Re: [PATCH 5/5] bpf: Allow to resolve bpf trampoline in unwind
From: Alexei Starovoitov <hidden>
Date: 2020-01-06 23:46:44
Also in:
bpf
On Sun, Dec 29, 2019 at 03:37:40PM +0100, Jiri Olsa wrote:
When unwinding the stack we need to identify each address to successfully continue. Adding latch tree to keep trampolines for quick lookup during the unwind. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
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quoted hunk ↗ jump to hunk
+bool is_bpf_trampoline(void *addr) +{ + return latch_tree_find(addr, &tree, &tree_ops) != NULL; +} + struct bpf_trampoline *bpf_trampoline_lookup(u64 key) { struct bpf_trampoline *tr;@@ -65,6 +98,7 @@ struct bpf_trampoline *bpf_trampoline_lookup(u64 key) for (i = 0; i < BPF_TRAMP_MAX; i++) INIT_HLIST_HEAD(&tr->progs_hlist[i]); tr->image = image; + latch_tree_insert(&tr->tnode, &tree, &tree_ops);
Thanks for the fix. I was thinking to apply it, but then realized that bpf dispatcher logic has the same issue. Could you generalize the fix for both? May be bpf_jit_alloc_exec_page() can do latch_tree_insert() ? and new version of bpf_jit_free_exec() is needed that will do latch_tree_erase(). Wdyt?