33 static void freader_init_from_file(struct freader *r, void *buf, u32 buf_sz,  in freader_init_from_file()  argument
36 	memset(r, 0, sizeof(*r));  in freader_init_from_file()
37 	r->buf = buf;  in freader_init_from_file()
38 	r->buf_sz = buf_sz;  in freader_init_from_file()
39 	r->file = file;  in freader_init_from_file()
40 	r->may_fault = may_fault;  in freader_init_from_file()
43 static void freader_init_from_mem(struct freader *r, const char *data, u64 data_sz)  in freader_init_from_mem()  argument
45 	memset(r, 0, sizeof(*r));  in freader_init_from_mem()
46 	r->data = data;  in freader_init_from_mem()
47 	r->data_sz = data_sz;  in freader_init_from_mem()
50 static void freader_put_folio(struct freader *r)  in freader_put_folio()  argument
52 	if (!r->folio)  in freader_put_folio()
54 	kunmap_local(r->addr);  in freader_put_folio()
55 	folio_put(r->folio);  in freader_put_folio()
56 	r->folio = NULL;  in freader_put_folio()
59 static int freader_get_folio(struct freader *r, loff_t file_off)  in freader_get_folio()  argument
62 	if (r->folio && file_off >= r->folio_off &&  in freader_get_folio()
63 	    file_off < r->folio_off + folio_size(r->folio))  in freader_get_folio()
66 	freader_put_folio(r);  in freader_get_folio()
69 	if (secretmem_mapping(r->file->f_mapping))  in freader_get_folio()
72 	r->folio = filemap_get_folio(r->file->f_mapping, file_off >> PAGE_SHIFT);  in freader_get_folio()
75 	if (r->may_fault && (IS_ERR(r->folio) || !folio_test_uptodate(r->folio))) {  in freader_get_folio()
76 		filemap_invalidate_lock_shared(r->file->f_mapping);  in freader_get_folio()
77 		r->folio = read_cache_folio(r->file->f_mapping, file_off >> PAGE_SHIFT,  in freader_get_folio()
78 					    NULL, r->file);  in freader_get_folio()
79 		filemap_invalidate_unlock_shared(r->file->f_mapping);  in freader_get_folio()
82 	if (IS_ERR(r->folio) || !folio_test_uptodate(r->folio)) {  in freader_get_folio()
83 		if (!IS_ERR(r->folio))  in freader_get_folio()
84 			folio_put(r->folio);  in freader_get_folio()
85 		r->folio = NULL;  in freader_get_folio()
89 	r->folio_off = folio_pos(r->folio);  in freader_get_folio()
90 	r->addr = kmap_local_folio(r->folio, 0);  in freader_get_folio()
95 static const void *freader_fetch(struct freader *r, loff_t file_off, size_t sz)  in freader_fetch()  argument
100 	if (WARN_ON(r->buf && sz > r->buf_sz)) {  in freader_fetch()
101 		r->err = -E2BIG;  in freader_fetch()
106 		r->err = -EOVERFLOW;  in freader_fetch()
111 	if (!r->buf) {  in freader_fetch()
112 		if (file_off + sz > r->data_sz) {  in freader_fetch()
113 			r->err = -ERANGE;  in freader_fetch()
116 		return r->data + file_off;  in freader_fetch()
120 	r->err = freader_get_folio(r, file_off);  in freader_fetch()
121 	if (r->err)  in freader_fetch()
128 	folio_sz = folio_size(r->folio);  in freader_fetch()
129 	if (file_off + sz > r->folio_off + folio_sz) {  in freader_fetch()
130 		int part_sz = r->folio_off + folio_sz - file_off;  in freader_fetch()
133 		memcpy(r->buf, r->addr + (file_off - r->folio_off), part_sz);  in freader_fetch()
136 		r->err = freader_get_folio(r, r->folio_off + folio_sz);  in freader_fetch()
137 		if (r->err)  in freader_fetch()
141 		memcpy(r->buf + part_sz, r->addr, sz - part_sz);  in freader_fetch()
143 		return r->buf;  in freader_fetch()
147 	return r->addr + (file_off - r->folio_off);  in freader_fetch()
150 static void freader_cleanup(struct freader *r)  in freader_cleanup()  argument
152 	if (!r->buf)  in freader_cleanup()
155 	freader_put_folio(r);  in freader_cleanup()
163 static int parse_build_id(struct freader *r, unsigned char *build_id, __u32 *size,  in parse_build_id()  argument
176 		nhdr = freader_fetch(r, note_off, sizeof(Elf32_Nhdr) + note_name_sz);  in parse_build_id()
178 			return r->err;  in parse_build_id()
196 			data = freader_fetch(r, build_id_off, desc_sz);  in parse_build_id()
198 				return r->err;  in parse_build_id()
214 static int get_build_id_32(struct freader *r, unsigned char *build_id, __u32 *size)  in get_build_id_32()  argument
220 	ehdr = freader_fetch(r, 0, sizeof(Elf32_Ehdr));  in get_build_id_32()
222 		return r->err;  in get_build_id_32()
237 		phdr = freader_fetch(r, phoff + i * sizeof(Elf32_Phdr), sizeof(Elf32_Phdr));  in get_build_id_32()
239 			return r->err;  in get_build_id_32()
242 		    !parse_build_id(r, build_id, size, READ_ONCE(phdr->p_offset),  in get_build_id_32()
250 static int get_build_id_64(struct freader *r, unsigned char *build_id, __u32 *size)  in get_build_id_64()  argument
257 	ehdr = freader_fetch(r, 0, sizeof(Elf64_Ehdr));  in get_build_id_64()
259 		return r->err;  in get_build_id_64()
274 		phdr = freader_fetch(r, phoff + i * sizeof(Elf64_Phdr), sizeof(Elf64_Phdr));  in get_build_id_64()
276 			return r->err;  in get_build_id_64()
279 		    !parse_build_id(r, build_id, size, READ_ONCE(phdr->p_offset),  in get_build_id_64()
294 	struct freader r;  in __build_id_parse()  local
302 	freader_init_from_file(&r, buf, sizeof(buf), vma->vm_file, may_fault);  in __build_id_parse()
305 	ehdr = freader_fetch(&r, 0, offsetofend(Elf32_Ehdr, e_type));  in __build_id_parse()
307 		ret = r.err;  in __build_id_parse()
322 		ret = get_build_id_32(&r, build_id, size);  in __build_id_parse()
324 		ret = get_build_id_64(&r, build_id, size);  in __build_id_parse()
326 	freader_cleanup(&r);  in __build_id_parse()
372 	struct freader r;  in build_id_parse_buf()  local
375 	freader_init_from_mem(&r, buf, buf_size);  in build_id_parse_buf()
377 	err = parse_build_id(&r, build_id, NULL, 0, buf_size);  in build_id_parse_buf()
379 	freader_cleanup(&r);  in build_id_parse_buf()