diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-06 02:32:03 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-06 02:32:03 +0300 |
commit | ef26b1691d11e17af205a4ff9c91458d931d11db (patch) | |
tree | 5db199f404ca18f6c9e8617b684e9165ca365e30 /arch | |
parent | a77d2e081bbbccb38f42da45500dd089756efdfb (diff) | |
parent | 7cff7ce94a7df2ccf5ac76b48ee0995fee2060df (diff) | |
download | linux-ef26b1691d11e17af205a4ff9c91458d931d11db.tar.xz |
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
include/linux/compiler-gcc4.h: Fix build bug - gcc-4.0.2 doesn't understand __builtin_object_size
x86/alternatives: No need for alternatives-asm.h to re-invent stuff already in asm.h
x86/alternatives: Check replacementlen <= instrlen at build time
x86, 64-bit: Set data segments to null after switching to 64-bit mode
x86: Clean up the loadsegment() macro
x86: Optimize loadsegment()
x86: Add missing might_fault() checks to copy_{to,from}_user()
x86-64: __copy_from_user_inatomic() adjustments
x86: Remove unused thread_return label from switch_to()
x86, 64-bit: Fix bstep_iret jump
x86: Don't use the strict copy checks when branch profiling is in use
x86, 64-bit: Move K8 B step iret fixup to fault entry asm
x86: Generate cmpxchg build failures
x86: Add a Kconfig option to turn the copy_from_user warnings into errors
x86: Turn the copy_from_user check into an (optional) compile time warning
x86: Use __builtin_memset and __builtin_memcpy for memset/memcpy
x86: Use __builtin_object_size() to validate the buffer size for copy_from_user()
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/Kconfig.debug | 14 | ||||
-rw-r--r-- | arch/x86/include/asm/alternative-asm.h | 10 | ||||
-rw-r--r-- | arch/x86/include/asm/alternative.h | 1 | ||||
-rw-r--r-- | arch/x86/include/asm/cmpxchg_32.h | 218 | ||||
-rw-r--r-- | arch/x86/include/asm/cmpxchg_64.h | 234 | ||||
-rw-r--r-- | arch/x86/include/asm/string_32.h | 9 | ||||
-rw-r--r-- | arch/x86/include/asm/system.h | 31 | ||||
-rw-r--r-- | arch/x86/include/asm/uaccess.h | 1 | ||||
-rw-r--r-- | arch/x86/include/asm/uaccess_32.h | 27 | ||||
-rw-r--r-- | arch/x86/include/asm/uaccess_64.h | 36 | ||||
-rw-r--r-- | arch/x86/kernel/entry_64.S | 11 | ||||
-rw-r--r-- | arch/x86/kernel/head_64.S | 4 | ||||
-rw-r--r-- | arch/x86/kernel/x8664_ksyms_64.c | 5 | ||||
-rw-r--r-- | arch/x86/lib/copy_user_64.S | 14 | ||||
-rw-r--r-- | arch/x86/lib/usercopy_32.c | 10 | ||||
-rw-r--r-- | arch/x86/mm/extable.c | 31 |
16 files changed, 302 insertions, 354 deletions
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 7d0b681a132b..731318e5ac1d 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -296,4 +296,18 @@ 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 e2077d343c33..b97f786a48d5 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 c240efc74e00..69b74a7b877f 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 ee1931be6593..ffb9bb6b6c37 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 52de72e0de8c..485ae415faec 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 ae907e617181..3d3e8353ee5c 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 f08f97374892..022a84386de8 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 d2c6c930b491..abd3e0ea762a 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 632fb44b4cb5..0c9825e97f36 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 db24b215fc50..46324c6a4f6e 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 722df1b1152d..4deb8fc849dd 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1499,12 +1499,17 @@ 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 780cd928fcd5..22db86a37643 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 3909e3ba5ce3..a1029769b6f2 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 6ba0f7bb85ea..cf889d4e076a 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 1f118d462acc..e218d5df85ff 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 61b41ca3b5a2..d0474ad2a6e5 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 |