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- /* Handle FR-V (FDPIC) shared libraries for GDB, the GNU Debugger.
- Copyright (C) 2004-2022 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 3 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, see <http://www.gnu.org/licenses/>. */
- #include "defs.h"
- #include "inferior.h"
- #include "gdbcore.h"
- #include "solib.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"
- #include "gdb_bfd.h"
- /* Flag which indicates whether internal debug messages should be printed. */
- static unsigned 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 gdb_byte ext_Elf32_Half[2];
- typedef gdb_byte ext_Elf32_Addr[4];
- typedef gdb_byte 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)
- {
- enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
- 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, (gdb_byte *) &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,
- byte_order);
- 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,
- byte_order);
- if (nsegs <= 0)
- return NULL;
- /* 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 = (struct ext_elf32_fdpic_loadmap *) 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,
- (gdb_byte *) 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 = (struct int_elf32_fdpic_loadmap *) 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),
- byte_order);
- int_ldmbuf->segs[seg].p_vaddr
- = extract_unsigned_integer (ext_ldmbuf->segs[seg].p_vaddr,
- sizeof (ext_ldmbuf->segs[seg].p_vaddr),
- byte_order);
- int_ldmbuf->segs[seg].p_memsz
- = extract_unsigned_integer (ext_ldmbuf->segs[seg].p_memsz,
- sizeof (ext_ldmbuf->segs[seg].p_memsz),
- byte_order);
- }
- xfree (ext_ldmbuf);
- return int_ldmbuf;
- }
- /* External link_map and elf32_fdpic_loadaddr struct definitions. */
- typedef gdb_byte 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_frv : public lm_info_base
- {
- ~lm_info_frv ()
- {
- xfree (this->map);
- xfree (this->dyn_syms);
- xfree (this->dyn_relocs);
- }
- /* The loadmap, digested into an easier to use form. */
- int_elf32_fdpic_loadmap *map = NULL;
- /* The GOT address for this link map entry. */
- CORE_ADDR got_value = 0;
- /* The link map address, needed for frv_fetch_objfile_link_map(). */
- CORE_ADDR lm_addr = 0;
- /* 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 = NULL;
- arelent **dyn_relocs = NULL;
- int dyn_reloc_count = 0; /* 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 lm_info_frv *main_executable_lm_info;
- static void frv_relocate_main_executable (void);
- static CORE_ADDR main_got (void);
- static int enable_break2 (void);
- /* Implement the "open_symbol_file_object" target_so_ops method. */
- static int
- open_symbol_file_object (int from_tty)
- {
- /* Unimplemented. */
- return 0;
- }
- /* Cached value for lm_base(), below. */
- static CORE_ADDR lm_base_cache = 0;
- /* Link map address for main module. */
- static CORE_ADDR main_lm_addr = 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)
- {
- enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
- struct bound_minimal_symbol got_sym;
- CORE_ADDR addr;
- gdb_byte buf[FRV_PTR_SIZE];
- /* One of our assumptions is that the main executable has been relocated.
- Bail out if this has not happened. (Note that post_create_inferior()
- in infcmd.c will call solib_add prior to solib_create_inferior_hook().
- If we allow this to happen, lm_base_cache will be initialized with
- a bogus value. */
- if (main_executable_lm_info == 0)
- return 0;
- /* 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,
- current_program_space->symfile_object_file);
- if (got_sym.minsym == 0)
- {
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "lm_base: _GLOBAL_OFFSET_TABLE_ not found.\n");
- return 0;
- }
- addr = BMSYMBOL_VALUE_ADDRESS (got_sym) + 8;
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "lm_base: _GLOBAL_OFFSET_TABLE_ + 8 = %s\n",
- hex_string_custom (addr, 8));
- if (target_read_memory (addr, buf, sizeof buf) != 0)
- return 0;
- lm_base_cache = extract_unsigned_integer (buf, sizeof buf, byte_order);
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "lm_base: lm_base_cache = %s\n",
- hex_string_custom (lm_base_cache, 8));
- return lm_base_cache;
- }
- /* Implement the "current_sos" target_so_ops method. */
- static struct so_list *
- frv_current_sos (void)
- {
- enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
- CORE_ADDR lm_addr, mgot;
- struct so_list *sos_head = NULL;
- struct so_list **sos_next_ptr = &sos_head;
- /* Make sure that the main executable has been relocated. This is
- required in order to find the address of the global offset table,
- which in turn is used to find the link map info. (See lm_base()
- for details.)
- Note that the relocation of the main executable is also performed
- by solib_create_inferior_hook(), however, in the case of core
- files, this hook is called too late in order to be of benefit to
- solib_add. solib_add eventually calls this this function,
- frv_current_sos, and also precedes the call to
- solib_create_inferior_hook(). (See post_create_inferior() in
- infcmd.c.) */
- if (main_executable_lm_info == 0 && core_bfd != NULL)
- frv_relocate_main_executable ();
- /* Fetch the GOT corresponding to the main executable. */
- 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 lot of them,
- building the solist chain. */
- while (lm_addr)
- {
- struct ext_link_map lm_buf;
- CORE_ADDR got_addr;
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "current_sos: reading link_map entry at %s\n",
- hex_string_custom (lm_addr, 8));
- if (target_read_memory (lm_addr, (gdb_byte *) &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),
- byte_order);
- /* 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)
- {
- 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,
- byte_order);
- loadmap = fetch_loadmap (addr);
- if (loadmap == NULL)
- {
- warning (_("frv_current_sos: Unable to fetch load map. "
- "Shared object chain may be incomplete."));
- break;
- }
- sop = XCNEW (struct so_list);
- lm_info_frv *li = new lm_info_frv;
- sop->lm_info = li;
- li->map = loadmap;
- li->got_value = got_addr;
- li->lm_addr = lm_addr;
- /* Fetch the name. */
- addr = extract_unsigned_integer (lm_buf.l_name,
- sizeof (lm_buf.l_name),
- byte_order);
- gdb::unique_xmalloc_ptr<char> name_buf
- = target_read_string (addr, SO_NAME_MAX_PATH_SIZE - 1);
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog, "current_sos: name = %s\n",
- name_buf.get ());
-
- if (name_buf == nullptr)
- warning (_("Can't read pathname for link map entry."));
- else
- {
- strncpy (sop->so_name, name_buf.get (),
- SO_NAME_MAX_PATH_SIZE - 1);
- sop->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
- strcpy (sop->so_original_name, sop->so_name);
- }
- *sos_next_ptr = sop;
- sos_next_ptr = &sop->next;
- }
- else
- {
- main_lm_addr = lm_addr;
- }
- lm_addr = extract_unsigned_integer (lm_buf.l_next,
- sizeof (lm_buf.l_next), byte_order);
- }
- 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));
- }
- /* Given a loadmap and an address, return the displacement needed
- to relocate the address. */
- static 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."));
- }
- /* Helper function for gdb_bfd_lookup_symbol. */
- static int
- cmp_name (const asymbol *sym, const void *data)
- {
- return (strcmp (sym->name, (const char *) data) == 0);
- }
- /* Arrange for dynamic linker to hit breakpoint.
- 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_break2_done = 0;
- static int
- enable_break2 (void)
- {
- enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
- asection *interp_sect;
- if (enable_break2_done)
- return 1;
- 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 (current_program_space->exec_bfd (),
- ".interp");
- if (interp_sect)
- {
- unsigned int interp_sect_size;
- char *buf;
- int status;
- CORE_ADDR addr, interp_loadmap_addr;
- gdb_byte 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 (interp_sect);
- buf = (char *) alloca (interp_sect_size);
- bfd_get_section_contents (current_program_space->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. */
- gdb_bfd_ref_ptr tmp_bfd;
- try
- {
- tmp_bfd = solib_bfd_open (buf);
- }
- catch (const gdb_exception &ex)
- {
- }
- if (tmp_bfd == NULL)
- {
- enable_break_failure_warning ();
- return 0;
- }
- status = frv_fdpic_loadmap_addresses (target_gdbarch (),
- &interp_loadmap_addr, 0);
- if (status < 0)
- {
- warning (_("Unable to determine dynamic linker loadmap address."));
- enable_break_failure_warning ();
- return 0;
- }
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "enable_break: interp_loadmap_addr = %s\n",
- hex_string_custom (interp_loadmap_addr, 8));
- ldm = fetch_loadmap (interp_loadmap_addr);
- if (ldm == NULL)
- {
- warning (_("Unable to load dynamic linker loadmap at address %s."),
- hex_string_custom (interp_loadmap_addr, 8));
- enable_break_failure_warning ();
- 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.get (), ".text");
- if (interp_sect)
- {
- interp_text_sect_low = bfd_section_vma (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 (interp_sect);
- }
- interp_sect = bfd_get_section_by_name (tmp_bfd.get (), ".plt");
- if (interp_sect)
- {
- interp_plt_sect_low = bfd_section_vma (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 (interp_sect);
- }
- addr = gdb_bfd_lookup_symbol (tmp_bfd.get (), cmp_name, "_dl_debug_addr");
- if (addr == 0)
- {
- warning (_("Could not find symbol _dl_debug_addr "
- "in dynamic linker"));
- enable_break_failure_warning ();
- return 0;
- }
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "enable_break: _dl_debug_addr "
- "(prior to relocation) = %s\n",
- hex_string_custom (addr, 8));
- addr += displacement_from_map (ldm, addr);
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "enable_break: _dl_debug_addr "
- "(after relocation) = %s\n",
- hex_string_custom (addr, 8));
- /* 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"),
- hex_string_custom (addr, 8));
- }
- addr = extract_unsigned_integer (addr_buf, sizeof addr_buf, byte_order);
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "enable_break: _dl_debug_addr[0..3] = %s\n",
- hex_string_custom (addr, 8));
- /* If it's zero, then the ldso hasn't initialized yet, and so
- there are no shared libs yet loaded. */
- if (addr == 0)
- {
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "enable_break: ldso not yet initialized\n");
- /* Do not warn, but mark to run again. */
- return 0;
- }
- /* 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"),
- hex_string_custom (addr + 8, 8));
- enable_break_failure_warning ();
- return 0;
- }
- addr = extract_unsigned_integer (addr_buf, sizeof addr_buf, byte_order);
- /* 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"),
- hex_string_custom (addr, 8));
- enable_break_failure_warning ();
- return 0;
- }
- addr = extract_unsigned_integer (addr_buf, sizeof addr_buf, byte_order);
- /* We're done with the loadmap. */
- xfree (ldm);
- /* Remove all the solib event breakpoints. Their addresses
- may have changed since the last time we ran the program. */
- remove_solib_event_breakpoints ();
- /* Now (finally!) create the solib breakpoint. */
- create_solib_event_breakpoint (target_gdbarch (), addr);
- enable_break2_done = 1;
- 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;
- CORE_ADDR entry_point;
- if (current_program_space->symfile_object_file == NULL)
- {
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "enable_break: No symbol file found.\n");
- return 0;
- }
- if (!entry_point_address_query (&entry_point))
- {
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "enable_break: Symbol file has no entry point.\n");
- return 0;
- }
- /* 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 (current_program_space->exec_bfd (),
- ".interp");
- if (interp_sect == NULL)
- {
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "enable_break: No .interp section found.\n");
- return 0;
- }
- create_solib_event_breakpoint (target_gdbarch (), entry_point);
- if (solib_frv_debug)
- gdb_printf (gdb_stdlog,
- "enable_break: solib event breakpoint "
- "placed at entry point: %s\n",
- hex_string_custom (entry_point, 8));
- return 1;
- }
- static void
- frv_relocate_main_executable (void)
- {
- int status;
- CORE_ADDR exec_addr, interp_addr;
- struct int_elf32_fdpic_loadmap *ldm;
- int changed;
- struct obj_section *osect;
- status = frv_fdpic_loadmap_addresses (target_gdbarch (),
- &interp_addr, &exec_addr);
- if (status < 0 || (exec_addr == 0 && interp_addr == 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."));
- delete main_executable_lm_info;
- main_executable_lm_info = new lm_info_frv;
- main_executable_lm_info->map = ldm;
- objfile *objf = current_program_space->symfile_object_file;
- section_offsets new_offsets (objf->section_offsets.size ());
- changed = 0;
- ALL_OBJFILE_OSECTIONS (objf, osect)
- {
- CORE_ADDR orig_addr, addr, offset;
- int osect_idx;
- int seg;
-
- osect_idx = osect - objf->sections;
- /* Current address of section. */
- addr = osect->addr ();
- /* Offset from where this section started. */
- offset = objf->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[osect_idx]
- = ldm->segs[seg].addr - ldm->segs[seg].p_vaddr;
- if (new_offsets[osect_idx] != offset)
- changed = 1;
- break;
- }
- }
- }
- if (changed)
- objfile_relocate (objf, new_offsets);
- /* Now that OBJF has been relocated, we can compute the GOT value
- and stash it away. */
- main_executable_lm_info->got_value = main_got ();
- }
- /* Implement the "create_inferior_hook" target_solib_ops method.
- 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 (int from_tty)
- {
- /* 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_break2_done = 0;
- main_lm_addr = 0;
- delete main_executable_lm_info;
- main_executable_lm_info = NULL;
- }
- static void
- frv_free_so (struct so_list *so)
- {
- lm_info_frv *li = (lm_info_frv *) so->lm_info;
- delete li;
- }
- static void
- frv_relocate_section_addresses (struct so_list *so,
- struct target_section *sec)
- {
- int seg;
- lm_info_frv *li = (lm_info_frv *) so->lm_info;
- int_elf32_fdpic_loadmap *map = li->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 bound_minimal_symbol got_sym;
- objfile *objf = current_program_space->symfile_object_file;
- got_sym = lookup_minimal_symbol ("_GLOBAL_OFFSET_TABLE_", NULL, objf);
- if (got_sym.minsym == 0)
- return 0;
- return BMSYMBOL_VALUE_ADDRESS (got_sym);
- }
- /* Find the global pointer for the given function address ADDR. */
- CORE_ADDR
- frv_fdpic_find_global_pointer (CORE_ADDR addr)
- {
- for (struct so_list *so : current_program_space->solibs ())
- {
- int seg;
- lm_info_frv *li = (lm_info_frv *) so->lm_info;
- int_elf32_fdpic_loadmap *map = li->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 li->got_value;
- }
- }
- /* Didn't find it in 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, const char *, bfd *, lm_info_frv *);
- /* 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)
- {
- const char *name;
- CORE_ADDR addr;
- CORE_ADDR got_value;
- struct symbol *sym;
- /* 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 = sym->linkage_name ();
- /* Check the main executable. */
- objfile *objf = current_program_space->symfile_object_file;
- addr = find_canonical_descriptor_in_load_object
- (entry_point, got_value, name, objf->obfd,
- main_executable_lm_info);
- /* If descriptor not found via main executable, check each load object
- in list of shared objects. */
- if (addr == 0)
- {
- for (struct so_list *so : current_program_space->solibs ())
- {
- lm_info_frv *li = (lm_info_frv *) so->lm_info;
- addr = find_canonical_descriptor_in_load_object
- (entry_point, got_value, name, so->abfd, li);
- if (addr != 0)
- break;
- }
- }
- return addr;
- }
- static CORE_ADDR
- find_canonical_descriptor_in_load_object
- (CORE_ADDR entry_point, CORE_ADDR got_value, const char *name, bfd *abfd,
- lm_info_frv *lm)
- {
- enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
- arelent *rel;
- unsigned int i;
- CORE_ADDR addr = 0;
- /* Nothing to do if no bfd. */
- if (abfd == 0)
- return 0;
- /* Nothing to do if no link map. */
- if (lm == 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)
- {
- gdb_byte 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, byte_order);
- /* Check for matching entry point. */
- if (target_read_memory (addr, buf, sizeof buf) != 0)
- continue;
- if (extract_unsigned_integer (buf, sizeof buf, byte_order)
- != 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, byte_order)
- != got_value)
- continue;
- /* Match was successful! Exit loop. */
- break;
- }
- }
- return addr;
- }
- /* Given an objfile, return the address of its link map. This value is
- needed for TLS support. */
- CORE_ADDR
- frv_fetch_objfile_link_map (struct objfile *objfile)
- {
- /* Cause frv_current_sos() to be run if it hasn't been already. */
- if (main_lm_addr == 0)
- solib_add (0, 0, 1);
- /* frv_current_sos() will set main_lm_addr for the main executable. */
- if (objfile == current_program_space->symfile_object_file)
- return main_lm_addr;
- /* The other link map addresses may be found by examining the list
- of shared libraries. */
- for (struct so_list *so : current_program_space->solibs ())
- {
- lm_info_frv *li = (lm_info_frv *) so->lm_info;
- if (so->objfile == objfile)
- return li->lm_addr;
- }
- /* Not found! */
- return 0;
- }
- struct target_so_ops frv_so_ops;
- void _initialize_frv_solib ();
- void
- _initialize_frv_solib ()
- {
- 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.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;
- frv_so_ops.bfd_open = solib_bfd_open;
- /* Debug this file's internals. */
- add_setshow_zuinteger_cmd ("solib-frv", class_maintenance,
- &solib_frv_debug, _("\
- Set internal debugging of shared library code for FR-V."), _("\
- Show internal debugging of shared library code for FR-V."), _("\
- When non-zero, FR-V solib specific internal debugging is enabled."),
- NULL,
- NULL, /* FIXME: i18n: */
- &setdebuglist, &showdebuglist);
- }
|