The list of error codes in the man page was out of date with respect to the current state of the kernel. Some errors were partially / incorrectly described. Update the error code listing, so it matches the current state of the kernel, and correctly describes all the errors. Signed-off-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx> --- man2/ioctl_userfaultfd.2 | 33 +++++++++++++++++++-------------- 1 file changed, 19 insertions(+), 14 deletions(-) diff --git a/man2/ioctl_userfaultfd.2 b/man2/ioctl_userfaultfd.2 index 82aee667c..40528001e 100644 --- a/man2/ioctl_userfaultfd.2 +++ b/man2/ioctl_userfaultfd.2 @@ -413,8 +413,6 @@ On error, \-1 is returned and .I errno is set to indicate the error. Possible errors include: -.\" FIXME Is the following error list correct? -.\" .TP .B EBUSY A mapping in the specified range is registered with another @@ -433,21 +431,28 @@ field; or the field was zero. .TP .B EINVAL -There is no mapping in the specified address range. -.TP -.B EINVAL -.I range.start +The specified address range was invalid. +More specifically, +no mapping exists in the given range, +or the mapping that exists there is invalid +(e.g. unsupported type of memory), +or the range values +.RI ( range.start +or +.IR range.len ) +are not multiples of the relevant page size, or .I range.len -is not a multiple of the system page size; or, -.I range.len -is zero; or these fields are otherwise invalid. +is zero. .TP -.B EINVAL -There as an incompatible mapping in the specified address range. -.\" Mike Rapoport: -.\" ENOMEM if the process is exiting and the -.\" mm_struct has gone by the time userfault grabs it. +.B ENOMEM +The process is exiting, +and its address space has already been torn down +when userfaultfd attempts to reference it. +.TP +.B EPERM +The userfaultfd would allow writing to a file backing the mapping, +but the calling process lacks such write permissions. .SS UFFDIO_UNREGISTER (Since Linux 4.3.) Unregister a memory address range from userfaultfd. -- 2.42.0.655.g421f12c284-goog
