[RFC PATCH v2 11/26] perf bpf: Store arbitrary entries instread fd array in bpf_program

[He Kuang]

The bpf progs loaded into kernel are represented by fd, but we need
new types for storing the entity of userspace bpf progs. This patch
uses a void pointer to make it more generic so we can store any new
types and cast back to its original type when used.

Signed-off-by: He Kuang <heku...@huawei.com>
Signed-off-by: Wang Nan <wangn...@huawei.com>
---
 tools/lib/bpf/libbpf.c | 41 +++++++++++++++++++++--------------------
 1 file changed, 21 insertions(+), 20 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 754e460..97f72b2 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -154,7 +154,7 @@ struct bpf_program {
 
        struct {
                int nr;
-               int *fds;
+               void *entries;
        } instances;
        bpf_program_prep_t preprocessor;
 
@@ -226,14 +226,14 @@ static void bpf_program__unload(struct bpf_program *prog)
         */
        if (prog->instances.nr > 0) {
                for (i = 0; i < prog->instances.nr; i++)
-                       zclose(prog->instances.fds[i]);
+                       zclose(((int *)prog->instances.entries)[i]);
        } else if (prog->instances.nr != -1) {
                pr_warning("Internal error: instances.nr is %d\n",
                           prog->instances.nr);
        }
 
        prog->instances.nr = -1;
-       zfree(&prog->instances.fds);
+       zfree(&prog->instances.entries);
 }
 
 static void bpf_program__exit(struct bpf_program *prog)
@@ -284,7 +284,7 @@ bpf_program__init(void *data, size_t size, char *name, int 
idx,
        memcpy(prog->insns, data,
               prog->insns_cnt * sizeof(struct bpf_insn));
        prog->idx = idx;
-       prog->instances.fds = NULL;
+       prog->instances.entries = NULL;
        prog->instances.nr = -1;
 
        return 0;
@@ -934,20 +934,21 @@ bpf_program__load(struct bpf_program *prog,
 {
        int err = 0, fd, i;
 
-       if (prog->instances.nr < 0 || !prog->instances.fds) {
+       if (prog->instances.nr < 0 || !prog->instances.entries) {
                if (prog->preprocessor) {
                        pr_warning("Internal error: can't load program '%s'\n",
                                   prog->section_name);
                        return -LIBBPF_ERRNO__INTERNAL;
                }
 
-               prog->instances.fds = malloc(sizeof(int));
-               if (!prog->instances.fds) {
-                       pr_warning("Not enough memory for BPF fds\n");
+               prog->instances.entries = malloc(sizeof(int));
+               if (!prog->instances.entries) {
+                       pr_warning("Not enough memory for BPF entries\n");
                        return -ENOMEM;
                }
+
                prog->instances.nr = 1;
-               prog->instances.fds[0] = -1;
+               ((int *)prog->instances.entries)[0] = -1;
        }
 
        if (!prog->preprocessor) {
@@ -958,7 +959,7 @@ bpf_program__load(struct bpf_program *prog,
                err = load_program(prog->insns, prog->insns_cnt,
                                   license, kern_version, &fd);
                if (!err)
-                       prog->instances.fds[0] = fd;
+                       ((int *)prog->instances.entries)[0] = fd;
                goto out;
        }
 
@@ -978,7 +979,7 @@ bpf_program__load(struct bpf_program *prog,
                if (!result.new_insn_ptr || !result.new_insn_cnt) {
                        pr_debug("Skip loading the %dth instance of program 
'%s'\n",
                                 i, prog->section_name);
-                       prog->instances.fds[i] = -1;
+                       ((int *)prog->instances.entries)[i] = -1;
                        continue;
                }
 
@@ -992,7 +993,7 @@ bpf_program__load(struct bpf_program *prog,
                        goto out;
                }
 
-               prog->instances.fds[i] = fd;
+               ((int *)prog->instances.entries)[i] = fd;
        }
 out:
        if (err)
@@ -1254,27 +1255,27 @@ int bpf_program__fd(struct bpf_program *prog)
 int bpf_program__set_prep(struct bpf_program *prog, int nr_instances,
                          bpf_program_prep_t prep)
 {
-       int *instances_fds;
+       int *instances_entries;
 
        if (nr_instances <= 0 || !prep)
                return -EINVAL;
 
-       if (prog->instances.nr > 0 || prog->instances.fds) {
+       if (prog->instances.nr > 0 || prog->instances.entries) {
                pr_warning("Can't set pre-processor after loading\n");
                return -EINVAL;
        }
 
-       instances_fds = malloc(sizeof(int) * nr_instances);
-       if (!instances_fds) {
-               pr_warning("alloc memory failed for fds\n");
+       instances_entries = malloc(sizeof(int) * nr_instances);
+       if (!instances_entries) {
+               pr_warning("alloc memory failed for entries\n");
                return -ENOMEM;
        }
 
        /* fill all fd with -1 */
-       memset(instances_fds, -1, sizeof(int) * nr_instances);
+       memset(instances_entries, -1, sizeof(int) * nr_instances);
 
        prog->instances.nr = nr_instances;
-       prog->instances.fds = instances_fds;
+       prog->instances.entries = instances_entries;
        prog->preprocessor = prep;
        return 0;
 }
@@ -1289,7 +1290,7 @@ int bpf_program__nth_fd(struct bpf_program *prog, int n)
                return -EINVAL;
        }
 
-       fd = prog->instances.fds[n];
+       fd = ((int *)prog->instances.entries)[n];
        if (fd < 0) {
                pr_warning("%dth instance of program '%s' is invalid\n",
                           n, prog->section_name);
-- 
1.8.5.2