diff options
author | Kevin Buettner <kevinb@redhat.com> | 2004-03-13 00:50:53 +0000 |
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committer | Kevin Buettner <kevinb@redhat.com> | 2004-03-13 00:50:53 +0000 |
commit | c4d1051556563d76c32f144c8442773ab42de419 (patch) | |
tree | a8a6f61bc49a4d206ddfac12db8f537c4dcd7c68 /gdb | |
parent | ed1bd989f78ed9daec1061f8ec2e6c298dfd4d16 (diff) | |
download | gdb-c4d1051556563d76c32f144c8442773ab42de419.zip gdb-c4d1051556563d76c32f144c8442773ab42de419.tar.gz gdb-c4d1051556563d76c32f144c8442773ab42de419.tar.bz2 |
Add shared library support for FR-V FDPIC ABI.
Diffstat (limited to 'gdb')
-rw-r--r-- | gdb/ChangeLog | 15 | ||||
-rw-r--r-- | gdb/Makefile.in | 3 | ||||
-rw-r--r-- | gdb/config/frv/frv.mt | 2 | ||||
-rw-r--r-- | gdb/config/frv/tm-frv.h | 2 | ||||
-rw-r--r-- | gdb/frv-tdep.c | 67 | ||||
-rw-r--r-- | gdb/frv-tdep.h | 9 | ||||
-rw-r--r-- | gdb/solib-frv.c | 1230 |
7 files changed, 1327 insertions, 1 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 8f195a1..6c79e8a 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,20 @@ 2004-03-12 Kevin Buettner <kevinb@redhat.com> + Add shared library support for FR-V FDPIC ABI: + * Makefile.in (solib-frv.o): Add dependencies. + * frv-tdep.c (find_func_descr, frv_convert_from_func_ptr_addr): + New functions. + (frv_push_dummy_call): Add support for FDPIC ABI. + (frv_gdbarch_init): Call set_gdbarch_convert_from_func_ptr_addr() + for FDPIC ABI. + * frv-tdep.h (frv_fdpic_find_global_pointer): Declare. + (frv_fdpic_find_canonical_descriptor): Declare. + * solib-frv.c: New file. + * config/frv/frv.mt (TDEPFILES): Add solib.o and solib-frv.o. + * config/frv/tm-frv.h (solib.h): Include. + +2004-03-12 Kevin Buettner <kevinb@redhat.com> + * Makefile.in (elf_frv_h, frv_tdep_h): Define. (frv-tdep.o): Update dependencies. * frv-tdep.h: New file. diff --git a/gdb/Makefile.in b/gdb/Makefile.in index 8bfed20..994850e 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -2298,6 +2298,9 @@ solib.o: solib.c $(defs_h) $(gdb_string_h) $(symtab_h) $(bfd_h) $(symfile_h) \ $(objfiles_h) $(gdbcore_h) $(command_h) $(target_h) $(frame_h) \ $(gdb_regex_h) $(inferior_h) $(environ_h) $(language_h) $(gdbcmd_h) \ $(completer_h) $(filenames_h) $(exec_h) $(solist_h) $(readline_h) +solib-frv.o: solib-frv.c $(defs_h) $(gdb_string_h) $(inferior_h) $(gdbcore_h) \ + $(solist_h) $(frv_tdep_h) $(objfiles_h) $(symtab_h) $(language_h) \ + $(command_h) $(gdbcmd_h) $(elf_frv_h) solib-irix.o: solib-irix.c $(defs_h) $(symtab_h) $(bfd_h) $(symfile_h) \ $(objfiles_h) $(gdbcore_h) $(target_h) $(inferior_h) $(solist_h) solib-legacy.o: solib-legacy.c $(defs_h) $(gdbcore_h) $(solib_svr4_h) diff --git a/gdb/config/frv/frv.mt b/gdb/config/frv/frv.mt index ae5521e..d782915 100644 --- a/gdb/config/frv/frv.mt +++ b/gdb/config/frv/frv.mt @@ -1,5 +1,5 @@ # Target: Fujitsu FRV processor -TDEPFILES= frv-tdep.o +TDEPFILES= frv-tdep.o solib.o solib-frv.o TM_FILE= tm-frv.h SIM_OBS = remote-sim.o SIM = ../sim/frv/libsim.a diff --git a/gdb/config/frv/tm-frv.h b/gdb/config/frv/tm-frv.h index a08f2d3..1215c58 100644 --- a/gdb/config/frv/tm-frv.h +++ b/gdb/config/frv/tm-frv.h @@ -43,3 +43,5 @@ extern CORE_ADDR frv_stopped_data_address(void); /* Use these macros for watchpoint insertion/deletion. */ #define target_stopped_data_address() frv_stopped_data_address() + +#include "solib.h" /* Include support for shared libraries. */ diff --git a/gdb/frv-tdep.c b/gdb/frv-tdep.c index 3c424b0..6020b38 100644 --- a/gdb/frv-tdep.c +++ b/gdb/frv-tdep.c @@ -1037,6 +1037,45 @@ frv_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp) } static CORE_ADDR +find_func_descr (struct gdbarch *gdbarch, CORE_ADDR entry_point) +{ + CORE_ADDR descr; + char valbuf[4]; + + descr = frv_fdpic_find_canonical_descriptor (entry_point); + + if (descr != 0) + return descr; + + /* Construct a non-canonical descriptor from space allocated on + the stack. */ + + descr = value_as_long (value_allocate_space_in_inferior (8)); + store_unsigned_integer (valbuf, 4, entry_point); + write_memory (descr, valbuf, 4); + store_unsigned_integer (valbuf, 4, + frv_fdpic_find_global_pointer (entry_point)); + write_memory (descr + 4, valbuf, 4); + return descr; +} + +static CORE_ADDR +frv_convert_from_func_ptr_addr (struct gdbarch *gdbarch, CORE_ADDR addr, + struct target_ops *targ) +{ + CORE_ADDR entry_point; + CORE_ADDR got_address; + + entry_point = get_target_memory_unsigned (targ, addr, 4); + got_address = get_target_memory_unsigned (targ, addr + 4, 4); + + if (got_address == frv_fdpic_find_global_pointer (entry_point)) + return entry_point; + else + return addr; +} + +static CORE_ADDR frv_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr, struct regcache *regcache, CORE_ADDR bp_addr, int nargs, struct value **args, CORE_ADDR sp, @@ -1053,6 +1092,7 @@ frv_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr, CORE_ADDR regval; int stack_space; int stack_offset; + enum frv_abi abi = frv_abi (gdbarch); #if 0 printf("Push %d args at sp = %x, struct_return=%d (%x)\n", @@ -1092,6 +1132,22 @@ frv_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr, len = 4; val = valbuf; } + else if (abi == FRV_ABI_FDPIC + && len == 4 + && typecode == TYPE_CODE_PTR + && TYPE_CODE (TYPE_TARGET_TYPE (arg_type)) == TYPE_CODE_FUNC) + { + /* The FDPIC ABI requires function descriptors to be passed instead + of entry points. */ + store_unsigned_integer + (valbuf, 4, + find_func_descr (gdbarch, + extract_unsigned_integer (VALUE_CONTENTS (arg), + 4))); + typecode = TYPE_CODE_PTR; + len = 4; + val = valbuf; + } else { val = (char *) VALUE_CONTENTS (arg); @@ -1129,6 +1185,14 @@ frv_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr, always at BP_ADDR. */ regcache_cooked_write_unsigned (regcache, lr_regnum, bp_addr); + if (abi == FRV_ABI_FDPIC) + { + /* Set the GOT register for the FDPIC ABI. */ + regcache_cooked_write_unsigned + (regcache, first_gpr_regnum + 15, + frv_fdpic_find_global_pointer (func_addr)); + } + /* Finally, update the SP register. */ regcache_cooked_write_unsigned (regcache, sp_regnum, sp); @@ -1449,6 +1513,9 @@ frv_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) } set_gdbarch_print_insn (gdbarch, print_insn_frv); + if (frv_abi (gdbarch) == FRV_ABI_FDPIC) + set_gdbarch_convert_from_func_ptr_addr (gdbarch, + frv_convert_from_func_ptr_addr); return gdbarch; } diff --git a/gdb/frv-tdep.h b/gdb/frv-tdep.h index 3bb9d84..5d95aa5 100644 --- a/gdb/frv-tdep.h +++ b/gdb/frv-tdep.h @@ -33,3 +33,12 @@ enum frv_abi frv_abi (struct gdbarch *gdbarch); not. (E.g, -1 will be returned if the ABI isn't the FDPIC ABI.) */ int frv_fdpic_loadmap_addresses (struct gdbarch *gdbarch, CORE_ADDR *interp_addr, CORE_ADDR *exec_addr); + +/* Given a function entry point, find and return the GOT address for the + containing load module. */ +CORE_ADDR frv_fdpic_find_global_pointer (CORE_ADDR addr); + +/* Given a function entry point, find and return the canonical descriptor + for that function, if one exists. If no canonical descriptor could + be found, return 0. */ +CORE_ADDR frv_fdpic_find_canonical_descriptor (CORE_ADDR entry_point); diff --git a/gdb/solib-frv.c b/gdb/solib-frv.c new file mode 100644 index 0000000..5995b80 --- /dev/null +++ b/gdb/solib-frv.c @@ -0,0 +1,1230 @@ +/* Handle FR-V (FDPIC) 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. */ + + +#include "defs.h" +#include "gdb_string.h" +#include "inferior.h" +#include "gdbcore.h" +#include "solist.h" +#include "frv-tdep.h" +#include "objfiles.h" +#include "symtab.h" +#include "language.h" +#include "command.h" +#include "gdbcmd.h" +#include "elf/frv.h" + +/* Flag which indicates whether internal debug messages should be printed. */ +static int solib_frv_debug; + +/* FR-V pointers are four bytes wide. */ +enum { FRV_PTR_SIZE = 4 }; + +/* Representation of loadmap and related structs for the FR-V FDPIC ABI. */ + +/* External versions; the size and alignment of the fields should be + the same as those on the target. When loaded, the placement of + the bits in each field will be the same as on the target. */ +typedef unsigned char ext_Elf32_Half[2]; +typedef unsigned char ext_Elf32_Addr[4]; +typedef unsigned char ext_Elf32_Word[4]; + +struct ext_elf32_fdpic_loadseg +{ + /* Core address to which the segment is mapped. */ + ext_Elf32_Addr addr; + /* VMA recorded in the program header. */ + ext_Elf32_Addr p_vaddr; + /* Size of this segment in memory. */ + ext_Elf32_Word p_memsz; +}; + +struct ext_elf32_fdpic_loadmap { + /* Protocol version number, must be zero. */ + ext_Elf32_Half version; + /* Number of segments in this map. */ + ext_Elf32_Half nsegs; + /* The actual memory map. */ + struct ext_elf32_fdpic_loadseg segs[1 /* nsegs, actually */]; +}; + +/* Internal versions; the types are GDB types and the data in each + of the fields is (or will be) decoded from the external struct + for ease of consumption. */ +struct int_elf32_fdpic_loadseg +{ + /* Core address to which the segment is mapped. */ + CORE_ADDR addr; + /* VMA recorded in the program header. */ + CORE_ADDR p_vaddr; + /* Size of this segment in memory. */ + long p_memsz; +}; + +struct int_elf32_fdpic_loadmap { + /* Protocol version number, must be zero. */ + int version; + /* Number of segments in this map. */ + int nsegs; + /* The actual memory map. */ + struct int_elf32_fdpic_loadseg segs[1 /* nsegs, actually */]; +}; + +/* Given address LDMADDR, fetch and decode the loadmap at that address. + Return NULL if there is a problem reading the target memory or if + there doesn't appear to be a loadmap at the given address. The + allocated space (representing the loadmap) returned by this + function may be freed via a single call to xfree(). */ + +static struct int_elf32_fdpic_loadmap * +fetch_loadmap (CORE_ADDR ldmaddr) +{ + struct ext_elf32_fdpic_loadmap ext_ldmbuf_partial; + struct ext_elf32_fdpic_loadmap *ext_ldmbuf; + struct int_elf32_fdpic_loadmap *int_ldmbuf; + int ext_ldmbuf_size, int_ldmbuf_size; + int version, seg, nsegs; + + /* Fetch initial portion of the loadmap. */ + if (target_read_memory (ldmaddr, (char *) &ext_ldmbuf_partial, + sizeof ext_ldmbuf_partial)) + { + /* Problem reading the target's memory. */ + return NULL; + } + + /* Extract the version. */ + version = extract_unsigned_integer (&ext_ldmbuf_partial.version, + sizeof ext_ldmbuf_partial.version); + if (version != 0) + { + /* We only handle version 0. */ + return NULL; + } + + /* Extract the number of segments. */ + nsegs = extract_unsigned_integer (&ext_ldmbuf_partial.nsegs, + sizeof ext_ldmbuf_partial.nsegs); + + /* Allocate space for the complete (external) loadmap. */ + ext_ldmbuf_size = sizeof (struct ext_elf32_fdpic_loadmap) + + (nsegs - 1) * sizeof (struct ext_elf32_fdpic_loadseg); + ext_ldmbuf = xmalloc (ext_ldmbuf_size); + + /* Copy over the portion of the loadmap that's already been read. */ + memcpy (ext_ldmbuf, &ext_ldmbuf_partial, sizeof ext_ldmbuf_partial); + + /* Read the rest of the loadmap from the target. */ + if (target_read_memory (ldmaddr + sizeof ext_ldmbuf_partial, + (char *) ext_ldmbuf + sizeof ext_ldmbuf_partial, + ext_ldmbuf_size - sizeof ext_ldmbuf_partial)) + { + /* Couldn't read rest of the loadmap. */ + xfree (ext_ldmbuf); + return NULL; + } + + /* Allocate space into which to put information extract from the + external loadsegs. I.e, allocate the internal loadsegs. */ + int_ldmbuf_size = sizeof (struct int_elf32_fdpic_loadmap) + + (nsegs - 1) * sizeof (struct int_elf32_fdpic_loadseg); + int_ldmbuf = xmalloc (int_ldmbuf_size); + + /* Place extracted information in internal structs. */ + int_ldmbuf->version = version; + int_ldmbuf->nsegs = nsegs; + for (seg = 0; seg < nsegs; seg++) + { + int_ldmbuf->segs[seg].addr + = extract_unsigned_integer (&ext_ldmbuf->segs[seg].addr, + sizeof (ext_ldmbuf->segs[seg].addr)); + int_ldmbuf->segs[seg].p_vaddr + = extract_unsigned_integer (&ext_ldmbuf->segs[seg].p_vaddr, + sizeof (ext_ldmbuf->segs[seg].p_vaddr)); + int_ldmbuf->segs[seg].p_memsz + = extract_unsigned_integer (&ext_ldmbuf->segs[seg].p_memsz, + sizeof (ext_ldmbuf->segs[seg].p_memsz)); + } + + free (ext_ldmbuf); + return int_ldmbuf; +} + +/* External link_map and elf32_fdpic_loadaddr struct definitions. */ + +typedef unsigned char ext_ptr[4]; + +struct ext_elf32_fdpic_loadaddr +{ + ext_ptr map; /* struct elf32_fdpic_loadmap *map; */ + ext_ptr got_value; /* void *got_value; */ +}; + +struct ext_link_map +{ + struct ext_elf32_fdpic_loadaddr l_addr; + + /* Absolute file name object was found in. */ + ext_ptr l_name; /* char *l_name; */ + + /* Dynamic section of the shared object. */ + ext_ptr l_ld; /* ElfW(Dyn) *l_ld; */ + + /* Chain of loaded objects. */ + ext_ptr l_next, l_prev; /* struct link_map *l_next, *l_prev; */ +}; + +/* Link map info to include in an allocated so_list entry */ + +struct lm_info + { + /* The loadmap, digested into an easier to use form. */ + struct int_elf32_fdpic_loadmap *map; + /* The GOT address for this link map entry. */ + CORE_ADDR got_value; + + /* Cached dynamic symbol table and dynamic relocs initialized and + used only by find_canonical_descriptor_in_load_object(). + + Note: kevinb/2004-02-26: It appears that calls to + bfd_canonicalize_dynamic_reloc() will use the same symbols as + those supplied to the first call to this function. Therefore, + it's important to NOT free the asymbol ** data structure + supplied to the first call. Thus the caching of the dynamic + symbols (dyn_syms) is critical for correct operation. The + caching of the dynamic relocations could be dispensed with. */ + asymbol **dyn_syms; + arelent **dyn_relocs; + int dyn_reloc_count; /* number of dynamic relocs. */ + + }; + +/* The load map, got value, etc. are not available from the chain + of loaded shared objects. ``main_executable_lm_info'' provides + a way to get at this information so that it doesn't need to be + frequently recomputed. Initialized by frv_relocate_main_executable(). */ +static struct lm_info *main_executable_lm_info; + +static void frv_relocate_main_executable (void); +static CORE_ADDR main_got (void); +static int enable_break2 (void); + +/* + + 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 (bfd *abfd, char *symname) +{ + long 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); + } + + if (symaddr) + return symaddr; + + /* Look for the symbol in the dynamic string table too. */ + + storage_needed = bfd_get_dynamic_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_dynamic_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; +} + + +/* + + LOCAL FUNCTION + + open_symbol_file_object + + SYNOPSIS + + void open_symbol_file_object (void *from_tty) + + DESCRIPTION + + If no open symbol file, attempt to locate and open the main symbol + file. + + If FROM_TTYP dereferences to a non-zero integer, allow messages to + be printed. This parameter is a pointer rather than an int because + open_symbol_file_object() is called via catch_errors() and + catch_errors() requires a pointer argument. */ + +static int +open_symbol_file_object (void *from_ttyp) +{ + /* Unimplemented. */ + return 0; +} + +/* Cached value for lm_base(), below. */ +static CORE_ADDR lm_base_cache = 0; + +/* Return the address from which the link map chain may be found. On + the FR-V, this may be found in a number of ways. Assuming that the + main executable has already been relocated, the easiest way to find + this value is to look up the address of _GLOBAL_OFFSET_TABLE_. A + pointer to the start of the link map will be located at the word found + at _GLOBAL_OFFSET_TABLE_ + 8. (This is part of the dynamic linker + reserve area mandated by the ABI.) */ + +static CORE_ADDR +lm_base (void) +{ + struct minimal_symbol *got_sym; + CORE_ADDR addr; + char buf[FRV_PTR_SIZE]; + + /* If we already have a cached value, return it. */ + if (lm_base_cache) + return lm_base_cache; + + got_sym = lookup_minimal_symbol ("_GLOBAL_OFFSET_TABLE_", NULL, + symfile_objfile); + if (got_sym == 0) + { + if (solib_frv_debug) + fprintf_unfiltered (gdb_stdlog, + "lm_base: _GLOBAL_OFFSET_TABLE_ not found.\n"); + return 0; + } + + addr = SYMBOL_VALUE_ADDRESS (got_sym) + 8; + + if (solib_frv_debug) + fprintf_unfiltered (gdb_stdlog, + "lm_base: _GLOBAL_OFFSET_TABLE_ + 8 = %s\n", + local_hex_string_custom (addr, "08l")); + + if (target_read_memory (addr, buf, sizeof buf) != 0) + return 0; + lm_base_cache = extract_unsigned_integer (buf, sizeof buf); + + if (solib_frv_debug) + fprintf_unfiltered (gdb_stdlog, + "lm_base: lm_base_cache = %s\n", + local_hex_string_custom (lm_base_cache, "08l")); + + return lm_base_cache; +} + + +/* LOCAL FUNCTION + + frv_current_sos -- build a list of currently loaded shared objects + + SYNOPSIS + + struct so_list *frv_current_sos () + + DESCRIPTION + + Build a list of `struct so_list' objects describing the shared + objects currently loaded in the inferior. This list does not + include an entry for the main executable file. + + Note that we only gather information directly available from the + inferior --- we don't examine any of the shared library files + themselves. The declaration of `struct so_list' says which fields + we provide values for. */ + +static struct so_list * +frv_current_sos (void) +{ + CORE_ADDR lm_addr, mgot; + struct so_list *sos_head = NULL; + struct so_list **sos_next_ptr = &sos_head; + + mgot = main_got (); + + /* Locate the address of the first link map struct. */ + lm_addr = lm_base (); + + /* We have at least one link map entry. Fetch the the lot of them, + building the solist chain. */ + while (lm_addr) + { + struct ext_link_map lm_buf; + CORE_ADDR got_addr; + + if (solib_frv_debug) + fprintf_unfiltered (gdb_stdlog, + "current_sos: reading link_map entry at %s\n", + local_hex_string_custom (lm_addr, "08l")); + + if (target_read_memory (lm_addr, (char *) &lm_buf, sizeof (lm_buf)) != 0) + { + warning ("frv_current_sos: Unable to read link map entry. Shared object chain may be incomplete."); + break; + } + + got_addr + = extract_unsigned_integer (&lm_buf.l_addr.got_value, + sizeof (lm_buf.l_addr.got_value)); + /* If the got_addr is the same as mgotr, then we're looking at the + entry for the main executable. By convention, we don't include + this in the list of shared objects. */ + if (got_addr != mgot) + { + int errcode; + char *name_buf; + struct int_elf32_fdpic_loadmap *loadmap; + struct so_list *sop; + CORE_ADDR addr; + + /* Fetch the load map address. */ + addr = extract_unsigned_integer (&lm_buf.l_addr.map, + sizeof lm_buf.l_addr.map); + loadmap = fetch_loadmap (addr); + if (loadmap == NULL) + { + warning ("frv_current_sos: Unable to fetch load map. Shared object chain may be incomplete."); + break; + } + + sop = xcalloc (1, sizeof (struct so_list)); + sop->lm_info = xcalloc (1, sizeof (struct lm_info)); + sop->lm_info->map = loadmap; + sop->lm_info->got_value = got_addr; + /* Fetch the name. */ + addr = extract_unsigned_integer (&lm_buf.l_name, + sizeof (lm_buf.l_name)); + target_read_string (addr, &name_buf, SO_NAME_MAX_PATH_SIZE - 1, + &errcode); + + if (solib_frv_debug) + fprintf_unfiltered (gdb_stdlog, "current_sos: name = %s\n", + name_buf); + + if (errcode != 0) + { + warning ("frv_current_sos: Can't read pathname for link map entry: %s\n", + safe_strerror (errcode)); + } + else + { + strncpy (sop->so_name, name_buf, SO_NAME_MAX_PATH_SIZE - 1); + sop->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; + xfree (name_buf); + strcpy (sop->so_original_name, sop->so_name); + } + + *sos_next_ptr = sop; + sos_next_ptr = &sop->next; + } + + lm_addr = extract_unsigned_integer (&lm_buf.l_next, sizeof (lm_buf.l_next)); + } + + enable_break2 (); + + return sos_head; +} + + +/* Return 1 if PC lies in the dynamic symbol resolution code of the + run time loader. */ + +static CORE_ADDR interp_text_sect_low; +static CORE_ADDR interp_text_sect_high; +static CORE_ADDR interp_plt_sect_low; +static CORE_ADDR interp_plt_sect_high; + +static int +frv_in_dynsym_resolve_code (CORE_ADDR pc) +{ + return ((pc >= interp_text_sect_low && pc < interp_text_sect_high) + || (pc >= interp_plt_sect_low && pc < interp_plt_sect_high) + || in_plt_section (pc, NULL)); +} + +/* Given a loadmap and an address, return the displacement needed + to relocate the address. */ + +CORE_ADDR +displacement_from_map (struct int_elf32_fdpic_loadmap *map, + CORE_ADDR addr) +{ + int seg; + + for (seg = 0; seg < map->nsegs; seg++) + { + if (map->segs[seg].p_vaddr <= addr + && addr < map->segs[seg].p_vaddr + map->segs[seg].p_memsz) + { + return map->segs[seg].addr - map->segs[seg].p_vaddr; + } + } + + return 0; +} + +/* Print a warning about being unable to set the dynamic linker + breakpoint. */ + +static void +enable_break_failure_warning (void) +{ + warning ("Unable to find dynamic linker breakpoint function.\n" + "GDB will be unable to debug shared library initializers\n" + "and track explicitly loaded dynamic code."); +} + +/* + + LOCAL FUNCTION + + enable_break -- arrange for dynamic linker to hit breakpoint + + SYNOPSIS + + int enable_break (void) + + DESCRIPTION + + The dynamic linkers has, as part of its debugger interface, support + for arranging for the inferior to hit a breakpoint after mapping in + the shared libraries. This function enables that breakpoint. + + On the FR-V, using the shared library (FDPIC) ABI, the symbol + _dl_debug_addr points to the r_debug struct which contains + a field called r_brk. r_brk is the address of the function + descriptor upon which a breakpoint must be placed. Being a + function descriptor, we must extract the entry point in order + to set the breakpoint. + + Our strategy will be to get the .interp section from the + executable. This section will provide us with the name of the + interpreter. We'll open the interpreter and then look up + the address of _dl_debug_addr. We then relocate this address + using the interpreter's loadmap. Once the relocated address + is known, we fetch the value (address) corresponding to r_brk + and then use that value to fetch the entry point of the function + we're interested in. + + */ + +static int enable_break1_done = 0; +static int enable_break2_done = 0; + +static int +enable_break2 (void) +{ + int success = 0; + char **bkpt_namep; + asection *interp_sect; + + if (!enable_break1_done || enable_break2_done) + return 1; + + enable_break2_done = 1; + + /* First, remove all the solib event breakpoints. Their addresses + may have changed since the last time we ran the program. */ + remove_solib_event_breakpoints (); + + 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; + bfd *tmp_bfd = NULL; + int tmp_fd = -1; + char *tmp_pathname = NULL; + int status; + CORE_ADDR addr, interp_loadmap_addr; + char addr_buf[FRV_PTR_SIZE]; + struct int_elf32_fdpic_loadmap *ldm; + + /* 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_fd = solib_open (buf, &tmp_pathname); + if (tmp_fd >= 0) + tmp_bfd = bfd_fdopenr (tmp_pathname, gnutarget, tmp_fd); + + if (tmp_bfd == NULL) + { + enable_break_failure_warning (); + return 0; + } + + /* Make sure the dynamic linker is really a useful object. */ + if (!bfd_check_format (tmp_bfd, bfd_object)) + { + warning ("Unable to grok dynamic linker %s as an object file", buf); + enable_break_failure_warning (); + bfd_close (tmp_bfd); + return 0; + } + + status = frv_fdpic_loadmap_addresses (current_gdbarch, + &interp_loadmap_addr, 0); + if (status < 0) + { + warning ("Unable to determine dynamic linker loadmap address\n"); + enable_break_failure_warning (); + bfd_close (tmp_bfd); + return 0; + } + + if (solib_frv_debug) + fprintf_unfiltered (gdb_stdlog, + "enable_break: interp_loadmap_addr = %s\n", + local_hex_string_custom (interp_loadmap_addr, + "08l")); + + ldm = fetch_loadmap (interp_loadmap_addr); + if (ldm == NULL) + { + warning ("Unable to load dynamic linker loadmap at address %s\n", + local_hex_string_custom (interp_loadmap_addr, "08l")); + enable_break_failure_warning (); + bfd_close (tmp_bfd); + return 0; + } + + /* Record the relocated start and end address of the dynamic linker + text and plt section for svr4_in_dynsym_resolve_code. */ + interp_sect = bfd_get_section_by_name (tmp_bfd, ".text"); + if (interp_sect) + { + interp_text_sect_low + = bfd_section_vma (tmp_bfd, interp_sect); + interp_text_sect_low + += displacement_from_map (ldm, interp_text_sect_low); + 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); + interp_plt_sect_low + += displacement_from_map (ldm, interp_plt_sect_low); + interp_plt_sect_high = + interp_plt_sect_low + bfd_section_size (tmp_bfd, interp_sect); + } + + addr = bfd_lookup_symbol (tmp_bfd, "_dl_debug_addr"); + if (addr == 0) + { + warning ("Could not find symbol _dl_debug_addr in dynamic linker"); + enable_break_failure_warning (); + bfd_close (tmp_bfd); + return 0; + } + + if (solib_frv_debug) + fprintf_unfiltered (gdb_stdlog, + "enable_break: _dl_debug_addr (prior to relocation) = %s\n", + local_hex_string_custom (addr, "08l")); + + addr += displacement_from_map (ldm, addr); + + if (solib_frv_debug) + fprintf_unfiltered (gdb_stdlog, + "enable_break: _dl_debug_addr (after relocation) = %s\n", + local_hex_string_custom (addr, "08l")); + + /* Fetch the address of the r_debug struct. */ + if (target_read_memory (addr, addr_buf, sizeof addr_buf) != 0) + { + warning ("Unable to fetch contents of _dl_debug_addr (at address %s) from dynamic linker", + local_hex_string_custom (addr, "08l")); + } + addr = extract_unsigned_integer (addr_buf, sizeof addr_buf); + + /* Fetch the r_brk field. It's 8 bytes from the start of + _dl_debug_addr. */ + if (target_read_memory (addr + 8, addr_buf, sizeof addr_buf) != 0) + { + warning ("Unable to fetch _dl_debug_addr->r_brk (at address %s) from dynamic linker", + local_hex_string_custom (addr + 8, "08l")); + enable_break_failure_warning (); + bfd_close (tmp_bfd); + return 0; + } + addr = extract_unsigned_integer (addr_buf, sizeof addr_buf); + + /* Now fetch the function entry point. */ + if (target_read_memory (addr, addr_buf, sizeof addr_buf) != 0) + { + warning ("Unable to fetch _dl_debug_addr->.r_brk entry point (at address %s) from dynamic linker", + local_hex_string_custom (addr, "08l")); + enable_break_failure_warning (); + bfd_close (tmp_bfd); + return 0; + } + addr = extract_unsigned_integer (addr_buf, sizeof addr_buf); + + /* We're done with the temporary bfd. */ + bfd_close (tmp_bfd); + + /* We're also done with the loadmap. */ + xfree (ldm); + + /* Now (finally!) create the solib breakpoint. */ + create_solib_event_breakpoint (addr); + + return 1; + } + + /* Tell the user we couldn't set a dynamic linker breakpoint. */ + enable_break_failure_warning (); + + /* Failure return. */ + return 0; +} + +static int +enable_break (void) +{ + asection *interp_sect; + + /* Remove all the solib event breakpoints. Their addresses + may have changed since the last time we ran the program. */ + remove_solib_event_breakpoints (); + + /* Check for the presence of a .interp section. If there is no + such section, the executable is statically linked. */ + + interp_sect = bfd_get_section_by_name (exec_bfd, ".interp"); + + if (interp_sect) + { + enable_break1_done = 1; + create_solib_event_breakpoint (symfile_objfile->ei.entry_point); + + if (solib_frv_debug) + fprintf_unfiltered (gdb_stdlog, + "enable_break: solib event breakpoint placed at entry point: %s\n", + local_hex_string_custom + (symfile_objfile->ei.entry_point, "08l")); + } + else + { + if (solib_frv_debug) + fprintf_unfiltered (gdb_stdlog, + "enable_break: No .interp section found.\n"); + } + + return 1; +} + +/* + + LOCAL FUNCTION + + special_symbol_handling -- additional shared library symbol handling + + SYNOPSIS + + void special_symbol_handling () + + 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. + + */ + +static void +frv_special_symbol_handling (void) +{ + /* Nothing needed (yet) for FRV. */ +} + +static void +frv_relocate_main_executable (void) +{ + int status; + CORE_ADDR exec_addr; + struct int_elf32_fdpic_loadmap *ldm; + struct cleanup *old_chain; + struct section_offsets *new_offsets; + int changed; + struct obj_section *osect; + + status = frv_fdpic_loadmap_addresses (current_gdbarch, 0, &exec_addr); + + if (status < 0) + { + /* Not using FDPIC ABI, so do nothing. */ + return; + } + + /* Fetch the loadmap located at ``exec_addr''. */ + ldm = fetch_loadmap (exec_addr); + if (ldm == NULL) + error ("Unable to load the executable's loadmap."); + + if (main_executable_lm_info) + xfree (main_executable_lm_info); + main_executable_lm_info = xcalloc (1, sizeof (struct lm_info)); + main_executable_lm_info->map = ldm; + + new_offsets = xcalloc (symfile_objfile->num_sections, + sizeof (struct section_offsets)); + old_chain = make_cleanup (xfree, new_offsets); + changed = 0; + + ALL_OBJFILE_OSECTIONS (symfile_objfile, osect) + { + CORE_ADDR orig_addr, addr, offset; + int osect_idx; + int seg; + + osect_idx = osect->the_bfd_section->index; + + /* Current address of section. */ + addr = osect->addr; + /* Offset from where this section started. */ + offset = ANOFFSET (symfile_objfile->section_offsets, osect_idx); + /* Original address prior to any past relocations. */ + orig_addr = addr - offset; + + for (seg = 0; seg < ldm->nsegs; seg++) + { + if (ldm->segs[seg].p_vaddr <= orig_addr + && orig_addr < ldm->segs[seg].p_vaddr + ldm->segs[seg].p_memsz) + { + new_offsets->offsets[osect_idx] + = ldm->segs[seg].addr - ldm->segs[seg].p_vaddr; + + if (new_offsets->offsets[osect_idx] != offset) + changed = 1; + break; + } + } + } + + if (changed) + objfile_relocate (symfile_objfile, new_offsets); + + do_cleanups (old_chain); + + /* Now that symfile_objfile has been relocated, we can compute the + GOT value and stash it away. */ + main_executable_lm_info->got_value = main_got (); +} + +/* + + GLOBAL FUNCTION + + frv_solib_create_inferior_hook -- shared library startup support + + SYNOPSIS + + void frv_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 the FR-V shared library ABI (FDPIC), the main executable + needs to be relocated. The shared library breakpoints also need + to be enabled. + */ + +static void +frv_solib_create_inferior_hook (void) +{ + /* Relocate main executable. */ + frv_relocate_main_executable (); + + /* Enable shared library breakpoints. */ + if (!enable_break ()) + { + warning ("shared library handler failed to enable breakpoint"); + return; + } +} + +static void +frv_clear_solib (void) +{ + lm_base_cache = 0; + enable_break1_done = 0; + enable_break2_done = 0; +} + +static void +frv_free_so (struct so_list *so) +{ + xfree (so->lm_info->map); + xfree (so->lm_info->dyn_syms); + xfree (so->lm_info->dyn_relocs); + xfree (so->lm_info); +} + +static void +frv_relocate_section_addresses (struct so_list *so, + struct section_table *sec) +{ + int seg; + struct int_elf32_fdpic_loadmap *map; + + map = so->lm_info->map; + + for (seg = 0; seg < map->nsegs; seg++) + { + if (map->segs[seg].p_vaddr <= sec->addr + && sec->addr < map->segs[seg].p_vaddr + map->segs[seg].p_memsz) + { + CORE_ADDR displ = map->segs[seg].addr - map->segs[seg].p_vaddr; + sec->addr += displ; + sec->endaddr += displ; + break; + } + } +} + +/* Return the GOT address associated with the main executable. Return + 0 if it can't be found. */ + +static CORE_ADDR +main_got (void) +{ + struct minimal_symbol *got_sym; + + got_sym = lookup_minimal_symbol ("_GLOBAL_OFFSET_TABLE_", NULL, symfile_objfile); + if (got_sym == 0) + return 0; + + return SYMBOL_VALUE_ADDRESS (got_sym); +} + +/* Find the global pointer for the given function address ADDR. */ + +CORE_ADDR +frv_fdpic_find_global_pointer (CORE_ADDR addr) +{ + struct so_list *so; + + so = master_so_list (); + while (so) + { + int seg; + struct int_elf32_fdpic_loadmap *map; + + map = so->lm_info->map; + + for (seg = 0; seg < map->nsegs; seg++) + { + if (map->segs[seg].addr <= addr + && addr < map->segs[seg].addr + map->segs[seg].p_memsz) + return so->lm_info->got_value; + } + + so = so->next; + } + + /* Didn't find it it any of the shared objects. So assume it's in the + main executable. */ + return main_got (); +} + +/* Forward declarations for frv_fdpic_find_canonical_descriptor(). */ +static CORE_ADDR find_canonical_descriptor_in_load_object + (CORE_ADDR, CORE_ADDR, char *, bfd *, struct lm_info *); + +/* Given a function entry point, attempt to find the canonical descriptor + associated with that entry point. Return 0 if no canonical descriptor + could be found. */ + +CORE_ADDR +frv_fdpic_find_canonical_descriptor (CORE_ADDR entry_point) +{ + char *name; + CORE_ADDR addr; + CORE_ADDR got_value; + struct int_elf32_fdpic_loadmap *ldm = 0; + struct symbol *sym; + int status; + CORE_ADDR exec_loadmap_addr; + + /* Fetch the corresponding global pointer for the entry point. */ + got_value = frv_fdpic_find_global_pointer (entry_point); + + /* Attempt to find the name of the function. If the name is available, + it'll be used as an aid in finding matching functions in the dynamic + symbol table. */ + sym = find_pc_function (entry_point); + if (sym == 0) + name = 0; + else + name = SYMBOL_LINKAGE_NAME (sym); + + /* Check the main executable. */ + addr = find_canonical_descriptor_in_load_object + (entry_point, got_value, name, symfile_objfile->obfd, + main_executable_lm_info); + + /* If descriptor not found via main executable, check each load object + in list of shared objects. */ + if (addr == 0) + { + struct so_list *so; + + so = master_so_list (); + while (so) + { + addr = find_canonical_descriptor_in_load_object + (entry_point, got_value, name, so->abfd, so->lm_info); + + if (addr != 0) + break; + + so = so->next; + } + } + + return addr; +} + +static CORE_ADDR +find_canonical_descriptor_in_load_object + (CORE_ADDR entry_point, CORE_ADDR got_value, char *name, bfd *abfd, + struct lm_info *lm) +{ + arelent *rel; + unsigned int i; + CORE_ADDR addr = 0; + + /* Nothing to do if no bfd. */ + if (abfd == 0) + return 0; + + /* We want to scan the dynamic relocs for R_FRV_FUNCDESC relocations. + (More about this later.) But in order to fetch the relocs, we + need to first fetch the dynamic symbols. These symbols need to + be cached due to the way that bfd_canonicalize_dynamic_reloc() + works. (See the comments in the declaration of struct lm_info + for more information.) */ + if (lm->dyn_syms == NULL) + { + long storage_needed; + unsigned int number_of_symbols; + + /* Determine amount of space needed to hold the dynamic symbol table. */ + storage_needed = bfd_get_dynamic_symtab_upper_bound (abfd); + + /* If there are no dynamic symbols, there's nothing to do. */ + if (storage_needed <= 0) + return 0; + + /* Allocate space for the dynamic symbol table. */ + lm->dyn_syms = (asymbol **) xmalloc (storage_needed); + + /* Fetch the dynamic symbol table. */ + number_of_symbols = bfd_canonicalize_dynamic_symtab (abfd, lm->dyn_syms); + + if (number_of_symbols == 0) + return 0; + } + + /* Fetch the dynamic relocations if not already cached. */ + if (lm->dyn_relocs == NULL) + { + long storage_needed; + + /* Determine amount of space needed to hold the dynamic relocs. */ + storage_needed = bfd_get_dynamic_reloc_upper_bound (abfd); + + /* Bail out if there are no dynamic relocs. */ + if (storage_needed <= 0) + return 0; + + /* Allocate space for the relocs. */ + lm->dyn_relocs = (arelent **) xmalloc (storage_needed); + + /* Fetch the dynamic relocs. */ + lm->dyn_reloc_count + = bfd_canonicalize_dynamic_reloc (abfd, lm->dyn_relocs, lm->dyn_syms); + } + + /* Search the dynamic relocs. */ + for (i = 0; i < lm->dyn_reloc_count; i++) + { + rel = lm->dyn_relocs[i]; + + /* Relocs of interest are those which meet the following + criteria: + + - the names match (assuming the caller could provide + a name which matches ``entry_point''). + - the relocation type must be R_FRV_FUNCDESC. Relocs + of this type are used (by the dynamic linker) to + look up the address of a canonical descriptor (allocating + it if need be) and initializing the GOT entry referred + to by the offset to the address of the descriptor. + + These relocs of interest may be used to obtain a + candidate descriptor by first adjusting the reloc's + address according to the link map and then dereferencing + this address (which is a GOT entry) to obtain a descriptor + address. */ + if ((name == 0 || strcmp (name, (*rel->sym_ptr_ptr)->name) == 0) + && rel->howto->type == R_FRV_FUNCDESC) + { + char buf[FRV_PTR_SIZE]; + + /* Compute address of address of candidate descriptor. */ + addr = rel->address + displacement_from_map (lm->map, rel->address); + + /* Fetch address of candidate descriptor. */ + if (target_read_memory (addr, buf, sizeof buf) != 0) + continue; + addr = extract_unsigned_integer (buf, sizeof buf); + + /* Check for matching entry point. */ + if (target_read_memory (addr, buf, sizeof buf) != 0) + continue; + if (extract_unsigned_integer (buf, sizeof buf) != entry_point) + continue; + + /* Check for matching got value. */ + if (target_read_memory (addr + 4, buf, sizeof buf) != 0) + continue; + if (extract_unsigned_integer (buf, sizeof buf) != got_value) + continue; + + /* Match was successful! Exit loop. */ + break; + } + } + + return addr; +} + +static struct target_so_ops frv_so_ops; + +void +_initialize_frv_solib (void) +{ + frv_so_ops.relocate_section_addresses = frv_relocate_section_addresses; + frv_so_ops.free_so = frv_free_so; + frv_so_ops.clear_solib = frv_clear_solib; + frv_so_ops.solib_create_inferior_hook = frv_solib_create_inferior_hook; + frv_so_ops.special_symbol_handling = frv_special_symbol_handling; + frv_so_ops.current_sos = frv_current_sos; + frv_so_ops.open_symbol_file_object = open_symbol_file_object; + frv_so_ops.in_dynsym_resolve_code = frv_in_dynsym_resolve_code; + + /* FIXME: Don't do this here. *_gdbarch_init() should set so_ops. */ + current_target_so_ops = &frv_so_ops; + + /* Debug this file's internals. */ + add_show_from_set (add_set_cmd ("solib-frv", class_maintenance, var_zinteger, + &solib_frv_debug, +"Set internal debugging of shared library code for FR-V.\n" +"When non-zero, FR-V solib specific internal debugging is enabled.", + &setdebuglist), + &showdebuglist); +} |