[GIT PULL] x86/asm for v2.6.33

From: Ingo Molnar
Date: Thu Dec 03 2009 - 15:32:08 EST

Linus,

Please pull the latest x86-asm-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git x86-asm-for-linus

The most user visible change here is the (default disabled)
CONFIG_DEBUG_STRICT_USER_COPY_CHECKS security feature, which uses
__builtin_object_size() to validate copy_from_user accesses.

out-of-topic modifications in x86-asm-for-linus:
------------------------------------------------
include/linux/compiler-gcc4.h # 7cff7ce: include/linux/compiler-gcc4.h: Fi
# 63312b6: x86: Add a Kconfig option to turn
# 4a31276: x86: Turn the copy_from_user chec
# 9f0cf4a: x86: Use __builtin_object_size()
include/linux/compiler.h # 63312b6: x86: Add a Kconfig option to turn
# 4a31276: x86: Turn the copy_from_user chec
# 9f0cf4a: x86: Use __builtin_object_size()

Thanks,

Ingo

------------------>
Andrew Morton (1):
include/linux/compiler-gcc4.h: Fix build bug - gcc-4.0.2 doesn't understand __builtin_object_size

Arjan van de Ven (5):
x86: Use __builtin_object_size() to validate the buffer size for copy_from_user()
x86: Use __builtin_memset and __builtin_memcpy for memset/memcpy
x86: Turn the copy_from_user check into an (optional) compile time warning
x86: Add a Kconfig option to turn the copy_from_user warnings into errors
x86: Don't use the strict copy checks when branch profiling is in use

Brian Gerst (4):
x86, 64-bit: Move K8 B step iret fixup to fault entry asm
x86, 64-bit: Fix bstep_iret jump
x86: Optimize loadsegment()
x86, 64-bit: Set data segments to null after switching to 64-bit mode

Frederic Weisbecker (1):
x86: Add missing might_fault() checks to copy_{to,from}_user()

Ingo Molnar (1):
x86: Clean up the loadsegment() macro

Jan Beulich (3):
x86-64: __copy_from_user_inatomic() adjustments
x86/alternatives: Check replacementlen <= instrlen at build time
x86/alternatives: No need for alternatives-asm.h to re-invent stuff already in asm.h

Masami Hiramatsu (1):
x86: Remove unused thread_return label from switch_to()

Peter Zijlstra (1):
x86: Generate cmpxchg build failures


arch/x86/Kconfig.debug | 14 ++
arch/x86/include/asm/alternative-asm.h | 10 +-
arch/x86/include/asm/alternative.h | 1 +
arch/x86/include/asm/cmpxchg_32.h | 218 ++++++++++++------------------
arch/x86/include/asm/cmpxchg_64.h | 234 ++++++++++++-------------------
arch/x86/include/asm/string_32.h | 9 ++
arch/x86/include/asm/system.h | 31 ++--
arch/x86/include/asm/uaccess.h | 1 -
arch/x86/include/asm/uaccess_32.h | 27 ++++-
arch/x86/include/asm/uaccess_64.h | 36 +++++-
arch/x86/kernel/entry_64.S | 11 +-
arch/x86/kernel/head_64.S | 4 +-
arch/x86/kernel/x8664_ksyms_64.c | 5 +-
arch/x86/lib/copy_user_64.S | 14 +--
arch/x86/lib/usercopy_32.c | 10 +-
arch/x86/mm/extable.c | 31 ----
include/linux/compiler-gcc4.h | 8 +
include/linux/compiler.h | 11 ++
18 files changed, 321 insertions(+), 354 deletions(-)

diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index d105f29..fb772b6 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -287,4 +287,18 @@ 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 --git a/arch/x86/include/asm/alternative-asm.h b/arch/x86/include/asm/alternative-asm.h
index e2077d3..b97f786 100644
--- a/arch/x86/include/asm/alternative-asm.h
+++ b/arch/x86/include/asm/alternative-asm.h
@@ -1,17 +1,13 @@
#ifdef __ASSEMBLY__

-#ifdef CONFIG_X86_32
-# define X86_ALIGN .long
-#else
-# define X86_ALIGN .quad
-#endif
+#include <asm/asm.h>

#ifdef CONFIG_SMP
.macro LOCK_PREFIX
1: lock
.section .smp_locks,"a"
- .align 4
- X86_ALIGN 1b
+ _ASM_ALIGN
+ _ASM_PTR 1b
.previous
.endm
#else
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index c240efc..69b74a7 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -84,6 +84,7 @@ static inline void alternatives_smp_switch(int smp) {}
" .byte " __stringify(feature) "\n" /* feature bit */ \
" .byte 662b-661b\n" /* sourcelen */ \
" .byte 664f-663f\n" /* replacementlen */ \
+ " .byte 0xff + (664f-663f) - (662b-661b)\n" /* rlen <= slen */ \
".previous\n" \
".section .altinstr_replacement, \"ax\"\n" \
"663:\n\t" newinstr "\n664:\n" /* replacement */ \
diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h
index 82ceb78..5371174 100644
--- a/arch/x86/include/asm/cmpxchg_32.h
+++ b/arch/x86/include/asm/cmpxchg_32.h
@@ -8,14 +8,50 @@
* you need to test for the feature in boot_cpu_data.
*/

-#define xchg(ptr, v) \
- ((__typeof__(*(ptr)))__xchg((unsigned long)(v), (ptr), sizeof(*(ptr))))
+extern void __xchg_wrong_size(void);
+
+/*
+ * Note: no "lock" prefix even on SMP: xchg always implies lock anyway
+ * Note 2: xchg has side effect, so that attribute volatile is necessary,
+ * but generally the primitive is invalid, *ptr is output argument. --ANK
+ */

struct __xchg_dummy {
unsigned long a[100];
};
#define __xg(x) ((struct __xchg_dummy *)(x))

+#define __xchg(x, ptr, size) \
+({ \
+ __typeof(*(ptr)) __x = (x); \
+ switch (size) { \
+ case 1: \
+ asm volatile("xchgb %b0,%1" \
+ : "=q" (__x) \
+ : "m" (*__xg(ptr)), "0" (__x) \
+ : "memory"); \
+ break; \
+ case 2: \
+ asm volatile("xchgw %w0,%1" \
+ : "=r" (__x) \
+ : "m" (*__xg(ptr)), "0" (__x) \
+ : "memory"); \
+ break; \
+ case 4: \
+ asm volatile("xchgl %0,%1" \
+ : "=r" (__x) \
+ : "m" (*__xg(ptr)), "0" (__x) \
+ : "memory"); \
+ break; \
+ default: \
+ __xchg_wrong_size(); \
+ } \
+ __x; \
+})
+
+#define xchg(ptr, v) \
+ __xchg((v), (ptr), sizeof(*ptr))
+
/*
* The semantics of XCHGCMP8B are a bit strange, this is why
* there is a loop and the loading of %%eax and %%edx has to
@@ -71,57 +107,63 @@ static inline void __set_64bit_var(unsigned long long *ptr,
(unsigned int)((value) >> 32)) \
: __set_64bit(ptr, ll_low((value)), ll_high((value))))

-/*
- * Note: no "lock" prefix even on SMP: xchg always implies lock anyway
- * Note 2: xchg has side effect, so that attribute volatile is necessary,
- * but generally the primitive is invalid, *ptr is output argument. --ANK
- */
-static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
- int size)
-{
- switch (size) {
- case 1:
- asm volatile("xchgb %b0,%1"
- : "=q" (x)
- : "m" (*__xg(ptr)), "0" (x)
- : "memory");
- break;
- case 2:
- asm volatile("xchgw %w0,%1"
- : "=r" (x)
- : "m" (*__xg(ptr)), "0" (x)
- : "memory");
- break;
- case 4:
- asm volatile("xchgl %0,%1"
- : "=r" (x)
- : "m" (*__xg(ptr)), "0" (x)
- : "memory");
- break;
- }
- return x;
-}
+extern void __cmpxchg_wrong_size(void);

/*
* Atomic compare and exchange. Compare OLD with MEM, if identical,
* store NEW in MEM. Return the initial value in MEM. Success is
* indicated by comparing RETURN with OLD.
*/
+#define __raw_cmpxchg(ptr, old, new, size, lock) \
+({ \
+ __typeof__(*(ptr)) __ret; \
+ __typeof__(*(ptr)) __old = (old); \
+ __typeof__(*(ptr)) __new = (new); \
+ switch (size) { \
+ case 1: \
+ asm volatile(lock "cmpxchgb %b1,%2" \
+ : "=a"(__ret) \
+ : "q"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ : "memory"); \
+ break; \
+ case 2: \
+ asm volatile(lock "cmpxchgw %w1,%2" \
+ : "=a"(__ret) \
+ : "r"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ : "memory"); \
+ break; \
+ case 4: \
+ asm volatile(lock "cmpxchgl %1,%2" \
+ : "=a"(__ret) \
+ : "r"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ : "memory"); \
+ break; \
+ default: \
+ __cmpxchg_wrong_size(); \
+ } \
+ __ret; \
+})
+
+#define __cmpxchg(ptr, old, new, size) \
+ __raw_cmpxchg((ptr), (old), (new), (size), LOCK_PREFIX)
+
+#define __sync_cmpxchg(ptr, old, new, size) \
+ __raw_cmpxchg((ptr), (old), (new), (size), "lock; ")
+
+#define __cmpxchg_local(ptr, old, new, size) \
+ __raw_cmpxchg((ptr), (old), (new), (size), "")

#ifdef CONFIG_X86_CMPXCHG
#define __HAVE_ARCH_CMPXCHG 1
-#define cmpxchg(ptr, o, n) \
- ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
- (unsigned long)(n), \
- sizeof(*(ptr))))
-#define sync_cmpxchg(ptr, o, n) \
- ((__typeof__(*(ptr)))__sync_cmpxchg((ptr), (unsigned long)(o), \
- (unsigned long)(n), \
- sizeof(*(ptr))))
-#define cmpxchg_local(ptr, o, n) \
- ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
- (unsigned long)(n), \
- sizeof(*(ptr))))
+
+#define cmpxchg(ptr, old, new) \
+ __cmpxchg((ptr), (old), (new), sizeof(*ptr))
+
+#define sync_cmpxchg(ptr, old, new) \
+ __sync_cmpxchg((ptr), (old), (new), sizeof(*ptr))
+
+#define cmpxchg_local(ptr, old, new) \
+ __cmpxchg_local((ptr), (old), (new), sizeof(*ptr))
#endif

#ifdef CONFIG_X86_CMPXCHG64
@@ -133,94 +175,6 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
(unsigned long long)(n)))
#endif

-static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
- unsigned long new, int size)
-{
- unsigned long prev;
- switch (size) {
- case 1:
- asm volatile(LOCK_PREFIX "cmpxchgb %b1,%2"
- : "=a"(prev)
- : "q"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 2:
- asm volatile(LOCK_PREFIX "cmpxchgw %w1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 4:
- asm volatile(LOCK_PREFIX "cmpxchgl %1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- }
- return old;
-}
-
-/*
- * Always use locked operations when touching memory shared with a
- * hypervisor, since the system may be SMP even if the guest kernel
- * isn't.
- */
-static inline unsigned long __sync_cmpxchg(volatile void *ptr,
- unsigned long old,
- unsigned long new, int size)
-{
- unsigned long prev;
- switch (size) {
- case 1:
- asm volatile("lock; cmpxchgb %b1,%2"
- : "=a"(prev)
- : "q"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 2:
- asm volatile("lock; cmpxchgw %w1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 4:
- asm volatile("lock; cmpxchgl %1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- }
- return old;
-}
-
-static inline unsigned long __cmpxchg_local(volatile void *ptr,
- unsigned long old,
- unsigned long new, int size)
-{
- unsigned long prev;
- switch (size) {
- case 1:
- asm volatile("cmpxchgb %b1,%2"
- : "=a"(prev)
- : "q"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 2:
- asm volatile("cmpxchgw %w1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 4:
- asm volatile("cmpxchgl %1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- }
- return old;
-}
-
static inline unsigned long long __cmpxchg64(volatile void *ptr,
unsigned long long old,
unsigned long long new)
diff --git a/arch/x86/include/asm/cmpxchg_64.h b/arch/x86/include/asm/cmpxchg_64.h
index 52de72e..485ae41 100644
--- a/arch/x86/include/asm/cmpxchg_64.h
+++ b/arch/x86/include/asm/cmpxchg_64.h
@@ -3,9 +3,6 @@

#include <asm/alternative.h> /* Provides LOCK_PREFIX */

-#define xchg(ptr, v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v), \
- (ptr), sizeof(*(ptr))))
-
#define __xg(x) ((volatile long *)(x))

static inline void set_64bit(volatile unsigned long *ptr, unsigned long val)
@@ -15,167 +12,118 @@ static inline void set_64bit(volatile unsigned long *ptr, unsigned long val)

#define _set_64bit set_64bit

+extern void __xchg_wrong_size(void);
+extern void __cmpxchg_wrong_size(void);
+
/*
* Note: no "lock" prefix even on SMP: xchg always implies lock anyway
* Note 2: xchg has side effect, so that attribute volatile is necessary,
* but generally the primitive is invalid, *ptr is output argument. --ANK
*/
-static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
- int size)
-{
- switch (size) {
- case 1:
- asm volatile("xchgb %b0,%1"
- : "=q" (x)
- : "m" (*__xg(ptr)), "0" (x)
- : "memory");
- break;
- case 2:
- asm volatile("xchgw %w0,%1"
- : "=r" (x)
- : "m" (*__xg(ptr)), "0" (x)
- : "memory");
- break;
- case 4:
- asm volatile("xchgl %k0,%1"
- : "=r" (x)
- : "m" (*__xg(ptr)), "0" (x)
- : "memory");
- break;
- case 8:
- asm volatile("xchgq %0,%1"
- : "=r" (x)
- : "m" (*__xg(ptr)), "0" (x)
- : "memory");
- break;
- }
- return x;
-}
+#define __xchg(x, ptr, size) \
+({ \
+ __typeof(*(ptr)) __x = (x); \
+ switch (size) { \
+ case 1: \
+ asm volatile("xchgb %b0,%1" \
+ : "=q" (__x) \
+ : "m" (*__xg(ptr)), "0" (__x) \
+ : "memory"); \
+ break; \
+ case 2: \
+ asm volatile("xchgw %w0,%1" \
+ : "=r" (__x) \
+ : "m" (*__xg(ptr)), "0" (__x) \
+ : "memory"); \
+ break; \
+ case 4: \
+ asm volatile("xchgl %k0,%1" \
+ : "=r" (__x) \
+ : "m" (*__xg(ptr)), "0" (__x) \
+ : "memory"); \
+ break; \
+ case 8: \
+ asm volatile("xchgq %0,%1" \
+ : "=r" (__x) \
+ : "m" (*__xg(ptr)), "0" (__x) \
+ : "memory"); \
+ break; \
+ default: \
+ __xchg_wrong_size(); \
+ } \
+ __x; \
+})
+
+#define xchg(ptr, v) \
+ __xchg((v), (ptr), sizeof(*ptr))
+
+#define __HAVE_ARCH_CMPXCHG 1

/*
* Atomic compare and exchange. Compare OLD with MEM, if identical,
* store NEW in MEM. Return the initial value in MEM. Success is
* indicated by comparing RETURN with OLD.
*/
+#define __raw_cmpxchg(ptr, old, new, size, lock) \
+({ \
+ __typeof__(*(ptr)) __ret; \
+ __typeof__(*(ptr)) __old = (old); \
+ __typeof__(*(ptr)) __new = (new); \
+ switch (size) { \
+ case 1: \
+ asm volatile(lock "cmpxchgb %b1,%2" \
+ : "=a"(__ret) \
+ : "q"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ : "memory"); \
+ break; \
+ case 2: \
+ asm volatile(lock "cmpxchgw %w1,%2" \
+ : "=a"(__ret) \
+ : "r"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ : "memory"); \
+ break; \
+ case 4: \
+ asm volatile(lock "cmpxchgl %k1,%2" \
+ : "=a"(__ret) \
+ : "r"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ : "memory"); \
+ break; \
+ case 8: \
+ asm volatile(lock "cmpxchgq %1,%2" \
+ : "=a"(__ret) \
+ : "r"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ : "memory"); \
+ break; \
+ default: \
+ __cmpxchg_wrong_size(); \
+ } \
+ __ret; \
+})

-#define __HAVE_ARCH_CMPXCHG 1
+#define __cmpxchg(ptr, old, new, size) \
+ __raw_cmpxchg((ptr), (old), (new), (size), LOCK_PREFIX)

-static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
- unsigned long new, int size)
-{
- unsigned long prev;
- switch (size) {
- case 1:
- asm volatile(LOCK_PREFIX "cmpxchgb %b1,%2"
- : "=a"(prev)
- : "q"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 2:
- asm volatile(LOCK_PREFIX "cmpxchgw %w1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 4:
- asm volatile(LOCK_PREFIX "cmpxchgl %k1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 8:
- asm volatile(LOCK_PREFIX "cmpxchgq %1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- }
- return old;
-}
+#define __sync_cmpxchg(ptr, old, new, size) \
+ __raw_cmpxchg((ptr), (old), (new), (size), "lock; ")

-/*
- * Always use locked operations when touching memory shared with a
- * hypervisor, since the system may be SMP even if the guest kernel
- * isn't.
- */
-static inline unsigned long __sync_cmpxchg(volatile void *ptr,
- unsigned long old,
- unsigned long new, int size)
-{
- unsigned long prev;
- switch (size) {
- case 1:
- asm volatile("lock; cmpxchgb %b1,%2"
- : "=a"(prev)
- : "q"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 2:
- asm volatile("lock; cmpxchgw %w1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 4:
- asm volatile("lock; cmpxchgl %1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- }
- return old;
-}
+#define __cmpxchg_local(ptr, old, new, size) \
+ __raw_cmpxchg((ptr), (old), (new), (size), "")

-static inline unsigned long __cmpxchg_local(volatile void *ptr,
- unsigned long old,
- unsigned long new, int size)
-{
- unsigned long prev;
- switch (size) {
- case 1:
- asm volatile("cmpxchgb %b1,%2"
- : "=a"(prev)
- : "q"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 2:
- asm volatile("cmpxchgw %w1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 4:
- asm volatile("cmpxchgl %k1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- case 8:
- asm volatile("cmpxchgq %1,%2"
- : "=a"(prev)
- : "r"(new), "m"(*__xg(ptr)), "0"(old)
- : "memory");
- return prev;
- }
- return old;
-}
+#define cmpxchg(ptr, old, new) \
+ __cmpxchg((ptr), (old), (new), sizeof(*ptr))
+
+#define sync_cmpxchg(ptr, old, new) \
+ __sync_cmpxchg((ptr), (old), (new), sizeof(*ptr))
+
+#define cmpxchg_local(ptr, old, new) \
+ __cmpxchg_local((ptr), (old), (new), sizeof(*ptr))

-#define cmpxchg(ptr, o, n) \
- ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
- (unsigned long)(n), sizeof(*(ptr))))
#define cmpxchg64(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
cmpxchg((ptr), (o), (n)); \
})
-#define cmpxchg_local(ptr, o, n) \
- ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
- (unsigned long)(n), \
- sizeof(*(ptr))))
-#define sync_cmpxchg(ptr, o, n) \
- ((__typeof__(*(ptr)))__sync_cmpxchg((ptr), (unsigned long)(o), \
- (unsigned long)(n), \
- sizeof(*(ptr))))
+
#define cmpxchg64_local(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
diff --git a/arch/x86/include/asm/string_32.h b/arch/x86/include/asm/string_32.h
index ae907e6..3d3e835 100644
--- a/arch/x86/include/asm/string_32.h
+++ b/arch/x86/include/asm/string_32.h
@@ -177,10 +177,15 @@ static inline void *__memcpy3d(void *to, const void *from, size_t len)
*/

#ifndef CONFIG_KMEMCHECK
+
+#if (__GNUC__ >= 4)
+#define memcpy(t, f, n) __builtin_memcpy(t, f, n)
+#else
#define memcpy(t, f, n) \
(__builtin_constant_p((n)) \
? __constant_memcpy((t), (f), (n)) \
: __memcpy((t), (f), (n)))
+#endif
#else
/*
* kmemcheck becomes very happy if we use the REP instructions unconditionally,
@@ -316,11 +321,15 @@ void *__constant_c_and_count_memset(void *s, unsigned long pattern,
: __memset_generic((s), (c), (count)))

#define __HAVE_ARCH_MEMSET
+#if (__GNUC__ >= 4)
+#define memset(s, c, count) __builtin_memset(s, c, count)
+#else
#define memset(s, c, count) \
(__builtin_constant_p(c) \
? __constant_c_x_memset((s), (0x01010101UL * (unsigned char)(c)), \
(count)) \
: __memset((s), (c), (count)))
+#endif

/*
* find the first occurrence of byte 'c', or 1 past the area if none
diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h
index f08f973..022a843 100644
--- a/arch/x86/include/asm/system.h
+++ b/arch/x86/include/asm/system.h
@@ -128,8 +128,6 @@ do { \
"movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \
"movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */ \
"call __switch_to\n\t" \
- ".globl thread_return\n" \
- "thread_return:\n\t" \
"movq "__percpu_arg([current_task])",%%rsi\n\t" \
__switch_canary \
"movq %P[thread_info](%%rsi),%%r8\n\t" \
@@ -157,19 +155,22 @@ extern void native_load_gs_index(unsigned);
* Load a segment. Fall back on loading the zero
* segment if something goes wrong..
*/
-#define loadsegment(seg, value) \
- asm volatile("\n" \
- "1:\t" \
- "movl %k0,%%" #seg "\n" \
- "2:\n" \
- ".section .fixup,\"ax\"\n" \
- "3:\t" \
- "movl %k1, %%" #seg "\n\t" \
- "jmp 2b\n" \
- ".previous\n" \
- _ASM_EXTABLE(1b,3b) \
- : :"r" (value), "r" (0) : "memory")
-
+#define loadsegment(seg, value) \
+do { \
+ unsigned short __val = (value); \
+ \
+ asm volatile(" \n" \
+ "1: movl %k0,%%" #seg " \n" \
+ \
+ ".section .fixup,\"ax\" \n" \
+ "2: xorl %k0,%k0 \n" \
+ " jmp 1b \n" \
+ ".previous \n" \
+ \
+ _ASM_EXTABLE(1b, 2b) \
+ \
+ : "+r" (__val) : : "memory"); \
+} while (0)

/*
* Save a segment register away
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index d2c6c93..abd3e0e 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -570,7 +570,6 @@ extern struct movsl_mask {
#ifdef CONFIG_X86_32
# include "uaccess_32.h"
#else
-# define ARCH_HAS_SEARCH_EXTABLE
# include "uaccess_64.h"
#endif

diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h
index 632fb44..0c9825e 100644
--- a/arch/x86/include/asm/uaccess_32.h
+++ b/arch/x86/include/asm/uaccess_32.h
@@ -187,9 +187,34 @@ __copy_from_user_inatomic_nocache(void *to, const void __user *from,

unsigned long __must_check copy_to_user(void __user *to,
const void *from, unsigned long n);
-unsigned long __must_check copy_from_user(void *to,
+unsigned long __must_check _copy_from_user(void *to,
const void __user *from,
unsigned long n);
+
+
+extern void copy_from_user_overflow(void)
+#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
+ __compiletime_error("copy_from_user() buffer size is not provably correct")
+#else
+ __compiletime_warning("copy_from_user() buffer size is not provably correct")
+#endif
+;
+
+static inline unsigned long __must_check copy_from_user(void *to,
+ const void __user *from,
+ unsigned long n)
+{
+ int sz = __compiletime_object_size(to);
+ int ret = -EFAULT;
+
+ if (likely(sz == -1 || sz >= n))
+ ret = _copy_from_user(to, from, n);
+ else
+ copy_from_user_overflow();
+
+ return ret;
+}
+
long __must_check strncpy_from_user(char *dst, const char __user *src,
long count);
long __must_check __strncpy_from_user(char *dst,
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index db24b21..46324c6 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -19,12 +19,37 @@ __must_check unsigned long
copy_user_generic(void *to, const void *from, unsigned len);

__must_check unsigned long
-copy_to_user(void __user *to, const void *from, unsigned len);
+_copy_to_user(void __user *to, const void *from, unsigned len);
__must_check unsigned long
-copy_from_user(void *to, const void __user *from, unsigned len);
+_copy_from_user(void *to, const void __user *from, unsigned len);
__must_check unsigned long
copy_in_user(void __user *to, const void __user *from, unsigned len);

+static inline unsigned long __must_check copy_from_user(void *to,
+ const void __user *from,
+ unsigned long n)
+{
+ int sz = __compiletime_object_size(to);
+ int ret = -EFAULT;
+
+ might_fault();
+ if (likely(sz == -1 || sz >= n))
+ ret = _copy_from_user(to, from, n);
+#ifdef CONFIG_DEBUG_VM
+ else
+ WARN(1, "Buffer overflow detected!\n");
+#endif
+ return ret;
+}
+
+static __always_inline __must_check
+int copy_to_user(void __user *dst, const void *src, unsigned size)
+{
+ might_fault();
+
+ return _copy_to_user(dst, src, size);
+}
+
static __always_inline __must_check
int __copy_from_user(void *dst, const void __user *src, unsigned size)
{
@@ -176,8 +201,11 @@ __must_check long strlen_user(const char __user *str);
__must_check unsigned long clear_user(void __user *mem, unsigned long len);
__must_check unsigned long __clear_user(void __user *mem, unsigned long len);

-__must_check long __copy_from_user_inatomic(void *dst, const void __user *src,
- unsigned size);
+static __must_check __always_inline int
+__copy_from_user_inatomic(void *dst, const void __user *src, unsigned size)
+{
+ return copy_user_generic(dst, (__force const void *)src, size);
+}

static __must_check __always_inline int
__copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index b5c061f..1579a6c 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1491,12 +1491,17 @@ error_kernelspace:
leaq irq_return(%rip),%rcx
cmpq %rcx,RIP+8(%rsp)
je error_swapgs
- movl %ecx,%ecx /* zero extend */
- cmpq %rcx,RIP+8(%rsp)
- je error_swapgs
+ movl %ecx,%eax /* zero extend */
+ cmpq %rax,RIP+8(%rsp)
+ je bstep_iret
cmpq $gs_change,RIP+8(%rsp)
je error_swapgs
jmp error_sti
+
+bstep_iret:
+ /* Fix truncated RIP */
+ movq %rcx,RIP+8(%rsp)
+ jmp error_swapgs
END(error_entry)


diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 2640660..17ba9ec 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -212,8 +212,8 @@ ENTRY(secondary_startup_64)
*/
lgdt early_gdt_descr(%rip)

- /* set up data segments. actually 0 would do too */
- movl $__KERNEL_DS,%eax
+ /* set up data segments */
+ xorl %eax,%eax
movl %eax,%ds
movl %eax,%ss
movl %eax,%es
diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c
index 3909e3b..a102976 100644
--- a/arch/x86/kernel/x8664_ksyms_64.c
+++ b/arch/x86/kernel/x8664_ksyms_64.c
@@ -30,9 +30,8 @@ EXPORT_SYMBOL(__put_user_8);

EXPORT_SYMBOL(copy_user_generic);
EXPORT_SYMBOL(__copy_user_nocache);
-EXPORT_SYMBOL(copy_from_user);
-EXPORT_SYMBOL(copy_to_user);
-EXPORT_SYMBOL(__copy_from_user_inatomic);
+EXPORT_SYMBOL(_copy_from_user);
+EXPORT_SYMBOL(_copy_to_user);

EXPORT_SYMBOL(copy_page);
EXPORT_SYMBOL(clear_page);
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index 6ba0f7b..cf889d4 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -65,7 +65,7 @@
.endm

/* Standard copy_to_user with segment limit checking */
-ENTRY(copy_to_user)
+ENTRY(_copy_to_user)
CFI_STARTPROC
GET_THREAD_INFO(%rax)
movq %rdi,%rcx
@@ -75,10 +75,10 @@ ENTRY(copy_to_user)
jae bad_to_user
ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string
CFI_ENDPROC
-ENDPROC(copy_to_user)
+ENDPROC(_copy_to_user)

/* Standard copy_from_user with segment limit checking */
-ENTRY(copy_from_user)
+ENTRY(_copy_from_user)
CFI_STARTPROC
GET_THREAD_INFO(%rax)
movq %rsi,%rcx
@@ -88,7 +88,7 @@ ENTRY(copy_from_user)
jae bad_from_user
ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string
CFI_ENDPROC
-ENDPROC(copy_from_user)
+ENDPROC(_copy_from_user)

ENTRY(copy_user_generic)
CFI_STARTPROC
@@ -96,12 +96,6 @@ ENTRY(copy_user_generic)
CFI_ENDPROC
ENDPROC(copy_user_generic)

-ENTRY(__copy_from_user_inatomic)
- CFI_STARTPROC
- ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string
- CFI_ENDPROC
-ENDPROC(__copy_from_user_inatomic)
-
.section .fixup,"ax"
/* must zero dest */
ENTRY(bad_from_user)
diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
index 1f118d4..e218d5d 100644
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -874,7 +874,7 @@ EXPORT_SYMBOL(copy_to_user);
* data to the requested size using zero bytes.
*/
unsigned long
-copy_from_user(void *to, const void __user *from, unsigned long n)
+_copy_from_user(void *to, const void __user *from, unsigned long n)
{
if (access_ok(VERIFY_READ, from, n))
n = __copy_from_user(to, from, n);
@@ -882,4 +882,10 @@ copy_from_user(void *to, const void __user *from, unsigned long n)
memset(to, 0, n);
return n;
}
-EXPORT_SYMBOL(copy_from_user);
+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/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 61b41ca..d0474ad 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -35,34 +35,3 @@ int fixup_exception(struct pt_regs *regs)

return 0;
}
-
-#ifdef CONFIG_X86_64
-/*
- * Need to defined our own search_extable on X86_64 to work around
- * a B stepping K8 bug.
- */
-const struct exception_table_entry *
-search_extable(const struct exception_table_entry *first,
- const struct exception_table_entry *last,
- unsigned long value)
-{
- /* B stepping K8 bug */
- if ((value >> 32) == 0)
- value |= 0xffffffffUL << 32;
-
- while (first <= last) {
- const struct exception_table_entry *mid;
- long diff;
-
- mid = (last - first) / 2 + first;
- diff = mid->insn - value;
- if (diff == 0)
- return mid;
- else if (diff < 0)
- first = mid+1;
- else
- last = mid-1;
- }
- return NULL;
-}
-#endif
diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h
index 450fa59..e6ef279 100644
--- a/include/linux/compiler-gcc4.h
+++ b/include/linux/compiler-gcc4.h
@@ -37,3 +37,11 @@
#define __cold __attribute__((__cold__))

#endif
+
+#if __GNUC_MINOR__ > 0
+#define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
+#endif
+#if __GNUC_MINOR__ >= 4
+#define __compiletime_warning(message) __attribute__((warning(message)))
+#define __compiletime_error(message) __attribute__((error(message)))
+#endif
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 04fb513..88fd4b6 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -266,6 +266,17 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
#endif

+/* Compile time object size, -1 for unknown */
+#ifndef __compiletime_object_size
+# define __compiletime_object_size(obj) -1
+#endif
+#ifndef __compiletime_warning
+# define __compiletime_warning(message)
+#endif
+#ifndef __compiletime_error
+# define __compiletime_error(message)
+#endif
+
/*
* Prevent the compiler from merging or refetching accesses. The compiler
* is also forbidden from reordering successive instances of ACCESS_ONCE(),
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/