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Diffstat (limited to 'gdb/solib.c')
| -rw-r--r-- | gdb/solib.c | 1888 |
1 files changed, 1888 insertions, 0 deletions
diff --git a/gdb/solib.c b/gdb/solib.c new file mode 100644 index 00000000000..6d6fd4a3a84 --- /dev/null +++ b/gdb/solib.c @@ -0,0 +1,1888 @@ +/* Handle SunOS and SVR4 shared libraries for GDB, the GNU Debugger. + Copyright 1990, 91, 92, 93, 94, 95, 96, 98, 1999 + 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 +(at your option) any later version. + +This program is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received 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. */ + + +#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 "gdb_string.h" +#include <sys/param.h> +#include <fcntl.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 "symtab.h" +#include "bfd.h" +#include "symfile.h" +#include "objfiles.h" +#include "gdbcore.h" +#include "command.h" +#include "target.h" +#include "frame.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 + +#define BKPT_AT_SYMBOL 1 + +#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 + +/* Symbols which are used to locate the base of the link map structures. */ + +#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 */ + +#ifndef SVR4_SHARED_LIBS + +#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 /* SVR4_SHARED_LIBS */ + +#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; +char shadow_contents[BREAKPOINT_MAX]; /* Stash old bkpt addr contents */ + +#endif /* !SVR4_SHARED_LIBS */ + +struct so_list { + struct so_list *next; /* next structure in linked list */ + struct link_map lm; /* copy of link map from inferior */ + struct link_map *lmaddr; /* addr in inferior lm was read from */ + CORE_ADDR lmend; /* upper addr bound of mapped object */ + 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? */ + 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 ((PTR)); + +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 int solib_map_sections PARAMS ((PTR)); + +#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 + +void _initialize_solib PARAMS ((void)); + +/* 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; + +/* + +LOCAL FUNCTION + + solib_map_sections -- open bfd and build sections for shared lib + +SYNOPSIS + + static int solib_map_sections (struct so_list *so) + +DESCRIPTION + + Given a pointer to one of the shared objects in our list + of mapped objects, use the recorded name to open a bfd + descriptor for the object, build a section table, and then + relocate all the section addresses by the base address at + which the shared object was mapped. + +FIXMES + + In most (all?) cases the shared object file name recorded in the + dynamic linkage tables will be a fully qualified pathname. For + cases where it isn't, do we really mimic the systems search + mechanism correctly in the below code (particularly the tilde + expansion stuff?). + */ + +static int +solib_map_sections (arg) + PTR arg; +{ + struct so_list *so = (struct so_list *) arg; /* catch_errors bogon */ + char *filename; + char *scratch_pathname; + int scratch_chan; + struct section_table *p; + struct cleanup *old_chain; + bfd *abfd; + + filename = tilde_expand (so -> so_name); + + 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 (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. */ + + 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_get_error ())); + } + /* 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_get_error ())); + } + if (build_section_table (abfd, &so -> sections, &so -> sections_end)) + { + error ("Can't find the file sections in `%s': %s", + bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ())); + } + + for (p = so -> sections; p < so -> sections_end; p++) + { + /* Relocate the section binding addresses as recorded in the shared + object's file by the base address to which the object was actually + mapped. */ + 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); + + return (1); +} + +#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 ((make_cleanup_func) 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 + + bfd_lookup_symbol -- lookup the value for a specific symbol + +SYNOPSIS + + 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. + + Note that 0 is specifically allowed as an error return (no + such symbol). +*/ + +static CORE_ADDR +bfd_lookup_symbol (abfd, symname) + bfd *abfd; + char *symname; +{ + unsigned int storage_needed; + asymbol *sym; + asymbol **symbol_table; + unsigned int number_of_symbols; + unsigned int i; + struct cleanup *back_to; + CORE_ADDR symaddr = 0; + + storage_needed = bfd_get_symtab_upper_bound (abfd); + + if (storage_needed > 0) + { + 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 (STREQ (sym -> name, symname)) + { + /* Bfd symbols are section relative. */ + symaddr = sym -> value + sym -> section -> vma; + break; + } + } + do_cleanups (back_to); + } + 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). +*/ + +static char *debug_base_symbols[] = { + "r_debug", /* Solaris 2.3 */ + "_r_debug", /* Solaris 2.1, 2.2 */ + NULL +}; + +static int +look_for_base PARAMS ((int, CORE_ADDR)); + +/* + +LOCAL FUNCTION + + look_for_base -- examine file for each mapped address segment + +SYNOPSYS + + static int look_for_base (int fd, CORE_ADDR baseaddr) + +DESCRIPTION + + 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. + + 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 int +look_for_base (fd, baseaddr) + int fd; + CORE_ADDR baseaddr; +{ + bfd *interp_bfd; + CORE_ADDR address = 0; + char **symbolp; + + /* 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. */ + + if (fd == -1 + || (exec_bfd != NULL + && fdmatch (fileno ((FILE *)(exec_bfd -> iostream)), fd))) + { + return (0); + } + + /* 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. */ + + if ((interp_bfd = bfd_fdopenr ("unnamed", gnutarget, fd)) == NULL) + { + return (0); + } + if (!bfd_check_format (interp_bfd, bfd_object)) + { + /* FIXME-leak: on failure, might not free all memory associated with + interp_bfd. */ + bfd_close (interp_bfd); + return (0); + } + + /* 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++) + { + address = bfd_lookup_symbol (interp_bfd, *symbolp); + if (address != 0) + { + break; + } + } + if (address == 0) + { + /* FIXME-leak: on failure, might not free all memory associated with + interp_bfd. */ + bfd_close (interp_bfd); + return (0); + } + + /* 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) + { + address += baseaddr; + } + 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)) + { + 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 + } +#else /* ELF64 */ + 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; + } + } +#endif + + /* DT_DEBUG entry not found. */ + return 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++) + { + msymbol = lookup_minimal_symbol (*symbolp, NULL, symfile_objfile); + if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0)) + { + address = SYMBOL_VALUE_ADDRESS (msymbol); + return (address); + } + } + return (0); + +#else /* SVR4_SHARED_LIBS */ + + /* 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) + { + 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); + +#endif /* !SVR4_SHARED_LIBS */ + +} + +/* + +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; + +#ifndef SVR4_SHARED_LIBS + + 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, (char *) &ld_2_copy, + sizeof (struct link_dynamic_2)); + lm = ld_2_copy.ld_loaded; + } + +#else /* SVR4_SHARED_LIBS */ + + 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 /* !SVR4_SHARED_LIBS */ + + return (lm); +} + +/* + +LOCAL FUNCTION + + find_solib -- step through list of shared objects + +SYNOPSIS + + struct so_list *find_solib (struct so_list *so_list_ptr) + +DESCRIPTION + + This module contains the routine which finds the names of any + loaded "images" in the current process. The argument in must be + NULL on the first call, and then the returned value must be passed + in on subsequent calls. This provides the capability to "step" down + the list of loaded objects. On the last object, a NULL value is + returned. + + The arg and return value are "struct link_map" pointers, as defined + in <link.h>. + */ + +static struct so_list * +find_solib (so_list_ptr) + struct so_list *so_list_ptr; /* Last lm or NULL for first one */ +{ + struct so_list *so_list_next = NULL; + struct link_map *lm = NULL; + struct so_list *new; + + if (so_list_ptr == NULL) + { + /* We are setting up for a new scan through the loaded images. */ + if ((so_list_next = so_list_head) == NULL) + { + /* 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) + { + /* Read the base structure in and find the address of the first + link map list member. */ + lm = first_link_map_member (); + } + } + } + else + { + /* We have been called before, and are in the process of walking + the shared library list. Advance to the next shared object. */ + if ((lm = LM_NEXT (so_list_ptr)) == NULL) + { + /* We have hit the end of the list, so check to see if any were + added, but be quiet if we can't read from the target any more. */ + int status = target_read_memory ((CORE_ADDR) so_list_ptr -> lmaddr, + (char *) &(so_list_ptr -> lm), + sizeof (struct link_map)); + if (status == 0) + { + lm = LM_NEXT (so_list_ptr); + } + else + { + lm = NULL; + } + } + so_list_next = so_list_ptr -> next; + } + if ((so_list_next == NULL) && (lm != NULL)) + { + /* 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)); + 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. */ + if (so_list_ptr != NULL) + { + so_list_ptr -> next = new; + } + else + { + so_list_head = new; + + if (! solib_cleanup_queued) + { + make_run_cleanup (do_clear_solib, NULL); + solib_cleanup_queued = 1; + } + + } + so_list_next = new; + 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)) + { + int errcode; + char *buffer; + target_read_string ((CORE_ADDR) LM_NAME (new), &buffer, + MAX_PATH_SIZE - 1, &errcode); + if (errcode != 0) + { + warning ("find_solib: Can't read pathname for load map: %s\n", + safe_strerror (errcode)); + return (so_list_next); + } + strncpy (new -> so_name, buffer, MAX_PATH_SIZE - 1); + new -> so_name[MAX_PATH_SIZE - 1] = '\0'; + free (buffer); + catch_errors (solib_map_sections, new, + "Error while mapping shared library sections:\n", + RETURN_MASK_ALL); + } + } + return (so_list_next); +} + +/* A small stub to get us past the arg-passing pinhole of catch_errors. */ + +static int +symbol_add_stub (arg) + PTR 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 if (so -> abfd != NULL) + { + 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); + } + + 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, 0, 1); + 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 + + solib_add -- add a shared library file to the symtab and section list + +SYNOPSIS + + void solib_add (char *arg_string, int from_tty, + struct target_ops *target) + +DESCRIPTION + +*/ + +void +solib_add (arg_string, from_tty, target) + char *arg_string; + int from_tty; + 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; + + if ((re_err = re_comp (arg_string ? arg_string : ".")) != NULL) + { + error ("Invalid regexp: %s", re_err); + } + + /* Add the shared library sections to the section table of the + specified target, if any. */ + if (target) + { + /* Count how many new section_table entries there are. */ + so = NULL; + count = 0; + while ((so = find_solib (so)) != NULL) + { + 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 -> to_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 -> to_sections = (struct section_table *) + xmalloc ((sizeof (struct section_table)) * count); + } + 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; + 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, 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); +} + +/* + +LOCAL FUNCTION + + info_sharedlibrary_command -- code for "info sharedlibrary" + +SYNOPSIS + + static void info_sharedlibrary_command () + +DESCRIPTION + + Walk through the shared library list and print information + about each attached library. +*/ + +static void +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_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_unfiltered("%-*s%-*s%-12s%s\n", addr_width, "From", + addr_width, "To", "Syms Read", + "Shared Object Library"); + header_done++; + } + + 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_unfiltered ("No shared libraries loaded at this time.\n"); + } +} + +/* + +GLOBAL FUNCTION + + solib_address -- check to see if an address is in a shared lib + +SYNOPSIS + + char * solib_address (CORE_ADDR address) + +DESCRIPTION + + Provides a hook for other gdb routines to discover whether or + not a particular address is within the mapped address space of + a shared library. Any address between the base mapping address + and the first address beyond the end of the last mapping, is + considered to be within the shared library address space, for + our purposes. + + For example, this routine is called at one point to disable + breakpoints which are in shared libraries that are not currently + mapped in. + */ + +char * +solib_address (address) + CORE_ADDR address; +{ + register struct so_list *so = 0; /* link map state variable */ + + while ((so = find_solib (so)) != NULL) + { + if (so -> so_name[0]) + { + if ((address >= (CORE_ADDR) LM_ADDR (so)) && + (address < (CORE_ADDR) so -> lmend)) + return (so->so_name); + } + } + return (0); +} + +/* Called by free_all_symtabs */ + +void +clear_solib() +{ + struct so_list *next; + char *bfd_filename; + + while (so_list_head) + { + if (so_list_head -> sections) + { + free ((PTR)so_list_head -> sections); + } + if (so_list_head -> abfd) + { + 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; + 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 + + disable_break -- remove the "mapping changed" breakpoint + +SYNOPSIS + + static int disable_break () + +DESCRIPTION + + Removes the breakpoint that gets hit when the dynamic linker + completes a mapping change. + +*/ + +#ifndef SVR4_SHARED_LIBS + +static int +disable_break () +{ + int status = 1; + +#ifndef SVR4_SHARED_LIBS + + int in_debugger = 0; + + /* 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, (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, (char *) &debug_copy.ldd_bp_inst, + sizeof (debug_copy.ldd_bp_inst)); + +#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. */ + + if (memory_remove_breakpoint (breakpoint_addr, shadow_contents) != 0) + { + status = 0; + } + +#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. + Grumble if we are stopped anywhere besides the breakpoint address. */ + + if (stop_pc != breakpoint_addr) + { + warning ("stopped at unknown breakpoint while handling shared libraries"); + } + + return (status); +} + +#endif /* #ifdef SVR4_SHARED_LIBS */ + +/* + +LOCAL FUNCTION + + enable_break -- arrange for dynamic linker to hit breakpoint + +SYNOPSIS + + int enable_break (void) + +DESCRIPTION + + Both the SunOS and the SVR4 dynamic linkers have, as part of their + debugger interface, support for arranging for the inferior to hit + a breakpoint after mapping in the shared libraries. This function + enables that breakpoint. + + For SunOS, there is a special flag location (in_debugger) which we + set to 1. When the dynamic linker sees this flag set, it will set + a breakpoint at a location known only to itself, after saving the + original contents of that place and the breakpoint address itself, + in it's own internal structures. When we resume the inferior, it + will eventually take a SIGTRAP when it runs into the breakpoint. + We handle this (in a different place) by restoring the contents of + the breakpointed location (which is only known after it stops), + chasing around to locate the shared libraries that have been + loaded, then resuming. + + For SVR4, the debugger interface structure contains a member (r_brk) + which is statically initialized at the time the shared library is + built, to the offset of a function (_r_debug_state) which is guaran- + teed to be called once before mapping in a library, and again when + the mapping is complete. At the time we are examining this member, + it contains only the unrelocated offset of the function, so we have + to do our own relocation. Later, when the dynamic linker actually + runs, it relocates r_brk to be the actual address of _r_debug_state(). + + The debugger interface structure also contains an enumeration which + is set to either RT_ADD or RT_DELETE prior to changing the mapping, + depending upon whether or not the library is being mapped or unmapped, + and then set to RT_CONSISTENT after the library is mapped/unmapped. +*/ + +static int +enable_break () +{ + int success = 0; + +#ifndef SVR4_SHARED_LIBS + + int j; + int in_debugger; + + /* Get link_dynamic structure */ + + j = target_read_memory (debug_base, (char *) &dynamic_copy, + sizeof (dynamic_copy)); + if (j) + { + /* unreadable */ + return (0); + } + + /* Calc address of debugger interface structure */ + + debug_addr = (CORE_ADDR) dynamic_copy.ldd; + + /* Calc address of `in_debugger' member of debugger interface structure */ + + flag_addr = debug_addr + (CORE_ADDR) ((char *) &debug_copy.ldd_in_debugger - + (char *) &debug_copy); + + /* Write a value of 1 to this member. */ + + in_debugger = 1; + write_memory (flag_addr, (char *) &in_debugger, sizeof (in_debugger)); + success = 1; + +#else /* SVR4_SHARED_LIBS */ + +#ifdef BKPT_AT_SYMBOL + + struct minimal_symbol *msymbol; + char **bkpt_namep; + asection *interp_sect; + + /* First, remove all the solib event breakpoints. Their addresses + may have changed since the last time we ran the program. */ + remove_solib_event_breakpoints (); + +#ifdef SVR4_SHARED_LIBS + interp_text_sect_low = interp_text_sect_high = 0; + interp_plt_sect_low = interp_plt_sect_high = 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) + { + 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 GNU/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; + } + + /* 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; + + /* 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); + } + + /* 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; + } + + /* We're done with the temporary bfd. */ + bfd_close (tmp_bfd); + + if (sym_addr != 0) + { + create_solib_event_breakpoint (load_addr + sym_addr); + 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."); + } +#endif + + /* Scan through the list 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++) + { + 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; + } + } + + /* Nothing good happened. */ + success = 0; + +#endif /* BKPT_AT_SYMBOL */ + +#endif /* !SVR4_SHARED_LIBS */ + + return (success); +} + +/* + +GLOBAL FUNCTION + + solib_create_inferior_hook -- shared library startup support + +SYNOPSIS + + void solib_create_inferior_hook() + +DESCRIPTION + + When gdb starts up the inferior, it nurses it along (through the + shell) until it is ready to execute it's first instruction. At this + 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 + base addresses to which they are linked. + + This function is responsible for discovering those names and + addresses, and saving sufficient information about them to allow + their symbols to be read at a later time. + +FIXME + + Between enable_break() and disable_break(), this code does not + properly handle hitting breakpoints which the user might have + set in the startup code or in the dynamic linker itself. Proper + handling will probably have to wait until the implementation is + changed to use the "breakpoint handler function" method. + + Also, what if child has exit()ed? Must exit loop somehow. + */ + +void +solib_create_inferior_hook() +{ + /* 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 ()) + { + warning ("shared library handler failed to enable breakpoint"); + return; + } + +#if !defined(SVR4_SHARED_LIBS) || defined(_SCO_DS) + /* SCO and SunOS need 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 = TARGET_SIGNAL_0; + do + { + target_resume (-1, 0, stop_signal); + wait_for_inferior (); + } + while (stop_signal != TARGET_SIGNAL_TRAP); + stop_soon_quietly = 0; + +#if !defined(_SCO_DS) + /* We are now either at the "mapping complete" breakpoint (or somewhere + else, a condition we aren't prepared to deal with anyway), so adjust + the PC as necessary after a breakpoint, disable the breakpoint, and + add any shared libraries that were mapped in. */ + + if (DECR_PC_AFTER_BREAK) + { + stop_pc -= DECR_PC_AFTER_BREAK; + write_register (PC_REGNUM, stop_pc); + } + + if (!disable_break ()) + { + warning ("shared library handler failed to disable breakpoint"); + } + + if (auto_solib_add) + solib_add ((char *) 0, 0, (struct target_ops *) 0); +#endif /* ! _SCO_DS */ +#endif +} + +/* + +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 + + static void sharedlibrary_command (char *args, int from_tty) + +DESCRIPTION + +*/ + +static void +sharedlibrary_command (args, from_tty) +char *args; +int from_tty; +{ + dont_repeat (); + 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 */ +} |