Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 910 insertions, 0 deletions

diff --git a/tools/bpf/resolve_btfids/.gitignore b/tools/bpf/resolve_btfids/.gitignore
new file mode 100644
index 000000000..16913fffc
--- /dev/null
+++ b/tools/bpf/resolve_btfids/.gitignore
@@ -0,0 +1,3 @@
+/fixdep
+/resolve_btfids
+/libbpf/
diff --git a/tools/bpf/resolve_btfids/Build b/tools/bpf/resolve_btfids/Build
new file mode 100644
index 000000000..077de3829
--- /dev/null
+++ b/tools/bpf/resolve_btfids/Build
@@ -0,0 +1,12 @@
+hostprogs := resolve_btfids
+
+resolve_btfids-y += main.o
+resolve_btfids-y += rbtree.o
+resolve_btfids-y += zalloc.o
+resolve_btfids-y += string.o
+resolve_btfids-y += ctype.o
+resolve_btfids-y += str_error_r.o
+
+$(OUTPUT)%.o: ../../lib/%.c FORCE
+	$(call rule_mkdir)
+	$(call if_changed_dep,host_cc_o_c)
diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
new file mode 100644
index 000000000..4b8079f29
--- /dev/null
+++ b/tools/bpf/resolve_btfids/Makefile
@@ -0,0 +1,112 @@
+# SPDX-License-Identifier: GPL-2.0-only
+include ../../scripts/Makefile.include
+include ../../scripts/Makefile.arch
+
+srctree := $(abspath $(CURDIR)/../../../)
+
+ifeq ($(V),1)
+  Q =
+  msg =
+else
+  Q = @
+  ifeq ($(silent),1)
+    msg =
+  else
+    msg = @printf '  %-8s %s%s\n' "$(1)" "$(notdir $(2))" "$(if $(3), $(3))";
+  endif
+  MAKEFLAGS=--no-print-directory
+endif
+
+# Overrides for the prepare step libraries.
+HOST_OVERRIDES := AR="$(HOSTAR)" CC="$(HOSTCC)" LD="$(HOSTLD)" ARCH="$(HOSTARCH)" \
+		  CROSS_COMPILE="" EXTRA_CFLAGS="$(HOSTCFLAGS)"
+
+RM      ?= rm
+HOSTCC  ?= gcc
+HOSTLD  ?= ld
+HOSTAR  ?= ar
+CROSS_COMPILE =
+
+OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/
+
+LIBBPF_SRC := $(srctree)/tools/lib/bpf/
+SUBCMD_SRC := $(srctree)/tools/lib/subcmd/
+
+BPFOBJ     := $(OUTPUT)/libbpf/libbpf.a
+LIBBPF_OUT := $(abspath $(dir $(BPFOBJ)))/
+SUBCMDOBJ  := $(OUTPUT)/libsubcmd/libsubcmd.a
+SUBCMD_OUT := $(abspath $(dir $(SUBCMDOBJ)))/
+
+LIBBPF_DESTDIR := $(LIBBPF_OUT)
+LIBBPF_INCLUDE := $(LIBBPF_DESTDIR)include
+
+SUBCMD_DESTDIR := $(SUBCMD_OUT)
+SUBCMD_INCLUDE := $(SUBCMD_DESTDIR)include
+
+BINARY     := $(OUTPUT)/resolve_btfids
+BINARY_IN  := $(BINARY)-in.o
+
+all: $(BINARY)
+
+prepare: $(BPFOBJ) $(SUBCMDOBJ)
+
+$(OUTPUT) $(OUTPUT)/libsubcmd $(LIBBPF_OUT):
+	$(call msg,MKDIR,,$@)
+	$(Q)mkdir -p $(@)
+
+$(SUBCMDOBJ): fixdep FORCE | $(OUTPUT)/libsubcmd
+	$(Q)$(MAKE) -C $(SUBCMD_SRC) OUTPUT=$(SUBCMD_OUT) \
+		    DESTDIR=$(SUBCMD_DESTDIR) $(HOST_OVERRIDES) prefix= subdir= \
+		    $(abspath $@) install_headers
+
+$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OUT)
+	$(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) OUTPUT=$(LIBBPF_OUT)    \
+		    DESTDIR=$(LIBBPF_DESTDIR) $(HOST_OVERRIDES) prefix= subdir= \
+		    $(abspath $@) install_headers
+
+LIBELF_FLAGS := $(shell $(HOSTPKG_CONFIG) libelf --cflags 2>/dev/null)
+LIBELF_LIBS  := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf)
+
+HOSTCFLAGS_resolve_btfids += -g \
+          -I$(srctree)/tools/include \
+          -I$(srctree)/tools/include/uapi \
+          -I$(LIBBPF_INCLUDE) \
+          -I$(SUBCMD_INCLUDE) \
+          $(LIBELF_FLAGS)
+
+LIBS = $(LIBELF_LIBS) -lz
+
+export srctree OUTPUT HOSTCFLAGS_resolve_btfids Q HOSTCC HOSTLD HOSTAR
+include $(srctree)/tools/build/Makefile.include
+
+$(BINARY_IN): fixdep FORCE prepare | $(OUTPUT)
+	$(Q)$(MAKE) $(build)=resolve_btfids
+
+$(BINARY): $(BPFOBJ) $(SUBCMDOBJ) $(BINARY_IN)
+	$(call msg,LINK,$@)
+	$(Q)$(HOSTCC) $(BINARY_IN) $(KBUILD_HOSTLDFLAGS) -o $@ $(BPFOBJ) $(SUBCMDOBJ) $(LIBS)
+
+clean_objects := $(wildcard $(OUTPUT)/*.o                \
+                            $(OUTPUT)/.*.o.cmd           \
+                            $(OUTPUT)/.*.o.d             \
+                            $(LIBBPF_OUT)                \
+                            $(LIBBPF_DESTDIR)            \
+                            $(SUBCMD_OUT)                \
+                            $(SUBCMD_DESTDIR)            \
+                            $(OUTPUT)/resolve_btfids)
+
+ifneq ($(clean_objects),)
+clean: fixdep-clean
+	$(call msg,CLEAN,$(BINARY))
+	$(Q)$(RM) -rf $(clean_objects)
+else
+clean:
+endif
+
+tags:
+	$(call msg,GEN,,tags)
+	$(Q)ctags -R . $(LIBBPF_SRC) $(SUBCMD_SRC)
+
+FORCE:
+
+.PHONY: all FORCE clean tags prepare
diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
new file mode 100644
index 000000000..770581740
--- /dev/null
+++ b/tools/bpf/resolve_btfids/main.c
@@ -0,0 +1,783 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+
+/*
+ * resolve_btfids scans Elf object for .BTF_ids section and resolves
+ * its symbols with BTF ID values.
+ *
+ * Each symbol points to 4 bytes data and is expected to have
+ * following name syntax:
+ *
+ * __BTF_ID__<type>__<symbol>[__<id>]
+ *
+ * type is:
+ *
+ *   func    - lookup BTF_KIND_FUNC symbol with <symbol> name
+ *             and store its ID into the data:
+ *
+ *             __BTF_ID__func__vfs_close__1:
+ *             .zero 4
+ *
+ *   struct  - lookup BTF_KIND_STRUCT symbol with <symbol> name
+ *             and store its ID into the data:
+ *
+ *             __BTF_ID__struct__sk_buff__1:
+ *             .zero 4
+ *
+ *   union   - lookup BTF_KIND_UNION symbol with <symbol> name
+ *             and store its ID into the data:
+ *
+ *             __BTF_ID__union__thread_union__1:
+ *             .zero 4
+ *
+ *   typedef - lookup BTF_KIND_TYPEDEF symbol with <symbol> name
+ *             and store its ID into the data:
+ *
+ *             __BTF_ID__typedef__pid_t__1:
+ *             .zero 4
+ *
+ *   set     - store symbol size into first 4 bytes and sort following
+ *             ID list
+ *
+ *             __BTF_ID__set__list:
+ *             .zero 4
+ *             list:
+ *             __BTF_ID__func__vfs_getattr__3:
+ *             .zero 4
+ *             __BTF_ID__func__vfs_fallocate__4:
+ *             .zero 4
+ *
+ *   set8    - store symbol size into first 4 bytes and sort following
+ *             ID list
+ *
+ *             __BTF_ID__set8__list:
+ *             .zero 8
+ *             list:
+ *             __BTF_ID__func__vfs_getattr__3:
+ *             .zero 4
+ *	       .word (1 << 0) | (1 << 2)
+ *             __BTF_ID__func__vfs_fallocate__5:
+ *             .zero 4
+ *	       .word (1 << 3) | (1 << 1) | (1 << 2)
+ */
+
+#define  _GNU_SOURCE
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <libelf.h>
+#include <gelf.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <linux/rbtree.h>
+#include <linux/zalloc.h>
+#include <linux/err.h>
+#include <bpf/btf.h>
+#include <bpf/libbpf.h>
+#include <subcmd/parse-options.h>
+
+#define BTF_IDS_SECTION	".BTF_ids"
+#define BTF_ID		"__BTF_ID__"
+
+#define BTF_STRUCT	"struct"
+#define BTF_UNION	"union"
+#define BTF_TYPEDEF	"typedef"
+#define BTF_FUNC	"func"
+#define BTF_SET		"set"
+#define BTF_SET8	"set8"
+
+#define ADDR_CNT	100
+
+struct btf_id {
+	struct rb_node	 rb_node;
+	char		*name;
+	union {
+		int	 id;
+		int	 cnt;
+	};
+	int		 addr_cnt;
+	bool		 is_set;
+	bool		 is_set8;
+	Elf64_Addr	 addr[ADDR_CNT];
+};
+
+struct object {
+	const char *path;
+	const char *btf;
+	const char *base_btf_path;
+
+	struct {
+		int		 fd;
+		Elf		*elf;
+		Elf_Data	*symbols;
+		Elf_Data	*idlist;
+		int		 symbols_shndx;
+		int		 idlist_shndx;
+		size_t		 strtabidx;
+		unsigned long	 idlist_addr;
+	} efile;
+
+	struct rb_root	sets;
+	struct rb_root	structs;
+	struct rb_root	unions;
+	struct rb_root	typedefs;
+	struct rb_root	funcs;
+
+	int nr_funcs;
+	int nr_structs;
+	int nr_unions;
+	int nr_typedefs;
+};
+
+static int verbose;
+
+static int eprintf(int level, int var, const char *fmt, ...)
+{
+	va_list args;
+	int ret = 0;
+
+	if (var >= level) {
+		va_start(args, fmt);
+		ret = vfprintf(stderr, fmt, args);
+		va_end(args);
+	}
+	return ret;
+}
+
+#ifndef pr_fmt
+#define pr_fmt(fmt) fmt
+#endif
+
+#define pr_debug(fmt, ...) \
+	eprintf(1, verbose, pr_fmt(fmt), ##__VA_ARGS__)
+#define pr_debugN(n, fmt, ...) \
+	eprintf(n, verbose, pr_fmt(fmt), ##__VA_ARGS__)
+#define pr_debug2(fmt, ...) pr_debugN(2, pr_fmt(fmt), ##__VA_ARGS__)
+#define pr_err(fmt, ...) \
+	eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__)
+#define pr_info(fmt, ...) \
+	eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__)
+
+static bool is_btf_id(const char *name)
+{
+	return name && !strncmp(name, BTF_ID, sizeof(BTF_ID) - 1);
+}
+
+static struct btf_id *btf_id__find(struct rb_root *root, const char *name)
+{
+	struct rb_node *p = root->rb_node;
+	struct btf_id *id;
+	int cmp;
+
+	while (p) {
+		id = rb_entry(p, struct btf_id, rb_node);
+		cmp = strcmp(id->name, name);
+		if (cmp < 0)
+			p = p->rb_left;
+		else if (cmp > 0)
+			p = p->rb_right;
+		else
+			return id;
+	}
+	return NULL;
+}
+
+static struct btf_id *
+btf_id__add(struct rb_root *root, char *name, bool unique)
+{
+	struct rb_node **p = &root->rb_node;
+	struct rb_node *parent = NULL;
+	struct btf_id *id;
+	int cmp;
+
+	while (*p != NULL) {
+		parent = *p;
+		id = rb_entry(parent, struct btf_id, rb_node);
+		cmp = strcmp(id->name, name);
+		if (cmp < 0)
+			p = &(*p)->rb_left;
+		else if (cmp > 0)
+			p = &(*p)->rb_right;
+		else
+			return unique ? NULL : id;
+	}
+
+	id = zalloc(sizeof(*id));
+	if (id) {
+		pr_debug("adding symbol %s\n", name);
+		id->name = name;
+		rb_link_node(&id->rb_node, parent, p);
+		rb_insert_color(&id->rb_node, root);
+	}
+	return id;
+}
+
+static char *get_id(const char *prefix_end)
+{
+	/*
+	 * __BTF_ID__func__vfs_truncate__0
+	 * prefix_end =  ^
+	 * pos        =    ^
+	 */
+	int len = strlen(prefix_end);
+	int pos = sizeof("__") - 1;
+	char *p, *id;
+
+	if (pos >= len)
+		return NULL;
+
+	id = strdup(prefix_end + pos);
+	if (id) {
+		/*
+		 * __BTF_ID__func__vfs_truncate__0
+		 * id =            ^
+		 *
+		 * cut the unique id part
+		 */
+		p = strrchr(id, '_');
+		p--;
+		if (*p != '_') {
+			free(id);
+			return NULL;
+		}
+		*p = '\0';
+	}
+	return id;
+}
+
+static struct btf_id *add_set(struct object *obj, char *name, bool is_set8)
+{
+	/*
+	 * __BTF_ID__set__name
+	 * name =    ^
+	 * id   =         ^
+	 */
+	char *id = name + (is_set8 ? sizeof(BTF_SET8 "__") : sizeof(BTF_SET "__")) - 1;
+	int len = strlen(name);
+
+	if (id >= name + len) {
+		pr_err("FAILED to parse set name: %s\n", name);
+		return NULL;
+	}
+
+	return btf_id__add(&obj->sets, id, true);
+}
+
+static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
+{
+	char *id;
+
+	id = get_id(name + size);
+	if (!id) {
+		pr_err("FAILED to parse symbol name: %s\n", name);
+		return NULL;
+	}
+
+	return btf_id__add(root, id, false);
+}
+
+/* Older libelf.h and glibc elf.h might not yet define the ELF compression types. */
+#ifndef SHF_COMPRESSED
+#define SHF_COMPRESSED (1 << 11) /* Section with compressed data. */
+#endif
+
+/*
+ * The data of compressed section should be aligned to 4
+ * (for 32bit) or 8 (for 64 bit) bytes. The binutils ld
+ * sets sh_addralign to 1, which makes libelf fail with
+ * misaligned section error during the update:
+ *    FAILED elf_update(WRITE): invalid section alignment
+ *
+ * While waiting for ld fix, we fix the compressed sections
+ * sh_addralign value manualy.
+ */
+static int compressed_section_fix(Elf *elf, Elf_Scn *scn, GElf_Shdr *sh)
+{
+	int expected = gelf_getclass(elf) == ELFCLASS32 ? 4 : 8;
+
+	if (!(sh->sh_flags & SHF_COMPRESSED))
+		return 0;
+
+	if (sh->sh_addralign == expected)
+		return 0;
+
+	pr_debug2(" - fixing wrong alignment sh_addralign %u, expected %u\n",
+		  sh->sh_addralign, expected);
+
+	sh->sh_addralign = expected;
+
+	if (gelf_update_shdr(scn, sh) == 0) {
+		pr_err("FAILED cannot update section header: %s\n",
+			elf_errmsg(-1));
+		return -1;
+	}
+	return 0;
+}
+
+static int elf_collect(struct object *obj)
+{
+	Elf_Scn *scn = NULL;
+	size_t shdrstrndx;
+	int idx = 0;
+	Elf *elf;
+	int fd;
+
+	fd = open(obj->path, O_RDWR, 0666);
+	if (fd == -1) {
+		pr_err("FAILED cannot open %s: %s\n",
+			obj->path, strerror(errno));
+		return -1;
+	}
+
+	elf_version(EV_CURRENT);
+
+	elf = elf_begin(fd, ELF_C_RDWR_MMAP, NULL);
+	if (!elf) {
+		close(fd);
+		pr_err("FAILED cannot create ELF descriptor: %s\n",
+			elf_errmsg(-1));
+		return -1;
+	}
+
+	obj->efile.fd  = fd;
+	obj->efile.elf = elf;
+
+	elf_flagelf(elf, ELF_C_SET, ELF_F_LAYOUT);
+
+	if (elf_getshdrstrndx(elf, &shdrstrndx) != 0) {
+		pr_err("FAILED cannot get shdr str ndx\n");
+		return -1;
+	}
+
+	/*
+	 * Scan all the elf sections and look for save data
+	 * from .BTF_ids section and symbols.
+	 */
+	while ((scn = elf_nextscn(elf, scn)) != NULL) {
+		Elf_Data *data;
+		GElf_Shdr sh;
+		char *name;
+
+		idx++;
+		if (gelf_getshdr(scn, &sh) != &sh) {
+			pr_err("FAILED get section(%d) header\n", idx);
+			return -1;
+		}
+
+		name = elf_strptr(elf, shdrstrndx, sh.sh_name);
+		if (!name) {
+			pr_err("FAILED get section(%d) name\n", idx);
+			return -1;
+		}
+
+		data = elf_getdata(scn, 0);
+		if (!data) {
+			pr_err("FAILED to get section(%d) data from %s\n",
+				idx, name);
+			return -1;
+		}
+
+		pr_debug2("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n",
+			  idx, name, (unsigned long) data->d_size,
+			  (int) sh.sh_link, (unsigned long) sh.sh_flags,
+			  (int) sh.sh_type);
+
+		if (sh.sh_type == SHT_SYMTAB) {
+			obj->efile.symbols       = data;
+			obj->efile.symbols_shndx = idx;
+			obj->efile.strtabidx     = sh.sh_link;
+		} else if (!strcmp(name, BTF_IDS_SECTION)) {
+			obj->efile.idlist       = data;
+			obj->efile.idlist_shndx = idx;
+			obj->efile.idlist_addr  = sh.sh_addr;
+		}
+
+		if (compressed_section_fix(elf, scn, &sh))
+			return -1;
+	}
+
+	return 0;
+}
+
+static int symbols_collect(struct object *obj)
+{
+	Elf_Scn *scn = NULL;
+	int n, i;
+	GElf_Shdr sh;
+	char *name;
+
+	scn = elf_getscn(obj->efile.elf, obj->efile.symbols_shndx);
+	if (!scn)
+		return -1;
+
+	if (gelf_getshdr(scn, &sh) != &sh)
+		return -1;
+
+	n = sh.sh_size / sh.sh_entsize;
+
+	/*
+	 * Scan symbols and look for the ones starting with
+	 * __BTF_ID__* over .BTF_ids section.
+	 */
+	for (i = 0; i < n; i++) {
+		char *prefix;
+		struct btf_id *id;
+		GElf_Sym sym;
+
+		if (!gelf_getsym(obj->efile.symbols, i, &sym))
+			return -1;
+
+		if (sym.st_shndx != obj->efile.idlist_shndx)
+			continue;
+
+		name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
+				  sym.st_name);
+
+		if (!is_btf_id(name))
+			continue;
+
+		/*
+		 * __BTF_ID__TYPE__vfs_truncate__0
+		 * prefix =  ^
+		 */
+		prefix = name + sizeof(BTF_ID) - 1;
+
+		/* struct */
+		if (!strncmp(prefix, BTF_STRUCT, sizeof(BTF_STRUCT) - 1)) {
+			obj->nr_structs++;
+			id = add_symbol(&obj->structs, prefix, sizeof(BTF_STRUCT) - 1);
+		/* union  */
+		} else if (!strncmp(prefix, BTF_UNION, sizeof(BTF_UNION) - 1)) {
+			obj->nr_unions++;
+			id = add_symbol(&obj->unions, prefix, sizeof(BTF_UNION) - 1);
+		/* typedef */
+		} else if (!strncmp(prefix, BTF_TYPEDEF, sizeof(BTF_TYPEDEF) - 1)) {
+			obj->nr_typedefs++;
+			id = add_symbol(&obj->typedefs, prefix, sizeof(BTF_TYPEDEF) - 1);
+		/* func */
+		} else if (!strncmp(prefix, BTF_FUNC, sizeof(BTF_FUNC) - 1)) {
+			obj->nr_funcs++;
+			id = add_symbol(&obj->funcs, prefix, sizeof(BTF_FUNC) - 1);
+		/* set8 */
+		} else if (!strncmp(prefix, BTF_SET8, sizeof(BTF_SET8) - 1)) {
+			id = add_set(obj, prefix, true);
+			/*
+			 * SET8 objects store list's count, which is encoded
+			 * in symbol's size, together with 'cnt' field hence
+			 * that - 1.
+			 */
+			if (id) {
+				id->cnt = sym.st_size / sizeof(uint64_t) - 1;
+				id->is_set8 = true;
+			}
+		/* set */
+		} else if (!strncmp(prefix, BTF_SET, sizeof(BTF_SET) - 1)) {
+			id = add_set(obj, prefix, false);
+			/*
+			 * SET objects store list's count, which is encoded
+			 * in symbol's size, together with 'cnt' field hence
+			 * that - 1.
+			 */
+			if (id) {
+				id->cnt = sym.st_size / sizeof(int) - 1;
+				id->is_set = true;
+			}
+		} else {
+			pr_err("FAILED unsupported prefix %s\n", prefix);
+			return -1;
+		}
+
+		if (!id)
+			return -ENOMEM;
+
+		if (id->addr_cnt >= ADDR_CNT) {
+			pr_err("FAILED symbol %s crossed the number of allowed lists\n",
+				id->name);
+			return -1;
+		}
+		id->addr[id->addr_cnt++] = sym.st_value;
+	}
+
+	return 0;
+}
+
+static int symbols_resolve(struct object *obj)
+{
+	int nr_typedefs = obj->nr_typedefs;
+	int nr_structs  = obj->nr_structs;
+	int nr_unions   = obj->nr_unions;
+	int nr_funcs    = obj->nr_funcs;
+	struct btf *base_btf = NULL;
+	int err, type_id;
+	struct btf *btf;
+	__u32 nr_types;
+
+	if (obj->base_btf_path) {
+		base_btf = btf__parse(obj->base_btf_path, NULL);
+		err = libbpf_get_error(base_btf);
+		if (err) {
+			pr_err("FAILED: load base BTF from %s: %s\n",
+			       obj->base_btf_path, strerror(-err));
+			return -1;
+		}
+	}
+
+	btf = btf__parse_split(obj->btf ?: obj->path, base_btf);
+	err = libbpf_get_error(btf);
+	if (err) {
+		pr_err("FAILED: load BTF from %s: %s\n",
+			obj->btf ?: obj->path, strerror(-err));
+		goto out;
+	}
+
+	err = -1;
+	nr_types = btf__type_cnt(btf);
+
+	/*
+	 * Iterate all the BTF types and search for collected symbol IDs.
+	 */
+	for (type_id = 1; type_id < nr_types; type_id++) {
+		const struct btf_type *type;
+		struct rb_root *root;
+		struct btf_id *id;
+		const char *str;
+		int *nr;
+
+		type = btf__type_by_id(btf, type_id);
+		if (!type) {
+			pr_err("FAILED: malformed BTF, can't resolve type for ID %d\n",
+				type_id);
+			goto out;
+		}
+
+		if (btf_is_func(type) && nr_funcs) {
+			nr   = &nr_funcs;
+			root = &obj->funcs;
+		} else if (btf_is_struct(type) && nr_structs) {
+			nr   = &nr_structs;
+			root = &obj->structs;
+		} else if (btf_is_union(type) && nr_unions) {
+			nr   = &nr_unions;
+			root = &obj->unions;
+		} else if (btf_is_typedef(type) && nr_typedefs) {
+			nr   = &nr_typedefs;
+			root = &obj->typedefs;
+		} else
+			continue;
+
+		str = btf__name_by_offset(btf, type->name_off);
+		if (!str) {
+			pr_err("FAILED: malformed BTF, can't resolve name for ID %d\n",
+				type_id);
+			goto out;
+		}
+
+		id = btf_id__find(root, str);
+		if (id) {
+			if (id->id) {
+				pr_info("WARN: multiple IDs found for '%s': %d, %d - using %d\n",
+					str, id->id, type_id, id->id);
+			} else {
+				id->id = type_id;
+				(*nr)--;
+			}
+		}
+	}
+
+	err = 0;
+out:
+	btf__free(base_btf);
+	btf__free(btf);
+	return err;
+}
+
+static int id_patch(struct object *obj, struct btf_id *id)
+{
+	Elf_Data *data = obj->efile.idlist;
+	int *ptr = data->d_buf;
+	int i;
+
+	/* For set, set8, id->id may be 0 */
+	if (!id->id && !id->is_set && !id->is_set8)
+		pr_err("WARN: resolve_btfids: unresolved symbol %s\n", id->name);
+
+	for (i = 0; i < id->addr_cnt; i++) {
+		unsigned long addr = id->addr[i];
+		unsigned long idx = addr - obj->efile.idlist_addr;
+
+		pr_debug("patching addr %5lu: ID %7d [%s]\n",
+			 idx, id->id, id->name);
+
+		if (idx >= data->d_size) {
+			pr_err("FAILED patching index %lu out of bounds %lu\n",
+				idx, data->d_size);
+			return -1;
+		}
+
+		idx = idx / sizeof(int);
+		ptr[idx] = id->id;
+	}
+
+	return 0;
+}
+
+static int __symbols_patch(struct object *obj, struct rb_root *root)
+{
+	struct rb_node *next;
+	struct btf_id *id;
+
+	next = rb_first(root);
+	while (next) {
+		id = rb_entry(next, struct btf_id, rb_node);
+
+		if (id_patch(obj, id))
+			return -1;
+
+		next = rb_next(next);
+	}
+	return 0;
+}
+
+static int cmp_id(const void *pa, const void *pb)
+{
+	const int *a = pa, *b = pb;
+
+	return *a - *b;
+}
+
+static int sets_patch(struct object *obj)
+{
+	Elf_Data *data = obj->efile.idlist;
+	int *ptr = data->d_buf;
+	struct rb_node *next;
+
+	next = rb_first(&obj->sets);
+	while (next) {
+		unsigned long addr, idx;
+		struct btf_id *id;
+		int *base;
+		int cnt;
+
+		id   = rb_entry(next, struct btf_id, rb_node);
+		addr = id->addr[0];
+		idx  = addr - obj->efile.idlist_addr;
+
+		/* sets are unique */
+		if (id->addr_cnt != 1) {
+			pr_err("FAILED malformed data for set '%s'\n",
+				id->name);
+			return -1;
+		}
+
+		idx = idx / sizeof(int);
+		base = &ptr[idx] + (id->is_set8 ? 2 : 1);
+		cnt = ptr[idx];
+
+		pr_debug("sorting  addr %5lu: cnt %6d [%s]\n",
+			 (idx + 1) * sizeof(int), cnt, id->name);
+
+		qsort(base, cnt, id->is_set8 ? sizeof(uint64_t) : sizeof(int), cmp_id);
+
+		next = rb_next(next);
+	}
+	return 0;
+}
+
+static int symbols_patch(struct object *obj)
+{
+	int err;
+
+	if (__symbols_patch(obj, &obj->structs)  ||
+	    __symbols_patch(obj, &obj->unions)   ||
+	    __symbols_patch(obj, &obj->typedefs) ||
+	    __symbols_patch(obj, &obj->funcs)    ||
+	    __symbols_patch(obj, &obj->sets))
+		return -1;
+
+	if (sets_patch(obj))
+		return -1;
+
+	/* Set type to ensure endian translation occurs. */
+	obj->efile.idlist->d_type = ELF_T_WORD;
+
+	elf_flagdata(obj->efile.idlist, ELF_C_SET, ELF_F_DIRTY);
+
+	err = elf_update(obj->efile.elf, ELF_C_WRITE);
+	if (err < 0) {
+		pr_err("FAILED elf_update(WRITE): %s\n",
+			elf_errmsg(-1));
+	}
+
+	pr_debug("update %s for %s\n",
+		 err >= 0 ? "ok" : "failed", obj->path);
+	return err < 0 ? -1 : 0;
+}
+
+static const char * const resolve_btfids_usage[] = {
+	"resolve_btfids [<options>] <ELF object>",
+	NULL
+};
+
+int main(int argc, const char **argv)
+{
+	struct object obj = {
+		.efile = {
+			.idlist_shndx  = -1,
+			.symbols_shndx = -1,
+		},
+		.structs  = RB_ROOT,
+		.unions   = RB_ROOT,
+		.typedefs = RB_ROOT,
+		.funcs    = RB_ROOT,
+		.sets     = RB_ROOT,
+	};
+	struct option btfid_options[] = {
+		OPT_INCR('v', "verbose", &verbose,
+			 "be more verbose (show errors, etc)"),
+		OPT_STRING(0, "btf", &obj.btf, "BTF data",
+			   "BTF data"),
+		OPT_STRING('b', "btf_base", &obj.base_btf_path, "file",
+			   "path of file providing base BTF"),
+		OPT_END()
+	};
+	int err = -1;
+
+	argc = parse_options(argc, argv, btfid_options, resolve_btfids_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+	if (argc != 1)
+		usage_with_options(resolve_btfids_usage, btfid_options);
+
+	obj.path = argv[0];
+
+	if (elf_collect(&obj))
+		goto out;
+
+	/*
+	 * We did not find .BTF_ids section or symbols section,
+	 * nothing to do..
+	 */
+	if (obj.efile.idlist_shndx == -1 ||
+	    obj.efile.symbols_shndx == -1) {
+		pr_debug("Cannot find .BTF_ids or symbols sections, nothing to do\n");
+		err = 0;
+		goto out;
+	}
+
+	if (symbols_collect(&obj))
+		goto out;
+
+	if (symbols_resolve(&obj))
+		goto out;
+
+	if (symbols_patch(&obj))
+		goto out;
+
+	err = 0;
+out:
+	if (obj.efile.elf) {
+		elf_end(obj.efile.elf);
+		close(obj.efile.fd);
+	}
+	return err;
+}