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Diffstat (limited to 'gdb/solib-spu.c')
| -rw-r--r-- | gdb/solib-spu.c | 455 |
1 files changed, 455 insertions, 0 deletions
diff --git a/gdb/solib-spu.c b/gdb/solib-spu.c new file mode 100644 index 0000000..19e3212 --- /dev/null +++ b/gdb/solib-spu.c @@ -0,0 +1,455 @@ +/* Cell SPU GNU/Linux support -- shared library handling. + Copyright (C) 2009 Free Software Foundation, Inc. + + Contributed by Ulrich Weigand <uweigand@de.ibm.com>. + + 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 "gdbcore.h" +#include "gdb_string.h" +#include "gdb_assert.h" +#include "gdb_stat.h" +#include "arch-utils.h" +#include "bfd.h" +#include "symtab.h" +#include "solib.h" +#include "solib-svr4.h" +#include "solist.h" +#include "inferior.h" +#include "objfiles.h" +#include "observer.h" +#include "breakpoint.h" +#include "gdbthread.h" + +#include "spu-tdep.h" + +/* Highest SPE id (file handle) the inferior may have. */ +#define MAX_SPE_FD 1024 + +/* Stand-alone SPE executable? */ +#define spu_standalone_p() \ + (symfile_objfile && symfile_objfile->obfd \ + && bfd_get_arch (symfile_objfile->obfd) == bfd_arch_spu) + + +/* Relocate main SPE executable. */ +static void +spu_relocate_main_executable (int spufs_fd) +{ + struct objfile *objfile; + struct cleanup *old_chain; + struct section_offsets *new_offsets; + int i; + + for (objfile = symfile_objfile; + objfile; + objfile = objfile->separate_debug_objfile) + { + new_offsets = xcalloc (objfile->num_sections, + sizeof (struct section_offsets)); + old_chain = make_cleanup (xfree, new_offsets); + + for (i = 0; i < objfile->num_sections; i++) + new_offsets->offsets[i] = SPUADDR (spufs_fd, 0); + + objfile_relocate (objfile, new_offsets); + do_cleanups (old_chain); + } +} + +/* When running a stand-alone SPE executable, we may need to skip one more + exec event on startup, to get past the binfmt_misc loader. */ +static void +spu_skip_standalone_loader (void) +{ + if (target_has_execution && !current_inferior ()->attach_flag) + { + struct target_waitstatus ws; + + /* Only some kernels report an extra SIGTRAP with the binfmt_misc + loader; others do not. In addition, if we have attached to an + already running inferior instead of starting a new one, we will + not see the extra SIGTRAP -- and we cannot readily distinguish + the two cases, in particular with the extended-remote target. + + Thus we issue a single-step here. If no extra SIGTRAP was pending, + this will step past the first instruction of the stand-alone SPE + executable loader, but we don't care about that. */ + + inferior_thread ()->in_infcall = 1; /* Suppress MI messages. */ + + target_resume (inferior_ptid, 1, TARGET_SIGNAL_0); + target_wait (minus_one_ptid, &ws, 0); + set_executing (minus_one_ptid, 0); + + inferior_thread ()->in_infcall = 0; + } +} + +/* Build a list of `struct so_list' objects describing the shared + objects currently loaded in the inferior. */ +static struct so_list * +spu_current_sos (void) +{ + enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch); + struct so_list *head; + struct so_list **link_ptr; + + char buf[MAX_SPE_FD * 4]; + int i, size; + + /* First, retrieve the SVR4 shared library list. */ + head = svr4_so_ops.current_sos (); + + /* Append our libraries to the end of the list. */ + for (link_ptr = &head; *link_ptr; link_ptr = &(*link_ptr)->next) + ; + + /* Determine list of SPU ids. */ + size = target_read (¤t_target, TARGET_OBJECT_SPU, NULL, + buf, 0, sizeof buf); + + /* Do not add stand-alone SPE executable context as shared library, + but relocate main SPE executable objfile. */ + if (spu_standalone_p ()) + { + if (size == 4) + { + int fd = extract_unsigned_integer (buf, 4, byte_order); + spu_relocate_main_executable (fd); + + /* Re-enable breakpoints after main SPU context was established; + see also comments in spu_solib_create_inferior_hook. */ + enable_breakpoints_after_startup (); + } + + return head; + } + + /* Create an so_list entry for each SPU id. */ + for (i = 0; i < size; i += 4) + { + int fd = extract_unsigned_integer (buf + i, 4, byte_order); + struct so_list *new; + + unsigned long long addr; + char annex[32], id[100]; + int len; + + /* Read object ID. There's a race window where the inferior may have + already created the SPE context, but not installed the object-id + yet. Skip such entries; we'll be back for them later. */ + xsnprintf (annex, sizeof annex, "%d/object-id", fd); + len = target_read (¤t_target, TARGET_OBJECT_SPU, annex, + id, 0, sizeof id); + if (len <= 0 || len >= sizeof id) + continue; + id[len] = 0; + if (sscanf (id, "0x%llx", &addr) != 1 || !addr) + continue; + + /* Allocate so_list structure. */ + new = XZALLOC (struct so_list); + + /* Encode FD and object ID in path name. Choose the name so as not + to conflict with any (normal) SVR4 library path name. */ + xsnprintf (new->so_name, sizeof new->so_name, "@0x%llx <%d>", addr, fd); + strcpy (new->so_original_name, new->so_name); + + *link_ptr = new; + link_ptr = &new->next; + } + + return head; +} + +/* Free so_list information. */ +static void +spu_free_so (struct so_list *so) +{ + if (so->so_original_name[0] != '@') + svr4_so_ops.free_so (so); +} + +/* Relocate section addresses. */ +static void +spu_relocate_section_addresses (struct so_list *so, + struct target_section *sec) +{ + if (so->so_original_name[0] != '@') + svr4_so_ops.relocate_section_addresses (so, sec); + else + { + unsigned long long addr; + int fd; + + /* Set addr_low/high to just LS offset for display. */ + if (so->addr_low == 0 && so->addr_high == 0 + && strcmp (sec->the_bfd_section->name, ".text") == 0) + { + so->addr_low = sec->addr; + so->addr_high = sec->endaddr; + } + + /* Decode object ID. */ + if (sscanf (so->so_original_name, "@0x%llx <%d>", &addr, &fd) != 2) + internal_error (__FILE__, __LINE__, "bad object ID"); + + sec->addr = SPUADDR (fd, sec->addr); + sec->endaddr = SPUADDR (fd, sec->endaddr); + } +} + + +/* Inferior memory should contain an SPE executable image at location ADDR. + Allocate a BFD representing that executable. Return NULL on error. */ + +static void * +spu_bfd_iovec_open (bfd *nbfd, void *open_closure) +{ + return open_closure; +} + +static int +spu_bfd_iovec_close (bfd *nbfd, void *stream) +{ + xfree (stream); + return 1; +} + +static file_ptr +spu_bfd_iovec_pread (bfd *abfd, void *stream, void *buf, + file_ptr nbytes, file_ptr offset) +{ + CORE_ADDR addr = *(CORE_ADDR *)stream; + int ret; + + ret = target_read_memory (addr + offset, buf, nbytes); + if (ret != 0) + { + bfd_set_error (bfd_error_invalid_operation); + return -1; + } + + return nbytes; +} + +static int +spu_bfd_iovec_stat (bfd *abfd, void *stream, struct stat *sb) +{ + /* We don't have an easy way of finding the size of embedded spu + images. We could parse the in-memory ELF header and section + table to find the extent of the last section but that seems + pointless when the size is needed only for checks of other + parsed values in dbxread.c. */ + sb->st_size = INT_MAX; + return 0; +} + +static bfd * +spu_bfd_fopen (char *name, CORE_ADDR addr) +{ + bfd *nbfd; + + CORE_ADDR *open_closure = xmalloc (sizeof (CORE_ADDR)); + *open_closure = addr; + + nbfd = bfd_openr_iovec (xstrdup (name), "elf32-spu", + spu_bfd_iovec_open, open_closure, + spu_bfd_iovec_pread, spu_bfd_iovec_close, + spu_bfd_iovec_stat); + if (!nbfd) + return NULL; + + if (!bfd_check_format (nbfd, bfd_object)) + { + bfd_close (nbfd); + return NULL; + } + + return nbfd; +} + +/* Open shared library BFD. */ +static bfd * +spu_bfd_open (char *pathname) +{ + char *original_name = strrchr (pathname, '@'); + bfd *abfd; + asection *spu_name; + unsigned long long addr; + int fd; + + /* Handle regular SVR4 libraries. */ + if (!original_name) + return svr4_so_ops.bfd_open (pathname); + + /* Decode object ID. */ + if (sscanf (original_name, "@0x%llx <%d>", &addr, &fd) != 2) + internal_error (__FILE__, __LINE__, "bad object ID"); + + /* Open BFD representing SPE executable. */ + abfd = spu_bfd_fopen (original_name, (CORE_ADDR) addr); + if (!abfd) + error (_("Cannot read SPE executable at %s"), original_name); + + /* Retrieve SPU name note. */ + spu_name = bfd_get_section_by_name (abfd, ".note.spu_name"); + if (spu_name) + { + int sect_size = bfd_section_size (abfd, spu_name); + if (sect_size > 20) + { + char *buf = alloca (sect_size - 20 + strlen (original_name) + 1); + bfd_get_section_contents (abfd, spu_name, buf, 20, sect_size - 20); + buf[sect_size - 20] = '\0'; + + strcat (buf, original_name); + + xfree ((char *)abfd->filename); + abfd->filename = xstrdup (buf); + } + } + + return abfd; +} + +/* Lookup global symbol in a SPE executable. */ +static struct symbol * +spu_lookup_lib_symbol (const struct objfile *objfile, + const char *name, + const char *linkage_name, + const domain_enum domain) +{ + if (bfd_get_arch (objfile->obfd) == bfd_arch_spu) + return lookup_global_symbol_from_objfile (objfile, name, linkage_name, + domain); + + if (svr4_so_ops.lookup_lib_global_symbol != NULL) + return svr4_so_ops.lookup_lib_global_symbol (objfile, name, linkage_name, + domain); + return NULL; +} + +/* Enable shared library breakpoint. */ +static int +spu_enable_break (struct objfile *objfile) +{ + struct minimal_symbol *spe_event_sym = NULL; + + /* The libspe library will call __spe_context_update_event whenever any + SPE context is allocated or destroyed. */ + spe_event_sym = lookup_minimal_symbol ("__spe_context_update_event", + NULL, objfile); + + /* Place a solib_event breakpoint on the symbol. */ + if (spe_event_sym) + { + CORE_ADDR addr = SYMBOL_VALUE_ADDRESS (spe_event_sym); + addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch, addr, + ¤t_target); + create_solib_event_breakpoint (target_gdbarch, addr); + return 1; + } + + return 0; +} + +/* Create inferior hook. */ +static void +spu_solib_create_inferior_hook (void) +{ + /* Remove all previously installed solib breakpoints. Both the SVR4 + code and us will re-install all required breakpoints. */ + remove_solib_event_breakpoints (); + + /* Handle SPE stand-alone executables. */ + if (spu_standalone_p ()) + { + /* After an SPE stand-alone executable was loaded, we'll receive + an additional trap due to the binfmt_misc handler. Make sure + to skip that trap. */ + spu_skip_standalone_loader (); + + /* If the user established breakpoints before starting the inferior, GDB + would attempt to insert those now. This would fail because the SPU + context has not yet been created and the SPU executable has not yet + been loaded. To prevent such failures, we disable all user-created + breakpoints now; they will be re-enabled in spu_current_sos once the + main SPU context has been detected. */ + disable_breakpoints_before_startup (); + + /* A special case arises when re-starting an executable, because at + this point it still resides at the relocated address range that was + determined during its last execution. We need to undo the relocation + so that that multi-architecture target recognizes the stand-alone + initialization special case. */ + spu_relocate_main_executable (-1); + } + + /* Call SVR4 hook -- this will re-insert the SVR4 solib breakpoints. */ + svr4_so_ops.solib_create_inferior_hook (); + + /* If the inferior is statically linked against libspe, we need to install + our own solib breakpoint right now. Otherwise, it will be installed by + the solib_loaded observer below as soon as libspe is loaded. */ + spu_enable_break (NULL); +} + +/* Install SPE "shared library" handling. This is called by -tdep code + that wants to support SPU as a secondary architecture. */ +void +set_spu_solib_ops (struct gdbarch *gdbarch) +{ + static struct target_so_ops spu_so_ops; + + /* Initialize this lazily, to avoid an initialization order + dependency on solib-svr4.c's _initialize routine. */ + if (spu_so_ops.current_sos == NULL) + { + spu_so_ops = svr4_so_ops; + spu_so_ops.solib_create_inferior_hook = spu_solib_create_inferior_hook; + spu_so_ops.relocate_section_addresses = spu_relocate_section_addresses; + spu_so_ops.free_so = spu_free_so; + spu_so_ops.current_sos = spu_current_sos; + spu_so_ops.bfd_open = spu_bfd_open; + spu_so_ops.lookup_lib_global_symbol = spu_lookup_lib_symbol; + } + + set_solib_ops (gdbarch, &spu_so_ops); +} + +/* Observer for the solib_loaded event. Used to install our breakpoint + if libspe is a shared library. */ +static void +spu_solib_loaded (struct so_list *so) +{ + if (strstr (so->so_original_name, "/libspe") != NULL) + { + solib_read_symbols (so, so->from_tty ? SYMFILE_VERBOSE : 0); + spu_enable_break (so->objfile); + } +} + +void +_initialize_spu_solib (void) +{ + observer_attach_solib_loaded (spu_solib_loaded); +} + |