/* Handle SunOS and SVR4 shared libraries for GDB, the GNU Debugger.
- Copyright 1990, 1991 Free Software Foundation, Inc.
+ Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998
+ Free Software Foundation, Inc.
This file is part of GDB.
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., 675 Mass Ave, Cambridge, MA 02139, USA. */
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+#include "defs.h"
+
+/* This file is only compilable if link.h is available. */
+
+#ifdef HAVE_LINK_H
+
#include <sys/types.h>
#include <signal.h>
-#include <string.h>
-#include <link.h>
+#include "gdb_string.h"
#include <sys/param.h>
#include <fcntl.h>
-#include <stdio.h>
+#include <unistd.h>
+
+#ifndef SVR4_SHARED_LIBS
+ /* SunOS shared libs need the nlist structure. */
+#include <a.out.h>
+#else
+#include "elf/external.h"
+#endif
+
+#include <link.h>
-#include "defs.h"
#include "symtab.h"
+#include "bfd.h"
+#include "symfile.h"
+#include "objfiles.h"
#include "gdbcore.h"
#include "command.h"
#include "target.h"
#include "frame.h"
-#include "regex.h"
+#include "gnu-regex.h"
#include "inferior.h"
+#include "environ.h"
+#include "language.h"
+#include "gdbcmd.h"
+
+#define MAX_PATH_SIZE 512 /* FIXME: Should be dynamic */
+
+/* On SVR4 systems, a list of symbols in the dynamic linker where
+ GDB can try to place a breakpoint to monitor shared library
+ events.
+
+ If none of these symbols are found, or other errors occur, then
+ SVR4 systems will fall back to using a symbol as the "startup
+ mapping complete" breakpoint address. */
+
+#ifdef SVR4_SHARED_LIBS
+static char *solib_break_names[] = {
+ "r_debug_state",
+ "_r_debug_state",
+ "_dl_debug_state",
+ "rtld_db_dlactivity",
+ NULL
+};
+#endif
-extern char *getenv ();
-extern char *elf_interpreter (); /* Interpreter name from exec file */
-extern char *re_comp ();
+#define BKPT_AT_SYMBOL 1
-#define MAX_PATH_SIZE 256 /* FIXME: Should be dynamic */
+#if defined (BKPT_AT_SYMBOL) && defined (SVR4_SHARED_LIBS)
+static char *bkpt_names[] = {
+#ifdef SOLIB_BKPT_NAME
+ SOLIB_BKPT_NAME, /* Prefer configured name if it exists. */
+#endif
+ "_start",
+ "main",
+ NULL
+};
+#endif
-/* On SVR4 systems, for the initial implementation, use main() as the
- "startup mapping complete" breakpoint address. The models for SunOS
- and SVR4 dynamic linking debugger support are different in that SunOS
- hits one breakpoint when all mapping is complete while using the SVR4
- debugger support takes two breakpoint hits for each file mapped, and
- there is no way to know when the "last" one is hit. Both these
- mechanisms should be tied to a "breakpoint service routine" that
- gets automatically executed whenever one of the breakpoints indicating
- a change in mapping is hit. This is a future enhancement. (FIXME) */
+/* Symbols which are used to locate the base of the link map structures. */
-#define BKPT_AT_MAIN 1
+#ifndef SVR4_SHARED_LIBS
+static char *debug_base_symbols[] = {
+ "_DYNAMIC",
+ "_DYNAMIC__MGC",
+ NULL
+};
+#endif
+
+static char *main_name_list[] = {
+ "main_$main",
+ NULL
+};
/* local data declarations */
-#ifdef sun
+#ifndef SVR4_SHARED_LIBS
-#define DEBUG_BASE "_DYNAMIC"
#define LM_ADDR(so) ((so) -> lm.lm_addr)
#define LM_NEXT(so) ((so) -> lm.lm_next)
#define LM_NAME(so) ((so) -> lm.lm_name)
+/* Test for first link map entry; first entry is a shared library. */
+#define IGNORE_FIRST_LINK_MAP_ENTRY(x) (0)
static struct link_dynamic dynamic_copy;
static struct link_dynamic_2 ld_2_copy;
static struct ld_debug debug_copy;
static CORE_ADDR debug_addr;
static CORE_ADDR flag_addr;
-#else /* !sun */
+#else /* SVR4_SHARED_LIBS */
-#define DEBUG_BASE "_r_debug"
#define LM_ADDR(so) ((so) -> lm.l_addr)
#define LM_NEXT(so) ((so) -> lm.l_next)
#define LM_NAME(so) ((so) -> lm.l_name)
+/* Test for first link map entry; first entry is the exec-file. */
+#define IGNORE_FIRST_LINK_MAP_ENTRY(x) ((x).l_prev == NULL)
static struct r_debug debug_copy;
-static CORE_ADDR shlib_base; /* Base address of shared library */
char shadow_contents[BREAKPOINT_MAX]; /* Stash old bkpt addr contents */
-extern CORE_ADDR proc_base_address ();
-extern int proc_address_to_fd ();
-#endif /* sun */
+#endif /* !SVR4_SHARED_LIBS */
struct so_list {
struct so_list *next; /* next structure in linked list */
char so_name[MAX_PATH_SIZE]; /* shared object lib name (FIXME) */
char symbols_loaded; /* flag: symbols read in yet? */
char from_tty; /* flag: print msgs? */
- bfd *so_bfd; /* bfd for so_name */
+ struct objfile *objfile; /* objfile for loaded lib */
struct section_table *sections;
struct section_table *sections_end;
+ struct section_table *textsection;
+ bfd *abfd;
};
static struct so_list *so_list_head; /* List of known shared objects */
static CORE_ADDR debug_base; /* Base of dynamic linker structures */
static CORE_ADDR breakpoint_addr; /* Address where end bkpt is set */
+static int solib_cleanup_queued = 0; /* make_run_cleanup called */
+
+extern int
+fdmatch PARAMS ((int, int)); /* In libiberty */
+
+/* Local function prototypes */
+
+static void
+do_clear_solib PARAMS ((PTR));
+
+static int
+match_main PARAMS ((char *));
+
+static void
+special_symbol_handling PARAMS ((struct so_list *));
+
+static void
+sharedlibrary_command PARAMS ((char *, int));
+
+static int
+enable_break PARAMS ((void));
+
+static void
+info_sharedlibrary_command PARAMS ((char *, int));
+
+static int
+symbol_add_stub PARAMS ((char *));
+
+static struct so_list *
+find_solib PARAMS ((struct so_list *));
+
+static struct link_map *
+first_link_map_member PARAMS ((void));
+
+static CORE_ADDR
+locate_base PARAMS ((void));
+
+static void
+solib_map_sections PARAMS ((struct so_list *));
+
+#ifdef SVR4_SHARED_LIBS
+
+static CORE_ADDR
+elf_locate_base PARAMS ((void));
+
+#else
+
+static int
+disable_break PARAMS ((void));
+
+static void
+allocate_rt_common_objfile PARAMS ((void));
+
+static void
+solib_add_common_symbols PARAMS ((struct rtc_symb *));
+
+#endif
+
+/* If non-zero, this is a prefix that will be added to the front of the name
+ shared libraries with an absolute filename for loading. */
+static char *solib_absolute_prefix = NULL;
+
+/* If non-empty, this is a search path for loading non-absolute shared library
+ symbol files. This takes precedence over the environment variables PATH
+ and LD_LIBRARY_PATH. */
+static char *solib_search_path = NULL;
/*
char *scratch_pathname;
int scratch_chan;
struct section_table *p;
+ struct cleanup *old_chain;
+ bfd *abfd;
filename = tilde_expand (so -> so_name);
- make_cleanup (free, filename);
- scratch_chan = openp (getenv ("PATH"), 1, filename, O_RDONLY, 0,
- &scratch_pathname);
+ if (solib_absolute_prefix && ROOTED_P (filename))
+ /* Prefix shared libraries with absolute filenames with
+ SOLIB_ABSOLUTE_PREFIX. */
+ {
+ char *pfxed_fn;
+ int pfx_len;
+
+ pfx_len = strlen (solib_absolute_prefix);
+
+ /* Remove trailing slashes. */
+ while (pfx_len > 0 && SLASH_P (solib_absolute_prefix[pfx_len - 1]))
+ pfx_len--;
+
+ pfxed_fn = xmalloc (pfx_len + strlen (filename) + 1);
+ strcpy (pfxed_fn, solib_absolute_prefix);
+ strcat (pfxed_fn, filename);
+ free (filename);
+
+ filename = pfxed_fn;
+ }
+
+ old_chain = make_cleanup (free, filename);
+
+ scratch_chan = -1;
+
+ if (solib_search_path)
+ scratch_chan = openp (solib_search_path,
+ 1, filename, O_RDONLY, 0, &scratch_pathname);
+ if (scratch_chan < 0)
+ scratch_chan = openp (get_in_environ (inferior_environ, "PATH"),
+ 1, filename, O_RDONLY, 0, &scratch_pathname);
if (scratch_chan < 0)
{
- scratch_chan = openp (getenv ("LD_LIBRARY_PATH"), 1, filename,
- O_RDONLY, 0, &scratch_pathname);
+ scratch_chan = openp (get_in_environ
+ (inferior_environ, "LD_LIBRARY_PATH"),
+ 1, filename, O_RDONLY, 0, &scratch_pathname);
}
if (scratch_chan < 0)
{
perror_with_name (filename);
- }
+ }
+ /* Leave scratch_pathname allocated. abfd->name will point to it. */
- so -> so_bfd = bfd_fdopenr (scratch_pathname, NULL, scratch_chan);
- if (!so -> so_bfd)
+ abfd = bfd_fdopenr (scratch_pathname, gnutarget, scratch_chan);
+ if (!abfd)
{
+ close (scratch_chan);
error ("Could not open `%s' as an executable file: %s",
- scratch_pathname, bfd_errmsg (bfd_error));
+ scratch_pathname, bfd_errmsg (bfd_get_error ()));
}
- if (!bfd_check_format (so -> so_bfd, bfd_object))
+ /* Leave bfd open, core_xfer_memory and "info files" need it. */
+ so -> abfd = abfd;
+ abfd -> cacheable = true;
+
+ /* copy full path name into so_name, so that later symbol_file_add can find
+ it */
+ if (strlen (scratch_pathname) >= MAX_PATH_SIZE)
+ error ("Full path name length of shared library exceeds MAX_PATH_SIZE in so_list structure.");
+ strcpy (so->so_name, scratch_pathname);
+
+ if (!bfd_check_format (abfd, bfd_object))
{
error ("\"%s\": not in executable format: %s.",
- scratch_pathname, bfd_errmsg (bfd_error));
+ scratch_pathname, bfd_errmsg (bfd_get_error ()));
}
- if (build_section_table (so -> so_bfd, &so -> sections, &so -> sections_end))
+ if (build_section_table (abfd, &so -> sections, &so -> sections_end))
{
error ("Can't find the file sections in `%s': %s",
- exec_bfd -> filename, bfd_errmsg (bfd_error));
+ bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
}
for (p = so -> sections; p < so -> sections_end; p++)
p -> addr += (CORE_ADDR) LM_ADDR (so);
p -> endaddr += (CORE_ADDR) LM_ADDR (so);
so -> lmend = (CORE_ADDR) max (p -> endaddr, so -> lmend);
+ if (STREQ (p -> the_bfd_section -> name, ".text"))
+ {
+ so -> textsection = p;
+ }
+ }
+
+ /* Free the file names, close the file now. */
+ do_cleanups (old_chain);
+}
+
+#ifndef SVR4_SHARED_LIBS
+
+/* Allocate the runtime common object file. */
+
+static void
+allocate_rt_common_objfile ()
+{
+ struct objfile *objfile;
+ struct objfile *last_one;
+
+ objfile = (struct objfile *) xmalloc (sizeof (struct objfile));
+ memset (objfile, 0, sizeof (struct objfile));
+ objfile -> md = NULL;
+ obstack_specify_allocation (&objfile -> psymbol_cache.cache, 0, 0,
+ xmalloc, free);
+ obstack_specify_allocation (&objfile -> psymbol_obstack, 0, 0, xmalloc,
+ free);
+ obstack_specify_allocation (&objfile -> symbol_obstack, 0, 0, xmalloc,
+ free);
+ obstack_specify_allocation (&objfile -> type_obstack, 0, 0, xmalloc,
+ free);
+ objfile -> name = mstrsave (objfile -> md, "rt_common");
+
+ /* Add this file onto the tail of the linked list of other such files. */
+
+ objfile -> next = NULL;
+ if (object_files == NULL)
+ object_files = objfile;
+ else
+ {
+ for (last_one = object_files;
+ last_one -> next;
+ last_one = last_one -> next);
+ last_one -> next = objfile;
}
+
+ rt_common_objfile = objfile;
}
+/* Read all dynamically loaded common symbol definitions from the inferior
+ and put them into the minimal symbol table for the runtime common
+ objfile. */
+
+static void
+solib_add_common_symbols (rtc_symp)
+ struct rtc_symb *rtc_symp;
+{
+ struct rtc_symb inferior_rtc_symb;
+ struct nlist inferior_rtc_nlist;
+ int len;
+ char *name;
+
+ /* Remove any runtime common symbols from previous runs. */
+
+ if (rt_common_objfile != NULL && rt_common_objfile -> minimal_symbol_count)
+ {
+ obstack_free (&rt_common_objfile -> symbol_obstack, 0);
+ obstack_specify_allocation (&rt_common_objfile -> symbol_obstack, 0, 0,
+ xmalloc, free);
+ rt_common_objfile -> minimal_symbol_count = 0;
+ rt_common_objfile -> msymbols = NULL;
+ }
+
+ init_minimal_symbol_collection ();
+ make_cleanup (discard_minimal_symbols, 0);
+
+ while (rtc_symp)
+ {
+ read_memory ((CORE_ADDR) rtc_symp,
+ (char *) &inferior_rtc_symb,
+ sizeof (inferior_rtc_symb));
+ read_memory ((CORE_ADDR) inferior_rtc_symb.rtc_sp,
+ (char *) &inferior_rtc_nlist,
+ sizeof(inferior_rtc_nlist));
+ if (inferior_rtc_nlist.n_type == N_COMM)
+ {
+ /* FIXME: The length of the symbol name is not available, but in the
+ current implementation the common symbol is allocated immediately
+ behind the name of the symbol. */
+ len = inferior_rtc_nlist.n_value - inferior_rtc_nlist.n_un.n_strx;
+
+ name = xmalloc (len);
+ read_memory ((CORE_ADDR) inferior_rtc_nlist.n_un.n_name, name, len);
+
+ /* Allocate the runtime common objfile if necessary. */
+ if (rt_common_objfile == NULL)
+ allocate_rt_common_objfile ();
+
+ prim_record_minimal_symbol (name, inferior_rtc_nlist.n_value,
+ mst_bss, rt_common_objfile);
+ free (name);
+ }
+ rtc_symp = inferior_rtc_symb.rtc_next;
+ }
+
+ /* Install any minimal symbols that have been collected as the current
+ minimal symbols for the runtime common objfile. */
+
+ install_minimal_symbols (rt_common_objfile);
+}
+
+#endif /* SVR4_SHARED_LIBS */
+
+
+#ifdef SVR4_SHARED_LIBS
+
+static CORE_ADDR
+bfd_lookup_symbol PARAMS ((bfd *, char *));
+
/*
LOCAL FUNCTION
Note that 0 is specifically allowed as an error return (no
such symbol).
-
- FIXME: See if there is a less "expensive" way of doing this.
- Also see if there is already another bfd or gdb function
- that specifically does this, and if so, use it.
*/
static CORE_ADDR
-DEFUN (bfd_lookup_symbol, (abfd, symname),
- bfd *abfd AND
- char *symname)
+bfd_lookup_symbol (abfd, symname)
+ bfd *abfd;
+ char *symname;
{
unsigned int storage_needed;
asymbol *sym;
unsigned int i;
struct cleanup *back_to;
CORE_ADDR symaddr = 0;
- enum misc_function_type mf_type;
- storage_needed = get_symtab_upper_bound (abfd);
+ storage_needed = bfd_get_symtab_upper_bound (abfd);
if (storage_needed > 0)
{
- symbol_table = (asymbol **) bfd_xmalloc (storage_needed);
- back_to = make_cleanup (free, symbol_table);
+ symbol_table = (asymbol **) xmalloc (storage_needed);
+ back_to = make_cleanup (free, (PTR)symbol_table);
number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
for (i = 0; i < number_of_symbols; i++)
{
sym = *symbol_table++;
- if (strcmp (sym -> name, symname) == 0)
+ if (STREQ (sym -> name, symname))
{
- symaddr = sym -> value;
+ /* Bfd symbols are section relative. */
+ symaddr = sym -> value + sym -> section -> vma;
break;
}
}
return (symaddr);
}
+#ifdef HANDLE_SVR4_EXEC_EMULATORS
+
/*
+ Solaris BCP (the part of Solaris which allows it to run SunOS4
+ a.out files) throws in another wrinkle. Solaris does not fill
+ in the usual a.out link map structures when running BCP programs,
+ the only way to get at them is via groping around in the dynamic
+ linker.
+ The dynamic linker and it's structures are located in the shared
+ C library, which gets run as the executable's "interpreter" by
+ the kernel.
+
+ Note that we can assume nothing about the process state at the time
+ we need to find these structures. We may be stopped on the first
+ instruction of the interpreter (C shared library), the first
+ instruction of the executable itself, or somewhere else entirely
+ (if we attached to the process for example).
+*/
-LOCAL FUNCTION
+static char *debug_base_symbols[] = {
+ "r_debug", /* Solaris 2.3 */
+ "_r_debug", /* Solaris 2.1, 2.2 */
+ NULL
+};
- locate_base -- locate the base address of dynamic linker structs
+static int
+look_for_base PARAMS ((int, CORE_ADDR));
-SYNOPSIS
+/*
- CORE_ADDR locate_base (void)
+LOCAL FUNCTION
-DESCRIPTION
+ look_for_base -- examine file for each mapped address segment
- For both the SunOS and SVR4 shared library implementations, if the
- inferior executable has been linked dynamically, there is a single
- address somewhere in the inferior's data space which is the key to
- locating all of the dynamic linker's runtime structures, and this
- address is the value of the symbol defined by the macro DEBUG_BASE.
- The job of this function is to find and return that address, or to
- return 0 if there is no such address (the executable is statically
- linked for example).
+SYNOPSYS
- For SunOS, the job is almost trivial, since the dynamic linker and
- all of it's structures are statically linked to the executable at
- link time. Thus the symbol for the address we are looking for has
- already been added to the misc function vector at the time the symbol
- file's symbols were read.
-
- The SVR4 version is much more complicated because the dynamic linker
- and it's structures are located in the shared library itself, which
- gets run as the executable's "interpreter" by the kernel. Because
- of this complexity, we cache the value we find and return that value
- on subsequent invocations, if it is non-zero.
-
- First we must decide if we are stopped at the entry point of the
- shared C library, which is set to be the entry point of the dynamic
- linker code (the function _rt_boot() to be precise), or at the entry
- point given in the inferior's exec file (for statically linked
- executables).
-
- If we are not stopped at the inferior's exec file entry point then
- we are either stopped at the interpreter's entry point or somewhere
- else (I.E. totally lost). Use the /proc interface to get an open
- file descriptor on the file that is mapped at the current stop_pc
- value and try to open a bfd for it.
+ static int look_for_base (int fd, CORE_ADDR baseaddr)
-FIXME
+DESCRIPTION
- The SVR4 strategy does NOT work when gdb is attaching to an existing
- process because the stop_pc is not in the library code, so we can't
- use the /proc interface to get an open fd for the library. So we
- need to rethink the method for finding the debugger interface struct.
+ This function is passed to proc_iterate_over_mappings, which
+ causes it to get called once for each mapped address space, with
+ an open file descriptor for the file mapped to that space, and the
+ base address of that mapped space.
- For SunOS we could look around in the executable code to find
- DEBUG_BASE, if it isn't in the symbol table. It's not that hard to
- find. Then we can debug stripped executables using shared library
- symbols.
+ Our job is to find the debug base symbol in the file that this
+ fd is open on, if it exists, and if so, initialize the dynamic
+ linker structure base address debug_base.
+ Note that this is a computationally expensive proposition, since
+ we basically have to open a bfd on every call, so we specifically
+ avoid opening the exec file.
*/
-static CORE_ADDR
-locate_base ()
+static int
+look_for_base (fd, baseaddr)
+ int fd;
+ CORE_ADDR baseaddr;
{
- CORE_ADDR address;
-
-#ifdef sun
+ bfd *interp_bfd;
+ CORE_ADDR address = 0;
+ char **symbolp;
- int i;
+ /* If the fd is -1, then there is no file that corresponds to this
+ mapped memory segment, so skip it. Also, if the fd corresponds
+ to the exec file, skip it as well. */
- i = lookup_misc_func (DEBUG_BASE);
- if (i >= 0 && misc_function_vector[i].address != 0)
+ if (fd == -1
+ || (exec_bfd != NULL
+ && fdmatch (fileno ((GDB_FILE *)(exec_bfd -> iostream)), fd)))
{
- address = misc_function_vector[i].address;
+ return (0);
}
-#else /* !sun */
+ /* Try to open whatever random file this fd corresponds to. Note that
+ we have no way currently to find the filename. Don't gripe about
+ any problems we might have, just fail. */
- int stop_pc_fd; /* File descriptor for mapped file */
- int interp_fd; /* File descriptor for interpreter */
- char *interp_name; /* Name of interpreter */
- char *full_interp_name; /* Full pathname of interpreter */
- bfd *interp_bfd;
- CORE_ADDR interp_base;
-
- if (debug_base > 0)
- {
- /* We have a currently valid address, so avoid doing all the work
- again. */
- return (debug_base);
- }
- if (bfd_get_start_address (exec_bfd) == stop_pc)
+ if ((interp_bfd = bfd_fdopenr ("unnamed", gnutarget, fd)) == NULL)
{
- /* We are stopped at the entry point to the exec file, so there
- are no shared libs to deal with. */
return (0);
}
- if ((stop_pc_fd = proc_address_to_fd (stop_pc)) < 0)
+ if (!bfd_check_format (interp_bfd, bfd_object))
{
- /* We are stopped at an address for which we can't seem to get an open
- file descriptor from the /proc interface. We should already have
- printed a suitable warning message. */
+ /* FIXME-leak: on failure, might not free all memory associated with
+ interp_bfd. */
+ bfd_close (interp_bfd);
return (0);
}
- if ((interp_name = elf_interpreter (exec_bfd)) == NULL)
+
+ /* Now try to find our debug base symbol in this file, which we at
+ least know to be a valid ELF executable or shared library. */
+
+ for (symbolp = debug_base_symbols; *symbolp != NULL; symbolp++)
{
- /* There is no interpreter specified in the exec file, thus this is
- not a normal dynamically linked file. */
- return (0);
+ address = bfd_lookup_symbol (interp_bfd, *symbolp);
+ if (address != 0)
+ {
+ break;
+ }
}
- if ((interp_fd = openp (getenv ("PATH"), 1, interp_name, O_RDONLY, 0,
- &full_interp_name)) < 0)
+ if (address == 0)
{
- /* We can't find and open the interpreter. This is a problem. */
+ /* FIXME-leak: on failure, might not free all memory associated with
+ interp_bfd. */
+ bfd_close (interp_bfd);
return (0);
}
- if (!fdmatch (stop_pc_fd, interp_fd))
+
+ /* Eureka! We found the symbol. But now we may need to relocate it
+ by the base address. If the symbol's value is less than the base
+ address of the shared library, then it hasn't yet been relocated
+ by the dynamic linker, and we have to do it ourself. FIXME: Note
+ that we make the assumption that the first segment that corresponds
+ to the shared library has the base address to which the library
+ was relocated. */
+
+ if (address < baseaddr)
{
- /* The file for the mapped region is not the interpreter, something
- is strange... */
- close (stop_pc_fd);
- close (interp_fd);
- free (full_interp_name);
- return (0);
+ address += baseaddr;
}
- interp_bfd = bfd_fdopenr (full_interp_name, NULL, interp_fd);
- if (!interp_bfd)
+ debug_base = address;
+ /* FIXME-leak: on failure, might not free all memory associated with
+ interp_bfd. */
+ bfd_close (interp_bfd);
+ return (1);
+}
+#endif /* HANDLE_SVR4_EXEC_EMULATORS */
+
+/*
+
+LOCAL FUNCTION
+
+ elf_locate_base -- locate the base address of dynamic linker structs
+ for SVR4 elf targets.
+
+SYNOPSIS
+
+ CORE_ADDR elf_locate_base (void)
+
+DESCRIPTION
+
+ For SVR4 elf targets the address of the dynamic linker's runtime
+ structure is contained within the dynamic info section in the
+ executable file. The dynamic section is also mapped into the
+ inferior address space. Because the runtime loader fills in the
+ real address before starting the inferior, we have to read in the
+ dynamic info section from the inferior address space.
+ If there are any errors while trying to find the address, we
+ silently return 0, otherwise the found address is returned.
+
+ */
+
+static CORE_ADDR
+elf_locate_base ()
+{
+ sec_ptr dyninfo_sect;
+ int dyninfo_sect_size;
+ CORE_ADDR dyninfo_addr;
+ char *buf;
+ char *bufend;
+
+ /* 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. */
+#ifndef TARGET_ELF64
+ for (bufend = buf + dyninfo_sect_size;
+ buf < bufend;
+ buf += sizeof (Elf32_External_Dyn))
{
- warning ("Could not open `%s' as an executable file: %s",
- full_interp_name, bfd_errmsg (bfd_error));
- return (0);
+ Elf32_External_Dyn *x_dynp = (Elf32_External_Dyn *)buf;
+ long dyn_tag;
+ 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;
+ }
+#ifdef DT_MIPS_RLD_MAP
+ else if (dyn_tag == DT_MIPS_RLD_MAP)
+ {
+ char pbuf[TARGET_PTR_BIT / HOST_CHAR_BIT];
+
+ /* 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, sizeof (pbuf)))
+ return 0;
+ return extract_unsigned_integer (pbuf, sizeof (pbuf));
+ }
+#endif
}
- if (!bfd_check_format (interp_bfd, bfd_object))
+#else /* ELF64 */
+ for (bufend = buf + dyninfo_sect_size;
+ buf < bufend;
+ buf += sizeof (Elf64_External_Dyn))
{
- warning ("\"%s\": not in executable format: %s.",
- full_interp_name, bfd_errmsg (bfd_error));
- return (0);
+ 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;
+ }
}
+#endif
- /* Lookup the unrelocated value of the symbol that defines the location
- of the debugger interface structure for the dynamic linker in the shared
- library. Then find the base address of the text segment in the
- inferior's mapped in dynamic library, which gives the relocation to
- apply to find the actual mapped address of the debugger interface
- structure. */
+ /* DT_DEBUG entry not found. */
+ return 0;
+}
- if ((address = bfd_lookup_symbol (interp_bfd, DEBUG_BASE)) == 0)
- {
- warning ("can't find symbol %s in shared library", DEBUG_BASE);
- return (0);
- }
- if ((interp_base = proc_base_address (stop_pc)) == 0)
+#endif /* SVR4_SHARED_LIBS */
+
+/*
+
+LOCAL FUNCTION
+
+ locate_base -- locate the base address of dynamic linker structs
+
+SYNOPSIS
+
+ CORE_ADDR locate_base (void)
+
+DESCRIPTION
+
+ For both the SunOS and SVR4 shared library implementations, if the
+ inferior executable has been linked dynamically, there is a single
+ address somewhere in the inferior's data space which is the key to
+ locating all of the dynamic linker's runtime structures. This
+ address is the value of the debug base symbol. The job of this
+ function is to find and return that address, or to return 0 if there
+ is no such address (the executable is statically linked for example).
+
+ For SunOS, the job is almost trivial, since the dynamic linker and
+ all of it's structures are statically linked to the executable at
+ link time. Thus the symbol for the address we are looking for has
+ already been added to the minimal symbol table for the executable's
+ objfile at the time the symbol file's symbols were read, and all we
+ have to do is look it up there. Note that we explicitly do NOT want
+ to find the copies in the shared library.
+
+ The SVR4 version is a bit more complicated because the address
+ is contained somewhere in the dynamic info section. We have to go
+ to a lot more work to discover the address of the debug base symbol.
+ Because of this complexity, we cache the value we find and return that
+ value on subsequent invocations. Note there is no copy in the
+ executable symbol tables.
+
+ */
+
+static CORE_ADDR
+locate_base ()
+{
+
+#ifndef SVR4_SHARED_LIBS
+
+ struct minimal_symbol *msymbol;
+ CORE_ADDR address = 0;
+ char **symbolp;
+
+ /* For SunOS, we want to limit the search for the debug base symbol to the
+ executable being debugged, since there is a duplicate named symbol in the
+ shared library. We don't want the shared library versions. */
+
+ for (symbolp = debug_base_symbols; *symbolp != NULL; symbolp++)
{
- warning ("can't find base address for shared library text segment");
- return (0);
+ msymbol = lookup_minimal_symbol (*symbolp, NULL, symfile_objfile);
+ if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
+ {
+ address = SYMBOL_VALUE_ADDRESS (msymbol);
+ return (address);
+ }
}
- shlib_base = interp_base;
- address += interp_base;
+ return (0);
+
+#else /* SVR4_SHARED_LIBS */
- if ((interp_base + bfd_get_start_address (interp_bfd)) != stop_pc)
+ /* 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
+ we have no cached address, try to locate it in the dynamic info
+ section for ELF executables. */
+
+ if (debug_base == 0)
{
- /* We are not stopped at the entry point to the dynamic linker,
- so grumble and skip startup shared library processing. */
- warning ("not stopped at entry point of dynamic linker");
- warning ("shared library processing suppressed");
- return (0);
+ if (exec_bfd != NULL
+ && bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
+ debug_base = elf_locate_base ();
+#ifdef HANDLE_SVR4_EXEC_EMULATORS
+ /* Try it the hard way for emulated executables. */
+ else if (inferior_pid != 0 && target_has_execution)
+ proc_iterate_over_mappings (look_for_base);
+#endif
}
+ return (debug_base);
- bfd_close (interp_bfd);
+#endif /* !SVR4_SHARED_LIBS */
+
+}
-#endif /* sun */
+/*
- return (address);
+LOCAL FUNCTION
-}
+ first_link_map_member -- locate first member in dynamic linker's map
+
+SYNOPSIS
+
+ static struct link_map *first_link_map_member (void)
+
+DESCRIPTION
+
+ Read in a copy of the first member in the inferior's dynamic
+ link map from the inferior's dynamic linker structures, and return
+ a pointer to the copy in our address space.
+*/
static struct link_map *
first_link_map_member ()
{
struct link_map *lm = NULL;
-#ifdef sun
+#ifndef SVR4_SHARED_LIBS
- read_memory (debug_base, &dynamic_copy, sizeof (dynamic_copy));
+ read_memory (debug_base, (char *) &dynamic_copy, sizeof (dynamic_copy));
if (dynamic_copy.ld_version >= 2)
{
/* It is a version that we can deal with, so read in the secondary
structure and find the address of the link map list from it. */
- read_memory ((CORE_ADDR) dynamic_copy.ld_un.ld_2, &ld_2_copy,
+ read_memory ((CORE_ADDR) dynamic_copy.ld_un.ld_2, (char *) &ld_2_copy,
sizeof (struct link_dynamic_2));
lm = ld_2_copy.ld_loaded;
}
-#else
+#else /* SVR4_SHARED_LIBS */
- read_memory (debug_base, &debug_copy, sizeof (struct r_debug));
+ read_memory (debug_base, (char *) &debug_copy, sizeof (struct r_debug));
+ /* FIXME: Perhaps we should validate the info somehow, perhaps by
+ checking r_version for a known version number, or r_state for
+ RT_CONSISTENT. */
lm = debug_copy.r_map;
-#endif
+#endif /* !SVR4_SHARED_LIBS */
return (lm);
}
/*
-GLOBAL FUNCTION
+LOCAL FUNCTION
find_solib -- step through list of shared objects
in <link.h>.
*/
-struct so_list *
+static struct so_list *
find_solib (so_list_ptr)
struct so_list *so_list_ptr; /* Last lm or NULL for first one */
{
/* We have not already read in the dynamic linking structures
from the inferior, lookup the address of the base structure. */
debug_base = locate_base ();
- if (debug_base > 0)
+ if (debug_base != 0)
{
/* Read the base structure in and find the address of the first
link map list member. */
/* Get next link map structure from inferior image and build a local
abbreviated load_map structure */
new = (struct so_list *) xmalloc (sizeof (struct so_list));
- (void) memset ((char *) new, 0, sizeof (struct so_list));
+ memset ((char *) new, 0, sizeof (struct so_list));
new -> lmaddr = lm;
/* Add the new node as the next node in the list, or as the root
node if this is the first one. */
else
{
so_list_head = new;
+
+ if (! solib_cleanup_queued)
+ {
+ make_run_cleanup (do_clear_solib);
+ solib_cleanup_queued = 1;
+ }
+
}
so_list_next = new;
- read_memory ((CORE_ADDR) lm, &(new -> lm), sizeof (struct link_map));
- /* For the SVR4 version, there is one entry that has no name
- (for the inferior executable) since it is not a shared object. */
- if (LM_NAME (new) != 0)
+ read_memory ((CORE_ADDR) lm, (char *) &(new -> lm),
+ sizeof (struct link_map));
+ /* 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 -> lm))
{
- read_memory((CORE_ADDR) LM_NAME (new), new -> so_name,
- MAX_PATH_SIZE - 1);
- new -> so_name[MAX_PATH_SIZE - 1] = 0;
+ int errcode;
+ char *buffer;
+ target_read_string ((CORE_ADDR) LM_NAME (new), &buffer,
+ MAX_PATH_SIZE - 1, &errcode);
+ if (errcode != 0)
+ error ("find_solib: Can't read pathname for load map: %s\n",
+ safe_strerror (errcode));
+ strncpy (new -> so_name, buffer, MAX_PATH_SIZE - 1);
+ new -> so_name[MAX_PATH_SIZE - 1] = '\0';
+ free (buffer);
solib_map_sections (new);
}
}
char *arg;
{
register struct so_list *so = (struct so_list *) arg; /* catch_errs bogon */
+ CORE_ADDR text_addr = 0;
+
+ if (so -> textsection)
+ text_addr = so -> textsection -> addr;
+ else
+ {
+ asection *lowest_sect;
+
+ /* If we didn't find a mapped non zero sized .text section, set up
+ text_addr so that the relocation in symbol_file_add does no harm. */
+
+ lowest_sect = bfd_get_section_by_name (so -> abfd, ".text");
+ if (lowest_sect == NULL)
+ bfd_map_over_sections (so -> abfd, find_lowest_section,
+ (PTR) &lowest_sect);
+ if (lowest_sect)
+ text_addr = bfd_section_vma (so -> abfd, lowest_sect)
+ + (CORE_ADDR) LM_ADDR (so);
+ }
- symbol_file_add (so -> so_name, so -> from_tty,
- (unsigned int) LM_ADDR (so), 0);
+ ALL_OBJFILES (so -> objfile)
+ {
+ if (strcmp (so -> objfile -> name, so -> so_name) == 0)
+ return 1;
+ }
+ so -> objfile =
+ symbol_file_add (so -> so_name, so -> from_tty,
+ text_addr,
+ 0, 0, 0);
return (1);
}
+/* This function will check the so name to see if matches the main list.
+ In some system the main object is in the list, which we want to exclude */
+
+static int match_main (soname)
+ char *soname;
+{
+ char **mainp;
+
+ for (mainp = main_name_list; *mainp != NULL; mainp++)
+ {
+ if (strcmp (soname, *mainp) == 0)
+ return (1);
+ }
+
+ return (0);
+}
+
/*
GLOBAL FUNCTION
struct target_ops *target;
{
register struct so_list *so = NULL; /* link map state variable */
+
+ /* Last shared library that we read. */
+ struct so_list *so_last = NULL;
+
char *re_err;
int count;
int old;
error ("Invalid regexp: %s", re_err);
}
- /* Getting new symbols may change our opinion about what is
- frameless. */
- reinit_frame_cache ();
-
- while ((so = find_solib (so)) != NULL)
- {
- if (so -> so_name[0] && re_exec (so -> so_name))
- {
- if (so -> symbols_loaded)
- {
- if (from_tty)
- {
- printf ("Symbols already loaded for %s\n", so -> so_name);
- }
- }
- else
- {
- so -> symbols_loaded = 1;
- so -> from_tty = from_tty;
- catch_errors (symbol_add_stub, (char *) so,
- "Error while reading shared library symbols:\n");
- }
- }
- }
-
- /* Now add the shared library sections to the section table of the
+ /* Add the shared library sections to the section table of the
specified target, if any. */
if (target)
{
count = 0;
while ((so = find_solib (so)) != NULL)
{
- if (so -> so_name[0])
+ if (so -> so_name[0] && !match_main (so -> so_name))
{
count += so -> sections_end - so -> sections;
}
if (count)
{
+ int update_coreops;
+
+ /* We must update the to_sections field in the core_ops structure
+ here, otherwise we dereference a potential dangling pointer
+ for each call to target_read/write_memory within this routine. */
+ update_coreops = core_ops.to_sections == target->to_sections;
+
/* Reallocate the target's section table including the new size. */
- if (target -> sections)
+ if (target -> to_sections)
{
- old = target -> sections_end - target -> sections;
- target -> sections = (struct section_table *)
- realloc ((char *)target -> sections,
+ old = target -> to_sections_end - target -> to_sections;
+ target -> to_sections = (struct section_table *)
+ xrealloc ((char *)target -> to_sections,
(sizeof (struct section_table)) * (count + old));
}
else
{
old = 0;
- target -> sections = (struct section_table *)
- malloc ((sizeof (struct section_table)) * count);
+ target -> to_sections = (struct section_table *)
+ xmalloc ((sizeof (struct section_table)) * count);
}
- target -> sections_end = target -> sections + (count + old);
+ target -> to_sections_end = target -> to_sections + (count + old);
+ /* Update the to_sections field in the core_ops structure
+ if needed. */
+ if (update_coreops)
+ {
+ core_ops.to_sections = target->to_sections;
+ core_ops.to_sections_end = target->to_sections_end;
+ }
+
/* Add these section table entries to the target's table. */
while ((so = find_solib (so)) != NULL)
{
if (so -> so_name[0])
{
count = so -> sections_end - so -> sections;
- bcopy (so -> sections, (char *)(target -> sections + old),
- (sizeof (struct section_table)) * count);
+ memcpy ((char *) (target -> to_sections + old),
+ so -> sections,
+ (sizeof (struct section_table)) * count);
old += count;
}
}
}
}
+
+ /* Now add the symbol files. */
+ while ((so = find_solib (so)) != NULL)
+ {
+ if (so -> so_name[0] && re_exec (so -> so_name) &&
+ !match_main (so -> so_name))
+ {
+ so -> from_tty = from_tty;
+ if (so -> symbols_loaded)
+ {
+ if (from_tty)
+ {
+ printf_unfiltered ("Symbols already loaded for %s\n", so -> so_name);
+ }
+ }
+ else if (catch_errors
+ (symbol_add_stub, (char *) so,
+ "Error while reading shared library symbols:\n",
+ RETURN_MASK_ALL))
+ {
+ so_last = so;
+ so -> symbols_loaded = 1;
+ }
+ }
+ }
+
+ /* Getting new symbols may change our opinion about what is
+ frameless. */
+ if (so_last)
+ reinit_frame_cache ();
+
+ if (so_last)
+ special_symbol_handling (so_last);
}
/*
*/
static void
-info_sharedlibrary_command ()
+info_sharedlibrary_command (ignore, from_tty)
+ char *ignore;
+ int from_tty;
{
register struct so_list *so = NULL; /* link map state variable */
int header_done = 0;
-
+ int addr_width;
+ char *addr_fmt;
+
if (exec_bfd == NULL)
{
- printf ("No exec file.\n");
+ printf_unfiltered ("No exec file.\n");
return;
}
+
+#ifndef TARGET_ELF64
+ addr_width = 8+4;
+ addr_fmt = "08l";
+#else
+ addr_width = 16+4;
+ addr_fmt = "016l";
+#endif
+
while ((so = find_solib (so)) != NULL)
{
if (so -> so_name[0])
{
if (!header_done)
{
- printf("%-12s%-12s%-12s%s\n", "From", "To", "Syms Read",
- "Shared Object Library");
+ printf_unfiltered("%-*s%-*s%-12s%s\n", addr_width, "From",
+ addr_width, "To", "Syms Read",
+ "Shared Object Library");
header_done++;
}
- printf ("%-12s", local_hex_string_custom (LM_ADDR (so), "08"));
- printf ("%-12s", local_hex_string_custom (so -> lmend, "08"));
- printf ("%-12s", so -> symbols_loaded ? "Yes" : "No");
- printf ("%s\n", so -> so_name);
+
+ printf_unfiltered ("%-*s", addr_width,
+ local_hex_string_custom ((unsigned long) LM_ADDR (so),
+ addr_fmt));
+ printf_unfiltered ("%-*s", addr_width,
+ local_hex_string_custom ((unsigned long) so -> lmend,
+ addr_fmt));
+ printf_unfiltered ("%-12s", so -> symbols_loaded ? "Yes" : "No");
+ printf_unfiltered ("%s\n", so -> so_name);
}
}
if (so_list_head == NULL)
{
- printf ("No shared libraries loaded at this time.\n");
+ printf_unfiltered ("No shared libraries loaded at this time.\n");
}
}
SYNOPSIS
- int solib_address (CORE_ADDR address)
+ char * solib_address (CORE_ADDR address)
DESCRIPTION
mapped in.
*/
-int
+char *
solib_address (address)
CORE_ADDR address;
{
{
if ((address >= (CORE_ADDR) LM_ADDR (so)) &&
(address < (CORE_ADDR) so -> lmend))
- {
- return (1);
- }
+ return (so->so_name);
}
}
return (0);
clear_solib()
{
struct so_list *next;
+ char *bfd_filename;
while (so_list_head)
{
if (so_list_head -> sections)
{
- free (so_list_head -> sections);
+ free ((PTR)so_list_head -> sections);
}
- if (so_list_head -> so_bfd)
+ if (so_list_head -> abfd)
{
- bfd_close (so_list_head -> so_bfd);
+ bfd_filename = bfd_get_filename (so_list_head -> abfd);
+ if (!bfd_close (so_list_head -> abfd))
+ warning ("cannot close \"%s\": %s",
+ bfd_filename, bfd_errmsg (bfd_get_error ()));
}
+ else
+ /* This happens for the executable on SVR4. */
+ bfd_filename = NULL;
+
next = so_list_head -> next;
- free(so_list_head);
+ if (bfd_filename)
+ free ((PTR)bfd_filename);
+ free ((PTR)so_list_head);
so_list_head = next;
}
debug_base = 0;
}
+static void
+do_clear_solib (dummy)
+ PTR dummy;
+{
+ solib_cleanup_queued = 0;
+ clear_solib ();
+}
+
+#ifdef SVR4_SHARED_LIBS
+
+/* 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;
+
+int
+in_svr4_dynsym_resolve_code (pc)
+ CORE_ADDR pc;
+{
+ return ((pc >= interp_text_sect_low && pc < interp_text_sect_high)
+ || (pc >= interp_plt_sect_low && pc < interp_plt_sect_high)
+ || in_plt_section (pc, NULL));
+}
+#endif
+
/*
LOCAL FUNCTION
*/
+#ifndef SVR4_SHARED_LIBS
+
static int
disable_break ()
{
int status = 1;
-#ifdef sun
-
- /* FIXME: maybe we should add the common symbols from the ldd_cp chain
- to the misc_function_vector ? */
+#ifndef SVR4_SHARED_LIBS
int in_debugger = 0;
- /* Set `in_debugger' to zero now. */
-
- write_memory (flag_addr, &in_debugger, sizeof (in_debugger));
-
/* Read the debugger structure from the inferior to retrieve the
address of the breakpoint and the original contents of the
breakpoint address. Remove the breakpoint by writing the original
contents back. */
- read_memory (debug_addr, &debug_copy, sizeof (debug_copy));
+ read_memory (debug_addr, (char *) &debug_copy, sizeof (debug_copy));
+
+ /* Set `in_debugger' to zero now. */
+
+ write_memory (flag_addr, (char *) &in_debugger, sizeof (in_debugger));
+
breakpoint_addr = (CORE_ADDR) debug_copy.ldd_bp_addr;
- write_memory (breakpoint_addr, &debug_copy.ldd_bp_inst,
+ write_memory (breakpoint_addr, (char *) &debug_copy.ldd_bp_inst,
sizeof (debug_copy.ldd_bp_inst));
-#else /* !sun */
+#else /* SVR4_SHARED_LIBS */
/* Note that breakpoint address and original contents are in our address
space, so we just need to write the original contents back. */
status = 0;
}
-#endif /* sun */
+#endif /* !SVR4_SHARED_LIBS */
/* For the SVR4 version, we always know the breakpoint address. For the
SunOS version we don't know it until the above code is executed.
return (status);
}
+#endif /* #ifdef SVR4_SHARED_LIBS */
+
/*
LOCAL FUNCTION
static int
enable_break ()
{
+ int success = 0;
- int j;
-
-#ifdef sun
+#ifndef SVR4_SHARED_LIBS
+ int j;
int in_debugger;
-
+
/* Get link_dynamic structure */
j = target_read_memory (debug_base, (char *) &dynamic_copy,
/* Write a value of 1 to this member. */
in_debugger = 1;
+ write_memory (flag_addr, (char *) &in_debugger, sizeof (in_debugger));
+ success = 1;
- write_memory (flag_addr, &in_debugger, sizeof (in_debugger));
+#else /* SVR4_SHARED_LIBS */
-#else /* !sun */
+#ifdef BKPT_AT_SYMBOL
-#ifdef BKPT_AT_MAIN
+ struct minimal_symbol *msymbol;
+ char **bkpt_namep;
+ asection *interp_sect;
- int i;
+ /* First, remove all the solib event breakpoints. Their addresses
+ may have changed since the last time we ran the program. */
+ remove_solib_event_breakpoints ();
- i = lookup_misc_func ("main");
- if (i >= 0 && misc_function_vector[i].address != 0)
- {
- breakpoint_addr = misc_function_vector[i].address;
- }
- else
- {
- return (0);
- }
+#ifdef SVR4_SHARED_LIBS
+ interp_text_sect_low = interp_text_sect_high = 0;
+ interp_plt_sect_low = interp_plt_sect_high = 0;
- if (target_insert_breakpoint (breakpoint_addr, shadow_contents) != 0)
+ /* Find the .interp section; 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)
{
- return (0);
- }
+ unsigned int interp_sect_size;
+ char *buf;
+ CORE_ADDR load_addr;
+ bfd *tmp_bfd;
+ CORE_ADDR sym_addr = 0;
+
+ /* 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);
+
+ /* Now we need to figure out where the dynamic linker was
+ loaded so that we can load its symbols and place a breakpoint
+ in the dynamic linker itself.
+
+ This address is stored on the stack. However, I've been unable
+ to find any magic formula to find it for Solaris (appears to
+ be trivial on Linux). Therefore, we have to try an alternate
+ mechanism to find the dynamic linker's base address. */
+ tmp_bfd = bfd_openr (buf, gnutarget);
+ 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;
+ }
-#else /* !BKPT_AT_MAIN */
+ /* We find the dynamic linker's base address by examining the
+ current pc (which point at the entry point for the dynamic
+ linker) and subtracting the offset of the entry point. */
+ load_addr = read_pc () - tmp_bfd->start_address;
- struct symtab_and_line sal;
+ /* Record the relocated start and end address of the dynamic linker
+ text and plt section for in_svr4_dynsym_resolve_code. */
+ interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
+ if (interp_sect)
+ {
+ 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);
+ }
+ interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt");
+ if (interp_sect)
+ {
+ 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);
+ }
- /* Read the debugger interface structure directly. */
+ /* Now try to set a breakpoint in the dynamic linker. */
+ for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
+ {
+ sym_addr = bfd_lookup_symbol (tmp_bfd, *bkpt_namep);
+ if (sym_addr != 0)
+ break;
+ }
- read_memory (debug_base, (char *) &debug_copy, sizeof (debug_copy));
+ /* We're done with the temporary bfd. */
+ bfd_close (tmp_bfd);
- /* Set breakpoint at the debugger interface stub routine that will
- be called just prior to each mapping change and again after the
- mapping change is complete. Set up the (nonexistent) handler to
- deal with hitting these breakpoints. (FIXME). */
+ if (sym_addr != 0)
+ {
+ create_solib_event_breakpoint (load_addr + sym_addr);
+ return 1;
+ }
- warning ("'%s': line %d: missing SVR4 support code", __FILE__, __LINE__);
+ /* 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.");
+ warning ("GDB will be unable to debug shared library initializers");
+ warning ("and track explicitly loaded dynamic code.");
+ }
+#endif
-#endif /* BKPT_AT_MAIN */
+ /* Scan through the list of symbols, trying to look up the symbol and
+ set a breakpoint there. Terminate loop when we/if we succeed. */
-#endif /* sun */
+ breakpoint_addr = 0;
+ 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))
+ {
+ create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol));
+ return 1;
+ }
+ }
- return (1);
+ /* Nothing good happened. */
+ success = 0;
+
+#endif /* BKPT_AT_SYMBOL */
+
+#endif /* !SVR4_SHARED_LIBS */
+
+ return (success);
}
/*
point, this function gets called via expansion of the macro
SOLIB_CREATE_INFERIOR_HOOK.
+ For SunOS executables, this first instruction is typically the
+ one at "_start", or a similar text label, regardless of whether
+ the executable is statically or dynamically linked. The runtime
+ startup code takes care of dynamically linking in any shared
+ libraries, once gdb allows the inferior to continue.
+
+ For SVR4 executables, this first instruction is either the first
+ instruction in the dynamic linker (for dynamically linked
+ executables) or the instruction at "start" for statically linked
+ executables. For dynamically linked executables, the system
+ first exec's /lib/libc.so.N, which contains the dynamic linker,
+ and starts it running. The dynamic linker maps in any needed
+ shared libraries, maps in the actual user executable, and then
+ jumps to "start" in the user executable.
+
For both SunOS shared libraries, and SVR4 shared libraries, we
can arrange to cooperate with the dynamic linker to discover the
names of shared libraries that are dynamically linked, and the
Also, what if child has exit()ed? Must exit loop somehow.
*/
-void
+void
solib_create_inferior_hook()
{
- CORE_ADDR debug_addr;
- int in_debugger;
- CORE_ADDR in_debugger_addr;
- CORE_ADDR breakpoint_addr;
- int i, j;
-
+ static int dyn_relocated;
+
+ /* If we are using the BKPT_AT_SYMBOL code, then we don't need the base
+ yet. In fact, in the case of a SunOS4 executable being run on
+ Solaris, we can't get it yet. find_solib will get it when it needs
+ it. */
+#if !(defined (SVR4_SHARED_LIBS) && defined (BKPT_AT_SYMBOL))
if ((debug_base = locate_base ()) == 0)
{
/* Can't find the symbol or the executable is statically linked. */
return;
}
+#endif
if (!enable_break ())
{
return;
}
- /* Now run the target. It will eventually hit the breakpoint, at
+ if (!dyn_relocated && exec_bfd->start_address != stop_pc)
+ {
+ /* We have to relocate the debug information. */
+ CORE_ADDR displacement = stop_pc - exec_bfd->start_address;
+ struct section_offsets *new_offsets;
+ int i;
+
+ new_offsets = alloca (symfile_objfile->num_sections
+ * sizeof (*new_offsets));
+
+ for (i = 0; i < symfile_objfile->num_sections; ++i)
+ ANOFFSET (new_offsets, i) =
+ ANOFFSET (symfile_objfile->section_offsets, i);
+
+ ANOFFSET (new_offsets, SECT_OFF_TEXT) += displacement;
+ ANOFFSET (new_offsets, SECT_OFF_DATA) += displacement;
+ ANOFFSET (new_offsets, SECT_OFF_BSS) += displacement;
+ ANOFFSET (new_offsets, SECT_OFF_RODATA) += displacement;
+
+ objfile_relocate (symfile_objfile, new_offsets);
+ breakpoint_re_set ();
+
+ /* Make sure this relocation is done only once. */
+ dyn_relocated = 1;
+ }
+
+#ifndef SVR4_SHARED_LIBS
+ /* Only SunOS needs the loop below, other systems should be using the
+ special shared library breakpoints and the shared library breakpoint
+ service routine.
+
+ 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. */
clear_proceed_status ();
stop_soon_quietly = 1;
- stop_signal = 0;
+ stop_signal = TARGET_SIGNAL_0;
do
{
- target_resume (0, stop_signal);
+ target_resume (-1, 0, stop_signal);
wait_for_inferior ();
}
- while (stop_signal != SIGTRAP);
+ while (stop_signal != TARGET_SIGNAL_TRAP);
stop_soon_quietly = 0;
/* We are now either at the "mapping complete" breakpoint (or somewhere
warning ("shared library handler failed to disable breakpoint");
}
- solib_add ((char *) 0, 0, (struct target_ops *) 0);
+ if (auto_solib_add)
+ solib_add ((char *) 0, 0, (struct target_ops *) 0);
+#endif
}
/*
-GLOBAL FUNCTION
+LOCAL FUNCTION
+
+ special_symbol_handling -- additional shared library symbol handling
+
+SYNOPSIS
+
+ void special_symbol_handling (struct so_list *so)
+
+DESCRIPTION
+
+ Once the symbols from a shared object have been loaded in the usual
+ way, we are called to do any system specific symbol handling that
+ is needed.
+
+ For SunOS4, this consists of grunging around in the dynamic
+ linkers structures to find symbol definitions for "common" symbols
+ and adding them to the minimal symbol table for the runtime common
+ objfile.
+
+*/
+
+static void
+special_symbol_handling (so)
+struct so_list *so;
+{
+#ifndef SVR4_SHARED_LIBS
+ int j;
+
+ if (debug_addr == 0)
+ {
+ /* Get link_dynamic structure */
+
+ j = target_read_memory (debug_base, (char *) &dynamic_copy,
+ sizeof (dynamic_copy));
+ if (j)
+ {
+ /* unreadable */
+ return;
+ }
+
+ /* Calc address of debugger interface structure */
+ /* FIXME, this needs work for cross-debugging of core files
+ (byteorder, size, alignment, etc). */
+
+ debug_addr = (CORE_ADDR) dynamic_copy.ldd;
+ }
+
+ /* Read the debugger structure from the inferior, just to make sure
+ we have a current copy. */
+
+ j = target_read_memory (debug_addr, (char *) &debug_copy,
+ sizeof (debug_copy));
+ if (j)
+ return; /* unreadable */
+
+ /* Get common symbol definitions for the loaded object. */
+
+ if (debug_copy.ldd_cp)
+ {
+ solib_add_common_symbols (debug_copy.ldd_cp);
+ }
+
+#endif /* !SVR4_SHARED_LIBS */
+}
+
+
+/*
+
+LOCAL FUNCTION
sharedlibrary_command -- handle command to explicitly add library
SYNOPSIS
- void sharedlibrary_command (char *args, int from_tty)
+ static void sharedlibrary_command (char *args, int from_tty)
DESCRIPTION
*/
-void
+static void
sharedlibrary_command (args, from_tty)
char *args;
int from_tty;
solib_add (args, from_tty, (struct target_ops *) 0);
}
+#endif /* HAVE_LINK_H */
+
void
_initialize_solib()
{
-
+#ifdef HAVE_LINK_H
+
add_com ("sharedlibrary", class_files, sharedlibrary_command,
"Load shared object library symbols for files matching REGEXP.");
add_info ("sharedlibrary", info_sharedlibrary_command,
"Status of loaded shared object libraries.");
+
+ add_show_from_set
+ (add_set_cmd ("auto-solib-add", class_support, var_zinteger,
+ (char *) &auto_solib_add,
+ "Set autoloading of shared library symbols.\n\
+If nonzero, symbols from all shared object libraries will be loaded\n\
+automatically when the inferior begins execution or when the dynamic linker\n\
+informs gdb that a new library has been loaded. Otherwise, symbols\n\
+must be loaded manually, using `sharedlibrary'.",
+ &setlist),
+ &showlist);
+
+ add_show_from_set
+ (add_set_cmd ("solib-absolute-prefix", class_support, var_filename,
+ (char *) &solib_absolute_prefix,
+ "Set prefix for loading absolute shared library symbol files.\n\
+For other (relative) files, you can add values using `set solib-search-path'.",
+ &setlist),
+ &showlist);
+ add_show_from_set
+ (add_set_cmd ("solib-search-path", class_support, var_string,
+ (char *) &solib_search_path,
+ "Set the search path for loading non-absolute shared library symbol files.\n\
+This takes precedence over the environment variables PATH and LD_LIBRARY_PATH.",
+ &setlist),
+ &showlist);
+
+#endif /* HAVE_LINK_H */
}
projects / deliverable / binutils-gdb.git / blobdiff