diff options
author | Yonghong Song <yhs@fb.com> | 2018-04-29 08:28:12 +0300 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2018-04-29 18:45:53 +0300 |
commit | de2ff05f48afcde816ff4edb217417f62f624ab5 (patch) | |
tree | d67117e42ddcdc0da2e91ea8949bc489f0553cef /tools | |
parent | 9cbe1f5a32dcd6d0508326f7d9098e5bc380a4fe (diff) | |
download | linux-de2ff05f48afcde816ff4edb217417f62f624ab5.tar.xz |
tools/bpf: add bpf_get_stack helper to tools headers
The tools header file bpf.h is synced with kernel uapi bpf.h.
The new helper is also added to bpf_helpers.h.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
-rw-r--r-- | tools/include/uapi/linux/bpf.h | 42 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/bpf_helpers.h | 2 |
2 files changed, 42 insertions, 2 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index da77a9388947..1afb606a18b9 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1767,6 +1767,40 @@ union bpf_attr { * **CONFIG_XFRM** configuration option. * Return * 0 on success, or a negative error in case of failure. + * + * int bpf_get_stack(struct pt_regs *regs, void *buf, u32 size, u64 flags) + * Description + * Return a user or a kernel stack in bpf program provided buffer. + * To achieve this, the helper needs *ctx*, which is a pointer + * to the context on which the tracing program is executed. + * To store the stacktrace, the bpf program provides *buf* with + * a nonnegative *size*. + * + * The last argument, *flags*, holds the number of stack frames to + * skip (from 0 to 255), masked with + * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set + * the following flags: + * + * **BPF_F_USER_STACK** + * Collect a user space stack instead of a kernel stack. + * **BPF_F_USER_BUILD_ID** + * Collect buildid+offset instead of ips for user stack, + * only valid if **BPF_F_USER_STACK** is also specified. + * + * **bpf_get_stack**\ () can collect up to + * **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject + * to sufficient large buffer size. Note that + * this limit can be controlled with the **sysctl** program, and + * that it should be manually increased in order to profile long + * user stacks (such as stacks for Java programs). To do so, use: + * + * :: + * + * # sysctl kernel.perf_event_max_stack=<new value> + * + * Return + * a non-negative value equal to or less than size on success, or + * a negative error in case of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -1835,7 +1869,8 @@ union bpf_attr { FN(msg_pull_data), \ FN(bind), \ FN(xdp_adjust_tail), \ - FN(skb_get_xfrm_state), + FN(skb_get_xfrm_state), \ + FN(get_stack), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -1869,11 +1904,14 @@ enum bpf_func_id { /* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */ #define BPF_F_TUNINFO_IPV6 (1ULL << 0) -/* BPF_FUNC_get_stackid flags. */ +/* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */ #define BPF_F_SKIP_FIELD_MASK 0xffULL #define BPF_F_USER_STACK (1ULL << 8) +/* flags used by BPF_FUNC_get_stackid only. */ #define BPF_F_FAST_STACK_CMP (1ULL << 9) #define BPF_F_REUSE_STACKID (1ULL << 10) +/* flags used by BPF_FUNC_get_stack only. */ +#define BPF_F_USER_BUILD_ID (1ULL << 11) /* BPF_FUNC_skb_set_tunnel_key flags. */ #define BPF_F_ZERO_CSUM_TX (1ULL << 1) diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index 69d7b918e66a..265f8e0e8ada 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -101,6 +101,8 @@ static int (*bpf_xdp_adjust_tail)(void *ctx, int offset) = static int (*bpf_skb_get_xfrm_state)(void *ctx, int index, void *state, int size, int flags) = (void *) BPF_FUNC_skb_get_xfrm_state; +static int (*bpf_get_stack)(void *ctx, void *buf, int size, int flags) = + (void *) BPF_FUNC_get_stack; /* llvm builtin functions that eBPF C program may use to * emit BPF_LD_ABS and BPF_LD_IND instructions |