maccess.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10

    1 /*
    2  * Access kernel memory without faulting.
    3  */
    4 #include <linux/export.h>
    5 #include <linux/mm.h>
    6 #include <linux/uaccess.h>
    7 
    8 /**
    9  * probe_kernel_read(): safely attempt to read from a location
   10  * @dst: pointer to the buffer that shall take the data
   11  * @src: address to read from
   12  * @size: size of the data chunk
   13  *
   14  * Safely read from address @src to the buffer at @dst.  If a kernel fault
   15  * happens, handle that and return -EFAULT.
   16  */
   17 
   18 long __weak probe_kernel_read(void *dst, const void *src, size_t size)
   19     __attribute__((alias("__probe_kernel_read")));
   20 
   21 long __probe_kernel_read(void *dst, const void *src, size_t size)
   22 {
   23         long ret;
   24         mm_segment_t old_fs = get_fs();
   25 
   26         set_fs(KERNEL_DS);
   27         pagefault_disable();
   28         ret = __copy_from_user_inatomic(dst,
   29                         (__force const void __user *)src, size);
   30         pagefault_enable();
   31         set_fs(old_fs);
   32 
   33         return ret ? -EFAULT : 0;
   34 }
   35 EXPORT_SYMBOL_GPL(probe_kernel_read);
   36 
   37 /**
   38  * probe_kernel_write(): safely attempt to write to a location
   39  * @dst: address to write to
   40  * @src: pointer to the data that shall be written
   41  * @size: size of the data chunk
   42  *
   43  * Safely write to address @dst from the buffer at @src.  If a kernel fault
   44  * happens, handle that and return -EFAULT.
   45  */
   46 long __weak probe_kernel_write(void *dst, const void *src, size_t size)
   47     __attribute__((alias("__probe_kernel_write")));
   48 
   49 long __probe_kernel_write(void *dst, const void *src, size_t size)
   50 {
   51         long ret;
   52         mm_segment_t old_fs = get_fs();
   53 
   54         set_fs(KERNEL_DS);
   55         pagefault_disable();
   56         ret = __copy_to_user_inatomic((__force void __user *)dst, src, size);
   57         pagefault_enable();
   58         set_fs(old_fs);
   59 
   60         return ret ? -EFAULT : 0;
   61 }
   62 EXPORT_SYMBOL_GPL(probe_kernel_write);

Cache object: fe2c62e8b213d91a2ab32bdc6d085b31

[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.

FreeBSD/Linux Kernel Cross Reference sys/mm/maccess.c

FreeBSD/Linux Kernel Cross Reference
sys/mm/maccess.c