Merge branch 'bpf_line_info'

Martin Lau says:

====================
This patch series introduces the bpf_line_info.  Please see individual patch
for details.

It will be useful for introspection purpose, like:

[root@arch-fb-vm1 bpf]# ~/devshare/fb-kernel/linux/tools/bpf/bpftool/bpftool prog dump jited pinned /sys/fs/bpf/test_btf_haskv
[...]
int test_long_fname_2(struct dummy_tracepoint_args * arg):
bpf_prog_44a040bf25481309_test_long_fname_2:
; static int test_long_fname_2(struct dummy_tracepoint_args *arg)
   0:   push   %rbp
   1:   mov    %rsp,%rbp
   4:   sub    $0x30,%rsp
   b:   sub    $0x28,%rbp
   f:   mov    %rbx,0x0(%rbp)
  13:   mov    %r13,0x8(%rbp)
  17:   mov    %r14,0x10(%rbp)
  1b:   mov    %r15,0x18(%rbp)
  1f:   xor    %eax,%eax
  21:   mov    %rax,0x20(%rbp)
  25:   xor    %esi,%esi
; int key = 0;
  27:   mov    %esi,-0x4(%rbp)
; if (!arg->sock)
  2a:   mov    0x8(%rdi),%rdi
; if (!arg->sock)
  2e:   cmp    $0x0,%rdi
  32:   je     0x0000000000000070
  34:   mov    %rbp,%rsi
; counts = bpf_map_lookup_elem(&btf_map, &key);
  37:   add    $0xfffffffffffffffc,%rsi
  3b:   movabs $0xffff8881139d7480,%rdi
  45:   add    $0x110,%rdi
  4c:   mov    0x0(%rsi),%eax
  4f:   cmp    $0x4,%rax
  53:   jae    0x000000000000005e
  55:   shl    $0x3,%rax
  59:   add    %rdi,%rax
  5c:   jmp    0x0000000000000060
  5e:   xor    %eax,%eax
; if (!counts)
  60:   cmp    $0x0,%rax
  64:   je     0x0000000000000070
; counts->v6++;
  66:   mov    0x4(%rax),%edi
  69:   add    $0x1,%rdi
  6d:   mov    %edi,0x4(%rax)
  70:   mov    0x0(%rbp),%rbx
  74:   mov    0x8(%rbp),%r13
  78:   mov    0x10(%rbp),%r14
  7c:   mov    0x18(%rbp),%r15
  80:   add    $0x28,%rbp
  84:   leaveq
  85:   retq
[...]
====================

Signed-off-by: Alexei Starovoitov <[email protected]>

5 files changed, 49 insertions, 0 deletions

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index e82b7039fc66..0c992b86eb2c 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -319,7 +319,28 @@ struct bpf_prog_aux {
 	struct bpf_prog_offload *offload;
 	struct btf *btf;
 	struct bpf_func_info *func_info;
+	/* bpf_line_info loaded from userspace.  linfo->insn_off
+	 * has the xlated insn offset.
+	 * Both the main and sub prog share the same linfo.
+	 * The subprog can access its first linfo by
+	 * using the linfo_idx.
+	 */
+	struct bpf_line_info *linfo;
+	/* jited_linfo is the jited addr of the linfo.  It has a
+	 * one to one mapping to linfo:
+	 * jited_linfo[i] is the jited addr for the linfo[i]->insn_off.
+	 * Both the main and sub prog share the same jited_linfo.
+	 * The subprog can access its first jited_linfo by
+	 * using the linfo_idx.
+	 */
+	void **jited_linfo;
 	u32 func_info_cnt;
+	u32 nr_linfo;
+	/* subprog can use linfo_idx to access its first linfo and
+	 * jited_linfo.
+	 * main prog always has linfo_idx == 0
+	 */
+	u32 linfo_idx;
 	union {
 		struct work_struct work;
 		struct rcu_head	rcu;
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 11f5df1092d9..c736945be7c5 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -203,6 +203,7 @@ static inline bool bpf_verifier_log_needed(const struct bpf_verifier_log *log)
 
 struct bpf_subprog_info {
 	u32 start; /* insn idx of function entry point */
+	u32 linfo_idx; /* The idx to the main_prog->aux->linfo */
 	u16 stack_depth; /* max. stack depth used by this function */
 };
 
diff --git a/include/linux/btf.h b/include/linux/btf.h
index 8c2199b5d250..b98405a56383 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -46,6 +46,7 @@ void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
 		       struct seq_file *m);
 int btf_get_fd_by_id(u32 id);
 u32 btf_id(const struct btf *btf);
+bool btf_name_offset_valid(const struct btf *btf, u32 offset);
 
 #ifdef CONFIG_BPF_SYSCALL
 const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
diff --git a/include/linux/filter.h b/include/linux/filter.h
index d16deead65c6..29f21f9d7f68 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -718,6 +718,13 @@ void bpf_prog_free(struct bpf_prog *fp);
 
 bool bpf_opcode_in_insntable(u8 code);
 
+void bpf_prog_free_linfo(struct bpf_prog *prog);
+void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
+			       const u32 *insn_to_jit_off);
+int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog);
+void bpf_prog_free_jited_linfo(struct bpf_prog *prog);
+void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog);
+
 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 				  gfp_t gfp_extra_flags);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index a84fd232d934..7a66db8d15d5 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -356,6 +356,9 @@ union bpf_attr {
 		__u32		func_info_rec_size;	/* userspace bpf_func_info size */
 		__aligned_u64	func_info;	/* func info */
 		__u32		func_info_cnt;	/* number of bpf_func_info records */
+		__u32		line_info_rec_size;	/* userspace bpf_line_info size */
+		__aligned_u64	line_info;	/* line info */
+		__u32		line_info_cnt;	/* number of bpf_line_info records */
 	};
 
 	struct { /* anonymous struct used by BPF_OBJ_* commands */
@@ -2679,6 +2682,12 @@ struct bpf_prog_info {
 	__u32 func_info_rec_size;
 	__aligned_u64 func_info;
 	__u32 func_info_cnt;
+	__u32 line_info_cnt;
+	__aligned_u64 line_info;
+	__aligned_u64 jited_line_info;
+	__u32 jited_line_info_cnt;
+	__u32 line_info_rec_size;
+	__u32 jited_line_info_rec_size;
 } __attribute__((aligned(8)));
 
 struct bpf_map_info {
@@ -2995,4 +3004,14 @@ struct bpf_func_info {
 	__u32	type_id;
 };
 
+#define BPF_LINE_INFO_LINE_NUM(line_col)	((line_col) >> 10)
+#define BPF_LINE_INFO_LINE_COL(line_col)	((line_col) & 0x3ff)
+
+struct bpf_line_info {
+	__u32	insn_off;
+	__u32	file_name_off;
+	__u32	line_off;
+	__u32	line_col;
+};
+
 #endif /* _UAPI__LINUX_BPF_H__ */