linux/kernel
Alexei Starovoitov 1e89106da2 bpf: Add bpf_core_add_cands() and wire it into bpf_core_apply_relo_insn().
Given BPF program's BTF root type name perform the following steps:
. search in vmlinux candidate cache.
. if (present in cache and candidate list >= 1) return candidate list.
. do a linear search through kernel BTFs for possible candidates.
. regardless of number of candidates found populate vmlinux cache.
. if (candidate list >= 1) return candidate list.
. search in module candidate cache.
. if (present in cache) return candidate list (even if list is empty).
. do a linear search through BTFs of all kernel modules
  collecting candidates from all of them.
. regardless of number of candidates found populate module cache.
. return candidate list.
Then wire the result into bpf_core_apply_relo_insn().

When BPF program is trying to CO-RE relocate a type
that doesn't exist in either vmlinux BTF or in modules BTFs
these steps will perform 2 cache lookups when cache is hit.

Note the cache doesn't prevent the abuse by the program that might
have lots of relocations that cannot be resolved. Hence cond_resched().

CO-RE in the kernel requires CAP_BPF, since BTF loading requires it.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211201181040.23337-9-alexei.starovoitov@gmail.com
2021-12-02 11:18:35 -08:00
..
bpf bpf: Add bpf_core_add_cands() and wire it into bpf_core_apply_relo_insn(). 2021-12-02 11:18:35 -08:00
cgroup Merge branch 'akpm' (patches from Andrew) 2021-11-06 14:08:17 -07:00
configs
debug kdb: Adopt scheduler's task classification 2021-11-03 17:21:37 +00:00
dma dma-mapping updates for Linux 5.16 2021-11-09 10:56:41 -08:00
entry Merge branch 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-11-10 16:15:54 -08:00
events Core: 2021-11-02 06:20:58 -07:00
futex
gcov
irq pci-v5.16-changes 2021-11-06 14:36:12 -07:00
kcsan
livepatch Tracing updates for 5.16: 2021-11-01 20:05:19 -07:00
locking Merge branch 'akpm' (patches from Andrew) 2021-11-09 10:11:53 -08:00
power Power management updates for 5.16-rc1 2021-11-02 16:04:28 -07:00
printk Merge branch 'akpm' (patches from Andrew) 2021-11-06 14:08:17 -07:00
rcu RCU pull request for v5.16 2021-11-01 20:25:38 -07:00
sched kernel.sys.v5.16 2021-11-10 16:10:47 -08:00
time
trace Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-11-15 08:49:23 -08:00
.gitignore
acct.c
async.c
audit_fsnotify.c
audit_tree.c audit/stable-5.16 PR 20211101 2021-11-01 21:17:39 -07:00
audit_watch.c \n 2021-11-06 16:43:20 -07:00
audit.c
audit.h audit/stable-5.16 PR 20211101 2021-11-01 21:17:39 -07:00
auditfilter.c
auditsc.c audit/stable-5.16 PR 20211101 2021-11-01 21:17:39 -07:00
backtracetest.c
bounds.c
capability.c
cfi.c
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c
crash_core.c
crash_dump.c
cred.c
delayacct.c
dma.c
exec_domain.c
exit.c Merge branch 'per_signal_struct_coredumps-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-11-03 12:15:29 -07:00
extable.c extable: use is_kernel_text() helper 2021-11-09 10:02:51 -08:00
fail_function.c
fork.c Merge branch 'akpm' (patches from Andrew) 2021-11-09 10:11:53 -08:00
freezer.c
gen_kheaders.sh
groups.c
hung_task.c
iomem.c
irq_work.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: replace local_irq_save() with a local_lock_t 2021-11-09 10:02:52 -08:00
kexec_core.c
kexec_elf.c
kexec_file.c memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED 2021-11-06 13:30:42 -07:00
kexec_internal.h
kexec.c
kheaders.c
kmod.c
kprobes.c Tracing updates for 5.16: 2021-11-01 20:05:19 -07:00
ksysfs.c
kthread.c Merge branch 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-11-10 16:15:54 -08:00
latencytop.c
Makefile Tracing updates for 5.16: 2021-11-01 20:05:19 -07:00
module_signature.c
module_signing.c
module-internal.h
module.c module: change to print useful messages from elf_validity_check() 2021-11-05 15:13:10 -07:00
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid_namespace.c
pid.c
profile.c
ptrace.c
range.c
reboot.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2021-11-12 11:53:16 -08:00
regset.c
relay.c
resource_kunit.c
resource.c kernel/resource: disallow access to exclusive system RAM regions 2021-11-09 10:02:52 -08:00
rseq.c
scftorture.c
scs.c
seccomp.c
signal.c Merge branch 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-11-10 16:15:54 -08:00
smp.c
smpboot.c
smpboot.h
softirq.c
stackleak.c
stacktrace.c stacktrace: move filter_irq_stacks() to kernel/stacktrace.c 2021-11-06 13:30:43 -07:00
static_call.c
stop_machine.c
sys_ni.c
sys.c
sysctl-test.c
sysctl.c
task_work.c
taskstats.c
torture.c
tracepoint.c
tsacct.c mm/mmap.c: fix a data race of mm->total_vm 2021-11-06 13:30:35 -07:00
ucount.c
uid16.c
uid16.h
umh.c
up.c
user_namespace.c
user-return-notifier.c
user.c
usermode_driver.c
utsname_sysctl.c
utsname.c
watch_queue.c
watchdog_hld.c
watchdog.c
workqueue_internal.h
workqueue.c Merge branch 'akpm' (patches from Andrew) 2021-11-06 14:08:17 -07:00