Messages in this thread Patch in this message | | | Subject | [PATCH 2/3] x86: add some better documentation for probe_kernel_address() | From | Dave Hansen <> | Date | Fri, 22 Jul 2016 11:03:13 -0700 |
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From: Dave Hansen <dave.hansen@linux.intel.com>
probe_kernel_address() has an unfortunate name since it is used to probe kernel *and* userspace addresses. Add a comment explaining some of the situation to help the next developer who might make the silly assumption that it is for probing kernel addresses.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> ---
b/include/linux/uaccess.h | 8 ++++++++ 1 file changed, 8 insertions(+)
diff -puN include/linux/uaccess.h~pkeys-902-document-probe_kernel_address include/linux/uaccess.h --- a/include/linux/uaccess.h~pkeys-902-document-probe_kernel_address 2016-07-22 10:52:32.909347999 -0700 +++ b/include/linux/uaccess.h 2016-07-22 10:52:32.912348134 -0700 @@ -106,6 +106,14 @@ extern long strncpy_from_unsafe(char *ds * @addr: address to read from * @retval: read into this variable * + * This is safe to call on both userspace and kernel addresses. + * Kernel faults (like vmalloc faults) may be handled but do not + * sleep. + * + * If access to @addr is a userspace address and faults, we will + * enter the page fault handler, not *handling* the fault in any + * way and returning -EFAULT. + * * Returns 0 on success, or -EFAULT. */ #define probe_kernel_address(addr, retval) \ _
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