig.debug~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/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 -puN arch/x86/lib/usercopy_32.c~kconfig-consolidate-config_debug_strict_user_copy_checks arch/x86/lib/usercopy_32.c
--- a/arch/x86/lib/usercopy_32.c~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/arch/x86/lib/usercopy_32.c
@@ -689,9 +689,3 @@ _copy_from_user(void *to, const void __u
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 -puN lib/Kconfig.debug~kconfig-consolidate-config_debug_strict_user_copy_checks lib/Kconfig.debug
--- a/lib/Kconfig.debug~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/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 -puN lib/Makefile~kconfig-consolidate-config_debug_strict_user_copy_checks lib/Makefile
--- a/lib/Makefile~kconfig-consolidate-config_debug_strict_user_copy_checks
+++ a/lib/Makefile
@@ -15,6 +15,7 @@ lib-y := ctype.o string.o vsprintf.o cmd
is_single_threaded.o plist.o decompress.o kobject_uevent.o \
earlycpio.o percpu-refcount.o
+lib-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o
lib-$(CONFIG_MMU) += ioremap.o
lib-$(CONFIG_SMP) += cpumask.o
diff -puN /dev/null lib/usercopy.c
--- /dev/null
+++ a/lib/usercopy.c
@@ -0,0 +1,9 @@
+#include <linux/export.h>
+#include <linux/bug.h>
+#include <linux/uaccess.h>
+
+void copy_from_user_overflow(void)
+{
+ WARN(1, "Buffer overflow detected!\n");
+}
+EXPORT_SYMBOL(copy_from_user_overflow);
_
Patches currently in -mm which might be from sboyd@xxxxxxxxxxxxxx are
origin.patch
timer_list-split-timer_list_show_tickdevices-v4.patch
timer_list-convert-timer-list-to-be-a-proper-seq_file-v3.patch
timer_list-convert-timer-list-to-be-a-proper-seq_file-v3-fix.patch
kconfig-consolidate-config_debug_strict_user_copy_checks.patch
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