Merge branch 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull uaccess unification updates from Al Viro:
 "This is the uaccess unification pile. It's _not_ the end of uaccess
  work, but the next batch of that will go into the next cycle. This one
  mostly takes copy_from_user() and friends out of arch/* and gets the
  zero-padding behaviour in sync for all architectures.

  Dealing with the nocache/writethrough mess is for the next cycle;
  fortunately, that's x86-only. Same for cleanups in iov_iter.c (I am
  sold on access_ok() in there, BTW; just not in this pile), same for
  reducing __copy_... callsites, strn*... stuff, etc. - there will be a
  pile about as large as this one in the next merge window.

  This one sat in -next for weeks. -3KLoC"

* 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (96 commits)
  HAVE_ARCH_HARDENED_USERCOPY is unconditional now
  CONFIG_ARCH_HAS_RAW_COPY_USER is unconditional now
  m32r: switch to RAW_COPY_USER
  hexagon: switch to RAW_COPY_USER
  microblaze: switch to RAW_COPY_USER
  get rid of padding, switch to RAW_COPY_USER
  ia64: get rid of copy_in_user()
  ia64: sanitize __access_ok()
  ia64: get rid of 'segment' argument of __do_{get,put}_user()
  ia64: get rid of 'segment' argument of __{get,put}_user_check()
  ia64: add extable.h
  powerpc: get rid of zeroing, switch to RAW_COPY_USER
  esas2r: don't open-code memdup_user()
  alpha: fix stack smashing in old_adjtimex(2)
  don't open-code kernel_setsockopt()
  mips: switch to RAW_COPY_USER
  mips: get rid of tail-zeroing in primitives
  mips: make copy_from_user() zero tail explicitly
  mips: clean and reorder the forest of macros...
  mips: consolidate __invoke_... wrappers
  ...

5 files changed, 28 insertions, 202 deletions

diff --git a/arch/tile/include/asm/Kbuild b/arch/tile/include/asm/Kbuild
index aa48b6eaff2d..24c44e93804d 100644
--- a/arch/tile/include/asm/Kbuild
+++ b/arch/tile/include/asm/Kbuild
@@ -7,6 +7,7 @@ generic-y += clkdev.h
 generic-y += emergency-restart.h
 generic-y += errno.h
 generic-y += exec.h
+generic-y += extable.h
 generic-y += fb.h
 generic-y += fcntl.h
 generic-y += hw_irq.h
diff --git a/arch/tile/include/asm/uaccess.h b/arch/tile/include/asm/uaccess.h
index a77369e91e54..a803f6bb4d92 100644
--- a/arch/tile/include/asm/uaccess.h
+++ b/arch/tile/include/asm/uaccess.h
@@ -18,15 +18,11 @@
 /*
  * User space memory access functions
  */
-#include <linux/sched.h>
 #include <linux/mm.h>
 #include <asm-generic/uaccess-unaligned.h>
 #include <asm/processor.h>
 #include <asm/page.h>
 
-#define VERIFY_READ     0
-#define VERIFY_WRITE    1
-
 /*
  * The fs value determines whether argument validity checking should be
  * performed or not.  If get_fs() == USER_DS, checking is performed, with
@@ -102,24 +98,7 @@ int __range_ok(unsigned long addr, unsigned long size);
         likely(__range_ok((unsigned long)(addr), (size)) == 0); \
 })
 
-/*
- * The exception table consists of pairs of addresses: the first is the
- * address of an instruction that is allowed to fault, and the second is
- * the address at which the program should continue.  No registers are
- * modified, so it is entirely up to the continuation code to figure out
- * what to do.
- *
- * All the routines below use bits of fixup code that are out of line
- * with the main instruction path.  This means when everything is well,
- * we don't even have to jump over them.  Further, they do not intrude
- * on our cache or tlb entries.
- */
-
-struct exception_table_entry {
-        unsigned long insn, fixup;
-};
-
-extern int fixup_exception(struct pt_regs *regs);
+#include <asm/extable.h>
 
 /*
  * This is a type: either unsigned long, if the argument fits into
@@ -334,145 +313,16 @@ extern int __put_user_bad(void)
                 ((x) = 0, -EFAULT);                                     \
 })
 
-/**
- * __copy_to_user() - copy data into user space, with less checking.
- * @to:   Destination address, in user space.
- * @from: Source address, in kernel space.
- * @n:    Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from kernel space to user space.  Caller must check
- * the specified block with access_ok() before calling this function.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- *
- * An alternate version - __copy_to_user_inatomic() - is designed
- * to be called from atomic context, typically bracketed by calls
- * to pagefault_disable() and pagefault_enable().
- */
-extern unsigned long __must_check __copy_to_user_inatomic(
-        void __user *to, const void *from, unsigned long n);
-
-static inline unsigned long __must_check
-__copy_to_user(void __user *to, const void *from, unsigned long n)
-{
-        might_fault();
-        return __copy_to_user_inatomic(to, from, n);
-}
-
-static inline unsigned long __must_check
-copy_to_user(void __user *to, const void *from, unsigned long n)
-{
-        if (access_ok(VERIFY_WRITE, to, n))
-                n = __copy_to_user(to, from, n);
-        return n;
-}
-
-/**
- * __copy_from_user() - copy data from user space, with less checking.
- * @to:   Destination address, in kernel space.
- * @from: Source address, in user space.
- * @n:    Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from user space to kernel space.  Caller must check
- * the specified block with access_ok() before calling this function.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- *
- * If some data could not be copied, this function will pad the copied
- * data to the requested size using zero bytes.
- *
- * An alternate version - __copy_from_user_inatomic() - is designed
- * to be called from atomic context, typically bracketed by calls
- * to pagefault_disable() and pagefault_enable().  This version
- * does *NOT* pad with zeros.
- */
-extern unsigned long __must_check __copy_from_user_inatomic(
-        void *to, const void __user *from, unsigned long n);
-extern unsigned long __must_check __copy_from_user_zeroing(
-        void *to, const void __user *from, unsigned long n);
-
-static inline unsigned long __must_check
-__copy_from_user(void *to, const void __user *from, unsigned long n)
-{
-       might_fault();
-       return __copy_from_user_zeroing(to, from, n);
-}
-
-static inline unsigned long __must_check
-_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);
-        else
-                memset(to, 0, n);
-        return n;
-}
-
-extern void __compiletime_error("usercopy buffer size is too small")
-__bad_copy_user(void);
-
-static inline void copy_user_overflow(int size, unsigned long count)
-{
-        WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
-}
-
-static inline unsigned long __must_check copy_from_user(void *to,
-                                          const void __user *from,
-                                          unsigned long n)
-{
-        int sz = __compiletime_object_size(to);
-
-        if (likely(sz == -1 || sz >= n))
-                n = _copy_from_user(to, from, n);
-        else if (!__builtin_constant_p(n))
-                copy_user_overflow(sz, n);
-        else
-                __bad_copy_user();
-
-        return n;
-}
+extern unsigned long __must_check
+raw_copy_to_user(void __user *to, const void *from, unsigned long n);
+extern unsigned long __must_check
+raw_copy_from_user(void *to, const void __user *from, unsigned long n);
+#define INLINE_COPY_FROM_USER
+#define INLINE_COPY_TO_USER
 
 #ifdef __tilegx__
-/**
- * __copy_in_user() - copy data within user space, with less checking.
- * @to:   Destination address, in user space.
- * @from: Source address, in user space.
- * @n:    Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from user space to user space.  Caller must check
- * the specified blocks with access_ok() before calling this function.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- */
-extern unsigned long __copy_in_user_inatomic(
+extern unsigned long raw_copy_in_user(
         void __user *to, const void __user *from, unsigned long n);
-
-static inline unsigned long __must_check
-__copy_in_user(void __user *to, const void __user *from, unsigned long n)
-{
-        might_fault();
-        return __copy_in_user_inatomic(to, from, n);
-}
-
-static inline unsigned long __must_check
-copy_in_user(void __user *to, const void __user *from, unsigned long n)
-{
-        if (access_ok(VERIFY_WRITE, to, n) && access_ok(VERIFY_READ, from, n))
-                n = __copy_in_user(to, from, n);
-        return n;
-}
 #endif
 
 
diff --git a/arch/tile/lib/exports.c b/arch/tile/lib/exports.c
index c5369fe643c7..ecce8e177e3f 100644
--- a/arch/tile/lib/exports.c
+++ b/arch/tile/lib/exports.c
@@ -38,11 +38,10 @@ EXPORT_SYMBOL(__mcount);
 
 /* arch/tile/lib/, various memcpy files */
 EXPORT_SYMBOL(memcpy);
-EXPORT_SYMBOL(__copy_to_user_inatomic);
-EXPORT_SYMBOL(__copy_from_user_inatomic);
-EXPORT_SYMBOL(__copy_from_user_zeroing);
+EXPORT_SYMBOL(raw_copy_to_user);
+EXPORT_SYMBOL(raw_copy_from_user);
 #ifdef __tilegx__
-EXPORT_SYMBOL(__copy_in_user_inatomic);
+EXPORT_SYMBOL(raw_copy_in_user);
 #endif
 
 /* hypervisor glue */
diff --git a/arch/tile/lib/memcpy_32.S b/arch/tile/lib/memcpy_32.S
index a2771ae5da53..270f1267cd18 100644
--- a/arch/tile/lib/memcpy_32.S
+++ b/arch/tile/lib/memcpy_32.S
@@ -24,7 +24,6 @@
 
 #define IS_MEMCPY         0
 #define IS_COPY_FROM_USER  1
-#define IS_COPY_FROM_USER_ZEROING  2
 #define IS_COPY_TO_USER   -1
 
         .section .text.memcpy_common, "ax"
@@ -42,40 +41,31 @@
         9
 
 
-/* __copy_from_user_inatomic takes the kernel target address in r0,
+/* raw_copy_from_user takes the kernel target address in r0,
  * the user source in r1, and the bytes to copy in r2.
  * It returns the number of uncopiable bytes (hopefully zero) in r0.
  */
-ENTRY(__copy_from_user_inatomic)
-.type __copy_from_user_inatomic, @function
-        FEEDBACK_ENTER_EXPLICIT(__copy_from_user_inatomic, \
+ENTRY(raw_copy_from_user)
+.type raw_copy_from_user, @function
+        FEEDBACK_ENTER_EXPLICIT(raw_copy_from_user, \
           .text.memcpy_common, \
-          .Lend_memcpy_common - __copy_from_user_inatomic)
+          .Lend_memcpy_common - raw_copy_from_user)
         { movei r29, IS_COPY_FROM_USER; j memcpy_common }
-        .size __copy_from_user_inatomic, . - __copy_from_user_inatomic
+        .size raw_copy_from_user, . - raw_copy_from_user
 
-/* __copy_from_user_zeroing is like __copy_from_user_inatomic, but
- * any uncopiable bytes are zeroed in the target.
- */
-ENTRY(__copy_from_user_zeroing)
-.type __copy_from_user_zeroing, @function
-        FEEDBACK_REENTER(__copy_from_user_inatomic)
-        { movei r29, IS_COPY_FROM_USER_ZEROING; j memcpy_common }
-        .size __copy_from_user_zeroing, . - __copy_from_user_zeroing
-
-/* __copy_to_user_inatomic takes the user target address in r0,
+/* raw_copy_to_user takes the user target address in r0,
  * the kernel source in r1, and the bytes to copy in r2.
  * It returns the number of uncopiable bytes (hopefully zero) in r0.
  */
-ENTRY(__copy_to_user_inatomic)
-.type __copy_to_user_inatomic, @function
-        FEEDBACK_REENTER(__copy_from_user_inatomic)
+ENTRY(raw_copy_to_user)
+.type raw_copy_to_user, @function
+        FEEDBACK_REENTER(raw_copy_from_user)
         { movei r29, IS_COPY_TO_USER; j memcpy_common }
-        .size __copy_to_user_inatomic, . - __copy_to_user_inatomic
+        .size raw_copy_to_user, . - raw_copy_to_user
 
 ENTRY(memcpy)
 .type memcpy, @function
-        FEEDBACK_REENTER(__copy_from_user_inatomic)
+        FEEDBACK_REENTER(raw_copy_from_user)
         { movei r29, IS_MEMCPY }
         .size memcpy, . - memcpy
         /* Fall through */
@@ -520,12 +510,7 @@ copy_from_user_fixup_loop:
         { bnzt r2, copy_from_user_fixup_loop }
 
 .Lcopy_from_user_fixup_zero_remainder:
-        { bbs r29, 2f }  /* low bit set means IS_COPY_FROM_USER */
-        /* byte-at-a-time loop faulted, so zero the rest. */
-        { move r3, r2; bz r2, 2f /* should be impossible, but handle it. */ }
-1:      { sb r0, zero; addi r0, r0, 1; addi r3, r3, -1 }
-        { bnzt r3, 1b }
-2:      move lr, r27
+        move lr, r27
         { move r0, r2; jrp lr }
 
 copy_to_user_fixup_loop:
diff --git a/arch/tile/lib/memcpy_user_64.c b/arch/tile/lib/memcpy_user_64.c
index 97bbb6060b25..a3fea9fd973e 100644
--- a/arch/tile/lib/memcpy_user_64.c
+++ b/arch/tile/lib/memcpy_user_64.c
@@ -51,7 +51,7 @@
                 __v;                                            \
         })
 
-#define USERCOPY_FUNC __copy_to_user_inatomic
+#define USERCOPY_FUNC raw_copy_to_user
 #define ST1(p, v) _ST((p), st1, (v))
 #define ST2(p, v) _ST((p), st2, (v))
 #define ST4(p, v) _ST((p), st4, (v))
@@ -62,7 +62,7 @@
 #define LD8 LD
 #include "memcpy_64.c"
 
-#define USERCOPY_FUNC __copy_from_user_inatomic
+#define USERCOPY_FUNC raw_copy_from_user
 #define ST1 ST
 #define ST2 ST
 #define ST4 ST
@@ -73,7 +73,7 @@
 #define LD8(p) _LD((p), ld)
 #include "memcpy_64.c"
 
-#define USERCOPY_FUNC __copy_in_user_inatomic
+#define USERCOPY_FUNC raw_copy_in_user
 #define ST1(p, v) _ST((p), st1, (v))
 #define ST2(p, v) _ST((p), st2, (v))
 #define ST4(p, v) _ST((p), st4, (v))
@@ -83,12 +83,3 @@
 #define LD4(p) _LD((p), ld4u)
 #define LD8(p) _LD((p), ld)
 #include "memcpy_64.c"
-
-unsigned long __copy_from_user_zeroing(void *to, const void __user *from,
-                                       unsigned long n)
-{
-        unsigned long rc = __copy_from_user_inatomic(to, from, n);
-        if (unlikely(rc))
-                memset(to + n - rc, 0, rc);
-        return rc;
-}