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- /* Frame unwinder for ia64 frames using the libunwind library.
- Copyright (C) 2003-2022 Free Software Foundation, Inc.
- Written by Jeff Johnston, contributed by Red Hat 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 "frame.h"
- #include "frame-base.h"
- #include "frame-unwind.h"
- #include "gdbcore.h"
- #include "gdbtypes.h"
- #include "symtab.h"
- #include "objfiles.h"
- #include "regcache.h"
- #include <dlfcn.h>
- #include "ia64-libunwind-tdep.h"
- #include "gdbsupport/preprocessor.h"
- /* IA-64 is the only target that currently uses ia64-libunwind-tdep.
- Note how UNW_TARGET, UNW_OBJ, etc. are compile time constants below.
- Those come from libunwind's headers, and are target dependent.
- Also, some of libunwind's typedefs are target dependent, as e.g.,
- unw_word_t. If some other target wants to use this, we will need
- to do some abstracting in order to make it possible to select which
- libunwind we're talking to at runtime (and have one per arch). */
- /* The following two macros are normally defined in <endian.h>.
- But systems such as ia64-hpux do not provide such header, so
- we just define them here if not already defined. */
- #ifndef __LITTLE_ENDIAN
- #define __LITTLE_ENDIAN 1234
- #endif
- #ifndef __BIG_ENDIAN
- #define __BIG_ENDIAN 4321
- #endif
- static int libunwind_initialized;
- static struct gdbarch_data *libunwind_descr_handle;
- /* Required function pointers from libunwind. */
- typedef int (unw_get_reg_p_ftype) (unw_cursor_t *, unw_regnum_t, unw_word_t *);
- static unw_get_reg_p_ftype *unw_get_reg_p;
- typedef int (unw_get_fpreg_p_ftype) (unw_cursor_t *, unw_regnum_t,
- unw_fpreg_t *);
- static unw_get_fpreg_p_ftype *unw_get_fpreg_p;
- typedef int (unw_get_saveloc_p_ftype) (unw_cursor_t *, unw_regnum_t,
- unw_save_loc_t *);
- static unw_get_saveloc_p_ftype *unw_get_saveloc_p;
- typedef int (unw_is_signal_frame_p_ftype) (unw_cursor_t *);
- static unw_is_signal_frame_p_ftype *unw_is_signal_frame_p;
- typedef int (unw_step_p_ftype) (unw_cursor_t *);
- static unw_step_p_ftype *unw_step_p;
- typedef int (unw_init_remote_p_ftype) (unw_cursor_t *, unw_addr_space_t,
- void *);
- static unw_init_remote_p_ftype *unw_init_remote_p;
- typedef unw_addr_space_t (unw_create_addr_space_p_ftype) (unw_accessors_t *,
- int);
- static unw_create_addr_space_p_ftype *unw_create_addr_space_p;
- typedef void (unw_destroy_addr_space_p_ftype) (unw_addr_space_t);
- static unw_destroy_addr_space_p_ftype *unw_destroy_addr_space_p;
- typedef int (unw_search_unwind_table_p_ftype) (unw_addr_space_t, unw_word_t,
- unw_dyn_info_t *,
- unw_proc_info_t *, int, void *);
- static unw_search_unwind_table_p_ftype *unw_search_unwind_table_p;
- typedef unw_word_t (unw_find_dyn_list_p_ftype) (unw_addr_space_t,
- unw_dyn_info_t *, void *);
- static unw_find_dyn_list_p_ftype *unw_find_dyn_list_p;
- struct libunwind_frame_cache
- {
- CORE_ADDR base;
- CORE_ADDR func_addr;
- unw_cursor_t cursor;
- unw_addr_space_t as;
- };
- /* We need to qualify the function names with a platform-specific prefix
- to match the names used by the libunwind library. The UNW_OBJ macro is
- provided by the libunwind.h header file. */
- #ifndef LIBUNWIND_SO
- /* Use the stable ABI major version number. `libunwind-ia64.so' is a link time
- only library, not a runtime one. */
- #define LIBUNWIND_SO "libunwind-" STRINGIFY(UNW_TARGET) ".so.8"
- /* Provide also compatibility with older .so. The two APIs are compatible, .8
- is only extended a bit, GDB does not use the extended API at all. */
- #define LIBUNWIND_SO_7 "libunwind-" STRINGIFY(UNW_TARGET) ".so.7"
- #endif
- static const char *get_reg_name = STRINGIFY(UNW_OBJ(get_reg));
- static const char *get_fpreg_name = STRINGIFY(UNW_OBJ(get_fpreg));
- static const char *get_saveloc_name = STRINGIFY(UNW_OBJ(get_save_loc));
- static const char *is_signal_frame_name = STRINGIFY(UNW_OBJ(is_signal_frame));
- static const char *step_name = STRINGIFY(UNW_OBJ(step));
- static const char *init_remote_name = STRINGIFY(UNW_OBJ(init_remote));
- static const char *create_addr_space_name
- = STRINGIFY(UNW_OBJ(create_addr_space));
- static const char *destroy_addr_space_name
- = STRINGIFY(UNW_OBJ(destroy_addr_space));
- static const char *search_unwind_table_name
- = STRINGIFY(UNW_OBJ(search_unwind_table));
- static const char *find_dyn_list_name = STRINGIFY(UNW_OBJ(find_dyn_list));
- static struct libunwind_descr *
- libunwind_descr (struct gdbarch *gdbarch)
- {
- return ((struct libunwind_descr *)
- gdbarch_data (gdbarch, libunwind_descr_handle));
- }
- static void *
- libunwind_descr_init (struct obstack *obstack)
- {
- struct libunwind_descr *descr
- = OBSTACK_ZALLOC (obstack, struct libunwind_descr);
- return descr;
- }
- void
- libunwind_frame_set_descr (struct gdbarch *gdbarch,
- struct libunwind_descr *descr)
- {
- struct libunwind_descr *arch_descr;
- gdb_assert (gdbarch != NULL);
- arch_descr = ((struct libunwind_descr *)
- gdbarch_data (gdbarch, libunwind_descr_handle));
- gdb_assert (arch_descr != NULL);
- /* Copy new descriptor info into arch descriptor. */
- arch_descr->gdb2uw = descr->gdb2uw;
- arch_descr->uw2gdb = descr->uw2gdb;
- arch_descr->is_fpreg = descr->is_fpreg;
- arch_descr->accessors = descr->accessors;
- arch_descr->special_accessors = descr->special_accessors;
- }
- static struct libunwind_frame_cache *
- libunwind_frame_cache (struct frame_info *this_frame, void **this_cache)
- {
- unw_accessors_t *acc;
- unw_addr_space_t as;
- unw_word_t fp;
- unw_regnum_t uw_sp_regnum;
- struct libunwind_frame_cache *cache;
- struct libunwind_descr *descr;
- struct gdbarch *gdbarch = get_frame_arch (this_frame);
- int ret;
- if (*this_cache)
- return (struct libunwind_frame_cache *) *this_cache;
- /* Allocate a new cache. */
- cache = FRAME_OBSTACK_ZALLOC (struct libunwind_frame_cache);
- cache->func_addr = get_frame_func (this_frame);
- if (cache->func_addr == 0)
- /* This can happen when the frame corresponds to a function for which
- there is no debugging information nor any entry in the symbol table.
- This is probably a static function for which an entry in the symbol
- table was not created when the objfile got linked (observed in
- libpthread.so on ia64-hpux).
- The best we can do, in that case, is use the frame PC as the function
- address. We don't need to give up since we still have the unwind
- record to help us perform the unwinding. There is also another
- compelling to continue, because abandoning now means stopping
- the backtrace, which can never be helpful for the user. */
- cache->func_addr = get_frame_pc (this_frame);
- /* Get a libunwind cursor to the previous frame.
-
- We do this by initializing a cursor. Libunwind treats a new cursor
- as the top of stack and will get the current register set via the
- libunwind register accessor. Now, we provide the platform-specific
- accessors and we set up the register accessor to use the frame
- register unwinding interfaces so that we properly get the registers
- for the current frame rather than the top. We then use the unw_step
- function to move the libunwind cursor back one frame. We can later
- use this cursor to find previous registers via the unw_get_reg
- interface which will invoke libunwind's special logic. */
- descr = libunwind_descr (gdbarch);
- acc = (unw_accessors_t *) descr->accessors;
- as = unw_create_addr_space_p (acc,
- gdbarch_byte_order (gdbarch)
- == BFD_ENDIAN_BIG
- ? __BIG_ENDIAN
- : __LITTLE_ENDIAN);
- unw_init_remote_p (&cache->cursor, as, this_frame);
- if (unw_step_p (&cache->cursor) < 0)
- {
- unw_destroy_addr_space_p (as);
- return NULL;
- }
- /* To get base address, get sp from previous frame. */
- uw_sp_regnum = descr->gdb2uw (gdbarch_sp_regnum (gdbarch));
- ret = unw_get_reg_p (&cache->cursor, uw_sp_regnum, &fp);
- if (ret < 0)
- {
- unw_destroy_addr_space_p (as);
- error (_("Can't get libunwind sp register."));
- }
- cache->base = (CORE_ADDR)fp;
- cache->as = as;
- *this_cache = cache;
- return cache;
- }
- void
- libunwind_frame_dealloc_cache (struct frame_info *self, void *this_cache)
- {
- struct libunwind_frame_cache *cache
- = (struct libunwind_frame_cache *) this_cache;
- if (cache->as)
- unw_destroy_addr_space_p (cache->as);
- }
- unw_word_t
- libunwind_find_dyn_list (unw_addr_space_t as, unw_dyn_info_t *di, void *arg)
- {
- return unw_find_dyn_list_p (as, di, arg);
- }
- /* Verify if there is sufficient libunwind information for the frame to use
- libunwind frame unwinding. */
- int
- libunwind_frame_sniffer (const struct frame_unwind *self,
- struct frame_info *this_frame, void **this_cache)
- {
- unw_cursor_t cursor;
- unw_accessors_t *acc;
- unw_addr_space_t as;
- struct libunwind_descr *descr;
- struct gdbarch *gdbarch = get_frame_arch (this_frame);
- int ret;
- /* To test for libunwind unwind support, initialize a cursor to
- the current frame and try to back up. We use this same method
- when setting up the frame cache (see libunwind_frame_cache()).
- If libunwind returns success for this operation, it means that
- it has found sufficient libunwind unwinding information to do so. */
- descr = libunwind_descr (gdbarch);
- acc = (unw_accessors_t *) descr->accessors;
- as = unw_create_addr_space_p (acc,
- gdbarch_byte_order (gdbarch)
- == BFD_ENDIAN_BIG
- ? __BIG_ENDIAN
- : __LITTLE_ENDIAN);
- ret = unw_init_remote_p (&cursor, as, this_frame);
- if (ret < 0)
- {
- unw_destroy_addr_space_p (as);
- return 0;
- }
-
- /* Check to see if we have libunwind info by checking if we are in a
- signal frame. If it doesn't return an error, we have libunwind info
- and can use libunwind. */
- ret = unw_is_signal_frame_p (&cursor);
- unw_destroy_addr_space_p (as);
- if (ret < 0)
- return 0;
- return 1;
- }
- void
- libunwind_frame_this_id (struct frame_info *this_frame, void **this_cache,
- struct frame_id *this_id)
- {
- struct libunwind_frame_cache *cache =
- libunwind_frame_cache (this_frame, this_cache);
- if (cache != NULL)
- (*this_id) = frame_id_build (cache->base, cache->func_addr);
- }
- struct value *
- libunwind_frame_prev_register (struct frame_info *this_frame,
- void **this_cache, int regnum)
- {
- struct libunwind_frame_cache *cache =
- libunwind_frame_cache (this_frame, this_cache);
- unw_save_loc_t sl;
- int ret;
- unw_word_t intval;
- unw_fpreg_t fpval;
- unw_regnum_t uw_regnum;
- struct libunwind_descr *descr;
- struct value *val = NULL;
- if (cache == NULL)
- return frame_unwind_got_constant (this_frame, regnum, 0);
-
- /* Convert from gdb register number to libunwind register number. */
- descr = libunwind_descr (get_frame_arch (this_frame));
- uw_regnum = descr->gdb2uw (regnum);
- gdb_assert (regnum >= 0);
- if (!target_has_registers ())
- error (_("No registers."));
- if (uw_regnum < 0)
- return frame_unwind_got_constant (this_frame, regnum, 0);
- if (unw_get_saveloc_p (&cache->cursor, uw_regnum, &sl) < 0)
- return frame_unwind_got_constant (this_frame, regnum, 0);
- switch (sl.type)
- {
- case UNW_SLT_MEMORY:
- val = frame_unwind_got_memory (this_frame, regnum, sl.u.addr);
- break;
- case UNW_SLT_REG:
- val = frame_unwind_got_register (this_frame, regnum,
- descr->uw2gdb (sl.u.regnum));
- break;
- case UNW_SLT_NONE:
- {
- /* The register is not stored at a specific memory address nor
- inside another register. So use libunwind to fetch the register
- value for us, and create a constant value with the result. */
- if (descr->is_fpreg (uw_regnum))
- {
- ret = unw_get_fpreg_p (&cache->cursor, uw_regnum, &fpval);
- if (ret < 0)
- return frame_unwind_got_constant (this_frame, regnum, 0);
- val = frame_unwind_got_bytes (this_frame, regnum,
- (gdb_byte *) &fpval);
- }
- else
- {
- ret = unw_get_reg_p (&cache->cursor, uw_regnum, &intval);
- if (ret < 0)
- return frame_unwind_got_constant (this_frame, regnum, 0);
- val = frame_unwind_got_constant (this_frame, regnum, intval);
- }
- break;
- }
- }
- return val;
- }
- /* The following is a glue routine to call the libunwind unwind table
- search function to get unwind information for a specified ip address. */
- int
- libunwind_search_unwind_table (void *as, long ip, void *di,
- void *pi, int need_unwind_info, void *args)
- {
- return unw_search_unwind_table_p (*(unw_addr_space_t *) as, (unw_word_t) ip,
- (unw_dyn_info_t *) di,
- (unw_proc_info_t *) pi, need_unwind_info,
- args);
- }
- /* Verify if we are in a sigtramp frame and we can use libunwind to unwind. */
- int
- libunwind_sigtramp_frame_sniffer (const struct frame_unwind *self,
- struct frame_info *this_frame,
- void **this_cache)
- {
- unw_cursor_t cursor;
- unw_accessors_t *acc;
- unw_addr_space_t as;
- struct libunwind_descr *descr;
- struct gdbarch *gdbarch = get_frame_arch (this_frame);
- int ret;
- /* To test for libunwind unwind support, initialize a cursor to the
- current frame and try to back up. We use this same method when
- setting up the frame cache (see libunwind_frame_cache()). If
- libunwind returns success for this operation, it means that it
- has found sufficient libunwind unwinding information to do
- so. */
- descr = libunwind_descr (gdbarch);
- acc = (unw_accessors_t *) descr->accessors;
- as = unw_create_addr_space_p (acc,
- gdbarch_byte_order (gdbarch)
- == BFD_ENDIAN_BIG
- ? __BIG_ENDIAN
- : __LITTLE_ENDIAN);
- ret = unw_init_remote_p (&cursor, as, this_frame);
- if (ret < 0)
- {
- unw_destroy_addr_space_p (as);
- return 0;
- }
- /* Check to see if we are in a signal frame. */
- ret = unw_is_signal_frame_p (&cursor);
- unw_destroy_addr_space_p (as);
- if (ret > 0)
- return 1;
- return 0;
- }
- /* The following routine is for accessing special registers of the top frame.
- A special set of accessors must be given that work without frame info.
- This is used by ia64 to access the rse registers r32-r127. While they
- are usually located at BOF, this is not always true and only the libunwind
- info can decipher where they actually are. */
- int
- libunwind_get_reg_special (struct gdbarch *gdbarch, readable_regcache *regcache,
- int regnum, void *buf)
- {
- unw_cursor_t cursor;
- unw_accessors_t *acc;
- unw_addr_space_t as;
- struct libunwind_descr *descr;
- int ret;
- unw_regnum_t uw_regnum;
- unw_word_t intval;
- unw_fpreg_t fpval;
- void *ptr;
- descr = libunwind_descr (gdbarch);
- acc = (unw_accessors_t *) descr->special_accessors;
- as = unw_create_addr_space_p (acc,
- gdbarch_byte_order (gdbarch)
- == BFD_ENDIAN_BIG
- ? __BIG_ENDIAN
- : __LITTLE_ENDIAN);
- ret = unw_init_remote_p (&cursor, as, regcache);
- if (ret < 0)
- {
- unw_destroy_addr_space_p (as);
- return -1;
- }
- uw_regnum = descr->gdb2uw (regnum);
- if (descr->is_fpreg (uw_regnum))
- {
- ret = unw_get_fpreg_p (&cursor, uw_regnum, &fpval);
- ptr = &fpval;
- }
- else
- {
- ret = unw_get_reg_p (&cursor, uw_regnum, &intval);
- ptr = &intval;
- }
- unw_destroy_addr_space_p (as);
- if (ret < 0)
- return -1;
- if (buf)
- memcpy (buf, ptr, register_size (gdbarch, regnum));
- return 0;
- }
-
- static int
- libunwind_load (void)
- {
- void *handle;
- char *so_error = NULL;
- handle = dlopen (LIBUNWIND_SO, RTLD_NOW);
- if (handle == NULL)
- {
- so_error = xstrdup (dlerror ());
- #ifdef LIBUNWIND_SO_7
- handle = dlopen (LIBUNWIND_SO_7, RTLD_NOW);
- #endif /* LIBUNWIND_SO_7 */
- }
- if (handle == NULL)
- {
- gdb_printf (gdb_stderr, _("[GDB failed to load %s: %s]\n"),
- LIBUNWIND_SO, so_error);
- #ifdef LIBUNWIND_SO_7
- gdb_printf (gdb_stderr, _("[GDB failed to load %s: %s]\n"),
- LIBUNWIND_SO_7, dlerror ());
- #endif /* LIBUNWIND_SO_7 */
- }
- xfree (so_error);
- if (handle == NULL)
- return 0;
- /* Initialize pointers to the dynamic library functions we will use. */
- unw_get_reg_p = (unw_get_reg_p_ftype *) dlsym (handle, get_reg_name);
- if (unw_get_reg_p == NULL)
- return 0;
- unw_get_fpreg_p = (unw_get_fpreg_p_ftype *) dlsym (handle, get_fpreg_name);
- if (unw_get_fpreg_p == NULL)
- return 0;
- unw_get_saveloc_p
- = (unw_get_saveloc_p_ftype *) dlsym (handle, get_saveloc_name);
- if (unw_get_saveloc_p == NULL)
- return 0;
- unw_is_signal_frame_p
- = (unw_is_signal_frame_p_ftype *) dlsym (handle, is_signal_frame_name);
- if (unw_is_signal_frame_p == NULL)
- return 0;
- unw_step_p = (unw_step_p_ftype *) dlsym (handle, step_name);
- if (unw_step_p == NULL)
- return 0;
- unw_init_remote_p
- = (unw_init_remote_p_ftype *) dlsym (handle, init_remote_name);
- if (unw_init_remote_p == NULL)
- return 0;
- unw_create_addr_space_p
- = (unw_create_addr_space_p_ftype *) dlsym (handle, create_addr_space_name);
- if (unw_create_addr_space_p == NULL)
- return 0;
- unw_destroy_addr_space_p
- = (unw_destroy_addr_space_p_ftype *) dlsym (handle,
- destroy_addr_space_name);
- if (unw_destroy_addr_space_p == NULL)
- return 0;
- unw_search_unwind_table_p
- = (unw_search_unwind_table_p_ftype *) dlsym (handle,
- search_unwind_table_name);
- if (unw_search_unwind_table_p == NULL)
- return 0;
- unw_find_dyn_list_p
- = (unw_find_dyn_list_p_ftype *) dlsym (handle, find_dyn_list_name);
- if (unw_find_dyn_list_p == NULL)
- return 0;
-
- return 1;
- }
- int
- libunwind_is_initialized (void)
- {
- return libunwind_initialized;
- }
- void _initialize_libunwind_frame ();
- void
- _initialize_libunwind_frame ()
- {
- libunwind_descr_handle
- = gdbarch_data_register_pre_init (libunwind_descr_init);
- libunwind_initialized = libunwind_load ();
- }
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