Alexei Starovoitov
1fa0da8167
BACKPORT: bpf: Add support for BTF pointers to x86 JIT ...
Pointer to BTF object is a pointer to kernel object or NULL.
Such pointers can only be used by BPF_LDX instructions.
The verifier changed their opcode from LDX|MEM|size
to LDX|PROBE_MEM|size to make JITing easier.
The number of entries in extable is the number of BPF_LDX insns
that access kernel memory via "pointer to BTF type".
Only these load instructions can fault.
Since x86 extable is relative it has to be allocated in the same
memory region as JITed code.
Allocate it prior to last pass of JITing and let the last pass populate it.
Pointer to extable in bpf_prog_aux is necessary to make page fault
handling fast.
Page fault handling is done in two steps:
1. bpf_prog_kallsyms_find() finds BPF program that page faulted.
It's done by walking rb tree.
2. then extable for given bpf program is binary searched.
This process is similar to how page faulting is done for kernel modules.
The exception handler skips over faulting x86 instruction and
initializes destination register with zero. This mimics exact
behavior of bpf_probe_read (when probe_kernel_read faults dest is zeroed).
JITs for other architectures can add support in similar way.
Until then they will reject unknown opcode and fallback to interpreter.
Since extable should be aligned and placed near JITed code
make bpf_jit_binary_alloc() return 4 byte aligned image offset,
so that extable aligning formula in bpf_int_jit_compile() doesn't need
to rely on internal implementation of bpf_jit_binary_alloc().
On x86 gcc defaults to 16-byte alignment for regular kernel functions
due to better performance. JITed code may be aligned to 16 in the future,
but it will use 4 in the meantime.
Change-Id: I7b16ea50910e1044fbb097301292947debe81ef6
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191016032505.2089704-10-ast@kernel.org
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
2026-05-15 17:58:58 +07:00
BACKPORT: bpf: Add support for BTF pointers to x86 JIT
2026-05-15 17:58:58 +07:00
BACKPORT: treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 451
2026-05-15 17:57:56 +07:00
UPSTREAM: kdb: use correct pointer when 'btc' calls 'btt'
2022-02-21 16:30:05 +01:00
BACKPORT: perf, bpf: Introduce PERF_RECORD_BPF_EVENT
2026-05-15 17:58:54 +07:00
Merge branch 'android-4.9-q' of https://android.googlesource.com/kernel/common into lineage-20
2023-01-19 15:42:12 +01:00
Merge remote-tracking branch 'common/android-4.9-q' into android12-4.9-sdm845
2022-07-18 14:05:31 +03:00
UPSTREAM: locking/lockdep: Add new check to lock_downgrade()
2026-05-15 17:57:11 +07:00
treewide: Backport new vmalloc for large performance benefits
2026-05-15 17:48:25 +07:00
Merge remote-tracking branch 'common/android-4.9-q' into android12-4.9-sdm845
2022-06-12 01:39:01 +03:00
rcu: Fix self-wakeups for grace-period kthread
2026-05-15 17:49:36 +07:00
UPSTREAM: bpf: check that BPF programs run with preemption disabled
2026-05-15 17:57:32 +07:00
UPSTREAM: time: add get_timespec64 and put_timespec64
2026-05-15 17:58:00 +07:00
UPSTREAM: bpf: Implement accurate raw_tp context access via BTF
2026-05-15 17:58:56 +07:00
BACKPORT: Provide in-kernel headers to make extending kernel easier
2019-07-03 14:30:53 -04:00
acct: fix potential integer overflow in encode_comp_t()
2023-01-07 12:07:31 +01:00
Merge branch 'android-4.9-q' of https://android.googlesource.com/kernel/common into lineage-18.1-caf-sdm845
2021-04-26 01:27:02 +03:00
audit: fix a net reference leak in audit_list_rules_send()
2021-04-07 12:05:41 +02:00
audit: CONFIG_CHANGE don't log internal bookkeeping as an event
2020-10-01 20:40:07 +02:00
audit: fix a net reference leak in audit_list_rules_send()
2021-04-07 12:05:41 +02:00
Merge android-4.9.204(72e8598) into msm-4.9
2020-01-06 18:13:26 +08:00
UPSTREAM: time: add get_timespec64 and put_timespec64
2026-05-15 17:58:00 +07:00
rcu: Migrate callbacks earlier in the CPU-offline timeline
2026-05-15 17:49:31 +07:00
Merge branch 'android-4.9-q' of https://android.googlesource.com/kernel/common into HEAD
2020-06-30 02:33:58 +03:00
memcg: account security cred as well to kmemcg
2020-01-12 11:24:13 +01:00
BACKPORT: umh: add exit routine for UMH process
2026-05-15 17:58:52 +07:00
BACKPORT: bpf: Add support for BTF pointers to x86 JIT
2026-05-15 17:58:58 +07:00
UPSTREAM: perf: Add PERF_RECORD_NAMESPACES to include namespaces related info
2026-05-15 17:58:54 +07:00
mm, futex: fix shared futex pgoff on shmem huge page
2021-07-11 12:46:40 +02:00
BACKPORT: kheaders: Do not regenerate archive if config is not changed
2019-07-03 14:31:16 -04:00
treewide: Backport new vmalloc for large performance benefits
2026-05-15 17:48:25 +07:00
Merge android-4.9.170 ( 1ef64da) into msm-4.9
2019-05-30 14:15:13 +08:00
jump_label: Disable jump labels in __exit code
2021-06-06 18:42:18 +03:00
BACKPORT: symbol lookup: introduce dereference_symbol_descriptor()
2026-05-15 17:57:02 +07:00
BACKPORT: bpf: introduce bpf_spin_lock
2026-05-15 17:57:29 +07:00
BACKPORT: mm: split page_type out from _mapcount
2026-05-15 17:57:58 +07:00
Merge remote-tracking branch 'common/android-4.9-q' into android12-4.9-sdm845
2022-07-18 14:05:31 +03:00
BACKPORT: kheaders: Move from proc to sysfs
2019-07-03 14:31:02 -04:00
BACKPORT: kmod: split out umh code into its own file
2026-05-15 17:56:31 +07:00
UPSTREAM: kprobes: Show blacklist addresses as same as kallsyms does
2026-05-15 17:57:02 +07:00
Merge branch 'android-4.9-q' of https://android.googlesource.com/kernel/common into lineage-18.1-caf-sdm845
2021-07-22 02:11:11 +03:00
BACKPORT: kmod: split out umh code into its own file
2026-05-15 17:56:31 +07:00
BACKPORT: bpf: support raw tracepoints in modules
2026-05-15 17:57:25 +07:00
x86/mm: split vmalloc_sync_all()
2020-04-02 17:20:26 +02:00
UPSTREAM: perf: Add PERF_RECORD_NAMESPACES to include namespaces related info
2026-05-15 17:58:54 +07:00
padata: purge get_cpu and reorder_via_wq from padata_do_serial
2020-05-27 16:41:53 +02:00
BACKPORT: locking/refcount: Create unchecked atomic_t implementation
2026-05-15 17:54:59 +07:00
UPSTREAM: locking/atomic, kref: Add KREF_INIT()
2021-01-05 16:00:48 +00:00
memcg: enable accounting for pids in nested pid namespaces
2021-09-22 11:43:08 +02:00
profiling: fix shift-out-of-bounds bugs
2021-09-26 13:36:18 +02:00
ptrace: Reimplement PTRACE_KILL by always sending SIGKILL
2022-06-14 16:52:28 +02:00
reboot: fix overflow parsing reboot cpu number
2020-11-18 18:26:32 +01:00
kernel/relay.c: fix memleak on destroy relay channel
2020-08-26 10:29:03 +02:00
UPSTREAM: seccomp, bpf: disable preemption before calling into bpf prog
2026-05-15 17:58:54 +07:00
BACKPORT: cgroup: freezer: call cgroup_enter_frozen() with preemption disabled in ptrace_stop()
2026-05-15 17:50:47 +07:00
Merge remote-tracking branch 'common/android-4.9-q' into android12-4.9-sdm845
2022-06-12 01:39:01 +03:00
syscall: Increase bpf fake uname to 5.4.186
2026-05-15 17:58:55 +07:00
BACKPORT: signal: support CLONE_PIDFD with pidfd_send_signal
2019-09-03 13:44:59 -07:00
BACKPORT: sysctl: define proc_do_static_key()
2026-05-15 17:57:55 +07:00
taskstats: fix data-race
2020-01-12 11:24:12 +01:00
BACKPORT: tracepoint: Add tracepoint_probe_register_may_exist() for BPF tracing
2026-05-15 17:57:41 +07:00
taskstats: Cleanup the use of task->exit_code
2022-02-23 11:56:40 +01:00
BACKPORT: umh: add exit routine for UMH process
2026-05-15 17:58:52 +07:00
rcu: Create RCU-specific workqueues with rescuers
2026-05-15 17:49:31 +07:00
1fa0da8167