[PATCH v2 4/5] uaccess: clarify that uaccess may only sleep if pagefaults are not disabled
In general, non-atomic variants of user access functions may not sleep if pagefaults are disabled. Let's update all relevant comments in uaccess code. This also refelects the might_sleep() checks in might_fault(). Signed-off-by: David Hildenbrand --- arch/avr32/include/asm/uaccess.h | 12 ++ arch/hexagon/include/asm/uaccess.h| 3 ++- arch/m32r/include/asm/uaccess.h | 30 +++ arch/microblaze/include/asm/uaccess.h | 6 +++-- arch/mips/include/asm/uaccess.h | 45 +++ arch/s390/include/asm/uaccess.h | 15 arch/score/include/asm/uaccess.h | 15 arch/tile/include/asm/uaccess.h | 21 ++-- arch/x86/include/asm/uaccess.h| 15 arch/x86/include/asm/uaccess_32.h | 6 +++-- arch/x86/lib/usercopy_32.c| 6 +++-- lib/strnlen_user.c| 6 +++-- 12 files changed, 120 insertions(+), 60 deletions(-) diff --git a/arch/avr32/include/asm/uaccess.h b/arch/avr32/include/asm/uaccess.h index 245b2ee..6b6dd58 100644 --- a/arch/avr32/include/asm/uaccess.h +++ b/arch/avr32/include/asm/uaccess.h @@ -97,7 +97,8 @@ static inline __kernel_size_t __copy_from_user(void *to, * @x: Value to copy to user space. * @ptr: Destination address, in user space. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * This macro copies a single simple value from kernel space to user * space. It supports simple types like char and int, but not larger @@ -116,7 +117,8 @@ static inline __kernel_size_t __copy_from_user(void *to, * @x: Variable to store result. * @ptr: Source address, in user space. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * This macro copies a single simple variable from user space to kernel * space. It supports simple types like char and int, but not larger @@ -136,7 +138,8 @@ static inline __kernel_size_t __copy_from_user(void *to, * @x: Value to copy to user space. * @ptr: Destination address, in user space. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * This macro copies a single simple value from kernel space to user * space. It supports simple types like char and int, but not larger @@ -158,7 +161,8 @@ static inline __kernel_size_t __copy_from_user(void *to, * @x: Variable to store result. * @ptr: Source address, in user space. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * This macro copies a single simple variable from user space to kernel * space. It supports simple types like char and int, but not larger diff --git a/arch/hexagon/include/asm/uaccess.h b/arch/hexagon/include/asm/uaccess.h index e4127e4..af98618 100644 --- a/arch/hexagon/include/asm/uaccess.h +++ b/arch/hexagon/include/asm/uaccess.h @@ -36,7 +36,8 @@ * @addr: User space pointer to start of block to check * @size: Size of block to check * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * Checks if a pointer to a block of memory in user space is valid. * diff --git a/arch/m32r/include/asm/uaccess.h b/arch/m32r/include/asm/uaccess.h index 84fe7ba..83bfa33 100644 --- a/arch/m32r/include/asm/uaccess.h +++ b/arch/m32r/include/asm/uaccess.h @@ -91,7 +91,8 @@ static inline void set_fs(mm_segment_t s) * @addr: User space pointer to start of block to check * @size: Size of block to check * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * Checks if a pointer to a block of memory in user space is valid. * @@ -155,7 +156,8 @@ extern int fixup_exception(struct pt_regs *regs); * @x: Variable to store result. * @ptr: Source address, in user space. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * This macro copies a single simple variable from user space to kernel * space. It supports simple types like char and int, but not larger @@ -175,7 +177,8 @@ extern int fixup_exception(struct pt_regs *regs); * @x: Value to copy to user space. * @ptr: Destination address, in user space. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * This macro copies a single simple value from kernel
[PATCH v2 4/5] uaccess: clarify that uaccess may only sleep if pagefaults are not disabled
In general, non-atomic variants of user access functions may not sleep if pagefaults are disabled. Let's update all relevant comments in uaccess code. This also refelects the might_sleep() checks in might_fault(). Signed-off-by: David Hildenbrand d...@linux.vnet.ibm.com --- arch/avr32/include/asm/uaccess.h | 12 ++ arch/hexagon/include/asm/uaccess.h| 3 ++- arch/m32r/include/asm/uaccess.h | 30 +++ arch/microblaze/include/asm/uaccess.h | 6 +++-- arch/mips/include/asm/uaccess.h | 45 +++ arch/s390/include/asm/uaccess.h | 15 arch/score/include/asm/uaccess.h | 15 arch/tile/include/asm/uaccess.h | 21 ++-- arch/x86/include/asm/uaccess.h| 15 arch/x86/include/asm/uaccess_32.h | 6 +++-- arch/x86/lib/usercopy_32.c| 6 +++-- lib/strnlen_user.c| 6 +++-- 12 files changed, 120 insertions(+), 60 deletions(-) diff --git a/arch/avr32/include/asm/uaccess.h b/arch/avr32/include/asm/uaccess.h index 245b2ee..6b6dd58 100644 --- a/arch/avr32/include/asm/uaccess.h +++ b/arch/avr32/include/asm/uaccess.h @@ -97,7 +97,8 @@ static inline __kernel_size_t __copy_from_user(void *to, * @x: Value to copy to user space. * @ptr: Destination address, in user space. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * This macro copies a single simple value from kernel space to user * space. It supports simple types like char and int, but not larger @@ -116,7 +117,8 @@ static inline __kernel_size_t __copy_from_user(void *to, * @x: Variable to store result. * @ptr: Source address, in user space. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * This macro copies a single simple variable from user space to kernel * space. It supports simple types like char and int, but not larger @@ -136,7 +138,8 @@ static inline __kernel_size_t __copy_from_user(void *to, * @x: Value to copy to user space. * @ptr: Destination address, in user space. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * This macro copies a single simple value from kernel space to user * space. It supports simple types like char and int, but not larger @@ -158,7 +161,8 @@ static inline __kernel_size_t __copy_from_user(void *to, * @x: Variable to store result. * @ptr: Source address, in user space. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * This macro copies a single simple variable from user space to kernel * space. It supports simple types like char and int, but not larger diff --git a/arch/hexagon/include/asm/uaccess.h b/arch/hexagon/include/asm/uaccess.h index e4127e4..af98618 100644 --- a/arch/hexagon/include/asm/uaccess.h +++ b/arch/hexagon/include/asm/uaccess.h @@ -36,7 +36,8 @@ * @addr: User space pointer to start of block to check * @size: Size of block to check * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * Checks if a pointer to a block of memory in user space is valid. * diff --git a/arch/m32r/include/asm/uaccess.h b/arch/m32r/include/asm/uaccess.h index 84fe7ba..83bfa33 100644 --- a/arch/m32r/include/asm/uaccess.h +++ b/arch/m32r/include/asm/uaccess.h @@ -91,7 +91,8 @@ static inline void set_fs(mm_segment_t s) * @addr: User space pointer to start of block to check * @size: Size of block to check * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * Checks if a pointer to a block of memory in user space is valid. * @@ -155,7 +156,8 @@ extern int fixup_exception(struct pt_regs *regs); * @x: Variable to store result. * @ptr: Source address, in user space. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * This macro copies a single simple variable from user space to kernel * space. It supports simple types like char and int, but not larger @@ -175,7 +177,8 @@ extern int fixup_exception(struct pt_regs *regs); * @x: Value to copy to user space. * @ptr: Destination address, in user space. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are not + * disabled. * * This macro copies a single
