Daniel Borkmann
87df15de44
bpf: add syscall side map freeze support ...
This patch adds a new BPF_MAP_FREEZE command which allows to
"freeze" the map globally as read-only / immutable from syscall
side.
Map permission handling has been refactored into map_get_sys_perms()
and drops FMODE_CAN_WRITE in case of locked map. Main use case is
to allow for setting up .rodata sections from the BPF ELF which
are loaded into the kernel, meaning BPF loader first allocates
map, sets up map value by copying .rodata section into it and once
complete, it calls BPF_MAP_FREEZE on the map fd to prevent further
modifications.
Right now BPF_MAP_FREEZE only takes map fd as argument while remaining
bpf_attr members are required to be zero. I didn't add write-only
locking here as counterpart since I don't have a concrete use-case
for it on my side, and I think it makes probably more sense to wait
once there is actually one. In that case bpf_attr can be extended
as usual with a flag field and/or others where flag 0 means that
we lock the map read-only hence this doesn't prevent to add further
extensions to BPF_MAP_FREEZE upon need.
A map creation flag like BPF_F_WRONCE was not considered for couple
of reasons: i) in case of a generic implementation, a map can consist
of more than just one element, thus there could be multiple map
updates needed to set the map into a state where it can then be
made immutable, ii) WRONCE indicates exact one-time write before
it is then set immutable. A generic implementation would set a bit
atomically on map update entry (if unset), indicating that every
subsequent update from then onwards will need to bail out there.
However, map updates can fail, so upon failure that flag would need
to be unset again and the update attempt would need to be repeated
for it to be eventually made immutable. While this can be made
race-free, this approach feels less clean and in combination with
reason i), it's not generic enough. A dedicated BPF_MAP_FREEZE
command directly sets the flag and caller has the guarantee that
map is immutable from syscall side upon successful return for any
future syscall invocations that would alter the map state, which
is also more intuitive from an API point of view. A command name
such as BPF_MAP_LOCK has been avoided as it's too close with BPF
map spin locks (which already has BPF_F_LOCK flag). BPF_MAP_FREEZE
is so far only enabled for privileged users.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-09 17:05:46 -07:00
bpf: add syscall side map freeze support
2019-04-09 17:05:46 -07:00
Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-03-12 14:08:19 -07:00
kvm_config: add CONFIG_VIRTIO_MENU
2018-10-24 20:55:56 -04:00
kdb: use bool for binary state indicators
2018-12-30 08:31:52 +00:00
memblock: drop memblock_alloc_*_nopanic() variants
2019-03-12 10:04:02 -07:00
perf/core improvements and fixes:
2019-03-22 22:50:41 +01:00
kernel/gcov/gcc_3_4.c: use struct_size() in kzalloc()
2019-03-07 18:32:02 -08:00
genirq: Mark expected switch case fall-through
2019-03-23 12:32:01 +01:00
Merge branch 'for-5.1/atomic-replace' into for-linus
2019-03-05 15:56:59 +01:00
locking/lockdep: Only call init_rcu_head() after RCU has been initialized
2019-03-09 14:15:51 +01:00
treewide: add checks for the return value of memblock_alloc*()
2019-03-12 10:04:02 -07:00
fbdev changes for v5.1:
2019-03-15 14:22:59 -07:00
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-03-06 07:59:36 -08:00
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-03-24 11:42:10 -07:00
time/jiffies: Make refined_jiffies static
2019-03-22 13:38:26 +01:00
ftrace: Fix warning using plain integer as NULL & spelling corrections
2019-03-26 08:35:36 -04:00
kernel/configs: use .incbin directive to embed config_data.gz
2019-03-07 18:32:02 -08:00
async: Add support for queueing on specific NUMA node
2019-01-31 14:20:54 +01:00
audit: remove audit_context when CONFIG_ AUDIT and not AUDITSYSCALL
2019-02-03 17:49:35 -05:00
audit: hide auditsc_get_stamp and audit_serial prototypes
2019-02-07 21:44:27 -05:00
audit: add syscall information to CONFIG_CHANGE records
2019-01-18 17:53:29 -05:00
audit: hand taken context to audit_kill_trees for syscall logging
2019-01-14 18:01:05 -05:00
audit: add syscall information to CONFIG_CHANGE records
2019-01-18 17:53:29 -05:00
audit: mark expected switch fall-through
2019-02-12 20:17:13 -05:00
audit: remove audit_context when CONFIG_ AUDIT and not AUDITSYSCALL
2019-02-03 17:49:35 -05:00
kbuild: fix kernel/bounds.c 'W=1' warning
2018-10-31 08:54:14 -07:00
LSM: add SafeSetID module that gates setid calls
2019-01-25 11:22:43 -08:00
time: make adjtime compat handling available for 32 bit
2019-02-07 00:13:27 +01:00
kernel/configs: use .incbin directive to embed config_data.gz
2019-03-07 18:32:02 -08:00
Linux 5.0-rc5
2019-02-04 08:57:24 +01:00
kexec: export PG_offline to VMCOREINFO
2019-03-05 21:07:14 -08:00
SELinux: Remove cred security blob poisoning
2019-01-08 13:18:44 -08:00
delayacct: track delays from thrashing cache pages
2018-10-26 16:26:32 -07:00
Merge branch 'for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2019-03-07 10:11:41 -08:00
kernel/fail_function.c: remove meaningless null pointer check before debugfs_remove_recursive
2018-10-31 08:54:12 -07:00
5.1 Merge Window Pull Request
2019-03-09 15:53:03 -08:00
futex: Ensure that futex address is aligned in handle_futex_death()
2019-03-22 13:05:26 +01:00
kernel/hung_task.c: Use continuously blocked time when reporting.
2019-03-07 18:31:59 -08:00
jump_label: move 'asm goto' support test to Kconfig
2019-01-06 09:46:51 +09:00
bpf: Add module name [bpf] to ksymbols for bpf programs
2019-01-21 17:38:56 -03:00
bpf: introduce bpf_spin_lock
2019-02-01 20:55:38 +01:00
kconfig: warn no new line at end of file
2018-12-15 17:44:35 +09:00
kcov: convert kcov.refcount to refcount_t
2019-03-07 18:32:02 -08:00
mm: convert totalram_pages and totalhigh_pages variables to atomic
2018-12-28 12:11:47 -08:00
kexec_file: kexec_walk_memblock() only walks a dedicated region at kdump
2018-12-06 14:38:50 +00:00
kprobes: Search non-suffixed symbol in blacklist
2019-02-13 08:16:40 +01:00
Merge branch 'akpm' (patches from Andrew)
2019-03-06 10:31:36 -08:00
kernel/configs: use .incbin directive to embed config_data.gz
2019-03-07 18:32:02 -08:00
mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
2018-12-28 12:11:52 -08:00
dynamic_debug: add static inline stub for ddebug_add_module
2019-03-07 18:32:00 -08:00
modsign: use all trusted keys to verify module signature
2018-11-07 14:41:41 +01:00
padata: clean an indentation issue, remove extraneous space
2018-11-16 14:11:04 +08:00
kernel/panic.c: taint: fix debugfs_simple_attr.cocci warnings
2019-03-07 18:31:59 -08:00
Fix failure path in alloc_pid()
2018-12-28 12:42:30 -08:00
mm: remove include/linux/bootmem.h
2018-10-31 08:54:16 -07:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-03-12 13:27:20 -07:00
device-dax for 5.1
2019-03-16 13:05:32 -07:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2019-03-07 11:44:01 -08:00
pidfd patches for v5.1-rc1
2019-03-16 13:47:14 -07:00
cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM
2019-01-30 19:27:00 +01:00
softirq: Don't skip softirq execution when softirq thread is parking
2019-02-10 21:51:39 +01:00
stackleak: Mark stackleak_track_stack() as notrace
2018-12-05 19:31:44 -08:00
Merge branch 'akpm' (patches from Andrew)
2019-03-07 19:25:37 -08:00
pidfd patches for v5.1-rc1
2019-03-16 13:47:14 -07:00
kernel/sysctl.c: define minmax conv functions in terms of non-minmax versions
2019-03-12 10:04:00 -07:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
genetlink: make policy common to family
2019-03-22 10:38:23 -04:00
Merge branches 'doc.2019.01.26a', 'fixes.2019.01.26a', 'sil.2019.01.26a', 'spdx.2019.02.09a', 'srcu.2019.01.26a' and 'torture.2019.01.26a' into HEAD
2019-02-09 08:47:52 -08:00
tracing: Replace synchronize_sched() and call_rcu_sched()
2018-11-27 09:21:41 -08:00
umh: add exit routine for UMH process
2019-01-11 18:05:40 -08:00
userns: also map extents in the reverse map to kernel IDs
2018-11-07 23:51:16 -06:00
watchdog/core: Make variables static
2019-03-22 13:40:17 +01:00
workqueue: Only unregister a registered lockdep key
2019-03-21 12:00:18 +01:00
psi: fix aggregation idle shut-off
2019-02-01 15:46:23 -08:00
87df15de44