On 7/9/22 8:44 AM, Yafang Shao wrote:
The raw tracepoint may cause unexpected memory allocation if we set
BPF_F_NO_PREALLOC. So let's warn on it.
Please extend raw_tracepoint to other attach types which
may cause runtime map allocations.
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
---
kernel/bpf/verifier.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index e3cf6194c24f..3cd8260827e0 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -12574,14 +12574,20 @@ static int check_map_prealloc(struct bpf_map *map)
!(map->map_flags & BPF_F_NO_PREALLOC);
}
-static bool is_tracing_prog_type(enum bpf_prog_type type)
+static bool is_tracing_prog_type(enum bpf_prog_type prog_type,
+ enum bpf_attach_type attach_type)
{
- switch (type) {
+ switch (prog_type) {
case BPF_PROG_TYPE_KPROBE:
case BPF_PROG_TYPE_TRACEPOINT:
case BPF_PROG_TYPE_PERF_EVENT:
case BPF_PROG_TYPE_RAW_TRACEPOINT:
+ case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
return true;
+ case BPF_PROG_TYPE_TRACING:
+ if (attach_type == BPF_TRACE_RAW_TP)
+ return true;
As Alexei mentioned earlier, here we should have
if (attach_type != BPF_TRACE_ITER)
return true;
For attach types with BPF_PROG_TYPE_TRACING programs,
BPF_TRACE_ITER attach type can only appear in process context.
All other attach types may appear in non-process context.
+ return false;
default:
return false;
}
@@ -12601,7 +12607,9 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
struct bpf_prog *prog)
{
+ enum bpf_attach_type attach_type = prog->expected_attach_type;
enum bpf_prog_type prog_type = resolve_prog_type(prog);
+
[...]
