diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 6f094c9f7f0b..02d7014417a0 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -7226,6 +7226,7 @@ int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, { bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL; struct bpf_core_cand_list cands = {}; + struct bpf_core_relo_res targ_res; struct bpf_core_spec *specs; int err; @@ -7265,13 +7266,19 @@ int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, cands.len = cc->cnt; /* cand_cache_mutex needs to span the cache lookup and * copy of btf pointer into bpf_core_cand_list, - * since module can be unloaded while bpf_core_apply_relo_insn + * since module can be unloaded while bpf_core_calc_relo_insn * is working with module's btf. */ } - err = bpf_core_apply_relo_insn((void *)ctx->log, insn, relo->insn_off / 8, - relo, relo_idx, ctx->btf, &cands, specs); + err = bpf_core_calc_relo_insn((void *)ctx->log, relo, relo_idx, ctx->btf, &cands, specs, + &targ_res); + if (err) + goto out; + + err = bpf_core_patch_insn((void *)ctx->log, insn, relo->insn_off / 8, relo, relo_idx, + &targ_res); + out: kfree(specs); if (need_cands) { diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 42d96549a804..ebb0193d07f0 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -827,7 +827,7 @@ int bpf_jit_add_poke_descriptor(struct bpf_prog *prog, struct bpf_prog_pack { struct list_head list; void *ptr; - unsigned long bitmap[BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)]; + unsigned long bitmap[]; }; #define BPF_PROG_MAX_PACK_PROG_SIZE BPF_PROG_PACK_SIZE @@ -840,7 +840,7 @@ static struct bpf_prog_pack *alloc_new_pack(void) { struct bpf_prog_pack *pack; - pack = kzalloc(sizeof(*pack), GFP_KERNEL); + pack = kzalloc(sizeof(*pack) + BITS_TO_BYTES(BPF_PROG_CHUNK_COUNT), GFP_KERNEL); if (!pack) return NULL; pack->ptr = module_alloc(BPF_PROG_PACK_SIZE); @@ -1069,6 +1069,7 @@ bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr, *rw_header = kvmalloc(size, GFP_KERNEL); if (!*rw_header) { + bpf_arch_text_copy(&ro_header->size, &size, sizeof(size)); bpf_prog_pack_free(ro_header); bpf_jit_uncharge_modmem(size); return NULL; diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c index 5a8d9f7467bf..4f841e16779e 100644 --- a/kernel/bpf/inode.c +++ b/kernel/bpf/inode.c @@ -710,11 +710,10 @@ static DEFINE_MUTEX(bpf_preload_lock); static int populate_bpffs(struct dentry *parent) { struct bpf_preload_info objs[BPF_PRELOAD_LINKS] = {}; - struct bpf_link *links[BPF_PRELOAD_LINKS] = {}; int err = 0, i; /* grab the mutex to make sure the kernel interactions with bpf_preload - * UMD are serialized + * are serialized */ mutex_lock(&bpf_preload_lock); @@ -722,40 +721,22 @@ static int populate_bpffs(struct dentry *parent) if (!bpf_preload_mod_get()) goto out; - if (!bpf_preload_ops->info.tgid) { - /* preload() will start UMD that will load BPF iterator programs */ - err = bpf_preload_ops->preload(objs); - if (err) + err = bpf_preload_ops->preload(objs); + if (err) + goto out_put; + for (i = 0; i < BPF_PRELOAD_LINKS; i++) { + bpf_link_inc(objs[i].link); + err = bpf_iter_link_pin_kernel(parent, + objs[i].link_name, objs[i].link); + if (err) { + bpf_link_put(objs[i].link); goto out_put; - for (i = 0; i < BPF_PRELOAD_LINKS; i++) { - links[i] = bpf_link_by_id(objs[i].link_id); - if (IS_ERR(links[i])) { - err = PTR_ERR(links[i]); - goto out_put; - } } - for (i = 0; i < BPF_PRELOAD_LINKS; i++) { - err = bpf_iter_link_pin_kernel(parent, - objs[i].link_name, links[i]); - if (err) - goto out_put; - /* do not unlink successfully pinned links even - * if later link fails to pin - */ - links[i] = NULL; - } - /* finish() will tell UMD process to exit */ - err = bpf_preload_ops->finish(); - if (err) - goto out_put; } out_put: bpf_preload_mod_put(); out: mutex_unlock(&bpf_preload_lock); - for (i = 0; i < BPF_PRELOAD_LINKS && err; i++) - if (!IS_ERR_OR_NULL(links[i])) - bpf_link_put(links[i]); return err; } diff --git a/kernel/bpf/preload/Kconfig b/kernel/bpf/preload/Kconfig index 26bced262473..c9d45c9d6918 100644 --- a/kernel/bpf/preload/Kconfig +++ b/kernel/bpf/preload/Kconfig @@ -18,10 +18,9 @@ menuconfig BPF_PRELOAD if BPF_PRELOAD config BPF_PRELOAD_UMD - tristate "bpf_preload kernel module with user mode driver" - depends on CC_CAN_LINK - depends on m || CC_CAN_LINK_STATIC + tristate "bpf_preload kernel module" default m help - This builds bpf_preload kernel module with embedded user mode driver. + This builds bpf_preload kernel module with embedded BPF programs for + introspection in bpffs. endif diff --git a/kernel/bpf/preload/Makefile b/kernel/bpf/preload/Makefile index baf47d9c7557..167534e3b0b4 100644 --- a/kernel/bpf/preload/Makefile +++ b/kernel/bpf/preload/Makefile @@ -3,16 +3,6 @@ LIBBPF_SRCS = $(srctree)/tools/lib/bpf/ LIBBPF_INCLUDE = $(LIBBPF_SRCS)/.. -userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi \ - -I $(LIBBPF_INCLUDE) -Wno-unused-result - -userprogs := bpf_preload_umd - -bpf_preload_umd-objs := iterators/iterators.o - -$(obj)/bpf_preload_umd: - -$(obj)/bpf_preload_umd_blob.o: $(obj)/bpf_preload_umd - obj-$(CONFIG_BPF_PRELOAD_UMD) += bpf_preload.o -bpf_preload-objs += bpf_preload_kern.o bpf_preload_umd_blob.o +CFLAGS_bpf_preload_kern.o += -I $(LIBBPF_INCLUDE) +bpf_preload-objs += bpf_preload_kern.o diff --git a/kernel/bpf/preload/bpf_preload.h b/kernel/bpf/preload/bpf_preload.h index 2f9932276f2e..f065c91213a0 100644 --- a/kernel/bpf/preload/bpf_preload.h +++ b/kernel/bpf/preload/bpf_preload.h @@ -2,13 +2,13 @@ #ifndef _BPF_PRELOAD_H #define _BPF_PRELOAD_H -#include -#include "iterators/bpf_preload_common.h" +struct bpf_preload_info { + char link_name[16]; + struct bpf_link *link; +}; struct bpf_preload_ops { - struct umd_info info; int (*preload)(struct bpf_preload_info *); - int (*finish)(void); struct module *owner; }; extern struct bpf_preload_ops *bpf_preload_ops; diff --git a/kernel/bpf/preload/bpf_preload_kern.c b/kernel/bpf/preload/bpf_preload_kern.c index 53736e52c1df..30207c048d36 100644 --- a/kernel/bpf/preload/bpf_preload_kern.c +++ b/kernel/bpf/preload/bpf_preload_kern.c @@ -2,101 +2,80 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include -#include -#include -#include #include "bpf_preload.h" +#include "iterators/iterators.lskel.h" -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 struct bpf_preload_ops umd_ops = { - .info.driver_name = "bpf_preload", - .preload = preload, - .finish = finish, - .owner = THIS_MODULE, -}; +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) { - int magic = BPF_PRELOAD_START; - loff_t pos = 0; - int i, err; - ssize_t n; - - err = fork_usermode_driver(&umd_ops.info); - 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; - } + strlcpy(obj[0].link_name, "maps.debug", sizeof(obj[0].link_name)); + obj[0].link = maps_link; + strlcpy(obj[1].link_name, "progs.debug", sizeof(obj[1].link_name)); + obj[1].link = progs_link; return 0; } -static int finish(void) -{ - int magic = BPF_PRELOAD_END; - struct pid *tgid; - loff_t pos = 0; - ssize_t n; +static struct bpf_preload_ops ops = { + .preload = preload, + .owner = THIS_MODULE, +}; - /* 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; - if (tgid) { - wait_event(tgid->wait_pidfd, thread_group_exited(tgid)); - umd_cleanup_helper(&umd_ops.info); - } - return 0; -} - -static int __init load_umd(void) +static int load_skel(void) { int err; - err = umd_load_blob(&umd_ops.info, &bpf_preload_umd_start, - &bpf_preload_umd_end - &bpf_preload_umd_start); + skel = iterators_bpf__open(); + if (!skel) + return -ENOMEM; + err = iterators_bpf__load(skel); if (err) - return err; - bpf_preload_ops = &umd_ops; + 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; + } + return 0; +out: + free_links_and_skel(); return err; } -static void __exit fini_umd(void) +static int __init load(void) { - struct pid *tgid; + int err; - bpf_preload_ops = NULL; - - /* kill UMD in case it's still there due to earlier error */ - tgid = umd_ops.info.tgid; - if (tgid) { - kill_pid(tgid, SIGKILL, 1); - - wait_event(tgid->wait_pidfd, thread_group_exited(tgid)); - umd_cleanup_helper(&umd_ops.info); - } - umd_unload_blob(&umd_ops.info); + err = load_skel(); + if (err) + return err; + bpf_preload_ops = &ops; + return err; } -late_initcall(load_umd); -module_exit(fini_umd); + +static void __exit fini(void) +{ + bpf_preload_ops = NULL; + free_links_and_skel(); +} +late_initcall(load); +module_exit(fini); MODULE_LICENSE("GPL"); diff --git a/kernel/bpf/preload/bpf_preload_umd_blob.S b/kernel/bpf/preload/bpf_preload_umd_blob.S deleted file mode 100644 index f1f40223b5c3..000000000000 --- a/kernel/bpf/preload/bpf_preload_umd_blob.S +++ /dev/null @@ -1,7 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ - .section .init.rodata, "a" - .global bpf_preload_umd_start -bpf_preload_umd_start: - .incbin "kernel/bpf/preload/bpf_preload_umd" - .global bpf_preload_umd_end -bpf_preload_umd_end: diff --git a/kernel/bpf/preload/iterators/bpf_preload_common.h b/kernel/bpf/preload/iterators/bpf_preload_common.h deleted file mode 100644 index 8464d1a48c05..000000000000 --- a/kernel/bpf/preload/iterators/bpf_preload_common.h +++ /dev/null @@ -1,13 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _BPF_PRELOAD_COMMON_H -#define _BPF_PRELOAD_COMMON_H - -#define BPF_PRELOAD_START 0x5555 -#define BPF_PRELOAD_END 0xAAAA - -struct bpf_preload_info { - char link_name[16]; - int link_id; -}; - -#endif diff --git a/kernel/bpf/preload/iterators/iterators.c b/kernel/bpf/preload/iterators/iterators.c deleted file mode 100644 index 4dafe0f4f2b2..000000000000 --- a/kernel/bpf/preload/iterators/iterators.c +++ /dev/null @@ -1,108 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* Copyright (c) 2020 Facebook */ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include "iterators.lskel.h" -#include "bpf_preload_common.h" - -int to_kernel = -1; -int from_kernel = 0; - -static int __bpf_obj_get_info_by_fd(int bpf_fd, void *info, __u32 *info_len) -{ - union bpf_attr attr; - int err; - - memset(&attr, 0, sizeof(attr)); - attr.info.bpf_fd = bpf_fd; - attr.info.info_len = *info_len; - attr.info.info = (long) info; - - err = skel_sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr)); - if (!err) - *info_len = attr.info.info_len; - return err; -} - -static int send_link_to_kernel(int link_fd, const char *link_name) -{ - struct bpf_preload_info obj = {}; - struct bpf_link_info info = {}; - __u32 info_len = sizeof(info); - int err; - - err = __bpf_obj_get_info_by_fd(link_fd, &info, &info_len); - if (err) - return err; - obj.link_id = info.id; - if (strlen(link_name) >= sizeof(obj.link_name)) - return -E2BIG; - strcpy(obj.link_name, link_name); - if (write(to_kernel, &obj, sizeof(obj)) != sizeof(obj)) - return -EPIPE; - return 0; -} - -int main(int argc, char **argv) -{ - struct iterators_bpf *skel; - int err, magic; - int debug_fd; - - debug_fd = open("/dev/console", O_WRONLY | O_NOCTTY | O_CLOEXEC); - if (debug_fd < 0) - return 1; - to_kernel = dup(1); - close(1); - dup(debug_fd); - /* now stdin and stderr point to /dev/console */ - - read(from_kernel, &magic, sizeof(magic)); - if (magic != BPF_PRELOAD_START) { - printf("bad start magic %d\n", magic); - return 1; - } - /* libbpf opens BPF object and loads it into the kernel */ - skel = iterators_bpf__open_and_load(); - if (!skel) { - /* iterators.skel.h is little endian. - * libbpf doesn't support automatic little->big conversion - * of BPF bytecode yet. - * The program load will fail in such case. - */ - printf("Failed load could be due to wrong endianness\n"); - return 1; - } - err = iterators_bpf__attach(skel); - if (err) - goto cleanup; - - /* send two bpf_link IDs with names to the kernel */ - err = send_link_to_kernel(skel->links.dump_bpf_map_fd, "maps.debug"); - if (err) - goto cleanup; - err = send_link_to_kernel(skel->links.dump_bpf_prog_fd, "progs.debug"); - if (err) - goto cleanup; - - /* The kernel will proceed with pinnging the links in bpffs. - * UMD will wait on read from pipe. - */ - read(from_kernel, &magic, sizeof(magic)); - if (magic != BPF_PRELOAD_END) { - printf("bad final magic %d\n", magic); - err = -EINVAL; - } -cleanup: - iterators_bpf__destroy(skel); - - return err != 0; -} diff --git a/kernel/bpf/preload/iterators/iterators.lskel.h b/kernel/bpf/preload/iterators/iterators.lskel.h index d90562d672d2..70f236a82fe1 100644 --- a/kernel/bpf/preload/iterators/iterators.lskel.h +++ b/kernel/bpf/preload/iterators/iterators.lskel.h @@ -3,8 +3,6 @@ #ifndef __ITERATORS_BPF_SKEL_H__ #define __ITERATORS_BPF_SKEL_H__ -#include -#include #include struct iterators_bpf { @@ -70,31 +68,28 @@ iterators_bpf__destroy(struct iterators_bpf *skel) iterators_bpf__detach(skel); skel_closenz(skel->progs.dump_bpf_map.prog_fd); skel_closenz(skel->progs.dump_bpf_prog.prog_fd); - munmap(skel->rodata, 4096); + skel_free_map_data(skel->rodata, skel->maps.rodata.initial_value, 4096); skel_closenz(skel->maps.rodata.map_fd); - free(skel); + skel_free(skel); } static inline struct iterators_bpf * iterators_bpf__open(void) { struct iterators_bpf *skel; - skel = calloc(sizeof(*skel), 1); + skel = skel_alloc(sizeof(*skel)); if (!skel) goto cleanup; skel->ctx.sz = (void *)&skel->links - (void *)skel; - skel->rodata = - mmap(NULL, 4096, PROT_READ | PROT_WRITE, - MAP_SHARED | MAP_ANONYMOUS, -1, 0); - if (skel->rodata == (void *) -1) - goto cleanup; - memcpy(skel->rodata, (void *)"\ + skel->rodata = skel_prep_map_data((void *)"\ \x20\x20\x69\x64\x20\x6e\x61\x6d\x65\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\ \x20\x20\x20\x6d\x61\x78\x5f\x65\x6e\x74\x72\x69\x65\x73\x0a\0\x25\x34\x75\x20\ \x25\x2d\x31\x36\x73\x25\x36\x64\x0a\0\x20\x20\x69\x64\x20\x6e\x61\x6d\x65\x20\ \x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x61\x74\x74\x61\x63\x68\x65\ -\x64\x0a\0\x25\x34\x75\x20\x25\x2d\x31\x36\x73\x20\x25\x73\x20\x25\x73\x0a\0", 98); - skel->maps.rodata.initial_value = (__u64)(long)skel->rodata; +\x64\x0a\0\x25\x34\x75\x20\x25\x2d\x31\x36\x73\x20\x25\x73\x20\x25\x73\x0a\0", 4096, 98); + if (!skel->rodata) + goto cleanup; + skel->maps.rodata.initial_value = (__u64) (long) skel->rodata; return skel; cleanup: iterators_bpf__destroy(skel); @@ -326,7 +321,7 @@ iterators_bpf__load(struct iterators_bpf *skel) \0\0\x01\0\0\0\0\0\0\0\x13\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x10\0\0\0\0\0\ \0\0\x62\x70\x66\x5f\x69\x74\x65\x72\x5f\x62\x70\x66\x5f\x70\x72\x6f\x67\0\0\0\ \0\0\0\0"; - opts.insns_sz = 2184; + opts.insns_sz = 2216; opts.insns = (void *)"\ \xbf\x16\0\0\0\0\0\0\xbf\xa1\0\0\0\0\0\0\x07\x01\0\0\x78\xff\xff\xff\xb7\x02\0\ \0\x88\0\0\0\xb7\x03\0\0\0\0\0\0\x85\0\0\0\x71\0\0\0\x05\0\x14\0\0\0\0\0\x61\ @@ -343,70 +338,72 @@ iterators_bpf__load(struct iterators_bpf *skel) \0\0\x18\x62\0\0\0\0\0\0\0\0\0\0\x30\x0e\0\0\xb7\x03\0\0\x1c\0\0\0\x85\0\0\0\ \xa6\0\0\0\xbf\x07\0\0\0\0\0\0\xc5\x07\xd4\xff\0\0\0\0\x63\x7a\x78\xff\0\0\0\0\ \x61\xa0\x78\xff\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x80\x0e\0\0\x63\x01\0\0\0\ -\0\0\0\x61\x60\x20\0\0\0\0\0\x15\0\x03\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\ +\0\0\0\x61\x60\x1c\0\0\0\0\0\x15\0\x03\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\ \x5c\x0e\0\0\x63\x01\0\0\0\0\0\0\xb7\x01\0\0\0\0\0\0\x18\x62\0\0\0\0\0\0\0\0\0\ \0\x50\x0e\0\0\xb7\x03\0\0\x48\0\0\0\x85\0\0\0\xa6\0\0\0\xbf\x07\0\0\0\0\0\0\ \xc5\x07\xc3\xff\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x63\x71\0\0\0\0\0\ -\0\x79\x63\x18\0\0\0\0\0\x15\x03\x04\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x98\ -\x0e\0\0\xb7\x02\0\0\x62\0\0\0\x85\0\0\0\x94\0\0\0\x18\x62\0\0\0\0\0\0\0\0\0\0\ -\0\0\0\0\x61\x20\0\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x08\x0f\0\0\x63\x01\0\ -\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\0\x0f\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\ -\x10\x0f\0\0\x7b\x01\0\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\x98\x0e\0\0\x18\ -\x61\0\0\0\0\0\0\0\0\0\0\x18\x0f\0\0\x7b\x01\0\0\0\0\0\0\xb7\x01\0\0\x02\0\0\0\ -\x18\x62\0\0\0\0\0\0\0\0\0\0\x08\x0f\0\0\xb7\x03\0\0\x20\0\0\0\x85\0\0\0\xa6\0\ -\0\0\xbf\x07\0\0\0\0\0\0\xc5\x07\xa3\xff\0\0\0\0\x18\x62\0\0\0\0\0\0\0\0\0\0\0\ -\0\0\0\x61\x20\0\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x28\x0f\0\0\x63\x01\0\0\ -\0\0\0\0\xb7\x01\0\0\x16\0\0\0\x18\x62\0\0\0\0\0\0\0\0\0\0\x28\x0f\0\0\xb7\x03\ -\0\0\x04\0\0\0\x85\0\0\0\xa6\0\0\0\xbf\x07\0\0\0\0\0\0\xc5\x07\x96\xff\0\0\0\0\ -\x18\x60\0\0\0\0\0\0\0\0\0\0\x30\x0f\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x78\x11\0\ -\0\x7b\x01\0\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\x38\x0f\0\0\x18\x61\0\0\0\0\ -\0\0\0\0\0\0\x70\x11\0\0\x7b\x01\0\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\x40\ -\x10\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\xb8\x11\0\0\x7b\x01\0\0\0\0\0\0\x18\x60\0\ -\0\0\0\0\0\0\0\0\0\x48\x10\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\xc8\x11\0\0\x7b\x01\ -\0\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\xe8\x10\0\0\x18\x61\0\0\0\0\0\0\0\0\0\ -\0\xe8\x11\0\0\x7b\x01\0\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x18\x61\ -\0\0\0\0\0\0\0\0\0\0\xe0\x11\0\0\x7b\x01\0\0\0\0\0\0\x61\x60\x08\0\0\0\0\0\x18\ -\x61\0\0\0\0\0\0\0\0\0\0\x80\x11\0\0\x63\x01\0\0\0\0\0\0\x61\x60\x0c\0\0\0\0\0\ -\x18\x61\0\0\0\0\0\0\0\0\0\0\x84\x11\0\0\x63\x01\0\0\0\0\0\0\x79\x60\x10\0\0\0\ -\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x88\x11\0\0\x7b\x01\0\0\0\0\0\0\x61\xa0\x78\ -\xff\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\xb0\x11\0\0\x63\x01\0\0\0\0\0\0\x18\ -\x61\0\0\0\0\0\0\0\0\0\0\xf8\x11\0\0\xb7\x02\0\0\x11\0\0\0\xb7\x03\0\0\x0c\0\0\ -\0\xb7\x04\0\0\0\0\0\0\x85\0\0\0\xa7\0\0\0\xbf\x07\0\0\0\0\0\0\xc5\x07\x60\xff\ -\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\x68\x11\0\0\x63\x70\x6c\0\0\0\0\0\x77\x07\ -\0\0\x20\0\0\0\x63\x70\x70\0\0\0\0\0\xb7\x01\0\0\x05\0\0\0\x18\x62\0\0\0\0\0\0\ -\0\0\0\0\x68\x11\0\0\xb7\x03\0\0\x8c\0\0\0\x85\0\0\0\xa6\0\0\0\xbf\x07\0\0\0\0\ -\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\xd8\x11\0\0\x61\x01\0\0\0\0\0\0\xd5\x01\x02\0\ -\0\0\0\0\xbf\x19\0\0\0\0\0\0\x85\0\0\0\xa8\0\0\0\xc5\x07\x4e\xff\0\0\0\0\x63\ -\x7a\x80\xff\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\x10\x12\0\0\x18\x61\0\0\0\0\0\ -\0\0\0\0\0\x10\x17\0\0\x7b\x01\0\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\x18\x12\ -\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x08\x17\0\0\x7b\x01\0\0\0\0\0\0\x18\x60\0\0\0\ -\0\0\0\0\0\0\0\x28\x14\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x50\x17\0\0\x7b\x01\0\0\ -\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\x30\x14\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\ -\x60\x17\0\0\x7b\x01\0\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\xd0\x15\0\0\x18\ -\x61\0\0\0\0\0\0\0\0\0\0\x80\x17\0\0\x7b\x01\0\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\ -\0\0\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x78\x17\0\0\x7b\x01\0\0\0\0\0\0\x61\ -\x60\x08\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x18\x17\0\0\x63\x01\0\0\0\0\0\0\ -\x61\x60\x0c\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x1c\x17\0\0\x63\x01\0\0\0\0\ -\0\0\x79\x60\x10\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x20\x17\0\0\x7b\x01\0\0\ -\0\0\0\0\x61\xa0\x78\xff\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x48\x17\0\0\x63\ -\x01\0\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x90\x17\0\0\xb7\x02\0\0\x12\0\0\0\ -\xb7\x03\0\0\x0c\0\0\0\xb7\x04\0\0\0\0\0\0\x85\0\0\0\xa7\0\0\0\xbf\x07\0\0\0\0\ -\0\0\xc5\x07\x17\xff\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\0\x17\0\0\x63\x70\x6c\ -\0\0\0\0\0\x77\x07\0\0\x20\0\0\0\x63\x70\x70\0\0\0\0\0\xb7\x01\0\0\x05\0\0\0\ -\x18\x62\0\0\0\0\0\0\0\0\0\0\0\x17\0\0\xb7\x03\0\0\x8c\0\0\0\x85\0\0\0\xa6\0\0\ -\0\xbf\x07\0\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\x70\x17\0\0\x61\x01\0\0\0\0\ -\0\0\xd5\x01\x02\0\0\0\0\0\xbf\x19\0\0\0\0\0\0\x85\0\0\0\xa8\0\0\0\xc5\x07\x05\ -\xff\0\0\0\0\x63\x7a\x84\xff\0\0\0\0\x61\xa1\x78\xff\0\0\0\0\xd5\x01\x02\0\0\0\ -\0\0\xbf\x19\0\0\0\0\0\0\x85\0\0\0\xa8\0\0\0\x61\xa0\x80\xff\0\0\0\0\x63\x06\ -\x28\0\0\0\0\0\x61\xa0\x84\xff\0\0\0\0\x63\x06\x2c\0\0\0\0\0\x18\x61\0\0\0\0\0\ -\0\0\0\0\0\0\0\0\0\x61\x10\0\0\0\0\0\0\x63\x06\x18\0\0\0\0\0\xb7\0\0\0\0\0\0\0\ -\x95\0\0\0\0\0\0\0"; +\0\x79\x63\x20\0\0\0\0\0\x15\x03\x08\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x98\ +\x0e\0\0\xb7\x02\0\0\x62\0\0\0\x61\x60\x04\0\0\0\0\0\x45\0\x02\0\x01\0\0\0\x85\ +\0\0\0\x94\0\0\0\x05\0\x01\0\0\0\0\0\x85\0\0\0\x71\0\0\0\x18\x62\0\0\0\0\0\0\0\ +\0\0\0\0\0\0\0\x61\x20\0\0\0\0\0\0\x18\x61\0\0\0\0\0\0\0\0\0\0\x08\x0f\0\0\x63\ +\x01\0\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\0\x0f\0\0\x18\x61\0\0\0\0\0\0\0\0\ +\0\0\x10\x0f\0\0\x7b\x01\0\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\x98\x0e\0\0\ +\x18\x61\0\0\0\0\0\0\0\0\0\0\x18\x0f\0\0\x7b\x01\0\0\0\0\0\0\xb7\x01\0\0\x02\0\ +\0\0\x18\x62\0\0\0\0\0\0\0\0\0\0\x08\x0f\0\0\xb7\x03\0\0\x20\0\0\0\x85\0\0\0\ +\xa6\0\0\0\xbf\x07\0\0\0\0\0\0\xc5\x07\x9f\xff\0\0\0\0\x18\x62\0\0\0\0\0\0\0\0\ 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+\0\0\0\0\0\xc5\x07\x13\xff\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\0\x17\0\0\x63\ +\x70\x6c\0\0\0\0\0\x77\x07\0\0\x20\0\0\0\x63\x70\x70\0\0\0\0\0\xb7\x01\0\0\x05\ +\0\0\0\x18\x62\0\0\0\0\0\0\0\0\0\0\0\x17\0\0\xb7\x03\0\0\x8c\0\0\0\x85\0\0\0\ +\xa6\0\0\0\xbf\x07\0\0\0\0\0\0\x18\x60\0\0\0\0\0\0\0\0\0\0\x70\x17\0\0\x61\x01\ +\0\0\0\0\0\0\xd5\x01\x02\0\0\0\0\0\xbf\x19\0\0\0\0\0\0\x85\0\0\0\xa8\0\0\0\xc5\ +\x07\x01\xff\0\0\0\0\x63\x7a\x84\xff\0\0\0\0\x61\xa1\x78\xff\0\0\0\0\xd5\x01\ +\x02\0\0\0\0\0\xbf\x19\0\0\0\0\0\0\x85\0\0\0\xa8\0\0\0\x61\xa0\x80\xff\0\0\0\0\ +\x63\x06\x28\0\0\0\0\0\x61\xa0\x84\xff\0\0\0\0\x63\x06\x2c\0\0\0\0\0\x18\x61\0\ +\0\0\0\0\0\0\0\0\0\0\0\0\0\x61\x10\0\0\0\0\0\0\x63\x06\x18\0\0\0\0\0\xb7\0\0\0\ +\0\0\0\0\x95\0\0\0\0\0\0\0"; err = bpf_load_and_run(&opts); if (err < 0) return err; - skel->rodata = - mmap(skel->rodata, 4096, PROT_READ, MAP_SHARED | MAP_FIXED, - skel->maps.rodata.map_fd, 0); + skel->rodata = skel_finalize_map_data(&skel->maps.rodata.initial_value, + 4096, PROT_READ, skel->maps.rodata.map_fd); + if (!skel->rodata) + return -ENOMEM; return 0; } diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 753f3a3a7478..a72f63d5a7da 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -985,6 +985,7 @@ struct bpf_map *bpf_map_get(u32 ufd) return map; } +EXPORT_SYMBOL(bpf_map_get); struct bpf_map *bpf_map_get_with_uref(u32 ufd) { @@ -2492,6 +2493,7 @@ void bpf_link_put(struct bpf_link *link) bpf_link_free(link); } } +EXPORT_SYMBOL(bpf_link_put); static int bpf_link_release(struct inode *inode, struct file *filp) { @@ -2634,6 +2636,7 @@ struct bpf_link *bpf_link_get_from_fd(u32 ufd) return link; } +EXPORT_SYMBOL(bpf_link_get_from_fd); struct bpf_tracing_link { struct bpf_link link; @@ -4759,23 +4762,52 @@ static bool syscall_prog_is_valid_access(int off, int size, return true; } -BPF_CALL_3(bpf_sys_bpf, int, cmd, void *, attr, u32, attr_size) +BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) { + struct bpf_prog * __maybe_unused prog; + switch (cmd) { case BPF_MAP_CREATE: case BPF_MAP_UPDATE_ELEM: case BPF_MAP_FREEZE: case BPF_PROG_LOAD: case BPF_BTF_LOAD: + case BPF_LINK_CREATE: + case BPF_RAW_TRACEPOINT_OPEN: break; - /* case BPF_PROG_TEST_RUN: - * is not part of this list to prevent recursive test_run - */ +#ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ + case BPF_PROG_TEST_RUN: + if (attr->test.data_in || attr->test.data_out || + attr->test.ctx_out || attr->test.duration || + attr->test.repeat || attr->test.flags) + return -EINVAL; + + prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || + attr->test.ctx_size_in > U16_MAX) { + bpf_prog_put(prog); + return -EINVAL; + } + + if (!__bpf_prog_enter_sleepable(prog)) { + /* recursion detected */ + bpf_prog_put(prog); + return -EBUSY; + } + attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); + __bpf_prog_exit_sleepable(prog, 0 /* bpf_prog_run does runtime stats */); + bpf_prog_put(prog); + return 0; +#endif default: return -EINVAL; } return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size); } +EXPORT_SYMBOL(bpf_sys_bpf); static const struct bpf_func_proto bpf_sys_bpf_proto = { .func = bpf_sys_bpf, diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index bbef86cb4e72..d7473fee247c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1842,6 +1842,7 @@ static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id, s16 offset) struct bpf_kfunc_desc *desc; const char *func_name; struct btf *desc_btf; + unsigned long call_imm; unsigned long addr; int err; @@ -1926,9 +1927,17 @@ static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id, s16 offset) return -EINVAL; } + call_imm = BPF_CALL_IMM(addr); + /* Check whether or not the relative offset overflows desc->imm */ + if ((unsigned long)(s32)call_imm != call_imm) { + verbose(env, "address of kernel function %s is out of range\n", + func_name); + return -EINVAL; + } + desc = &tab->descs[tab->nr_descs++]; desc->func_id = func_id; - desc->imm = BPF_CALL_IMM(addr); + desc->imm = call_imm; desc->offset = offset; err = btf_distill_func_proto(&env->log, desc_btf, func_proto, func_name, diff --git a/tools/bpf/bpftool/Documentation/bpftool-gen.rst b/tools/bpf/bpftool/Documentation/bpftool-gen.rst index bc276388f432..18d646b571ec 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-gen.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-gen.rst @@ -25,6 +25,7 @@ GEN COMMANDS | **bpftool** **gen object** *OUTPUT_FILE* *INPUT_FILE* [*INPUT_FILE*...] | **bpftool** **gen skeleton** *FILE* [**name** *OBJECT_NAME*] +| **bpftool** **gen min_core_btf** *INPUT* *OUTPUT* *OBJECT* [*OBJECT*...] | **bpftool** **gen help** DESCRIPTION @@ -149,6 +150,26 @@ DESCRIPTION (non-read-only) data from userspace, with same simplicity as for BPF side. + **bpftool** **gen min_core_btf** *INPUT* *OUTPUT* *OBJECT* [*OBJECT*...] + Generate a minimum BTF file as *OUTPUT*, derived from a given + *INPUT* BTF file, containing all needed BTF types so one, or + more, given eBPF objects CO-RE relocations may be satisfied. + + When kernels aren't compiled with CONFIG_DEBUG_INFO_BTF, + libbpf, when loading an eBPF object, has to rely on external + BTF files to be able to calculate CO-RE relocations. + + Usually, an external BTF file is built from existing kernel + DWARF data using pahole. It contains all the types used by + its respective kernel image and, because of that, is big. + + The min_core_btf feature builds smaller BTF files, customized + to one or multiple eBPF objects, so they can be distributed + together with an eBPF CO-RE based application, turning the + application portable to different kernel versions. + + Check examples bellow for more information how to use it. + **bpftool gen help** Print short help message. @@ -215,7 +236,9 @@ This is example BPF application with two BPF programs and a mix of BPF maps and global variables. Source code is split across two source code files. **$ clang -target bpf -g example1.bpf.c -o example1.bpf.o** + **$ clang -target bpf -g example2.bpf.c -o example2.bpf.o** + **$ bpftool gen object example.bpf.o example1.bpf.o example2.bpf.o** This set of commands compiles *example1.bpf.c* and *example2.bpf.c* @@ -329,3 +352,70 @@ BPF ELF object file *example.bpf.o*. my_static_var: 7 This is a stripped-out version of skeleton generated for above example code. + +min_core_btf +------------ + +**$ bpftool btf dump file 5.4.0-example.btf format raw** + +:: + + [1] INT 'long unsigned int' size=8 bits_offset=0 nr_bits=64 encoding=(none) + [2] CONST '(anon)' type_id=1 + [3] VOLATILE '(anon)' type_id=1 + [4] ARRAY '(anon)' type_id=1 index_type_id=21 nr_elems=2 + [5] PTR '(anon)' type_id=8 + [6] CONST '(anon)' type_id=5 + [7] INT 'char' size=1 bits_offset=0 nr_bits=8 encoding=(none) + [8] CONST '(anon)' type_id=7 + [9] INT 'unsigned int' size=4 bits_offset=0 nr_bits=32 encoding=(none) + + +**$ bpftool btf dump file one.bpf.o format raw** + +:: + + [1] PTR '(anon)' type_id=2 + [2] STRUCT 'trace_event_raw_sys_enter' size=64 vlen=4 + 'ent' type_id=3 bits_offset=0 + 'id' type_id=7 bits_offset=64 + 'args' type_id=9 bits_offset=128 + '__data' type_id=12 bits_offset=512 + [3] STRUCT 'trace_entry' size=8 vlen=4 + 'type' type_id=4 bits_offset=0 + 'flags' type_id=5 bits_offset=16 + 'preempt_count' type_id=5 bits_offset=24 + + +**$ bpftool gen min_core_btf 5.4.0-example.btf 5.4.0-smaller.btf one.bpf.o** + +**$ bpftool btf dump file 5.4.0-smaller.btf format raw** + +:: + + [1] TYPEDEF 'pid_t' type_id=6 + [2] STRUCT 'trace_event_raw_sys_enter' size=64 vlen=1 + 'args' type_id=4 bits_offset=128 + [3] STRUCT 'task_struct' size=9216 vlen=2 + 'pid' type_id=1 bits_offset=17920 + 'real_parent' type_id=7 bits_offset=18048 + [4] ARRAY '(anon)' type_id=5 index_type_id=8 nr_elems=6 + [5] INT 'long unsigned int' size=8 bits_offset=0 nr_bits=64 encoding=(none) + [6] TYPEDEF '__kernel_pid_t' type_id=8 + [7] PTR '(anon)' type_id=3 + [8] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED + + +Now, the "5.4.0-smaller.btf" file may be used by libbpf as an external BTF file +when loading the "one.bpf.o" object into the "5.4.0-example" kernel. Note that +the generated BTF file won't allow other eBPF objects to be loaded, just the +ones given to min_core_btf. + +:: + + LIBBPF_OPTS(bpf_object_open_opts, opts, .btf_custom_path = "5.4.0-smaller.btf"); + struct bpf_object *obj; + + obj = bpf_object__open_file("one.bpf.o", &opts); + + ... diff --git a/tools/bpf/bpftool/Documentation/common_options.rst b/tools/bpf/bpftool/Documentation/common_options.rst index 908487b9c2ad..4107a586b68b 100644 --- a/tools/bpf/bpftool/Documentation/common_options.rst +++ b/tools/bpf/bpftool/Documentation/common_options.rst @@ -4,12 +4,13 @@ Print short help message (similar to **bpftool help**). -V, --version - Print version number (similar to **bpftool version**), and optional - features that were included when bpftool was compiled. Optional - features include linking against libbfd to provide the disassembler - for JIT-ted programs (**bpftool prog dump jited**) and usage of BPF - skeletons (some features like **bpftool prog profile** or showing - pids associated to BPF objects may rely on it). + Print bpftool's version number (similar to **bpftool version**), the + number of the libbpf version in use, and optional features that were + included when bpftool was compiled. Optional features include linking + against libbfd to provide the disassembler for JIT-ted programs + (**bpftool prog dump jited**) and usage of BPF skeletons (some + features like **bpftool prog profile** or showing pids associated to + BPF objects may rely on it). -j, --json Generate JSON output. For commands that cannot produce JSON, this diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index 83369f55df61..a137db96bd56 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -34,14 +34,10 @@ LIBBPF_BOOTSTRAP_INCLUDE := $(LIBBPF_BOOTSTRAP_DESTDIR)/include LIBBPF_BOOTSTRAP_HDRS_DIR := $(LIBBPF_BOOTSTRAP_INCLUDE)/bpf LIBBPF_BOOTSTRAP := $(LIBBPF_BOOTSTRAP_OUTPUT)libbpf.a -# We need to copy hashmap.h and nlattr.h which is not otherwise exported by -# libbpf, but still required by bpftool. -LIBBPF_INTERNAL_HDRS := $(addprefix $(LIBBPF_HDRS_DIR)/,hashmap.h nlattr.h) -LIBBPF_BOOTSTRAP_INTERNAL_HDRS := $(addprefix $(LIBBPF_BOOTSTRAP_HDRS_DIR)/,hashmap.h) - -ifeq ($(BPFTOOL_VERSION),) -BPFTOOL_VERSION := $(shell make -rR --no-print-directory -sC ../../.. kernelversion) -endif +# We need to copy hashmap.h, nlattr.h, relo_core.h and libbpf_internal.h +# which are not otherwise exported by libbpf, but still required by bpftool. +LIBBPF_INTERNAL_HDRS := $(addprefix $(LIBBPF_HDRS_DIR)/,hashmap.h nlattr.h relo_core.h libbpf_internal.h) +LIBBPF_BOOTSTRAP_INTERNAL_HDRS := $(addprefix $(LIBBPF_BOOTSTRAP_HDRS_DIR)/,hashmap.h relo_core.h libbpf_internal.h) $(LIBBPF_OUTPUT) $(BOOTSTRAP_OUTPUT) $(LIBBPF_BOOTSTRAP_OUTPUT) $(LIBBPF_HDRS_DIR) $(LIBBPF_BOOTSTRAP_HDRS_DIR): $(QUIET_MKDIR)mkdir -p $@ @@ -83,7 +79,9 @@ CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \ -I$(srctree)/kernel/bpf/ \ -I$(srctree)/tools/include \ -I$(srctree)/tools/include/uapi +ifneq ($(BPFTOOL_VERSION),) CFLAGS += -DBPFTOOL_VERSION='"$(BPFTOOL_VERSION)"' +endif ifneq ($(EXTRA_CFLAGS),) CFLAGS += $(EXTRA_CFLAGS) endif diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index 493753a4962e..958e1fd71b5c 100644 --- a/tools/bpf/bpftool/bash-completion/bpftool +++ b/tools/bpf/bpftool/bash-completion/bpftool @@ -1003,9 +1003,13 @@ _bpftool() ;; esac ;; + min_core_btf) + _filedir + return 0 + ;; *) [[ $prev == $object ]] && \ - COMPREPLY=( $( compgen -W 'object skeleton help' -- "$cur" ) ) + COMPREPLY=( $( compgen -W 'object skeleton help min_core_btf' -- "$cur" ) ) ;; esac ;; diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c index eacfc6a2060d..f8c1413523a3 100644 --- a/tools/bpf/bpftool/gen.c +++ b/tools/bpf/bpftool/gen.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -472,7 +473,7 @@ static void codegen_destroy(struct bpf_object *obj, const char *obj_name) continue; if (bpf_map__is_internal(map) && (bpf_map__map_flags(map) & BPF_F_MMAPABLE)) - printf("\tmunmap(skel->%1$s, %2$zd);\n", + printf("\tskel_free_map_data(skel->%1$s, skel->maps.%1$s.initial_value, %2$zd);\n", ident, bpf_map_mmap_sz(map)); codegen("\ \n\ @@ -481,7 +482,7 @@ static void codegen_destroy(struct bpf_object *obj, const char *obj_name) } codegen("\ \n\ - free(skel); \n\ + skel_free(skel); \n\ } \n\ ", obj_name); @@ -525,7 +526,7 @@ static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *h { \n\ struct %1$s *skel; \n\ \n\ - skel = calloc(sizeof(*skel), 1); \n\ + skel = skel_alloc(sizeof(*skel)); \n\ if (!skel) \n\ goto cleanup; \n\ skel->ctx.sz = (void *)&skel->links - (void *)skel; \n\ @@ -543,19 +544,18 @@ static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *h continue; codegen("\ - \n\ - skel->%1$s = \n\ - mmap(NULL, %2$zd, PROT_READ | PROT_WRITE,\n\ - MAP_SHARED | MAP_ANONYMOUS, -1, 0); \n\ - if (skel->%1$s == (void *) -1) \n\ - goto cleanup; \n\ - memcpy(skel->%1$s, (void *)\"\\ \n\ - ", ident, bpf_map_mmap_sz(map)); + \n\ + skel->%1$s = skel_prep_map_data((void *)\"\\ \n\ + ", ident); mmap_data = bpf_map__initial_value(map, &mmap_size); print_hex(mmap_data, mmap_size); - printf("\", %2$zd);\n" - "\tskel->maps.%1$s.initial_value = (__u64)(long)skel->%1$s;\n", - ident, mmap_size); + codegen("\ + \n\ + \", %1$zd, %2$zd); \n\ + if (!skel->%3$s) \n\ + goto cleanup; \n\ + skel->maps.%3$s.initial_value = (__u64) (long) skel->%3$s;\n\ + ", bpf_map_mmap_sz(map), mmap_size, ident); } codegen("\ \n\ @@ -611,9 +611,13 @@ static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *h else mmap_flags = "PROT_READ | PROT_WRITE"; - printf("\tskel->%1$s =\n" - "\t\tmmap(skel->%1$s, %2$zd, %3$s, MAP_SHARED | MAP_FIXED,\n" - "\t\t\tskel->maps.%1$s.map_fd, 0);\n", + codegen("\ + \n\ + skel->%1$s = skel_finalize_map_data(&skel->maps.%1$s.initial_value, \n\ + %2$zd, %3$s, skel->maps.%1$s.map_fd);\n\ + if (!skel->%1$s) \n\ + return -ENOMEM; \n\ + ", ident, bpf_map_mmap_sz(map), mmap_flags); } codegen("\ @@ -751,8 +755,6 @@ static int do_skeleton(int argc, char **argv) #ifndef %2$s \n\ #define %2$s \n\ \n\ - #include \n\ - #include \n\ #include \n\ \n\ struct %1$s { \n\ @@ -830,6 +832,16 @@ static int do_skeleton(int argc, char **argv) codegen("\ \n\ + \n\ + #ifdef __cplusplus \n\ + static inline struct %1$s *open(const struct bpf_object_open_opts *opts = nullptr);\n\ + static inline struct %1$s *open_and_load(); \n\ + static inline int load(struct %1$s *skel); \n\ + static inline int attach(struct %1$s *skel); \n\ + static inline void detach(struct %1$s *skel); \n\ + static inline void destroy(struct %1$s *skel); \n\ + static inline const void *elf_bytes(size_t *sz); \n\ + #endif /* __cplusplus */ \n\ }; \n\ \n\ static void \n\ @@ -1024,9 +1036,19 @@ static int do_skeleton(int argc, char **argv) \"; \n\ } \n\ \n\ - #endif /* %s */ \n\ + #ifdef __cplusplus \n\ + struct %1$s *%1$s::open(const struct bpf_object_open_opts *opts) { return %1$s__open_opts(opts); }\n\ + struct %1$s *%1$s::open_and_load() { return %1$s__open_and_load(); } \n\ + int %1$s::load(struct %1$s *skel) { return %1$s__load(skel); } \n\ + int %1$s::attach(struct %1$s *skel) { return %1$s__attach(skel); } \n\ + void %1$s::detach(struct %1$s *skel) { %1$s__detach(skel); } \n\ + void %1$s::destroy(struct %1$s *skel) { %1$s__destroy(skel); } \n\ + const void *%1$s::elf_bytes(size_t *sz) { return %1$s__elf_bytes(sz); } \n\ + #endif /* __cplusplus */ \n\ + \n\ + #endif /* %2$s */ \n\ ", - header_guard); + obj_name, header_guard); err = 0; out: bpf_object__close(obj); @@ -1087,6 +1109,7 @@ static int do_help(int argc, char **argv) fprintf(stderr, "Usage: %1$s %2$s object OUTPUT_FILE INPUT_FILE [INPUT_FILE...]\n" " %1$s %2$s skeleton FILE [name OBJECT_NAME]\n" + " %1$s %2$s min_core_btf INPUT OUTPUT OBJECT [OBJECT...]\n" " %1$s %2$s help\n" "\n" " " HELP_SPEC_OPTIONS " |\n" @@ -1097,10 +1120,593 @@ static int do_help(int argc, char **argv) return 0; } +static int btf_save_raw(const struct btf *btf, const char *path) +{ + const void *data; + FILE *f = NULL; + __u32 data_sz; + int err = 0; + + data = btf__raw_data(btf, &data_sz); + if (!data) + return -ENOMEM; + + f = fopen(path, "wb"); + if (!f) + return -errno; + + if (fwrite(data, 1, data_sz, f) != data_sz) + err = -errno; + + fclose(f); + return err; +} + +struct btfgen_info { + struct btf *src_btf; + struct btf *marked_btf; /* btf structure used to mark used types */ +}; + +static size_t btfgen_hash_fn(const void *key, void *ctx) +{ + return (size_t)key; +} + +static bool btfgen_equal_fn(const void *k1, const void *k2, void *ctx) +{ + return k1 == k2; +} + +static void *u32_as_hash_key(__u32 x) +{ + return (void *)(uintptr_t)x; +} + +static void btfgen_free_info(struct btfgen_info *info) +{ + if (!info) + return; + + btf__free(info->src_btf); + btf__free(info->marked_btf); + + free(info); +} + +static struct btfgen_info * +btfgen_new_info(const char *targ_btf_path) +{ + struct btfgen_info *info; + int err; + + info = calloc(1, sizeof(*info)); + if (!info) + return NULL; + + info->src_btf = btf__parse(targ_btf_path, NULL); + if (!info->src_btf) { + err = -errno; + p_err("failed parsing '%s' BTF file: %s", targ_btf_path, strerror(errno)); + goto err_out; + } + + info->marked_btf = btf__parse(targ_btf_path, NULL); + if (!info->marked_btf) { + err = -errno; + p_err("failed parsing '%s' BTF file: %s", targ_btf_path, strerror(errno)); + goto err_out; + } + + return info; + +err_out: + btfgen_free_info(info); + errno = -err; + return NULL; +} + +#define MARKED UINT32_MAX + +static void btfgen_mark_member(struct btfgen_info *info, int type_id, int idx) +{ + const struct btf_type *t = btf__type_by_id(info->marked_btf, type_id); + struct btf_member *m = btf_members(t) + idx; + + m->name_off = MARKED; +} + +static int +btfgen_mark_type(struct btfgen_info *info, unsigned int type_id, bool follow_pointers) +{ + const struct btf_type *btf_type = btf__type_by_id(info->src_btf, type_id); + struct btf_type *cloned_type; + struct btf_param *param; + struct btf_array *array; + int err, i; + + if (type_id == 0) + return 0; + + /* mark type on cloned BTF as used */ + cloned_type = (struct btf_type *) btf__type_by_id(info->marked_btf, type_id); + cloned_type->name_off = MARKED; + + /* recursively mark other types needed by it */ + switch (btf_kind(btf_type)) { + case BTF_KIND_UNKN: + case BTF_KIND_INT: + case BTF_KIND_FLOAT: + case BTF_KIND_ENUM: + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + break; + case BTF_KIND_PTR: + if (follow_pointers) { + err = btfgen_mark_type(info, btf_type->type, follow_pointers); + if (err) + return err; + } + break; + case BTF_KIND_CONST: + case BTF_KIND_VOLATILE: + case BTF_KIND_TYPEDEF: + err = btfgen_mark_type(info, btf_type->type, follow_pointers); + if (err) + return err; + break; + case BTF_KIND_ARRAY: + array = btf_array(btf_type); + + /* mark array type */ + err = btfgen_mark_type(info, array->type, follow_pointers); + /* mark array's index type */ + err = err ? : btfgen_mark_type(info, array->index_type, follow_pointers); + if (err) + return err; + break; + case BTF_KIND_FUNC_PROTO: + /* mark ret type */ + err = btfgen_mark_type(info, btf_type->type, follow_pointers); + if (err) + return err; + + /* mark parameters types */ + param = btf_params(btf_type); + for (i = 0; i < btf_vlen(btf_type); i++) { + err = btfgen_mark_type(info, param->type, follow_pointers); + if (err) + return err; + param++; + } + break; + /* tells if some other type needs to be handled */ + default: + p_err("unsupported kind: %s (%d)", btf_kind_str(btf_type), type_id); + return -EINVAL; + } + + return 0; +} + +static int btfgen_record_field_relo(struct btfgen_info *info, struct bpf_core_spec *targ_spec) +{ + struct btf *btf = info->src_btf; + const struct btf_type *btf_type; + struct btf_member *btf_member; + struct btf_array *array; + unsigned int type_id = targ_spec->root_type_id; + int idx, err; + + /* mark root type */ + btf_type = btf__type_by_id(btf, type_id); + err = btfgen_mark_type(info, type_id, false); + if (err) + return err; + + /* mark types for complex types (arrays, unions, structures) */ + for (int i = 1; i < targ_spec->raw_len; i++) { + /* skip typedefs and mods */ + while (btf_is_mod(btf_type) || btf_is_typedef(btf_type)) { + type_id = btf_type->type; + btf_type = btf__type_by_id(btf, type_id); + } + + switch (btf_kind(btf_type)) { + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + idx = targ_spec->raw_spec[i]; + btf_member = btf_members(btf_type) + idx; + + /* mark member */ + btfgen_mark_member(info, type_id, idx); + + /* mark member's type */ + type_id = btf_member->type; + btf_type = btf__type_by_id(btf, type_id); + err = btfgen_mark_type(info, type_id, false); + if (err) + return err; + break; + case BTF_KIND_ARRAY: + array = btf_array(btf_type); + type_id = array->type; + btf_type = btf__type_by_id(btf, type_id); + break; + default: + p_err("unsupported kind: %s (%d)", + btf_kind_str(btf_type), btf_type->type); + return -EINVAL; + } + } + + return 0; +} + +static int btfgen_record_type_relo(struct btfgen_info *info, struct bpf_core_spec *targ_spec) +{ + return btfgen_mark_type(info, targ_spec->root_type_id, true); +} + +static int btfgen_record_enumval_relo(struct btfgen_info *info, struct bpf_core_spec *targ_spec) +{ + return btfgen_mark_type(info, targ_spec->root_type_id, false); +} + +static int btfgen_record_reloc(struct btfgen_info *info, struct bpf_core_spec *res) +{ + switch (res->relo_kind) { + case BPF_CORE_FIELD_BYTE_OFFSET: + case BPF_CORE_FIELD_BYTE_SIZE: + case BPF_CORE_FIELD_EXISTS: + case BPF_CORE_FIELD_SIGNED: + case BPF_CORE_FIELD_LSHIFT_U64: + case BPF_CORE_FIELD_RSHIFT_U64: + return btfgen_record_field_relo(info, res); + case BPF_CORE_TYPE_ID_LOCAL: /* BPF_CORE_TYPE_ID_LOCAL doesn't require kernel BTF */ + return 0; + case BPF_CORE_TYPE_ID_TARGET: + case BPF_CORE_TYPE_EXISTS: + case BPF_CORE_TYPE_SIZE: + return btfgen_record_type_relo(info, res); + case BPF_CORE_ENUMVAL_EXISTS: + case BPF_CORE_ENUMVAL_VALUE: + return btfgen_record_enumval_relo(info, res); + default: + return -EINVAL; + } +} + +static struct bpf_core_cand_list * +btfgen_find_cands(const struct btf *local_btf, const struct btf *targ_btf, __u32 local_id) +{ + const struct btf_type *local_type; + struct bpf_core_cand_list *cands = NULL; + struct bpf_core_cand local_cand = {}; + size_t local_essent_len; + const char *local_name; + int err; + + local_cand.btf = local_btf; + local_cand.id = local_id; + + local_type = btf__type_by_id(local_btf, local_id); + if (!local_type) { + err = -EINVAL; + goto err_out; + } + + local_name = btf__name_by_offset(local_btf, local_type->name_off); + if (!local_name) { + err = -EINVAL; + goto err_out; + } + local_essent_len = bpf_core_essential_name_len(local_name); + + cands = calloc(1, sizeof(*cands)); + if (!cands) + return NULL; + + err = bpf_core_add_cands(&local_cand, local_essent_len, targ_btf, "vmlinux", 1, cands); + if (err) + goto err_out; + + return cands; + +err_out: + bpf_core_free_cands(cands); + errno = -err; + return NULL; +} + +/* Record relocation information for a single BPF object */ +static int btfgen_record_obj(struct btfgen_info *info, const char *obj_path) +{ + const struct btf_ext_info_sec *sec; + const struct bpf_core_relo *relo; + const struct btf_ext_info *seg; + struct hashmap_entry *entry; + struct hashmap *cand_cache = NULL; + struct btf_ext *btf_ext = NULL; + unsigned int relo_idx; + struct btf *btf = NULL; + size_t i; + int err; + + btf = btf__parse(obj_path, &btf_ext); + if (!btf) { + err = -errno; + p_err("failed to parse BPF object '%s': %s", obj_path, strerror(errno)); + return err; + } + + if (!btf_ext) { + p_err("failed to parse BPF object '%s': section %s not found", + obj_path, BTF_EXT_ELF_SEC); + err = -EINVAL; + goto out; + } + + if (btf_ext->core_relo_info.len == 0) { + err = 0; + goto out; + } + + cand_cache = hashmap__new(btfgen_hash_fn, btfgen_equal_fn, NULL); + if (IS_ERR(cand_cache)) { + err = PTR_ERR(cand_cache); + goto out; + } + + seg = &btf_ext->core_relo_info; + for_each_btf_ext_sec(seg, sec) { + for_each_btf_ext_rec(seg, sec, relo_idx, relo) { + struct bpf_core_spec specs_scratch[3] = {}; + struct bpf_core_relo_res targ_res = {}; + struct bpf_core_cand_list *cands = NULL; + const void *type_key = u32_as_hash_key(relo->type_id); + const char *sec_name = btf__name_by_offset(btf, sec->sec_name_off); + + if (relo->kind != BPF_CORE_TYPE_ID_LOCAL && + !hashmap__find(cand_cache, type_key, (void **)&cands)) { + cands = btfgen_find_cands(btf, info->src_btf, relo->type_id); + if (!cands) { + err = -errno; + goto out; + } + + err = hashmap__set(cand_cache, type_key, cands, NULL, NULL); + if (err) + goto out; + } + + err = bpf_core_calc_relo_insn(sec_name, relo, relo_idx, btf, cands, + specs_scratch, &targ_res); + if (err) + goto out; + + /* specs_scratch[2] is the target spec */ + err = btfgen_record_reloc(info, &specs_scratch[2]); + if (err) + goto out; + } + } + +out: + btf__free(btf); + btf_ext__free(btf_ext); + + if (!IS_ERR_OR_NULL(cand_cache)) { + hashmap__for_each_entry(cand_cache, entry, i) { + bpf_core_free_cands(entry->value); + } + hashmap__free(cand_cache); + } + + return err; +} + +static int btfgen_remap_id(__u32 *type_id, void *ctx) +{ + unsigned int *ids = ctx; + + *type_id = ids[*type_id]; + + return 0; +} + +/* Generate BTF from relocation information previously recorded */ +static struct btf *btfgen_get_btf(struct btfgen_info *info) +{ + struct btf *btf_new = NULL; + unsigned int *ids = NULL; + unsigned int i, n = btf__type_cnt(info->marked_btf); + int err = 0; + + btf_new = btf__new_empty(); + if (!btf_new) { + err = -errno; + goto err_out; + } + + ids = calloc(n, sizeof(*ids)); + if (!ids) { + err = -errno; + goto err_out; + } + + /* first pass: add all marked types to btf_new and add their new ids to the ids map */ + for (i = 1; i < n; i++) { + const struct btf_type *cloned_type, *type; + const char *name; + int new_id; + + cloned_type = btf__type_by_id(info->marked_btf, i); + + if (cloned_type->name_off != MARKED) + continue; + + type = btf__type_by_id(info->src_btf, i); + + /* add members for struct and union */ + if (btf_is_composite(type)) { + struct btf_member *cloned_m, *m; + unsigned short vlen; + int idx_src; + + name = btf__str_by_offset(info->src_btf, type->name_off); + + if (btf_is_struct(type)) + err = btf__add_struct(btf_new, name, type->size); + else + err = btf__add_union(btf_new, name, type->size); + + if (err < 0) + goto err_out; + new_id = err; + + cloned_m = btf_members(cloned_type); + m = btf_members(type); + vlen = btf_vlen(cloned_type); + for (idx_src = 0; idx_src < vlen; idx_src++, cloned_m++, m++) { + /* add only members that are marked as used */ + if (cloned_m->name_off != MARKED) + continue; + + name = btf__str_by_offset(info->src_btf, m->name_off); + err = btf__add_field(btf_new, name, m->type, + btf_member_bit_offset(cloned_type, idx_src), + btf_member_bitfield_size(cloned_type, idx_src)); + if (err < 0) + goto err_out; + } + } else { + err = btf__add_type(btf_new, info->src_btf, type); + if (err < 0) + goto err_out; + new_id = err; + } + + /* add ID mapping */ + ids[i] = new_id; + } + + /* second pass: fix up type ids */ + for (i = 1; i < btf__type_cnt(btf_new); i++) { + struct btf_type *btf_type = (struct btf_type *) btf__type_by_id(btf_new, i); + + err = btf_type_visit_type_ids(btf_type, btfgen_remap_id, ids); + if (err) + goto err_out; + } + + free(ids); + return btf_new; + +err_out: + btf__free(btf_new); + free(ids); + errno = -err; + return NULL; +} + +/* Create minimized BTF file for a set of BPF objects. + * + * The BTFGen algorithm is divided in two main parts: (1) collect the + * BTF types that are involved in relocations and (2) generate the BTF + * object using the collected types. + * + * In order to collect the types involved in the relocations, we parse + * the BTF and BTF.ext sections of the BPF objects and use + * bpf_core_calc_relo_insn() to get the target specification, this + * indicates how the types and fields are used in a relocation. + * + * Types are recorded in different ways according to the kind of the + * relocation. For field-based relocations only the members that are + * actually used are saved in order to reduce the size of the generated + * BTF file. For type-based relocations empty struct / unions are + * generated and for enum-based relocations the whole type is saved. + * + * The second part of the algorithm generates the BTF object. It creates + * an empty BTF object and fills it with the types recorded in the + * previous step. This function takes care of only adding the structure + * and union members that were marked as used and it also fixes up the + * type IDs on the generated BTF object. + */ +static int minimize_btf(const char *src_btf, const char *dst_btf, const char *objspaths[]) +{ + struct btfgen_info *info; + struct btf *btf_new = NULL; + int err, i; + + info = btfgen_new_info(src_btf); + if (!info) { + err = -errno; + p_err("failed to allocate info structure: %s", strerror(errno)); + goto out; + } + + for (i = 0; objspaths[i] != NULL; i++) { + err = btfgen_record_obj(info, objspaths[i]); + if (err) { + p_err("error recording relocations for %s: %s", objspaths[i], + strerror(errno)); + goto out; + } + } + + btf_new = btfgen_get_btf(info); + if (!btf_new) { + err = -errno; + p_err("error generating BTF: %s", strerror(errno)); + goto out; + } + + err = btf_save_raw(btf_new, dst_btf); + if (err) { + p_err("error saving btf file: %s", strerror(errno)); + goto out; + } + +out: + btf__free(btf_new); + btfgen_free_info(info); + + return err; +} + +static int do_min_core_btf(int argc, char **argv) +{ + const char *input, *output, **objs; + int i, err; + + if (!REQ_ARGS(3)) { + usage(); + return -1; + } + + input = GET_ARG(); + output = GET_ARG(); + + objs = (const char **) calloc(argc + 1, sizeof(*objs)); + if (!objs) { + p_err("failed to allocate array for object names"); + return -ENOMEM; + } + + i = 0; + while (argc) + objs[i++] = GET_ARG(); + + err = minimize_btf(input, output, objs); + free(objs); + return err; +} + static const struct cmd cmds[] = { - { "object", do_object }, - { "skeleton", do_skeleton }, - { "help", do_help }, + { "object", do_object }, + { "skeleton", do_skeleton }, + { "min_core_btf", do_min_core_btf}, + { "help", do_help }, { 0 } }; diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c index 490f7bd54e4c..e81227761f5d 100644 --- a/tools/bpf/bpftool/main.c +++ b/tools/bpf/bpftool/main.c @@ -71,6 +71,17 @@ static int do_help(int argc, char **argv) return 0; } +#ifndef BPFTOOL_VERSION +/* bpftool's major and minor version numbers are aligned on libbpf's. There is + * an offset of 6 for the version number, because bpftool's version was higher + * than libbpf's when we adopted this scheme. The patch number remains at 0 + * for now. Set BPFTOOL_VERSION to override. + */ +#define BPFTOOL_MAJOR_VERSION (LIBBPF_MAJOR_VERSION + 6) +#define BPFTOOL_MINOR_VERSION LIBBPF_MINOR_VERSION +#define BPFTOOL_PATCH_VERSION 0 +#endif + static int do_version(int argc, char **argv) { #ifdef HAVE_LIBBFD_SUPPORT @@ -88,7 +99,15 @@ static int do_version(int argc, char **argv) jsonw_start_object(json_wtr); /* root object */ jsonw_name(json_wtr, "version"); +#ifdef BPFTOOL_VERSION jsonw_printf(json_wtr, "\"%s\"", BPFTOOL_VERSION); +#else + jsonw_printf(json_wtr, "\"%d.%d.%d\"", BPFTOOL_MAJOR_VERSION, + BPFTOOL_MINOR_VERSION, BPFTOOL_PATCH_VERSION); +#endif + jsonw_name(json_wtr, "libbpf_version"); + jsonw_printf(json_wtr, "\"%d.%d\"", + libbpf_major_version(), libbpf_minor_version()); jsonw_name(json_wtr, "features"); jsonw_start_object(json_wtr); /* features */ @@ -101,7 +120,13 @@ static int do_version(int argc, char **argv) } else { unsigned int nb_features = 0; +#ifdef BPFTOOL_VERSION printf("%s v%s\n", bin_name, BPFTOOL_VERSION); +#else + printf("%s v%d.%d.%d\n", bin_name, BPFTOOL_MAJOR_VERSION, + BPFTOOL_MINOR_VERSION, BPFTOOL_PATCH_VERSION); +#endif + printf("using libbpf %s\n", libbpf_version_string()); printf("features:"); if (has_libbfd) { printf(" libbfd"); diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index c66a3c979b7a..e746642de292 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -805,29 +805,30 @@ static int maps_have_btf(int *fds, int nb_fds) static struct btf *btf_vmlinux; -static struct btf *get_map_kv_btf(const struct bpf_map_info *info) +static int get_map_kv_btf(const struct bpf_map_info *info, struct btf **btf) { - struct btf *btf = NULL; + int err = 0; if (info->btf_vmlinux_value_type_id) { if (!btf_vmlinux) { btf_vmlinux = libbpf_find_kernel_btf(); - if (libbpf_get_error(btf_vmlinux)) + err = libbpf_get_error(btf_vmlinux); + if (err) { p_err("failed to get kernel btf"); + return err; + } } - return btf_vmlinux; + *btf = btf_vmlinux; } else if (info->btf_value_type_id) { - int err; - - btf = btf__load_from_kernel_by_id(info->btf_id); - err = libbpf_get_error(btf); - if (err) { + *btf = btf__load_from_kernel_by_id(info->btf_id); + err = libbpf_get_error(*btf); + if (err) p_err("failed to get btf"); - btf = ERR_PTR(err); - } + } else { + *btf = NULL; } - return btf; + return err; } static void free_map_kv_btf(struct btf *btf) @@ -862,8 +863,7 @@ map_dump(int fd, struct bpf_map_info *info, json_writer_t *wtr, prev_key = NULL; if (wtr) { - btf = get_map_kv_btf(info); - err = libbpf_get_error(btf); + err = get_map_kv_btf(info, &btf); if (err) { goto exit_free; } @@ -1054,11 +1054,8 @@ static void print_key_value(struct bpf_map_info *info, void *key, json_writer_t *btf_wtr; struct btf *btf; - btf = btf__load_from_kernel_by_id(info->btf_id); - if (libbpf_get_error(btf)) { - p_err("failed to get btf"); + if (get_map_kv_btf(info, &btf)) return; - } if (json_output) { print_entry_json(info, key, value, btf); diff --git a/tools/lib/bpf/gen_loader.c b/tools/lib/bpf/gen_loader.c index 8ecef1088ba2..927745b08014 100644 --- a/tools/lib/bpf/gen_loader.c +++ b/tools/lib/bpf/gen_loader.c @@ -1043,18 +1043,27 @@ void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *pvalue, value = add_data(gen, pvalue, value_size); key = add_data(gen, &zero, sizeof(zero)); - /* if (map_desc[map_idx].initial_value) - * copy_from_user(value, initial_value, value_size); + /* if (map_desc[map_idx].initial_value) { + * if (ctx->flags & BPF_SKEL_KERNEL) + * bpf_probe_read_kernel(value, value_size, initial_value); + * else + * bpf_copy_from_user(value, value_size, initial_value); + * } */ emit(gen, BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_6, sizeof(struct bpf_loader_ctx) + sizeof(struct bpf_map_desc) * map_idx + offsetof(struct bpf_map_desc, initial_value))); - emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0, 4)); + emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0, 8)); emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 0, 0, 0, value)); emit(gen, BPF_MOV64_IMM(BPF_REG_2, value_size)); + emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6, + offsetof(struct bpf_loader_ctx, flags))); + emit(gen, BPF_JMP_IMM(BPF_JSET, BPF_REG_0, BPF_SKEL_KERNEL, 2)); emit(gen, BPF_EMIT_CALL(BPF_FUNC_copy_from_user)); + emit(gen, BPF_JMP_IMM(BPF_JA, 0, 0, 1)); + emit(gen, BPF_EMIT_CALL(BPF_FUNC_probe_read_kernel)); map_update_attr = add_data(gen, &attr, attr_size); move_blob2blob(gen, attr_field(map_update_attr, map_fd), 4, diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 2262bcdfee92..ad43b6ce825e 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -5192,18 +5192,21 @@ size_t bpf_core_essential_name_len(const char *name) return n; } -static void bpf_core_free_cands(struct bpf_core_cand_list *cands) +void bpf_core_free_cands(struct bpf_core_cand_list *cands) { + if (!cands) + return; + free(cands->cands); free(cands); } -static int bpf_core_add_cands(struct bpf_core_cand *local_cand, - size_t local_essent_len, - const struct btf *targ_btf, - const char *targ_btf_name, - int targ_start_id, - struct bpf_core_cand_list *cands) +int bpf_core_add_cands(struct bpf_core_cand *local_cand, + size_t local_essent_len, + const struct btf *targ_btf, + const char *targ_btf_name, + int targ_start_id, + struct bpf_core_cand_list *cands) { struct bpf_core_cand *new_cands, *cand; const struct btf_type *t, *local_t; @@ -5530,11 +5533,12 @@ static int record_relo_core(struct bpf_program *prog, return 0; } -static int bpf_core_apply_relo(struct bpf_program *prog, - const struct bpf_core_relo *relo, - int relo_idx, - const struct btf *local_btf, - struct hashmap *cand_cache) +static int bpf_core_resolve_relo(struct bpf_program *prog, + const struct bpf_core_relo *relo, + int relo_idx, + const struct btf *local_btf, + struct hashmap *cand_cache, + struct bpf_core_relo_res *targ_res) { struct bpf_core_spec specs_scratch[3] = {}; const void *type_key = u32_as_hash_key(relo->type_id); @@ -5543,20 +5547,7 @@ static int bpf_core_apply_relo(struct bpf_program *prog, const struct btf_type *local_type; const char *local_name; __u32 local_id = relo->type_id; - struct bpf_insn *insn; - int insn_idx, err; - - if (relo->insn_off % BPF_INSN_SZ) - return -EINVAL; - insn_idx = relo->insn_off / BPF_INSN_SZ; - /* adjust insn_idx from section frame of reference to the local - * program's frame of reference; (sub-)program code is not yet - * relocated, so it's enough to just subtract in-section offset - */ - insn_idx = insn_idx - prog->sec_insn_off; - if (insn_idx >= prog->insns_cnt) - return -EINVAL; - insn = &prog->insns[insn_idx]; + int err; local_type = btf__type_by_id(local_btf, local_id); if (!local_type) @@ -5566,15 +5557,6 @@ static int bpf_core_apply_relo(struct bpf_program *prog, if (!local_name) return -EINVAL; - if (prog->obj->gen_loader) { - const char *spec_str = btf__name_by_offset(local_btf, relo->access_str_off); - - pr_debug("record_relo_core: prog %td insn[%d] %s %s %s final insn_idx %d\n", - prog - prog->obj->programs, relo->insn_off / 8, - btf_kind_str(local_type), local_name, spec_str, insn_idx); - return record_relo_core(prog, relo, insn_idx); - } - if (relo->kind != BPF_CORE_TYPE_ID_LOCAL && !hashmap__find(cand_cache, type_key, (void **)&cands)) { cands = bpf_core_find_cands(prog->obj, local_btf, local_id); @@ -5591,19 +5573,21 @@ static int bpf_core_apply_relo(struct bpf_program *prog, } } - return bpf_core_apply_relo_insn(prog_name, insn, insn_idx, relo, - relo_idx, local_btf, cands, specs_scratch); + return bpf_core_calc_relo_insn(prog_name, relo, relo_idx, local_btf, cands, specs_scratch, + targ_res); } static int bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) { const struct btf_ext_info_sec *sec; + struct bpf_core_relo_res targ_res; const struct bpf_core_relo *rec; const struct btf_ext_info *seg; struct hashmap_entry *entry; struct hashmap *cand_cache = NULL; struct bpf_program *prog; + struct bpf_insn *insn; const char *sec_name; int i, err = 0, insn_idx, sec_idx; @@ -5654,6 +5638,8 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) sec_name, sec->num_info); for_each_btf_ext_rec(seg, sec, i, rec) { + if (rec->insn_off % BPF_INSN_SZ) + return -EINVAL; insn_idx = rec->insn_off / BPF_INSN_SZ; prog = find_prog_by_sec_insn(obj, sec_idx, insn_idx); if (!prog) { @@ -5668,12 +5654,38 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) if (!prog->load) continue; - err = bpf_core_apply_relo(prog, rec, i, obj->btf, cand_cache); + /* adjust insn_idx from section frame of reference to the local + * program's frame of reference; (sub-)program code is not yet + * relocated, so it's enough to just subtract in-section offset + */ + insn_idx = insn_idx - prog->sec_insn_off; + if (insn_idx >= prog->insns_cnt) + return -EINVAL; + insn = &prog->insns[insn_idx]; + + if (prog->obj->gen_loader) { + err = record_relo_core(prog, rec, insn_idx); + if (err) { + pr_warn("prog '%s': relo #%d: failed to record relocation: %d\n", + prog->name, i, err); + goto out; + } + continue; + } + + err = bpf_core_resolve_relo(prog, rec, i, obj->btf, cand_cache, &targ_res); if (err) { pr_warn("prog '%s': relo #%d: failed to relocate: %d\n", prog->name, i, err); goto out; } + + err = bpf_core_patch_insn(prog->name, insn, insn_idx, rec, i, &targ_res); + if (err) { + pr_warn("prog '%s': relo #%d: failed to patch insn #%u: %d\n", + prog->name, i, insn_idx, err); + goto out; + } } } diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index aef6253a90c8..47e70c9058d9 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -438,4 +438,4 @@ LIBBPF_0.7.0 { libbpf_probe_bpf_map_type; libbpf_probe_bpf_prog_type; libbpf_set_memlock_rlim_max; -}; +} LIBBPF_0.6.0; diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index bc86b82e90d1..4fda8bdf0a0d 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -529,4 +529,13 @@ static inline int ensure_good_fd(int fd) return fd; } +/* The following two functions are exposed to bpftool */ +int bpf_core_add_cands(struct bpf_core_cand *local_cand, + size_t local_essent_len, + const struct btf *targ_btf, + const char *targ_btf_name, + int targ_start_id, + struct bpf_core_cand_list *cands); +void bpf_core_free_cands(struct bpf_core_cand_list *cands); + #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c index c39c37f99d5c..cbc8967d5402 100644 --- a/tools/lib/bpf/netlink.c +++ b/tools/lib/bpf/netlink.c @@ -87,29 +87,75 @@ enum { NL_DONE, }; +static int netlink_recvmsg(int sock, struct msghdr *mhdr, int flags) +{ + int len; + + do { + len = recvmsg(sock, mhdr, flags); + } while (len < 0 && (errno == EINTR || errno == EAGAIN)); + + if (len < 0) + return -errno; + return len; +} + +static int alloc_iov(struct iovec *iov, int len) +{ + void *nbuf; + + nbuf = realloc(iov->iov_base, len); + if (!nbuf) + return -ENOMEM; + + iov->iov_base = nbuf; + iov->iov_len = len; + return 0; +} + static int libbpf_netlink_recv(int sock, __u32 nl_pid, int seq, __dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn, void *cookie) { + struct iovec iov = {}; + struct msghdr mhdr = { + .msg_iov = &iov, + .msg_iovlen = 1, + }; bool multipart = true; struct nlmsgerr *err; struct nlmsghdr *nh; - char buf[4096]; int len, ret; + ret = alloc_iov(&iov, 4096); + if (ret) + goto done; + while (multipart) { start: multipart = false; - len = recv(sock, buf, sizeof(buf), 0); + len = netlink_recvmsg(sock, &mhdr, MSG_PEEK | MSG_TRUNC); if (len < 0) { - ret = -errno; + ret = len; + goto done; + } + + if (len > iov.iov_len) { + ret = alloc_iov(&iov, len); + if (ret) + goto done; + } + + len = netlink_recvmsg(sock, &mhdr, 0); + if (len < 0) { + ret = len; goto done; } if (len == 0) break; - for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len); + for (nh = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(nh, len); nh = NLMSG_NEXT(nh, len)) { if (nh->nlmsg_pid != nl_pid) { ret = -LIBBPF_ERRNO__WRNGPID; @@ -130,7 +176,8 @@ static int libbpf_netlink_recv(int sock, __u32 nl_pid, int seq, libbpf_nla_dump_errormsg(nh); goto done; case NLMSG_DONE: - return 0; + ret = 0; + goto done; default: break; } @@ -142,15 +189,17 @@ static int libbpf_netlink_recv(int sock, __u32 nl_pid, int seq, case NL_NEXT: goto start; case NL_DONE: - return 0; + ret = 0; + goto done; default: - return ret; + goto done; } } } } ret = 0; done: + free(iov.iov_base); return ret; } diff --git a/tools/lib/bpf/relo_core.c b/tools/lib/bpf/relo_core.c index 910865e29edc..f946f23eab20 100644 --- a/tools/lib/bpf/relo_core.c +++ b/tools/lib/bpf/relo_core.c @@ -775,31 +775,6 @@ static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo, return 0; } -struct bpf_core_relo_res -{ - /* expected value in the instruction, unless validate == false */ - __u32 orig_val; - /* new value that needs to be patched up to */ - __u32 new_val; - /* relocation unsuccessful, poison instruction, but don't fail load */ - bool poison; - /* some relocations can't be validated against orig_val */ - bool validate; - /* for field byte offset relocations or the forms: - * *(T *)(rX + ) = rY - * rX = *(T *)(rY + ), - * we remember original and resolved field size to adjust direct - * memory loads of pointers and integers; this is necessary for 32-bit - * host kernel architectures, but also allows to automatically - * relocate fields that were resized from, e.g., u32 to u64, etc. - */ - bool fail_memsz_adjust; - __u32 orig_sz; - __u32 orig_type_id; - __u32 new_sz; - __u32 new_type_id; -}; - /* Calculate original and target relocation values, given local and target * specs and relocation kind. These values are calculated for each candidate. * If there are multiple candidates, resulting values should all be consistent @@ -951,9 +926,9 @@ static int insn_bytes_to_bpf_size(__u32 sz) * 5. *(T *)(rX + ) = rY, where T is one of {u8, u16, u32, u64}; * 6. *(T *)(rX + ) = , where T is one of {u8, u16, u32, u64}. */ -static int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn, - int insn_idx, const struct bpf_core_relo *relo, - int relo_idx, const struct bpf_core_relo_res *res) +int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn, + int insn_idx, const struct bpf_core_relo *relo, + int relo_idx, const struct bpf_core_relo_res *res) { __u32 orig_val, new_val; __u8 class; @@ -1128,7 +1103,7 @@ static void bpf_core_dump_spec(const char *prog_name, int level, const struct bp } /* - * CO-RE relocate single instruction. + * Calculate CO-RE relocation target result. * * The outline and important points of the algorithm: * 1. For given local type, find corresponding candidate target types. @@ -1177,18 +1152,18 @@ static void bpf_core_dump_spec(const char *prog_name, int level, const struct bp * between multiple relocations for the same type ID and is updated as some * of the candidates are pruned due to structural incompatibility. */ -int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn, - int insn_idx, - const struct bpf_core_relo *relo, - int relo_idx, - const struct btf *local_btf, - struct bpf_core_cand_list *cands, - struct bpf_core_spec *specs_scratch) +int bpf_core_calc_relo_insn(const char *prog_name, + const struct bpf_core_relo *relo, + int relo_idx, + const struct btf *local_btf, + struct bpf_core_cand_list *cands, + struct bpf_core_spec *specs_scratch, + struct bpf_core_relo_res *targ_res) { struct bpf_core_spec *local_spec = &specs_scratch[0]; struct bpf_core_spec *cand_spec = &specs_scratch[1]; struct bpf_core_spec *targ_spec = &specs_scratch[2]; - struct bpf_core_relo_res cand_res, targ_res; + struct bpf_core_relo_res cand_res; const struct btf_type *local_type; const char *local_name; __u32 local_id; @@ -1223,12 +1198,12 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn, /* TYPE_ID_LOCAL relo is special and doesn't need candidate search */ if (relo->kind == BPF_CORE_TYPE_ID_LOCAL) { /* bpf_insn's imm value could get out of sync during linking */ - memset(&targ_res, 0, sizeof(targ_res)); - targ_res.validate = false; - targ_res.poison = false; - targ_res.orig_val = local_spec->root_type_id; - targ_res.new_val = local_spec->root_type_id; - goto patch_insn; + memset(targ_res, 0, sizeof(*targ_res)); + targ_res->validate = false; + targ_res->poison = false; + targ_res->orig_val = local_spec->root_type_id; + targ_res->new_val = local_spec->root_type_id; + return 0; } /* libbpf doesn't support candidate search for anonymous types */ @@ -1262,7 +1237,7 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn, return err; if (j == 0) { - targ_res = cand_res; + *targ_res = cand_res; *targ_spec = *cand_spec; } else if (cand_spec->bit_offset != targ_spec->bit_offset) { /* if there are many field relo candidates, they @@ -1272,7 +1247,8 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn, prog_name, relo_idx, cand_spec->bit_offset, targ_spec->bit_offset); return -EINVAL; - } else if (cand_res.poison != targ_res.poison || cand_res.new_val != targ_res.new_val) { + } else if (cand_res.poison != targ_res->poison || + cand_res.new_val != targ_res->new_val) { /* all candidates should result in the same relocation * decision and value, otherwise it's dangerous to * proceed due to ambiguity @@ -1280,7 +1256,7 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn, pr_warn("prog '%s': relo #%d: relocation decision ambiguity: %s %u != %s %u\n", prog_name, relo_idx, cand_res.poison ? "failure" : "success", cand_res.new_val, - targ_res.poison ? "failure" : "success", targ_res.new_val); + targ_res->poison ? "failure" : "success", targ_res->new_val); return -EINVAL; } @@ -1314,19 +1290,10 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn, prog_name, relo_idx); /* calculate single target relo result explicitly */ - err = bpf_core_calc_relo(prog_name, relo, relo_idx, local_spec, NULL, &targ_res); + err = bpf_core_calc_relo(prog_name, relo, relo_idx, local_spec, NULL, targ_res); if (err) return err; } -patch_insn: - /* bpf_core_patch_insn() should know how to handle missing targ_spec */ - err = bpf_core_patch_insn(prog_name, insn, insn_idx, relo, relo_idx, &targ_res); - if (err) { - pr_warn("prog '%s': relo #%d: failed to patch insn #%u: %d\n", - prog_name, relo_idx, relo->insn_off / 8, err); - return -EINVAL; - } - return 0; } diff --git a/tools/lib/bpf/relo_core.h b/tools/lib/bpf/relo_core.h index 17799819ad7c..a28bf3711ce2 100644 --- a/tools/lib/bpf/relo_core.h +++ b/tools/lib/bpf/relo_core.h @@ -44,14 +44,44 @@ struct bpf_core_spec { __u32 bit_offset; }; -int bpf_core_apply_relo_insn(const char *prog_name, - struct bpf_insn *insn, int insn_idx, - const struct bpf_core_relo *relo, int relo_idx, - const struct btf *local_btf, - struct bpf_core_cand_list *cands, - struct bpf_core_spec *specs_scratch); +struct bpf_core_relo_res { + /* expected value in the instruction, unless validate == false */ + __u32 orig_val; + /* new value that needs to be patched up to */ + __u32 new_val; + /* relocation unsuccessful, poison instruction, but don't fail load */ + bool poison; + /* some relocations can't be validated against orig_val */ + bool validate; + /* for field byte offset relocations or the forms: + * *(T *)(rX + ) = rY + * rX = *(T *)(rY + ), + * we remember original and resolved field size to adjust direct + * memory loads of pointers and integers; this is necessary for 32-bit + * host kernel architectures, but also allows to automatically + * relocate fields that were resized from, e.g., u32 to u64, etc. + */ + bool fail_memsz_adjust; + __u32 orig_sz; + __u32 orig_type_id; + __u32 new_sz; + __u32 new_type_id; +}; + int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf, __u32 targ_id); size_t bpf_core_essential_name_len(const char *name); + +int bpf_core_calc_relo_insn(const char *prog_name, + const struct bpf_core_relo *relo, int relo_idx, + const struct btf *local_btf, + struct bpf_core_cand_list *cands, + struct bpf_core_spec *specs_scratch, + struct bpf_core_relo_res *targ_res); + +int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn, + int insn_idx, const struct bpf_core_relo *relo, + int relo_idx, const struct bpf_core_relo_res *res); + #endif diff --git a/tools/lib/bpf/skel_internal.h b/tools/lib/bpf/skel_internal.h index dcd3336512d4..bd6f4505e7b1 100644 --- a/tools/lib/bpf/skel_internal.h +++ b/tools/lib/bpf/skel_internal.h @@ -3,9 +3,19 @@ #ifndef __SKEL_INTERNAL_H #define __SKEL_INTERNAL_H +#ifdef __KERNEL__ +#include +#include +#include +#include +#include +#else #include #include #include +#include +#include "bpf.h" +#endif #ifndef __NR_bpf # if defined(__mips__) && defined(_ABIO32) @@ -25,24 +35,23 @@ * requested during loader program generation. */ struct bpf_map_desc { - union { - /* input for the loader prog */ - struct { - __aligned_u64 initial_value; - __u32 max_entries; - }; - /* output of the loader prog */ - struct { - int map_fd; - }; - }; + /* output of the loader prog */ + int map_fd; + /* input for the loader prog */ + __u32 max_entries; + __aligned_u64 initial_value; }; struct bpf_prog_desc { int prog_fd; }; +enum { + BPF_SKEL_KERNEL = (1ULL << 0), +}; + struct bpf_loader_ctx { - size_t sz; + __u32 sz; + __u32 flags; __u32 log_level; __u32 log_size; __u64 log_buf; @@ -57,12 +66,144 @@ struct bpf_load_and_run_opts { const char *errstr; }; +long bpf_sys_bpf(__u32 cmd, void *attr, __u32 attr_size); + static inline int skel_sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, unsigned int size) { +#ifdef __KERNEL__ + return bpf_sys_bpf(cmd, attr, size); +#else return syscall(__NR_bpf, cmd, attr, size); +#endif } +#ifdef __KERNEL__ +static inline int close(int fd) +{ + return close_fd(fd); +} + +static inline void *skel_alloc(size_t size) +{ + struct bpf_loader_ctx *ctx = kzalloc(size, GFP_KERNEL); + + if (!ctx) + return NULL; + ctx->flags |= BPF_SKEL_KERNEL; + return ctx; +} + +static inline void skel_free(const void *p) +{ + kfree(p); +} + +/* skel->bss/rodata maps are populated the following way: + * + * For kernel use: + * skel_prep_map_data() allocates kernel memory that kernel module can directly access. + * Generated lskel stores the pointer in skel->rodata and in skel->maps.rodata.initial_value. + * The loader program will perform probe_read_kernel() from maps.rodata.initial_value. + * skel_finalize_map_data() sets skel->rodata to point to actual value in a bpf map and + * does maps.rodata.initial_value = ~0ULL to signal skel_free_map_data() that kvfree + * is not nessary. + * + * For user space: + * skel_prep_map_data() mmaps anon memory into skel->rodata that can be accessed directly. + * Generated lskel stores the pointer in skel->rodata and in skel->maps.rodata.initial_value. + * The loader program will perform copy_from_user() from maps.rodata.initial_value. + * skel_finalize_map_data() remaps bpf array map value from the kernel memory into + * skel->rodata address. + * + * The "bpftool gen skeleton -L" command generates lskel.h that is suitable for + * both kernel and user space. The generated loader program does + * either bpf_probe_read_kernel() or bpf_copy_from_user() from initial_value + * depending on bpf_loader_ctx->flags. + */ +static inline void skel_free_map_data(void *p, __u64 addr, size_t sz) +{ + if (addr != ~0ULL) + kvfree(p); + /* When addr == ~0ULL the 'p' points to + * ((struct bpf_array *)map)->value. See skel_finalize_map_data. + */ +} + +static inline void *skel_prep_map_data(const void *val, size_t mmap_sz, size_t val_sz) +{ + void *addr; + + addr = kvmalloc(val_sz, GFP_KERNEL); + if (!addr) + return NULL; + memcpy(addr, val, val_sz); + return addr; +} + +static inline void *skel_finalize_map_data(__u64 *init_val, size_t mmap_sz, int flags, int fd) +{ + struct bpf_map *map; + void *addr = NULL; + + kvfree((void *) (long) *init_val); + *init_val = ~0ULL; + + /* At this point bpf_load_and_run() finished without error and + * 'fd' is a valid bpf map FD. All sanity checks below should succeed. + */ + map = bpf_map_get(fd); + if (IS_ERR(map)) + return NULL; + if (map->map_type != BPF_MAP_TYPE_ARRAY) + goto out; + addr = ((struct bpf_array *)map)->value; + /* the addr stays valid, since FD is not closed */ +out: + bpf_map_put(map); + return addr; +} + +#else + +static inline void *skel_alloc(size_t size) +{ + return calloc(1, size); +} + +static inline void skel_free(void *p) +{ + free(p); +} + +static inline void skel_free_map_data(void *p, __u64 addr, size_t sz) +{ + munmap(p, sz); +} + +static inline void *skel_prep_map_data(const void *val, size_t mmap_sz, size_t val_sz) +{ + void *addr; + + addr = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_ANONYMOUS, -1, 0); + if (addr == (void *) -1) + return NULL; + memcpy(addr, val, val_sz); + return addr; +} + +static inline void *skel_finalize_map_data(__u64 *init_val, size_t mmap_sz, int flags, int fd) +{ + void *addr; + + addr = mmap((void *) (long) *init_val, mmap_sz, flags, MAP_SHARED | MAP_FIXED, fd, 0); + if (addr == (void *) -1) + return NULL; + return addr; +} +#endif + static inline int skel_closenz(int fd) { if (fd > 0) @@ -136,22 +277,28 @@ static inline int skel_link_create(int prog_fd, int target_fd, return skel_sys_bpf(BPF_LINK_CREATE, &attr, attr_sz); } +#ifdef __KERNEL__ +#define set_err +#else +#define set_err err = -errno +#endif + static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts) { int map_fd = -1, prog_fd = -1, key = 0, err; union bpf_attr attr; - map_fd = skel_map_create(BPF_MAP_TYPE_ARRAY, "__loader.map", 4, opts->data_sz, 1); + err = map_fd = skel_map_create(BPF_MAP_TYPE_ARRAY, "__loader.map", 4, opts->data_sz, 1); if (map_fd < 0) { opts->errstr = "failed to create loader map"; - err = -errno; + set_err; goto out; } err = skel_map_update_elem(map_fd, &key, opts->data, 0); if (err < 0) { opts->errstr = "failed to update loader map"; - err = -errno; + set_err; goto out; } @@ -166,10 +313,10 @@ static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts) attr.log_size = opts->ctx->log_size; attr.log_buf = opts->ctx->log_buf; attr.prog_flags = BPF_F_SLEEPABLE; - prog_fd = skel_sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); + err = prog_fd = skel_sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); if (prog_fd < 0) { opts->errstr = "failed to load loader prog"; - err = -errno; + set_err; goto out; } @@ -181,10 +328,12 @@ static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts) if (err < 0 || (int)attr.test.retval < 0) { opts->errstr = "failed to execute loader prog"; if (err < 0) { - err = -errno; + set_err; } else { err = (int)attr.test.retval; +#ifndef __KERNEL__ errno = -err; +#endif } goto out; } diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c index 8b652f5ce423..ec823561b912 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf.c +++ b/tools/testing/selftests/bpf/prog_tests/btf.c @@ -6556,7 +6556,7 @@ static int test_get_linfo(const struct prog_info_raw_test *test, static void do_test_info_raw(unsigned int test_num) { const struct prog_info_raw_test *test = &info_raw_tests[test_num - 1]; - unsigned int raw_btf_size, linfo_str_off, linfo_size; + unsigned int raw_btf_size, linfo_str_off, linfo_size = 0; int btf_fd = -1, prog_fd = -1, err = 0; void *raw_btf, *patched_linfo = NULL; const char *ret_next_str; diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c index b8bdd1c3efca..8fbb40a832d5 100644 --- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c +++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c @@ -2,6 +2,7 @@ #include #include "progs/core_reloc_types.h" #include "bpf_testmod/bpf_testmod.h" +#include #include #include #include @@ -836,13 +837,27 @@ static size_t roundup_page(size_t sz) return (sz + page_size - 1) / page_size * page_size; } -void test_core_reloc(void) +static int run_btfgen(const char *src_btf, const char *dst_btf, const char *objpath) +{ + char command[4096]; + int n; + + n = snprintf(command, sizeof(command), + "./tools/build/bpftool/bpftool gen min_core_btf %s %s %s", + src_btf, dst_btf, objpath); + if (n < 0 || n >= sizeof(command)) + return -1; + + return system(command); +} + +static void run_core_reloc_tests(bool use_btfgen) { const size_t mmap_sz = roundup_page(sizeof(struct data)); DECLARE_LIBBPF_OPTS(bpf_object_open_opts, open_opts); struct core_reloc_test_case *test_case; const char *tp_name, *probe_name; - int err, i, equal; + int err, i, equal, fd; struct bpf_link *link = NULL; struct bpf_map *data_map; struct bpf_program *prog; @@ -854,6 +869,7 @@ void test_core_reloc(void) my_pid_tgid = getpid() | ((uint64_t)syscall(SYS_gettid) << 32); for (i = 0; i < ARRAY_SIZE(test_cases); i++) { + char btf_file[] = "/tmp/core_reloc.btf.XXXXXX"; test_case = &test_cases[i]; if (!test__start_subtest(test_case->case_name)) continue; @@ -863,6 +879,25 @@ void test_core_reloc(void) continue; } + /* generate a "minimal" BTF file and use it as source */ + if (use_btfgen) { + if (!test_case->btf_src_file || test_case->fails) { + test__skip(); + continue; + } + + fd = mkstemp(btf_file); + if (!ASSERT_GE(fd, 0, "btf_tmp")) + continue; + close(fd); /* we only need the path */ + err = run_btfgen(test_case->btf_src_file, btf_file, + test_case->bpf_obj_file); + if (!ASSERT_OK(err, "run_btfgen")) + continue; + + test_case->btf_src_file = btf_file; + } + if (test_case->setup) { err = test_case->setup(test_case); if (CHECK(err, "test_setup", "test #%d setup failed: %d\n", i, err)) @@ -872,7 +907,7 @@ void test_core_reloc(void) if (test_case->btf_src_file) { err = access(test_case->btf_src_file, R_OK); if (!ASSERT_OK(err, "btf_src_file")) - goto cleanup; + continue; } open_opts.btf_custom_path = test_case->btf_src_file; @@ -954,8 +989,19 @@ void test_core_reloc(void) CHECK_FAIL(munmap(mmap_data, mmap_sz)); mmap_data = NULL; } + remove(btf_file); bpf_link__destroy(link); link = NULL; bpf_object__close(obj); } } + +void test_core_reloc(void) +{ + run_core_reloc_tests(false); +} + +void test_core_btfgen(void) +{ + run_core_reloc_tests(true); +} diff --git a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c index c2426df58e17..647b0a833628 100644 --- a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c +++ b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c @@ -140,7 +140,7 @@ static struct nstoken *open_netns(const char *name) int err; struct nstoken *token; - token = malloc(sizeof(struct nstoken)); + token = calloc(1, sizeof(struct nstoken)); if (!ASSERT_OK_PTR(token, "malloc token")) return NULL; diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c index d18e6f343c48..2f033da4cd45 100644 --- a/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c +++ b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c @@ -5,11 +5,12 @@ static void test_xdp_update_frags(void) { const char *file = "./test_xdp_update_frags.o"; + int err, prog_fd, max_skb_frags, buf_size, num; struct bpf_program *prog; struct bpf_object *obj; - int err, prog_fd; __u32 *offset; __u8 *buf; + FILE *f; LIBBPF_OPTS(bpf_test_run_opts, topts); obj = bpf_object__open(file); @@ -99,6 +100,41 @@ static void test_xdp_update_frags(void) ASSERT_EQ(buf[7621], 0xbb, "xdp_update_frag buf[7621]"); free(buf); + + /* test_xdp_update_frags: unsupported buffer size */ + f = fopen("/proc/sys/net/core/max_skb_frags", "r"); + if (!ASSERT_OK_PTR(f, "max_skb_frag file pointer")) + goto out; + + num = fscanf(f, "%d", &max_skb_frags); + fclose(f); + + if (!ASSERT_EQ(num, 1, "max_skb_frags read failed")) + goto out; + + /* xdp_buff linear area size is always set to 4096 in the + * bpf_prog_test_run_xdp routine. + */ + buf_size = 4096 + (max_skb_frags + 1) * sysconf(_SC_PAGE_SIZE); + buf = malloc(buf_size); + if (!ASSERT_OK_PTR(buf, "alloc buf")) + goto out; + + memset(buf, 0, buf_size); + offset = (__u32 *)buf; + *offset = 16; + buf[*offset] = 0xaa; + buf[*offset + 15] = 0xaa; + + topts.data_in = buf; + topts.data_out = buf; + topts.data_size_in = buf_size; + topts.data_size_out = buf_size; + + err = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_EQ(err, -ENOMEM, + "unsupported buf size, possible non-default /proc/sys/net/core/max_skb_flags?"); + free(buf); out: bpf_object__close(obj); } diff --git a/tools/testing/selftests/bpf/test_cpp.cpp b/tools/testing/selftests/bpf/test_cpp.cpp index e00201de2890..773f165c4898 100644 --- a/tools/testing/selftests/bpf/test_cpp.cpp +++ b/tools/testing/selftests/bpf/test_cpp.cpp @@ -5,18 +5,100 @@ #include #include "test_core_extern.skel.h" -/* do nothing, just make sure we can link successfully */ +template +class Skeleton { +private: + T *skel; +public: + Skeleton(): skel(nullptr) { } + + ~Skeleton() { if (skel) T::destroy(skel); } + + int open(const struct bpf_object_open_opts *opts = nullptr) + { + int err; + + if (skel) + return -EBUSY; + + skel = T::open(opts); + err = libbpf_get_error(skel); + if (err) { + skel = nullptr; + return err; + } + + return 0; + } + + int load() { return T::load(skel); } + + int attach() { return T::attach(skel); } + + void detach() { return T::detach(skel); } + + const T* operator->() const { return skel; } + + T* operator->() { return skel; } + + const T *get() const { return skel; } +}; static void dump_printf(void *ctx, const char *fmt, va_list args) { } +static void try_skeleton_template() +{ + Skeleton skel; + std::string prog_name; + int err; + LIBBPF_OPTS(bpf_object_open_opts, opts); + + err = skel.open(&opts); + if (err) { + fprintf(stderr, "Skeleton open failed: %d\n", err); + return; + } + + skel->data->kern_ver = 123; + skel->data->int_val = skel->data->ushort_val; + + err = skel.load(); + if (err) { + fprintf(stderr, "Skeleton load failed: %d\n", err); + return; + } + + if (!skel->kconfig->CONFIG_BPF_SYSCALL) + fprintf(stderr, "Seems like CONFIG_BPF_SYSCALL isn't set?!\n"); + + err = skel.attach(); + if (err) { + fprintf(stderr, "Skeleton attach failed: %d\n", err); + return; + } + + prog_name = bpf_program__name(skel->progs.handle_sys_enter); + if (prog_name != "handle_sys_enter") + fprintf(stderr, "Unexpected program name: %s\n", prog_name.c_str()); + + bpf_link__destroy(skel->links.handle_sys_enter); + skel->links.handle_sys_enter = bpf_program__attach(skel->progs.handle_sys_enter); + + skel.detach(); + + /* destructor will destory underlying skeleton */ +} + int main(int argc, char *argv[]) { struct btf_dump_opts opts = { }; struct test_core_extern *skel; struct btf *btf; + try_skeleton_template(); + /* libbpf.h */ libbpf_set_print(NULL); @@ -25,7 +107,8 @@ int main(int argc, char *argv[]) /* btf.h */ btf = btf__new(NULL, 0); - btf_dump__new(btf, dump_printf, nullptr, &opts); + if (!libbpf_get_error(btf)) + btf_dump__new(btf, dump_printf, nullptr, &opts); /* BPF skeleton */ skel = test_core_extern__open_and_load(); diff --git a/tools/testing/selftests/bpf/vmtest.sh b/tools/testing/selftests/bpf/vmtest.sh index b3afd43549fa..e0bb04a97e10 100755 --- a/tools/testing/selftests/bpf/vmtest.sh +++ b/tools/testing/selftests/bpf/vmtest.sh @@ -241,7 +241,7 @@ EOF -nodefaults \ -display none \ -serial mon:stdio \ - "${qemu_flags[@]}" \ + "${QEMU_FLAGS[@]}" \ -enable-kvm \ -m 4G \ -drive file="${rootfs_img}",format=raw,index=1,media=disk,if=virtio,cache=none \