linux/samples
Jesper Dangaard Brouer 7bc57950bd samples/bpf: bpf_load.c order of prog_fd[] should correspond with ELF order
An eBPF ELF file generated with LLVM can contain several program
section, which can be used for bpf tail calls.  The bpf prog file
descriptors are accessible via array prog_fd[].

At-least XDP samples assume ordering, and uses prog_fd[0] is the main
XDP program to attach.  The actual order of array prog_fd[] depend on
whether or not a bpf program section is referencing any maps or not.
Not using a map result in being loaded/processed after all other
prog section.  Thus, this can lead to some very strange and hard to
debug situation, as the user can only see a FD and cannot correlated
that with the ELF section name.

The fix is rather simple, and even removes duplicate memcmp code.
Simply load program sections as the last step, instead of
load_and_attach while processing the relocation section.

When working with tail calls, it become even more essential that the
order of prog_fd[] is consistant, like the current dependency of the
map_fd[] order.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-31 12:59:20 -04:00
..
auxdisplay samples: move auxdisplay example code from Documentation 2016-09-23 11:52:32 -06:00
blackfin samples: move blackfin gptimers-example from Documentation 2016-10-10 07:12:02 -06:00
bpf samples/bpf: bpf_load.c order of prog_fd[] should correspond with ELF order 2017-05-31 12:59:20 -04:00
configfs configfs: remove old API 2015-10-13 22:17:57 -07:00
connector make use of make variable CURDIR instead of calling pwd 2016-12-11 12:12:56 +01:00
hidraw HID: samples/hidraw: make it possible to select device 2015-03-15 10:11:21 -04:00
hw_breakpoint perf: Add context field to perf_event 2011-07-01 11:06:38 +02:00
kdb kdb: Add kdb kernel module sample 2010-10-29 13:14:39 -05:00
kfifo kfifo API type safety 2013-11-15 09:32:23 +09:00
kobject samples/kobject: be explicit in the module license 2015-03-25 13:41:42 +01:00
kprobes samples/kretprobe: fix the wrong type 2016-08-04 08:50:07 -04:00
livepatch livepatch: allow removal of a disabled patch 2017-03-08 09:38:43 +01:00
mei mei: drop the TODO from samples 2017-04-26 11:38:56 +02:00
mic/mpssd samples: move mic/mpssd example code from Documentation 2016-09-20 12:38:48 -06:00
pktgen samples: Add an IPv6 '-6' option to the pktgen scripts 2016-07-20 22:16:02 -07:00
rpmsg rpmsg: Allow callback to return errors 2016-09-08 22:15:25 -07:00
seccomp samples/seccomp: fix 64-bit comparison macros 2017-01-09 17:22:03 +11:00
statx statx: Include a mask for stx_attributes in struct statx 2017-04-03 01:06:00 -04:00
timers samples: move timers example code from Documentation 2016-09-23 11:51:58 -06:00
trace_events sched/core: Remove the tsk_cpus_allowed() wrapper 2017-03-02 08:42:24 +01:00
trace_printk tracing: Add trace_printk sample code 2016-06-20 09:54:21 -04:00
uhid HID: uhid: improve uhid example client 2013-09-04 11:35:14 +02:00
v4l [media] vb2: replace void *alloc_ctxs by struct device *alloc_devs 2016-07-08 14:45:07 -03:00
vfio-mdev vfio-mdev: remove some dead code 2017-01-11 12:12:37 -07:00
watchdog samples: move watchdog example code from Documentation 2016-09-23 11:52:14 -06:00
Kconfig statx: Add a system call to make enhanced file info available 2017-03-02 20:51:15 -05:00
Makefile statx: Add a system call to make enhanced file info available 2017-03-02 20:51:15 -05:00