linux/kernel
Yonghong Song b5ea834dde bpf: Support for new btf kind BTF_KIND_TAG
LLVM14 added support for a new C attribute ([1])
  __attribute__((btf_tag("arbitrary_str")))
This attribute will be emitted to dwarf ([2]) and pahole
will convert it to BTF. Or for bpf target, this
attribute will be emitted to BTF directly ([3], [4]).
The attribute is intended to provide additional
information for
  - struct/union type or struct/union member
  - static/global variables
  - static/global function or function parameter.

For linux kernel, the btf_tag can be applied
in various places to specify user pointer,
function pre- or post- condition, function
allow/deny in certain context, etc. Such information
will be encoded in vmlinux BTF and can be used
by verifier.

The btf_tag can also be applied to bpf programs
to help global verifiable functions, e.g.,
specifying preconditions, etc.

This patch added basic parsing and checking support
in kernel for new BTF_KIND_TAG kind.

 [1] https://reviews.llvm.org/D106614
 [2] https://reviews.llvm.org/D106621
 [3] https://reviews.llvm.org/D106622
 [4] https://reviews.llvm.org/D109560

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223015.245546-1-yhs@fb.com
2021-09-14 18:45:52 -07:00
..
bpf bpf: Support for new btf kind BTF_KIND_TAG 2021-09-14 18:45:52 -07:00
cgroup Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
configs drivers/char: remove /dev/kmem for good 2021-05-07 00:26:34 -07:00
debug isystem: trim/fixup stdarg.h and other headers 2021-08-19 09:02:55 +09:00
dma Merge branch 'stable/for-linus-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb 2021-09-03 10:34:44 -07:00
entry tick/nohz: Only check for RCU deferred wakeup on user/guest entry when needed 2021-05-31 10:14:49 +02:00
events perf: Enable branch record for software events 2021-09-13 10:53:50 -07:00
gcov Kconfig: Introduce ARCH_WANTS_NO_INSTR and CC_HAS_NO_PROFILE_FN_ATTR 2021-06-22 11:07:18 -07:00
irq powerpc updates for 5.15 2021-09-03 11:22:50 -07:00
kcsan LKMM updates: 2021-09-02 13:00:15 -07:00
livepatch livepatch: Replace deprecated CPU-hotplug functions. 2021-08-19 12:00:24 +02:00
locking Updates for locking and atomics: 2021-08-30 14:26:36 -07:00
power Merge branches 'pm-pci', 'pm-sleep', 'pm-domains' and 'powercap' 2021-08-30 19:25:42 +02:00
printk Merge branch 'rework/printk_safe-removal' into for-linus 2021-08-30 16:36:10 +02:00
rcu Updates for locking and atomics: 2021-08-30 14:26:36 -07:00
sched Power management updates for 5.15-rc1 2021-08-31 13:21:58 -07:00
time Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
trace bpf: Introduce helper bpf_get_branch_snapshot 2021-09-13 10:53:50 -07:00
.gitignore .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
acct.c kernel/acct.c: use #elif instead of #end and #elif 2020-12-15 22:46:15 -08:00
async.c kernel/async.c: remove async_unregister_domain() 2021-05-07 00:26:33 -07:00
audit_fsnotify.c audit_alloc_mark(): don't open-code ERR_CAST() 2021-02-23 10:25:27 -05:00
audit_tree.c audit: move put_tree() to avoid trim_trees refcount underflow and UAF 2021-08-24 18:52:36 -04:00
audit_watch.c fsnotify: generalize handle_inode_event() 2020-12-03 14:58:35 +01:00
audit.c lsm: separate security_task_getsecid() into subjective and objective variants 2021-03-22 15:23:32 -04:00
audit.h audit: add header protection to kernel/audit.h 2021-07-19 22:38:24 -04:00
auditfilter.c lsm: separate security_task_getsecid() into subjective and objective variants 2021-03-22 15:23:32 -04:00
auditsc.c audit: remove trailing spaces and tabs 2021-06-10 20:59:05 -04:00
backtracetest.c
bounds.c
capability.c capability: handle idmapped mounts 2021-01-24 14:27:16 +01:00
cfi.c cfi: Use rcu_read_{un}lock_sched_notrace 2021-08-11 13:11:12 -07:00
compat.c
configs.c
context_tracking.c
cpu_pm.c PM: cpu: Make notifier chain use a raw_spinlock_t 2021-08-16 18:55:32 +02:00
cpu.c cpu/hotplug: Add debug printks for hotplug callback failures 2021-08-10 18:31:32 +02:00
crash_core.c kdump: use vmlinux_build_id to simplify 2021-07-08 11:48:22 -07:00
crash_dump.c
cred.c ucounts: Increase ucounts reference counter before the security hook 2021-08-23 16:13:04 -05:00
delayacct.c delayacct: Add sysctl to enable at runtime 2021-05-12 11:43:25 +02:00
dma.c
exec_domain.c
exit.c io_uring: remove files pointer in cancellation functions 2021-08-23 13:10:37 -06:00
extable.c
fail_function.c fault-injection: handle EI_ETYPE_TRUE 2020-12-15 22:46:19 -08:00
fork.c Merge tag 'denywrite-for-5.15' of git://github.com/davidhildenbrand/linux 2021-09-04 11:35:47 -07:00
freezer.c sched: Add get_current_state() 2021-06-18 11:43:08 +02:00
futex.c futex: Prevent requeue_pi() lock nesting issue on RT 2021-08-17 19:05:59 +02:00
gen_kheaders.sh kbuild: clean up ${quiet} checks in shell scripts 2021-05-27 04:01:50 +09:00
groups.c groups: simplify struct group_info allocation 2021-02-26 09:41:03 -08:00
hung_task.c Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
iomem.c
irq_work.c irq_work: Make irq_work_queue() NMI-safe again 2021-06-10 10:00:08 +02:00
jump_label.c jump_label: Fix jump_label_text_reserved() vs __init 2021-07-05 10:46:20 +02:00
kallsyms.c module: add printk formats to add module build ID to stacktraces 2021-07-08 11:48:22 -07:00
kcmp.c Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:36:48 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/rwlock: Provide RT variant 2021-08-17 17:50:51 +02:00
Kconfig.preempt sched/core: Disable CONFIG_SCHED_CORE by default 2021-06-28 22:43:05 +02:00
kcov.c kernel: make kcov_common_handle consider the current context 2020-11-02 18:00:20 -08:00
kexec_core.c Merge branch 'rework/printk_safe-removal' into for-linus 2021-08-30 16:36:10 +02:00
kexec_elf.c
kexec_file.c kernel: kexec_file: fix error return code of kexec_calculate_store_digests() 2021-05-07 00:26:32 -07:00
kexec_internal.h kexec: move machine_kexec_post_load() to public interface 2021-02-22 12:33:26 +00:00
kexec.c
kheaders.c
kmod.c modules: add CONFIG_MODPROBE_PATH 2021-05-07 00:26:33 -07:00
kprobes.c Locking fixes: 2021-07-11 11:06:09 -07:00
ksysfs.c
kthread.c Merge branch 'akpm' (patches from Andrew) 2021-06-29 17:29:11 -07:00
latencytop.c
Makefile kbuild: update config_data.gz only when the content of .config is changed 2021-05-02 00:43:35 +09:00
module_signature.c module: harden ELF info handling 2021-01-19 10:24:45 +01:00
module_signing.c module: harden ELF info handling 2021-01-19 10:24:45 +01:00
module-internal.h
module.c printk: Userspace format indexing support 2021-07-19 11:57:48 +02:00
notifier.c notifier: Remove atomic_notifier_call_chain_robust() 2021-08-16 18:55:32 +02:00
nsproxy.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
padata.c padata: Remove repeated verbose license text 2021-08-27 16:30:18 +08:00
panic.c Merge branch 'rework/printk_safe-removal' into for-linus 2021-08-30 16:36:10 +02:00
params.c params: lift param_set_uint_minmax to common code 2021-08-16 14:42:22 +02:00
pid_namespace.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
pid.c kernel/pid.c: implement additional checks upon pidfd_create() parameters 2021-08-10 12:53:07 +02:00
profile.c kernel: Initialize cpumask before parsing 2021-04-10 13:35:54 +02:00
ptrace.c sched: Change task_struct::state 2021-06-18 11:43:09 +02:00
range.c kernel.h: split out min()/max() et al. helpers 2020-10-16 11:11:19 -07:00
reboot.c reboot: Add hardware protection power-off 2021-06-21 13:08:36 +01:00
regset.c
relay.c relay: allow the use of const callback structs 2020-12-15 22:46:18 -08:00
resource_kunit.c resource: provide meaningful MODULE_LICENSE() in test suite 2020-11-25 18:52:35 +01:00
resource.c kernel/resource: fix return code check in __request_free_mem_region 2021-05-14 19:41:32 -07:00
rseq.c rseq: Optimise rseq_get_rseq_cs() and clear_rseq_cs() 2021-04-14 18:04:09 +02:00
scftorture.c scftorture: Avoid NULL pointer exception on early exit 2021-07-27 11:39:30 -07:00
scs.c scs: switch to vmapped shadow stacks 2020-12-01 10:30:28 +00:00
seccomp.c Merge branch 'exit-cleanups-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-09-01 14:52:05 -07:00
signal.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
smp.c smp: Fix all kernel-doc warnings 2021-08-11 14:47:16 +02:00
smpboot.c smpboot: Replace deprecated CPU-hotplug functions. 2021-08-10 14:57:42 +02:00
smpboot.h
softirq.c genirq: Change force_irqthreads to a static key 2021-08-10 22:50:07 +02:00
stackleak.c
stacktrace.c
static_call.c static_call: Fix static_call_text_reserved() vs __init 2021-07-05 10:46:33 +02:00
stop_machine.c stop_machine: Add caller debug info to queue_stop_cpus_work 2021-03-23 16:01:58 +01:00
sys_ni.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
sys.c Merge tag 'denywrite-for-5.15' of git://github.com/davidhildenbrand/linux 2021-09-04 11:35:47 -07:00
sysctl-test.c kernel/sysctl-test: Remove some casts which are no-longer required 2021-06-23 16:41:24 -06:00
sysctl.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
task_work.c kasan: record task_work_add() call stack 2021-04-30 11:20:42 -07:00
taskstats.c treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
test_kprobes.c
torture.c torture: Replace deprecated CPU-hotplug functions. 2021-08-10 10:48:07 -07:00
tracepoint.c tracepoint: Fix kerneldoc comments 2021-08-16 11:39:51 -04:00
tsacct.c
ucount.c ucounts: add missing data type changes 2021-08-09 15:45:02 -05:00
uid16.c
uid16.h
umh.c kernel/umh.c: fix some spelling mistakes 2021-05-07 00:26:34 -07:00
up.c A set of locking related fixes and updates: 2021-05-09 13:07:03 -07:00
user_namespace.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
user-return-notifier.c
user.c Reimplement RLIMIT_MEMLOCK on top of ucounts 2021-04-30 14:14:02 -05:00
usermode_driver.c Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-07-03 11:41:14 -07:00
utsname_sysctl.c
utsname.c
watch_queue.c watch_queue: rectify kernel-doc for init_watch() 2021-01-26 11:16:34 +00:00
watchdog_hld.c
watchdog.c kernel: watchdog: modify the explanation related to watchdog thread 2021-06-29 10:53:46 -07:00
workqueue_internal.h workqueue: Assign a color to barrier work items 2021-08-17 07:49:10 -10:00
workqueue.c workqueue: Assign a color to barrier work items 2021-08-17 07:49:10 -10:00