github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-27 17:47:41 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

bpf: Verifier support for sleepable tracepoint programs

Browse Source 
Allow BPF_PROG_TYPE_RAW_TRACEPOINT, BPF_PROG_TYPE_TRACEPOINT, and
BPF_TRACE_RAW_TP (tp_btf) programs to be sleepable by adding them
to can_be_sleepable().

For BTF-based raw tracepoints (tp_btf), add a load-time check in
bpf_check_attach_target() that rejects sleepable programs attaching
to non-faultable tracepoints with a descriptive error message.

For raw tracepoints (raw_tp), add an attach-time check in
bpf_raw_tp_link_attach() that rejects sleepable programs on
non-faultable tracepoints. The attach-time check is needed because
the tracepoint name is not known at load time for raw_tp.

The attach-time check for classic tracepoints (tp) in
__perf_event_set_bpf_prog() was added in the previous patch.

Replace the verbose error message that enumerates allowed program
types with a generic "Program of this type cannot be sleepable"
message, since the list of sleepable-capable types keeps growing.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20260422-sleepable_tracepoints-v13-4-99005dff21ef@meta.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
This commit is contained in:
Mykyta Yatsenko 2026-04-22 12:41:09 -07:00 committed by Kumar Kartikeya Dwivedi
parent 57918341dd
commit 8cfb77d309
No known key found for this signature in database
GPG Key ID: 472D377B63542F83
2 changed files with 16 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
kernel/bpf/syscall.c
View File

@ -4281,6 +4281,11 @@ static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
if (!btp)
return -ENOENT;
if (prog->sleepable && !tracepoint_is_faultable(btp->tp)) {
bpf_put_raw_tracepoint(btp);
return -EINVAL;
}
link = kzalloc_obj(*link, GFP_USER);
if (!link) {
err = -ENOMEM;

13
kernel/bpf/verifier.c
View File

@ -19267,6 +19267,12 @@ int bpf_check_attach_target(struct bpf_verifier_log *log,
btp = bpf_get_raw_tracepoint(tname);
if (!btp)
return -EINVAL;
if (prog->sleepable && !tracepoint_is_faultable(btp->tp)) {
bpf_log(log, "Sleepable program cannot attach to non-faultable tracepoint %s\n",
tname);
bpf_put_raw_tracepoint(btp);
return -EINVAL;
}
fname = kallsyms_lookup((unsigned long)btp->bpf_func, NULL, NULL, NULL,
trace_symbol);
bpf_put_raw_tracepoint(btp);
@ -19483,6 +19489,7 @@ static bool can_be_sleepable(struct bpf_prog *prog)
case BPF_MODIFY_RETURN:
case BPF_TRACE_ITER:
case BPF_TRACE_FSESSION:
case BPF_TRACE_RAW_TP:
return true;
default:
return false;
@ -19490,7 +19497,9 @@ static bool can_be_sleepable(struct bpf_prog *prog)
}
return prog->type == BPF_PROG_TYPE_LSM ||
prog->type == BPF_PROG_TYPE_KPROBE /* only for uprobes */ ||
prog->type == BPF_PROG_TYPE_STRUCT_OPS;
prog->type == BPF_PROG_TYPE_STRUCT_OPS ||
prog->type == BPF_PROG_TYPE_RAW_TRACEPOINT ||
prog->type == BPF_PROG_TYPE_TRACEPOINT;
}
static int check_attach_btf_id(struct bpf_verifier_env *env)
@ -19512,7 +19521,7 @@ static int check_attach_btf_id(struct bpf_verifier_env *env)
}
if (prog->sleepable && !can_be_sleepable(prog)) {
verbose(env, "Only fentry/fexit/fsession/fmod_ret, lsm, iter, uprobe, and struct_ops programs can be sleepable\n");
verbose(env, "Program of this type cannot be sleepable\n");
return -EINVAL;
}