From: Jason Wessel Subject: [PATCH] maccess,probe_kernel: Allow arch specific override probe_kernel_(read|write) Some archs such as blackfin, would like to have an arch specific probe_kernel_read() and probe_kernel_write() implementation which can fall back to the generic implementation if no special operations are needed. CC: Mike Frysinger CC: Thomas Gleixner CC: Ingo Molnar Signed-off-by: Jason Wessel --- include/linux/uaccess.h | 4 +++- mm/maccess.c | 11 +++++++++-- 2 files changed, 12 insertions(+), 3 deletions(-) --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -94,6 +94,7 @@ static inline unsigned long __copy_from_ * happens, handle that and return -EFAULT. */ extern long probe_kernel_read(void *dst, void *src, size_t size); +extern long __probe_kernel_read(void *dst, void *src, size_t size); /* * probe_kernel_write(): safely attempt to write to a location @@ -104,6 +105,7 @@ extern long probe_kernel_read(void *dst, * Safely write to address @dst from the buffer at @src. If a kernel fault * happens, handle that and return -EFAULT. */ -extern long probe_kernel_write(void *dst, void *src, size_t size); +extern long notrace probe_kernel_write(void *dst, void *src, size_t size); +extern long notrace __probe_kernel_write(void *dst, void *src, size_t size); #endif /* __LINUX_UACCESS_H__ */ --- a/mm/maccess.c +++ b/mm/maccess.c @@ -14,7 +14,11 @@ * Safely read from address @src to the buffer at @dst. If a kernel fault * happens, handle that and return -EFAULT. */ -long probe_kernel_read(void *dst, void *src, size_t size) + +long __weak probe_kernel_read(void *dst, void *src, size_t size) + __attribute__((alias("__probe_kernel_read"))); + +long __probe_kernel_read(void *dst, void *src, size_t size) { long ret; mm_segment_t old_fs = get_fs(); @@ -39,7 +43,10 @@ EXPORT_SYMBOL_GPL(probe_kernel_read); * Safely write to address @dst from the buffer at @src. If a kernel fault * happens, handle that and return -EFAULT. */ -long notrace __weak probe_kernel_write(void *dst, void *src, size_t size) +long __weak probe_kernel_write(void *dst, void *src, size_t size) + __attribute__((alias("__probe_kernel_write"))); + +long notrace __probe_kernel_write(void *dst, void *src, size_t size) { long ret; mm_segment_t old_fs = get_fs();