| /* Standard libdwfl callbacks for debugging the running Linux kernel. |
| Copyright (C) 2005-2011, 2013, 2014 Red Hat, Inc. |
| This file is part of elfutils. |
| |
| This file is free software; you can redistribute it and/or modify |
| it under the terms of either |
| |
| * the GNU Lesser General Public License as published by the Free |
| Software Foundation; either version 3 of the License, or (at |
| your option) any later version |
| |
| or |
| |
| * the GNU General Public License as published by the Free |
| Software Foundation; either version 2 of the License, or (at |
| your option) any later version |
| |
| or both in parallel, as here. |
| |
| elfutils is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received copies of the GNU General Public License and |
| the GNU Lesser General Public License along with this program. If |
| not, see <http://www.gnu.org/licenses/>. */ |
| |
| /* We include this before config.h because it can't handle _FILE_OFFSET_BITS. |
| Everything we need here is fine if its declarations just come first. */ |
| |
| #include <fts.h> |
| |
| #include <config.h> |
| |
| #include "libdwflP.h" |
| #include <inttypes.h> |
| #include <errno.h> |
| #include <stdio.h> |
| #include <stdio_ext.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <sys/utsname.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| |
| |
| #define KERNEL_MODNAME "kernel" |
| |
| #define MODULEDIRFMT "/lib/modules/%s" |
| |
| #define KNOTESFILE "/sys/kernel/notes" |
| #define MODNOTESFMT "/sys/module/%s/notes" |
| #define KSYMSFILE "/proc/kallsyms" |
| #define MODULELIST "/proc/modules" |
| #define SECADDRDIRFMT "/sys/module/%s/sections/" |
| #define MODULE_SECT_NAME_LEN 32 /* Minimum any linux/module.h has had. */ |
| |
| |
| #if defined (USE_ZLIB) || defined (USE_BZLIB) || defined (USE_LZMA) |
| static const char *vmlinux_suffixes[] = |
| { |
| #ifdef USE_ZLIB |
| ".gz", |
| #endif |
| #ifdef USE_BZLIB |
| ".bz2", |
| #endif |
| #ifdef USE_LZMA |
| ".xz", |
| #endif |
| }; |
| #endif |
| |
| /* Try to open the given file as it is or under the debuginfo directory. */ |
| static int |
| try_kernel_name (Dwfl *dwfl, char **fname, bool try_debug) |
| { |
| if (*fname == NULL) |
| return -1; |
| |
| /* Don't bother trying *FNAME itself here if the path will cause it to be |
| tried because we give its own basename as DEBUGLINK_FILE. */ |
| int fd = ((((dwfl->callbacks->debuginfo_path |
| ? *dwfl->callbacks->debuginfo_path : NULL) |
| ?: DEFAULT_DEBUGINFO_PATH)[0] == ':') ? -1 |
| : TEMP_FAILURE_RETRY (open64 (*fname, O_RDONLY))); |
| |
| if (fd < 0) |
| { |
| Dwfl_Module fakemod = { .dwfl = dwfl }; |
| /* First try the file's unadorned basename as DEBUGLINK_FILE, |
| to look for "vmlinux" files. */ |
| fd = INTUSE(dwfl_standard_find_debuginfo) (&fakemod, NULL, NULL, 0, |
| *fname, basename (*fname), 0, |
| &fakemod.debug.name); |
| if (fd < 0 && try_debug) |
| /* Next, let the call use the default of basename + ".debug", |
| to look for "vmlinux.debug" files. */ |
| fd = INTUSE(dwfl_standard_find_debuginfo) (&fakemod, NULL, NULL, 0, |
| *fname, NULL, 0, |
| &fakemod.debug.name); |
| if (fakemod.debug.name != NULL) |
| { |
| free (*fname); |
| *fname = fakemod.debug.name; |
| } |
| } |
| |
| #if defined (USE_ZLIB) || defined (USE_BZLIB) || defined (USE_LZMA) |
| if (fd < 0) |
| for (size_t i = 0; |
| i < sizeof vmlinux_suffixes / sizeof vmlinux_suffixes[0]; |
| ++i) |
| { |
| char *zname; |
| if (asprintf (&zname, "%s%s", *fname, vmlinux_suffixes[i]) > 0) |
| { |
| fd = TEMP_FAILURE_RETRY (open64 (zname, O_RDONLY)); |
| if (fd < 0) |
| free (zname); |
| else |
| { |
| free (*fname); |
| *fname = zname; |
| } |
| } |
| } |
| #endif |
| |
| if (fd < 0) |
| { |
| free (*fname); |
| *fname = NULL; |
| } |
| |
| return fd; |
| } |
| |
| static inline const char * |
| kernel_release (void) |
| { |
| /* Cache the `uname -r` string we'll use. */ |
| static struct utsname utsname; |
| if (utsname.release[0] == '\0' && uname (&utsname) != 0) |
| return NULL; |
| return utsname.release; |
| } |
| |
| static int |
| find_kernel_elf (Dwfl *dwfl, const char *release, char **fname) |
| { |
| if ((release[0] == '/' |
| ? asprintf (fname, "%s/vmlinux", release) |
| : asprintf (fname, "/boot/vmlinux-%s", release)) < 0) |
| return -1; |
| |
| int fd = try_kernel_name (dwfl, fname, true); |
| if (fd < 0 && release[0] != '/') |
| { |
| free (*fname); |
| if (asprintf (fname, MODULEDIRFMT "/vmlinux", release) < 0) |
| return -1; |
| fd = try_kernel_name (dwfl, fname, true); |
| } |
| |
| return fd; |
| } |
| |
| static int |
| get_release (Dwfl *dwfl, const char **release) |
| { |
| if (dwfl == NULL) |
| return -1; |
| |
| const char *release_string = release == NULL ? NULL : *release; |
| if (release_string == NULL) |
| { |
| release_string = kernel_release (); |
| if (release_string == NULL) |
| return errno; |
| if (release != NULL) |
| *release = release_string; |
| } |
| |
| return 0; |
| } |
| |
| static int |
| report_kernel (Dwfl *dwfl, const char **release, |
| int (*predicate) (const char *module, const char *file)) |
| { |
| int result = get_release (dwfl, release); |
| if (unlikely (result != 0)) |
| return result; |
| |
| char *fname; |
| int fd = find_kernel_elf (dwfl, *release, &fname); |
| |
| if (fd < 0) |
| result = ((predicate != NULL && !(*predicate) (KERNEL_MODNAME, NULL)) |
| ? 0 : errno ?: ENOENT); |
| else |
| { |
| bool report = true; |
| |
| if (predicate != NULL) |
| { |
| /* Let the predicate decide whether to use this one. */ |
| int want = (*predicate) (KERNEL_MODNAME, fname); |
| if (want < 0) |
| result = errno; |
| report = want > 0; |
| } |
| |
| if (report) |
| { |
| /* Note that on some architectures (e.g. x86_64) the vmlinux |
| is ET_EXEC, while on others (e.g. ppc64) it is ET_DYN. |
| In both cases the phdr p_vaddr load address will be non-zero. |
| We want the image to be placed as if it was ET_DYN, so |
| pass true for add_p_vaddr which will do the right thing |
| (in combination with a zero base) in either case. */ |
| Dwfl_Module *mod = INTUSE(dwfl_report_elf) (dwfl, KERNEL_MODNAME, |
| fname, fd, 0, true); |
| if (mod == NULL) |
| result = -1; |
| else |
| /* The kernel is ET_EXEC, but always treat it as relocatable. */ |
| mod->e_type = ET_DYN; |
| } |
| |
| free (fname); |
| |
| if (!report || result < 0) |
| close (fd); |
| } |
| |
| return result; |
| } |
| |
| /* Look for a kernel debug archive. If we find one, report all its modules. |
| If not, return ENOENT. */ |
| static int |
| report_kernel_archive (Dwfl *dwfl, const char **release, |
| int (*predicate) (const char *module, const char *file)) |
| { |
| int result = get_release (dwfl, release); |
| if (unlikely (result != 0)) |
| return result; |
| |
| char *archive; |
| int res = (((*release)[0] == '/') |
| ? asprintf (&archive, "%s/debug.a", *release) |
| : asprintf (&archive, MODULEDIRFMT "/debug.a", *release)); |
| if (unlikely (res < 0)) |
| return ENOMEM; |
| |
| int fd = try_kernel_name (dwfl, &archive, false); |
| if (fd < 0) |
| result = errno ?: ENOENT; |
| else |
| { |
| /* We have the archive file open! */ |
| Dwfl_Module *last = __libdwfl_report_offline (dwfl, NULL, archive, fd, |
| true, predicate); |
| if (unlikely (last == NULL)) |
| result = -1; |
| else |
| { |
| /* Find the kernel and move it to the head of the list. */ |
| Dwfl_Module **tailp = &dwfl->modulelist, **prevp = tailp; |
| for (Dwfl_Module *m = *prevp; m != NULL; m = *(prevp = &m->next)) |
| if (!m->gc && m->e_type != ET_REL && !strcmp (m->name, "kernel")) |
| { |
| *prevp = m->next; |
| m->next = *tailp; |
| *tailp = m; |
| break; |
| } |
| } |
| } |
| |
| free (archive); |
| return result; |
| } |
| |
| static size_t |
| check_suffix (const FTSENT *f, size_t namelen) |
| { |
| #define TRY(sfx) \ |
| if ((namelen ? f->fts_namelen == namelen + sizeof sfx - 1 \ |
| : f->fts_namelen >= sizeof sfx) \ |
| && !memcmp (f->fts_name + f->fts_namelen - (sizeof sfx - 1), \ |
| sfx, sizeof sfx)) \ |
| return sizeof sfx - 1 |
| |
| TRY (".ko"); |
| #if USE_ZLIB |
| TRY (".ko.gz"); |
| #endif |
| #if USE_BZLIB |
| TRY (".ko.bz2"); |
| #endif |
| #if USE_LZMA |
| TRY (".ko.xz"); |
| #endif |
| |
| return 0; |
| |
| #undef TRY |
| } |
| |
| /* Report a kernel and all its modules found on disk, for offline use. |
| If RELEASE starts with '/', it names a directory to look in; |
| if not, it names a directory to find under /lib/modules/; |
| if null, /lib/modules/`uname -r` is used. |
| Returns zero on success, -1 if dwfl_report_module failed, |
| or an errno code if finding the files on disk failed. */ |
| int |
| dwfl_linux_kernel_report_offline (Dwfl *dwfl, const char *release, |
| int (*predicate) (const char *module, |
| const char *file)) |
| { |
| int result = report_kernel_archive (dwfl, &release, predicate); |
| if (result != ENOENT) |
| return result; |
| |
| /* First report the kernel. */ |
| result = report_kernel (dwfl, &release, predicate); |
| if (result == 0) |
| { |
| /* Do "find /lib/modules/RELEASE -name *.ko". */ |
| |
| char *modulesdir[] = { NULL, NULL }; |
| if (release[0] == '/') |
| modulesdir[0] = (char *) release; |
| else |
| { |
| if (asprintf (&modulesdir[0], MODULEDIRFMT, release) < 0) |
| return errno; |
| } |
| |
| FTS *fts = fts_open (modulesdir, FTS_NOSTAT | FTS_LOGICAL, NULL); |
| if (modulesdir[0] == (char *) release) |
| modulesdir[0] = NULL; |
| if (fts == NULL) |
| { |
| free (modulesdir[0]); |
| return errno; |
| } |
| |
| FTSENT *f; |
| while ((f = fts_read (fts)) != NULL) |
| { |
| /* Skip a "source" subtree, which tends to be large. |
| This insane hard-coding of names is what depmod does too. */ |
| if (f->fts_namelen == sizeof "source" - 1 |
| && !strcmp (f->fts_name, "source")) |
| { |
| fts_set (fts, f, FTS_SKIP); |
| continue; |
| } |
| |
| switch (f->fts_info) |
| { |
| case FTS_F: |
| case FTS_SL: |
| case FTS_NSOK:; |
| /* See if this file name matches "*.ko". */ |
| const size_t suffix = check_suffix (f, 0); |
| if (suffix) |
| { |
| /* We have a .ko file to report. Following the algorithm |
| by which the kernel makefiles set KBUILD_MODNAME, we |
| replace all ',' or '-' with '_' in the file name and |
| call that the module name. Modules could well be |
| built using different embedded names than their file |
| names. To handle that, we would have to look at the |
| __this_module.name contents in the module's text. */ |
| |
| char name[f->fts_namelen - suffix + 1]; |
| for (size_t i = 0; i < f->fts_namelen - 3U; ++i) |
| if (f->fts_name[i] == '-' || f->fts_name[i] == ',') |
| name[i] = '_'; |
| else |
| name[i] = f->fts_name[i]; |
| name[f->fts_namelen - suffix] = '\0'; |
| |
| if (predicate != NULL) |
| { |
| /* Let the predicate decide whether to use this one. */ |
| int want = (*predicate) (name, f->fts_path); |
| if (want < 0) |
| { |
| result = -1; |
| break; |
| } |
| if (!want) |
| continue; |
| } |
| |
| if (dwfl_report_offline (dwfl, name, f->fts_path, -1) == NULL) |
| { |
| result = -1; |
| break; |
| } |
| } |
| continue; |
| |
| case FTS_ERR: |
| case FTS_DNR: |
| case FTS_NS: |
| result = f->fts_errno; |
| break; |
| |
| case FTS_SLNONE: |
| default: |
| continue; |
| } |
| |
| /* We only get here in error cases. */ |
| break; |
| } |
| fts_close (fts); |
| free (modulesdir[0]); |
| } |
| |
| return result; |
| } |
| INTDEF (dwfl_linux_kernel_report_offline) |
| |
| |
| /* Grovel around to guess the bounds of the runtime kernel image. */ |
| static int |
| intuit_kernel_bounds (Dwarf_Addr *start, Dwarf_Addr *end, Dwarf_Addr *notes) |
| { |
| FILE *f = fopen (KSYMSFILE, "r"); |
| if (f == NULL) |
| return errno; |
| |
| (void) __fsetlocking (f, FSETLOCKING_BYCALLER); |
| |
| *notes = 0; |
| |
| char *line = NULL; |
| size_t linesz = 0; |
| size_t n; |
| char *p = NULL; |
| const char *type; |
| |
| inline bool read_address (Dwarf_Addr *addr) |
| { |
| if ((n = getline (&line, &linesz, f)) < 1 || line[n - 2] == ']') |
| return false; |
| *addr = strtoull (line, &p, 16); |
| p += strspn (p, " \t"); |
| type = strsep (&p, " \t\n"); |
| if (type == NULL) |
| return false; |
| return p != NULL && p != line; |
| } |
| |
| int result; |
| do |
| result = read_address (start) ? 0 : -1; |
| while (result == 0 && strchr ("TtRr", *type) == NULL); |
| |
| if (result == 0) |
| { |
| *end = *start; |
| while (read_address (end)) |
| if (*notes == 0 && !strcmp (p, "__start_notes\n")) |
| *notes = *end; |
| |
| Dwarf_Addr round_kernel = sysconf (_SC_PAGE_SIZE); |
| *start &= -(Dwarf_Addr) round_kernel; |
| *end += round_kernel - 1; |
| *end &= -(Dwarf_Addr) round_kernel; |
| if (*start >= *end || *end - *start < round_kernel) |
| result = -1; |
| } |
| free (line); |
| |
| if (result == -1) |
| result = ferror_unlocked (f) ? errno : ENOEXEC; |
| |
| fclose (f); |
| |
| return result; |
| } |
| |
| |
| /* Look for a build ID note in NOTESFILE and associate the ID with MOD. */ |
| static int |
| check_notes (Dwfl_Module *mod, const char *notesfile, |
| Dwarf_Addr vaddr, const char *secname) |
| { |
| int fd = open64 (notesfile, O_RDONLY); |
| if (fd < 0) |
| return 1; |
| |
| assert (sizeof (Elf32_Nhdr) == sizeof (GElf_Nhdr)); |
| assert (sizeof (Elf64_Nhdr) == sizeof (GElf_Nhdr)); |
| union |
| { |
| GElf_Nhdr nhdr; |
| unsigned char data[8192]; |
| } buf; |
| |
| ssize_t n = read (fd, buf.data, sizeof buf); |
| close (fd); |
| |
| if (n <= 0) |
| return 1; |
| |
| unsigned char *p = buf.data; |
| while (p < &buf.data[n]) |
| { |
| /* No translation required since we are reading the native kernel. */ |
| GElf_Nhdr *nhdr = (void *) p; |
| p += sizeof *nhdr; |
| unsigned char *name = p; |
| p += (nhdr->n_namesz + 3) & -4U; |
| unsigned char *bits = p; |
| p += (nhdr->n_descsz + 3) & -4U; |
| |
| if (p <= &buf.data[n] |
| && nhdr->n_type == NT_GNU_BUILD_ID |
| && nhdr->n_namesz == sizeof "GNU" |
| && !memcmp (name, "GNU", sizeof "GNU")) |
| { |
| /* Found it. For a module we must figure out its VADDR now. */ |
| |
| if (secname != NULL |
| && (INTUSE(dwfl_linux_kernel_module_section_address) |
| (mod, NULL, mod->name, 0, secname, 0, NULL, &vaddr) != 0 |
| || vaddr == (GElf_Addr) -1l)) |
| vaddr = 0; |
| |
| if (vaddr != 0) |
| vaddr += bits - buf.data; |
| return INTUSE(dwfl_module_report_build_id) (mod, bits, |
| nhdr->n_descsz, vaddr); |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* Look for a build ID for the kernel. */ |
| static int |
| check_kernel_notes (Dwfl_Module *kernelmod, GElf_Addr vaddr) |
| { |
| return check_notes (kernelmod, KNOTESFILE, vaddr, NULL) < 0 ? -1 : 0; |
| } |
| |
| /* Look for a build ID for a loaded kernel module. */ |
| static int |
| check_module_notes (Dwfl_Module *mod) |
| { |
| char *dirs[2] = { NULL, NULL }; |
| if (asprintf (&dirs[0], MODNOTESFMT, mod->name) < 0) |
| return ENOMEM; |
| |
| FTS *fts = fts_open (dirs, FTS_NOSTAT | FTS_LOGICAL, NULL); |
| if (fts == NULL) |
| { |
| free (dirs[0]); |
| return 0; |
| } |
| |
| int result = 0; |
| FTSENT *f; |
| while ((f = fts_read (fts)) != NULL) |
| { |
| switch (f->fts_info) |
| { |
| case FTS_F: |
| case FTS_SL: |
| case FTS_NSOK: |
| result = check_notes (mod, f->fts_accpath, 0, f->fts_name); |
| if (result > 0) /* Nothing found. */ |
| { |
| result = 0; |
| continue; |
| } |
| break; |
| |
| case FTS_ERR: |
| case FTS_DNR: |
| result = f->fts_errno; |
| break; |
| |
| case FTS_NS: |
| case FTS_SLNONE: |
| default: |
| continue; |
| } |
| |
| /* We only get here when finished or in error cases. */ |
| break; |
| } |
| fts_close (fts); |
| free (dirs[0]); |
| |
| return result; |
| } |
| |
| int |
| dwfl_linux_kernel_report_kernel (Dwfl *dwfl) |
| { |
| Dwarf_Addr start; |
| Dwarf_Addr end; |
| inline Dwfl_Module *report (void) |
| { |
| return INTUSE(dwfl_report_module) (dwfl, KERNEL_MODNAME, start, end); |
| } |
| |
| /* This is a bit of a kludge. If we already reported the kernel, |
| don't bother figuring it out again--it never changes. */ |
| for (Dwfl_Module *m = dwfl->modulelist; m != NULL; m = m->next) |
| if (!strcmp (m->name, KERNEL_MODNAME)) |
| { |
| start = m->low_addr; |
| end = m->high_addr; |
| return report () == NULL ? -1 : 0; |
| } |
| |
| /* Try to figure out the bounds of the kernel image without |
| looking for any vmlinux file. */ |
| Dwarf_Addr notes; |
| /* The compiler cannot deduce that if intuit_kernel_bounds returns |
| zero NOTES will be initialized. Fake the initialization. */ |
| asm ("" : "=m" (notes)); |
| int result = intuit_kernel_bounds (&start, &end, ¬es); |
| if (result == 0) |
| { |
| Dwfl_Module *mod = report (); |
| return unlikely (mod == NULL) ? -1 : check_kernel_notes (mod, notes); |
| } |
| if (result != ENOENT) |
| return result; |
| |
| /* Find the ELF file for the running kernel and dwfl_report_elf it. */ |
| return report_kernel (dwfl, NULL, NULL); |
| } |
| INTDEF (dwfl_linux_kernel_report_kernel) |
| |
| |
| /* Dwfl_Callbacks.find_elf for the running Linux kernel and its modules. */ |
| |
| int |
| dwfl_linux_kernel_find_elf (Dwfl_Module *mod, |
| void **userdata __attribute__ ((unused)), |
| const char *module_name, |
| Dwarf_Addr base __attribute__ ((unused)), |
| char **file_name, Elf **elfp) |
| { |
| if (mod->build_id_len > 0) |
| { |
| int fd = INTUSE(dwfl_build_id_find_elf) (mod, NULL, NULL, 0, |
| file_name, elfp); |
| if (fd >= 0 || mod->main.elf != NULL || errno != 0) |
| return fd; |
| } |
| |
| const char *release = kernel_release (); |
| if (release == NULL) |
| return errno; |
| |
| if (!strcmp (module_name, KERNEL_MODNAME)) |
| return find_kernel_elf (mod->dwfl, release, file_name); |
| |
| /* Do "find /lib/modules/`uname -r` -name MODULE_NAME.ko". */ |
| |
| char *modulesdir[] = { NULL, NULL }; |
| if (asprintf (&modulesdir[0], MODULEDIRFMT, release) < 0) |
| return -1; |
| |
| FTS *fts = fts_open (modulesdir, FTS_NOSTAT | FTS_LOGICAL, NULL); |
| if (fts == NULL) |
| { |
| free (modulesdir[0]); |
| return -1; |
| } |
| |
| size_t namelen = strlen (module_name); |
| |
| /* This is a kludge. There is no actual necessary relationship between |
| the name of the .ko file installed and the module name the kernel |
| knows it by when it's loaded. The kernel's only idea of the module |
| name comes from the name embedded in the object's magic |
| .gnu.linkonce.this_module section. |
| |
| In practice, these module names match the .ko file names except for |
| some using '_' and some using '-'. So our cheap kludge is to look for |
| two files when either a '_' or '-' appears in a module name, one using |
| only '_' and one only using '-'. */ |
| |
| char alternate_name[namelen + 1]; |
| inline bool subst_name (char from, char to) |
| { |
| const char *n = memchr (module_name, from, namelen); |
| if (n == NULL) |
| return false; |
| char *a = mempcpy (alternate_name, module_name, n - module_name); |
| *a++ = to; |
| ++n; |
| const char *p; |
| while ((p = memchr (n, from, namelen - (n - module_name))) != NULL) |
| { |
| a = mempcpy (a, n, p - n); |
| *a++ = to; |
| n = p + 1; |
| } |
| memcpy (a, n, namelen - (n - module_name) + 1); |
| return true; |
| } |
| if (!subst_name ('-', '_') && !subst_name ('_', '-')) |
| alternate_name[0] = '\0'; |
| |
| FTSENT *f; |
| int error = ENOENT; |
| while ((f = fts_read (fts)) != NULL) |
| { |
| /* Skip a "source" subtree, which tends to be large. |
| This insane hard-coding of names is what depmod does too. */ |
| if (f->fts_namelen == sizeof "source" - 1 |
| && !strcmp (f->fts_name, "source")) |
| { |
| fts_set (fts, f, FTS_SKIP); |
| continue; |
| } |
| |
| error = ENOENT; |
| switch (f->fts_info) |
| { |
| case FTS_F: |
| case FTS_SL: |
| case FTS_NSOK: |
| /* See if this file name is "MODULE_NAME.ko". */ |
| if (check_suffix (f, namelen) |
| && (!memcmp (f->fts_name, module_name, namelen) |
| || !memcmp (f->fts_name, alternate_name, namelen))) |
| { |
| int fd = open64 (f->fts_accpath, O_RDONLY); |
| *file_name = strdup (f->fts_path); |
| fts_close (fts); |
| free (modulesdir[0]); |
| if (fd < 0) |
| free (*file_name); |
| else if (*file_name == NULL) |
| { |
| close (fd); |
| fd = -1; |
| } |
| return fd; |
| } |
| break; |
| |
| case FTS_ERR: |
| case FTS_DNR: |
| case FTS_NS: |
| error = f->fts_errno; |
| break; |
| |
| case FTS_SLNONE: |
| default: |
| break; |
| } |
| } |
| |
| fts_close (fts); |
| free (modulesdir[0]); |
| errno = error; |
| return -1; |
| } |
| INTDEF (dwfl_linux_kernel_find_elf) |
| |
| |
| /* Dwfl_Callbacks.section_address for kernel modules in the running Linux. |
| We read the information from /sys/module directly. */ |
| |
| int |
| dwfl_linux_kernel_module_section_address |
| (Dwfl_Module *mod __attribute__ ((unused)), |
| void **userdata __attribute__ ((unused)), |
| const char *modname, Dwarf_Addr base __attribute__ ((unused)), |
| const char *secname, Elf32_Word shndx __attribute__ ((unused)), |
| const GElf_Shdr *shdr __attribute__ ((unused)), |
| Dwarf_Addr *addr) |
| { |
| char *sysfile; |
| if (asprintf (&sysfile, SECADDRDIRFMT "%s", modname, secname) < 0) |
| return DWARF_CB_ABORT; |
| |
| FILE *f = fopen (sysfile, "r"); |
| free (sysfile); |
| |
| if (f == NULL) |
| { |
| if (errno == ENOENT) |
| { |
| /* The .modinfo and .data.percpu sections are never kept |
| loaded in the kernel. If the kernel was compiled without |
| CONFIG_MODULE_UNLOAD, the .exit.* sections are not |
| actually loaded at all. |
| |
| Setting *ADDR to -1 tells the caller this section is |
| actually absent from memory. */ |
| |
| if (!strcmp (secname, ".modinfo") |
| || !strcmp (secname, ".data.percpu") |
| || !strncmp (secname, ".exit", 5)) |
| { |
| *addr = (Dwarf_Addr) -1l; |
| return DWARF_CB_OK; |
| } |
| |
| /* The goofy PPC64 module_frob_arch_sections function tweaks |
| the section names as a way to control other kernel code's |
| behavior, and this cruft leaks out into the /sys information. |
| The file name for ".init*" may actually look like "_init*". */ |
| |
| const bool is_init = !strncmp (secname, ".init", 5); |
| if (is_init) |
| { |
| if (asprintf (&sysfile, SECADDRDIRFMT "_%s", |
| modname, &secname[1]) < 0) |
| return ENOMEM; |
| f = fopen (sysfile, "r"); |
| free (sysfile); |
| if (f != NULL) |
| goto ok; |
| } |
| |
| /* The kernel truncates section names to MODULE_SECT_NAME_LEN - 1. |
| In case that size increases in the future, look for longer |
| truncated names first. */ |
| size_t namelen = strlen (secname); |
| if (namelen >= MODULE_SECT_NAME_LEN) |
| { |
| int len = asprintf (&sysfile, SECADDRDIRFMT "%s", |
| modname, secname); |
| if (len < 0) |
| return DWARF_CB_ABORT; |
| char *end = sysfile + len; |
| do |
| { |
| *--end = '\0'; |
| f = fopen (sysfile, "r"); |
| if (is_init && f == NULL && errno == ENOENT) |
| { |
| sysfile[len - namelen] = '_'; |
| f = fopen (sysfile, "r"); |
| sysfile[len - namelen] = '.'; |
| } |
| } |
| while (f == NULL && errno == ENOENT |
| && end - &sysfile[len - namelen] >= MODULE_SECT_NAME_LEN); |
| free (sysfile); |
| |
| if (f != NULL) |
| goto ok; |
| } |
| } |
| |
| return DWARF_CB_ABORT; |
| } |
| |
| ok: |
| (void) __fsetlocking (f, FSETLOCKING_BYCALLER); |
| |
| int result = (fscanf (f, "%" PRIx64 "\n", addr) == 1 ? 0 |
| : ferror_unlocked (f) ? errno : ENOEXEC); |
| fclose (f); |
| |
| if (result == 0) |
| return DWARF_CB_OK; |
| |
| errno = result; |
| return DWARF_CB_ABORT; |
| } |
| INTDEF (dwfl_linux_kernel_module_section_address) |
| |
| int |
| dwfl_linux_kernel_report_modules (Dwfl *dwfl) |
| { |
| FILE *f = fopen (MODULELIST, "r"); |
| if (f == NULL) |
| return errno; |
| |
| (void) __fsetlocking (f, FSETLOCKING_BYCALLER); |
| |
| int result = 0; |
| Dwarf_Addr modaddr; |
| unsigned long int modsz; |
| char modname[128]; |
| char *line = NULL; |
| size_t linesz = 0; |
| /* We can't just use fscanf here because it's not easy to distinguish \n |
| from other whitespace so as to take the optional word following the |
| address but always stop at the end of the line. */ |
| while (getline (&line, &linesz, f) > 0 |
| && sscanf (line, "%128s %lu %*s %*s %*s %" PRIx64 " %*s\n", |
| modname, &modsz, &modaddr) == 3) |
| { |
| Dwfl_Module *mod = INTUSE(dwfl_report_module) (dwfl, modname, |
| modaddr, modaddr + modsz); |
| if (mod == NULL) |
| { |
| result = -1; |
| break; |
| } |
| |
| result = check_module_notes (mod); |
| } |
| free (line); |
| |
| if (result == 0) |
| result = ferror_unlocked (f) ? errno : feof_unlocked (f) ? 0 : ENOEXEC; |
| |
| fclose (f); |
| |
| return result; |
| } |
| INTDEF (dwfl_linux_kernel_report_modules) |