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Diffstat (limited to 'gdb/ia64-libunwind-tdep.c')
| -rw-r--r-- | gdb/ia64-libunwind-tdep.c | 582 |
1 files changed, 582 insertions, 0 deletions
diff --git a/gdb/ia64-libunwind-tdep.c b/gdb/ia64-libunwind-tdep.c new file mode 100644 index 0000000..e1c89c4 --- /dev/null +++ b/gdb/ia64-libunwind-tdep.c @@ -0,0 +1,582 @@ +/* Frame unwinder for ia64 frames using the libunwind library. + + Copyright (C) 2003-2004, 2006-2012 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 "gdb_assert.h" +#include "gdb_string.h" + +#include "ia64-libunwind-tdep.h" + +#include "complaints.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. */ +static int (*unw_get_reg_p) (unw_cursor_t *, unw_regnum_t, unw_word_t *); +static int (*unw_get_fpreg_p) (unw_cursor_t *, unw_regnum_t, unw_fpreg_t *); +static int (*unw_get_saveloc_p) (unw_cursor_t *, unw_regnum_t, + unw_save_loc_t *); +static int (*unw_is_signal_frame_p) (unw_cursor_t *); +static int (*unw_step_p) (unw_cursor_t *); +static int (*unw_init_remote_p) (unw_cursor_t *, unw_addr_space_t, void *); +static unw_addr_space_t (*unw_create_addr_space_p) (unw_accessors_t *, int); +static void (*unw_destroy_addr_space_p) (unw_addr_space_t); +static int (*unw_search_unwind_table_p) (unw_addr_space_t, unw_word_t, + unw_dyn_info_t *, + unw_proc_info_t *, int, void *); +static unw_word_t (*unw_find_dyn_list_p) (unw_addr_space_t, unw_dyn_info_t *, + void *); + + +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. */ +#define STRINGIFY2(name) #name +#define STRINGIFY(name) STRINGIFY2(name) + +#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 char *get_reg_name = STRINGIFY(UNW_OBJ(get_reg)); +static char *get_fpreg_name = STRINGIFY(UNW_OBJ(get_fpreg)); +static char *get_saveloc_name = STRINGIFY(UNW_OBJ(get_save_loc)); +static char *is_signal_frame_name = STRINGIFY(UNW_OBJ(is_signal_frame)); +static char *step_name = STRINGIFY(UNW_OBJ(step)); +static char *init_remote_name = STRINGIFY(UNW_OBJ(init_remote)); +static char *create_addr_space_name = STRINGIFY(UNW_OBJ(create_addr_space)); +static char *destroy_addr_space_name = STRINGIFY(UNW_OBJ(destroy_addr_space)); +static char *search_unwind_table_name + = STRINGIFY(UNW_OBJ(search_unwind_table)); +static char *find_dyn_list_name = STRINGIFY(UNW_OBJ(find_dyn_list)); + +static struct libunwind_descr * +libunwind_descr (struct gdbarch *gdbarch) +{ + return gdbarch_data (gdbarch, libunwind_descr_handle); +} + +static void * +libunwind_descr_init (struct gdbarch *gdbarch) +{ + struct libunwind_descr *descr + = GDBARCH_OBSTACK_ZALLOC (gdbarch, 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 = gdbarch_data (gdbarch, libunwind_descr_handle); + + if (arch_descr == NULL) + { + /* First time here. Must initialize data area. */ + arch_descr = libunwind_descr_init (gdbarch); + deprecated_set_gdbarch_data (gdbarch, + libunwind_descr_handle, arch_descr); + } + + /* 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 i, ret; + + if (*this_cache) + return *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 abandonning 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 = 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 = 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 i, 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 = 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); + struct gdbarch *gdbarch = get_frame_arch (this_frame); + + void *ptr; + unw_cursor_t *c; + unw_save_loc_t sl; + int i, 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, + di, 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 i, 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 = 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, struct 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 = 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) + { + fprintf_unfiltered (gdb_stderr, _("[GDB failed to load %s: %s]\n"), + LIBUNWIND_SO, so_error); +#ifdef LIBUNWIND_SO_7 + fprintf_unfiltered (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 = dlsym (handle, get_reg_name); + if (unw_get_reg_p == NULL) + return 0; + + unw_get_fpreg_p = dlsym (handle, get_fpreg_name); + if (unw_get_fpreg_p == NULL) + return 0; + + unw_get_saveloc_p = dlsym (handle, get_saveloc_name); + if (unw_get_saveloc_p == NULL) + return 0; + + unw_is_signal_frame_p = dlsym (handle, is_signal_frame_name); + if (unw_is_signal_frame_p == NULL) + return 0; + + unw_step_p = dlsym (handle, step_name); + if (unw_step_p == NULL) + return 0; + + unw_init_remote_p = dlsym (handle, init_remote_name); + if (unw_init_remote_p == NULL) + return 0; + + unw_create_addr_space_p = dlsym (handle, create_addr_space_name); + if (unw_create_addr_space_p == NULL) + return 0; + + unw_destroy_addr_space_p = dlsym (handle, destroy_addr_space_name); + if (unw_destroy_addr_space_p == NULL) + return 0; + + unw_search_unwind_table_p = dlsym (handle, search_unwind_table_name); + if (unw_search_unwind_table_p == NULL) + return 0; + + unw_find_dyn_list_p = 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; +} + +/* Provide a prototype to silence -Wmissing-prototypes. */ +void _initialize_libunwind_frame (void); + +void +_initialize_libunwind_frame (void) +{ + libunwind_descr_handle + = gdbarch_data_register_post_init (libunwind_descr_init); + + libunwind_initialized = libunwind_load (); +} |