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authorAlexei Starovoitov <ast@fb.com>2016-02-17 19:58:58 -0800
committerDavid S. Miller <davem@davemloft.net>2016-02-20 00:21:44 -0500
commitd5a3b1f691865be576c2bffa708549b8cdccda19 (patch)
tree12f6009f168baee6889a0fde07d60ac3f5c12aac /kernel/bpf/verifier.c
parent568b329a02f75ed3aaae5eb2cca384cb9e09cb29 (diff)
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>
Diffstat (limited to 'kernel/bpf/verifier.c')
-rw-r--r--kernel/bpf/verifier.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d1d3e8f57de9..42ba4ccc020b 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -246,6 +246,7 @@ static const struct {
{BPF_MAP_TYPE_PROG_ARRAY, BPF_FUNC_tail_call},
{BPF_MAP_TYPE_PERF_EVENT_ARRAY, BPF_FUNC_perf_event_read},
{BPF_MAP_TYPE_PERF_EVENT_ARRAY, BPF_FUNC_perf_event_output},
+ {BPF_MAP_TYPE_STACK_TRACE, BPF_FUNC_get_stackid},
};
static void print_verifier_state(struct verifier_env *env)
@@ -911,8 +912,11 @@ static int check_map_func_compatibility(struct bpf_map *map, int func_id)
* don't allow any other map type to be passed into
* the special func;
*/
- if (bool_func && bool_map != bool_func)
+ if (bool_func && bool_map != bool_func) {
+ verbose("cannot pass map_type %d into func %d\n",
+ map->map_type, func_id);
return -EINVAL;
+ }
}
return 0;