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    Subject[tip:sched/mm] powerpc: uaccess s/might_sleep/might_fault/
    Commit-ID:  1af1717dbf96eba8a74a2d6a99e75a7795075a02
    Gitweb: http://git.kernel.org/tip/1af1717dbf96eba8a74a2d6a99e75a7795075a02
    Author: Michael S. Tsirkin <mst@redhat.com>
    AuthorDate: Sun, 26 May 2013 17:31:38 +0300
    Committer: Ingo Molnar <mingo@kernel.org>
    CommitDate: Tue, 28 May 2013 09:41:09 +0200

    powerpc: uaccess s/might_sleep/might_fault/

    The only reason uaccess routines might sleep
    is if they fault. Make this explicit.

    Arnd Bergmann suggested that the following code
    if (!is_kernel_addr((unsigned long)__pu_addr))
    might_fault();
    can be further simplified by adding a version of might_fault
    that includes the kernel addr check.

    Will be considered as a further optimization in future.

    Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
    Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    Signed-off-by: Peter Zijlstra <peterz@infradead.org>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Link: http://lkml.kernel.org/r/1369577426-26721-7-git-send-email-mst@redhat.com
    Signed-off-by: Ingo Molnar <mingo@kernel.org>
    ---
    arch/powerpc/include/asm/uaccess.h | 16 ++++++++--------
    1 file changed, 8 insertions(+), 8 deletions(-)

    diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
    index 4db4959..9485b43 100644
    --- a/arch/powerpc/include/asm/uaccess.h
    +++ b/arch/powerpc/include/asm/uaccess.h
    @@ -178,7 +178,7 @@ do { \
    long __pu_err; \
    __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
    if (!is_kernel_addr((unsigned long)__pu_addr)) \
    - might_sleep(); \
    + might_fault(); \
    __chk_user_ptr(ptr); \
    __put_user_size((x), __pu_addr, (size), __pu_err); \
    __pu_err; \
    @@ -188,7 +188,7 @@ do { \
    ({ \
    long __pu_err = -EFAULT; \
    __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
    - might_sleep(); \
    + might_fault(); \
    if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
    __put_user_size((x), __pu_addr, (size), __pu_err); \
    __pu_err; \
    @@ -268,7 +268,7 @@ do { \
    const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
    __chk_user_ptr(ptr); \
    if (!is_kernel_addr((unsigned long)__gu_addr)) \
    - might_sleep(); \
    + might_fault(); \
    __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
    (x) = (__typeof__(*(ptr)))__gu_val; \
    __gu_err; \
    @@ -282,7 +282,7 @@ do { \
    const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
    __chk_user_ptr(ptr); \
    if (!is_kernel_addr((unsigned long)__gu_addr)) \
    - might_sleep(); \
    + might_fault(); \
    __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
    (x) = (__typeof__(*(ptr)))__gu_val; \
    __gu_err; \
    @@ -294,7 +294,7 @@ do { \
    long __gu_err = -EFAULT; \
    unsigned long __gu_val = 0; \
    const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
    - might_sleep(); \
    + might_fault(); \
    if (access_ok(VERIFY_READ, __gu_addr, (size))) \
    __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
    (x) = (__typeof__(*(ptr)))__gu_val; \
    @@ -419,14 +419,14 @@ static inline unsigned long __copy_to_user_inatomic(void __user *to,
    static inline unsigned long __copy_from_user(void *to,
    const void __user *from, unsigned long size)
    {
    - might_sleep();
    + might_fault();
    return __copy_from_user_inatomic(to, from, size);
    }

    static inline unsigned long __copy_to_user(void __user *to,
    const void *from, unsigned long size)
    {
    - might_sleep();
    + might_fault();
    return __copy_to_user_inatomic(to, from, size);
    }

    @@ -434,7 +434,7 @@ extern unsigned long __clear_user(void __user *addr, unsigned long size);

    static inline unsigned long clear_user(void __user *addr, unsigned long size)
    {
    - might_sleep();
    + might_fault();
    if (likely(access_ok(VERIFY_WRITE, addr, size)))
    return __clear_user(addr, size);
    if ((unsigned long)addr < TASK_SIZE) {

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      Last update: 2013-05-28 16:21    [W:3.019 / U:0.072 seconds]
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