2 * Copyright (c) 2003-2008 Joseph Koshy
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/types.h>
31 #include <sys/cpuset.h>
32 #include <sys/param.h>
33 #include <sys/endian.h>
35 #include <sys/imgact_aout.h>
36 #include <sys/imgact_elf.h>
38 #include <netinet/in.h>
51 #include "libpmcstat.h"
53 #define min(A,B) ((A) < (B) ? (A) : (B))
54 #define max(A,B) ((A) > (B) ? (A) : (B))
57 * Add the list of symbols in the given section to the list associated
61 pmcstat_image_add_symbols(struct pmcstat_image *image, Elf *e,
62 Elf_Scn *scn, GElf_Shdr *sh)
65 size_t n, newsyms, nshsyms, nfuncsyms;
66 struct pmcstat_symbol *symptr;
71 if ((data = elf_getdata(scn, NULL)) == NULL)
75 * Determine the number of functions named in this
79 nshsyms = sh->sh_size / sh->sh_entsize;
80 for (n = nfuncsyms = 0; n < nshsyms; n++) {
81 if (gelf_getsym(data, (int) n, &sym) != &sym)
83 if (GELF_ST_TYPE(sym.st_info) == STT_FUNC)
91 * Allocate space for the new entries.
93 firsttime = image->pi_symbols == NULL;
94 symptr = reallocarray(image->pi_symbols,
95 image->pi_symcount + nfuncsyms, sizeof(*symptr));
96 if (symptr == image->pi_symbols) /* realloc() failed. */
98 image->pi_symbols = symptr;
101 * Append new symbols to the end of the current table.
103 symptr += image->pi_symcount;
105 for (n = newsyms = 0; n < nshsyms; n++) {
106 if (gelf_getsym(data, (int) n, &sym) != &sym)
108 if (GELF_ST_TYPE(sym.st_info) != STT_FUNC)
111 if (sym.st_shndx == STN_UNDEF)
114 if (!firsttime && pmcstat_symbol_search(image, sym.st_value))
115 continue; /* We've seen this symbol already. */
117 if ((fnname = elf_strptr(e, sh->sh_link, sym.st_name))
121 /* Remove spurious ARM function name. */
122 if (fnname[0] == '$' &&
123 (fnname[1] == 'a' || fnname[1] == 't' ||
129 symptr->ps_name = pmcstat_string_intern(fnname);
130 symptr->ps_start = sym.st_value - image->pi_vaddr;
131 symptr->ps_end = symptr->ps_start + sym.st_size;
137 image->pi_symcount += newsyms;
138 if (image->pi_symcount == 0)
141 assert(newsyms <= nfuncsyms);
144 * Return space to the system if there were duplicates.
146 if (newsyms < nfuncsyms)
147 image->pi_symbols = reallocarray(image->pi_symbols,
148 image->pi_symcount, sizeof(*symptr));
151 * Keep the list of symbols sorted.
153 qsort(image->pi_symbols, image->pi_symcount, sizeof(*symptr),
154 pmcstat_symbol_compare);
157 * Deal with function symbols that have a size of 'zero' by
158 * making them extend to the next higher address. These
159 * symbols are usually defined in assembly code.
161 for (symptr = image->pi_symbols;
162 symptr < image->pi_symbols + (image->pi_symcount - 1);
164 if (symptr->ps_start == symptr->ps_end)
165 symptr->ps_end = (symptr+1)->ps_start;
169 * Record the fact that PC values from 'start' to 'end' come from
174 pmcstat_image_link(struct pmcstat_process *pp, struct pmcstat_image *image,
177 struct pmcstat_pcmap *pcm, *pcmnew;
180 assert(image->pi_type != PMCSTAT_IMAGE_UNKNOWN &&
181 image->pi_type != PMCSTAT_IMAGE_INDETERMINABLE);
183 if ((pcmnew = malloc(sizeof(*pcmnew))) == NULL)
184 err(EX_OSERR, "ERROR: Cannot create a map entry");
187 * Adjust the map entry to only cover the text portion
191 offset = start - image->pi_vaddr;
192 pcmnew->ppm_lowpc = image->pi_start + offset;
193 pcmnew->ppm_highpc = image->pi_end + offset;
194 pcmnew->ppm_image = image;
196 assert(pcmnew->ppm_lowpc < pcmnew->ppm_highpc);
198 /* Overlapped mmap()'s are assumed to never occur. */
199 TAILQ_FOREACH(pcm, &pp->pp_map, ppm_next)
200 if (pcm->ppm_lowpc >= pcmnew->ppm_highpc)
204 TAILQ_INSERT_TAIL(&pp->pp_map, pcmnew, ppm_next);
206 TAILQ_INSERT_BEFORE(pcm, pcmnew, ppm_next);
210 * Determine whether a given executable image is an A.OUT object, and
211 * if so, fill in its parameters from the text file.
212 * Sets image->pi_type.
216 pmcstat_image_get_aout_params(struct pmcstat_image *image,
217 struct pmcstat_args *args)
223 char buffer[PATH_MAX];
225 path = pmcstat_string_unintern(image->pi_execpath);
226 assert(path != NULL);
228 if (image->pi_iskernelmodule)
230 "ERROR: a.out kernel modules are unsupported \"%s\"", path);
232 (void) snprintf(buffer, sizeof(buffer), "%s%s",
233 args->pa_fsroot, path);
235 if ((fd = open(buffer, O_RDONLY, 0)) < 0 ||
236 (nbytes = read(fd, &ex, sizeof(ex))) < 0) {
237 if (args->pa_verbosity >= 2)
238 warn("WARNING: Cannot determine type of \"%s\"",
240 image->pi_type = PMCSTAT_IMAGE_INDETERMINABLE;
248 if ((unsigned) nbytes != sizeof(ex) ||
252 image->pi_type = PMCSTAT_IMAGE_AOUT;
254 /* TODO: the rest of a.out processing */
260 * Examine an ELF file to determine the size of its text segment.
261 * Sets image->pi_type if anything conclusive can be determined about
266 pmcstat_image_get_elf_params(struct pmcstat_image *image,
267 struct pmcstat_args *args)
271 const char *path, *elfbase;
273 uintfptr_t minva, maxva;
279 enum pmcstat_image_type image_type;
280 char buffer[PATH_MAX];
281 char buffer_modules[PATH_MAX];
283 assert(image->pi_type == PMCSTAT_IMAGE_UNKNOWN);
285 image->pi_start = minva = ~(uintfptr_t) 0;
286 image->pi_end = maxva = (uintfptr_t) 0;
287 image->pi_type = image_type = PMCSTAT_IMAGE_INDETERMINABLE;
288 image->pi_isdynamic = 0;
289 image->pi_dynlinkerpath = NULL;
292 path = pmcstat_string_unintern(image->pi_execpath);
293 assert(path != NULL);
296 * Look for kernel modules under FSROOT/KERNELPATH/NAME and
297 * FSROOT/boot/modules/NAME, and user mode executable objects
298 * under FSROOT/PATHNAME.
300 if (image->pi_iskernelmodule) {
301 (void) snprintf(buffer, sizeof(buffer), "%s%s/%s",
302 args->pa_fsroot, args->pa_kernel, path);
303 (void) snprintf(buffer_modules, sizeof(buffer_modules),
304 "%s/boot/modules/%s", args->pa_fsroot, path);
306 (void) snprintf(buffer, sizeof(buffer), "%s%s",
307 args->pa_fsroot, path);
311 fd = open(buffer, O_RDONLY, 0);
312 if (fd < 0 && !image->pi_iskernelmodule) {
313 warnx("WARNING: Cannot open \"%s\".",
317 if (fd < 0 && (fd = open(buffer_modules, O_RDONLY, 0)) < 0) {
318 warnx("WARNING: Cannot open \"%s\" or \"%s\".",
319 buffer, buffer_modules);
322 if (elf_version(EV_CURRENT) == EV_NONE) {
323 warnx("WARNING: failed to init elf\n");
327 if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
328 warnx("WARNING: Cannot read \"%s\".",
333 if (elf_kind(e) != ELF_K_ELF) {
334 if (args->pa_verbosity >= 2)
335 warnx("WARNING: Cannot determine the type of \"%s\".",
340 if (gelf_getehdr(e, &eh) != &eh) {
342 "WARNING: Cannot retrieve the ELF Header for \"%s\": %s.",
343 buffer, elf_errmsg(-1));
347 if (eh.e_type != ET_EXEC && eh.e_type != ET_DYN &&
348 !(image->pi_iskernelmodule && eh.e_type == ET_REL)) {
349 warnx("WARNING: \"%s\" is of an unsupported ELF type.",
354 image_type = eh.e_ident[EI_CLASS] == ELFCLASS32 ?
355 PMCSTAT_IMAGE_ELF32 : PMCSTAT_IMAGE_ELF64;
358 * Determine the virtual address where an executable would be
359 * loaded. Additionally, for dynamically linked executables,
360 * save the pathname to the runtime linker.
362 if (eh.e_type == ET_EXEC) {
363 if (elf_getphnum(e, &nph) == 0) {
365 "WARNING: Could not determine the number of program headers in \"%s\": %s.",
370 for (i = 0; i < eh.e_phnum; i++) {
371 if (gelf_getphdr(e, i, &ph) != &ph) {
373 "WARNING: Retrieval of PHDR entry #%ju in \"%s\" failed: %s.",
374 (uintmax_t) i, buffer, elf_errmsg(-1));
379 image->pi_isdynamic = 1;
382 if ((elfbase = elf_rawfile(e, NULL)) == NULL) {
384 "WARNING: Cannot retrieve the interpreter for \"%s\": %s.",
385 buffer, elf_errmsg(-1));
388 image->pi_dynlinkerpath =
389 pmcstat_string_intern(elfbase +
393 if ((ph.p_flags & PF_X) != 0 &&
394 (ph.p_offset & (-ph.p_align)) == 0)
395 image->pi_vaddr = ph.p_vaddr & (-ph.p_align);
402 * Get the min and max VA associated with this ELF object.
404 if (elf_getshnum(e, &nsh) == 0) {
406 "WARNING: Could not determine the number of sections for \"%s\": %s.",
407 buffer, elf_errmsg(-1));
411 for (i = 0; i < nsh; i++) {
412 if ((scn = elf_getscn(e, i)) == NULL ||
413 gelf_getshdr(scn, &sh) != &sh) {
415 "WARNING: Could not retrieve section header #%ju in \"%s\": %s.",
416 (uintmax_t) i, buffer, elf_errmsg(-1));
419 if (sh.sh_flags & SHF_EXECINSTR) {
420 minva = min(minva, sh.sh_addr);
421 maxva = max(maxva, sh.sh_addr + sh.sh_size);
423 if (sh.sh_type == SHT_SYMTAB || sh.sh_type == SHT_DYNSYM)
424 pmcstat_image_add_symbols(image, e, scn, &sh);
427 image->pi_start = minva;
428 image->pi_end = maxva;
429 image->pi_type = image_type;
430 image->pi_fullpath = pmcstat_string_intern(buffer);
432 /* Build display name
435 for (p = buffer; *p; p++)
438 image->pi_name = pmcstat_string_intern(endp);
448 * Given an image descriptor, determine whether it is an ELF, or AOUT.
449 * If no handler claims the image, set its type to 'INDETERMINABLE'.
453 pmcstat_image_determine_type(struct pmcstat_image *image,
454 struct pmcstat_args *args)
456 assert(image->pi_type == PMCSTAT_IMAGE_UNKNOWN);
458 /* Try each kind of handler in turn */
459 if (image->pi_type == PMCSTAT_IMAGE_UNKNOWN)
460 pmcstat_image_get_elf_params(image, args);
461 if (image->pi_type == PMCSTAT_IMAGE_UNKNOWN)
462 pmcstat_image_get_aout_params(image, args);
465 * Otherwise, remember that we tried to determine
466 * the object's type and had failed.
468 if (image->pi_type == PMCSTAT_IMAGE_UNKNOWN)
469 image->pi_type = PMCSTAT_IMAGE_INDETERMINABLE;
473 * Locate an image descriptor given an interned path, adding a fresh
474 * descriptor to the cache if necessary. This function also finds a
475 * suitable name for this image's sample file.
477 * We defer filling in the file format specific parts of the image
478 * structure till the time we actually see a sample that would fall
482 struct pmcstat_image *
483 pmcstat_image_from_path(pmcstat_interned_string internedpath,
484 int iskernelmodule, struct pmcstat_args *args,
485 struct pmc_plugins *plugins)
488 struct pmcstat_image *pi;
490 hash = pmcstat_string_lookup_hash(internedpath);
492 /* First, look for an existing entry. */
493 LIST_FOREACH(pi, &pmcstat_image_hash[hash], pi_next)
494 if (pi->pi_execpath == internedpath &&
495 pi->pi_iskernelmodule == iskernelmodule)
499 * Allocate a new entry and place it at the head of the hash
502 pi = malloc(sizeof(*pi));
506 pi->pi_type = PMCSTAT_IMAGE_UNKNOWN;
507 pi->pi_execpath = internedpath;
512 pi->pi_isdynamic = 0;
513 pi->pi_iskernelmodule = iskernelmodule;
514 pi->pi_dynlinkerpath = NULL;
515 pi->pi_symbols = NULL;
517 pi->pi_addr2line = NULL;
519 if (plugins[args->pa_pplugin].pl_initimage != NULL)
520 plugins[args->pa_pplugin].pl_initimage(pi);
521 if (plugins[args->pa_plugin].pl_initimage != NULL)
522 plugins[args->pa_plugin].pl_initimage(pi);
524 LIST_INSERT_HEAD(&pmcstat_image_hash[hash], pi, pi_next);