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authorClark Williams <williams@redhat.com>2012-04-15 23:24:46 -0500
committerClark Williams <williams@redhat.com>2012-04-15 23:24:46 -0500
commit8e9c931b8e4150f3c5aaab7e4639cd507c30477c (patch)
tree4c77bef833db938a950c60095f628acc1ebff50a /arch/x86
parent3524a83e5459ae4ba42f9bf098bb736b99b88695 (diff)
parente816b57a337ea3b755de72bec38c10c864f23015 (diff)
Merge commit 'v3.4-rc3' into rt-3.4-rc3-rt4v3.4-rc3-rt4
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/Makefile.um3
-rw-r--r--arch/x86/include/asm/cmpxchg.h4
-rw-r--r--arch/x86/include/asm/uaccess.h2
-rw-r--r--arch/x86/include/asm/uaccess_32.h5
-rw-r--r--arch/x86/include/asm/uaccess_64.h4
-rw-r--r--arch/x86/kernel/vsyscall_64.c6
-rw-r--r--arch/x86/lib/usercopy.c103
-rw-r--r--arch/x86/lib/usercopy_32.c87
-rw-r--r--arch/x86/lib/usercopy_64.c49
-rw-r--r--arch/x86/um/asm/barrier.h75
-rw-r--r--arch/x86/um/asm/system.h135
11 files changed, 188 insertions, 285 deletions
diff --git a/arch/x86/Makefile.um b/arch/x86/Makefile.um
index 4be406abeefd..36b62bc52638 100644
--- a/arch/x86/Makefile.um
+++ b/arch/x86/Makefile.um
@@ -14,6 +14,9 @@ LINK-y += $(call cc-option,-m32)
export LDFLAGS
+LDS_EXTRA := -Ui386
+export LDS_EXTRA
+
# First of all, tune CFLAGS for the specific CPU. This actually sets cflags-y.
include $(srctree)/arch/x86/Makefile_32.cpu
diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h
index b3b733262909..99480e55973d 100644
--- a/arch/x86/include/asm/cmpxchg.h
+++ b/arch/x86/include/asm/cmpxchg.h
@@ -43,7 +43,7 @@ extern void __add_wrong_size(void)
switch (sizeof(*(ptr))) { \
case __X86_CASE_B: \
asm volatile (lock #op "b %b0, %1\n" \
- : "+r" (__ret), "+m" (*(ptr)) \
+ : "+q" (__ret), "+m" (*(ptr)) \
: : "memory", "cc"); \
break; \
case __X86_CASE_W: \
@@ -173,7 +173,7 @@ extern void __add_wrong_size(void)
switch (sizeof(*(ptr))) { \
case __X86_CASE_B: \
asm volatile (lock "addb %b1, %0\n" \
- : "+m" (*(ptr)) : "ri" (inc) \
+ : "+m" (*(ptr)) : "qi" (inc) \
: "memory", "cc"); \
break; \
case __X86_CASE_W: \
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 8be5f54d9360..e0544597cfe7 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -557,6 +557,8 @@ struct __large_struct { unsigned long buf[100]; };
extern unsigned long
copy_from_user_nmi(void *to, const void __user *from, unsigned long n);
+extern __must_check long
+strncpy_from_user(char *dst, const char __user *src, long count);
/*
* movsl can be slow when source and dest are not both 8-byte aligned
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h
index 566e803cc602..8084bc73b18c 100644
--- a/arch/x86/include/asm/uaccess_32.h
+++ b/arch/x86/include/asm/uaccess_32.h
@@ -213,11 +213,6 @@ static inline unsigned long __must_check copy_from_user(void *to,
return n;
}
-long __must_check strncpy_from_user(char *dst, const char __user *src,
- long count);
-long __must_check __strncpy_from_user(char *dst,
- const char __user *src, long count);
-
/**
* strlen_user: - Get the size of a string in user space.
* @str: The string to measure.
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index 1c66d30971ad..fcd4b6f3ef02 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -208,10 +208,6 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
}
}
-__must_check long
-strncpy_from_user(char *dst, const char __user *src, long count);
-__must_check long
-__strncpy_from_user(char *dst, const char __user *src, long count);
__must_check long strnlen_user(const char __user *str, long n);
__must_check long __strnlen_user(const char __user *str, long n);
__must_check long strlen_user(const char __user *str);
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index f386dc49f988..7515cf0e1805 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -216,9 +216,9 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
current_thread_info()->sig_on_uaccess_error = 1;
/*
- * 0 is a valid user pointer (in the access_ok sense) on 32-bit and
+ * NULL is a valid user pointer (in the access_ok sense) on 32-bit and
* 64-bit, so we don't need to special-case it here. For all the
- * vsyscalls, 0 means "don't write anything" not "write it at
+ * vsyscalls, NULL means "don't write anything" not "write it at
* address 0".
*/
ret = -EFAULT;
@@ -247,7 +247,7 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
ret = sys_getcpu((unsigned __user *)regs->di,
(unsigned __user *)regs->si,
- 0);
+ NULL);
break;
}
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c
index 97be9cb54483..d6ae30bbd7bb 100644
--- a/arch/x86/lib/usercopy.c
+++ b/arch/x86/lib/usercopy.c
@@ -7,6 +7,8 @@
#include <linux/highmem.h>
#include <linux/module.h>
+#include <asm/word-at-a-time.h>
+
/*
* best effort, GUP based copy_from_user() that is NMI-safe
*/
@@ -41,3 +43,104 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
return len;
}
EXPORT_SYMBOL_GPL(copy_from_user_nmi);
+
+static inline unsigned long count_bytes(unsigned long mask)
+{
+ mask = (mask - 1) & ~mask;
+ mask >>= 7;
+ return count_masked_bytes(mask);
+}
+
+/*
+ * Do a strncpy, return length of string without final '\0'.
+ * 'count' is the user-supplied count (return 'count' if we
+ * hit it), 'max' is the address space maximum (and we return
+ * -EFAULT if we hit it).
+ */
+static inline long do_strncpy_from_user(char *dst, const char __user *src, long count, unsigned long max)
+{
+ long res = 0;
+
+ /*
+ * Truncate 'max' to the user-specified limit, so that
+ * we only have one limit we need to check in the loop
+ */
+ if (max > count)
+ max = count;
+
+ while (max >= sizeof(unsigned long)) {
+ unsigned long c;
+
+ /* Fall back to byte-at-a-time if we get a page fault */
+ if (unlikely(__get_user(c,(unsigned long __user *)(src+res))))
+ break;
+ /* This can write a few bytes past the NUL character, but that's ok */
+ *(unsigned long *)(dst+res) = c;
+ c = has_zero(c);
+ if (c)
+ return res + count_bytes(c);
+ res += sizeof(unsigned long);
+ max -= sizeof(unsigned long);
+ }
+
+ while (max) {
+ char c;
+
+ if (unlikely(__get_user(c,src+res)))
+ return -EFAULT;
+ dst[res] = c;
+ if (!c)
+ return res;
+ res++;
+ max--;
+ }
+
+ /*
+ * Uhhuh. We hit 'max'. But was that the user-specified maximum
+ * too? If so, that's ok - we got as much as the user asked for.
+ */
+ if (res >= count)
+ return res;
+
+ /*
+ * Nope: we hit the address space limit, and we still had more
+ * characters the caller would have wanted. That's an EFAULT.
+ */
+ return -EFAULT;
+}
+
+/**
+ * strncpy_from_user: - Copy a NUL terminated string from userspace.
+ * @dst: Destination address, in kernel space. This buffer must be at
+ * least @count bytes long.
+ * @src: Source address, in user space.
+ * @count: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Copies a NUL-terminated string from userspace to kernel space.
+ *
+ * On success, returns the length of the string (not including the trailing
+ * NUL).
+ *
+ * If access to userspace fails, returns -EFAULT (some data may have been
+ * copied).
+ *
+ * If @count is smaller than the length of the string, copies @count bytes
+ * and returns @count.
+ */
+long
+strncpy_from_user(char *dst, const char __user *src, long count)
+{
+ unsigned long max_addr, src_addr;
+
+ if (unlikely(count <= 0))
+ return 0;
+
+ max_addr = current_thread_info()->addr_limit.seg;
+ src_addr = (unsigned long)src;
+ if (likely(src_addr < max_addr)) {
+ unsigned long max = max_addr - src_addr;
+ return do_strncpy_from_user(dst, src, count, max);
+ }
+ return -EFAULT;
+}
+EXPORT_SYMBOL(strncpy_from_user);
diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
index d9b094ca7aaa..ef2a6a5d78e3 100644
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -33,93 +33,6 @@ static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned lon
__movsl_is_ok((unsigned long)(a1), (unsigned long)(a2), (n))
/*
- * Copy a null terminated string from userspace.
- */
-
-#define __do_strncpy_from_user(dst, src, count, res) \
-do { \
- int __d0, __d1, __d2; \
- might_fault(); \
- __asm__ __volatile__( \
- " testl %1,%1\n" \
- " jz 2f\n" \
- "0: lodsb\n" \
- " stosb\n" \
- " testb %%al,%%al\n" \
- " jz 1f\n" \
- " decl %1\n" \
- " jnz 0b\n" \
- "1: subl %1,%0\n" \
- "2:\n" \
- ".section .fixup,\"ax\"\n" \
- "3: movl %5,%0\n" \
- " jmp 2b\n" \
- ".previous\n" \
- _ASM_EXTABLE(0b,3b) \
- : "=&d"(res), "=&c"(count), "=&a" (__d0), "=&S" (__d1), \
- "=&D" (__d2) \
- : "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \
- : "memory"); \
-} while (0)
-
-/**
- * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
- * @dst: Destination address, in kernel space. This buffer must be at
- * least @count bytes long.
- * @src: Source address, in user space.
- * @count: Maximum number of bytes to copy, including the trailing NUL.
- *
- * Copies a NUL-terminated string from userspace to kernel space.
- * Caller must check the specified block with access_ok() before calling
- * this function.
- *
- * On success, returns the length of the string (not including the trailing
- * NUL).
- *
- * If access to userspace fails, returns -EFAULT (some data may have been
- * copied).
- *
- * If @count is smaller than the length of the string, copies @count bytes
- * and returns @count.
- */
-long
-__strncpy_from_user(char *dst, const char __user *src, long count)
-{
- long res;
- __do_strncpy_from_user(dst, src, count, res);
- return res;
-}
-EXPORT_SYMBOL(__strncpy_from_user);
-
-/**
- * strncpy_from_user: - Copy a NUL terminated string from userspace.
- * @dst: Destination address, in kernel space. This buffer must be at
- * least @count bytes long.
- * @src: Source address, in user space.
- * @count: Maximum number of bytes to copy, including the trailing NUL.
- *
- * Copies a NUL-terminated string from userspace to kernel space.
- *
- * On success, returns the length of the string (not including the trailing
- * NUL).
- *
- * If access to userspace fails, returns -EFAULT (some data may have been
- * copied).
- *
- * If @count is smaller than the length of the string, copies @count bytes
- * and returns @count.
- */
-long
-strncpy_from_user(char *dst, const char __user *src, long count)
-{
- long res = -EFAULT;
- if (access_ok(VERIFY_READ, src, 1))
- __do_strncpy_from_user(dst, src, count, res);
- return res;
-}
-EXPORT_SYMBOL(strncpy_from_user);
-
-/*
* Zero Userspace
*/
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index b7c2849ffb66..0d0326f388c0 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -9,55 +9,6 @@
#include <asm/uaccess.h>
/*
- * Copy a null terminated string from userspace.
- */
-
-#define __do_strncpy_from_user(dst,src,count,res) \
-do { \
- long __d0, __d1, __d2; \
- might_fault(); \
- __asm__ __volatile__( \
- " testq %1,%1\n" \
- " jz 2f\n" \
- "0: lodsb\n" \
- " stosb\n" \
- " testb %%al,%%al\n" \
- " jz 1f\n" \
- " decq %1\n" \
- " jnz 0b\n" \
- "1: subq %1,%0\n" \
- "2:\n" \
- ".section .fixup,\"ax\"\n" \
- "3: movq %5,%0\n" \
- " jmp 2b\n" \
- ".previous\n" \
- _ASM_EXTABLE(0b,3b) \
- : "=&r"(res), "=&c"(count), "=&a" (__d0), "=&S" (__d1), \
- "=&D" (__d2) \
- : "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \
- : "memory"); \
-} while (0)
-
-long
-__strncpy_from_user(char *dst, const char __user *src, long count)
-{
- long res;
- __do_strncpy_from_user(dst, src, count, res);
- return res;
-}
-EXPORT_SYMBOL(__strncpy_from_user);
-
-long
-strncpy_from_user(char *dst, const char __user *src, long count)
-{
- long res = -EFAULT;
- if (access_ok(VERIFY_READ, src, 1))
- return __strncpy_from_user(dst, src, count);
- return res;
-}
-EXPORT_SYMBOL(strncpy_from_user);
-
-/*
* Zero Userspace
*/
diff --git a/arch/x86/um/asm/barrier.h b/arch/x86/um/asm/barrier.h
new file mode 100644
index 000000000000..7d01b8c56c00
--- /dev/null
+++ b/arch/x86/um/asm/barrier.h
@@ -0,0 +1,75 @@
+#ifndef _ASM_UM_BARRIER_H_
+#define _ASM_UM_BARRIER_H_
+
+#include <asm/asm.h>
+#include <asm/segment.h>
+#include <asm/cpufeature.h>
+#include <asm/cmpxchg.h>
+#include <asm/nops.h>
+
+#include <linux/kernel.h>
+#include <linux/irqflags.h>
+
+/*
+ * Force strict CPU ordering.
+ * And yes, this is required on UP too when we're talking
+ * to devices.
+ */
+#ifdef CONFIG_X86_32
+
+#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
+#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
+#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
+
+#else /* CONFIG_X86_32 */
+
+#define mb() asm volatile("mfence" : : : "memory")
+#define rmb() asm volatile("lfence" : : : "memory")
+#define wmb() asm volatile("sfence" : : : "memory")
+
+#endif /* CONFIG_X86_32 */
+
+#define read_barrier_depends() do { } while (0)
+
+#ifdef CONFIG_SMP
+
+#define smp_mb() mb()
+#ifdef CONFIG_X86_PPRO_FENCE
+#define smp_rmb() rmb()
+#else /* CONFIG_X86_PPRO_FENCE */
+#define smp_rmb() barrier()
+#endif /* CONFIG_X86_PPRO_FENCE */
+
+#ifdef CONFIG_X86_OOSTORE
+#define smp_wmb() wmb()
+#else /* CONFIG_X86_OOSTORE */
+#define smp_wmb() barrier()
+#endif /* CONFIG_X86_OOSTORE */
+
+#define smp_read_barrier_depends() read_barrier_depends()
+#define set_mb(var, value) do { (void)xchg(&var, value); } while (0)
+
+#else /* CONFIG_SMP */
+
+#define smp_mb() barrier()
+#define smp_rmb() barrier()
+#define smp_wmb() barrier()
+#define smp_read_barrier_depends() do { } while (0)
+#define set_mb(var, value) do { var = value; barrier(); } while (0)
+
+#endif /* CONFIG_SMP */
+
+/*
+ * Stop RDTSC speculation. This is needed when you need to use RDTSC
+ * (or get_cycles or vread that possibly accesses the TSC) in a defined
+ * code region.
+ *
+ * (Could use an alternative three way for this if there was one.)
+ */
+static inline void rdtsc_barrier(void)
+{
+ alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC);
+ alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC);
+}
+
+#endif
diff --git a/arch/x86/um/asm/system.h b/arch/x86/um/asm/system.h
deleted file mode 100644
index a459fd9b7598..000000000000
--- a/arch/x86/um/asm/system.h
+++ /dev/null
@@ -1,135 +0,0 @@
-#ifndef _ASM_X86_SYSTEM_H_
-#define _ASM_X86_SYSTEM_H_
-
-#include <asm/asm.h>
-#include <asm/segment.h>
-#include <asm/cpufeature.h>
-#include <asm/cmpxchg.h>
-#include <asm/nops.h>
-
-#include <linux/kernel.h>
-#include <linux/irqflags.h>
-
-/* entries in ARCH_DLINFO: */
-#ifdef CONFIG_IA32_EMULATION
-# define AT_VECTOR_SIZE_ARCH 2
-#else
-# define AT_VECTOR_SIZE_ARCH 1
-#endif
-
-extern unsigned long arch_align_stack(unsigned long sp);
-
-void default_idle(void);
-
-/*
- * Force strict CPU ordering.
- * And yes, this is required on UP too when we're talking
- * to devices.
- */
-#ifdef CONFIG_X86_32
-/*
- * Some non-Intel clones support out of order store. wmb() ceases to be a
- * nop for these.
- */
-#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
-#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
-#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
-#else
-#define mb() asm volatile("mfence":::"memory")
-#define rmb() asm volatile("lfence":::"memory")
-#define wmb() asm volatile("sfence" ::: "memory")
-#endif
-
-/**
- * read_barrier_depends - Flush all pending reads that subsequents reads
- * depend on.
- *
- * No data-dependent reads from memory-like regions are ever reordered
- * over this barrier. All reads preceding this primitive are guaranteed
- * to access memory (but not necessarily other CPUs' caches) before any
- * reads following this primitive that depend on the data return by
- * any of the preceding reads. This primitive is much lighter weight than
- * rmb() on most CPUs, and is never heavier weight than is
- * rmb().
- *
- * These ordering constraints are respected by both the local CPU
- * and the compiler.
- *
- * Ordering is not guaranteed by anything other than these primitives,
- * not even by data dependencies. See the documentation for
- * memory_barrier() for examples and URLs to more information.
- *
- * For example, the following code would force ordering (the initial
- * value of "a" is zero, "b" is one, and "p" is "&a"):
- *
- * <programlisting>
- * CPU 0 CPU 1
- *
- * b = 2;
- * memory_barrier();
- * p = &b; q = p;
- * read_barrier_depends();
- * d = *q;
- * </programlisting>
- *
- * because the read of "*q" depends on the read of "p" and these
- * two reads are separated by a read_barrier_depends(). However,
- * the following code, with the same initial values for "a" and "b":
- *
- * <programlisting>
- * CPU 0 CPU 1
- *
- * a = 2;
- * memory_barrier();
- * b = 3; y = b;
- * read_barrier_depends();
- * x = a;
- * </programlisting>
- *
- * does not enforce ordering, since there is no data dependency between
- * the read of "a" and the read of "b". Therefore, on some CPUs, such
- * as Alpha, "y" could be set to 3 and "x" to 0. Use rmb()
- * in cases like this where there are no data dependencies.
- **/
-
-#define read_barrier_depends() do { } while (0)
-
-#ifdef CONFIG_SMP
-#define smp_mb() mb()
-#ifdef CONFIG_X86_PPRO_FENCE
-# define smp_rmb() rmb()
-#else
-# define smp_rmb() barrier()
-#endif
-#ifdef CONFIG_X86_OOSTORE
-# define smp_wmb() wmb()
-#else
-# define smp_wmb() barrier()
-#endif
-#define smp_read_barrier_depends() read_barrier_depends()
-#define set_mb(var, value) do { (void)xchg(&var, value); } while (0)
-#else
-#define smp_mb() barrier()
-#define smp_rmb() barrier()
-#define smp_wmb() barrier()
-#define smp_read_barrier_depends() do { } while (0)
-#define set_mb(var, value) do { var = value; barrier(); } while (0)
-#endif
-
-/*
- * Stop RDTSC speculation. This is needed when you need to use RDTSC
- * (or get_cycles or vread that possibly accesses the TSC) in a defined
- * code region.
- *
- * (Could use an alternative three way for this if there was one.)
- */
-static inline void rdtsc_barrier(void)
-{
- alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC);
- alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC);
-}
-
-extern void *_switch_to(void *prev, void *next, void *last);
-#define switch_to(prev, next, last) prev = _switch_to(prev, next, last)
-
-#endif