diff options
Diffstat (limited to 'gdb/solib-pa64.c')
| -rw-r--r-- | gdb/solib-pa64.c | 653 |
1 files changed, 653 insertions, 0 deletions
diff --git a/gdb/solib-pa64.c b/gdb/solib-pa64.c new file mode 100644 index 0000000..9f54104 --- /dev/null +++ b/gdb/solib-pa64.c @@ -0,0 +1,653 @@ +/* Handle PA64 shared libraries for GDB, the GNU Debugger. + + Copyright 2004 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. + + HP in their infinite stupidity choose not to use standard ELF dynamic + linker interfaces. They also choose not to make their ELF dymamic + linker interfaces compatible with the SOM dynamic linker. The + net result is we can not use either of the existing somsolib.c or + solib.c. What a crock. + + Even more disgusting. This file depends on functions provided only + in certain PA64 libraries. Thus this file is supposed to only be + used native. When will HP ever learn that they need to provide the + same functionality in all their libraries! */ + +#include "defs.h" +#include <dlfcn.h> +#include <elf.h> +#include <elf_hp.h> +#include "symtab.h" +#include "bfd.h" +#include "symfile.h" +#include "objfiles.h" +#include "gdbcore.h" +#include "target.h" +#include "inferior.h" + +#include "hppa-tdep.h" +#include "solist.h" +#include "solib-pa64.h" + +#undef SOLIB_PA64_DBG + +/* If we are building for a SOM-only target, then we don't need this. */ +#ifndef PA_SOM_ONLY + +struct lm_info { + struct load_module_desc desc; + CORE_ADDR desc_addr; +}; + +/* When adding fields, be sure to clear them in _initialize_pa64_solib. */ +typedef struct + { + CORE_ADDR dld_flags_addr; + LONGEST dld_flags; + struct bfd_section *dyninfo_sect; + int have_read_dld_descriptor; + int is_valid; + CORE_ADDR load_map; + CORE_ADDR load_map_addr; + struct load_module_desc dld_desc; + } +dld_cache_t; + +static dld_cache_t dld_cache; + +static int +read_dynamic_info (asection *dyninfo_sect, dld_cache_t *dld_cache_p); + +static void +pa64_relocate_section_addresses (struct so_list *so, + struct section_table *sec) +{ +} + +static void +pa64_free_so (struct so_list *so) +{ + xfree (so->lm_info); +} + +static void +pa64_clear_solib (void) +{ +} + +/* Wrapper for target_read_memory for dlgetmodinfo. */ + +static void * +pa64_target_read_memory (void *buffer, CORE_ADDR ptr, size_t bufsiz, int ident) +{ + if (target_read_memory (ptr, buffer, bufsiz) != 0) + return 0; + return buffer; +} + +/* Read the dynamic linker's internal shared library descriptor. + + This must happen after dld starts running, so we can't do it in + read_dynamic_info. Record the fact that we have loaded the + descriptor. If the library is archive bound, then return zero, else + return nonzero. */ + +static int +read_dld_descriptor (void) +{ + char *dll_path; + asection *dyninfo_sect; + + /* If necessary call read_dynamic_info to extract the contents of the + .dynamic section from the shared library. */ + if (!dld_cache.is_valid) + { + if (symfile_objfile == NULL) + error ("No object file symbols."); + + dyninfo_sect = bfd_get_section_by_name (symfile_objfile->obfd, + ".dynamic"); + if (!dyninfo_sect) + { + return 0; + } + + if (!read_dynamic_info (dyninfo_sect, &dld_cache)) + error ("Unable to read in .dynamic section information."); + } + + /* Read the load map pointer. */ + if (target_read_memory (dld_cache.load_map_addr, + (char *) &dld_cache.load_map, + sizeof (dld_cache.load_map)) + != 0) + { + error ("Error while reading in load map pointer."); + } + + /* Read in the dld load module descriptor */ + if (dlgetmodinfo (-1, + &dld_cache.dld_desc, + sizeof (dld_cache.dld_desc), + pa64_target_read_memory, + 0, + dld_cache.load_map) + == 0) + { + error ("Error trying to get information about dynamic linker."); + } + + /* Indicate that we have loaded the dld descriptor. */ + dld_cache.have_read_dld_descriptor = 1; + + return 1; +} + + +/* Read the .dynamic section and extract the information of interest, + which is stored in dld_cache. The routine elf_locate_base in solib.c + was used as a model for this. */ + +static int +read_dynamic_info (asection *dyninfo_sect, dld_cache_t *dld_cache_p) +{ + char *buf; + char *bufend; + CORE_ADDR dyninfo_addr; + int dyninfo_sect_size; + CORE_ADDR entry_addr; + + /* Read in .dynamic section, silently ignore errors. */ + dyninfo_addr = bfd_section_vma (symfile_objfile->obfd, dyninfo_sect); + 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; + + /* Scan the .dynamic section and record the items of interest. + In particular, DT_HP_DLD_FLAGS */ + for (bufend = buf + dyninfo_sect_size, entry_addr = dyninfo_addr; + buf < bufend; + buf += sizeof (Elf64_Dyn), entry_addr += sizeof (Elf64_Dyn)) + { + Elf64_Dyn *x_dynp = (Elf64_Dyn*)buf; + Elf64_Sxword dyn_tag; + CORE_ADDR dyn_ptr; + char *pbuf; + + pbuf = alloca (TARGET_PTR_BIT / HOST_CHAR_BIT); + dyn_tag = bfd_h_get_64 (symfile_objfile->obfd, + (bfd_byte*) &x_dynp->d_tag); + + /* We can't use a switch here because dyn_tag is 64 bits and HP's + lame comiler does not handle 64bit items in switch statements. */ + if (dyn_tag == DT_NULL) + break; + else if (dyn_tag == DT_HP_DLD_FLAGS) + { + /* Set dld_flags_addr and dld_flags in *dld_cache_p */ + dld_cache_p->dld_flags_addr = entry_addr + offsetof(Elf64_Dyn, d_un); + if (target_read_memory (dld_cache_p->dld_flags_addr, + (char*) &dld_cache_p->dld_flags, + sizeof (dld_cache_p->dld_flags)) + != 0) + { + error ("Error while reading in .dynamic section of the program."); + } + } + else if (dyn_tag == DT_HP_LOAD_MAP) + { + /* Dld will place the address of the load map at load_map_addr + after it starts running. */ + if (target_read_memory (entry_addr + offsetof(Elf64_Dyn, + d_un.d_ptr), + (char*) &dld_cache_p->load_map_addr, + sizeof (dld_cache_p->load_map_addr)) + != 0) + { + error ("Error while reading in .dynamic section of the program."); + } + } + else + { + /* tag is not of interest */ + } + } + + /* Record other information and set is_valid to 1. */ + dld_cache_p->dyninfo_sect = dyninfo_sect; + + /* Verify that we read in required info. These fields are re-set to zero + in pa64_solib_restart. */ + + if (dld_cache_p->dld_flags_addr != 0 && dld_cache_p->load_map_addr != 0) + dld_cache_p->is_valid = 1; + else + return 0; + + return 1; +} + +/* + bfd_lookup_symbol -- lookup the value for a specific symbol + + 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 (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 (xfree, 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) + { + /* Bfd symbols are section relative. */ + symaddr = sym->value + sym->section->vma; + break; + } + } + do_cleanups (back_to); + } + return (symaddr); +} + + +/* This hook gets called just before the first instruction in the + inferior process is executed. + + This is our opportunity to set magic flags in the inferior so + that GDB can be notified when a shared library is mapped in and + to tell the dynamic linker that a private copy of the library is + needed (so GDB can set breakpoints in the library). + + We need to set two flag bits in this routine. + + DT_HP_DEBUG_PRIVATE to indicate that shared libraries should be + mapped private. + + DT_HP_DEBUG_CALLBACK to indicate that we want the dynamic linker to + call the breakpoint routine for significant events. */ + +static void +pa64_solib_create_inferior_hook (void) +{ + struct minimal_symbol *msymbol; + unsigned int dld_flags, status; + asection *shlib_info, *interp_sect; + char buf[4]; + struct objfile *objfile; + CORE_ADDR anaddr; + + /* First, remove all the solib event breakpoints. Their addresses + may have changed since the last time we ran the program. */ + remove_solib_event_breakpoints (); + + if (symfile_objfile == NULL) + return; + + /* First see if the objfile was dynamically linked. */ + shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, ".dynamic"); + if (!shlib_info) + return; + + /* It's got a .dynamic section, make sure it's not empty. */ + if (bfd_section_size (symfile_objfile->obfd, shlib_info) == 0) + return; + + /* Read in the .dynamic section. */ + if (! read_dynamic_info (shlib_info, &dld_cache)) + error ("Unable to read the .dynamic section."); + + /* Turn on the flags we care about. */ + dld_cache.dld_flags |= DT_HP_DEBUG_PRIVATE; + dld_cache.dld_flags |= DT_HP_DEBUG_CALLBACK; + status = target_write_memory (dld_cache.dld_flags_addr, + (char *) &dld_cache.dld_flags, + sizeof (dld_cache.dld_flags)); + if (status != 0) + error ("Unable to modify dynamic linker flags."); + + /* Now we have to create a shared library breakpoint in the dynamic + linker. This can be somewhat tricky since the symbol is inside + the dynamic linker (for which we do not have symbols or a base + load address! Luckily I wrote this code for solib.c years ago. */ + 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) + return; + + /* 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); + return; + } + + /* 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. + + Also note the breakpoint is the second instruction in the + routine. */ + load_addr = read_pc () - tmp_bfd->start_address; + sym_addr = bfd_lookup_symbol (tmp_bfd, "__dld_break"); + sym_addr = load_addr + sym_addr + 4; + + /* Create the shared library breakpoint. */ + { + struct breakpoint *b + = create_solib_event_breakpoint (sym_addr); + + /* The breakpoint is actually hard-coded into the dynamic linker, + so we don't need to actually insert a breakpoint instruction + there. In fact, the dynamic linker's code is immutable, even to + ttrace, so we shouldn't even try to do that. For cases like + this, we have "permanent" breakpoints. */ + make_breakpoint_permanent (b); + } + + /* We're done with the temporary bfd. */ + bfd_close (tmp_bfd); + } +} + +static void +pa64_special_symbol_handling (void) +{ +} + +static struct so_list * +pa64_current_sos (void) +{ + struct so_list *head = 0; + struct so_list **link_ptr = &head; + int dll_index; + + /* Read in the load map pointer if we have not done so already. */ + if (! dld_cache.have_read_dld_descriptor) + if (! read_dld_descriptor ()) + return NULL; + + /* If the libraries were not mapped private, warn the user. */ + if ((dld_cache.dld_flags & DT_HP_DEBUG_PRIVATE) == 0) + warning ("The shared libraries were not privately mapped; setting a\n" + "breakpoint in a shared library will not work until you rerun " + "the program.\n"); + + for (dll_index = 1; ; dll_index++) + { + struct load_module_desc dll_desc; + char *dll_path; + struct so_list *new; + struct cleanup *old_chain; + + /* Read in the load module descriptor. */ + if (dlgetmodinfo (dll_index, &dll_desc, sizeof (dll_desc), + pa64_target_read_memory, 0, dld_cache.load_map) + == 0) + break; + + /* Get the name of the shared library. */ + dll_path = (char *)dlgetname (&dll_desc, sizeof (dll_desc), + pa64_target_read_memory, + 0, dld_cache.load_map); + + if (dll_path == NULL) + dll_path = ""; + + new = (struct so_list *) xmalloc (sizeof (struct so_list)); + memset (new, 0, sizeof (struct so_list)); + new->lm_info = (struct lm_info *) xmalloc (sizeof (struct lm_info)); + memset (new->lm_info, 0, sizeof (struct lm_info)); + + strncpy (new->so_name, dll_path, SO_NAME_MAX_PATH_SIZE - 1); + new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; + strcpy (new->so_original_name, new->so_name); + + memcpy (&new->lm_info->desc, &dll_desc, sizeof (dll_desc)); + +#ifdef SOLIB_PA64_DBG + { + struct load_module_desc *d = &new->lm_info->desc; + printf ("\n+ library \"%s\" is described at index %d\n", new->so_name, + dll_index); + printf (" text_base = 0x%llx\n", d->text_base); + printf (" text_size = 0x%llx\n", d->text_size); + printf (" data_base = 0x%llx\n", d->data_base); + printf (" data_size = 0x%llx\n", d->data_size); + printf (" unwind_base = 0x%llx\n", d->unwind_base); + printf (" linkage_ptr = 0x%llx\n", d->linkage_ptr); + printf (" phdr_base = 0x%llx\n", d->phdr_base); + printf (" tls_size = 0x%llx\n", d->tls_size); + printf (" tls_start_addr = 0x%llx\n", d->tls_start_addr); + printf (" unwind_size = 0x%llx\n", d->unwind_size); + printf (" tls_index = 0x%llx\n", d->tls_index); + } +#endif + + /* Link the new object onto the list. */ + new->next = NULL; + *link_ptr = new; + link_ptr = &new->next; + } + + return head; +} + +static int +pa64_open_symbol_file_object (void *from_ttyp) +{ + int from_tty = *(int *)from_ttyp; + char buf[4]; + struct load_module_desc dll_desc; + char *dll_path; + + if (symfile_objfile) + if (!query ("Attempt to reload symbols from process? ")) + return 0; + + /* Read in the load map pointer if we have not done so already. */ + if (! dld_cache.have_read_dld_descriptor) + if (! read_dld_descriptor ()) + return 0; + + /* Read in the load module descriptor. */ + if (dlgetmodinfo (0, &dll_desc, sizeof (dll_desc), + pa64_target_read_memory, 0, dld_cache.load_map) == 0) + return 0; + + /* Get the name of the shared library. */ + dll_path = (char *)dlgetname (&dll_desc, sizeof (dll_desc), + pa64_target_read_memory, + 0, dld_cache.load_map); + + /* Have a pathname: read the symbol file. */ + symbol_file_add_main (dll_path, from_tty); + + return 1; +} + +/* Return nonzero if PC is an address inside the dynamic linker. */ +static int +pa64_in_dynsym_resolve_code (CORE_ADDR pc) +{ + asection *shlib_info; + + if (symfile_objfile == NULL) + return 0; + + if (!dld_cache.have_read_dld_descriptor) + if (!read_dld_descriptor ()) + return 0; + + return (pc >= dld_cache.dld_desc.text_base + && pc < dld_cache.dld_desc.text_base + dld_cache.dld_desc.text_size); +} + + +/* Return the GOT value for the shared library in which ADDR belongs. If + ADDR isn't in any known shared library, return zero. */ + +static CORE_ADDR +pa64_solib_get_got_by_pc (CORE_ADDR addr) +{ + struct so_list *so_list = master_so_list (); + CORE_ADDR got_value = 0; + + while (so_list) + { + if (so_list->lm_info->desc.text_base <= addr + && ((so_list->lm_info->desc.text_base + + so_list->lm_info->desc.text_size) + > addr)) + { + got_value = so_list->lm_info->desc.linkage_ptr; + break; + } + so_list = so_list->next; + } + return got_value; +} + +/* Get some HPUX-specific data from a shared lib. */ +static CORE_ADDR +pa64_solib_thread_start_addr (struct so_list *so) +{ + return so->lm_info->desc.tls_start_addr; +} + + +/* Return the address of the handle of the shared library in which ADDR + belongs. If ADDR isn't in any known shared library, return zero. + + This function is used in hppa_fix_call_dummy in hppa-tdep.c. */ + +static CORE_ADDR +pa64_solib_get_solib_by_pc (CORE_ADDR addr) +{ + struct so_list *so_list = master_so_list (); + CORE_ADDR retval = 0; + + while (so_list) + { + if (so_list->lm_info->desc.text_base <= addr + && ((so_list->lm_info->desc.text_base + + so_list->lm_info->desc.text_size) + > addr)) + { + retval = so_list->lm_info->desc_addr; + break; + } + so_list = so_list->next; + } + return retval; +} + +static struct target_so_ops pa64_so_ops; + +extern initialize_file_ftype _initialize_pa64_solib; /* -Wmissing-prototypes */ + +void +_initialize_pa64_solib (void) +{ + pa64_so_ops.relocate_section_addresses = pa64_relocate_section_addresses; + pa64_so_ops.free_so = pa64_free_so; + pa64_so_ops.clear_solib = pa64_clear_solib; + pa64_so_ops.solib_create_inferior_hook = pa64_solib_create_inferior_hook; + pa64_so_ops.special_symbol_handling = pa64_special_symbol_handling; + pa64_so_ops.current_sos = pa64_current_sos; + pa64_so_ops.open_symbol_file_object = pa64_open_symbol_file_object; + pa64_so_ops.in_dynsym_resolve_code = pa64_in_dynsym_resolve_code; + + memset (&dld_cache, 0, sizeof (dld_cache)); +} + +void pa64_solib_select (struct gdbarch_tdep *tdep) +{ + current_target_so_ops = &pa64_so_ops; + + tdep->solib_thread_start_addr = pa64_solib_thread_start_addr; + tdep->solib_get_got_by_pc = pa64_solib_get_got_by_pc; + tdep->solib_get_solib_by_pc = pa64_solib_get_solib_by_pc; +} + +#else /* PA_SOM_ONLY */ + +extern initialize_file_ftype _initialize_pa64_solib; /* -Wmissing-prototypes */ + +void +_initialize_pa64_solib (void) +{ +} + +void pa64_solib_select (struct gdbarch_tdep *tdep) +{ + /* For a SOM-only target, there is no pa64 solib support. This is needed + for hppa-hpux-tdep.c to build. */ + error ("Cannot select pa64 solib support for this configuration.\n"); +} +#endif |