The patch titled
Consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
has been added to the -mm tree. Its filename is
consolidate-config_debug_strict_user_copy_checks.patch
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------------------------------------------------------
Subject: Consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
From: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
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>
Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
Acked-by: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Acked-by: 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 | 8 --------
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 ------
arch/x86/lib/usercopy_64.c | 6 ------
lib/Kconfig.debug | 18 ++++++++++++++++++
lib/Makefile | 1 +
lib/usercopy.c | 8 ++++++++
18 files changed, 37 insertions(+), 88 deletions(-)
diff -puN arch/parisc/Kconfig~consolidate-config_debug_strict_user_copy_checks arch/parisc/Kconfig
--- a/arch/parisc/Kconfig~consolidate-config_debug_strict_user_copy_checks
+++ a/arch/parisc/Kconfig
@@ -15,6 +15,7 @@ config PARISC
select HAVE_GENERIC_HARDIRQS
select GENERIC_IRQ_PROBE
select IRQ_PER_CPU
+ select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
help
The PA-RISC microprocessor is designed by Hewlett-Packard and used
diff -puN arch/parisc/Kconfig.debug~consolidate-config_debug_strict_user_copy_checks arch/parisc/Kconfig.debug
--- a/arch/parisc/Kconfig.debug~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~consolidate-config_debug_strict_user_copy_checks arch/s390/Kconfig
--- a/arch/s390/Kconfig~consolidate-config_debug_strict_user_copy_checks
+++ a/arch/s390/Kconfig
@@ -118,6 +118,7 @@ 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
config SCHED_OMIT_FRAME_POINTER
def_bool y
diff -puN arch/s390/Kconfig.debug~consolidate-config_debug_strict_user_copy_checks arch/s390/Kconfig.debug
--- a/arch/s390/Kconfig.debug~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 DEBUG_SET_MODULE_RONX
def_bool y
depends on MODULES
diff -puN arch/s390/lib/Makefile~consolidate-config_debug_strict_user_copy_checks arch/s390/lib/Makefile
--- a/arch/s390/lib/Makefile~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-$(CONFIG_32BIT) += div64.o qrnnd.o ucmpdi2.o
lib-$(CONFIG_64BIT) += uaccess_mvcos.o
lib-$(CONFIG_SMP) += spinlock.o
diff -puN arch/s390/lib/usercopy.c~consolidate-config_debug_strict_user_copy_checks /dev/null
--- a/arch/s390/lib/usercopy.c
+++ /dev/null
@@ -1,8 +0,0 @@
-#include <linux/module.h>
-#include <linux/bug.h>
-
-void copy_from_user_overflow(void)
-{
- WARN(1, "Buffer overflow detected!\n");
-}
-EXPORT_SYMBOL(copy_from_user_overflow);
diff -puN arch/sparc/lib/Makefile~consolidate-config_debug_strict_user_copy_checks arch/sparc/lib/Makefile
--- a/arch/sparc/lib/Makefile~consolidate-config_debug_strict_user_copy_checks
+++ a/arch/sparc/lib/Makefile
@@ -43,4 +43,3 @@ obj-y += iomap.o
obj-$(CONFIG_SPARC32) += atomic32.o
obj-y += ksyms.o
obj-$(CONFIG_SPARC64) += PeeCeeI.o
-obj-y += usercopy.o
diff -puN arch/sparc/lib/usercopy.c~consolidate-config_debug_strict_user_copy_checks /dev/null
--- a/arch/sparc/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/tile/Kconfig~consolidate-config_debug_strict_user_copy_checks arch/tile/Kconfig
--- a/arch/tile/Kconfig~consolidate-config_debug_strict_user_copy_checks
+++ a/arch/tile/Kconfig
@@ -12,6 +12,7 @@ config TILE
select GENERIC_PENDING_IRQ if SMP
select GENERIC_IRQ_SHOW
select SYS_HYPERVISOR
+ select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
# FIXME: investigate whether we need/want these options.
# select HAVE_IOREMAP_PROT
@@ -96,13 +97,6 @@ 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
select HVC_DRIVER
def_bool y
diff -puN arch/tile/include/asm/uaccess.h~consolidate-config_debug_strict_user_copy_checks arch/tile/include/asm/uaccess.h
--- a/arch/tile/include/asm/uaccess.h~consolidate-config_debug_strict_user_copy_checks
+++ a/arch/tile/include/asm/uaccess.h
@@ -353,7 +353,12 @@ _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~consolidate-config_debug_strict_user_copy_checks arch/tile/lib/uaccess.c
--- a/arch/tile/lib/uaccess.c~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~consolidate-config_debug_strict_user_copy_checks arch/x86/Kconfig
--- a/arch/x86/Kconfig~consolidate-config_debug_strict_user_copy_checks
+++ a/arch/x86/Kconfig
@@ -70,6 +70,7 @@ config X86
select IRQ_FORCED_THREADING
select USE_GENERIC_SMP_HELPERS if SMP
select HAVE_BPF_JIT if (X86_64 && NET)
+ select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
config INSTRUCTION_DECODER
def_bool (KPROBES || PERF_EVENTS)
diff -puN arch/x86/Kconfig.debug~consolidate-config_debug_strict_user_copy_checks arch/x86/Kconfig.debug
--- a/arch/x86/Kconfig.debug~consolidate-config_debug_strict_user_copy_checks
+++ a/arch/x86/Kconfig.debug
@@ -270,18 +270,4 @@ 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.
-
endmenu
diff -puN arch/x86/lib/usercopy_32.c~consolidate-config_debug_strict_user_copy_checks arch/x86/lib/usercopy_32.c
--- a/arch/x86/lib/usercopy_32.c~consolidate-config_debug_strict_user_copy_checks
+++ a/arch/x86/lib/usercopy_32.c
@@ -883,9 +883,3 @@ _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 arch/x86/lib/usercopy_64.c~consolidate-config_debug_strict_user_copy_checks arch/x86/lib/usercopy_64.c
--- a/arch/x86/lib/usercopy_64.c~consolidate-config_debug_strict_user_copy_checks
+++ a/arch/x86/lib/usercopy_64.c
@@ -181,9 +181,3 @@ copy_user_handle_tail(char *to, char *fr
break;
return len;
}
-
-void copy_from_user_overflow(void)
-{
- WARN(1, "Buffer overflow detected!\n");
-}
-EXPORT_SYMBOL(copy_from_user_overflow);
diff -puN lib/Kconfig.debug~consolidate-config_debug_strict_user_copy_checks lib/Kconfig.debug
--- a/lib/Kconfig.debug~consolidate-config_debug_strict_user_copy_checks
+++ a/lib/Kconfig.debug
@@ -1106,6 +1106,24 @@ config SYSCTL_SYSCALL_CHECK
to properly maintain and use. This enables checks that help
you to keep things correct.
+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~consolidate-config_debug_strict_user_copy_checks lib/Makefile
--- a/lib/Makefile~consolidate-config_debug_strict_user_copy_checks
+++ a/lib/Makefile
@@ -14,6 +14,7 @@ lib-y := ctype.o string.o vsprintf.o cmd
proportions.o prio_heap.o ratelimit.o show_mem.o \
is_single_threaded.o plist.o decompress.o find_next_bit.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 +1,8 @@
+#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);
_
Patches currently in -mm which might be from sboyd@xxxxxxxxxxxxxx are
linux-next.patch
lpfc-silence-debug_strict_user_copy_checks=y-warning.patch
kprobes-silence-debug_strict_user_copy_checks=y-warning.patch
x86-implement-strict-user-copy-checks-for-x86_64.patch
consolidate-config_debug_strict_user_copy_checks.patch
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