diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/perf/util/dwarf-aux.c | 825 |
1 files changed, 758 insertions, 67 deletions
diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index aa898014ad12..44ef968a7ad3 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -9,6 +9,7 @@ #include <stdlib.h> #include "debug.h" #include "dwarf-aux.h" +#include "dwarf-regs.h" #include "strbuf.h" #include "string2.h" @@ -91,7 +92,7 @@ static Dwarf_Line *cu_getsrc_die(Dwarf_Die *cu_die, Dwarf_Addr addr) return NULL; } while (laddr == addr); l++; - /* Going foward to find the statement line */ + /* Going forward to find the statement line */ do { line = dwarf_onesrcline(lines, l++); if (!line || dwarf_lineaddr(line, &laddr) != 0 || @@ -113,22 +114,22 @@ static Dwarf_Line *cu_getsrc_die(Dwarf_Die *cu_die, Dwarf_Addr addr) * * 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) +int cu_find_lineinfo(Dwarf_Die *cu_die, Dwarf_Addr addr, + const char **fname, int *lineno) { Dwarf_Line *line; Dwarf_Die die_mem; Dwarf_Addr faddr; - if (die_find_realfunc(cu_die, (Dwarf_Addr)addr, &die_mem) + if (die_find_realfunc(cu_die, addr, &die_mem) && die_entrypc(&die_mem, &faddr) == 0 && faddr == addr) { - *fname = dwarf_decl_file(&die_mem); + *fname = die_get_decl_file(&die_mem); dwarf_decl_line(&die_mem, lineno); goto out; } - line = cu_getsrc_die(cu_die, (Dwarf_Addr)addr); + line = cu_getsrc_die(cu_die, addr); if (line && dwarf_lineno(line, lineno) == 0) { *fname = dwarf_linesrc(line, NULL, NULL); if (!*fname) @@ -137,7 +138,7 @@ int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr, } out: - return *lineno ?: -ENOENT; + return (*lineno && *fname) ? *lineno : -ENOENT; } static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data); @@ -177,7 +178,7 @@ int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr, * 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. + * Get the linkage name attribute 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) @@ -308,26 +309,13 @@ static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name, { Dwarf_Attribute attr; - if (dwarf_attr(tp_die, attr_name, &attr) == NULL || + if (dwarf_attr_integrate(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 @@ -356,9 +344,25 @@ bool die_is_signed_type(Dwarf_Die *tp_die) bool die_is_func_def(Dwarf_Die *dw_die) { Dwarf_Attribute attr; + Dwarf_Addr addr = 0; + + if (dwarf_tag(dw_die) != DW_TAG_subprogram) + return false; - return (dwarf_tag(dw_die) == DW_TAG_subprogram && - dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL); + if (dwarf_attr(dw_die, DW_AT_declaration, &attr)) + return false; + + /* + * DW_AT_declaration can be lost from function declaration + * by gcc's bug #97060. + * So we need to check this subprogram DIE has DW_AT_inline + * or an entry address. + */ + if (!dwarf_attr(dw_die, DW_AT_inline, &attr) && + die_entrypc(dw_die, &addr) < 0) + return false; + + return true; } /** @@ -373,6 +377,7 @@ bool die_is_func_def(Dwarf_Die *dw_die) int die_entrypc(Dwarf_Die *dw_die, Dwarf_Addr *addr) { Dwarf_Addr base, end; + Dwarf_Attribute attr; if (!addr) return -EINVAL; @@ -380,6 +385,13 @@ int die_entrypc(Dwarf_Die *dw_die, Dwarf_Addr *addr) 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; } @@ -443,9 +455,9 @@ int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs) /* Get the call file index number in CU DIE */ static int die_get_call_fileno(Dwarf_Die *in_die) { - Dwarf_Sword idx; + Dwarf_Word idx; - if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0) + if (die_get_attr_udata(in_die, DW_AT_call_file, &idx) == 0) return (int)idx; else return -ENOENT; @@ -454,14 +466,29 @@ static int die_get_call_fileno(Dwarf_Die *in_die) /* Get the declared file index number in CU DIE */ static int die_get_decl_fileno(Dwarf_Die *pdie) { - Dwarf_Sword idx; + Dwarf_Word idx; - if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0) + if (die_get_attr_udata(pdie, DW_AT_decl_file, &idx) == 0) return (int)idx; else return -ENOENT; } +/* Return the file name by index */ +static const char *die_get_file_name(Dwarf_Die *dw_die, int idx) +{ + Dwarf_Die cu_die; + Dwarf_Files *files; + Dwarf_Attribute attr_mem; + + if (idx < 0 || !dwarf_attr_integrate(dw_die, DW_AT_decl_file, &attr_mem) || + !dwarf_cu_die(attr_mem.cu, &cu_die, NULL, NULL, NULL, NULL, NULL, NULL) || + dwarf_getsrcfiles(&cu_die, &files, NULL) != 0) + return NULL; + + return dwarf_filesrc(files, idx, NULL, NULL); +} + /** * die_get_call_file - Get callsite file name of inlined function instance * @in_die: a DIE of an inlined function instance @@ -471,18 +498,22 @@ static int die_get_decl_fileno(Dwarf_Die *pdie) */ 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); + return die_get_file_name(in_die, die_get_call_fileno(in_die)); } +/** + * die_get_decl_file - Find the declared file name of this DIE + * @dw_die: a DIE for something declared. + * + * Get declared file name of @dw_die. + * NOTE: Since some version of clang DWARF5 implementation incorrectly uses + * file index 0 for DW_AT_decl_file, die_get_decl_file() will return NULL for + * such cases. Use this function instead. + */ +const char *die_get_decl_file(Dwarf_Die *dw_die) +{ + return die_get_file_name(dw_die, die_get_decl_fileno(dw_die)); +} /** * die_find_child - Generic DIE search function in DIE tree @@ -666,6 +697,49 @@ Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, return die_mem; } +static int __die_find_func_rettype_cb(Dwarf_Die *die_mem, void *data) +{ + const char *func_name; + + if (dwarf_tag(die_mem) != DW_TAG_subprogram) + return DIE_FIND_CB_SIBLING; + + func_name = dwarf_diename(die_mem); + if (func_name && !strcmp(func_name, data)) + return DIE_FIND_CB_END; + + return DIE_FIND_CB_SIBLING; +} + +/** + * die_find_func_rettype - Search a return type of function + * @cu_die: a CU DIE + * @name: target function name + * @die_mem: a buffer for result DIE + * + * Search a non-inlined function which matches to @name and stores the + * return type of the function to @die_mem and returns it if found. + * Returns NULL if failed. Note that it doesn't needs to find a + * definition of the function, so it doesn't match with address. + * Most likely, it can find a declaration at the top level. Thus the + * callback function continues to sibling entries only. + */ +Dwarf_Die *die_find_func_rettype(Dwarf_Die *cu_die, const char *name, + Dwarf_Die *die_mem) +{ + Dwarf_Die tmp_die; + + cu_die = die_find_child(cu_die, __die_find_func_rettype_cb, + (void *)name, &tmp_die); + if (!cu_die) + return NULL; + + if (die_get_real_type(&tmp_die, die_mem) == NULL) + return NULL; + + return die_mem; +} + struct __instance_walk_param { void *addr; int (*callback)(Dwarf_Die *, void *); @@ -715,7 +789,7 @@ static int __die_walk_instances_cb(Dwarf_Die *inst, void *data) * @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 + * declaration. 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 *), @@ -766,7 +840,7 @@ static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data) } if (addr) { - fname = dwarf_decl_file(in_die); + fname = die_get_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) @@ -794,7 +868,7 @@ static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive, int lineno; /* Handle function declaration line */ - fname = dwarf_decl_file(sp_die); + fname = die_get_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); @@ -849,7 +923,12 @@ int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data) 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); + decf = die_get_decl_file(rt_die); + if (!decf) { + pr_debug2("Failed to get the declared file name of %s\n", + dwarf_diename(rt_die)); + return -EINVAL; + } } else cu_die = rt_die; if (!cu_die) { @@ -899,7 +978,7 @@ int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data) dwarf_decl_line(&die_mem, &inl); if (inl != decl || - decf != dwarf_decl_file(&die_mem)) + decf != die_get_decl_file(&die_mem)) continue; } } @@ -951,9 +1030,13 @@ static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data) 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? */ + /* + * Does the DIE have location information or const value + * or external instance? + */ (dwarf_attr(die_mem, DW_AT_external, &attr) || - dwarf_attr(die_mem, DW_AT_location, &attr))) + dwarf_attr(die_mem, DW_AT_location, &attr) || + dwarf_attr(die_mem, DW_AT_const_value, &attr))) return DIE_FIND_CB_END; if (dwarf_haspc(die_mem, fvp->addr)) return DIE_FIND_CB_CONTINUE; @@ -1012,44 +1095,71 @@ Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name, } /** - * die_get_typename - Get the name of given variable DIE - * @vr_die: a variable DIE + * die_get_typename_from_type - Get the name of given type DIE + * @type_die: a type DIE * @buf: a strbuf for result type name * - * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded. + * Get the name of @type_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) +int die_get_typename_from_type(Dwarf_Die *type_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) + tag = dwarf_tag(type_die); + if (tag == DW_TAG_pointer_type) tmp = "*"; + else if (tag == DW_TAG_array_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; + const char *name = dwarf_diename(type_die); + 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 "; + else if (name == NULL) + return -ENOENT; /* Write a base name */ - return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type)); + return strbuf_addf(buf, "%s%s", tmp, name ?: ""); + } + ret = die_get_typename(type_die, buf); + if (ret < 0) { + /* void pointer has no type attribute */ + if (tag == DW_TAG_pointer_type && ret == -ENOENT) + return strbuf_addf(buf, "void*"); + + return ret; } - ret = die_get_typename(&type, buf); - return ret ? ret : strbuf_addstr(buf, tmp); + return strbuf_addstr(buf, tmp); +} + +/** + * 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; + + if (__die_get_real_type(vr_die, &type) == NULL) + return -ENOENT; + + return die_get_typename_from_type(&type, buf); } /** @@ -1066,12 +1176,77 @@ int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf) 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); + ret = strbuf_add(buf, "(unknown_type)", 14); } return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die)); } +#if defined(HAVE_DWARF_GETLOCATIONS_SUPPORT) || defined(HAVE_DWARF_CFI_SUPPORT) +static int reg_from_dwarf_op(Dwarf_Op *op) +{ + switch (op->atom) { + case DW_OP_reg0 ... DW_OP_reg31: + return op->atom - DW_OP_reg0; + case DW_OP_breg0 ... DW_OP_breg31: + return op->atom - DW_OP_breg0; + case DW_OP_regx: + case DW_OP_bregx: + return op->number; + case DW_OP_fbreg: + return DWARF_REG_FB; + default: + break; + } + return -1; +} + +static int offset_from_dwarf_op(Dwarf_Op *op) +{ + switch (op->atom) { + case DW_OP_reg0 ... DW_OP_reg31: + case DW_OP_regx: + return 0; + case DW_OP_breg0 ... DW_OP_breg31: + case DW_OP_fbreg: + return op->number; + case DW_OP_bregx: + return op->number2; + default: + break; + } + return -1; +} + +static bool check_allowed_ops(Dwarf_Op *ops, size_t nops) +{ + /* The first op is checked separately */ + ops++; + nops--; + + /* + * It needs to make sure if the location expression matches to the given + * register and offset exactly. Thus it rejects any complex expressions + * and only allows a few of selected operators that doesn't change the + * location. + */ + while (nops) { + switch (ops->atom) { + case DW_OP_stack_value: + case DW_OP_deref_size: + case DW_OP_deref: + case DW_OP_piece: + break; + default: + return false; + } + ops++; + nops--; + } + return true; +} +#endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT || HAVE_DWARF_CFI_SUPPORT */ + #ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT /** * die_get_var_innermost_scope - Get innermost scope range of given variable DIE @@ -1197,14 +1372,364 @@ int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf) 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) + +/* Interval parameters for __die_find_var_reg_cb() */ +struct find_var_data { + /* Target instruction address */ + Dwarf_Addr pc; + /* Target memory address (for global data) */ + Dwarf_Addr addr; + /* Target register */ + unsigned reg; + /* Access offset, set for global data */ + int offset; + /* True if the current register is the frame base */ + bool is_fbreg; +}; + +/* Max number of registers DW_OP_regN supports */ +#define DWARF_OP_DIRECT_REGS 32 + +static bool match_var_offset(Dwarf_Die *die_mem, struct find_var_data *data, + u64 addr_offset, u64 addr_type, bool is_pointer) +{ + Dwarf_Die type_die; + Dwarf_Word size; + + if (addr_offset == addr_type) { + /* Update offset relative to the start of the variable */ + data->offset = 0; + return true; + } + + if (addr_offset < addr_type) + return false; + + if (die_get_real_type(die_mem, &type_die) == NULL) + return false; + + if (is_pointer && dwarf_tag(&type_die) == DW_TAG_pointer_type) { + /* Get the target type of the pointer */ + if (die_get_real_type(&type_die, &type_die) == NULL) + return false; + } + + if (dwarf_aggregate_size(&type_die, &size) < 0) + return false; + + if (addr_offset >= addr_type + size) + return false; + + /* Update offset relative to the start of the variable */ + data->offset = addr_offset - addr_type; + return true; +} + +/* Only checks direct child DIEs in the given scope. */ +static int __die_find_var_reg_cb(Dwarf_Die *die_mem, void *arg) { - return -ENOTSUP; + struct find_var_data *data = arg; + int tag = dwarf_tag(die_mem); + ptrdiff_t off = 0; + Dwarf_Attribute attr; + Dwarf_Addr base, start, end; + Dwarf_Op *ops; + size_t nops; + + if (tag != DW_TAG_variable && tag != DW_TAG_formal_parameter) + return DIE_FIND_CB_SIBLING; + + if (dwarf_attr(die_mem, DW_AT_location, &attr) == NULL) + return DIE_FIND_CB_SIBLING; + + while ((off = dwarf_getlocations(&attr, off, &base, &start, &end, &ops, &nops)) > 0) { + /* Assuming the location list is sorted by address */ + if (end < data->pc) + continue; + if (start > data->pc) + break; + + /* Local variables accessed using frame base register */ + if (data->is_fbreg && ops->atom == DW_OP_fbreg && + check_allowed_ops(ops, nops) && + match_var_offset(die_mem, data, data->offset, ops->number, + /*is_pointer=*/false)) + return DIE_FIND_CB_END; + + /* Only match with a simple case */ + if (data->reg < DWARF_OP_DIRECT_REGS) { + /* pointer variables saved in a register 0 to 31 */ + if (ops->atom == (DW_OP_reg0 + data->reg) && + check_allowed_ops(ops, nops) && + match_var_offset(die_mem, data, data->offset, 0, + /*is_pointer=*/true)) + return DIE_FIND_CB_END; + + /* Local variables accessed by a register + offset */ + if (ops->atom == (DW_OP_breg0 + data->reg) && + check_allowed_ops(ops, nops) && + match_var_offset(die_mem, data, data->offset, ops->number, + /*is_pointer=*/false)) + return DIE_FIND_CB_END; + } else { + /* pointer variables saved in a register 32 or above */ + if (ops->atom == DW_OP_regx && ops->number == data->reg && + check_allowed_ops(ops, nops) && + match_var_offset(die_mem, data, data->offset, 0, + /*is_pointer=*/true)) + return DIE_FIND_CB_END; + + /* Local variables accessed by a register + offset */ + if (ops->atom == DW_OP_bregx && data->reg == ops->number && + check_allowed_ops(ops, nops) && + match_var_offset(die_mem, data, data->offset, ops->number2, + /*is_poitner=*/false)) + return DIE_FIND_CB_END; + } + } + return DIE_FIND_CB_SIBLING; } -#endif + +/** + * die_find_variable_by_reg - Find a variable saved in a register + * @sc_die: a scope DIE + * @pc: the program address to find + * @reg: the register number to find + * @poffset: pointer to offset, will be updated for fbreg case + * @is_fbreg: boolean value if the current register is the frame base + * @die_mem: a buffer to save the resulting DIE + * + * Find the variable DIE accessed by the given register. It'll update the @offset + * when the variable is in the stack. + */ +Dwarf_Die *die_find_variable_by_reg(Dwarf_Die *sc_die, Dwarf_Addr pc, int reg, + int *poffset, bool is_fbreg, + Dwarf_Die *die_mem) +{ + struct find_var_data data = { + .pc = pc, + .reg = reg, + .offset = *poffset, + .is_fbreg = is_fbreg, + }; + Dwarf_Die *result; + + result = die_find_child(sc_die, __die_find_var_reg_cb, &data, die_mem); + if (result) + *poffset = data.offset; + return result; +} + +/* Only checks direct child DIEs in the given scope */ +static int __die_find_var_addr_cb(Dwarf_Die *die_mem, void *arg) +{ + struct find_var_data *data = arg; + int tag = dwarf_tag(die_mem); + ptrdiff_t off = 0; + Dwarf_Attribute attr; + Dwarf_Addr base, start, end; + Dwarf_Op *ops; + size_t nops; + + if (tag != DW_TAG_variable) + return DIE_FIND_CB_SIBLING; + + if (dwarf_attr(die_mem, DW_AT_location, &attr) == NULL) + return DIE_FIND_CB_SIBLING; + + while ((off = dwarf_getlocations(&attr, off, &base, &start, &end, &ops, &nops)) > 0) { + if (ops->atom != DW_OP_addr) + continue; + + if (check_allowed_ops(ops, nops) && + match_var_offset(die_mem, data, data->addr, ops->number, + /*is_pointer=*/false)) + return DIE_FIND_CB_END; + } + return DIE_FIND_CB_SIBLING; +} + +/** + * die_find_variable_by_addr - Find variable located at given address + * @sc_die: a scope DIE + * @addr: the data address to find + * @die_mem: a buffer to save the resulting DIE + * @offset: the offset in the resulting type + * + * Find the variable DIE located at the given address (in PC-relative mode). + * This is usually for global variables. + */ +Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr addr, + Dwarf_Die *die_mem, int *offset) +{ + struct find_var_data data = { + .addr = addr, + }; + Dwarf_Die *result; + + result = die_find_child(sc_die, __die_find_var_addr_cb, &data, die_mem); + if (result) + *offset = data.offset; + return result; +} + +static int __die_collect_vars_cb(Dwarf_Die *die_mem, void *arg) +{ + struct die_var_type **var_types = arg; + Dwarf_Die type_die; + int tag = dwarf_tag(die_mem); + Dwarf_Attribute attr; + Dwarf_Addr base, start, end; + Dwarf_Op *ops; + size_t nops; + struct die_var_type *vt; + + if (tag != DW_TAG_variable && tag != DW_TAG_formal_parameter) + return DIE_FIND_CB_SIBLING; + + if (dwarf_attr(die_mem, DW_AT_location, &attr) == NULL) + return DIE_FIND_CB_SIBLING; + + /* + * Only collect the first location as it can reconstruct the + * remaining state by following the instructions. + * start = 0 means it covers the whole range. + */ + if (dwarf_getlocations(&attr, 0, &base, &start, &end, &ops, &nops) <= 0) + return DIE_FIND_CB_SIBLING; + + if (die_get_real_type(die_mem, &type_die) == NULL) + return DIE_FIND_CB_SIBLING; + + vt = malloc(sizeof(*vt)); + if (vt == NULL) + return DIE_FIND_CB_END; + + vt->die_off = dwarf_dieoffset(&type_die); + vt->addr = start; + vt->reg = reg_from_dwarf_op(ops); + vt->offset = offset_from_dwarf_op(ops); + vt->next = *var_types; + *var_types = vt; + + return DIE_FIND_CB_SIBLING; +} + +/** + * die_collect_vars - Save all variables and parameters + * @sc_die: a scope DIE + * @var_types: a pointer to save the resulting list + * + * Save all variables and parameters in the @sc_die and save them to @var_types. + * The @var_types is a singly-linked list containing type and location info. + * Actual type can be retrieved using dwarf_offdie() with 'die_off' later. + * + * Callers should free @var_types. + */ +void die_collect_vars(Dwarf_Die *sc_die, struct die_var_type **var_types) +{ + Dwarf_Die die_mem; + + die_find_child(sc_die, __die_collect_vars_cb, (void *)var_types, &die_mem); +} + +static int __die_collect_global_vars_cb(Dwarf_Die *die_mem, void *arg) +{ + struct die_var_type **var_types = arg; + Dwarf_Die type_die; + int tag = dwarf_tag(die_mem); + Dwarf_Attribute attr; + Dwarf_Addr base, start, end; + Dwarf_Op *ops; + size_t nops; + struct die_var_type *vt; + + if (tag != DW_TAG_variable) + return DIE_FIND_CB_SIBLING; + + if (dwarf_attr(die_mem, DW_AT_location, &attr) == NULL) + return DIE_FIND_CB_SIBLING; + + /* Only collect the location with an absolute address. */ + if (dwarf_getlocations(&attr, 0, &base, &start, &end, &ops, &nops) <= 0) + return DIE_FIND_CB_SIBLING; + + if (ops->atom != DW_OP_addr) + return DIE_FIND_CB_SIBLING; + + if (!check_allowed_ops(ops, nops)) + return DIE_FIND_CB_SIBLING; + + if (die_get_real_type(die_mem, &type_die) == NULL) + return DIE_FIND_CB_SIBLING; + + vt = malloc(sizeof(*vt)); + if (vt == NULL) + return DIE_FIND_CB_END; + + vt->die_off = dwarf_dieoffset(&type_die); + vt->addr = ops->number; + vt->reg = -1; + vt->offset = 0; + vt->next = *var_types; + *var_types = vt; + + return DIE_FIND_CB_SIBLING; +} + +/** + * die_collect_global_vars - Save all global variables + * @cu_die: a CU DIE + * @var_types: a pointer to save the resulting list + * + * Save all global variables in the @cu_die and save them to @var_types. + * The @var_types is a singly-linked list containing type and location info. + * Actual type can be retrieved using dwarf_offdie() with 'die_off' later. + * + * Callers should free @var_types. + */ +void die_collect_global_vars(Dwarf_Die *cu_die, struct die_var_type **var_types) +{ + Dwarf_Die die_mem; + + die_find_child(cu_die, __die_collect_global_vars_cb, (void *)var_types, &die_mem); +} +#endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */ + +#ifdef HAVE_DWARF_CFI_SUPPORT +/** + * die_get_cfa - Get frame base information + * @dwarf: a Dwarf info + * @pc: program address + * @preg: pointer for saved register + * @poffset: pointer for saved offset + * + * This function gets register and offset for CFA (Canonical Frame Address) + * by searching the CIE/FDE info. The CFA usually points to the start address + * of the current stack frame and local variables can be located using an offset + * from the CFA. The @preg and @poffset will be updated if it returns 0. + */ +int die_get_cfa(Dwarf *dwarf, u64 pc, int *preg, int *poffset) +{ + Dwarf_CFI *cfi; + Dwarf_Frame *frame = NULL; + Dwarf_Op *ops = NULL; + size_t nops; + + cfi = dwarf_getcfi(dwarf); + if (cfi == NULL) + return -1; + + if (!dwarf_cfi_addrframe(cfi, pc, &frame) && + !dwarf_frame_cfa(frame, &ops, &nops) && + check_allowed_ops(ops, nops)) { + *preg = reg_from_dwarf_op(ops); + *poffset = offset_from_dwarf_op(ops); + return 0; + } + return -1; +} +#endif /* HAVE_DWARF_CFI_SUPPORT */ /* * die_has_loclist - Check if DW_AT_location of @vr_die is a location list @@ -1384,3 +1909,169 @@ void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die, *entrypc = postprologue_addr; } + +/* Internal parameters for __die_find_scope_cb() */ +struct find_scope_data { + /* Target instruction address */ + Dwarf_Addr pc; + /* Number of scopes found [output] */ + int nr; + /* Array of scopes found, 0 for the outermost one. [output] */ + Dwarf_Die *scopes; +}; + +static int __die_find_scope_cb(Dwarf_Die *die_mem, void *arg) +{ + struct find_scope_data *data = arg; + + if (dwarf_haspc(die_mem, data->pc)) { + Dwarf_Die *tmp; + + tmp = realloc(data->scopes, (data->nr + 1) * sizeof(*tmp)); + if (tmp == NULL) + return DIE_FIND_CB_END; + + memcpy(tmp + data->nr, die_mem, sizeof(*die_mem)); + data->scopes = tmp; + data->nr++; + return DIE_FIND_CB_CHILD; + } + return DIE_FIND_CB_SIBLING; +} + +/** + * die_get_scopes - Return a list of scopes including the address + * @cu_die: a compile unit DIE + * @pc: the address to find + * @scopes: the array of DIEs for scopes (result) + * + * This function does the same as the dwarf_getscopes() but doesn't follow + * the origins of inlined functions. It returns the number of scopes saved + * in the @scopes argument. The outer scope will be saved first (index 0) and + * the last one is the innermost scope at the @pc. + */ +int die_get_scopes(Dwarf_Die *cu_die, Dwarf_Addr pc, Dwarf_Die **scopes) +{ + struct find_scope_data data = { + .pc = pc, + }; + Dwarf_Die die_mem; + + die_find_child(cu_die, __die_find_scope_cb, &data, &die_mem); + + *scopes = data.scopes; + return data.nr; +} + +static int __die_find_member_offset_cb(Dwarf_Die *die_mem, void *arg) +{ + Dwarf_Die type_die; + Dwarf_Word size, loc; + Dwarf_Word offset = (long)arg; + int tag = dwarf_tag(die_mem); + + if (tag != DW_TAG_member) + return DIE_FIND_CB_SIBLING; + + /* Unions might not have location */ + if (die_get_data_member_location(die_mem, &loc) < 0) + loc = 0; + + if (offset == loc) + return DIE_FIND_CB_END; + + if (die_get_real_type(die_mem, &type_die) == NULL) { + // TODO: add a pr_debug_dtp() later for this unlikely failure + return DIE_FIND_CB_SIBLING; + } + + if (dwarf_aggregate_size(&type_die, &size) < 0) + size = 0; + + if (loc < offset && offset < (loc + size)) + return DIE_FIND_CB_END; + + return DIE_FIND_CB_SIBLING; +} + +/** + * die_get_member_type - Return type info of struct member + * @type_die: a type DIE + * @offset: offset in the type + * @die_mem: a buffer to save the resulting DIE + * + * This function returns a type of a member in @type_die where it's located at + * @offset if it's a struct. For now, it just returns the first matching + * member in a union. For other types, it'd return the given type directly + * if it's within the size of the type or NULL otherwise. + */ +Dwarf_Die *die_get_member_type(Dwarf_Die *type_die, int offset, + Dwarf_Die *die_mem) +{ + Dwarf_Die *member; + Dwarf_Die mb_type; + int tag; + + tag = dwarf_tag(type_die); + /* If it's not a compound type, return the type directly */ + if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) { + Dwarf_Word size; + + if (dwarf_aggregate_size(type_die, &size) < 0) + size = 0; + + if ((unsigned)offset >= size) + return NULL; + + *die_mem = *type_die; + return die_mem; + } + + mb_type = *type_die; + /* TODO: Handle union types better? */ + while (tag == DW_TAG_structure_type || tag == DW_TAG_union_type) { + member = die_find_child(&mb_type, __die_find_member_offset_cb, + (void *)(long)offset, die_mem); + if (member == NULL) + return NULL; + + if (die_get_real_type(member, &mb_type) == NULL) + return NULL; + + tag = dwarf_tag(&mb_type); + + if (tag == DW_TAG_structure_type || tag == DW_TAG_union_type) { + Dwarf_Word loc; + + /* Update offset for the start of the member struct */ + if (die_get_data_member_location(member, &loc) == 0) + offset -= loc; + } + } + *die_mem = mb_type; + return die_mem; +} + +/** + * die_deref_ptr_type - Return type info for pointer access + * @ptr_die: a pointer type DIE + * @offset: access offset for the pointer + * @die_mem: a buffer to save the resulting DIE + * + * This function follows the pointer in @ptr_die with given @offset + * and saves the resulting type in @die_mem. If the pointer points + * a struct type, actual member at the offset would be returned. + */ +Dwarf_Die *die_deref_ptr_type(Dwarf_Die *ptr_die, int offset, + Dwarf_Die *die_mem) +{ + Dwarf_Die type_die; + + if (dwarf_tag(ptr_die) != DW_TAG_pointer_type) + return NULL; + + if (die_get_real_type(ptr_die, &type_die) == NULL) + return NULL; + + return die_get_member_type(&type_die, offset, die_mem); +} |