summaryrefslogtreecommitdiffstats
path: root/tools/perf/util/dwarf-aux.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/perf/util/dwarf-aux.c')
-rw-r--r--tools/perf/util/dwarf-aux.c1401
1 files changed, 1401 insertions, 0 deletions
diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
new file mode 100644
index 000000000..b125eaadc
--- /dev/null
+++ b/tools/perf/util/dwarf-aux.c
@@ -0,0 +1,1401 @@
+// 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);
+}
+
+/* Unlike dwarf_getsrc_die(), cu_getsrc_die() only returns statement line */
+static Dwarf_Line *cu_getsrc_die(Dwarf_Die *cu_die, Dwarf_Addr addr)
+{
+ Dwarf_Addr laddr;
+ Dwarf_Lines *lines;
+ Dwarf_Line *line;
+ size_t nlines, l, u, n;
+ bool flag;
+
+ if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0 ||
+ nlines == 0)
+ return NULL;
+
+ /* Lines are sorted by address, use binary search */
+ l = 0; u = nlines - 1;
+ while (l < u) {
+ n = u - (u - l) / 2;
+ line = dwarf_onesrcline(lines, n);
+ if (!line || dwarf_lineaddr(line, &laddr) != 0)
+ return NULL;
+ if (addr < laddr)
+ u = n - 1;
+ else
+ l = n;
+ }
+ /* Going backward to find the lowest line */
+ do {
+ line = dwarf_onesrcline(lines, --l);
+ if (!line || dwarf_lineaddr(line, &laddr) != 0)
+ return NULL;
+ } while (laddr == addr);
+ l++;
+ /* Going forward to find the statement line */
+ do {
+ line = dwarf_onesrcline(lines, l++);
+ if (!line || dwarf_lineaddr(line, &laddr) != 0 ||
+ dwarf_linebeginstatement(line, &flag) != 0)
+ return NULL;
+ if (laddr > addr)
+ return NULL;
+ } while (!flag);
+
+ return line;
+}
+
+/**
+ * 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, Dwarf_Addr addr,
+ const char **fname, int *lineno)
+{
+ Dwarf_Line *line;
+ Dwarf_Die die_mem;
+ Dwarf_Addr faddr;
+
+ if (die_find_realfunc(cu_die, addr, &die_mem)
+ && die_entrypc(&die_mem, &faddr) == 0 &&
+ faddr == addr) {
+ *fname = dwarf_decl_file(&die_mem);
+ dwarf_decl_line(&die_mem, lineno);
+ goto out;
+ }
+
+ line = cu_getsrc_die(cu_die, addr);
+ if (line && dwarf_lineno(line, lineno) == 0) {
+ *fname = dwarf_linesrc(line, NULL, NULL);
+ if (!*fname)
+ /* line number is useless without filename */
+ *lineno = 0;
+ }
+
+out:
+ 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 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)
+{
+ 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_integrate(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_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;
+ Dwarf_Addr addr = 0;
+
+ if (dwarf_tag(dw_die) != DW_TAG_subprogram)
+ return false;
+
+ 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;
+}
+
+/**
+ * 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_Word idx;
+
+ if (die_get_attr_udata(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_Word idx;
+
+ if (die_get_attr_udata(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
+ * 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 *),
+ 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, &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;
+ 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 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_const_value, &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;
+}