/* Handle SVR4 shared libraries for GDB, the GNU Debugger.
- Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999,
- 2000, 2001, 2003, 2004, 2005
+ Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000,
+ 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "gdbcore.h"
#include "target.h"
#include "inferior.h"
+#include "regcache.h"
+#include "gdbthread.h"
+#include "observer.h"
#include "gdb_assert.h"
#include "solist.h"
+#include "solib.h"
#include "solib-svr4.h"
#include "bfd-target.h"
+#include "elf-bfd.h"
#include "exec.h"
+#include "auxv.h"
+#include "exceptions.h"
static struct link_map_offsets *svr4_fetch_link_map_offsets (void);
static int svr4_have_link_map_offsets (void);
+static void svr4_relocate_main_executable (void);
-/* This hook is set to a function that provides native link map
- offsets if the code in solib-legacy.c is linked in. */
-struct link_map_offsets *(*legacy_svr4_fetch_link_map_offsets_hook) (void);
-
-/* Link map info to include in an allocated so_list entry */
+/* Link map info to include in an allocated so_list entry. */
struct lm_info
{
rather than void *, so that we may use byte offsets to find the
various fields without the need for a cast. */
gdb_byte *lm;
+
+ /* Amount by which addresses in the binary should be relocated to
+ match the inferior. This could most often be taken directly
+ from lm, but when prelinking is involved and the prelink base
+ address changes, we may need a different offset, we want to
+ warn about the difference and compute it only once. */
+ CORE_ADDR l_addr;
+
+ /* The target location of lm. */
+ CORE_ADDR lm_addr;
};
/* On SVR4 systems, a list of symbols in the dynamic linker where
SVR4 systems will fall back to using a symbol as the "startup
mapping complete" breakpoint address. */
-static char *solib_break_names[] =
+static const char * const solib_break_names[] =
{
"r_debug_state",
"_r_debug_state",
"_dl_debug_state",
"rtld_db_dlactivity",
+ "__dl_rtld_db_dlactivity",
"_rtld_debug_state",
- /* On the 64-bit PowerPC, the linker symbol with the same name as
- the C function points to a function descriptor, not to the entry
- point. The linker symbol whose name is the C function name
- prefixed with a '.' points to the function's entry point. So
- when we look through this table, we ignore symbols that point
- into the data section (thus skipping the descriptor's symbol),
- and eventually try this one, giving us the real entry point
- address. */
- "._dl_debug_state",
-
NULL
};
-#define BKPT_AT_SYMBOL 1
-
-#if defined (BKPT_AT_SYMBOL)
-static char *bkpt_names[] =
+static const char * const bkpt_names[] =
{
-#ifdef SOLIB_BKPT_NAME
- SOLIB_BKPT_NAME, /* Prefer configured name if it exists. */
-#endif
"_start",
"__start",
"main",
NULL
};
-#endif
-static char *main_name_list[] =
+static const char * const main_name_list[] =
{
"main_$main",
NULL
};
-/* Macro to extract an address from a solib structure. When GDB is
- configured for some 32-bit targets (e.g. Solaris 2.7 sparc), BFD is
- configured to handle 64-bit targets, so CORE_ADDR is 64 bits. We
- have to extract only the significant bits of addresses to get the
- right address when accessing the core file BFD.
+/* Return non-zero if GDB_SO_NAME and INFERIOR_SO_NAME represent
+ the same shared library. */
+
+static int
+svr4_same_1 (const char *gdb_so_name, const char *inferior_so_name)
+{
+ if (strcmp (gdb_so_name, inferior_so_name) == 0)
+ return 1;
+
+ /* On Solaris, when starting inferior we think that dynamic linker is
+ /usr/lib/ld.so.1, but later on, the table of loaded shared libraries
+ contains /lib/ld.so.1. Sometimes one file is a link to another, but
+ sometimes they have identical content, but are not linked to each
+ other. We don't restrict this check for Solaris, but the chances
+ of running into this situation elsewhere are very low. */
+ if (strcmp (gdb_so_name, "/usr/lib/ld.so.1") == 0
+ && strcmp (inferior_so_name, "/lib/ld.so.1") == 0)
+ return 1;
+
+ /* Similarly, we observed the same issue with sparc64, but with
+ different locations. */
+ if (strcmp (gdb_so_name, "/usr/lib/sparcv9/ld.so.1") == 0
+ && strcmp (inferior_so_name, "/lib/sparcv9/ld.so.1") == 0)
+ return 1;
+
+ return 0;
+}
+
+static int
+svr4_same (struct so_list *gdb, struct so_list *inferior)
+{
+ return (svr4_same_1 (gdb->so_original_name, inferior->so_original_name));
+}
+
+/* link map access functions. */
- Assume that the address is unsigned. */
+static CORE_ADDR
+LM_ADDR_FROM_LINK_MAP (struct so_list *so)
+{
+ struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
+ struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
-#define SOLIB_EXTRACT_ADDRESS(MEMBER) \
- extract_unsigned_integer (&(MEMBER), sizeof (MEMBER))
+ return extract_typed_address (so->lm_info->lm + lmo->l_addr_offset,
+ ptr_type);
+}
-/* local data declarations */
+static int
+HAS_LM_DYNAMIC_FROM_LINK_MAP (void)
+{
+ struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
-/* link map access functions */
+ return lmo->l_ld_offset >= 0;
+}
static CORE_ADDR
-LM_ADDR (struct so_list *so)
+LM_DYNAMIC_FROM_LINK_MAP (struct so_list *so)
{
struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
+ struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
+
+ return extract_typed_address (so->lm_info->lm + lmo->l_ld_offset,
+ ptr_type);
+}
+
+static CORE_ADDR
+LM_ADDR_CHECK (struct so_list *so, bfd *abfd)
+{
+ if (so->lm_info->l_addr == (CORE_ADDR)-1)
+ {
+ struct bfd_section *dyninfo_sect;
+ CORE_ADDR l_addr, l_dynaddr, dynaddr;
+
+ l_addr = LM_ADDR_FROM_LINK_MAP (so);
+
+ if (! abfd || ! HAS_LM_DYNAMIC_FROM_LINK_MAP ())
+ goto set_addr;
+
+ l_dynaddr = LM_DYNAMIC_FROM_LINK_MAP (so);
+
+ dyninfo_sect = bfd_get_section_by_name (abfd, ".dynamic");
+ if (dyninfo_sect == NULL)
+ goto set_addr;
+
+ dynaddr = bfd_section_vma (abfd, dyninfo_sect);
+
+ if (dynaddr + l_addr != l_dynaddr)
+ {
+ CORE_ADDR align = 0x1000;
+ CORE_ADDR minpagesize = align;
+
+ if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
+ {
+ Elf_Internal_Ehdr *ehdr = elf_tdata (abfd)->elf_header;
+ Elf_Internal_Phdr *phdr = elf_tdata (abfd)->phdr;
+ int i;
+
+ align = 1;
+
+ for (i = 0; i < ehdr->e_phnum; i++)
+ if (phdr[i].p_type == PT_LOAD && phdr[i].p_align > align)
+ align = phdr[i].p_align;
+
+ minpagesize = get_elf_backend_data (abfd)->minpagesize;
+ }
+
+ /* Turn it into a mask. */
+ align--;
+
+ /* If the changes match the alignment requirements, we
+ assume we're using a core file that was generated by the
+ same binary, just prelinked with a different base offset.
+ If it doesn't match, we may have a different binary, the
+ same binary with the dynamic table loaded at an unrelated
+ location, or anything, really. To avoid regressions,
+ don't adjust the base offset in the latter case, although
+ odds are that, if things really changed, debugging won't
+ quite work.
+
+ One could expect more the condition
+ ((l_addr & align) == 0 && ((l_dynaddr - dynaddr) & align) == 0)
+ but the one below is relaxed for PPC. The PPC kernel supports
+ either 4k or 64k page sizes. To be prepared for 64k pages,
+ PPC ELF files are built using an alignment requirement of 64k.
+ However, when running on a kernel supporting 4k pages, the memory
+ mapping of the library may not actually happen on a 64k boundary!
+
+ (In the usual case where (l_addr & align) == 0, this check is
+ equivalent to the possibly expected check above.)
+
+ Even on PPC it must be zero-aligned at least for MINPAGESIZE. */
+
+ if ((l_addr & (minpagesize - 1)) == 0
+ && (l_addr & align) == ((l_dynaddr - dynaddr) & align))
+ {
+ l_addr = l_dynaddr - dynaddr;
+
+ if (info_verbose)
+ printf_unfiltered (_("Using PIC (Position Independent Code) "
+ "prelink displacement %s for \"%s\".\n"),
+ paddress (target_gdbarch, l_addr),
+ so->so_name);
+ }
+ else
+ warning (_(".dynamic section for \"%s\" "
+ "is not at the expected address "
+ "(wrong library or version mismatch?)"), so->so_name);
+ }
+
+ set_addr:
+ so->lm_info->l_addr = l_addr;
+ }
- return (CORE_ADDR) extract_signed_integer (so->lm_info->lm + lmo->l_addr_offset,
- lmo->l_addr_size);
+ return so->lm_info->l_addr;
}
static CORE_ADDR
LM_NEXT (struct so_list *so)
{
struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
+ struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
- /* Assume that the address is unsigned. */
- return extract_unsigned_integer (so->lm_info->lm + lmo->l_next_offset,
- lmo->l_next_size);
+ return extract_typed_address (so->lm_info->lm + lmo->l_next_offset,
+ ptr_type);
+}
+
+static CORE_ADDR
+LM_PREV (struct so_list *so)
+{
+ struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
+ struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
+
+ return extract_typed_address (so->lm_info->lm + lmo->l_prev_offset,
+ ptr_type);
}
static CORE_ADDR
LM_NAME (struct so_list *so)
{
struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
+ struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
- /* Assume that the address is unsigned. */
- return extract_unsigned_integer (so->lm_info->lm + lmo->l_name_offset,
- lmo->l_name_size);
+ return extract_typed_address (so->lm_info->lm + lmo->l_name_offset,
+ ptr_type);
}
static int
IGNORE_FIRST_LINK_MAP_ENTRY (struct so_list *so)
{
- struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
+ /* Assume that everything is a library if the dynamic loader was loaded
+ late by a static executable. */
+ if (exec_bfd && bfd_get_section_by_name (exec_bfd, ".dynamic") == NULL)
+ return 0;
- /* Assume that the address is unsigned. */
- return extract_unsigned_integer (so->lm_info->lm + lmo->l_prev_offset,
- lmo->l_prev_size) == 0;
+ return LM_PREV (so) == 0;
}
-static CORE_ADDR debug_base; /* Base of dynamic linker structures */
-static CORE_ADDR breakpoint_addr; /* Address where end bkpt is set */
+/* Per pspace SVR4 specific data. */
-/* Local function prototypes */
+struct svr4_info
+{
+ CORE_ADDR debug_base; /* Base of dynamic linker structures. */
+
+ /* Validity flag for debug_loader_offset. */
+ int debug_loader_offset_p;
+
+ /* Load address for the dynamic linker, inferred. */
+ CORE_ADDR debug_loader_offset;
+
+ /* Name of the dynamic linker, valid if debug_loader_offset_p. */
+ char *debug_loader_name;
-static int match_main (char *);
+ /* Load map address for the main executable. */
+ CORE_ADDR main_lm_addr;
-static CORE_ADDR bfd_lookup_symbol (bfd *, char *, flagword);
+ CORE_ADDR interp_text_sect_low;
+ CORE_ADDR interp_text_sect_high;
+ CORE_ADDR interp_plt_sect_low;
+ CORE_ADDR interp_plt_sect_high;
+};
+
+/* Per-program-space data key. */
+static const struct program_space_data *solib_svr4_pspace_data;
+
+static void
+svr4_pspace_data_cleanup (struct program_space *pspace, void *arg)
+{
+ struct svr4_info *info;
+
+ info = program_space_data (pspace, solib_svr4_pspace_data);
+ xfree (info);
+}
+
+/* Get the current svr4 data. If none is found yet, add it now. This
+ function always returns a valid object. */
+
+static struct svr4_info *
+get_svr4_info (void)
+{
+ struct svr4_info *info;
+
+ info = program_space_data (current_program_space, solib_svr4_pspace_data);
+ if (info != NULL)
+ return info;
+
+ info = XZALLOC (struct svr4_info);
+ set_program_space_data (current_program_space, solib_svr4_pspace_data, info);
+ return info;
+}
+
+/* Local function prototypes */
+
+static int match_main (const char *);
/*
SYNOPSIS
- CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname, flagword sect_flags)
+ CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname)
DESCRIPTION
An expensive way to lookup the value of a single symbol for
bfd's that are only temporary anyway. This is used by the
shared library support to find the address of the debugger
- interface structures in the shared library.
+ notification routine in the shared library.
- If SECT_FLAGS is non-zero, only match symbols in sections whose
- flags include all those in SECT_FLAGS.
+ The returned symbol may be in a code or data section; functions
+ will normally be in a code section, but may be in a data section
+ if this architecture uses function descriptors.
Note that 0 is specifically allowed as an error return (no
such symbol).
*/
static CORE_ADDR
-bfd_lookup_symbol (bfd *abfd, char *symname, flagword sect_flags)
+bfd_lookup_symbol (bfd *abfd, const char *symname)
{
long storage_needed;
asymbol *sym;
{
sym = *symbol_table++;
if (strcmp (sym->name, symname) == 0
- && (sym->section->flags & sect_flags) == sect_flags)
+ && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0)
{
- /* Bfd symbols are section relative. */
+ /* BFD symbols are section relative. */
symaddr = sym->value + sym->section->vma;
break;
}
sym = *symbol_table++;
if (strcmp (sym->name, symname) == 0
- && (sym->section->flags & sect_flags) == sect_flags)
+ && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0)
{
- /* Bfd symbols are section relative. */
+ /* BFD symbols are section relative. */
symaddr = sym->value + sym->section->vma;
break;
}
return symaddr;
}
+
+/* Read program header TYPE from inferior memory. The header is found
+ by scanning the OS auxillary vector.
+
+ If TYPE == -1, return the program headers instead of the contents of
+ one program header.
+
+ Return a pointer to allocated memory holding the program header contents,
+ or NULL on failure. If sucessful, and unless P_SECT_SIZE is NULL, the
+ size of those contents is returned to P_SECT_SIZE. Likewise, the target
+ architecture size (32-bit or 64-bit) is returned to P_ARCH_SIZE. */
+
+static gdb_byte *
+read_program_header (int type, int *p_sect_size, int *p_arch_size)
+{
+ enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
+ CORE_ADDR at_phdr, at_phent, at_phnum;
+ int arch_size, sect_size;
+ CORE_ADDR sect_addr;
+ gdb_byte *buf;
+
+ /* Get required auxv elements from target. */
+ if (target_auxv_search (¤t_target, AT_PHDR, &at_phdr) <= 0)
+ return 0;
+ if (target_auxv_search (¤t_target, AT_PHENT, &at_phent) <= 0)
+ return 0;
+ if (target_auxv_search (¤t_target, AT_PHNUM, &at_phnum) <= 0)
+ return 0;
+ if (!at_phdr || !at_phnum)
+ return 0;
+
+ /* Determine ELF architecture type. */
+ if (at_phent == sizeof (Elf32_External_Phdr))
+ arch_size = 32;
+ else if (at_phent == sizeof (Elf64_External_Phdr))
+ arch_size = 64;
+ else
+ return 0;
+
+ /* Find the requested segment. */
+ if (type == -1)
+ {
+ sect_addr = at_phdr;
+ sect_size = at_phent * at_phnum;
+ }
+ else if (arch_size == 32)
+ {
+ Elf32_External_Phdr phdr;
+ int i;
+
+ /* Search for requested PHDR. */
+ for (i = 0; i < at_phnum; i++)
+ {
+ if (target_read_memory (at_phdr + i * sizeof (phdr),
+ (gdb_byte *)&phdr, sizeof (phdr)))
+ return 0;
+
+ if (extract_unsigned_integer ((gdb_byte *)phdr.p_type,
+ 4, byte_order) == type)
+ break;
+ }
+
+ if (i == at_phnum)
+ return 0;
+
+ /* Retrieve address and size. */
+ sect_addr = extract_unsigned_integer ((gdb_byte *)phdr.p_vaddr,
+ 4, byte_order);
+ sect_size = extract_unsigned_integer ((gdb_byte *)phdr.p_memsz,
+ 4, byte_order);
+ }
+ else
+ {
+ Elf64_External_Phdr phdr;
+ int i;
+
+ /* Search for requested PHDR. */
+ for (i = 0; i < at_phnum; i++)
+ {
+ if (target_read_memory (at_phdr + i * sizeof (phdr),
+ (gdb_byte *)&phdr, sizeof (phdr)))
+ return 0;
+
+ if (extract_unsigned_integer ((gdb_byte *)phdr.p_type,
+ 4, byte_order) == type)
+ break;
+ }
+
+ if (i == at_phnum)
+ return 0;
+
+ /* Retrieve address and size. */
+ sect_addr = extract_unsigned_integer ((gdb_byte *)phdr.p_vaddr,
+ 8, byte_order);
+ sect_size = extract_unsigned_integer ((gdb_byte *)phdr.p_memsz,
+ 8, byte_order);
+ }
+
+ /* Read in requested program header. */
+ buf = xmalloc (sect_size);
+ if (target_read_memory (sect_addr, buf, sect_size))
+ {
+ xfree (buf);
+ return NULL;
+ }
+
+ if (p_arch_size)
+ *p_arch_size = arch_size;
+ if (p_sect_size)
+ *p_sect_size = sect_size;
+
+ return buf;
+}
+
+
+/* Return program interpreter string. */
+static gdb_byte *
+find_program_interpreter (void)
+{
+ gdb_byte *buf = NULL;
+
+ /* If we have an exec_bfd, use its section table. */
+ if (exec_bfd
+ && bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
+ {
+ struct bfd_section *interp_sect;
+
+ interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
+ if (interp_sect != NULL)
+ {
+ int sect_size = bfd_section_size (exec_bfd, interp_sect);
+
+ buf = xmalloc (sect_size);
+ bfd_get_section_contents (exec_bfd, interp_sect, buf, 0, sect_size);
+ }
+ }
+
+ /* If we didn't find it, use the target auxillary vector. */
+ if (!buf)
+ buf = read_program_header (PT_INTERP, NULL, NULL);
+
+ return buf;
+}
+
+
+/* Scan for DYNTAG in .dynamic section of ABFD. If DYNTAG is found 1 is
+ returned and the corresponding PTR is set. */
+
+static int
+scan_dyntag (int dyntag, bfd *abfd, CORE_ADDR *ptr)
+{
+ int arch_size, step, sect_size;
+ long dyn_tag;
+ CORE_ADDR dyn_ptr, dyn_addr;
+ gdb_byte *bufend, *bufstart, *buf;
+ Elf32_External_Dyn *x_dynp_32;
+ Elf64_External_Dyn *x_dynp_64;
+ struct bfd_section *sect;
+ struct target_section *target_section;
+
+ if (abfd == NULL)
+ return 0;
+
+ if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
+ return 0;
+
+ arch_size = bfd_get_arch_size (abfd);
+ if (arch_size == -1)
+ return 0;
+
+ /* Find the start address of the .dynamic section. */
+ sect = bfd_get_section_by_name (abfd, ".dynamic");
+ if (sect == NULL)
+ return 0;
+
+ for (target_section = current_target_sections->sections;
+ target_section < current_target_sections->sections_end;
+ target_section++)
+ if (sect == target_section->the_bfd_section)
+ break;
+ if (target_section < current_target_sections->sections_end)
+ dyn_addr = target_section->addr;
+ else
+ {
+ /* ABFD may come from OBJFILE acting only as a symbol file without being
+ loaded into the target (see add_symbol_file_command). This case is
+ such fallback to the file VMA address without the possibility of
+ having the section relocated to its actual in-memory address. */
+
+ dyn_addr = bfd_section_vma (abfd, sect);
+ }
+
+ /* Read in .dynamic from the BFD. We will get the actual value
+ from memory later. */
+ sect_size = bfd_section_size (abfd, sect);
+ buf = bufstart = alloca (sect_size);
+ if (!bfd_get_section_contents (abfd, sect,
+ buf, 0, sect_size))
+ return 0;
+
+ /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
+ step = (arch_size == 32) ? sizeof (Elf32_External_Dyn)
+ : sizeof (Elf64_External_Dyn);
+ for (bufend = buf + sect_size;
+ buf < bufend;
+ buf += step)
+ {
+ if (arch_size == 32)
+ {
+ x_dynp_32 = (Elf32_External_Dyn *) buf;
+ dyn_tag = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_tag);
+ dyn_ptr = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_un.d_ptr);
+ }
+ else
+ {
+ x_dynp_64 = (Elf64_External_Dyn *) buf;
+ dyn_tag = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_tag);
+ dyn_ptr = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_un.d_ptr);
+ }
+ if (dyn_tag == DT_NULL)
+ return 0;
+ if (dyn_tag == dyntag)
+ {
+ /* If requested, try to read the runtime value of this .dynamic
+ entry. */
+ if (ptr)
+ {
+ struct type *ptr_type;
+ gdb_byte ptr_buf[8];
+ CORE_ADDR ptr_addr;
+
+ ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
+ ptr_addr = dyn_addr + (buf - bufstart) + arch_size / 8;
+ if (target_read_memory (ptr_addr, ptr_buf, arch_size / 8) == 0)
+ dyn_ptr = extract_typed_address (ptr_buf, ptr_type);
+ *ptr = dyn_ptr;
+ }
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+/* Scan for DYNTAG in .dynamic section of the target's main executable,
+ found by consulting the OS auxillary vector. If DYNTAG is found 1 is
+ returned and the corresponding PTR is set. */
+
+static int
+scan_dyntag_auxv (int dyntag, CORE_ADDR *ptr)
+{
+ enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
+ int sect_size, arch_size, step;
+ long dyn_tag;
+ CORE_ADDR dyn_ptr;
+ gdb_byte *bufend, *bufstart, *buf;
+
+ /* Read in .dynamic section. */
+ buf = bufstart = read_program_header (PT_DYNAMIC, §_size, &arch_size);
+ if (!buf)
+ return 0;
+
+ /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
+ step = (arch_size == 32) ? sizeof (Elf32_External_Dyn)
+ : sizeof (Elf64_External_Dyn);
+ for (bufend = buf + sect_size;
+ buf < bufend;
+ buf += step)
+ {
+ if (arch_size == 32)
+ {
+ Elf32_External_Dyn *dynp = (Elf32_External_Dyn *) buf;
+
+ dyn_tag = extract_unsigned_integer ((gdb_byte *) dynp->d_tag,
+ 4, byte_order);
+ dyn_ptr = extract_unsigned_integer ((gdb_byte *) dynp->d_un.d_ptr,
+ 4, byte_order);
+ }
+ else
+ {
+ Elf64_External_Dyn *dynp = (Elf64_External_Dyn *) buf;
+
+ dyn_tag = extract_unsigned_integer ((gdb_byte *) dynp->d_tag,
+ 8, byte_order);
+ dyn_ptr = extract_unsigned_integer ((gdb_byte *) dynp->d_un.d_ptr,
+ 8, byte_order);
+ }
+ if (dyn_tag == DT_NULL)
+ break;
+
+ if (dyn_tag == dyntag)
+ {
+ if (ptr)
+ *ptr = dyn_ptr;
+
+ xfree (bufstart);
+ return 1;
+ }
+ }
+
+ xfree (bufstart);
+ return 0;
+}
+
+
/*
LOCAL FUNCTION
static CORE_ADDR
elf_locate_base (void)
{
- struct bfd_section *dyninfo_sect;
- int dyninfo_sect_size;
- CORE_ADDR dyninfo_addr;
- gdb_byte *buf;
- gdb_byte *bufend;
- int arch_size;
-
- /* Find the start address of the .dynamic section. */
- dyninfo_sect = bfd_get_section_by_name (exec_bfd, ".dynamic");
- if (dyninfo_sect == NULL)
- return 0;
- dyninfo_addr = bfd_section_vma (exec_bfd, dyninfo_sect);
-
- /* Read in .dynamic section, silently ignore errors. */
- dyninfo_sect_size = bfd_section_size (exec_bfd, dyninfo_sect);
- buf = alloca (dyninfo_sect_size);
- if (target_read_memory (dyninfo_addr, buf, dyninfo_sect_size))
- return 0;
-
- /* Find the DT_DEBUG entry in the the .dynamic section.
- For mips elf we look for DT_MIPS_RLD_MAP, mips elf apparently has
- no DT_DEBUG entries. */
-
- arch_size = bfd_get_arch_size (exec_bfd);
- if (arch_size == -1) /* failure */
- return 0;
-
- if (arch_size == 32)
- { /* 32-bit elf */
- for (bufend = buf + dyninfo_sect_size;
- buf < bufend;
- buf += sizeof (Elf32_External_Dyn))
- {
- Elf32_External_Dyn *x_dynp = (Elf32_External_Dyn *) buf;
- long dyn_tag;
- CORE_ADDR dyn_ptr;
+ struct minimal_symbol *msymbol;
+ CORE_ADDR dyn_ptr;
- dyn_tag = bfd_h_get_32 (exec_bfd, (bfd_byte *) x_dynp->d_tag);
- if (dyn_tag == DT_NULL)
- break;
- else if (dyn_tag == DT_DEBUG)
- {
- dyn_ptr = bfd_h_get_32 (exec_bfd,
- (bfd_byte *) x_dynp->d_un.d_ptr);
- return dyn_ptr;
- }
- else if (dyn_tag == DT_MIPS_RLD_MAP)
- {
- gdb_byte *pbuf;
- int pbuf_size = TARGET_PTR_BIT / HOST_CHAR_BIT;
-
- pbuf = alloca (pbuf_size);
- /* DT_MIPS_RLD_MAP contains a pointer to the address
- of the dynamic link structure. */
- dyn_ptr = bfd_h_get_32 (exec_bfd,
- (bfd_byte *) x_dynp->d_un.d_ptr);
- if (target_read_memory (dyn_ptr, pbuf, pbuf_size))
- return 0;
- return extract_unsigned_integer (pbuf, pbuf_size);
- }
- }
- }
- else /* 64-bit elf */
+ /* Look for DT_MIPS_RLD_MAP first. MIPS executables use this
+ instead of DT_DEBUG, although they sometimes contain an unused
+ DT_DEBUG. */
+ if (scan_dyntag (DT_MIPS_RLD_MAP, exec_bfd, &dyn_ptr)
+ || scan_dyntag_auxv (DT_MIPS_RLD_MAP, &dyn_ptr))
{
- for (bufend = buf + dyninfo_sect_size;
- buf < bufend;
- buf += sizeof (Elf64_External_Dyn))
- {
- Elf64_External_Dyn *x_dynp = (Elf64_External_Dyn *) buf;
- long dyn_tag;
- CORE_ADDR dyn_ptr;
-
- dyn_tag = bfd_h_get_64 (exec_bfd, (bfd_byte *) x_dynp->d_tag);
- if (dyn_tag == DT_NULL)
- break;
- else if (dyn_tag == DT_DEBUG)
- {
- dyn_ptr = bfd_h_get_64 (exec_bfd,
- (bfd_byte *) x_dynp->d_un.d_ptr);
- return dyn_ptr;
- }
- else if (dyn_tag == DT_MIPS_RLD_MAP)
- {
- gdb_byte *pbuf;
- int pbuf_size = TARGET_PTR_BIT / HOST_CHAR_BIT;
-
- pbuf = alloca (pbuf_size);
- /* DT_MIPS_RLD_MAP contains a pointer to the address
- of the dynamic link structure. */
- dyn_ptr = bfd_h_get_64 (exec_bfd,
- (bfd_byte *) x_dynp->d_un.d_ptr);
- if (target_read_memory (dyn_ptr, pbuf, pbuf_size))
- return 0;
- return extract_unsigned_integer (pbuf, pbuf_size);
- }
- }
+ struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
+ gdb_byte *pbuf;
+ int pbuf_size = TYPE_LENGTH (ptr_type);
+
+ pbuf = alloca (pbuf_size);
+ /* DT_MIPS_RLD_MAP contains a pointer to the address
+ of the dynamic link structure. */
+ if (target_read_memory (dyn_ptr, pbuf, pbuf_size))
+ return 0;
+ return extract_typed_address (pbuf, ptr_type);
}
+ /* Find DT_DEBUG. */
+ if (scan_dyntag (DT_DEBUG, exec_bfd, &dyn_ptr)
+ || scan_dyntag_auxv (DT_DEBUG, &dyn_ptr))
+ return dyn_ptr;
+
+ /* This may be a static executable. Look for the symbol
+ conventionally named _r_debug, as a last resort. */
+ msymbol = lookup_minimal_symbol ("_r_debug", NULL, symfile_objfile);
+ if (msymbol != NULL)
+ return SYMBOL_VALUE_ADDRESS (msymbol);
+
/* DT_DEBUG entry not found. */
return 0;
}
SYNOPSIS
- CORE_ADDR locate_base (void)
+ CORE_ADDR locate_base (struct svr4_info *)
DESCRIPTION
*/
static CORE_ADDR
-locate_base (void)
+locate_base (struct svr4_info *info)
{
/* Check to see if we have a currently valid address, and if so, avoid
doing all this work again and just return the cached address. If
section for ELF executables. There's no point in doing any of this
though if we don't have some link map offsets to work with. */
- if (debug_base == 0 && svr4_have_link_map_offsets ())
- {
- if (exec_bfd != NULL
- && bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
- debug_base = elf_locate_base ();
- }
- return (debug_base);
+ if (info->debug_base == 0 && svr4_have_link_map_offsets ())
+ info->debug_base = elf_locate_base ();
+ return info->debug_base;
}
-/*
+/* Find the first element in the inferior's dynamic link map, and
+ return its address in the inferior. Return zero if the address
+ could not be determined.
- LOCAL FUNCTION
+ FIXME: Perhaps we should validate the info somehow, perhaps by
+ checking r_version for a known version number, or r_state for
+ RT_CONSISTENT. */
- first_link_map_member -- locate first member in dynamic linker's map
+static CORE_ADDR
+solib_svr4_r_map (struct svr4_info *info)
+{
+ struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
+ struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
+ CORE_ADDR addr = 0;
+ volatile struct gdb_exception ex;
- SYNOPSIS
+ TRY_CATCH (ex, RETURN_MASK_ERROR)
+ {
+ addr = read_memory_typed_address (info->debug_base + lmo->r_map_offset,
+ ptr_type);
+ }
+ exception_print (gdb_stderr, ex);
+ return addr;
+}
- static CORE_ADDR first_link_map_member (void)
+/* Find r_brk from the inferior's debug base. */
- DESCRIPTION
+static CORE_ADDR
+solib_svr4_r_brk (struct svr4_info *info)
+{
+ struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
+ struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
- Find the first element in the inferior's dynamic link map, and
- return its address in the inferior. This function doesn't copy the
- link map entry itself into our address space; current_sos actually
- does the reading. */
+ return read_memory_typed_address (info->debug_base + lmo->r_brk_offset,
+ ptr_type);
+}
+
+/* Find the link map for the dynamic linker (if it is not in the
+ normal list of loaded shared objects). */
static CORE_ADDR
-first_link_map_member (void)
+solib_svr4_r_ldsomap (struct svr4_info *info)
{
- CORE_ADDR lm = 0;
struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
- gdb_byte *r_map_buf = xmalloc (lmo->r_map_size);
- struct cleanup *cleanups = make_cleanup (xfree, r_map_buf);
+ struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
+ enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
+ ULONGEST version;
+
+ /* Check version, and return zero if `struct r_debug' doesn't have
+ the r_ldsomap member. */
+ version
+ = read_memory_unsigned_integer (info->debug_base + lmo->r_version_offset,
+ lmo->r_version_size, byte_order);
+ if (version < 2 || lmo->r_ldsomap_offset == -1)
+ return 0;
- read_memory (debug_base + lmo->r_map_offset, r_map_buf, lmo->r_map_size);
+ return read_memory_typed_address (info->debug_base + lmo->r_ldsomap_offset,
+ ptr_type);
+}
- /* Assume that the address is unsigned. */
- lm = extract_unsigned_integer (r_map_buf, lmo->r_map_size);
+/* On Solaris systems with some versions of the dynamic linker,
+ ld.so's l_name pointer points to the SONAME in the string table
+ rather than into writable memory. So that GDB can find shared
+ libraries when loading a core file generated by gcore, ensure that
+ memory areas containing the l_name string are saved in the core
+ file. */
- /* FIXME: Perhaps we should validate the info somehow, perhaps by
- checking r_version for a known version number, or r_state for
- RT_CONSISTENT. */
+static int
+svr4_keep_data_in_core (CORE_ADDR vaddr, unsigned long size)
+{
+ struct svr4_info *info;
+ CORE_ADDR ldsomap;
+ struct so_list *new;
+ struct cleanup *old_chain;
+ struct link_map_offsets *lmo;
+ CORE_ADDR lm_name;
+
+ info = get_svr4_info ();
+
+ info->debug_base = 0;
+ locate_base (info);
+ if (!info->debug_base)
+ return 0;
- do_cleanups (cleanups);
+ ldsomap = solib_svr4_r_ldsomap (info);
+ if (!ldsomap)
+ return 0;
- return (lm);
+ lmo = svr4_fetch_link_map_offsets ();
+ new = XZALLOC (struct so_list);
+ old_chain = make_cleanup (xfree, new);
+ new->lm_info = xmalloc (sizeof (struct lm_info));
+ make_cleanup (xfree, new->lm_info);
+ new->lm_info->l_addr = (CORE_ADDR)-1;
+ new->lm_info->lm_addr = ldsomap;
+ new->lm_info->lm = xzalloc (lmo->link_map_size);
+ make_cleanup (xfree, new->lm_info->lm);
+ read_memory (ldsomap, new->lm_info->lm, lmo->link_map_size);
+ lm_name = LM_NAME (new);
+ do_cleanups (old_chain);
+
+ return (lm_name >= vaddr && lm_name < vaddr + size);
}
/*
If FROM_TTYP dereferences to a non-zero integer, allow messages to
be printed. This parameter is a pointer rather than an int because
open_symbol_file_object() is called via catch_errors() and
- catch_errors() requires a pointer argument. */
+ catch_errors() requires a pointer argument. */
static int
open_symbol_file_object (void *from_ttyp)
int errcode;
int from_tty = *(int *)from_ttyp;
struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
- gdb_byte *l_name_buf = xmalloc (lmo->l_name_size);
+ struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
+ int l_name_size = TYPE_LENGTH (ptr_type);
+ gdb_byte *l_name_buf = xmalloc (l_name_size);
struct cleanup *cleanups = make_cleanup (xfree, l_name_buf);
+ struct svr4_info *info = get_svr4_info ();
if (symfile_objfile)
- if (!query ("Attempt to reload symbols from process? "))
+ if (!query (_("Attempt to reload symbols from process? ")))
return 0;
- if ((debug_base = locate_base ()) == 0)
- return 0; /* failed somehow... */
+ /* Always locate the debug struct, in case it has moved. */
+ info->debug_base = 0;
+ if (locate_base (info) == 0)
+ return 0; /* failed somehow... */
/* First link map member should be the executable. */
- if ((lm = first_link_map_member ()) == 0)
- return 0; /* failed somehow... */
+ lm = solib_svr4_r_map (info);
+ if (lm == 0)
+ return 0; /* failed somehow... */
/* Read address of name from target memory to GDB. */
- read_memory (lm + lmo->l_name_offset, l_name_buf, lmo->l_name_size);
+ read_memory (lm + lmo->l_name_offset, l_name_buf, l_name_size);
- /* Convert the address to host format. Assume that the address is
- unsigned. */
- l_name = extract_unsigned_integer (l_name_buf, lmo->l_name_size);
+ /* Convert the address to host format. */
+ l_name = extract_typed_address (l_name_buf, ptr_type);
/* Free l_name_buf. */
do_cleanups (cleanups);
/* Now fetch the filename from target memory. */
target_read_string (l_name, &filename, SO_NAME_MAX_PATH_SIZE - 1, &errcode);
+ make_cleanup (xfree, filename);
if (errcode)
{
return 0;
}
- make_cleanup (xfree, filename);
/* Have a pathname: read the symbol file. */
symbol_file_add_main (filename, from_tty);
return 1;
}
+/* If no shared library information is available from the dynamic
+ linker, build a fallback list from other sources. */
+
+static struct so_list *
+svr4_default_sos (void)
+{
+ struct svr4_info *info = get_svr4_info ();
+
+ struct so_list *head = NULL;
+ struct so_list **link_ptr = &head;
+
+ if (info->debug_loader_offset_p)
+ {
+ struct so_list *new = XZALLOC (struct so_list);
+
+ new->lm_info = xmalloc (sizeof (struct lm_info));
+
+ /* Nothing will ever check the cached copy of the link
+ map if we set l_addr. */
+ new->lm_info->l_addr = info->debug_loader_offset;
+ new->lm_info->lm_addr = 0;
+ new->lm_info->lm = NULL;
+
+ strncpy (new->so_name, info->debug_loader_name,
+ SO_NAME_MAX_PATH_SIZE - 1);
+ new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
+ strcpy (new->so_original_name, new->so_name);
+
+ *link_ptr = new;
+ link_ptr = &new->next;
+ }
+
+ return head;
+}
+
/* LOCAL FUNCTION
current_sos -- build a list of currently loaded shared objects
static struct so_list *
svr4_current_sos (void)
{
- CORE_ADDR lm;
+ CORE_ADDR lm, prev_lm;
struct so_list *head = 0;
struct so_list **link_ptr = &head;
+ CORE_ADDR ldsomap = 0;
+ struct svr4_info *info;
- /* Make sure we've looked up the inferior's dynamic linker's base
- structure. */
- if (! debug_base)
- {
- debug_base = locate_base ();
+ info = get_svr4_info ();
- /* If we can't find the dynamic linker's base structure, this
- must not be a dynamically linked executable. Hmm. */
- if (! debug_base)
- return 0;
- }
+ /* Always locate the debug struct, in case it has moved. */
+ info->debug_base = 0;
+ locate_base (info);
+
+ /* If we can't find the dynamic linker's base structure, this
+ must not be a dynamically linked executable. Hmm. */
+ if (! info->debug_base)
+ return svr4_default_sos ();
/* Walk the inferior's link map list, and build our list of
`struct so_list' nodes. */
- lm = first_link_map_member ();
+ prev_lm = 0;
+ lm = solib_svr4_r_map (info);
+
while (lm)
{
struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
- struct so_list *new
- = (struct so_list *) xmalloc (sizeof (struct so_list));
+ struct so_list *new = XZALLOC (struct so_list);
struct cleanup *old_chain = make_cleanup (xfree, new);
-
- memset (new, 0, sizeof (*new));
+ CORE_ADDR next_lm;
new->lm_info = xmalloc (sizeof (struct lm_info));
make_cleanup (xfree, new->lm_info);
- new->lm_info->lm = xmalloc (lmo->link_map_size);
+ new->lm_info->l_addr = (CORE_ADDR)-1;
+ new->lm_info->lm_addr = lm;
+ new->lm_info->lm = xzalloc (lmo->link_map_size);
make_cleanup (xfree, new->lm_info->lm);
- memset (new->lm_info->lm, 0, lmo->link_map_size);
read_memory (lm, new->lm_info->lm, lmo->link_map_size);
- lm = LM_NEXT (new);
+ next_lm = LM_NEXT (new);
+
+ if (LM_PREV (new) != prev_lm)
+ {
+ warning (_("Corrupted shared library list"));
+ free_so (new);
+ next_lm = 0;
+ }
/* For SVR4 versions, the first entry in the link map is for the
inferior executable, so we must ignore it. For some versions of
SVR4, it has no name. For others (Solaris 2.3 for example), it
does have a name, so we can no longer use a missing name to
- decide when to ignore it. */
- if (IGNORE_FIRST_LINK_MAP_ENTRY (new))
- free_so (new);
+ decide when to ignore it. */
+ else if (IGNORE_FIRST_LINK_MAP_ENTRY (new) && ldsomap == 0)
+ {
+ info->main_lm_addr = new->lm_info->lm_addr;
+ free_so (new);
+ }
else
{
int errcode;
{
strncpy (new->so_name, buffer, SO_NAME_MAX_PATH_SIZE - 1);
new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
- xfree (buffer);
strcpy (new->so_original_name, new->so_name);
}
+ xfree (buffer);
/* If this entry has no name, or its name matches the name
for the main executable, don't include it in the list. */
}
}
+ prev_lm = lm;
+ lm = next_lm;
+
+ /* On Solaris, the dynamic linker is not in the normal list of
+ shared objects, so make sure we pick it up too. Having
+ symbol information for the dynamic linker is quite crucial
+ for skipping dynamic linker resolver code. */
+ if (lm == 0 && ldsomap == 0)
+ {
+ lm = ldsomap = solib_svr4_r_ldsomap (info);
+ prev_lm = 0;
+ }
+
discard_cleanups (old_chain);
}
+ if (head == NULL)
+ return svr4_default_sos ();
+
return head;
}
-/* Get the address of the link_map for a given OBJFILE. Loop through
- the link maps, and return the address of the one corresponding to
- the given objfile. Note that this function takes into account that
- objfile can be the main executable, not just a shared library. The
- main executable has always an empty name field in the linkmap. */
+/* Get the address of the link_map for a given OBJFILE. */
CORE_ADDR
svr4_fetch_objfile_link_map (struct objfile *objfile)
{
- CORE_ADDR lm;
+ struct so_list *so;
+ struct svr4_info *info = get_svr4_info ();
- if ((debug_base = locate_base ()) == 0)
- return 0; /* failed somehow... */
+ /* Cause svr4_current_sos() to be run if it hasn't been already. */
+ if (info->main_lm_addr == 0)
+ solib_add (NULL, 0, ¤t_target, auto_solib_add);
- /* Position ourselves on the first link map. */
- lm = first_link_map_member ();
- while (lm)
- {
- /* Get info on the layout of the r_debug and link_map structures. */
- struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
- int errcode;
- char *buffer;
- struct lm_info objfile_lm_info;
- struct cleanup *old_chain;
- CORE_ADDR name_address;
- gdb_byte *l_name_buf = xmalloc (lmo->l_name_size);
- old_chain = make_cleanup (xfree, l_name_buf);
-
- /* Set up the buffer to contain the portion of the link_map
- structure that gdb cares about. Note that this is not the
- whole link_map structure. */
- objfile_lm_info.lm = xmalloc (lmo->link_map_size);
- make_cleanup (xfree, objfile_lm_info.lm);
- memset (objfile_lm_info.lm, 0, lmo->link_map_size);
-
- /* Read the link map into our internal structure. */
- read_memory (lm, objfile_lm_info.lm, lmo->link_map_size);
-
- /* Read address of name from target memory to GDB. */
- read_memory (lm + lmo->l_name_offset, l_name_buf, lmo->l_name_size);
-
- /* Extract this object's name. Assume that the address is
- unsigned. */
- name_address = extract_unsigned_integer (l_name_buf, lmo->l_name_size);
- target_read_string (name_address, &buffer,
- SO_NAME_MAX_PATH_SIZE - 1, &errcode);
- make_cleanup (xfree, buffer);
- if (errcode != 0)
- warning (_("Can't read pathname for load map: %s."),
- safe_strerror (errcode));
- else
- {
- /* Is this the linkmap for the file we want? */
- /* If the file is not a shared library and has no name,
- we are sure it is the main executable, so we return that. */
- if ((buffer && strcmp (buffer, objfile->name) == 0)
- || (!(objfile->flags & OBJF_SHARED) && (strcmp (buffer, "") == 0)))
- {
- do_cleanups (old_chain);
- return lm;
- }
- }
- /* Not the file we wanted, continue checking. Assume that the
- address is unsigned. */
- lm = extract_unsigned_integer (objfile_lm_info.lm + lmo->l_next_offset,
- lmo->l_next_size);
- do_cleanups (old_chain);
- }
+ /* svr4_current_sos() will set main_lm_addr for the main executable. */
+ if (objfile == symfile_objfile)
+ return info->main_lm_addr;
+
+ /* The other link map addresses may be found by examining the list
+ of shared libraries. */
+ for (so = master_so_list (); so; so = so->next)
+ if (so->objfile == objfile)
+ return so->lm_info->lm_addr;
+
+ /* Not found! */
return 0;
}
non-zero iff SONAME matches one of the known main executable names. */
static int
-match_main (char *soname)
+match_main (const char *soname)
{
- char **mainp;
+ const char * const *mainp;
for (mainp = main_name_list; *mainp != NULL; mainp++)
{
/* Return 1 if PC lies in the dynamic symbol resolution code of the
SVR4 run time loader. */
-static CORE_ADDR interp_text_sect_low;
-static CORE_ADDR interp_text_sect_high;
-static CORE_ADDR interp_plt_sect_low;
-static CORE_ADDR interp_plt_sect_high;
-static int
+int
svr4_in_dynsym_resolve_code (CORE_ADDR pc)
{
- return ((pc >= interp_text_sect_low && pc < interp_text_sect_high)
- || (pc >= interp_plt_sect_low && pc < interp_plt_sect_high)
+ struct svr4_info *info = get_svr4_info ();
+
+ return ((pc >= info->interp_text_sect_low
+ && pc < info->interp_text_sect_high)
+ || (pc >= info->interp_plt_sect_low
+ && pc < info->interp_plt_sect_high)
|| in_plt_section (pc, NULL));
}
gdbarch_convert_from_func_ptr_addr(). The method
gdbarch_convert_from_func_ptr_addr() is the merely the identify
function for targets which don't use function descriptors. */
- return gdbarch_convert_from_func_ptr_addr (current_gdbarch,
+ return gdbarch_convert_from_func_ptr_addr (target_gdbarch,
bfd_get_start_address (abfd),
targ);
}
*/
static int
-enable_break (void)
+enable_break (struct svr4_info *info, int from_tty)
{
- int success = 0;
-
-#ifdef BKPT_AT_SYMBOL
-
struct minimal_symbol *msymbol;
- char **bkpt_namep;
+ const char * const *bkpt_namep;
asection *interp_sect;
+ gdb_byte *interp_name;
+ CORE_ADDR sym_addr;
+
+ info->interp_text_sect_low = info->interp_text_sect_high = 0;
+ info->interp_plt_sect_low = info->interp_plt_sect_high = 0;
- /* First, remove all the solib event breakpoints. Their addresses
- may have changed since the last time we ran the program. */
- remove_solib_event_breakpoints ();
+ /* If we already have a shared library list in the target, and
+ r_debug contains r_brk, set the breakpoint there - this should
+ mean r_brk has already been relocated. Assume the dynamic linker
+ is the object containing r_brk. */
- interp_text_sect_low = interp_text_sect_high = 0;
- interp_plt_sect_low = interp_plt_sect_high = 0;
+ solib_add (NULL, from_tty, ¤t_target, auto_solib_add);
+ sym_addr = 0;
+ if (info->debug_base && solib_svr4_r_map (info) != 0)
+ sym_addr = solib_svr4_r_brk (info);
- /* Find the .interp section; if not found, warn the user and drop
+ if (sym_addr != 0)
+ {
+ struct obj_section *os;
+
+ sym_addr = gdbarch_addr_bits_remove
+ (target_gdbarch, gdbarch_convert_from_func_ptr_addr (target_gdbarch,
+ sym_addr,
+ ¤t_target));
+
+ /* On at least some versions of Solaris there's a dynamic relocation
+ on _r_debug.r_brk and SYM_ADDR may not be relocated yet, e.g., if
+ we get control before the dynamic linker has self-relocated.
+ Check if SYM_ADDR is in a known section, if it is assume we can
+ trust its value. This is just a heuristic though, it could go away
+ or be replaced if it's getting in the way.
+
+ On ARM we need to know whether the ISA of rtld_db_dlactivity (or
+ however it's spelled in your particular system) is ARM or Thumb.
+ That knowledge is encoded in the address, if it's Thumb the low bit
+ is 1. However, we've stripped that info above and it's not clear
+ what all the consequences are of passing a non-addr_bits_remove'd
+ address to create_solib_event_breakpoint. The call to
+ find_pc_section verifies we know about the address and have some
+ hope of computing the right kind of breakpoint to use (via
+ symbol info). It does mean that GDB needs to be pointed at a
+ non-stripped version of the dynamic linker in order to obtain
+ information it already knows about. Sigh. */
+
+ os = find_pc_section (sym_addr);
+ if (os != NULL)
+ {
+ /* Record the relocated start and end address of the dynamic linker
+ text and plt section for svr4_in_dynsym_resolve_code. */
+ bfd *tmp_bfd;
+ CORE_ADDR load_addr;
+
+ tmp_bfd = os->objfile->obfd;
+ load_addr = ANOFFSET (os->objfile->section_offsets,
+ os->objfile->sect_index_text);
+
+ interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
+ if (interp_sect)
+ {
+ info->interp_text_sect_low =
+ bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
+ info->interp_text_sect_high =
+ info->interp_text_sect_low
+ + bfd_section_size (tmp_bfd, interp_sect);
+ }
+ interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt");
+ if (interp_sect)
+ {
+ info->interp_plt_sect_low =
+ bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
+ info->interp_plt_sect_high =
+ info->interp_plt_sect_low
+ + bfd_section_size (tmp_bfd, interp_sect);
+ }
+
+ create_solib_event_breakpoint (target_gdbarch, sym_addr);
+ return 1;
+ }
+ }
+
+ /* Find the program interpreter; if not found, warn the user and drop
into the old breakpoint at symbol code. */
- interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
- if (interp_sect)
+ interp_name = find_program_interpreter ();
+ if (interp_name)
{
- unsigned int interp_sect_size;
- char *buf;
CORE_ADDR load_addr = 0;
int load_addr_found = 0;
+ int loader_found_in_list = 0;
struct so_list *so;
bfd *tmp_bfd = NULL;
struct target_ops *tmp_bfd_target;
- int tmp_fd = -1;
- char *tmp_pathname = NULL;
- CORE_ADDR sym_addr = 0;
+ volatile struct gdb_exception ex;
- /* Read the contents of the .interp section into a local buffer;
- the contents specify the dynamic linker this program uses. */
- interp_sect_size = bfd_section_size (exec_bfd, interp_sect);
- buf = alloca (interp_sect_size);
- bfd_get_section_contents (exec_bfd, interp_sect,
- buf, 0, interp_sect_size);
+ sym_addr = 0;
/* Now we need to figure out where the dynamic linker was
loaded so that we can load its symbols and place a breakpoint
be trivial on GNU/Linux). Therefore, we have to try an alternate
mechanism to find the dynamic linker's base address. */
- tmp_fd = solib_open (buf, &tmp_pathname);
- if (tmp_fd >= 0)
- tmp_bfd = bfd_fdopenr (tmp_pathname, gnutarget, tmp_fd);
-
+ TRY_CATCH (ex, RETURN_MASK_ALL)
+ {
+ tmp_bfd = solib_bfd_open (interp_name);
+ }
if (tmp_bfd == NULL)
goto bkpt_at_symbol;
- /* Make sure the dynamic linker's really a useful object. */
- if (!bfd_check_format (tmp_bfd, bfd_object))
- {
- warning (_("Unable to grok dynamic linker %s as an object file"), buf);
- bfd_close (tmp_bfd);
- goto bkpt_at_symbol;
- }
-
/* Now convert the TMP_BFD into a target. That way target, as
well as BFD operations can be used. Note that closing the
target will also close the underlying bfd. */
/* On a running target, we can get the dynamic linker's base
address from the shared library table. */
- solib_add (NULL, 0, NULL, auto_solib_add);
so = master_so_list ();
while (so)
{
- if (strcmp (buf, so->so_original_name) == 0)
+ if (svr4_same_1 (interp_name, so->so_original_name))
{
load_addr_found = 1;
- load_addr = LM_ADDR (so);
+ loader_found_in_list = 1;
+ load_addr = LM_ADDR_CHECK (so, tmp_bfd);
break;
}
so = so->next;
}
+ /* If we were not able to find the base address of the loader
+ from our so_list, then try using the AT_BASE auxilliary entry. */
+ if (!load_addr_found)
+ if (target_auxv_search (¤t_target, AT_BASE, &load_addr) > 0)
+ {
+ int addr_bit = gdbarch_addr_bit (target_gdbarch);
+
+ /* Ensure LOAD_ADDR has proper sign in its possible upper bits so
+ that `+ load_addr' will overflow CORE_ADDR width not creating
+ invalid addresses like 0x101234567 for 32bit inferiors on 64bit
+ GDB. */
+
+ if (addr_bit < (sizeof (CORE_ADDR) * HOST_CHAR_BIT))
+ {
+ CORE_ADDR space_size = (CORE_ADDR) 1 << addr_bit;
+ CORE_ADDR tmp_entry_point = exec_entry_point (tmp_bfd,
+ tmp_bfd_target);
+
+ gdb_assert (load_addr < space_size);
+
+ /* TMP_ENTRY_POINT exceeding SPACE_SIZE would be for prelinked
+ 64bit ld.so with 32bit executable, it should not happen. */
+
+ if (tmp_entry_point < space_size
+ && tmp_entry_point + load_addr >= space_size)
+ load_addr -= space_size;
+ }
+
+ load_addr_found = 1;
+ }
+
/* Otherwise we find the dynamic linker's base address by examining
the current pc (which should point at the entry point for the
- dynamic linker) and subtracting the offset of the entry point. */
+ dynamic linker) and subtracting the offset of the entry point.
+
+ This is more fragile than the previous approaches, but is a good
+ fallback method because it has actually been working well in
+ most cases. */
if (!load_addr_found)
- load_addr = (read_pc ()
- - exec_entry_point (tmp_bfd, tmp_bfd_target));
+ {
+ struct regcache *regcache
+ = get_thread_arch_regcache (inferior_ptid, target_gdbarch);
+
+ load_addr = (regcache_read_pc (regcache)
+ - exec_entry_point (tmp_bfd, tmp_bfd_target));
+ }
+
+ if (!loader_found_in_list)
+ {
+ info->debug_loader_name = xstrdup (interp_name);
+ info->debug_loader_offset_p = 1;
+ info->debug_loader_offset = load_addr;
+ solib_add (NULL, from_tty, ¤t_target, auto_solib_add);
+ }
/* Record the relocated start and end address of the dynamic linker
text and plt section for svr4_in_dynsym_resolve_code. */
interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
if (interp_sect)
{
- interp_text_sect_low =
+ info->interp_text_sect_low =
bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
- interp_text_sect_high =
- interp_text_sect_low + bfd_section_size (tmp_bfd, interp_sect);
+ info->interp_text_sect_high =
+ info->interp_text_sect_low
+ + bfd_section_size (tmp_bfd, interp_sect);
}
interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt");
if (interp_sect)
{
- interp_plt_sect_low =
+ info->interp_plt_sect_low =
bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
- interp_plt_sect_high =
- interp_plt_sect_low + bfd_section_size (tmp_bfd, interp_sect);
+ info->interp_plt_sect_high =
+ info->interp_plt_sect_low
+ + bfd_section_size (tmp_bfd, interp_sect);
}
/* Now try to set a breakpoint in the dynamic linker. */
for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
{
- /* On ABI's that use function descriptors, there are usually
- two linker symbols associated with each C function: one
- pointing at the actual entry point of the machine code,
- and one pointing at the function's descriptor. The
- latter symbol has the same name as the C function.
-
- What we're looking for here is the machine code entry
- point, so we are only interested in symbols in code
- sections. */
- sym_addr = bfd_lookup_symbol (tmp_bfd, *bkpt_namep, SEC_CODE);
+ sym_addr = bfd_lookup_symbol (tmp_bfd, *bkpt_namep);
if (sym_addr != 0)
break;
}
+ if (sym_addr != 0)
+ /* Convert 'sym_addr' from a function pointer to an address.
+ Because we pass tmp_bfd_target instead of the current
+ target, this will always produce an unrelocated value. */
+ sym_addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch,
+ sym_addr,
+ tmp_bfd_target);
+
/* We're done with both the temporary bfd and target. Remember,
closing the target closes the underlying bfd. */
target_close (tmp_bfd_target, 0);
if (sym_addr != 0)
{
- create_solib_event_breakpoint (load_addr + sym_addr);
+ create_solib_event_breakpoint (target_gdbarch, load_addr + sym_addr);
+ xfree (interp_name);
return 1;
}
/* For whatever reason we couldn't set a breakpoint in the dynamic
linker. Warn and drop into the old code. */
bkpt_at_symbol:
- warning (_("Unable to find dynamic linker breakpoint function.\nGDB will be unable to debug shared library initializers\nand track explicitly loaded dynamic code."));
+ xfree (interp_name);
+ warning (_("Unable to find dynamic linker breakpoint function.\n"
+ "GDB will be unable to debug shared library initializers\n"
+ "and track explicitly loaded dynamic code."));
}
- /* Scan through the list of symbols, trying to look up the symbol and
- set a breakpoint there. Terminate loop when we/if we succeed. */
+ /* Scan through the lists of symbols, trying to look up the symbol and
+ set a breakpoint there. Terminate loop when we/if we succeed. */
- breakpoint_addr = 0;
- for (bkpt_namep = bkpt_names; *bkpt_namep != NULL; bkpt_namep++)
+ for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
{
msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile);
if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
{
- create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol));
+ sym_addr = SYMBOL_VALUE_ADDRESS (msymbol);
+ sym_addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch,
+ sym_addr,
+ ¤t_target);
+ create_solib_event_breakpoint (target_gdbarch, sym_addr);
return 1;
}
}
- /* Nothing good happened. */
- success = 0;
-
-#endif /* BKPT_AT_SYMBOL */
-
- return (success);
+ if (!current_inferior ()->attach_flag)
+ {
+ for (bkpt_namep = bkpt_names; *bkpt_namep != NULL; bkpt_namep++)
+ {
+ msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile);
+ if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
+ {
+ sym_addr = SYMBOL_VALUE_ADDRESS (msymbol);
+ sym_addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch,
+ sym_addr,
+ ¤t_target);
+ create_solib_event_breakpoint (target_gdbarch, sym_addr);
+ return 1;
+ }
+ }
+ }
+ return 0;
}
/*
{
}
-/* Relocate the main executable. This function should be called upon
- stopping the inferior process at the entry point to the program.
- The entry point from BFD is compared to the PC and if they are
- different, the main executable is relocated by the proper amount.
+/* Read the ELF program headers from ABFD. Return the contents and
+ set *PHDRS_SIZE to the size of the program headers. */
+
+static gdb_byte *
+read_program_headers_from_bfd (bfd *abfd, int *phdrs_size)
+{
+ Elf_Internal_Ehdr *ehdr;
+ gdb_byte *buf;
+
+ ehdr = elf_elfheader (abfd);
+
+ *phdrs_size = ehdr->e_phnum * ehdr->e_phentsize;
+ if (*phdrs_size == 0)
+ return NULL;
+
+ buf = xmalloc (*phdrs_size);
+ if (bfd_seek (abfd, ehdr->e_phoff, SEEK_SET) != 0
+ || bfd_bread (buf, *phdrs_size, abfd) != *phdrs_size)
+ {
+ xfree (buf);
+ return NULL;
+ }
+
+ return buf;
+}
+
+/* Return 1 and fill *DISPLACEMENTP with detected PIE offset of inferior
+ exec_bfd. Otherwise return 0.
+
+ We relocate all of the sections by the same amount. This
+ behavior is mandated by recent editions of the System V ABI.
+ According to the System V Application Binary Interface,
+ Edition 4.1, page 5-5:
+
+ ... Though the system chooses virtual addresses for
+ individual processes, it maintains the segments' relative
+ positions. Because position-independent code uses relative
+ addressesing between segments, the difference between
+ virtual addresses in memory must match the difference
+ between virtual addresses in the file. The difference
+ between the virtual address of any segment in memory and
+ the corresponding virtual address in the file is thus a
+ single constant value for any one executable or shared
+ object in a given process. This difference is the base
+ address. One use of the base address is to relocate the
+ memory image of the program during dynamic linking.
+
+ The same language also appears in Edition 4.0 of the System V
+ ABI and is left unspecified in some of the earlier editions.
+
+ Decide if the objfile needs to be relocated. As indicated above, we will
+ only be here when execution is stopped. But during attachment PC can be at
+ arbitrary address therefore regcache_read_pc can be misleading (contrary to
+ the auxv AT_ENTRY value). Moreover for executable with interpreter section
+ regcache_read_pc would point to the interpreter and not the main executable.
+
+ So, to summarize, relocations are necessary when the start address obtained
+ from the executable is different from the address in auxv AT_ENTRY entry.
- As written it will only attempt to relocate executables which
- lack interpreter sections. It seems likely that only dynamic
- linker executables will get relocated, though it should work
- properly for a position-independent static executable as well. */
+ [ The astute reader will note that we also test to make sure that
+ the executable in question has the DYNAMIC flag set. It is my
+ opinion that this test is unnecessary (undesirable even). It
+ was added to avoid inadvertent relocation of an executable
+ whose e_type member in the ELF header is not ET_DYN. There may
+ be a time in the future when it is desirable to do relocations
+ on other types of files as well in which case this condition
+ should either be removed or modified to accomodate the new file
+ type. - Kevin, Nov 2000. ] */
+
+static int
+svr4_exec_displacement (CORE_ADDR *displacementp)
+{
+ /* ENTRY_POINT is a possible function descriptor - before
+ a call to gdbarch_convert_from_func_ptr_addr. */
+ CORE_ADDR entry_point, displacement;
+
+ if (exec_bfd == NULL)
+ return 0;
+
+ /* Therefore for ELF it is ET_EXEC and not ET_DYN. Both shared libraries
+ being executed themselves and PIE (Position Independent Executable)
+ executables are ET_DYN. */
+
+ if ((bfd_get_file_flags (exec_bfd) & DYNAMIC) == 0)
+ return 0;
+
+ if (target_auxv_search (¤t_target, AT_ENTRY, &entry_point) <= 0)
+ return 0;
+
+ displacement = entry_point - bfd_get_start_address (exec_bfd);
+
+ /* Verify the DISPLACEMENT candidate complies with the required page
+ alignment. It is cheaper than the program headers comparison below. */
+
+ if (bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
+ {
+ const struct elf_backend_data *elf = get_elf_backend_data (exec_bfd);
+
+ /* p_align of PT_LOAD segments does not specify any alignment but
+ only congruency of addresses:
+ p_offset % p_align == p_vaddr % p_align
+ Kernel is free to load the executable with lower alignment. */
+
+ if ((displacement & (elf->minpagesize - 1)) != 0)
+ return 0;
+ }
+
+ /* Verify that the auxilliary vector describes the same file as exec_bfd, by
+ comparing their program headers. If the program headers in the auxilliary
+ vector do not match the program headers in the executable, then we are
+ looking at a different file than the one used by the kernel - for
+ instance, "gdb program" connected to "gdbserver :PORT ld.so program". */
+
+ if (bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
+ {
+ /* Be optimistic and clear OK only if GDB was able to verify the headers
+ really do not match. */
+ int phdrs_size, phdrs2_size, ok = 1;
+ gdb_byte *buf, *buf2;
+ int arch_size;
+
+ buf = read_program_header (-1, &phdrs_size, &arch_size);
+ buf2 = read_program_headers_from_bfd (exec_bfd, &phdrs2_size);
+ if (buf != NULL && buf2 != NULL)
+ {
+ enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
+
+ /* We are dealing with three different addresses. EXEC_BFD
+ represents current address in on-disk file. target memory content
+ may be different from EXEC_BFD as the file may have been prelinked
+ to a different address after the executable has been loaded.
+ Moreover the address of placement in target memory can be
+ different from what the program headers in target memory say -
+ this is the goal of PIE.
+
+ Detected DISPLACEMENT covers both the offsets of PIE placement and
+ possible new prelink performed after start of the program. Here
+ relocate BUF and BUF2 just by the EXEC_BFD vs. target memory
+ content offset for the verification purpose. */
+
+ if (phdrs_size != phdrs2_size
+ || bfd_get_arch_size (exec_bfd) != arch_size)
+ ok = 0;
+ else if (arch_size == 32
+ && phdrs_size >= sizeof (Elf32_External_Phdr)
+ && phdrs_size % sizeof (Elf32_External_Phdr) == 0)
+ {
+ Elf_Internal_Ehdr *ehdr2 = elf_tdata (exec_bfd)->elf_header;
+ Elf_Internal_Phdr *phdr2 = elf_tdata (exec_bfd)->phdr;
+ CORE_ADDR displacement = 0;
+ int i;
+
+ /* DISPLACEMENT could be found more easily by the difference of
+ ehdr2->e_entry. But we haven't read the ehdr yet, and we
+ already have enough information to compute that displacement
+ with what we've read. */
+
+ for (i = 0; i < ehdr2->e_phnum; i++)
+ if (phdr2[i].p_type == PT_LOAD)
+ {
+ Elf32_External_Phdr *phdrp;
+ gdb_byte *buf_vaddr_p, *buf_paddr_p;
+ CORE_ADDR vaddr, paddr;
+ CORE_ADDR displacement_vaddr = 0;
+ CORE_ADDR displacement_paddr = 0;
+
+ phdrp = &((Elf32_External_Phdr *) buf)[i];
+ buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
+ buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
+
+ vaddr = extract_unsigned_integer (buf_vaddr_p, 4,
+ byte_order);
+ displacement_vaddr = vaddr - phdr2[i].p_vaddr;
+
+ paddr = extract_unsigned_integer (buf_paddr_p, 4,
+ byte_order);
+ displacement_paddr = paddr - phdr2[i].p_paddr;
+
+ if (displacement_vaddr == displacement_paddr)
+ displacement = displacement_vaddr;
+
+ break;
+ }
+
+ /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
+
+ for (i = 0; i < phdrs_size / sizeof (Elf32_External_Phdr); i++)
+ {
+ Elf32_External_Phdr *phdrp;
+ Elf32_External_Phdr *phdr2p;
+ gdb_byte *buf_vaddr_p, *buf_paddr_p;
+ CORE_ADDR vaddr, paddr;
+ asection *plt2_asect;
+
+ phdrp = &((Elf32_External_Phdr *) buf)[i];
+ buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
+ buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
+ phdr2p = &((Elf32_External_Phdr *) buf2)[i];
+
+ /* PT_GNU_STACK is an exception by being never relocated by
+ prelink as its addresses are always zero. */
+
+ if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
+ continue;
+
+ /* Check also other adjustment combinations - PR 11786. */
+
+ vaddr = extract_unsigned_integer (buf_vaddr_p, 4,
+ byte_order);
+ vaddr -= displacement;
+ store_unsigned_integer (buf_vaddr_p, 4, byte_order, vaddr);
+
+ paddr = extract_unsigned_integer (buf_paddr_p, 4,
+ byte_order);
+ paddr -= displacement;
+ store_unsigned_integer (buf_paddr_p, 4, byte_order, paddr);
+
+ if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
+ continue;
+
+ /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
+ plt2_asect = bfd_get_section_by_name (exec_bfd, ".plt");
+ if (plt2_asect)
+ {
+ int content2;
+ gdb_byte *buf_filesz_p = (gdb_byte *) &phdrp->p_filesz;
+ CORE_ADDR filesz;
+
+ content2 = (bfd_get_section_flags (exec_bfd, plt2_asect)
+ & SEC_HAS_CONTENTS) != 0;
+
+ filesz = extract_unsigned_integer (buf_filesz_p, 4,
+ byte_order);
+
+ /* PLT2_ASECT is from on-disk file (exec_bfd) while
+ FILESZ is from the in-memory image. */
+ if (content2)
+ filesz += bfd_get_section_size (plt2_asect);
+ else
+ filesz -= bfd_get_section_size (plt2_asect);
+
+ store_unsigned_integer (buf_filesz_p, 4, byte_order,
+ filesz);
+
+ if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
+ continue;
+ }
+
+ ok = 0;
+ break;
+ }
+ }
+ else if (arch_size == 64
+ && phdrs_size >= sizeof (Elf64_External_Phdr)
+ && phdrs_size % sizeof (Elf64_External_Phdr) == 0)
+ {
+ Elf_Internal_Ehdr *ehdr2 = elf_tdata (exec_bfd)->elf_header;
+ Elf_Internal_Phdr *phdr2 = elf_tdata (exec_bfd)->phdr;
+ CORE_ADDR displacement = 0;
+ int i;
+
+ /* DISPLACEMENT could be found more easily by the difference of
+ ehdr2->e_entry. But we haven't read the ehdr yet, and we
+ already have enough information to compute that displacement
+ with what we've read. */
+
+ for (i = 0; i < ehdr2->e_phnum; i++)
+ if (phdr2[i].p_type == PT_LOAD)
+ {
+ Elf64_External_Phdr *phdrp;
+ gdb_byte *buf_vaddr_p, *buf_paddr_p;
+ CORE_ADDR vaddr, paddr;
+ CORE_ADDR displacement_vaddr = 0;
+ CORE_ADDR displacement_paddr = 0;
+
+ phdrp = &((Elf64_External_Phdr *) buf)[i];
+ buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
+ buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
+
+ vaddr = extract_unsigned_integer (buf_vaddr_p, 8,
+ byte_order);
+ displacement_vaddr = vaddr - phdr2[i].p_vaddr;
+
+ paddr = extract_unsigned_integer (buf_paddr_p, 8,
+ byte_order);
+ displacement_paddr = paddr - phdr2[i].p_paddr;
+
+ if (displacement_vaddr == displacement_paddr)
+ displacement = displacement_vaddr;
+
+ break;
+ }
+
+ /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
+
+ for (i = 0; i < phdrs_size / sizeof (Elf64_External_Phdr); i++)
+ {
+ Elf64_External_Phdr *phdrp;
+ Elf64_External_Phdr *phdr2p;
+ gdb_byte *buf_vaddr_p, *buf_paddr_p;
+ CORE_ADDR vaddr, paddr;
+ asection *plt2_asect;
+
+ phdrp = &((Elf64_External_Phdr *) buf)[i];
+ buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
+ buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
+ phdr2p = &((Elf64_External_Phdr *) buf2)[i];
+
+ /* PT_GNU_STACK is an exception by being never relocated by
+ prelink as its addresses are always zero. */
+
+ if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
+ continue;
+
+ /* Check also other adjustment combinations - PR 11786. */
+
+ vaddr = extract_unsigned_integer (buf_vaddr_p, 8,
+ byte_order);
+ vaddr -= displacement;
+ store_unsigned_integer (buf_vaddr_p, 8, byte_order, vaddr);
+
+ paddr = extract_unsigned_integer (buf_paddr_p, 8,
+ byte_order);
+ paddr -= displacement;
+ store_unsigned_integer (buf_paddr_p, 8, byte_order, paddr);
+
+ if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
+ continue;
+
+ /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
+ plt2_asect = bfd_get_section_by_name (exec_bfd, ".plt");
+ if (plt2_asect)
+ {
+ int content2;
+ gdb_byte *buf_filesz_p = (gdb_byte *) &phdrp->p_filesz;
+ CORE_ADDR filesz;
+
+ content2 = (bfd_get_section_flags (exec_bfd, plt2_asect)
+ & SEC_HAS_CONTENTS) != 0;
+
+ filesz = extract_unsigned_integer (buf_filesz_p, 8,
+ byte_order);
+
+ /* PLT2_ASECT is from on-disk file (exec_bfd) while
+ FILESZ is from the in-memory image. */
+ if (content2)
+ filesz += bfd_get_section_size (plt2_asect);
+ else
+ filesz -= bfd_get_section_size (plt2_asect);
+
+ store_unsigned_integer (buf_filesz_p, 8, byte_order,
+ filesz);
+
+ if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
+ continue;
+ }
+
+ ok = 0;
+ break;
+ }
+ }
+ else
+ ok = 0;
+ }
+
+ xfree (buf);
+ xfree (buf2);
+
+ if (!ok)
+ return 0;
+ }
+
+ if (info_verbose)
+ {
+ /* It can be printed repeatedly as there is no easy way to check
+ the executable symbols/file has been already relocated to
+ displacement. */
+
+ printf_unfiltered (_("Using PIE (Position Independent Executable) "
+ "displacement %s for \"%s\".\n"),
+ paddress (target_gdbarch, displacement),
+ bfd_get_filename (exec_bfd));
+ }
+
+ *displacementp = displacement;
+ return 1;
+}
+
+/* Relocate the main executable. This function should be called upon
+ stopping the inferior process at the entry point to the program.
+ The entry point from BFD is compared to the AT_ENTRY of AUXV and if they are
+ different, the main executable is relocated by the proper amount. */
static void
svr4_relocate_main_executable (void)
{
- asection *interp_sect;
- CORE_ADDR pc = read_pc ();
-
- /* Decide if the objfile needs to be relocated. As indicated above,
- we will only be here when execution is stopped at the beginning
- of the program. Relocation is necessary if the address at which
- we are presently stopped differs from the start address stored in
- the executable AND there's no interpreter section. The condition
- regarding the interpreter section is very important because if
- there *is* an interpreter section, execution will begin there
- instead. When there is an interpreter section, the start address
- is (presumably) used by the interpreter at some point to start
- execution of the program.
-
- If there is an interpreter, it is normal for it to be set to an
- arbitrary address at the outset. The job of finding it is
- handled in enable_break().
-
- So, to summarize, relocations are necessary when there is no
- interpreter section and the start address obtained from the
- executable is different from the address at which GDB is
- currently stopped.
-
- [ The astute reader will note that we also test to make sure that
- the executable in question has the DYNAMIC flag set. It is my
- opinion that this test is unnecessary (undesirable even). It
- was added to avoid inadvertent relocation of an executable
- whose e_type member in the ELF header is not ET_DYN. There may
- be a time in the future when it is desirable to do relocations
- on other types of files as well in which case this condition
- should either be removed or modified to accomodate the new file
- type. (E.g, an ET_EXEC executable which has been built to be
- position-independent could safely be relocated by the OS if
- desired. It is true that this violates the ABI, but the ABI
- has been known to be bent from time to time.) - Kevin, Nov 2000. ]
- */
-
- interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
- if (interp_sect == NULL
- && (bfd_get_file_flags (exec_bfd) & DYNAMIC) != 0
- && (exec_entry_point (exec_bfd, &exec_ops) != pc))
+ CORE_ADDR displacement;
+
+ /* If we are re-running this executable, SYMFILE_OBJFILE->SECTION_OFFSETS
+ probably contains the offsets computed using the PIE displacement
+ from the previous run, which of course are irrelevant for this run.
+ So we need to determine the new PIE displacement and recompute the
+ section offsets accordingly, even if SYMFILE_OBJFILE->SECTION_OFFSETS
+ already contains pre-computed offsets.
+
+ If we cannot compute the PIE displacement, either:
+
+ - The executable is not PIE.
+
+ - SYMFILE_OBJFILE does not match the executable started in the target.
+ This can happen for main executable symbols loaded at the host while
+ `ld.so --ld-args main-executable' is loaded in the target.
+
+ Then we leave the section offsets untouched and use them as is for
+ this run. Either:
+
+ - These section offsets were properly reset earlier, and thus
+ already contain the correct values. This can happen for instance
+ when reconnecting via the remote protocol to a target that supports
+ the `qOffsets' packet.
+
+ - The section offsets were not reset earlier, and the best we can
+ hope is that the old offsets are still applicable to the new run. */
+
+ if (! svr4_exec_displacement (&displacement))
+ return;
+
+ /* Even DISPLACEMENT 0 is a valid new difference of in-memory vs. in-file
+ addresses. */
+
+ if (symfile_objfile)
{
- struct cleanup *old_chain;
struct section_offsets *new_offsets;
- int i, changed;
- CORE_ADDR displacement;
-
- /* It is necessary to relocate the objfile. The amount to
- relocate by is simply the address at which we are stopped
- minus the starting address from the executable.
-
- We relocate all of the sections by the same amount. This
- behavior is mandated by recent editions of the System V ABI.
- According to the System V Application Binary Interface,
- Edition 4.1, page 5-5:
-
- ... Though the system chooses virtual addresses for
- individual processes, it maintains the segments' relative
- positions. Because position-independent code uses relative
- addressesing between segments, the difference between
- virtual addresses in memory must match the difference
- between virtual addresses in the file. The difference
- between the virtual address of any segment in memory and
- the corresponding virtual address in the file is thus a
- single constant value for any one executable or shared
- object in a given process. This difference is the base
- address. One use of the base address is to relocate the
- memory image of the program during dynamic linking.
-
- The same language also appears in Edition 4.0 of the System V
- ABI and is left unspecified in some of the earlier editions. */
-
- displacement = pc - exec_entry_point (exec_bfd, &exec_ops);
- changed = 0;
-
- new_offsets = xcalloc (symfile_objfile->num_sections,
- sizeof (struct section_offsets));
- old_chain = make_cleanup (xfree, new_offsets);
+ int i;
+
+ new_offsets = alloca (symfile_objfile->num_sections
+ * sizeof (*new_offsets));
for (i = 0; i < symfile_objfile->num_sections; i++)
- {
- if (displacement != ANOFFSET (symfile_objfile->section_offsets, i))
- changed = 1;
- new_offsets->offsets[i] = displacement;
- }
+ new_offsets->offsets[i] = displacement;
- if (changed)
- objfile_relocate (symfile_objfile, new_offsets);
+ objfile_relocate (symfile_objfile, new_offsets);
+ }
+ else if (exec_bfd)
+ {
+ asection *asect;
- do_cleanups (old_chain);
+ for (asect = exec_bfd->sections; asect != NULL; asect = asect->next)
+ exec_set_section_address (bfd_get_filename (exec_bfd), asect->index,
+ (bfd_section_vma (exec_bfd, asect)
+ + displacement));
}
}
SYNOPSIS
- void svr4_solib_create_inferior_hook ()
+ void svr4_solib_create_inferior_hook (int from_tty)
DESCRIPTION
*/
static void
-svr4_solib_create_inferior_hook (void)
+svr4_solib_create_inferior_hook (int from_tty)
{
+#if defined(_SCO_DS)
+ struct inferior *inf;
+ struct thread_info *tp;
+#endif /* defined(_SCO_DS) */
+ struct svr4_info *info;
+
+ info = get_svr4_info ();
+
/* Relocate the main executable if necessary. */
svr4_relocate_main_executable ();
if (!svr4_have_link_map_offsets ())
- {
- warning (_("no shared library support for this OS / ABI"));
- return;
+ return;
- }
-
- if (!enable_break ())
- {
- warning (_("shared library handler failed to enable breakpoint"));
- return;
- }
+ if (!enable_break (info, from_tty))
+ return;
#if defined(_SCO_DS)
/* SCO needs the loop below, other systems should be using the
Now run the target. It will eventually hit the breakpoint, at
which point all of the libraries will have been mapped in and we
can go groveling around in the dynamic linker structures to find
- out what we need to know about them. */
+ out what we need to know about them. */
+
+ inf = current_inferior ();
+ tp = inferior_thread ();
clear_proceed_status ();
- stop_soon = STOP_QUIETLY;
- stop_signal = TARGET_SIGNAL_0;
+ inf->control.stop_soon = STOP_QUIETLY;
+ tp->suspend.stop_signal = TARGET_SIGNAL_0;
do
{
- target_resume (pid_to_ptid (-1), 0, stop_signal);
- wait_for_inferior ();
+ target_resume (pid_to_ptid (-1), 0, tp->suspend.stop_signal);
+ wait_for_inferior (0);
}
- while (stop_signal != TARGET_SIGNAL_TRAP);
- stop_soon = NO_STOP_QUIETLY;
+ while (tp->suspend.stop_signal != TARGET_SIGNAL_TRAP);
+ inf->control.stop_soon = NO_STOP_QUIETLY;
#endif /* defined(_SCO_DS) */
}
static void
svr4_clear_solib (void)
{
- debug_base = 0;
+ struct svr4_info *info;
+
+ info = get_svr4_info ();
+ info->debug_base = 0;
+ info->debug_loader_offset_p = 0;
+ info->debug_loader_offset = 0;
+ xfree (info->debug_loader_name);
+ info->debug_loader_name = NULL;
}
static void
natural pointer/address correspondence. (For example, on the MIPS,
converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to
sign-extend the value. There, simply truncating the bits above
- TARGET_PTR_BIT, as we do below, is no good.) This should probably
+ gdbarch_ptr_bit, as we do below, is no good.) This should probably
be a new gdbarch method or something. */
static CORE_ADDR
svr4_truncate_ptr (CORE_ADDR addr)
{
- if (TARGET_PTR_BIT == sizeof (CORE_ADDR) * 8)
+ if (gdbarch_ptr_bit (target_gdbarch) == sizeof (CORE_ADDR) * 8)
/* We don't need to truncate anything, and the bit twiddling below
will fail due to overflow problems. */
return addr;
else
- return addr & (((CORE_ADDR) 1 << TARGET_PTR_BIT) - 1);
+ return addr & (((CORE_ADDR) 1 << gdbarch_ptr_bit (target_gdbarch)) - 1);
}
static void
svr4_relocate_section_addresses (struct so_list *so,
- struct section_table *sec)
+ struct target_section *sec)
{
- sec->addr = svr4_truncate_ptr (sec->addr + LM_ADDR (so));
- sec->endaddr = svr4_truncate_ptr (sec->endaddr + LM_ADDR (so));
+ sec->addr = svr4_truncate_ptr (sec->addr + LM_ADDR_CHECK (so,
+ sec->bfd));
+ sec->endaddr = svr4_truncate_ptr (sec->endaddr + LM_ADDR_CHECK (so,
+ sec->bfd));
}
\f
struct solib_svr4_ops *ops;
ops = OBSTACK_ZALLOC (obstack, struct solib_svr4_ops);
- ops->fetch_link_map_offsets = legacy_svr4_fetch_link_map_offsets_hook;
+ ops->fetch_link_map_offsets = NULL;
return ops;
}
/* Set the architecture-specific `struct link_map_offsets' fetcher for
- GDBARCH to FLMO. */
+ GDBARCH to FLMO. Also, install SVR4 solib_ops into GDBARCH. */
void
set_solib_svr4_fetch_link_map_offsets (struct gdbarch *gdbarch,
struct solib_svr4_ops *ops = gdbarch_data (gdbarch, solib_svr4_data);
ops->fetch_link_map_offsets = flmo;
+
+ set_solib_ops (gdbarch, &svr4_so_ops);
}
/* Fetch a link_map_offsets structure using the architecture-specific
static struct link_map_offsets *
svr4_fetch_link_map_offsets (void)
{
- struct solib_svr4_ops *ops = gdbarch_data (current_gdbarch, solib_svr4_data);
+ struct solib_svr4_ops *ops = gdbarch_data (target_gdbarch, solib_svr4_data);
gdb_assert (ops->fetch_link_map_offsets);
return ops->fetch_link_map_offsets ();
static int
svr4_have_link_map_offsets (void)
{
- struct solib_svr4_ops *ops = gdbarch_data (current_gdbarch, solib_svr4_data);
+ struct solib_svr4_ops *ops = gdbarch_data (target_gdbarch, solib_svr4_data);
+
return (ops->fetch_link_map_offsets != NULL);
}
\f
{
lmp = &lmo;
- /* Everything we need is in the first 8 bytes. */
- lmo.r_debug_size = 8;
+ lmo.r_version_offset = 0;
+ lmo.r_version_size = 4;
lmo.r_map_offset = 4;
- lmo.r_map_size = 4;
+ lmo.r_brk_offset = 8;
+ lmo.r_ldsomap_offset = 20;
/* Everything we need is in the first 20 bytes. */
lmo.link_map_size = 20;
lmo.l_addr_offset = 0;
- lmo.l_addr_size = 4;
lmo.l_name_offset = 4;
- lmo.l_name_size = 4;
+ lmo.l_ld_offset = 8;
lmo.l_next_offset = 12;
- lmo.l_next_size = 4;
lmo.l_prev_offset = 16;
- lmo.l_prev_size = 4;
}
return lmp;
{
lmp = &lmo;
- /* Everything we need is in the first 16 bytes. */
- lmo.r_debug_size = 16;
+ lmo.r_version_offset = 0;
+ lmo.r_version_size = 4;
lmo.r_map_offset = 8;
- lmo.r_map_size = 8;
+ lmo.r_brk_offset = 16;
+ lmo.r_ldsomap_offset = 40;
/* Everything we need is in the first 40 bytes. */
lmo.link_map_size = 40;
lmo.l_addr_offset = 0;
- lmo.l_addr_size = 8;
lmo.l_name_offset = 8;
- lmo.l_name_size = 8;
+ lmo.l_ld_offset = 16;
lmo.l_next_offset = 24;
- lmo.l_next_size = 8;
lmo.l_prev_offset = 32;
- lmo.l_prev_size = 8;
}
return lmp;
}
\f
-static struct target_so_ops svr4_so_ops;
+struct target_so_ops svr4_so_ops;
+
+/* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a
+ different rule for symbol lookup. The lookup begins here in the DSO, not in
+ the main executable. */
+
+static struct symbol *
+elf_lookup_lib_symbol (const struct objfile *objfile,
+ const char *name,
+ const domain_enum domain)
+{
+ bfd *abfd;
+
+ if (objfile == symfile_objfile)
+ abfd = exec_bfd;
+ else
+ {
+ /* OBJFILE should have been passed as the non-debug one. */
+ gdb_assert (objfile->separate_debug_objfile_backlink == NULL);
+
+ abfd = objfile->obfd;
+ }
+
+ if (abfd == NULL || scan_dyntag (DT_SYMBOLIC, abfd, NULL) != 1)
+ return NULL;
+
+ return lookup_global_symbol_from_objfile (objfile, name, domain);
+}
extern initialize_file_ftype _initialize_svr4_solib; /* -Wmissing-prototypes */
_initialize_svr4_solib (void)
{
solib_svr4_data = gdbarch_data_register_pre_init (solib_svr4_init);
+ solib_svr4_pspace_data
+ = register_program_space_data_with_cleanup (svr4_pspace_data_cleanup);
svr4_so_ops.relocate_section_addresses = svr4_relocate_section_addresses;
svr4_so_ops.free_so = svr4_free_so;
svr4_so_ops.current_sos = svr4_current_sos;
svr4_so_ops.open_symbol_file_object = open_symbol_file_object;
svr4_so_ops.in_dynsym_resolve_code = svr4_in_dynsym_resolve_code;
-
- /* FIXME: Don't do this here. *_gdbarch_init() should set so_ops. */
- current_target_so_ops = &svr4_so_ops;
+ svr4_so_ops.bfd_open = solib_bfd_open;
+ svr4_so_ops.lookup_lib_global_symbol = elf_lookup_lib_symbol;
+ svr4_so_ops.same = svr4_same;
+ svr4_so_ops.keep_data_in_core = svr4_keep_data_in_core;
}
projects / deliverable / binutils-gdb.git / blobdiff