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-rw-r--r--tools/perf/util/dwarf-aux.c663
1 files changed, 663 insertions, 0 deletions
diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
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index 000000000000..fddf40f30d3e
--- /dev/null
+++ b/tools/perf/util/dwarf-aux.c
@@ -0,0 +1,663 @@
+/*
+ * dwarf-aux.c : libdw auxiliary interfaces
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#include <stdbool.h>
+#include "util.h"
+#include "debug.h"
+#include "dwarf-aux.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;
+}
+
+/**
+ * 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_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;
+}
+
+/**
+ * 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_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;
+}
+
+/**
+ * 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;
+};
+
+/* 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;
+
+ 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_inlinefunc - Search an inlined function at given address
+ * @cu_die: a CU 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 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;
+}
+
+/* Line walker internal parameters */
+struct __line_walk_param {
+ const char *fname;
+ 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;
+ int lineno;
+
+ if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
+ lineno = die_get_call_lineno(in_die);
+ if (lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
+ lw->retval = lw->callback(lw->fname, lineno, addr,
+ lw->data);
+ if (lw->retval != 0)
+ return DIE_FIND_CB_END;
+ }
+ }
+ return DIE_FIND_CB_SIBLING;
+}
+
+/* Walk on lines of blocks included in given DIE */
+static int __die_walk_funclines(Dwarf_Die *sp_die,
+ line_walk_callback_t callback, void *data)
+{
+ struct __line_walk_param lw = {
+ .callback = callback,
+ .data = data,
+ .retval = 0,
+ };
+ Dwarf_Die die_mem;
+ Dwarf_Addr addr;
+ int lineno;
+
+ /* Handle function declaration line */
+ lw.fname = dwarf_decl_file(sp_die);
+ if (lw.fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
+ dwarf_entrypc(sp_die, &addr) == 0) {
+ lw.retval = callback(lw.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;
+
+ lw->retval = __die_walk_funclines(sp_die, 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 or subprogram)
+ * @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;
+ int lineno, ret = 0;
+ Dwarf_Die die_mem, *cu_die;
+ size_t nlines, i;
+
+ /* Get the CU die */
+ if (dwarf_tag(rt_die) == DW_TAG_subprogram)
+ cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
+ else
+ cu_die = rt_die;
+ if (!cu_die) {
+ pr_debug2("Failed to get CU from subprogram\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;
+ }
+ /* 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) ||
+ die_find_inlinefunc(rt_die, addr, &die_mem))
+ continue;
+ /* 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)
+ ret = __die_walk_funclines(rt_die, callback, data);
+ else {
+ struct __line_walk_param param = {
+ .callback = callback,
+ .data = data,
+ .retval = 0,
+ };
+ dwarf_getfuncs(cu_die, __die_walk_culines_cb, &param, 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;
+ int tag;
+
+ tag = dwarf_tag(die_mem);
+ if ((tag == DW_TAG_formal_parameter ||
+ tag == DW_TAG_variable) &&
+ die_compare_name(die_mem, fvp->name))
+ 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) &&
+ die_compare_name(die_mem, name))
+ 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 buffer for result type name
+ * @len: a max-length of @buf
+ *
+ * Get the name of @vr_die and stores it to @buf. Return the actual length
+ * of type name if succeeded. Return -E2BIG if @len is not enough long, 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, char *buf, int len)
+{
+ Dwarf_Die type;
+ int tag, ret, ret2;
+ 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 */
+ ret = snprintf(buf, len, "(function_type)");
+ return (ret >= len) ? -E2BIG : ret;
+ } else {
+ if (!dwarf_diename(&type))
+ return -ENOENT;
+ if (tag == DW_TAG_union_type)
+ tmp = "union ";
+ else if (tag == DW_TAG_structure_type)
+ tmp = "struct ";
+ /* Write a base name */
+ ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
+ return (ret >= len) ? -E2BIG : ret;
+ }
+ ret = die_get_typename(&type, buf, len);
+ if (ret > 0) {
+ ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
+ ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
+ }
+ return ret;
+}
+
+/**
+ * die_get_varname - Get the name and type of given variable DIE
+ * @vr_die: a variable DIE
+ * @buf: a buffer for type and variable name
+ * @len: the max-length of @buf
+ *
+ * Get the name and type of @vr_die and stores it in @buf as "type\tname".
+ */
+int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
+{
+ int ret, ret2;
+
+ ret = die_get_typename(vr_die, buf, len);
+ if (ret < 0) {
+ pr_debug("Failed to get type, make it unknown.\n");
+ ret = snprintf(buf, len, "(unknown_type)");
+ }
+ if (ret > 0) {
+ ret2 = snprintf(buf + ret, len - ret, "\t%s",
+ dwarf_diename(vr_die));
+ ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
+ }
+ return ret;
+}
+
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