This userspace program includes UAPI headers exported to usr/include/.
'make headers' always works for the target architecture (i.e. the same
architecture as the kernel), so the sample program should be built for
the target as well. Kbuild now supports 'userprogs' for that.
I also guarded the CONFIG option by 'depends on CC_CAN_LINK' because
$(CC) may not provide libc.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The sample program is run like:
./samples/watch_queue/watch_test
and watches "/" for mount changes and the current session keyring for key
changes:
# keyctl add user a a @s
1035096409
# keyctl unlink 1035096409 @s
producing:
# ./watch_test
read() = 16
NOTIFY[000]: ty=000001 sy=02 i=00000110
KEY 2ffc2e5d change=2[linked] aux=1035096409
read() = 16
NOTIFY[000]: ty=000001 sy=02 i=00000110
KEY 2ffc2e5d change=3[unlinked] aux=1035096409
Other events may be produced, such as with a failing disk:
read() = 22
NOTIFY[000]: ty=000003 sy=02 i=00000416
USB 3-7.7 dev-reset e=0 r=0
read() = 24
NOTIFY[000]: ty=000002 sy=06 i=00000418
BLOCK 00800050 e=6[critical medium] s=64000ef8
This corresponds to:
blk_update_request: critical medium error, dev sdf, sector 1677725432 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
in dmesg.
Signed-off-by: David Howells <dhowells@redhat.com>
