bpf: introduce BPF_MAP_TYPE_STACK_TRACE

add new map type to store stack traces and corresponding helper
bpf_get_stackid(ctx, map, flags) - walk user or kernel stack and return id
@ctx: struct pt_regs*
@map: pointer to stack_trace map
@flags: bits 0-7 - numer of stack frames to skip
        bit 8 - collect user stack instead of kernel
        bit 9 - compare stacks by hash only
        bit 10 - if two different stacks hash into the same stackid
                 discard old
        other bits - reserved
Return: >= 0 stackid on success or negative error

stackid is a 32-bit integer handle that can be further combined with
other data (including other stackid) and used as a key into maps.

Userspace will access stackmap using standard lookup/delete syscall commands to
retrieve full stack trace for given stackid.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexei Starovoitov
2016-02-17 19:58:58 -08:00
committed by David S. Miller
parent 568b329a02
commit d5a3b1f691
6 changed files with 269 additions and 1 deletions

View File

@@ -237,6 +237,7 @@ extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
extern const struct bpf_func_proto bpf_get_current_comm_proto;
extern const struct bpf_func_proto bpf_skb_vlan_push_proto;
extern const struct bpf_func_proto bpf_skb_vlan_pop_proto;
extern const struct bpf_func_proto bpf_get_stackid_proto;
/* Shared helpers among cBPF and eBPF. */
void bpf_user_rnd_init_once(void);