linux/kernel/bpf
Andrey Ignatov 1d11b3016c bpf: Introduce bpf_sysctl_get_current_value helper
Add bpf_sysctl_get_current_value() helper to copy current sysctl value
into provided by BPF_PROG_TYPE_CGROUP_SYSCTL program buffer.

It provides same string as user space can see by reading corresponding
file in /proc/sys/, including new line, etc.

Documentation for the new helper is provided in bpf.h UAPI.

Since current value is kept in ctl_table->data in a parsed form,
ctl_table->proc_handler() with write=0 is called to read that data and
convert it to a string. Such a string can later be parsed by a program
using helpers that will be introduced separately.

Unfortunately it's not trivial to provide API to access parsed data due to
variety of data representations (string, intvec, uintvec, ulongvec,
custom structures, even NULL, etc). Instead it's assumed that user know
how to handle specific sysctl they're interested in and appropriate
helpers can be used.

Since ctl_table->proc_handler() expects __user buffer, conversion to
__user happens for kernel allocated one where the value is stored.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12 13:54:58 -07:00
..
arraymap.c bpf: allow for key-less BTF in array map 2019-04-09 17:05:46 -07:00
bpf_lru_list.c bpf: lru: Lower the PERCPU_NR_SCANS from 16 to 4 2017-04-17 13:55:52 -04:00
bpf_lru_list.h bpf: Only set node->ref = 1 if it has not been set 2017-09-01 09:57:39 -07:00
btf.c bpf: allow for key-less BTF in array map 2019-04-09 17:05:46 -07:00
cgroup.c bpf: Introduce bpf_sysctl_get_current_value helper 2019-04-12 13:54:58 -07:00
core.c bpf: implement lookup-free direct value access for maps 2019-04-09 17:05:46 -07:00
cpumap.c xdp: fix cpumap redirect SKB creation bug 2019-03-29 12:15:02 -07:00
devmap.c bpf: devmap: fix wrong interface selection in notifier_call 2018-10-26 00:32:21 +02:00
disasm.c bpf: implement lookup-free direct value access for maps 2019-04-09 17:05:46 -07:00
disasm.h bpf: Remove struct bpf_verifier_env argument from print_bpf_insn 2018-03-23 17:38:57 +01:00
hashtab.c bpf: add program side {rd, wr}only support for maps 2019-04-09 17:05:46 -07:00
helpers.c bpf: introduce BPF_F_LOCK flag 2019-02-01 20:55:39 +01:00
inode.c bpf: fix use after free in bpf_evict_inode 2019-03-26 01:38:49 +01:00
local_storage.c bpf: add program side {rd, wr}only support for maps 2019-04-09 17:05:46 -07:00
lpm_trie.c bpf: add program side {rd, wr}only support for maps 2019-04-09 17:05:46 -07:00
Makefile bpf: add queue and stack maps 2018-10-19 13:24:31 -07:00
map_in_map.c bpf: set inner_map_meta->spin_lock_off correctly 2019-02-27 17:03:13 -08:00
map_in_map.h bpf: Add syscall lookup support for fd array and htab 2017-06-29 13:13:25 -04:00
offload.c bpf: offload: add priv field for drivers 2019-02-12 17:07:09 +01:00
percpu_freelist.c bpf: fix lockdep false positive in percpu_freelist 2019-01-31 23:18:21 +01:00
percpu_freelist.h bpf: fix lockdep false positive in percpu_freelist 2019-01-31 23:18:21 +01:00
queue_stack_maps.c bpf: add program side {rd, wr}only support for maps 2019-04-09 17:05:46 -07:00
reuseport_array.c bpf: Introduce BPF_MAP_TYPE_REUSEPORT_SOCKARRAY 2018-08-11 01:58:46 +02:00
stackmap.c bpf: fix lockdep false positive in stackmap 2019-02-11 16:36:24 +01:00
syscall.c bpf: Sysctl hook 2019-04-12 13:54:58 -07:00
tnum.c bpf/verifier: improve register value range tracking with ARSH 2018-04-29 08:45:53 -07:00
verifier.c bpf: Sysctl hook 2019-04-12 13:54:58 -07:00
xskmap.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-10-19 11:03:06 -07:00