diff options
Diffstat (limited to 'kernel/bpf/preload/bpf_preload_kern.c')
-rw-r--r-- | kernel/bpf/preload/bpf_preload_kern.c | 121 |
1 files changed, 61 insertions, 60 deletions
diff --git a/kernel/bpf/preload/bpf_preload_kern.c b/kernel/bpf/preload/bpf_preload_kern.c index 79c5772465f1..0c63bc2cd895 100644 --- a/kernel/bpf/preload/bpf_preload_kern.c +++ b/kernel/bpf/preload/bpf_preload_kern.c @@ -2,90 +2,91 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/init.h> #include <linux/module.h> -#include <linux/pid.h> -#include <linux/fs.h> -#include <linux/sched/signal.h> #include "bpf_preload.h" +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ +#include "iterators/iterators.lskel-little-endian.h" +#else +#include "iterators/iterators.lskel-big-endian.h" +#endif -extern char bpf_preload_umd_start; -extern char bpf_preload_umd_end; +static struct bpf_link *maps_link, *progs_link; +static struct iterators_bpf *skel; -static int preload(struct bpf_preload_info *obj); -static int finish(void); +static void free_links_and_skel(void) +{ + if (!IS_ERR_OR_NULL(maps_link)) + bpf_link_put(maps_link); + if (!IS_ERR_OR_NULL(progs_link)) + bpf_link_put(progs_link); + iterators_bpf__destroy(skel); +} + +static int preload(struct bpf_preload_info *obj) +{ + strscpy(obj[0].link_name, "maps.debug", sizeof(obj[0].link_name)); + obj[0].link = maps_link; + strscpy(obj[1].link_name, "progs.debug", sizeof(obj[1].link_name)); + obj[1].link = progs_link; + return 0; +} -static struct bpf_preload_ops umd_ops = { - .info.driver_name = "bpf_preload", +static struct bpf_preload_ops ops = { .preload = preload, - .finish = finish, .owner = THIS_MODULE, }; -static int preload(struct bpf_preload_info *obj) +static int load_skel(void) { - int magic = BPF_PRELOAD_START; - loff_t pos = 0; - int i, err; - ssize_t n; + int err; - err = fork_usermode_driver(&umd_ops.info); + skel = iterators_bpf__open(); + if (!skel) + return -ENOMEM; + err = iterators_bpf__load(skel); if (err) - return err; - - /* send the start magic to let UMD proceed with loading BPF progs */ - n = kernel_write(umd_ops.info.pipe_to_umh, - &magic, sizeof(magic), &pos); - if (n != sizeof(magic)) - return -EPIPE; - - /* receive bpf_link IDs and names from UMD */ - pos = 0; - for (i = 0; i < BPF_PRELOAD_LINKS; i++) { - n = kernel_read(umd_ops.info.pipe_from_umh, - &obj[i], sizeof(*obj), &pos); - if (n != sizeof(*obj)) - return -EPIPE; + goto out; + err = iterators_bpf__attach(skel); + if (err) + goto out; + maps_link = bpf_link_get_from_fd(skel->links.dump_bpf_map_fd); + if (IS_ERR(maps_link)) { + err = PTR_ERR(maps_link); + goto out; } + progs_link = bpf_link_get_from_fd(skel->links.dump_bpf_prog_fd); + if (IS_ERR(progs_link)) { + err = PTR_ERR(progs_link); + goto out; + } + /* Avoid taking over stdin/stdout/stderr of init process. Zeroing out + * makes skel_closenz() a no-op later in iterators_bpf__destroy(). + */ + close_fd(skel->links.dump_bpf_map_fd); + skel->links.dump_bpf_map_fd = 0; + close_fd(skel->links.dump_bpf_prog_fd); + skel->links.dump_bpf_prog_fd = 0; return 0; +out: + free_links_and_skel(); + return err; } -static int finish(void) -{ - int magic = BPF_PRELOAD_END; - struct pid *tgid; - loff_t pos = 0; - ssize_t n; - - /* send the last magic to UMD. It will do a normal exit. */ - n = kernel_write(umd_ops.info.pipe_to_umh, - &magic, sizeof(magic), &pos); - if (n != sizeof(magic)) - return -EPIPE; - tgid = umd_ops.info.tgid; - wait_event(tgid->wait_pidfd, thread_group_exited(tgid)); - umd_ops.info.tgid = NULL; - return 0; -} - -static int __init load_umd(void) +static int __init load(void) { int err; - err = umd_load_blob(&umd_ops.info, &bpf_preload_umd_start, - &bpf_preload_umd_end - &bpf_preload_umd_start); + err = load_skel(); if (err) return err; - bpf_preload_ops = &umd_ops; + bpf_preload_ops = &ops; return err; } -static void __exit fini_umd(void) +static void __exit fini(void) { bpf_preload_ops = NULL; - /* kill UMD in case it's still there due to earlier error */ - kill_pid(umd_ops.info.tgid, SIGKILL, 1); - umd_ops.info.tgid = NULL; - umd_unload_blob(&umd_ops.info); + free_links_and_skel(); } -late_initcall(load_umd); -module_exit(fini_umd); +late_initcall(load); +module_exit(fini); MODULE_LICENSE("GPL"); |