From FEDORA_PATCHES Mon Sep 17 00:00:00 2001
From: Fedora GDB patches <invalid@email.com>
Date: Fri, 27 Oct 2017 21:07:50 +0200
Subject: gdb-6.6-buildid-locate.patch
;; New locating of the matching binaries from the pure core file (build-id).
;;=push+jan
diff --git a/gdb/build-id.c b/gdb/build-id.c
--- a/gdb/build-id.c
+++ b/gdb/build-id.c
@@ -24,9 +24,67 @@
#include "gdbsupport/gdb_vecs.h"
#include "symfile.h"
#include "objfiles.h"
+#include <sys/stat.h>
+#include "elf-bfd.h"
+#include "elf/common.h"
+#include "elf/external.h"
+#include "elf/internal.h"
#include "filenames.h"
+#include "gdb_bfd.h"
+#include "gdbcmd.h"
#include "gdbcore.h"
#include "cli/cli-style.h"
+#include "inferior.h"
+#include "objfiles.h"
+#include "observable.h"
+#include "symfile.h"
+
+#define BUILD_ID_VERBOSE_NONE 0
+#define BUILD_ID_VERBOSE_FILENAMES 1
+#define BUILD_ID_VERBOSE_BINARY_PARSE 2
+static int build_id_verbose = BUILD_ID_VERBOSE_FILENAMES;
+static void
+show_build_id_verbose (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ gdb_printf (file, _("Verbosity level of the build-id locator is %s.\n"),
+ value);
+}
+/* Locate NT_GNU_BUILD_ID and return its matching debug filename.
+ FIXME: NOTE decoding should be unified with the BFD core notes decoding. */
+
+static struct bfd_build_id *
+build_id_buf_get (bfd *templ, gdb_byte *buf, bfd_size_type size)
+{
+ bfd_byte *p;
+
+ p = buf;
+ while (p < buf + size)
+ {
+ /* FIXME: bad alignment assumption. */
+ Elf_External_Note *xnp = (Elf_External_Note *) p;
+ size_t namesz = H_GET_32 (templ, xnp->namesz);
+ size_t descsz = H_GET_32 (templ, xnp->descsz);
+ bfd_byte *descdata = (gdb_byte *) xnp->name + BFD_ALIGN (namesz, 4);
+
+ if (H_GET_32 (templ, xnp->type) == NT_GNU_BUILD_ID
+ && namesz == sizeof "GNU"
+ && memcmp (xnp->name, "GNU", sizeof "GNU") == 0)
+ {
+ size_t sz = descsz;
+ gdb_byte *data = (gdb_byte *) descdata;
+ struct bfd_build_id *retval;
+
+ retval = (struct bfd_build_id *) xmalloc (sizeof *retval - 1 + sz);
+ retval->size = sz;
+ memcpy (retval->data, data, sz);
+
+ return retval;
+ }
+ p = descdata + BFD_ALIGN (descsz, 4);
+ }
+ return NULL;
+}
/* See build-id.h. */
@@ -50,6 +108,348 @@ build_id_bfd_get (bfd *abfd)
return NULL;
}
+/* Core files may have missing (corrupt) SHDR but PDHR is correct there.
+ bfd_elf_bfd_from_remote_memory () has too much overhead by
+ allocating/reading all the available ELF PT_LOADs. */
+
+static struct bfd_build_id *
+build_id_phdr_get (bfd *templ, bfd_vma loadbase, unsigned e_phnum,
+ Elf_Internal_Phdr *i_phdr)
+{
+ int i;
+ struct bfd_build_id *retval = NULL;
+
+ for (i = 0; i < e_phnum; i++)
+ if (i_phdr[i].p_type == PT_NOTE && i_phdr[i].p_filesz > 0)
+ {
+ Elf_Internal_Phdr *hdr = &i_phdr[i];
+ gdb_byte *buf;
+ int err;
+
+ buf = (gdb_byte *) xmalloc (hdr->p_filesz);
+ err = target_read_memory (loadbase + i_phdr[i].p_vaddr, buf,
+ hdr->p_filesz);
+ if (err == 0)
+ retval = build_id_buf_get (templ, buf, hdr->p_filesz);
+ else
+ retval = NULL;
+ xfree (buf);
+ if (retval != NULL)
+ break;
+ }
+ return retval;
+}
+
+/* First we validate the file by reading in the ELF header and checking
+ the magic number. */
+
+static inline bfd_boolean
+elf_file_p (Elf64_External_Ehdr *x_ehdrp64)
+{
+ gdb_assert (sizeof (Elf64_External_Ehdr) >= sizeof (Elf32_External_Ehdr));
+ gdb_assert (offsetof (Elf64_External_Ehdr, e_ident)
+ == offsetof (Elf32_External_Ehdr, e_ident));
+ gdb_assert (sizeof (((Elf64_External_Ehdr *) 0)->e_ident)
+ == sizeof (((Elf32_External_Ehdr *) 0)->e_ident));
+
+ return ((x_ehdrp64->e_ident[EI_MAG0] == ELFMAG0)
+ && (x_ehdrp64->e_ident[EI_MAG1] == ELFMAG1)
+ && (x_ehdrp64->e_ident[EI_MAG2] == ELFMAG2)
+ && (x_ehdrp64->e_ident[EI_MAG3] == ELFMAG3));
+}
+
+/* Translate an ELF file header in external format into an ELF file header in
+ internal format. */
+
+#define H_GET_WORD(bfd, ptr) (is64 ? H_GET_64 (bfd, (ptr)) \
+ : H_GET_32 (bfd, (ptr)))
+#define H_GET_SIGNED_WORD(bfd, ptr) (is64 ? H_GET_S64 (bfd, (ptr)) \
+ : H_GET_S32 (bfd, (ptr)))
+
+static void
+elf_swap_ehdr_in (bfd *abfd,
+ const Elf64_External_Ehdr *src64,
+ Elf_Internal_Ehdr *dst)
+{
+ int is64 = bfd_get_arch_size (abfd) == 64;
+#define SRC(field) (is64 ? src64->field \
+ : ((const Elf32_External_Ehdr *) src64)->field)
+
+ int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma;
+ memcpy (dst->e_ident, SRC (e_ident), EI_NIDENT);
+ dst->e_type = H_GET_16 (abfd, SRC (e_type));
+ dst->e_machine = H_GET_16 (abfd, SRC (e_machine));
+ dst->e_version = H_GET_32 (abfd, SRC (e_version));
+ if (signed_vma)
+ dst->e_entry = H_GET_SIGNED_WORD (abfd, SRC (e_entry));
+ else
+ dst->e_entry = H_GET_WORD (abfd, SRC (e_entry));
+ dst->e_phoff = H_GET_WORD (abfd, SRC (e_phoff));
+ dst->e_shoff = H_GET_WORD (abfd, SRC (e_shoff));
+ dst->e_flags = H_GET_32 (abfd, SRC (e_flags));
+ dst->e_ehsize = H_GET_16 (abfd, SRC (e_ehsize));
+ dst->e_phentsize = H_GET_16 (abfd, SRC (e_phentsize));
+ dst->e_phnum = H_GET_16 (abfd, SRC (e_phnum));
+ dst->e_shentsize = H_GET_16 (abfd, SRC (e_shentsize));
+ dst->e_shnum = H_GET_16 (abfd, SRC (e_shnum));
+ dst->e_shstrndx = H_GET_16 (abfd, SRC (e_shstrndx));
+
+#undef SRC
+}
+
+/* Translate an ELF program header table entry in external format into an
+ ELF program header table entry in internal format. */
+
+static void
+elf_swap_phdr_in (bfd *abfd,
+ const Elf64_External_Phdr *src64,
+ Elf_Internal_Phdr *dst)
+{
+ int is64 = bfd_get_arch_size (abfd) == 64;
+#define SRC(field) (is64 ? src64->field \
+ : ((const Elf32_External_Phdr *) src64)->field)
+
+ int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma;
+
+ dst->p_type = H_GET_32 (abfd, SRC (p_type));
+ dst->p_flags = H_GET_32 (abfd, SRC (p_flags));
+ dst->p_offset = H_GET_WORD (abfd, SRC (p_offset));
+ if (signed_vma)
+ {
+ dst->p_vaddr = H_GET_SIGNED_WORD (abfd, SRC (p_vaddr));
+ dst->p_paddr = H_GET_SIGNED_WORD (abfd, SRC (p_paddr));
+ }
+ else
+ {
+ dst->p_vaddr = H_GET_WORD (abfd, SRC (p_vaddr));
+ dst->p_paddr = H_GET_WORD (abfd, SRC (p_paddr));
+ }
+ dst->p_filesz = H_GET_WORD (abfd, SRC (p_filesz));
+ dst->p_memsz = H_GET_WORD (abfd, SRC (p_memsz));
+ dst->p_align = H_GET_WORD (abfd, SRC (p_align));
+
+#undef SRC
+}
+
+#undef H_GET_SIGNED_WORD
+#undef H_GET_WORD
+
+static Elf_Internal_Phdr *
+elf_get_phdr (bfd *templ, bfd_vma ehdr_vma, unsigned *e_phnum_pointer,
+ bfd_vma *loadbase_pointer)
+{
+ /* sizeof (Elf64_External_Ehdr) >= sizeof (Elf32_External_Ehdr) */
+ Elf64_External_Ehdr x_ehdr64; /* Elf file header, external form */
+ Elf_Internal_Ehdr i_ehdr; /* Elf file header, internal form */
+ bfd_size_type x_phdrs_size;
+ gdb_byte *x_phdrs_ptr;
+ Elf_Internal_Phdr *i_phdrs;
+ int err;
+ unsigned int i;
+ bfd_vma loadbase;
+ int loadbase_set;
+
+ gdb_assert (templ != NULL);
+ gdb_assert (sizeof (Elf64_External_Ehdr) >= sizeof (Elf32_External_Ehdr));
+
+ /* Read in the ELF header in external format. */
+ err = target_read_memory (ehdr_vma, (bfd_byte *) &x_ehdr64, sizeof x_ehdr64);
+ if (err)
+ {
+ if (build_id_verbose >= BUILD_ID_VERBOSE_BINARY_PARSE)
+ warning (_("build-id: Error reading ELF header at address 0x%lx"),
+ (unsigned long) ehdr_vma);
+ return NULL;
+ }
+
+ /* Now check to see if we have a valid ELF file, and one that BFD can
+ make use of. The magic number must match, the address size ('class')
+ and byte-swapping must match our XVEC entry. */
+
+ if (! elf_file_p (&x_ehdr64)
+ || x_ehdr64.e_ident[EI_VERSION] != EV_CURRENT
+ || !((bfd_get_arch_size (templ) == 64
+ && x_ehdr64.e_ident[EI_CLASS] == ELFCLASS64)
+ || (bfd_get_arch_size (templ) == 32
+ && x_ehdr64.e_ident[EI_CLASS] == ELFCLASS32)))
+ {
+ if (build_id_verbose >= BUILD_ID_VERBOSE_BINARY_PARSE)
+ warning (_("build-id: Unrecognized ELF header at address 0x%lx"),
+ (unsigned long) ehdr_vma);
+ return NULL;
+ }
+
+ /* Check that file's byte order matches xvec's */
+ switch (x_ehdr64.e_ident[EI_DATA])
+ {
+ case ELFDATA2MSB: /* Big-endian */
+ if (! bfd_header_big_endian (templ))
+ {
+ if (build_id_verbose >= BUILD_ID_VERBOSE_BINARY_PARSE)
+ warning (_("build-id: Unrecognized "
+ "big-endian ELF header at address 0x%lx"),
+ (unsigned long) ehdr_vma);
+ return NULL;
+ }
+ break;
+ case ELFDATA2LSB: /* Little-endian */
+ if (! bfd_header_little_endian (templ))
+ {
+ if (build_id_verbose >= BUILD_ID_VERBOSE_BINARY_PARSE)
+ warning (_("build-id: Unrecognized "
+ "little-endian ELF header at address 0x%lx"),
+ (unsigned long) ehdr_vma);
+ return NULL;
+ }
+ break;
+ case ELFDATANONE: /* No data encoding specified */
+ default: /* Unknown data encoding specified */
+ if (build_id_verbose >= BUILD_ID_VERBOSE_BINARY_PARSE)
+ warning (_("build-id: Unrecognized "
+ "ELF header endianity at address 0x%lx"),
+ (unsigned long) ehdr_vma);
+ return NULL;
+ }
+
+ elf_swap_ehdr_in (templ, &x_ehdr64, &i_ehdr);
+
+ /* The file header tells where to find the program headers.
+ These are what we use to actually choose what to read. */
+
+ if (i_ehdr.e_phentsize != (bfd_get_arch_size (templ) == 64
+ ? sizeof (Elf64_External_Phdr)
+ : sizeof (Elf32_External_Phdr))
+ || i_ehdr.e_phnum == 0)
+ {
+ if (build_id_verbose >= BUILD_ID_VERBOSE_BINARY_PARSE)
+ warning (_("build-id: Invalid ELF program headers from the ELF header "
+ "at address 0x%lx"), (unsigned long) ehdr_vma);
+ return NULL;
+ }
+
+ x_phdrs_size = (bfd_get_arch_size (templ) == 64 ? sizeof (Elf64_External_Phdr)
+ : sizeof (Elf32_External_Phdr));
+
+ i_phdrs = (Elf_Internal_Phdr *) xmalloc (i_ehdr.e_phnum * (sizeof *i_phdrs + x_phdrs_size));
+ x_phdrs_ptr = (gdb_byte *) &i_phdrs[i_ehdr.e_phnum];
+ err = target_read_memory (ehdr_vma + i_ehdr.e_phoff, (bfd_byte *) x_phdrs_ptr,
+ i_ehdr.e_phnum * x_phdrs_size);
+ if (err)
+ {
+ free (i_phdrs);
+ if (build_id_verbose >= BUILD_ID_VERBOSE_BINARY_PARSE)
+ warning (_("build-id: Error reading "
+ "ELF program headers at address 0x%lx"),
+ (unsigned long) (ehdr_vma + i_ehdr.e_phoff));
+ return NULL;
+ }
+
+ loadbase = ehdr_vma;
+ loadbase_set = 0;
+ for (i = 0; i < i_ehdr.e_phnum; ++i)
+ {
+ elf_swap_phdr_in (templ, (Elf64_External_Phdr *)
+ (x_phdrs_ptr + i * x_phdrs_size), &i_phdrs[i]);
+ /* IA-64 vDSO may have two mappings for one segment, where one mapping
+ is executable only, and one is read only. We must not use the
+ executable one (PF_R is the first one, PF_X the second one). */
+ if (i_phdrs[i].p_type == PT_LOAD && (i_phdrs[i].p_flags & PF_R))
+ {
+ /* Only the first PT_LOAD segment indicates the file bias.
+ Next segments may have P_VADDR arbitrarily higher.
+ If the first segment has P_VADDR zero any next segment must not
+ confuse us, the first one sets LOADBASE certainly enough. */
+ if (!loadbase_set && i_phdrs[i].p_offset == 0)
+ {
+ loadbase = ehdr_vma - i_phdrs[i].p_vaddr;
+ loadbase_set = 1;
+ }
+ }
+ }
+
+ if (build_id_verbose >= BUILD_ID_VERBOSE_BINARY_PARSE)
+ warning (_("build-id: Found ELF header at address 0x%lx, loadbase 0x%lx"),
+ (unsigned long) ehdr_vma, (unsigned long) loadbase);
+
+ *e_phnum_pointer = i_ehdr.e_phnum;
+ *loadbase_pointer = loadbase;
+ return i_phdrs;
+}
+
+/* BUILD_ID_ADDR_GET gets ADDR located somewhere in the object.
+ Find the first section before ADDR containing an ELF header.
+ We rely on the fact the sections from multiple files do not mix.
+ FIXME: We should check ADDR is contained _inside_ the section with possibly
+ missing content (P_FILESZ < P_MEMSZ). These omitted sections are currently
+ hidden by _BFD_ELF_MAKE_SECTION_FROM_PHDR. */
+
+static CORE_ADDR build_id_addr;
+struct build_id_addr_sect
+ {
+ struct build_id_addr_sect *next;
+ asection *sect;
+ };
+static struct build_id_addr_sect *build_id_addr_sect;
+
+static void build_id_addr_candidate (bfd *abfd, asection *sect, void *obj)
+{
+ if (build_id_addr >= bfd_section_vma (sect))
+ {
+ struct build_id_addr_sect *candidate;
+
+ candidate = (struct build_id_addr_sect *) xmalloc (sizeof *candidate);
+ candidate->next = build_id_addr_sect;
+ build_id_addr_sect = candidate;
+ candidate->sect = sect;
+ }
+}
+
+struct bfd_build_id *
+build_id_addr_get (CORE_ADDR addr)
+{
+ struct build_id_addr_sect *candidate;
+ struct bfd_build_id *retval = NULL;
+ Elf_Internal_Phdr *i_phdr = NULL;
+ bfd_vma loadbase = 0;
+ unsigned e_phnum = 0;
+
+ if (core_bfd == NULL)
+ return NULL;
+
+ build_id_addr = addr;
+ gdb_assert (build_id_addr_sect == NULL);
+ bfd_map_over_sections (core_bfd, build_id_addr_candidate, NULL);
+
+ /* Sections are sorted in the high-to-low VMAs order.
+ Stop the search on the first ELF header we find.
+ Do not continue the search even if it does not contain NT_GNU_BUILD_ID. */
+
+ for (candidate = build_id_addr_sect; candidate != NULL;
+ candidate = candidate->next)
+ {
+ i_phdr = elf_get_phdr (core_bfd,
+ bfd_section_vma (candidate->sect),
+ &e_phnum, &loadbase);
+ if (i_phdr != NULL)
+ break;
+ }
+
+ if (i_phdr != NULL)
+ {
+ retval = build_id_phdr_get (core_bfd, loadbase, e_phnum, i_phdr);
+ xfree (i_phdr);
+ }
+
+ while (build_id_addr_sect != NULL)
+ {
+ candidate = build_id_addr_sect;
+ build_id_addr_sect = candidate->next;
+ xfree (candidate);
+ }
+
+ return retval;
+}
+
/* See build-id.h. */
int
@@ -73,63 +473,166 @@ build_id_verify (bfd *abfd, size_t check_len, const bfd_byte *check)
return retval;
}
+static char *
+link_resolve (const char *symlink, int level)
+{
+ char buf[PATH_MAX + 1], *retval;
+ gdb::unique_xmalloc_ptr<char> target;
+ ssize_t got;
+
+ if (level > 10)
+ return xstrdup (symlink);
+
+ got = readlink (symlink, buf, sizeof (buf));
+ if (got < 0 || got >= sizeof (buf))
+ return xstrdup (symlink);
+ buf[got] = '\0';
+
+ if (IS_ABSOLUTE_PATH (buf))
+ target = make_unique_xstrdup (buf);
+ else
+ {
+ const std::string dir (ldirname (symlink));
+
+ target = xstrprintf ("%s"
+#ifndef HAVE_DOS_BASED_FILE_SYSTEM
+ "/"
+#else /* HAVE_DOS_BASED_FILE_SYSTEM */
+ "\\"
+#endif /* HAVE_DOS_BASED_FILE_SYSTEM */
+ "%s", dir.c_str(), buf);
+ }
+
+ retval = link_resolve (target.get (), level + 1);
+ return retval;
+}
+
/* Helper for build_id_to_debug_bfd. LINK is a path to a potential
build-id-based separate debug file, potentially a symlink to the real file.
If the file exists and matches BUILD_ID, return a BFD reference to it. */
static gdb_bfd_ref_ptr
-build_id_to_debug_bfd_1 (const std::string &link, size_t build_id_len,
- const bfd_byte *build_id)
+build_id_to_debug_bfd_1 (const std::string &orig_link, size_t build_id_len,
+ const bfd_byte *build_id, char **link_return)
{
+ gdb_bfd_ref_ptr ret_bfd = {};
+ std::string ret_link;
+
if (separate_debug_file_debug)
{
- gdb_printf (gdb_stdlog, _(" Trying %s..."), link.c_str ());
- gdb_flush (gdb_stdlog);
+ gdb_printf (gdb_stdlog, _(" Trying %s..."), orig_link.c_str ());
+ gdb_flush (gdb_stdout);
}
- /* lrealpath() is expensive even for the usually non-existent files. */
- gdb::unique_xmalloc_ptr<char> filename_holder;
- const char *filename = nullptr;
- if (startswith (link, TARGET_SYSROOT_PREFIX))
- filename = link.c_str ();
- else if (access (link.c_str (), F_OK) == 0)
+ for (unsigned seqno = 0;; seqno++)
{
- filename_holder.reset (lrealpath (link.c_str ()));
- filename = filename_holder.get ();
- }
+ std::string link = orig_link;
- if (filename == NULL)
- {
- if (separate_debug_file_debug)
- gdb_printf (gdb_stdlog,
- _(" no, unable to compute real path\n"));
+ if (seqno > 0)
+ {
+ /* There can be multiple build-id symlinks pointing to real files
+ with the same build-id (such as hard links). Some of the real
+ files may not be installed. */
- return {};
- }
+ string_appendf (link, ".%u", seqno);
+ }
- /* We expect to be silent on the non-existing files. */
- gdb_bfd_ref_ptr debug_bfd = gdb_bfd_open (filename, gnutarget);
+ ret_link = link;
- if (debug_bfd == NULL)
- {
- if (separate_debug_file_debug)
- gdb_printf (gdb_stdlog, _(" no, unable to open.\n"));
+ struct stat statbuf_trash;
+
+ /* `access' automatically dereferences LINK. */
+ if (lstat (link.c_str (), &statbuf_trash) != 0)
+ {
+ /* Stop increasing SEQNO. */
+ break;
+ }
+
+ /* lrealpath() is expensive even for the usually non-existent files. */
+ gdb::unique_xmalloc_ptr<char> filename_holder;
+ const char *filename = nullptr;
+ if (startswith (link, TARGET_SYSROOT_PREFIX))
+ filename = link.c_str ();
+ else if (access (link.c_str (), F_OK) == 0)
+ {
+ filename_holder.reset (lrealpath (link.c_str ()));
+ filename = filename_holder.get ();
+ }
+
+ if (filename == NULL)
+ {
+ if (separate_debug_file_debug)
+ gdb_printf (gdb_stdlog,
+ _(" no, unable to compute real path\n"));
+
+ continue;
+ }
+
+ /* We expect to be silent on the non-existing files. */
+ gdb_bfd_ref_ptr debug_bfd = gdb_bfd_open (filename, gnutarget);
- return {};
+ if (debug_bfd == NULL)
+ {
+ if (separate_debug_file_debug)
+ gdb_printf (gdb_stdlog, _(" no, unable to open.\n"));
+
+ continue;
+ }
+
+ if (!build_id_verify (debug_bfd.get(), build_id_len, build_id))
+ {
+ if (separate_debug_file_debug)
+ gdb_printf (gdb_stdlog,
+ _(" no, build-id does not match.\n"));
+
+ continue;
+ }
+
+ ret_bfd = debug_bfd;
+ break;
}
- if (!build_id_verify (debug_bfd.get(), build_id_len, build_id))
+ std::string link_all;
+
+ if (ret_bfd != NULL)
{
if (separate_debug_file_debug)
- gdb_printf (gdb_stdlog, _(" no, build-id does not match.\n"));
-
- return {};
+ gdb_printf (gdb_stdlog, _(" yes!\n"));
+ }
+ else
+ {
+ /* If none of the real files is found report as missing file
+ always the non-.%u-suffixed file. */
+ std::string link0 = orig_link;
+
+ /* If the symlink has target request to install the target.
+ BASE-debuginfo.rpm contains the symlink but BASE.rpm may be missing.
+ https://bugzilla.redhat.com/show_bug.cgi?id=981154 */
+ std::string link0_resolved (link_resolve (link0.c_str (), 0));
+
+ if (link_all.empty ())
+ link_all = link0_resolved;
+ else
+ {
+ /* Use whitespace instead of DIRNAME_SEPARATOR to be compatible with
+ its possible use as an argument for installation command. */
+ link_all += " " + link0_resolved;
+ }
}
- if (separate_debug_file_debug)
- gdb_printf (gdb_stdlog, _(" yes!\n"));
+ if (link_return != NULL)
+ {
+ if (ret_bfd != NULL)
+ {
+ *link_return = xstrdup (ret_link.c_str ());
+ }
+ else
+ {
+ *link_return = xstrdup (link_all.c_str ());
+ }
+ }
- return debug_bfd;
+ return ret_bfd;
}
/* Common code for finding BFDs of a given build-id. This function
@@ -138,7 +641,7 @@ build_id_to_debug_bfd_1 (const std::string &link, size_t build_id_len,
static gdb_bfd_ref_ptr
build_id_to_bfd_suffix (size_t build_id_len, const bfd_byte *build_id,
- const char *suffix)
+ const char *suffix, char **link_return)
{
/* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
cause "/.build-id/..." lookups. */
@@ -161,16 +664,17 @@ build_id_to_bfd_suffix (size_t build_id_len, const bfd_byte *build_id,
if (size > 0)
{
size--;
- string_appendf (link, "%02x/", (unsigned) *data++);
+ string_appendf (link, "%02x", (unsigned) *data++);
}
-
+ if (size > 0)
+ link += "/";
while (size-- > 0)
string_appendf (link, "%02x", (unsigned) *data++);
link += suffix;
gdb_bfd_ref_ptr debug_bfd
- = build_id_to_debug_bfd_1 (link, build_id_len, build_id);
+ = build_id_to_debug_bfd_1 (link, build_id_len, build_id, link_return);
if (debug_bfd != NULL)
return debug_bfd;
@@ -181,7 +685,7 @@ build_id_to_bfd_suffix (size_t build_id_len, const bfd_byte *build_id,
if (!gdb_sysroot.empty ())
{
link = gdb_sysroot + link;
- debug_bfd = build_id_to_debug_bfd_1 (link, build_id_len, build_id);
+ debug_bfd = build_id_to_debug_bfd_1 (link, build_id_len, build_id, NULL);
if (debug_bfd != NULL)
return debug_bfd;
}
@@ -190,20 +694,178 @@ build_id_to_bfd_suffix (size_t build_id_len, const bfd_byte *build_id,
return {};
}
+char *
+build_id_to_filename (const struct bfd_build_id *build_id, char **link_return)
+{
+ gdb_bfd_ref_ptr abfd;
+ char *result;
+
+ abfd = build_id_to_exec_bfd (build_id->size, build_id->data, link_return);
+ if (abfd == NULL)
+ return NULL;
+
+ result = xstrdup (bfd_get_filename (abfd.get ()));
+ return result;
+}
+
+/* This MISSING_FILEPAIR_HASH tracker is used only for the duplicite messages
+ yum --enablerepo='*debug*' install ...
+ avoidance. */
+
+struct missing_filepair
+ {
+ char *binary;
+ char *debug;
+ char data[1];
+ };
+
+static struct htab *missing_filepair_hash;
+static struct obstack missing_filepair_obstack;
+
+static void *
+missing_filepair_xcalloc (size_t nmemb, size_t nmemb_size)
+{
+ void *retval;
+ size_t size = nmemb * nmemb_size;
+
+ retval = obstack_alloc (&missing_filepair_obstack, size);
+ memset (retval, 0, size);
+ return retval;
+}
+
+static hashval_t
+missing_filepair_hash_func (const struct missing_filepair *elem)
+{
+ hashval_t retval = 0;
+
+ retval ^= htab_hash_string (elem->binary);
+ if (elem->debug != NULL)
+ retval ^= htab_hash_string (elem->debug);
+
+ return retval;
+}
+
+static int
+missing_filepair_eq (const struct missing_filepair *elem1,
+ const struct missing_filepair *elem2)
+{
+ return strcmp (elem1->binary, elem2->binary) == 0
+ && ((elem1->debug == NULL) == (elem2->debug == NULL))
+ && (elem1->debug == NULL || strcmp (elem1->debug, elem2->debug) == 0);
+}
+
+static void
+missing_filepair_change (void)
+{
+ if (missing_filepair_hash != NULL)
+ {
+ obstack_free (&missing_filepair_obstack, NULL);
+ /* All their memory came just from missing_filepair_OBSTACK. */
+ missing_filepair_hash = NULL;
+ }
+}
+
+static void
+debug_print_executable_changed (struct program_space *pspace, bool reload_p)
+{
+ missing_filepair_change ();
+}
+
+/* Notify user the file BINARY with (possibly NULL) associated separate debug
+ information file DEBUG is missing. DEBUG may or may not be the build-id
+ file such as would be:
+ /usr/lib/debug/.build-id/dd/b1d2ce632721c47bb9e8679f369e2295ce71be.debug
+ */
+
+void
+debug_print_missing (const char *binary, const char *debug)
+{
+ size_t binary_len0 = strlen (binary) + 1;
+ size_t debug_len0 = debug ? strlen (debug) + 1 : 0;
+ struct missing_filepair missing_filepair_find;
+ struct missing_filepair *missing_filepair;
+ struct missing_filepair **slot;
+
+ if (build_id_verbose < BUILD_ID_VERBOSE_FILENAMES)
+ return;
+
+ if (missing_filepair_hash == NULL)
+ {
+ obstack_init (&missing_filepair_obstack);
+ missing_filepair_hash = htab_create_alloc (64,
+ (hashval_t (*) (const void *)) missing_filepair_hash_func,
+ (int (*) (const void *, const void *)) missing_filepair_eq, NULL,
+ missing_filepair_xcalloc, NULL);
+ }
+
+ /* Use MISSING_FILEPAIR_FIND first instead of calling obstack_alloc with
+ obstack_free in the case of a (rare) match. The problem is ALLOC_F for
+ MISSING_FILEPAIR_HASH allocates from MISSING_FILEPAIR_OBSTACK maintenance
+ structures for MISSING_FILEPAIR_HASH. Calling obstack_free would possibly
+ not to free only MISSING_FILEPAIR but also some such structures (allocated
+ during the htab_find_slot call). */
+
+ missing_filepair_find.binary = (char *) binary;
+ missing_filepair_find.debug = (char *) debug;
+ slot = (struct missing_filepair **) htab_find_slot (missing_filepair_hash,
+ &missing_filepair_find,
+ INSERT);
+
+ /* While it may be still printed duplicitely with the missing debuginfo file
+ * it is due to once printing about the binary file build-id link and once
+ * about the .debug file build-id link as both the build-id symlinks are
+ * located in the debuginfo package. */
+
+ if (*slot != NULL)
+ return;
+
+ missing_filepair = (struct missing_filepair *) obstack_alloc (&missing_filepair_obstack,
+ sizeof (*missing_filepair) - 1
+ + binary_len0 + debug_len0);
+ missing_filepair->binary = missing_filepair->data;
+ memcpy (missing_filepair->binary, binary, binary_len0);
+ if (debug != NULL)
+ {
+ missing_filepair->debug = missing_filepair->binary + binary_len0;
+ memcpy (missing_filepair->debug, debug, debug_len0);
+ }
+ else
+ missing_filepair->debug = NULL;
+
+ *slot = missing_filepair;
+
+ /* We do not collect and flush these messages as each such message
+ already requires its own separate lines. */
+
+ gdb_printf (gdb_stdlog,
+ _("Missing separate debuginfo for %s.\n"), binary);
+ if (debug != NULL)
+ {
+ gdb_printf (gdb_stdlog, _("Try: %s %s\n"),
+#ifdef DNF_DEBUGINFO_INSTALL
+ "dnf"
+#else
+ "yum"
+#endif
+ " --enablerepo='*debug*' install", debug);
+ }
+}
+
/* See build-id.h. */
gdb_bfd_ref_ptr
build_id_to_debug_bfd (size_t build_id_len, const bfd_byte *build_id)
{
- return build_id_to_bfd_suffix (build_id_len, build_id, ".debug");
+ return build_id_to_bfd_suffix (build_id_len, build_id, ".debug", nullptr);
}
/* See build-id.h. */
gdb_bfd_ref_ptr
-build_id_to_exec_bfd (size_t build_id_len, const bfd_byte *build_id)
+build_id_to_exec_bfd (size_t build_id_len, const bfd_byte *build_id,
+ char **link_return)
{
- return build_id_to_bfd_suffix (build_id_len, build_id, "");
+ return build_id_to_bfd_suffix (build_id_len, build_id, "", link_return);
}
/* See build-id.h. */
@@ -224,6 +886,7 @@ find_separate_debug_file_by_buildid (struct objfile *objfile,
gdb_bfd_ref_ptr abfd (build_id_to_debug_bfd (build_id->size,
build_id->data));
+
/* Prevent looping on a stripped .debug file. */
if (abfd != NULL
&& filename_cmp (bfd_get_filename (abfd.get ()),
@@ -243,3 +906,22 @@ find_separate_debug_file_by_buildid (struct objfile *objfile,
return std::string ();
}
+
+void _initialize_build_id ();
+
+void
+_initialize_build_id ()
+{
+ add_setshow_zinteger_cmd ("build-id-verbose", no_class, &build_id_verbose,
+ _("\
+Set debugging level of the build-id locator."), _("\
+Show debugging level of the build-id locator."), _("\
+Level 1 (default) enables printing the missing debug filenames,\n\
+level 2 also prints the parsing of binaries to find the identificators."),
+ NULL,
+ show_build_id_verbose,
+ &setlist, &showlist);
+
+ gdb::observers::executable_changed.attach (debug_print_executable_changed,
+ "build-id");
+}
diff --git a/gdb/build-id.h b/gdb/build-id.h
--- a/gdb/build-id.h
+++ b/gdb/build-id.h
@@ -40,12 +40,16 @@ extern int build_id_verify (bfd *abfd,
extern gdb_bfd_ref_ptr build_id_to_debug_bfd (size_t build_id_len,
const bfd_byte *build_id);
+extern char *build_id_to_filename (const struct bfd_build_id *build_id,
+ char **link_return);
+
/* Find and open a BFD for an executable file given a build-id. If no BFD
can be found, return NULL. The returned reference to the BFD must be
released by the caller. */
extern gdb_bfd_ref_ptr build_id_to_exec_bfd (size_t build_id_len,
- const bfd_byte *build_id);
+ const bfd_byte *build_id,
+ char **link_return);
/* Find the separate debug file for OBJFILE, by using the build-id
associated with OBJFILE's BFD. If successful, returns the file name for the
diff --git a/gdb/corelow.c b/gdb/corelow.c
--- a/gdb/corelow.c
+++ b/gdb/corelow.c
@@ -22,6 +22,10 @@
#include <signal.h>
#include <fcntl.h>
#include "frame.h"
+#include "auxv.h"
+#include "build-id.h"
+#include "elf/common.h"
+#include "gdbcmd.h"
#include "inferior.h"
#include "infrun.h"
#include "symtab.h"
@@ -380,6 +384,8 @@ add_to_thread_list (asection *asect, asection *reg_sect, inferior *inf)
switch_to_thread (thr); /* Yes, make it current. */
}
+static bool build_id_core_loads = true;
+
/* Issue a message saying we have no core to debug, if FROM_TTY. */
static void
@@ -567,8 +573,10 @@ locate_exec_from_corefile_build_id (bfd *abfd, int from_tty)
if (build_id == nullptr)
return;
+ char *build_id_filename;
gdb_bfd_ref_ptr execbfd
- = build_id_to_exec_bfd (build_id->size, build_id->data);
+ = build_id_to_exec_bfd (build_id->size, build_id->data,
+ &build_id_filename);
if (execbfd == nullptr)
{
@@ -596,7 +604,12 @@ locate_exec_from_corefile_build_id (bfd *abfd, int from_tty)
exec_file_attach (bfd_get_filename (execbfd.get ()), from_tty);
symbol_file_add_main (bfd_get_filename (execbfd.get ()),
symfile_add_flag (from_tty ? SYMFILE_VERBOSE : 0));
+ if (current_program_space->symfile_object_file != NULL)
+ current_program_space->symfile_object_file->flags |=
+ OBJF_BUILD_ID_CORE_LOADED;
}
+ else
+ debug_print_missing (BUILD_ID_MAIN_EXECUTABLE_FILENAME, build_id_filename);
}
/* See gdbcore.h. */
@@ -1506,4 +1519,11 @@ _initialize_corelow ()
maintenance_print_core_file_backed_mappings,
_("Print core file's file-backed mappings."),
&maintenanceprintlist);
+
+ add_setshow_boolean_cmd ("build-id-core-loads", class_files,
+ &build_id_core_loads, _("\
+Set whether CORE-FILE loads the build-id associated files automatically."), _("\
+Show whether CORE-FILE loads the build-id associated files automatically."),
+ NULL, NULL, NULL,
+ &setlist, &showlist);
}
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -22296,6 +22296,27 @@ information files.
@end table
+You can also adjust the current verbosity of the @dfn{build id} locating.
+
+@table @code
+
+@kindex set build-id-verbose
+@item set build-id-verbose 0
+No additional messages are printed.
+
+@item set build-id-verbose 1
+Missing separate debug filenames are printed.
+
+@item set build-id-verbose 2
+Missing separate debug filenames are printed and also all the parsing of the
+binaries to find their @dfn{build id} content is printed.
+
+@kindex show build-id-verbose
+@item show build-id-verbose
+Show the current verbosity value for the @dfn{build id} content locating.
+
+@end table
+
@cindex @code{.gnu_debuglink} sections
@cindex debug link sections
A debug link is a special section of the executable file named
diff --git a/gdb/objfiles.h b/gdb/objfiles.h
--- a/gdb/objfiles.h
+++ b/gdb/objfiles.h
@@ -884,6 +884,10 @@ struct objfile
bool object_format_has_copy_relocs = false;
};
+/* This file was loaded according to the BUILD_ID_CORE_LOADS rules. */
+
+#define OBJF_BUILD_ID_CORE_LOADED static_cast<enum objfile_flag>(1 << 12)
+
/* A deleter for objfile. */
struct objfile_deleter
diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c
--- a/gdb/solib-svr4.c
+++ b/gdb/solib-svr4.c
@@ -44,6 +44,7 @@
#include "auxv.h"
#include "gdb_bfd.h"
#include "probe.h"
+#include "build-id.h"
#include <map>
@@ -1318,9 +1319,51 @@ svr4_read_so_list (svr4_info *info, CORE_ADDR lm, CORE_ADDR prev_lm,
continue;
}
- strncpy (newobj->so_name, buffer.get (), SO_NAME_MAX_PATH_SIZE - 1);
- newobj->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
- strcpy (newobj->so_original_name, newobj->so_name);
+ {
+ struct bfd_build_id *build_id;
+
+ strncpy (newobj->so_original_name, buffer.get (), SO_NAME_MAX_PATH_SIZE - 1);
+ newobj->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
+ /* May get overwritten below. */
+ strcpy (newobj->so_name, newobj->so_original_name);
+
+ build_id = build_id_addr_get (((lm_info_svr4 *) newobj->lm_info)->l_ld);
+ if (build_id != NULL)
+ {
+ char *name, *build_id_filename;
+
+ /* Missing the build-id matching separate debug info file
+ would be handled while SO_NAME gets loaded. */
+ name = build_id_to_filename (build_id, &build_id_filename);
+ if (name != NULL)
+ {
+ strncpy (newobj->so_name, name, SO_NAME_MAX_PATH_SIZE - 1);
+ newobj->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
+ xfree (name);
+ }
+ else
+ {
+ debug_print_missing (newobj->so_name, build_id_filename);
+
+ /* In the case the main executable was found according to
+ its build-id (from a core file) prevent loading
+ a different build of a library with accidentally the
+ same SO_NAME.
+
+ It suppresses bogus backtraces (and prints "??" there
+ instead) if the on-disk files no longer match the
+ running program version. */
+
+ if (current_program_space->symfile_object_file != NULL
+ && (current_program_space->symfile_object_file->flags
+ & OBJF_BUILD_ID_CORE_LOADED) != 0)
+ newobj->so_name[0] = 0;
+ }
+
+ xfree (build_id_filename);
+ xfree (build_id);
+ }
+ }
/* If this entry has no name, or its name matches the name
for the main executable, don't include it in the list. */
diff --git a/gdb/symfile.h b/gdb/symfile.h
--- a/gdb/symfile.h
+++ b/gdb/symfile.h
@@ -363,6 +363,11 @@ void map_symbol_filenames (gdb::function_view<symbol_filename_ftype> fun,
optional offset to apply to each section. */
extern void generic_load (const char *args, int from_tty);
+/* build-id support. */
+extern struct bfd_build_id *build_id_addr_get (CORE_ADDR addr);
+extern void debug_print_missing (const char *binary, const char *debug);
+#define BUILD_ID_MAIN_EXECUTABLE_FILENAME _("the main executable file")
+
/* From minidebug.c. */
extern gdb_bfd_ref_ptr find_separate_debug_file_in_section (struct objfile *);
diff --git a/gdb/testsuite/gdb.base/corefile.exp b/gdb/testsuite/gdb.base/corefile.exp
--- a/gdb/testsuite/gdb.base/corefile.exp
+++ b/gdb/testsuite/gdb.base/corefile.exp
@@ -347,3 +347,33 @@ gdb_test_multiple "core-file $corefile" $test {
pass $test
}
}
+
+
+# Test auto-loading of binary files through build-id from the core file.
+set buildid [build_id_debug_filename_get $binfile]
+set wholetest "binfile found by build-id"
+if {$buildid == ""} {
+ untested "$wholetest (binary has no build-id)"
+} else {
+ gdb_exit
+ gdb_start
+
+ regsub {\.debug$} $buildid {} buildid
+ set debugdir [standard_output_file ${testfile}-debugdir]
+ file delete -force -- $debugdir
+ file mkdir $debugdir/[file dirname $buildid]
+ file copy $binfile $debugdir/$buildid
+
+ set test "show debug-file-directory"
+ gdb_test_multiple $test $test {
+ -re "The directory where separate debug symbols are searched for is \"(.*)\"\\.\r\n$gdb_prompt $" {
+ set debugdir_orig $expect_out(1,string)
+ pass $test
+ }
+ }
+ gdb_test_no_output "set debug-file-directory $debugdir:$debugdir_orig" "set debug-file-directory"
+ gdb_test "show build-id-core-loads" {Whether CORE-FILE loads the build-id associated files automatically is on\.}
+ gdb_test "core-file $corefile" "\r\nProgram terminated with .*" "core-file without executable"
+ gdb_test "info files" "Local exec file:\r\n\[ \t\]*`[string_to_regexp $debugdir/$buildid]', file type .*"
+ pass $wholetest
+}
diff --git a/gdb/testsuite/gdb.base/gdbinit-history.exp b/gdb/testsuite/gdb.base/gdbinit-history.exp
--- a/gdb/testsuite/gdb.base/gdbinit-history.exp
+++ b/gdb/testsuite/gdb.base/gdbinit-history.exp
@@ -179,7 +179,8 @@ proc test_empty_history_filename { } {
global env
global gdb_prompt
- set common_history [list "set height 0" "set width 0"]
+ set common_history [list "set height 0" "set width 0" \
+ "set build-id-verbose 0"]
set test_dir [standard_output_file history_test]
remote_exec host "mkdir -p $test_dir"
diff --git a/gdb/testsuite/gdb.base/new-ui-pending-input.exp b/gdb/testsuite/gdb.base/new-ui-pending-input.exp
--- a/gdb/testsuite/gdb.base/new-ui-pending-input.exp
+++ b/gdb/testsuite/gdb.base/new-ui-pending-input.exp
@@ -62,6 +62,7 @@ proc test_command_line_new_ui_pending_input {} {
set options ""
append options " -iex \"set height 0\""
append options " -iex \"set width 0\""
+ append options " -iex \"set build-id-verbose 0\""
append options " -iex \"new-ui console $extra_tty_name\""
append options " -ex \"b $bpline\""
append options " -ex \"run\""
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -226,7 +226,8 @@ if ![info exists INTERNAL_GDBFLAGS] {
"-nx" \
"-q" \
{-iex "set height 0"} \
- {-iex "set width 0"}]]
+ {-iex "set width 0"} \
+ {-iex "set build-id-verbose 0"}]]
# If DEBUGINFOD_URLS is set, gdb will try to download sources and
# debug info for f.i. system libraries. Prevent this.
@@ -2434,6 +2435,17 @@ proc default_gdb_start { } {
}
}
+ # Turn off the missing warnings as the testsuite does not expect it.
+ send_gdb "set build-id-verbose 0\n"
+ gdb_expect 10 {
+ -re "$gdb_prompt $" {
+ verbose "Disabled the missing debug infos warnings." 2
+ }
+ timeout {
+ warning "Could not disable the missing debug infos warnings.."
+ }
+ }
+
gdb_debug_init
return 0
}
diff --git a/gdb/testsuite/lib/mi-support.exp b/gdb/testsuite/lib/mi-support.exp
--- a/gdb/testsuite/lib/mi-support.exp
+++ b/gdb/testsuite/lib/mi-support.exp
@@ -321,6 +321,16 @@ proc default_mi_gdb_start { { flags {} } } {
warning "Couldn't set the width to 0."
}
}
+ # Turn off the missing warnings as the testsuite does not expect it.
+ send_gdb "190-gdb-set build-id-verbose 0\n"
+ gdb_expect 10 {
+ -re ".*190-gdb-set build-id-verbose 0\r\n190\\\^done\r\n$mi_gdb_prompt$" {
+ verbose "Disabled the missing debug infos warnings." 2
+ }
+ timeout {
+ warning "Could not disable the missing debug infos warnings.."
+ }
+ }
if { $separate_inferior_pty } {
mi_create_inferior_pty