| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * dwarf-aux.c : libdw auxiliary interfaces |
| */ |
| |
| #include <errno.h> |
| #include <inttypes.h> |
| #include <stdbool.h> |
| #include <stdlib.h> |
| #include "debug.h" |
| #include "dwarf-aux.h" |
| #include "strbuf.h" |
| #include "string2.h" |
| |
| /** |
| * cu_find_realpath - Find the realpath of the target file |
| * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit) |
| * @fname: The tail filename of the target file |
| * |
| * Find the real(long) path of @fname in @cu_die. |
| */ |
| const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname) |
| { |
| Dwarf_Files *files; |
| size_t nfiles, i; |
| const char *src = NULL; |
| int ret; |
| |
| if (!fname) |
| return NULL; |
| |
| ret = dwarf_getsrcfiles(cu_die, &files, &nfiles); |
| if (ret != 0) |
| return NULL; |
| |
| for (i = 0; i < nfiles; i++) { |
| src = dwarf_filesrc(files, i, NULL, NULL); |
| if (strtailcmp(src, fname) == 0) |
| break; |
| } |
| if (i == nfiles) |
| return NULL; |
| return src; |
| } |
| |
| /** |
| * cu_get_comp_dir - Get the path of compilation directory |
| * @cu_die: a CU DIE |
| * |
| * Get the path of compilation directory of given @cu_die. |
| * Since this depends on DW_AT_comp_dir, older gcc will not |
| * embedded it. In that case, this returns NULL. |
| */ |
| const char *cu_get_comp_dir(Dwarf_Die *cu_die) |
| { |
| Dwarf_Attribute attr; |
| if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL) |
| return NULL; |
| return dwarf_formstring(&attr); |
| } |
| |
| /** |
| * cu_find_lineinfo - Get a line number and file name for given address |
| * @cu_die: a CU DIE |
| * @addr: An address |
| * @fname: a pointer which returns the file name string |
| * @lineno: a pointer which returns the line number |
| * |
| * Find a line number and file name for @addr in @cu_die. |
| */ |
| int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr, |
| const char **fname, int *lineno) |
| { |
| Dwarf_Line *line; |
| Dwarf_Addr laddr; |
| |
| line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr); |
| if (line && dwarf_lineaddr(line, &laddr) == 0 && |
| addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) { |
| *fname = dwarf_linesrc(line, NULL, NULL); |
| if (!*fname) |
| /* line number is useless without filename */ |
| *lineno = 0; |
| } |
| |
| return *lineno ?: -ENOENT; |
| } |
| |
| static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data); |
| |
| /** |
| * cu_walk_functions_at - Walk on function DIEs at given address |
| * @cu_die: A CU DIE |
| * @addr: An address |
| * @callback: A callback which called with found DIEs |
| * @data: A user data |
| * |
| * Walk on function DIEs at given @addr in @cu_die. Passed DIEs |
| * should be subprogram or inlined-subroutines. |
| */ |
| int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr, |
| int (*callback)(Dwarf_Die *, void *), void *data) |
| { |
| Dwarf_Die die_mem; |
| Dwarf_Die *sc_die; |
| int ret = -ENOENT; |
| |
| /* Inlined function could be recursive. Trace it until fail */ |
| for (sc_die = die_find_realfunc(cu_die, addr, &die_mem); |
| sc_die != NULL; |
| sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr, |
| &die_mem)) { |
| ret = callback(sc_die, data); |
| if (ret) |
| break; |
| } |
| |
| return ret; |
| |
| } |
| |
| /** |
| * die_get_linkage_name - Get the linkage name of the object |
| * @dw_die: A DIE of the object |
| * |
| * Get the linkage name attiribute of given @dw_die. |
| * For C++ binary, the linkage name will be the mangled symbol. |
| */ |
| const char *die_get_linkage_name(Dwarf_Die *dw_die) |
| { |
| Dwarf_Attribute attr; |
| |
| if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL) |
| return NULL; |
| return dwarf_formstring(&attr); |
| } |
| |
| /** |
| * die_compare_name - Compare diename and tname |
| * @dw_die: a DIE |
| * @tname: a string of target name |
| * |
| * Compare the name of @dw_die and @tname. Return false if @dw_die has no name. |
| */ |
| bool die_compare_name(Dwarf_Die *dw_die, const char *tname) |
| { |
| const char *name; |
| |
| name = dwarf_diename(dw_die); |
| return name ? (strcmp(tname, name) == 0) : false; |
| } |
| |
| /** |
| * die_match_name - Match diename/linkage name and glob |
| * @dw_die: a DIE |
| * @glob: a string of target glob pattern |
| * |
| * Glob matching the name of @dw_die and @glob. Return false if matching fail. |
| * This also match linkage name. |
| */ |
| bool die_match_name(Dwarf_Die *dw_die, const char *glob) |
| { |
| const char *name; |
| |
| name = dwarf_diename(dw_die); |
| if (name && strglobmatch(name, glob)) |
| return true; |
| /* fall back to check linkage name */ |
| name = die_get_linkage_name(dw_die); |
| if (name && strglobmatch(name, glob)) |
| return true; |
| |
| return false; |
| } |
| |
| /** |
| * die_get_call_lineno - Get callsite line number of inline-function instance |
| * @in_die: a DIE of an inlined function instance |
| * |
| * Get call-site line number of @in_die. This means from where the inline |
| * function is called. |
| */ |
| int die_get_call_lineno(Dwarf_Die *in_die) |
| { |
| Dwarf_Attribute attr; |
| Dwarf_Word ret; |
| |
| if (!dwarf_attr(in_die, DW_AT_call_line, &attr)) |
| return -ENOENT; |
| |
| dwarf_formudata(&attr, &ret); |
| return (int)ret; |
| } |
| |
| /** |
| * die_get_type - Get type DIE |
| * @vr_die: a DIE of a variable |
| * @die_mem: where to store a type DIE |
| * |
| * Get a DIE of the type of given variable (@vr_die), and store |
| * it to die_mem. Return NULL if fails to get a type DIE. |
| */ |
| Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem) |
| { |
| Dwarf_Attribute attr; |
| |
| if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) && |
| dwarf_formref_die(&attr, die_mem)) |
| return die_mem; |
| else |
| return NULL; |
| } |
| |
| /* Get a type die, but skip qualifiers */ |
| static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem) |
| { |
| int tag; |
| |
| do { |
| vr_die = die_get_type(vr_die, die_mem); |
| if (!vr_die) |
| break; |
| tag = dwarf_tag(vr_die); |
| } while (tag == DW_TAG_const_type || |
| tag == DW_TAG_restrict_type || |
| tag == DW_TAG_volatile_type || |
| tag == DW_TAG_shared_type); |
| |
| return vr_die; |
| } |
| |
| /** |
| * die_get_real_type - Get a type die, but skip qualifiers and typedef |
| * @vr_die: a DIE of a variable |
| * @die_mem: where to store a type DIE |
| * |
| * Get a DIE of the type of given variable (@vr_die), and store |
| * it to die_mem. Return NULL if fails to get a type DIE. |
| * If the type is qualifiers (e.g. const) or typedef, this skips it |
| * and tries to find real type (structure or basic types, e.g. int). |
| */ |
| Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem) |
| { |
| do { |
| vr_die = __die_get_real_type(vr_die, die_mem); |
| } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef); |
| |
| return vr_die; |
| } |
| |
| /* Get attribute and translate it as a udata */ |
| static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name, |
| Dwarf_Word *result) |
| { |
| Dwarf_Attribute attr; |
| |
| if (dwarf_attr(tp_die, attr_name, &attr) == NULL || |
| dwarf_formudata(&attr, result) != 0) |
| return -ENOENT; |
| |
| return 0; |
| } |
| |
| /* Get attribute and translate it as a sdata */ |
| static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name, |
| Dwarf_Sword *result) |
| { |
| Dwarf_Attribute attr; |
| |
| if (dwarf_attr(tp_die, attr_name, &attr) == NULL || |
| dwarf_formsdata(&attr, result) != 0) |
| return -ENOENT; |
| |
| return 0; |
| } |
| |
| /** |
| * die_is_signed_type - Check whether a type DIE is signed or not |
| * @tp_die: a DIE of a type |
| * |
| * Get the encoding of @tp_die and return true if the encoding |
| * is signed. |
| */ |
| bool die_is_signed_type(Dwarf_Die *tp_die) |
| { |
| Dwarf_Word ret; |
| |
| if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret)) |
| return false; |
| |
| return (ret == DW_ATE_signed_char || ret == DW_ATE_signed || |
| ret == DW_ATE_signed_fixed); |
| } |
| |
| /** |
| * die_is_func_def - Ensure that this DIE is a subprogram and definition |
| * @dw_die: a DIE |
| * |
| * Ensure that this DIE is a subprogram and NOT a declaration. This |
| * returns true if @dw_die is a function definition. |
| **/ |
| bool die_is_func_def(Dwarf_Die *dw_die) |
| { |
| Dwarf_Attribute attr; |
| |
| return (dwarf_tag(dw_die) == DW_TAG_subprogram && |
| dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL); |
| } |
| |
| /** |
| * die_entrypc - Returns entry PC (the lowest address) of a DIE |
| * @dw_die: a DIE |
| * @addr: where to store entry PC |
| * |
| * Since dwarf_entrypc() does not return entry PC if the DIE has only address |
| * range, we have to use this to retrieve the lowest address from the address |
| * range attribute. |
| */ |
| int die_entrypc(Dwarf_Die *dw_die, Dwarf_Addr *addr) |
| { |
| Dwarf_Addr base, end; |
| Dwarf_Attribute attr; |
| |
| if (!addr) |
| return -EINVAL; |
| |
| if (dwarf_entrypc(dw_die, addr) == 0) |
| return 0; |
| |
| /* |
| * Since the dwarf_ranges() will return 0 if there is no |
| * DW_AT_ranges attribute, we should check it first. |
| */ |
| if (!dwarf_attr(dw_die, DW_AT_ranges, &attr)) |
| return -ENOENT; |
| |
| return dwarf_ranges(dw_die, 0, &base, addr, &end) < 0 ? -ENOENT : 0; |
| } |
| |
| /** |
| * die_is_func_instance - Ensure that this DIE is an instance of a subprogram |
| * @dw_die: a DIE |
| * |
| * Ensure that this DIE is an instance (which has an entry address). |
| * This returns true if @dw_die is a function instance. If not, the @dw_die |
| * must be a prototype. You can use die_walk_instances() to find actual |
| * instances. |
| **/ |
| bool die_is_func_instance(Dwarf_Die *dw_die) |
| { |
| Dwarf_Addr tmp; |
| Dwarf_Attribute attr_mem; |
| int tag = dwarf_tag(dw_die); |
| |
| if (tag != DW_TAG_subprogram && |
| tag != DW_TAG_inlined_subroutine) |
| return false; |
| |
| return dwarf_entrypc(dw_die, &tmp) == 0 || |
| dwarf_attr(dw_die, DW_AT_ranges, &attr_mem) != NULL; |
| } |
| |
| /** |
| * die_get_data_member_location - Get the data-member offset |
| * @mb_die: a DIE of a member of a data structure |
| * @offs: The offset of the member in the data structure |
| * |
| * Get the offset of @mb_die in the data structure including @mb_die, and |
| * stores result offset to @offs. If any error occurs this returns errno. |
| */ |
| int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs) |
| { |
| Dwarf_Attribute attr; |
| Dwarf_Op *expr; |
| size_t nexpr; |
| int ret; |
| |
| if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL) |
| return -ENOENT; |
| |
| if (dwarf_formudata(&attr, offs) != 0) { |
| /* DW_AT_data_member_location should be DW_OP_plus_uconst */ |
| ret = dwarf_getlocation(&attr, &expr, &nexpr); |
| if (ret < 0 || nexpr == 0) |
| return -ENOENT; |
| |
| if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) { |
| pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n", |
| expr[0].atom, nexpr); |
| return -ENOTSUP; |
| } |
| *offs = (Dwarf_Word)expr[0].number; |
| } |
| return 0; |
| } |
| |
| /* Get the call file index number in CU DIE */ |
| static int die_get_call_fileno(Dwarf_Die *in_die) |
| { |
| Dwarf_Sword idx; |
| |
| if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0) |
| return (int)idx; |
| else |
| return -ENOENT; |
| } |
| |
| /* Get the declared file index number in CU DIE */ |
| static int die_get_decl_fileno(Dwarf_Die *pdie) |
| { |
| Dwarf_Sword idx; |
| |
| if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0) |
| return (int)idx; |
| else |
| return -ENOENT; |
| } |
| |
| /** |
| * die_get_call_file - Get callsite file name of inlined function instance |
| * @in_die: a DIE of an inlined function instance |
| * |
| * Get call-site file name of @in_die. This means from which file the inline |
| * function is called. |
| */ |
| const char *die_get_call_file(Dwarf_Die *in_die) |
| { |
| Dwarf_Die cu_die; |
| Dwarf_Files *files; |
| int idx; |
| |
| idx = die_get_call_fileno(in_die); |
| if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) || |
| dwarf_getsrcfiles(&cu_die, &files, NULL) != 0) |
| return NULL; |
| |
| return dwarf_filesrc(files, idx, NULL, NULL); |
| } |
| |
| |
| /** |
| * die_find_child - Generic DIE search function in DIE tree |
| * @rt_die: a root DIE |
| * @callback: a callback function |
| * @data: a user data passed to the callback function |
| * @die_mem: a buffer for result DIE |
| * |
| * Trace DIE tree from @rt_die and call @callback for each child DIE. |
| * If @callback returns DIE_FIND_CB_END, this stores the DIE into |
| * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE, |
| * this continues to trace the tree. Optionally, @callback can return |
| * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only |
| * the children and trace only the siblings respectively. |
| * Returns NULL if @callback can't find any appropriate DIE. |
| */ |
| Dwarf_Die *die_find_child(Dwarf_Die *rt_die, |
| int (*callback)(Dwarf_Die *, void *), |
| void *data, Dwarf_Die *die_mem) |
| { |
| Dwarf_Die child_die; |
| int ret; |
| |
| ret = dwarf_child(rt_die, die_mem); |
| if (ret != 0) |
| return NULL; |
| |
| do { |
| ret = callback(die_mem, data); |
| if (ret == DIE_FIND_CB_END) |
| return die_mem; |
| |
| if ((ret & DIE_FIND_CB_CHILD) && |
| die_find_child(die_mem, callback, data, &child_die)) { |
| memcpy(die_mem, &child_die, sizeof(Dwarf_Die)); |
| return die_mem; |
| } |
| } while ((ret & DIE_FIND_CB_SIBLING) && |
| dwarf_siblingof(die_mem, die_mem) == 0); |
| |
| return NULL; |
| } |
| |
| struct __addr_die_search_param { |
| Dwarf_Addr addr; |
| Dwarf_Die *die_mem; |
| }; |
| |
| static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data) |
| { |
| struct __addr_die_search_param *ad = data; |
| Dwarf_Addr addr = 0; |
| |
| if (dwarf_tag(fn_die) == DW_TAG_subprogram && |
| !dwarf_highpc(fn_die, &addr) && |
| addr == ad->addr) { |
| memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die)); |
| return DWARF_CB_ABORT; |
| } |
| return DWARF_CB_OK; |
| } |
| |
| /** |
| * die_find_tailfunc - Search for a non-inlined function with tail call at |
| * given address |
| * @cu_die: a CU DIE which including @addr |
| * @addr: target address |
| * @die_mem: a buffer for result DIE |
| * |
| * Search for a non-inlined function DIE with tail call at @addr. Stores the |
| * DIE to @die_mem and returns it if found. Returns NULL if failed. |
| */ |
| Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr, |
| Dwarf_Die *die_mem) |
| { |
| struct __addr_die_search_param ad; |
| ad.addr = addr; |
| ad.die_mem = die_mem; |
| /* dwarf_getscopes can't find subprogram. */ |
| if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0)) |
| return NULL; |
| else |
| return die_mem; |
| } |
| |
| /* die_find callback for non-inlined function search */ |
| static int __die_search_func_cb(Dwarf_Die *fn_die, void *data) |
| { |
| struct __addr_die_search_param *ad = data; |
| |
| /* |
| * Since a declaration entry doesn't has given pc, this always returns |
| * function definition entry. |
| */ |
| if (dwarf_tag(fn_die) == DW_TAG_subprogram && |
| dwarf_haspc(fn_die, ad->addr)) { |
| memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die)); |
| return DWARF_CB_ABORT; |
| } |
| return DWARF_CB_OK; |
| } |
| |
| /** |
| * die_find_realfunc - Search a non-inlined function at given address |
| * @cu_die: a CU DIE which including @addr |
| * @addr: target address |
| * @die_mem: a buffer for result DIE |
| * |
| * Search a non-inlined function DIE which includes @addr. Stores the |
| * DIE to @die_mem and returns it if found. Returns NULL if failed. |
| */ |
| Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr, |
| Dwarf_Die *die_mem) |
| { |
| struct __addr_die_search_param ad; |
| ad.addr = addr; |
| ad.die_mem = die_mem; |
| /* dwarf_getscopes can't find subprogram. */ |
| if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0)) |
| return NULL; |
| else |
| return die_mem; |
| } |
| |
| /* die_find callback for inline function search */ |
| static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data) |
| { |
| Dwarf_Addr *addr = data; |
| |
| if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine && |
| dwarf_haspc(die_mem, *addr)) |
| return DIE_FIND_CB_END; |
| |
| return DIE_FIND_CB_CONTINUE; |
| } |
| |
| /** |
| * die_find_top_inlinefunc - Search the top inlined function at given address |
| * @sp_die: a subprogram DIE which including @addr |
| * @addr: target address |
| * @die_mem: a buffer for result DIE |
| * |
| * Search an inlined function DIE which includes @addr. Stores the |
| * DIE to @die_mem and returns it if found. Returns NULL if failed. |
| * Even if several inlined functions are expanded recursively, this |
| * doesn't trace it down, and returns the topmost one. |
| */ |
| Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, |
| Dwarf_Die *die_mem) |
| { |
| return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem); |
| } |
| |
| /** |
| * die_find_inlinefunc - Search an inlined function at given address |
| * @sp_die: a subprogram DIE which including @addr |
| * @addr: target address |
| * @die_mem: a buffer for result DIE |
| * |
| * Search an inlined function DIE which includes @addr. Stores the |
| * DIE to @die_mem and returns it if found. Returns NULL if failed. |
| * If several inlined functions are expanded recursively, this trace |
| * it down and returns deepest one. |
| */ |
| Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, |
| Dwarf_Die *die_mem) |
| { |
| Dwarf_Die tmp_die; |
| |
| sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die); |
| if (!sp_die) |
| return NULL; |
| |
| /* Inlined function could be recursive. Trace it until fail */ |
| while (sp_die) { |
| memcpy(die_mem, sp_die, sizeof(Dwarf_Die)); |
| sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, |
| &tmp_die); |
| } |
| |
| return die_mem; |
| } |
| |
| struct __instance_walk_param { |
| void *addr; |
| int (*callback)(Dwarf_Die *, void *); |
| void *data; |
| int retval; |
| }; |
| |
| static int __die_walk_instances_cb(Dwarf_Die *inst, void *data) |
| { |
| struct __instance_walk_param *iwp = data; |
| Dwarf_Attribute attr_mem; |
| Dwarf_Die origin_mem; |
| Dwarf_Attribute *attr; |
| Dwarf_Die *origin; |
| int tmp; |
| |
| if (!die_is_func_instance(inst)) |
| return DIE_FIND_CB_CONTINUE; |
| |
| attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem); |
| if (attr == NULL) |
| return DIE_FIND_CB_CONTINUE; |
| |
| origin = dwarf_formref_die(attr, &origin_mem); |
| if (origin == NULL || origin->addr != iwp->addr) |
| return DIE_FIND_CB_CONTINUE; |
| |
| /* Ignore redundant instances */ |
| if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) { |
| dwarf_decl_line(origin, &tmp); |
| if (die_get_call_lineno(inst) == tmp) { |
| tmp = die_get_decl_fileno(origin); |
| if (die_get_call_fileno(inst) == tmp) |
| return DIE_FIND_CB_CONTINUE; |
| } |
| } |
| |
| iwp->retval = iwp->callback(inst, iwp->data); |
| |
| return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE; |
| } |
| |
| /** |
| * die_walk_instances - Walk on instances of given DIE |
| * @or_die: an abstract original DIE |
| * @callback: a callback function which is called with instance DIE |
| * @data: user data |
| * |
| * Walk on the instances of give @in_die. @in_die must be an inlined function |
| * declartion. This returns the return value of @callback if it returns |
| * non-zero value, or -ENOENT if there is no instance. |
| */ |
| int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *), |
| void *data) |
| { |
| Dwarf_Die cu_die; |
| Dwarf_Die die_mem; |
| struct __instance_walk_param iwp = { |
| .addr = or_die->addr, |
| .callback = callback, |
| .data = data, |
| .retval = -ENOENT, |
| }; |
| |
| if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL) |
| return -ENOENT; |
| |
| die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem); |
| |
| return iwp.retval; |
| } |
| |
| /* Line walker internal parameters */ |
| struct __line_walk_param { |
| bool recursive; |
| line_walk_callback_t callback; |
| void *data; |
| int retval; |
| }; |
| |
| static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data) |
| { |
| struct __line_walk_param *lw = data; |
| Dwarf_Addr addr = 0; |
| const char *fname; |
| int lineno; |
| |
| if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) { |
| fname = die_get_call_file(in_die); |
| lineno = die_get_call_lineno(in_die); |
| if (fname && lineno > 0 && die_entrypc(in_die, &addr) == 0) { |
| lw->retval = lw->callback(fname, lineno, addr, lw->data); |
| if (lw->retval != 0) |
| return DIE_FIND_CB_END; |
| } |
| if (!lw->recursive) |
| return DIE_FIND_CB_SIBLING; |
| } |
| |
| if (addr) { |
| fname = dwarf_decl_file(in_die); |
| if (fname && dwarf_decl_line(in_die, &lineno) == 0) { |
| lw->retval = lw->callback(fname, lineno, addr, lw->data); |
| if (lw->retval != 0) |
| return DIE_FIND_CB_END; |
| } |
| } |
| |
| /* Continue to search nested inlined function call-sites */ |
| return DIE_FIND_CB_CONTINUE; |
| } |
| |
| /* Walk on lines of blocks included in given DIE */ |
| static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive, |
| line_walk_callback_t callback, void *data) |
| { |
| struct __line_walk_param lw = { |
| .recursive = recursive, |
| .callback = callback, |
| .data = data, |
| .retval = 0, |
| }; |
| Dwarf_Die die_mem; |
| Dwarf_Addr addr; |
| const char *fname; |
| int lineno; |
| |
| /* Handle function declaration line */ |
| fname = dwarf_decl_file(sp_die); |
| if (fname && dwarf_decl_line(sp_die, &lineno) == 0 && |
| die_entrypc(sp_die, &addr) == 0) { |
| lw.retval = callback(fname, lineno, addr, data); |
| if (lw.retval != 0) |
| goto done; |
| } |
| die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem); |
| done: |
| return lw.retval; |
| } |
| |
| static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data) |
| { |
| struct __line_walk_param *lw = data; |
| |
| /* |
| * Since inlined function can include another inlined function in |
| * the same file, we need to walk in it recursively. |
| */ |
| lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data); |
| if (lw->retval != 0) |
| return DWARF_CB_ABORT; |
| |
| return DWARF_CB_OK; |
| } |
| |
| /** |
| * die_walk_lines - Walk on lines inside given DIE |
| * @rt_die: a root DIE (CU, subprogram or inlined_subroutine) |
| * @callback: callback routine |
| * @data: user data |
| * |
| * Walk on all lines inside given @rt_die and call @callback on each line. |
| * If the @rt_die is a function, walk only on the lines inside the function, |
| * otherwise @rt_die must be a CU DIE. |
| * Note that this walks not only dwarf line list, but also function entries |
| * and inline call-site. |
| */ |
| int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data) |
| { |
| Dwarf_Lines *lines; |
| Dwarf_Line *line; |
| Dwarf_Addr addr; |
| const char *fname, *decf = NULL, *inf = NULL; |
| int lineno, ret = 0; |
| int decl = 0, inl; |
| Dwarf_Die die_mem, *cu_die; |
| size_t nlines, i; |
| bool flag; |
| |
| /* Get the CU die */ |
| if (dwarf_tag(rt_die) != DW_TAG_compile_unit) { |
| cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL); |
| dwarf_decl_line(rt_die, &decl); |
| decf = dwarf_decl_file(rt_die); |
| } else |
| cu_die = rt_die; |
| if (!cu_die) { |
| pr_debug2("Failed to get CU from given DIE.\n"); |
| return -EINVAL; |
| } |
| |
| /* Get lines list in the CU */ |
| if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) { |
| pr_debug2("Failed to get source lines on this CU.\n"); |
| return -ENOENT; |
| } |
| pr_debug2("Get %zd lines from this CU\n", nlines); |
| |
| /* Walk on the lines on lines list */ |
| for (i = 0; i < nlines; i++) { |
| line = dwarf_onesrcline(lines, i); |
| if (line == NULL || |
| dwarf_lineno(line, &lineno) != 0 || |
| dwarf_lineaddr(line, &addr) != 0) { |
| pr_debug2("Failed to get line info. " |
| "Possible error in debuginfo.\n"); |
| continue; |
| } |
| /* Skip end-of-sequence */ |
| if (dwarf_lineendsequence(line, &flag) != 0 || flag) |
| continue; |
| /* Skip Non statement line-info */ |
| if (dwarf_linebeginstatement(line, &flag) != 0 || !flag) |
| continue; |
| /* Filter lines based on address */ |
| if (rt_die != cu_die) { |
| /* |
| * Address filtering |
| * The line is included in given function, and |
| * no inline block includes it. |
| */ |
| if (!dwarf_haspc(rt_die, addr)) |
| continue; |
| |
| if (die_find_inlinefunc(rt_die, addr, &die_mem)) { |
| /* Call-site check */ |
| inf = die_get_call_file(&die_mem); |
| if ((inf && !strcmp(inf, decf)) && |
| die_get_call_lineno(&die_mem) == lineno) |
| goto found; |
| |
| dwarf_decl_line(&die_mem, &inl); |
| if (inl != decl || |
| decf != dwarf_decl_file(&die_mem)) |
| continue; |
| } |
| } |
| found: |
| /* Get source line */ |
| fname = dwarf_linesrc(line, NULL, NULL); |
| |
| ret = callback(fname, lineno, addr, data); |
| if (ret != 0) |
| return ret; |
| } |
| |
| /* |
| * Dwarf lines doesn't include function declarations and inlined |
| * subroutines. We have to check functions list or given function. |
| */ |
| if (rt_die != cu_die) |
| /* |
| * Don't need walk inlined functions recursively, because |
| * inner inlined functions don't have the lines of the |
| * specified function. |
| */ |
| ret = __die_walk_funclines(rt_die, false, callback, data); |
| else { |
| struct __line_walk_param param = { |
| .callback = callback, |
| .data = data, |
| .retval = 0, |
| }; |
| dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0); |
| ret = param.retval; |
| } |
| |
| return ret; |
| } |
| |
| struct __find_variable_param { |
| const char *name; |
| Dwarf_Addr addr; |
| }; |
| |
| static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data) |
| { |
| struct __find_variable_param *fvp = data; |
| Dwarf_Attribute attr; |
| int tag; |
| |
| tag = dwarf_tag(die_mem); |
| if ((tag == DW_TAG_formal_parameter || |
| tag == DW_TAG_variable) && |
| die_compare_name(die_mem, fvp->name) && |
| /* Does the DIE have location information or external instance? */ |
| (dwarf_attr(die_mem, DW_AT_external, &attr) || |
| dwarf_attr(die_mem, DW_AT_location, &attr))) |
| return DIE_FIND_CB_END; |
| if (dwarf_haspc(die_mem, fvp->addr)) |
| return DIE_FIND_CB_CONTINUE; |
| else |
| return DIE_FIND_CB_SIBLING; |
| } |
| |
| /** |
| * die_find_variable_at - Find a given name variable at given address |
| * @sp_die: a function DIE |
| * @name: variable name |
| * @addr: address |
| * @die_mem: a buffer for result DIE |
| * |
| * Find a variable DIE called @name at @addr in @sp_die. |
| */ |
| Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name, |
| Dwarf_Addr addr, Dwarf_Die *die_mem) |
| { |
| struct __find_variable_param fvp = { .name = name, .addr = addr}; |
| |
| return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp, |
| die_mem); |
| } |
| |
| static int __die_find_member_cb(Dwarf_Die *die_mem, void *data) |
| { |
| const char *name = data; |
| |
| if (dwarf_tag(die_mem) == DW_TAG_member) { |
| if (die_compare_name(die_mem, name)) |
| return DIE_FIND_CB_END; |
| else if (!dwarf_diename(die_mem)) { /* Unnamed structure */ |
| Dwarf_Die type_die, tmp_die; |
| if (die_get_type(die_mem, &type_die) && |
| die_find_member(&type_die, name, &tmp_die)) |
| return DIE_FIND_CB_END; |
| } |
| } |
| return DIE_FIND_CB_SIBLING; |
| } |
| |
| /** |
| * die_find_member - Find a given name member in a data structure |
| * @st_die: a data structure type DIE |
| * @name: member name |
| * @die_mem: a buffer for result DIE |
| * |
| * Find a member DIE called @name in @st_die. |
| */ |
| Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name, |
| Dwarf_Die *die_mem) |
| { |
| return die_find_child(st_die, __die_find_member_cb, (void *)name, |
| die_mem); |
| } |
| |
| /** |
| * die_get_typename - Get the name of given variable DIE |
| * @vr_die: a variable DIE |
| * @buf: a strbuf for result type name |
| * |
| * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded. |
| * and Return -ENOENT if failed to find type name. |
| * Note that the result will stores typedef name if possible, and stores |
| * "*(function_type)" if the type is a function pointer. |
| */ |
| int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf) |
| { |
| Dwarf_Die type; |
| int tag, ret; |
| const char *tmp = ""; |
| |
| if (__die_get_real_type(vr_die, &type) == NULL) |
| return -ENOENT; |
| |
| tag = dwarf_tag(&type); |
| if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type) |
| tmp = "*"; |
| else if (tag == DW_TAG_subroutine_type) { |
| /* Function pointer */ |
| return strbuf_add(buf, "(function_type)", 15); |
| } else { |
| if (!dwarf_diename(&type)) |
| return -ENOENT; |
| if (tag == DW_TAG_union_type) |
| tmp = "union "; |
| else if (tag == DW_TAG_structure_type) |
| tmp = "struct "; |
| else if (tag == DW_TAG_enumeration_type) |
| tmp = "enum "; |
| /* Write a base name */ |
| return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type)); |
| } |
| ret = die_get_typename(&type, buf); |
| return ret ? ret : strbuf_addstr(buf, tmp); |
| } |
| |
| /** |
| * die_get_varname - Get the name and type of given variable DIE |
| * @vr_die: a variable DIE |
| * @buf: a strbuf for type and variable name |
| * |
| * Get the name and type of @vr_die and stores it in @buf as "type\tname". |
| */ |
| int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf) |
| { |
| int ret; |
| |
| ret = die_get_typename(vr_die, buf); |
| if (ret < 0) { |
| pr_debug("Failed to get type, make it unknown.\n"); |
| ret = strbuf_add(buf, " (unknown_type)", 14); |
| } |
| |
| return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die)); |
| } |
| |
| #ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT |
| /** |
| * die_get_var_innermost_scope - Get innermost scope range of given variable DIE |
| * @sp_die: a subprogram DIE |
| * @vr_die: a variable DIE |
| * @buf: a strbuf for variable byte offset range |
| * |
| * Get the innermost scope range of @vr_die and stores it in @buf as |
| * "@<function_name+[NN-NN,NN-NN]>". |
| */ |
| static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die, |
| struct strbuf *buf) |
| { |
| Dwarf_Die *scopes; |
| int count; |
| size_t offset = 0; |
| Dwarf_Addr base; |
| Dwarf_Addr start, end; |
| Dwarf_Addr entry; |
| int ret; |
| bool first = true; |
| const char *name; |
| |
| ret = die_entrypc(sp_die, &entry); |
| if (ret) |
| return ret; |
| |
| name = dwarf_diename(sp_die); |
| if (!name) |
| return -ENOENT; |
| |
| count = dwarf_getscopes_die(vr_die, &scopes); |
| |
| /* (*SCOPES)[1] is the DIE for the scope containing that scope */ |
| if (count <= 1) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| while ((offset = dwarf_ranges(&scopes[1], offset, &base, |
| &start, &end)) > 0) { |
| start -= entry; |
| end -= entry; |
| |
| if (first) { |
| ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64, |
| name, start, end); |
| first = false; |
| } else { |
| ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64, |
| start, end); |
| } |
| if (ret < 0) |
| goto out; |
| } |
| |
| if (!first) |
| ret = strbuf_add(buf, "]>", 2); |
| |
| out: |
| free(scopes); |
| return ret; |
| } |
| |
| /** |
| * die_get_var_range - Get byte offset range of given variable DIE |
| * @sp_die: a subprogram DIE |
| * @vr_die: a variable DIE |
| * @buf: a strbuf for type and variable name and byte offset range |
| * |
| * Get the byte offset range of @vr_die and stores it in @buf as |
| * "@<function_name+[NN-NN,NN-NN]>". |
| */ |
| int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf) |
| { |
| int ret = 0; |
| Dwarf_Addr base; |
| Dwarf_Addr start, end; |
| Dwarf_Addr entry; |
| Dwarf_Op *op; |
| size_t nops; |
| size_t offset = 0; |
| Dwarf_Attribute attr; |
| bool first = true; |
| const char *name; |
| |
| ret = die_entrypc(sp_die, &entry); |
| if (ret) |
| return ret; |
| |
| name = dwarf_diename(sp_die); |
| if (!name) |
| return -ENOENT; |
| |
| if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL) |
| return -EINVAL; |
| |
| while ((offset = dwarf_getlocations(&attr, offset, &base, |
| &start, &end, &op, &nops)) > 0) { |
| if (start == 0) { |
| /* Single Location Descriptions */ |
| ret = die_get_var_innermost_scope(sp_die, vr_die, buf); |
| goto out; |
| } |
| |
| /* Location Lists */ |
| start -= entry; |
| end -= entry; |
| if (first) { |
| ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64, |
| name, start, end); |
| first = false; |
| } else { |
| ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64, |
| start, end); |
| } |
| if (ret < 0) |
| goto out; |
| } |
| |
| if (!first) |
| ret = strbuf_add(buf, "]>", 2); |
| out: |
| return ret; |
| } |
| #else |
| int die_get_var_range(Dwarf_Die *sp_die __maybe_unused, |
| Dwarf_Die *vr_die __maybe_unused, |
| struct strbuf *buf __maybe_unused) |
| { |
| return -ENOTSUP; |
| } |
| #endif |
| |
| /* |
| * die_has_loclist - Check if DW_AT_location of @vr_die is a location list |
| * @vr_die: a variable DIE |
| */ |
| static bool die_has_loclist(Dwarf_Die *vr_die) |
| { |
| Dwarf_Attribute loc; |
| int tag = dwarf_tag(vr_die); |
| |
| if (tag != DW_TAG_formal_parameter && |
| tag != DW_TAG_variable) |
| return false; |
| |
| return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) && |
| dwarf_whatform(&loc) == DW_FORM_sec_offset); |
| } |
| |
| /* |
| * die_is_optimized_target - Check if target program is compiled with |
| * optimization |
| * @cu_die: a CU DIE |
| * |
| * For any object in given CU whose DW_AT_location is a location list, |
| * target program is compiled with optimization. This is applicable to |
| * clang as well. |
| */ |
| bool die_is_optimized_target(Dwarf_Die *cu_die) |
| { |
| Dwarf_Die tmp_die; |
| |
| if (die_has_loclist(cu_die)) |
| return true; |
| |
| if (!dwarf_child(cu_die, &tmp_die) && |
| die_is_optimized_target(&tmp_die)) |
| return true; |
| |
| if (!dwarf_siblingof(cu_die, &tmp_die) && |
| die_is_optimized_target(&tmp_die)) |
| return true; |
| |
| return false; |
| } |
| |
| /* |
| * die_search_idx - Search index of given line address |
| * @lines: Line records of single CU |
| * @nr_lines: Number of @lines |
| * @addr: address we are looking for |
| * @idx: index to be set by this function (return value) |
| * |
| * Search for @addr by looping over every lines of CU. If address |
| * matches, set index of that line in @idx. Note that single source |
| * line can have multiple line records. i.e. single source line can |
| * have multiple index. |
| */ |
| static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines, |
| Dwarf_Addr addr, unsigned long *idx) |
| { |
| unsigned long i; |
| Dwarf_Addr tmp; |
| |
| for (i = 0; i < nr_lines; i++) { |
| if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp)) |
| return false; |
| |
| if (tmp == addr) { |
| *idx = i; |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /* |
| * die_get_postprologue_addr - Search next address after function prologue |
| * @entrypc_idx: entrypc index |
| * @lines: Line records of single CU |
| * @nr_lines: Number of @lines |
| * @hignpc: high PC address of function |
| * @postprologue_addr: Next address after function prologue (return value) |
| * |
| * Look for prologue-end marker. If there is no explicit marker, return |
| * address of next line record or next source line. |
| */ |
| static bool die_get_postprologue_addr(unsigned long entrypc_idx, |
| Dwarf_Lines *lines, |
| unsigned long nr_lines, |
| Dwarf_Addr highpc, |
| Dwarf_Addr *postprologue_addr) |
| { |
| unsigned long i; |
| int entrypc_lno, lno; |
| Dwarf_Line *line; |
| Dwarf_Addr addr; |
| bool p_end; |
| |
| /* entrypc_lno is actual source line number */ |
| line = dwarf_onesrcline(lines, entrypc_idx); |
| if (dwarf_lineno(line, &entrypc_lno)) |
| return false; |
| |
| for (i = entrypc_idx; i < nr_lines; i++) { |
| line = dwarf_onesrcline(lines, i); |
| |
| if (dwarf_lineaddr(line, &addr) || |
| dwarf_lineno(line, &lno) || |
| dwarf_lineprologueend(line, &p_end)) |
| return false; |
| |
| /* highpc is exclusive. [entrypc,highpc) */ |
| if (addr >= highpc) |
| break; |
| |
| /* clang supports prologue-end marker */ |
| if (p_end) |
| break; |
| |
| /* Actual next line in source */ |
| if (lno != entrypc_lno) |
| break; |
| |
| /* |
| * Single source line can have multiple line records. |
| * For Example, |
| * void foo() { printf("hello\n"); } |
| * contains two line records. One points to declaration and |
| * other points to printf() line. Variable 'lno' won't get |
| * incremented in this case but 'i' will. |
| */ |
| if (i != entrypc_idx) |
| break; |
| } |
| |
| dwarf_lineaddr(line, postprologue_addr); |
| if (*postprologue_addr >= highpc) |
| dwarf_lineaddr(dwarf_onesrcline(lines, i - 1), |
| postprologue_addr); |
| |
| return true; |
| } |
| |
| /* |
| * die_skip_prologue - Use next address after prologue as probe location |
| * @sp_die: a subprogram DIE |
| * @cu_die: a CU DIE |
| * @entrypc: entrypc of the function |
| * |
| * Function prologue prepares stack and registers before executing function |
| * logic. When target program is compiled without optimization, function |
| * parameter information is only valid after prologue. When we probe entrypc |
| * of the function, and try to record function parameter, it contains |
| * garbage value. |
| */ |
| void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die, |
| Dwarf_Addr *entrypc) |
| { |
| size_t nr_lines = 0; |
| unsigned long entrypc_idx = 0; |
| Dwarf_Lines *lines = NULL; |
| Dwarf_Addr postprologue_addr; |
| Dwarf_Addr highpc; |
| |
| if (dwarf_highpc(sp_die, &highpc)) |
| return; |
| |
| if (dwarf_getsrclines(cu_die, &lines, &nr_lines)) |
| return; |
| |
| if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx)) |
| return; |
| |
| if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines, |
| highpc, &postprologue_addr)) |
| return; |
| |
| *entrypc = postprologue_addr; |
| } |