The user_to_virt() function is now a straightforward wrapper around
addition, with the addend almost invariably being zero.
Remove this redundant wrapper.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Linux kernel 3.12 and earlier report a zero size via stat() for all
ACPI table files in sysfs. There is no way to determine the file size
other than by reading the file until EOF.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The statx() system call has a clean header file and a consistent
layout, but was unfortunately added only in kernel 4.11.
Using stat() or fstat() directly is extremely messy since glibc does
not necessarily use the kernel native data structures. However, as
the only current use case is to obtain the length of an open file, we
can merely provide a wrapper that does precisely this.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
