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-rw-r--r--tools/perf/util/probe-finder.c2064
1 files changed, 2064 insertions, 0 deletions
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
new file mode 100644
index 00000000..3b9d0b80
--- /dev/null
+++ b/tools/perf/util/probe-finder.c
@@ -0,0 +1,2064 @@
+/*
+ * probe-finder.c : C expression to kprobe event converter
+ *
+ * Written by Masami Hiramatsu <mhiramat@redhat.com>
+ *
+ * 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 <sys/utsname.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <ctype.h>
+#include <dwarf-regs.h>
+
+#include <linux/bitops.h>
+#include "event.h"
+#include "debug.h"
+#include "util.h"
+#include "symbol.h"
+#include "probe-finder.h"
+
+/* Kprobe tracer basic type is up to u64 */
+#define MAX_BASIC_TYPE_BITS 64
+
+/*
+ * Compare the tail of two strings.
+ * Return 0 if whole of either string is same as another's tail part.
+ */
+static int strtailcmp(const char *s1, const char *s2)
+{
+ int i1 = strlen(s1);
+ int i2 = strlen(s2);
+ while (--i1 >= 0 && --i2 >= 0) {
+ if (s1[i1] != s2[i2])
+ return s1[i1] - s2[i2];
+ }
+ return 0;
+}
+
+/* Line number list operations */
+
+/* Add a line to line number list */
+static int line_list__add_line(struct list_head *head, int line)
+{
+ struct line_node *ln;
+ struct list_head *p;
+
+ /* Reverse search, because new line will be the last one */
+ list_for_each_entry_reverse(ln, head, list) {
+ if (ln->line < line) {
+ p = &ln->list;
+ goto found;
+ } else if (ln->line == line) /* Already exist */
+ return 1;
+ }
+ /* List is empty, or the smallest entry */
+ p = head;
+found:
+ pr_debug("line list: add a line %u\n", line);
+ ln = zalloc(sizeof(struct line_node));
+ if (ln == NULL)
+ return -ENOMEM;
+ ln->line = line;
+ INIT_LIST_HEAD(&ln->list);
+ list_add(&ln->list, p);
+ return 0;
+}
+
+/* Check if the line in line number list */
+static int line_list__has_line(struct list_head *head, int line)
+{
+ struct line_node *ln;
+
+ /* Reverse search, because new line will be the last one */
+ list_for_each_entry(ln, head, list)
+ if (ln->line == line)
+ return 1;
+
+ return 0;
+}
+
+/* Init line number list */
+static void line_list__init(struct list_head *head)
+{
+ INIT_LIST_HEAD(head);
+}
+
+/* Free line number list */
+static void line_list__free(struct list_head *head)
+{
+ struct line_node *ln;
+ while (!list_empty(head)) {
+ ln = list_first_entry(head, struct line_node, list);
+ list_del(&ln->list);
+ free(ln);
+ }
+}
+
+/* Dwarf FL wrappers */
+static char *debuginfo_path; /* Currently dummy */
+
+static const Dwfl_Callbacks offline_callbacks = {
+ .find_debuginfo = dwfl_standard_find_debuginfo,
+ .debuginfo_path = &debuginfo_path,
+
+ .section_address = dwfl_offline_section_address,
+
+ /* We use this table for core files too. */
+ .find_elf = dwfl_build_id_find_elf,
+};
+
+/* Get a Dwarf from offline image */
+static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias)
+{
+ Dwfl_Module *mod;
+ Dwarf *dbg = NULL;
+
+ if (!dwflp)
+ return NULL;
+
+ *dwflp = dwfl_begin(&offline_callbacks);
+ if (!*dwflp)
+ return NULL;
+
+ mod = dwfl_report_offline(*dwflp, "", "", fd);
+ if (!mod)
+ goto error;
+
+ dbg = dwfl_module_getdwarf(mod, bias);
+ if (!dbg) {
+error:
+ dwfl_end(*dwflp);
+ *dwflp = NULL;
+ }
+ return dbg;
+}
+
+#if _ELFUTILS_PREREQ(0, 148)
+/* This method is buggy if elfutils is older than 0.148 */
+static int __linux_kernel_find_elf(Dwfl_Module *mod,
+ void **userdata,
+ const char *module_name,
+ Dwarf_Addr base,
+ char **file_name, Elf **elfp)
+{
+ int fd;
+ const char *path = kernel_get_module_path(module_name);
+
+ pr_debug2("Use file %s for %s\n", path, module_name);
+ if (path) {
+ fd = open(path, O_RDONLY);
+ if (fd >= 0) {
+ *file_name = strdup(path);
+ return fd;
+ }
+ }
+ /* If failed, try to call standard method */
+ return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
+ file_name, elfp);
+}
+
+static const Dwfl_Callbacks kernel_callbacks = {
+ .find_debuginfo = dwfl_standard_find_debuginfo,
+ .debuginfo_path = &debuginfo_path,
+
+ .find_elf = __linux_kernel_find_elf,
+ .section_address = dwfl_linux_kernel_module_section_address,
+};
+
+/* Get a Dwarf from live kernel image */
+static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp,
+ Dwarf_Addr *bias)
+{
+ Dwarf *dbg;
+
+ if (!dwflp)
+ return NULL;
+
+ *dwflp = dwfl_begin(&kernel_callbacks);
+ if (!*dwflp)
+ return NULL;
+
+ /* Load the kernel dwarves: Don't care the result here */
+ dwfl_linux_kernel_report_kernel(*dwflp);
+ dwfl_linux_kernel_report_modules(*dwflp);
+
+ dbg = dwfl_addrdwarf(*dwflp, addr, bias);
+ /* Here, check whether we could get a real dwarf */
+ if (!dbg) {
+ pr_debug("Failed to find kernel dwarf at %lx\n",
+ (unsigned long)addr);
+ dwfl_end(*dwflp);
+ *dwflp = NULL;
+ }
+ return dbg;
+}
+#else
+/* With older elfutils, this just support kernel module... */
+static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr __used, Dwfl **dwflp,
+ Dwarf_Addr *bias)
+{
+ int fd;
+ const char *path = kernel_get_module_path("kernel");
+
+ if (!path) {
+ pr_err("Failed to find vmlinux path\n");
+ return NULL;
+ }
+
+ pr_debug2("Use file %s for debuginfo\n", path);
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return NULL;
+
+ return dwfl_init_offline_dwarf(fd, dwflp, bias);
+}
+#endif
+
+/* Dwarf wrappers */
+
+/* Find the realpath of the target file. */
+static 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;
+}
+
+/* Get DW_AT_comp_dir (should be NULL with older gcc) */
+static 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);
+}
+
+/* Get a line number and file name for given address */
+static int cu_find_lineinfo(Dwarf_Die *cudie, unsigned long addr,
+ const char **fname, int *lineno)
+{
+ Dwarf_Line *line;
+ Dwarf_Addr laddr;
+
+ line = dwarf_getsrc_die(cudie, (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;
+}
+
+/* Compare diename and tname */
+static 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;
+}
+
+/* Get callsite line number of inline-function instance */
+static 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;
+}
+
+/* Get type die */
+static 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;
+}
+
+/* Get a type die, but skip qualifiers and typedef */
+static 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;
+}
+
+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;
+}
+
+static 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);
+}
+
+static int die_get_byte_size(Dwarf_Die *tp_die)
+{
+ Dwarf_Word ret;
+
+ if (die_get_attr_udata(tp_die, DW_AT_byte_size, &ret))
+ return 0;
+
+ return (int)ret;
+}
+
+static int die_get_bit_size(Dwarf_Die *tp_die)
+{
+ Dwarf_Word ret;
+
+ if (die_get_attr_udata(tp_die, DW_AT_bit_size, &ret))
+ return 0;
+
+ return (int)ret;
+}
+
+static int die_get_bit_offset(Dwarf_Die *tp_die)
+{
+ Dwarf_Word ret;
+
+ if (die_get_attr_udata(tp_die, DW_AT_bit_offset, &ret))
+ return 0;
+
+ return (int)ret;
+}
+
+/* Get data_member_location offset */
+static 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;
+}
+
+/* Return values for die_find callbacks */
+enum {
+ DIE_FIND_CB_FOUND = 0, /* End of Search */
+ DIE_FIND_CB_CHILD = 1, /* Search only children */
+ DIE_FIND_CB_SIBLING = 2, /* Search only siblings */
+ DIE_FIND_CB_CONTINUE = 3, /* Search children and siblings */
+};
+
+/* Search a child die */
+static 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_FOUND)
+ 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_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;
+}
+
+/* Search a real subprogram including this line, */
+static Dwarf_Die *die_find_real_subprogram(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_FOUND;
+
+ return DIE_FIND_CB_CONTINUE;
+}
+
+/* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
+static 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;
+}
+
+/* Walker on lines (Note: line number will not be sorted) */
+typedef int (* line_walk_handler_t) (const char *fname, int lineno,
+ Dwarf_Addr addr, void *data);
+
+struct __line_walk_param {
+ const char *fname;
+ line_walk_handler_t handler;
+ 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->handler(lw->fname, lineno, addr,
+ lw->data);
+ if (lw->retval != 0)
+ return DIE_FIND_CB_FOUND;
+ }
+ }
+ 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_handler_t handler, void *data)
+{
+ struct __line_walk_param lw = {
+ .handler = handler,
+ .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 = handler(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->handler, lw->data);
+ if (lw->retval != 0)
+ return DWARF_CB_ABORT;
+
+ return DWARF_CB_OK;
+}
+
+/*
+ * Walk on lines inside given PDIE. If the PDIE is subprogram, walk only on
+ * the lines inside the subprogram, otherwise PDIE must be a CU DIE.
+ */
+static int die_walk_lines(Dwarf_Die *pdie, line_walk_handler_t handler,
+ 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(pdie) == DW_TAG_subprogram)
+ cu_die = dwarf_diecu(pdie, &die_mem, NULL, NULL);
+ else
+ cu_die = pdie;
+ 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 (pdie != cu_die)
+ /*
+ * Address filtering
+ * The line is included in given function, and
+ * no inline block includes it.
+ */
+ if (!dwarf_haspc(pdie, addr) ||
+ die_find_inlinefunc(pdie, addr, &die_mem))
+ continue;
+ /* Get source line */
+ fname = dwarf_linesrc(line, NULL, NULL);
+
+ ret = handler(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 (pdie != cu_die)
+ ret = __die_walk_funclines(pdie, handler, data);
+ else {
+ struct __line_walk_param param = {
+ .handler = handler,
+ .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_FOUND;
+
+ if (dwarf_haspc(die_mem, fvp->addr))
+ return DIE_FIND_CB_CONTINUE;
+ else
+ return DIE_FIND_CB_SIBLING;
+}
+
+/* Find a variable called 'name' at given address */
+static 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_FOUND;
+
+ return DIE_FIND_CB_SIBLING;
+}
+
+/* Find a member called 'name' */
+static 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);
+}
+
+/* Get the name of given variable DIE */
+static 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;
+}
+
+/* Get the name and type of given variable DIE, stored as "type\tname" */
+static 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;
+}
+
+/*
+ * Probe finder related functions
+ */
+
+static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
+{
+ struct probe_trace_arg_ref *ref;
+ ref = zalloc(sizeof(struct probe_trace_arg_ref));
+ if (ref != NULL)
+ ref->offset = offs;
+ return ref;
+}
+
+/*
+ * Convert a location into trace_arg.
+ * If tvar == NULL, this just checks variable can be converted.
+ */
+static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
+ Dwarf_Op *fb_ops,
+ struct probe_trace_arg *tvar)
+{
+ Dwarf_Attribute attr;
+ Dwarf_Op *op;
+ size_t nops;
+ unsigned int regn;
+ Dwarf_Word offs = 0;
+ bool ref = false;
+ const char *regs;
+ int ret;
+
+ if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
+ goto static_var;
+
+ /* TODO: handle more than 1 exprs */
+ if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
+ dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
+ nops == 0) {
+ /* TODO: Support const_value */
+ return -ENOENT;
+ }
+
+ if (op->atom == DW_OP_addr) {
+static_var:
+ if (!tvar)
+ return 0;
+ /* Static variables on memory (not stack), make @varname */
+ ret = strlen(dwarf_diename(vr_die));
+ tvar->value = zalloc(ret + 2);
+ if (tvar->value == NULL)
+ return -ENOMEM;
+ snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
+ tvar->ref = alloc_trace_arg_ref((long)offs);
+ if (tvar->ref == NULL)
+ return -ENOMEM;
+ return 0;
+ }
+
+ /* If this is based on frame buffer, set the offset */
+ if (op->atom == DW_OP_fbreg) {
+ if (fb_ops == NULL)
+ return -ENOTSUP;
+ ref = true;
+ offs = op->number;
+ op = &fb_ops[0];
+ }
+
+ if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
+ regn = op->atom - DW_OP_breg0;
+ offs += op->number;
+ ref = true;
+ } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
+ regn = op->atom - DW_OP_reg0;
+ } else if (op->atom == DW_OP_bregx) {
+ regn = op->number;
+ offs += op->number2;
+ ref = true;
+ } else if (op->atom == DW_OP_regx) {
+ regn = op->number;
+ } else {
+ pr_debug("DW_OP %x is not supported.\n", op->atom);
+ return -ENOTSUP;
+ }
+
+ if (!tvar)
+ return 0;
+
+ regs = get_arch_regstr(regn);
+ if (!regs) {
+ /* This should be a bug in DWARF or this tool */
+ pr_warning("Mapping for the register number %u "
+ "missing on this architecture.\n", regn);
+ return -ERANGE;
+ }
+
+ tvar->value = strdup(regs);
+ if (tvar->value == NULL)
+ return -ENOMEM;
+
+ if (ref) {
+ tvar->ref = alloc_trace_arg_ref((long)offs);
+ if (tvar->ref == NULL)
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+#define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
+
+static int convert_variable_type(Dwarf_Die *vr_die,
+ struct probe_trace_arg *tvar,
+ const char *cast)
+{
+ struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
+ Dwarf_Die type;
+ char buf[16];
+ int ret;
+
+ /* TODO: check all types */
+ if (cast && strcmp(cast, "string") != 0) {
+ /* Non string type is OK */
+ tvar->type = strdup(cast);
+ return (tvar->type == NULL) ? -ENOMEM : 0;
+ }
+
+ if (die_get_bit_size(vr_die) != 0) {
+ /* This is a bitfield */
+ ret = snprintf(buf, 16, "b%d@%d/%zd", die_get_bit_size(vr_die),
+ die_get_bit_offset(vr_die),
+ BYTES_TO_BITS(die_get_byte_size(vr_die)));
+ goto formatted;
+ }
+
+ if (die_get_real_type(vr_die, &type) == NULL) {
+ pr_warning("Failed to get a type information of %s.\n",
+ dwarf_diename(vr_die));
+ return -ENOENT;
+ }
+
+ pr_debug("%s type is %s.\n",
+ dwarf_diename(vr_die), dwarf_diename(&type));
+
+ if (cast && strcmp(cast, "string") == 0) { /* String type */
+ ret = dwarf_tag(&type);
+ if (ret != DW_TAG_pointer_type &&
+ ret != DW_TAG_array_type) {
+ pr_warning("Failed to cast into string: "
+ "%s(%s) is not a pointer nor array.\n",
+ dwarf_diename(vr_die), dwarf_diename(&type));
+ return -EINVAL;
+ }
+ if (ret == DW_TAG_pointer_type) {
+ if (die_get_real_type(&type, &type) == NULL) {
+ pr_warning("Failed to get a type"
+ " information.\n");
+ return -ENOENT;
+ }
+ while (*ref_ptr)
+ ref_ptr = &(*ref_ptr)->next;
+ /* Add new reference with offset +0 */
+ *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
+ if (*ref_ptr == NULL) {
+ pr_warning("Out of memory error\n");
+ return -ENOMEM;
+ }
+ }
+ if (!die_compare_name(&type, "char") &&
+ !die_compare_name(&type, "unsigned char")) {
+ pr_warning("Failed to cast into string: "
+ "%s is not (unsigned) char *.\n",
+ dwarf_diename(vr_die));
+ return -EINVAL;
+ }
+ tvar->type = strdup(cast);
+ return (tvar->type == NULL) ? -ENOMEM : 0;
+ }
+
+ ret = BYTES_TO_BITS(die_get_byte_size(&type));
+ if (!ret)
+ /* No size ... try to use default type */
+ return 0;
+
+ /* Check the bitwidth */
+ if (ret > MAX_BASIC_TYPE_BITS) {
+ pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
+ dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
+ ret = MAX_BASIC_TYPE_BITS;
+ }
+ ret = snprintf(buf, 16, "%c%d",
+ die_is_signed_type(&type) ? 's' : 'u', ret);
+
+formatted:
+ if (ret < 0 || ret >= 16) {
+ if (ret >= 16)
+ ret = -E2BIG;
+ pr_warning("Failed to convert variable type: %s\n",
+ strerror(-ret));
+ return ret;
+ }
+ tvar->type = strdup(buf);
+ if (tvar->type == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
+ struct perf_probe_arg_field *field,
+ struct probe_trace_arg_ref **ref_ptr,
+ Dwarf_Die *die_mem)
+{
+ struct probe_trace_arg_ref *ref = *ref_ptr;
+ Dwarf_Die type;
+ Dwarf_Word offs;
+ int ret, tag;
+
+ pr_debug("converting %s in %s\n", field->name, varname);
+ if (die_get_real_type(vr_die, &type) == NULL) {
+ pr_warning("Failed to get the type of %s.\n", varname);
+ return -ENOENT;
+ }
+ pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
+ tag = dwarf_tag(&type);
+
+ if (field->name[0] == '[' &&
+ (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
+ if (field->next)
+ /* Save original type for next field */
+ memcpy(die_mem, &type, sizeof(*die_mem));
+ /* Get the type of this array */
+ if (die_get_real_type(&type, &type) == NULL) {
+ pr_warning("Failed to get the type of %s.\n", varname);
+ return -ENOENT;
+ }
+ pr_debug2("Array real type: (%x)\n",
+ (unsigned)dwarf_dieoffset(&type));
+ if (tag == DW_TAG_pointer_type) {
+ ref = zalloc(sizeof(struct probe_trace_arg_ref));
+ if (ref == NULL)
+ return -ENOMEM;
+ if (*ref_ptr)
+ (*ref_ptr)->next = ref;
+ else
+ *ref_ptr = ref;
+ }
+ ref->offset += die_get_byte_size(&type) * field->index;
+ if (!field->next)
+ /* Save vr_die for converting types */
+ memcpy(die_mem, vr_die, sizeof(*die_mem));
+ goto next;
+ } else if (tag == DW_TAG_pointer_type) {
+ /* Check the pointer and dereference */
+ if (!field->ref) {
+ pr_err("Semantic error: %s must be referred by '->'\n",
+ field->name);
+ return -EINVAL;
+ }
+ /* Get the type pointed by this pointer */
+ if (die_get_real_type(&type, &type) == NULL) {
+ pr_warning("Failed to get the type of %s.\n", varname);
+ return -ENOENT;
+ }
+ /* Verify it is a data structure */
+ if (dwarf_tag(&type) != DW_TAG_structure_type) {
+ pr_warning("%s is not a data structure.\n", varname);
+ return -EINVAL;
+ }
+
+ ref = zalloc(sizeof(struct probe_trace_arg_ref));
+ if (ref == NULL)
+ return -ENOMEM;
+ if (*ref_ptr)
+ (*ref_ptr)->next = ref;
+ else
+ *ref_ptr = ref;
+ } else {
+ /* Verify it is a data structure */
+ if (tag != DW_TAG_structure_type) {
+ pr_warning("%s is not a data structure.\n", varname);
+ return -EINVAL;
+ }
+ if (field->name[0] == '[') {
+ pr_err("Semantic error: %s is not a pointor"
+ " nor array.\n", varname);
+ return -EINVAL;
+ }
+ if (field->ref) {
+ pr_err("Semantic error: %s must be referred by '.'\n",
+ field->name);
+ return -EINVAL;
+ }
+ if (!ref) {
+ pr_warning("Structure on a register is not "
+ "supported yet.\n");
+ return -ENOTSUP;
+ }
+ }
+
+ if (die_find_member(&type, field->name, die_mem) == NULL) {
+ pr_warning("%s(tyep:%s) has no member %s.\n", varname,
+ dwarf_diename(&type), field->name);
+ return -EINVAL;
+ }
+
+ /* Get the offset of the field */
+ ret = die_get_data_member_location(die_mem, &offs);
+ if (ret < 0) {
+ pr_warning("Failed to get the offset of %s.\n", field->name);
+ return ret;
+ }
+ ref->offset += (long)offs;
+
+next:
+ /* Converting next field */
+ if (field->next)
+ return convert_variable_fields(die_mem, field->name,
+ field->next, &ref, die_mem);
+ else
+ return 0;
+}
+
+/* Show a variables in kprobe event format */
+static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
+{
+ Dwarf_Die die_mem;
+ int ret;
+
+ pr_debug("Converting variable %s into trace event.\n",
+ dwarf_diename(vr_die));
+
+ ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
+ pf->tvar);
+ if (ret == -ENOENT)
+ pr_err("Failed to find the location of %s at this address.\n"
+ " Perhaps, it has been optimized out.\n", pf->pvar->var);
+ else if (ret == -ENOTSUP)
+ pr_err("Sorry, we don't support this variable location yet.\n");
+ else if (pf->pvar->field) {
+ ret = convert_variable_fields(vr_die, pf->pvar->var,
+ pf->pvar->field, &pf->tvar->ref,
+ &die_mem);
+ vr_die = &die_mem;
+ }
+ if (ret == 0)
+ ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
+ /* *expr will be cached in libdw. Don't free it. */
+ return ret;
+}
+
+/* Find a variable in a subprogram die */
+static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
+{
+ Dwarf_Die vr_die, *scopes;
+ char buf[32], *ptr;
+ int ret, nscopes;
+
+ if (!is_c_varname(pf->pvar->var)) {
+ /* Copy raw parameters */
+ pf->tvar->value = strdup(pf->pvar->var);
+ if (pf->tvar->value == NULL)
+ return -ENOMEM;
+ if (pf->pvar->type) {
+ pf->tvar->type = strdup(pf->pvar->type);
+ if (pf->tvar->type == NULL)
+ return -ENOMEM;
+ }
+ if (pf->pvar->name) {
+ pf->tvar->name = strdup(pf->pvar->name);
+ if (pf->tvar->name == NULL)
+ return -ENOMEM;
+ } else
+ pf->tvar->name = NULL;
+ return 0;
+ }
+
+ if (pf->pvar->name)
+ pf->tvar->name = strdup(pf->pvar->name);
+ else {
+ ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
+ if (ret < 0)
+ return ret;
+ ptr = strchr(buf, ':'); /* Change type separator to _ */
+ if (ptr)
+ *ptr = '_';
+ pf->tvar->name = strdup(buf);
+ }
+ if (pf->tvar->name == NULL)
+ return -ENOMEM;
+
+ pr_debug("Searching '%s' variable in context.\n",
+ pf->pvar->var);
+ /* Search child die for local variables and parameters. */
+ if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
+ ret = convert_variable(&vr_die, pf);
+ else {
+ /* Search upper class */
+ nscopes = dwarf_getscopes_die(sp_die, &scopes);
+ while (nscopes-- > 1) {
+ pr_debug("Searching variables in %s\n",
+ dwarf_diename(&scopes[nscopes]));
+ /* We should check this scope, so give dummy address */
+ if (die_find_variable_at(&scopes[nscopes],
+ pf->pvar->var, 0,
+ &vr_die)) {
+ ret = convert_variable(&vr_die, pf);
+ goto found;
+ }
+ }
+ if (scopes)
+ free(scopes);
+ ret = -ENOENT;
+ }
+found:
+ if (ret < 0)
+ pr_warning("Failed to find '%s' in this function.\n",
+ pf->pvar->var);
+ return ret;
+}
+
+/* Convert subprogram DIE to trace point */
+static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
+ bool retprobe, struct probe_trace_point *tp)
+{
+ Dwarf_Addr eaddr;
+ const char *name;
+
+ /* Copy the name of probe point */
+ name = dwarf_diename(sp_die);
+ if (name) {
+ if (dwarf_entrypc(sp_die, &eaddr) != 0) {
+ pr_warning("Failed to get entry address of %s\n",
+ dwarf_diename(sp_die));
+ return -ENOENT;
+ }
+ tp->symbol = strdup(name);
+ if (tp->symbol == NULL)
+ return -ENOMEM;
+ tp->offset = (unsigned long)(paddr - eaddr);
+ } else
+ /* This function has no name. */
+ tp->offset = (unsigned long)paddr;
+
+ /* Return probe must be on the head of a subprogram */
+ if (retprobe) {
+ if (eaddr != paddr) {
+ pr_warning("Return probe must be on the head of"
+ " a real function.\n");
+ return -EINVAL;
+ }
+ tp->retprobe = true;
+ }
+
+ return 0;
+}
+
+/* Call probe_finder callback with real subprogram DIE */
+static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
+{
+ Dwarf_Die die_mem;
+ Dwarf_Attribute fb_attr;
+ size_t nops;
+ int ret;
+
+ /* If no real subprogram, find a real one */
+ if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
+ sp_die = die_find_real_subprogram(&pf->cu_die,
+ pf->addr, &die_mem);
+ if (!sp_die) {
+ pr_warning("Failed to find probe point in any "
+ "functions.\n");
+ return -ENOENT;
+ }
+ }
+
+ /* Get the frame base attribute/ops */
+ dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
+ ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
+ if (ret <= 0 || nops == 0) {
+ pf->fb_ops = NULL;
+#if _ELFUTILS_PREREQ(0, 142)
+ } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
+ pf->cfi != NULL) {
+ Dwarf_Frame *frame;
+ if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
+ dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
+ pr_warning("Failed to get call frame on 0x%jx\n",
+ (uintmax_t)pf->addr);
+ return -ENOENT;
+ }
+#endif
+ }
+
+ /* Call finder's callback handler */
+ ret = pf->callback(sp_die, pf);
+
+ /* *pf->fb_ops will be cached in libdw. Don't free it. */
+ pf->fb_ops = NULL;
+
+ return ret;
+}
+
+static int probe_point_line_walker(const char *fname, int lineno,
+ Dwarf_Addr addr, void *data)
+{
+ struct probe_finder *pf = data;
+ int ret;
+
+ if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
+ return 0;
+
+ pf->addr = addr;
+ ret = call_probe_finder(NULL, pf);
+
+ /* Continue if no error, because the line will be in inline function */
+ return ret < 0 ? ret : 0;
+}
+
+/* Find probe point from its line number */
+static int find_probe_point_by_line(struct probe_finder *pf)
+{
+ return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
+}
+
+/* Find lines which match lazy pattern */
+static int find_lazy_match_lines(struct list_head *head,
+ const char *fname, const char *pat)
+{
+ FILE *fp;
+ char *line = NULL;
+ size_t line_len;
+ ssize_t len;
+ int count = 0, linenum = 1;
+
+ fp = fopen(fname, "r");
+ if (!fp) {
+ pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
+ return -errno;
+ }
+
+ while ((len = getline(&line, &line_len, fp)) > 0) {
+
+ if (line[len - 1] == '\n')
+ line[len - 1] = '\0';
+
+ if (strlazymatch(line, pat)) {
+ line_list__add_line(head, linenum);
+ count++;
+ }
+ linenum++;
+ }
+
+ if (ferror(fp))
+ count = -errno;
+ free(line);
+ fclose(fp);
+
+ if (count == 0)
+ pr_debug("No matched lines found in %s.\n", fname);
+ return count;
+}
+
+static int probe_point_lazy_walker(const char *fname, int lineno,
+ Dwarf_Addr addr, void *data)
+{
+ struct probe_finder *pf = data;
+ int ret;
+
+ if (!line_list__has_line(&pf->lcache, lineno) ||
+ strtailcmp(fname, pf->fname) != 0)
+ return 0;
+
+ pr_debug("Probe line found: line:%d addr:0x%llx\n",
+ lineno, (unsigned long long)addr);
+ pf->addr = addr;
+ ret = call_probe_finder(NULL, pf);
+
+ /*
+ * Continue if no error, because the lazy pattern will match
+ * to other lines
+ */
+ return ret < 0 ? ret : 0;
+}
+
+/* Find probe points from lazy pattern */
+static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
+{
+ int ret = 0;
+
+ if (list_empty(&pf->lcache)) {
+ /* Matching lazy line pattern */
+ ret = find_lazy_match_lines(&pf->lcache, pf->fname,
+ pf->pev->point.lazy_line);
+ if (ret <= 0)
+ return ret;
+ }
+
+ return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
+}
+
+/* Callback parameter with return value */
+struct dwarf_callback_param {
+ void *data;
+ int retval;
+};
+
+static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
+{
+ struct dwarf_callback_param *param = data;
+ struct probe_finder *pf = param->data;
+ struct perf_probe_point *pp = &pf->pev->point;
+ Dwarf_Addr addr;
+
+ if (pp->lazy_line)
+ param->retval = find_probe_point_lazy(in_die, pf);
+ else {
+ /* Get probe address */
+ if (dwarf_entrypc(in_die, &addr) != 0) {
+ pr_warning("Failed to get entry address of %s.\n",
+ dwarf_diename(in_die));
+ param->retval = -ENOENT;
+ return DWARF_CB_ABORT;
+ }
+ pf->addr = addr;
+ pf->addr += pp->offset;
+ pr_debug("found inline addr: 0x%jx\n",
+ (uintmax_t)pf->addr);
+
+ param->retval = call_probe_finder(in_die, pf);
+ if (param->retval < 0)
+ return DWARF_CB_ABORT;
+ }
+
+ return DWARF_CB_OK;
+}
+
+/* Search function from function name */
+static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
+{
+ struct dwarf_callback_param *param = data;
+ struct probe_finder *pf = param->data;
+ struct perf_probe_point *pp = &pf->pev->point;
+
+ /* Check tag and diename */
+ if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
+ !die_compare_name(sp_die, pp->function))
+ return DWARF_CB_OK;
+
+ /* Check declared file */
+ if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
+ return DWARF_CB_OK;
+
+ pf->fname = dwarf_decl_file(sp_die);
+ if (pp->line) { /* Function relative line */
+ dwarf_decl_line(sp_die, &pf->lno);
+ pf->lno += pp->line;
+ param->retval = find_probe_point_by_line(pf);
+ } else if (!dwarf_func_inline(sp_die)) {
+ /* Real function */
+ if (pp->lazy_line)
+ param->retval = find_probe_point_lazy(sp_die, pf);
+ else {
+ if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
+ pr_warning("Failed to get entry address of "
+ "%s.\n", dwarf_diename(sp_die));
+ param->retval = -ENOENT;
+ return DWARF_CB_ABORT;
+ }
+ pf->addr += pp->offset;
+ /* TODO: Check the address in this function */
+ param->retval = call_probe_finder(sp_die, pf);
+ }
+ } else {
+ struct dwarf_callback_param _param = {.data = (void *)pf,
+ .retval = 0};
+ /* Inlined function: search instances */
+ dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
+ &_param);
+ param->retval = _param.retval;
+ }
+
+ return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
+}
+
+static int find_probe_point_by_func(struct probe_finder *pf)
+{
+ struct dwarf_callback_param _param = {.data = (void *)pf,
+ .retval = 0};
+ dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
+ return _param.retval;
+}
+
+struct pubname_callback_param {
+ char *function;
+ char *file;
+ Dwarf_Die *cu_die;
+ Dwarf_Die *sp_die;
+ int found;
+};
+
+static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
+{
+ struct pubname_callback_param *param = data;
+
+ if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
+ if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
+ return DWARF_CB_OK;
+
+ if (die_compare_name(param->sp_die, param->function)) {
+ if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
+ return DWARF_CB_OK;
+
+ if (param->file &&
+ strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
+ return DWARF_CB_OK;
+
+ param->found = 1;
+ return DWARF_CB_ABORT;
+ }
+ }
+
+ return DWARF_CB_OK;
+}
+
+/* Find probe points from debuginfo */
+static int find_probes(int fd, struct probe_finder *pf)
+{
+ struct perf_probe_point *pp = &pf->pev->point;
+ Dwarf_Off off, noff;
+ size_t cuhl;
+ Dwarf_Die *diep;
+ Dwarf *dbg = NULL;
+ Dwfl *dwfl;
+ Dwarf_Addr bias; /* Currently ignored */
+ int ret = 0;
+
+ dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
+ if (!dbg) {
+ pr_warning("No debug information found in the vmlinux - "
+ "please rebuild with CONFIG_DEBUG_INFO=y.\n");
+ close(fd); /* Without dwfl_end(), fd isn't closed. */
+ return -EBADF;
+ }
+
+#if _ELFUTILS_PREREQ(0, 142)
+ /* Get the call frame information from this dwarf */
+ pf->cfi = dwarf_getcfi(dbg);
+#endif
+
+ off = 0;
+ line_list__init(&pf->lcache);
+
+ /* Fastpath: lookup by function name from .debug_pubnames section */
+ if (pp->function) {
+ struct pubname_callback_param pubname_param = {
+ .function = pp->function,
+ .file = pp->file,
+ .cu_die = &pf->cu_die,
+ .sp_die = &pf->sp_die,
+ .found = 0,
+ };
+ struct dwarf_callback_param probe_param = {
+ .data = pf,
+ };
+
+ dwarf_getpubnames(dbg, pubname_search_cb, &pubname_param, 0);
+ if (pubname_param.found) {
+ ret = probe_point_search_cb(&pf->sp_die, &probe_param);
+ if (ret)
+ goto found;
+ }
+ }
+
+ /* Loop on CUs (Compilation Unit) */
+ while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
+ /* Get the DIE(Debugging Information Entry) of this CU */
+ diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die);
+ if (!diep)
+ continue;
+
+ /* Check if target file is included. */
+ if (pp->file)
+ pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
+ else
+ pf->fname = NULL;
+
+ if (!pp->file || pf->fname) {
+ if (pp->function)
+ ret = find_probe_point_by_func(pf);
+ else if (pp->lazy_line)
+ ret = find_probe_point_lazy(NULL, pf);
+ else {
+ pf->lno = pp->line;
+ ret = find_probe_point_by_line(pf);
+ }
+ if (ret < 0)
+ break;
+ }
+ off = noff;
+ }
+
+found:
+ line_list__free(&pf->lcache);
+ if (dwfl)
+ dwfl_end(dwfl);
+
+ return ret;
+}
+
+/* Add a found probe point into trace event list */
+static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
+{
+ struct trace_event_finder *tf =
+ container_of(pf, struct trace_event_finder, pf);
+ struct probe_trace_event *tev;
+ int ret, i;
+
+ /* Check number of tevs */
+ if (tf->ntevs == tf->max_tevs) {
+ pr_warning("Too many( > %d) probe point found.\n",
+ tf->max_tevs);
+ return -ERANGE;
+ }
+ tev = &tf->tevs[tf->ntevs++];
+
+ ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
+ &tev->point);
+ if (ret < 0)
+ return ret;
+
+ pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
+ tev->point.offset);
+
+ /* Find each argument */
+ tev->nargs = pf->pev->nargs;
+ tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
+ if (tev->args == NULL)
+ return -ENOMEM;
+ for (i = 0; i < pf->pev->nargs; i++) {
+ pf->pvar = &pf->pev->args[i];
+ pf->tvar = &tev->args[i];
+ ret = find_variable(sp_die, pf);
+ if (ret != 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+/* Find probe_trace_events specified by perf_probe_event from debuginfo */
+int find_probe_trace_events(int fd, struct perf_probe_event *pev,
+ struct probe_trace_event **tevs, int max_tevs)
+{
+ struct trace_event_finder tf = {
+ .pf = {.pev = pev, .callback = add_probe_trace_event},
+ .max_tevs = max_tevs};
+ int ret;
+
+ /* Allocate result tevs array */
+ *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
+ if (*tevs == NULL)
+ return -ENOMEM;
+
+ tf.tevs = *tevs;
+ tf.ntevs = 0;
+
+ ret = find_probes(fd, &tf.pf);
+ if (ret < 0) {
+ free(*tevs);
+ *tevs = NULL;
+ return ret;
+ }
+
+ return (ret < 0) ? ret : tf.ntevs;
+}
+
+#define MAX_VAR_LEN 64
+
+/* Collect available variables in this scope */
+static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
+{
+ struct available_var_finder *af = data;
+ struct variable_list *vl;
+ char buf[MAX_VAR_LEN];
+ int tag, ret;
+
+ vl = &af->vls[af->nvls - 1];
+
+ tag = dwarf_tag(die_mem);
+ if (tag == DW_TAG_formal_parameter ||
+ tag == DW_TAG_variable) {
+ ret = convert_variable_location(die_mem, af->pf.addr,
+ af->pf.fb_ops, NULL);
+ if (ret == 0) {
+ ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
+ pr_debug2("Add new var: %s\n", buf);
+ if (ret > 0)
+ strlist__add(vl->vars, buf);
+ }
+ }
+
+ if (af->child && dwarf_haspc(die_mem, af->pf.addr))
+ return DIE_FIND_CB_CONTINUE;
+ else
+ return DIE_FIND_CB_SIBLING;
+}
+
+/* Add a found vars into available variables list */
+static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
+{
+ struct available_var_finder *af =
+ container_of(pf, struct available_var_finder, pf);
+ struct variable_list *vl;
+ Dwarf_Die die_mem, *scopes = NULL;
+ int ret, nscopes;
+
+ /* Check number of tevs */
+ if (af->nvls == af->max_vls) {
+ pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
+ return -ERANGE;
+ }
+ vl = &af->vls[af->nvls++];
+
+ ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
+ &vl->point);
+ if (ret < 0)
+ return ret;
+
+ pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
+ vl->point.offset);
+
+ /* Find local variables */
+ vl->vars = strlist__new(true, NULL);
+ if (vl->vars == NULL)
+ return -ENOMEM;
+ af->child = true;
+ die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
+
+ /* Find external variables */
+ if (!af->externs)
+ goto out;
+ /* Don't need to search child DIE for externs. */
+ af->child = false;
+ nscopes = dwarf_getscopes_die(sp_die, &scopes);
+ while (nscopes-- > 1)
+ die_find_child(&scopes[nscopes], collect_variables_cb,
+ (void *)af, &die_mem);
+ if (scopes)
+ free(scopes);
+
+out:
+ if (strlist__empty(vl->vars)) {
+ strlist__delete(vl->vars);
+ vl->vars = NULL;
+ }
+
+ return ret;
+}
+
+/* Find available variables at given probe point */
+int find_available_vars_at(int fd, struct perf_probe_event *pev,
+ struct variable_list **vls, int max_vls,
+ bool externs)
+{
+ struct available_var_finder af = {
+ .pf = {.pev = pev, .callback = add_available_vars},
+ .max_vls = max_vls, .externs = externs};
+ int ret;
+
+ /* Allocate result vls array */
+ *vls = zalloc(sizeof(struct variable_list) * max_vls);
+ if (*vls == NULL)
+ return -ENOMEM;
+
+ af.vls = *vls;
+ af.nvls = 0;
+
+ ret = find_probes(fd, &af.pf);
+ if (ret < 0) {
+ /* Free vlist for error */
+ while (af.nvls--) {
+ if (af.vls[af.nvls].point.symbol)
+ free(af.vls[af.nvls].point.symbol);
+ if (af.vls[af.nvls].vars)
+ strlist__delete(af.vls[af.nvls].vars);
+ }
+ free(af.vls);
+ *vls = NULL;
+ return ret;
+ }
+
+ return (ret < 0) ? ret : af.nvls;
+}
+
+/* Reverse search */
+int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
+{
+ Dwarf_Die cudie, spdie, indie;
+ Dwarf *dbg = NULL;
+ Dwfl *dwfl = NULL;
+ Dwarf_Addr _addr, baseaddr, bias = 0;
+ const char *fname = NULL, *func = NULL, *tmp;
+ int baseline = 0, lineno = 0, ret = 0;
+
+ /* Open the live linux kernel */
+ dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
+ if (!dbg) {
+ pr_warning("No debug information found in the vmlinux - "
+ "please rebuild with CONFIG_DEBUG_INFO=y.\n");
+ ret = -EINVAL;
+ goto end;
+ }
+
+ /* Adjust address with bias */
+ addr += bias;
+ /* Find cu die */
+ if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
+ pr_warning("Failed to find debug information for address %lx\n",
+ addr);
+ ret = -EINVAL;
+ goto end;
+ }
+
+ /* Find a corresponding line (filename and lineno) */
+ cu_find_lineinfo(&cudie, addr, &fname, &lineno);
+ /* Don't care whether it failed or not */
+
+ /* Find a corresponding function (name, baseline and baseaddr) */
+ if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
+ /* Get function entry information */
+ tmp = dwarf_diename(&spdie);
+ if (!tmp ||
+ dwarf_entrypc(&spdie, &baseaddr) != 0 ||
+ dwarf_decl_line(&spdie, &baseline) != 0)
+ goto post;
+ func = tmp;
+
+ if (addr == (unsigned long)baseaddr)
+ /* Function entry - Relative line number is 0 */
+ lineno = baseline;
+ else if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
+ &indie)) {
+ if (dwarf_entrypc(&indie, &_addr) == 0 &&
+ _addr == addr)
+ /*
+ * addr is at an inline function entry.
+ * In this case, lineno should be the call-site
+ * line number.
+ */
+ lineno = die_get_call_lineno(&indie);
+ else {
+ /*
+ * addr is in an inline function body.
+ * Since lineno points one of the lines
+ * of the inline function, baseline should
+ * be the entry line of the inline function.
+ */
+ tmp = dwarf_diename(&indie);
+ if (tmp &&
+ dwarf_decl_line(&spdie, &baseline) == 0)
+ func = tmp;
+ }
+ }
+ }
+
+post:
+ /* Make a relative line number or an offset */
+ if (lineno)
+ ppt->line = lineno - baseline;
+ else if (func)
+ ppt->offset = addr - (unsigned long)baseaddr;
+
+ /* Duplicate strings */
+ if (func) {
+ ppt->function = strdup(func);
+ if (ppt->function == NULL) {
+ ret = -ENOMEM;
+ goto end;
+ }
+ }
+ if (fname) {
+ ppt->file = strdup(fname);
+ if (ppt->file == NULL) {
+ if (ppt->function) {
+ free(ppt->function);
+ ppt->function = NULL;
+ }
+ ret = -ENOMEM;
+ goto end;
+ }
+ }
+end:
+ if (dwfl)
+ dwfl_end(dwfl);
+ if (ret == 0 && (fname || func))
+ ret = 1; /* Found a point */
+ return ret;
+}
+
+/* Add a line and store the src path */
+static int line_range_add_line(const char *src, unsigned int lineno,
+ struct line_range *lr)
+{
+ /* Copy source path */
+ if (!lr->path) {
+ lr->path = strdup(src);
+ if (lr->path == NULL)
+ return -ENOMEM;
+ }
+ return line_list__add_line(&lr->line_list, lineno);
+}
+
+static int line_range_walk_cb(const char *fname, int lineno,
+ Dwarf_Addr addr __used,
+ void *data)
+{
+ struct line_finder *lf = data;
+
+ if ((strtailcmp(fname, lf->fname) != 0) ||
+ (lf->lno_s > lineno || lf->lno_e < lineno))
+ return 0;
+
+ if (line_range_add_line(fname, lineno, lf->lr) < 0)
+ return -EINVAL;
+
+ return 0;
+}
+
+/* Find line range from its line number */
+static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
+{
+ int ret;
+
+ ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
+
+ /* Update status */
+ if (ret >= 0)
+ if (!list_empty(&lf->lr->line_list))
+ ret = lf->found = 1;
+ else
+ ret = 0; /* Lines are not found */
+ else {
+ free(lf->lr->path);
+ lf->lr->path = NULL;
+ }
+ return ret;
+}
+
+static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
+{
+ struct dwarf_callback_param *param = data;
+
+ param->retval = find_line_range_by_line(in_die, param->data);
+ return DWARF_CB_ABORT; /* No need to find other instances */
+}
+
+/* Search function from function name */
+static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
+{
+ struct dwarf_callback_param *param = data;
+ struct line_finder *lf = param->data;
+ struct line_range *lr = lf->lr;
+
+ /* Check declared file */
+ if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
+ return DWARF_CB_OK;
+
+ if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
+ die_compare_name(sp_die, lr->function)) {
+ lf->fname = dwarf_decl_file(sp_die);
+ dwarf_decl_line(sp_die, &lr->offset);
+ pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
+ lf->lno_s = lr->offset + lr->start;
+ if (lf->lno_s < 0) /* Overflow */
+ lf->lno_s = INT_MAX;
+ lf->lno_e = lr->offset + lr->end;
+ if (lf->lno_e < 0) /* Overflow */
+ lf->lno_e = INT_MAX;
+ pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
+ lr->start = lf->lno_s;
+ lr->end = lf->lno_e;
+ if (dwarf_func_inline(sp_die)) {
+ struct dwarf_callback_param _param;
+ _param.data = (void *)lf;
+ _param.retval = 0;
+ dwarf_func_inline_instances(sp_die,
+ line_range_inline_cb,
+ &_param);
+ param->retval = _param.retval;
+ } else
+ param->retval = find_line_range_by_line(sp_die, lf);
+ return DWARF_CB_ABORT;
+ }
+ return DWARF_CB_OK;
+}
+
+static int find_line_range_by_func(struct line_finder *lf)
+{
+ struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
+ dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
+ return param.retval;
+}
+
+int find_line_range(int fd, struct line_range *lr)
+{
+ struct line_finder lf = {.lr = lr, .found = 0};
+ int ret = 0;
+ Dwarf_Off off = 0, noff;
+ size_t cuhl;
+ Dwarf_Die *diep;
+ Dwarf *dbg = NULL;
+ Dwfl *dwfl;
+ Dwarf_Addr bias; /* Currently ignored */
+ const char *comp_dir;
+
+ dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
+ if (!dbg) {
+ pr_warning("No debug information found in the vmlinux - "
+ "please rebuild with CONFIG_DEBUG_INFO=y.\n");
+ close(fd); /* Without dwfl_end(), fd isn't closed. */
+ return -EBADF;
+ }
+
+ /* Fastpath: lookup by function name from .debug_pubnames section */
+ if (lr->function) {
+ struct pubname_callback_param pubname_param = {
+ .function = lr->function, .file = lr->file,
+ .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
+ struct dwarf_callback_param line_range_param = {
+ .data = (void *)&lf, .retval = 0};
+
+ dwarf_getpubnames(dbg, pubname_search_cb, &pubname_param, 0);
+ if (pubname_param.found) {
+ line_range_search_cb(&lf.sp_die, &line_range_param);
+ if (lf.found)
+ goto found;
+ }
+ }
+
+ /* Loop on CUs (Compilation Unit) */
+ while (!lf.found && ret >= 0) {
+ if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
+ break;
+
+ /* Get the DIE(Debugging Information Entry) of this CU */
+ diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
+ if (!diep)
+ continue;
+
+ /* Check if target file is included. */
+ if (lr->file)
+ lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
+ else
+ lf.fname = 0;
+
+ if (!lr->file || lf.fname) {
+ if (lr->function)
+ ret = find_line_range_by_func(&lf);
+ else {
+ lf.lno_s = lr->start;
+ lf.lno_e = lr->end;
+ ret = find_line_range_by_line(NULL, &lf);
+ }
+ }
+ off = noff;
+ }
+
+found:
+ /* Store comp_dir */
+ if (lf.found) {
+ comp_dir = cu_get_comp_dir(&lf.cu_die);
+ if (comp_dir) {
+ lr->comp_dir = strdup(comp_dir);
+ if (!lr->comp_dir)
+ ret = -ENOMEM;
+ }
+ }
+
+ pr_debug("path: %s\n", lr->path);
+ dwfl_end(dwfl);
+ return (ret < 0) ? ret : lf.found;
+}
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-10 13:05:50 +0000