linux/tools
Andrii Nakryiko dac645b950 libbpf: use stable map placeholder FDs
Move map creation to later during BPF object loading by pre-creating
stable placeholder FDs (utilizing memfd_create()). Use dup2()
syscall to then atomically make those placeholder FDs point to real
kernel BPF map objects.

This change allows to delay BPF map creation to after all the BPF
program relocations. That, in turn, allows to delay BTF finalization and
loading into kernel to after all the relocations as well. We'll take
advantage of the latter in subsequent patches to allow libbpf to adjust
BTF in a way that helps with BPF global function usage.

Clean up a few places where we close map->fd, which now shouldn't
happen, because map->fd should be a valid FD regardless of whether map
was created or not. Surprisingly and nicely it simplifies a bunch of
error handling code. If this change doesn't backfire, I'm tempted to
pre-create such stable FDs for other entities (progs, maybe even BTF).
We previously did some manipulations to make gen_loader work with fake
map FDs, with stable map FDs this hack is not necessary for maps (we
still have it for BTF, but I left it as is for now).

Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240104013847.3875810-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-03 21:22:49 -08:00
..
accounting
arch perf tools fixes for v6.7: 1st batch 2023-12-01 10:17:16 +09:00
bootconfig
bpf bpftool: Add support to display uprobe_multi links 2023-11-28 21:50:09 -08:00
build perf tools fixes for v6.6: 2nd batch 2023-10-30 13:46:27 -07:00
certs
cgroup iocost_monitor: improve it by adding iocg wait_ms 2023-08-08 15:43:03 -06:00
counter tools/counter: Makefile: Replace rmdir by rm to avoid make,clean failure 2023-07-24 10:29:52 -04:00
crypto/ccp crypto: ccp - Fix some unfused tests 2023-09-15 18:29:45 +08:00
debugging
edid
firewire
firmware
gpio
hv hv/hv_kvp_daemon: Some small fixes for handling NM keyfiles 2023-11-10 23:27:46 +00:00
iio tools: iio: iio_generic_buffer ensure alignment 2023-10-05 16:16:20 +01:00
include net/sched: Remove uapi support for CBQ qdisc 2024-01-02 14:25:51 +00:00
kvm/kvm_stat
laptop
leds
lib libbpf: use stable map placeholder FDs 2024-01-03 21:22:49 -08:00
memory-model
mm tools/mm: update the usage output to be more organized 2023-10-18 14:34:19 -07:00
net/ynl tools/net/ynl-gen-rst: Remove extra indentation from generated docs 2023-12-18 14:39:44 -08:00
objtool cred: get rid of CONFIG_DEBUG_CREDENTIALS 2023-12-15 14:19:48 -08:00
pci
pcmcia
perf perf list: Fix JSON segfault by setting the used skip_duplicate_pmus callback 2023-12-05 11:16:00 -08:00
power PM: tools: Fix sleepgraph syntax error 2023-11-20 17:59:58 +01:00
rcu
scripts tools/build: Fix -s detection code in tools/scripts/Makefile.include 2023-10-18 15:29:47 -07:00
spi
testing selftests/bpf: Add a selftest with > 512-byte percpu allocation size 2024-01-03 21:08:26 -08:00
thermal tools/thermal: Remove unused 'mds' and 'nrhandler' variables 2023-10-15 23:40:10 +02:00
time
tracing rtla: Fix uninitialized variable found 2023-10-30 19:00:12 +01:00
usb
verification verification/dot2k: Delete duplicate imports 2023-10-30 16:59:12 +01:00
virtio tools/virtio: Add dma sync api for virtio test 2023-10-16 05:32:23 -04:00
wmi
workqueue workqueue: Implement non-strict affinity scope for unbound workqueues 2023-08-07 15:57:25 -10:00
Makefile