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-rw-r--r--tools/perf/util/probe-finder.c732
1 files changed, 732 insertions, 0 deletions
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
new file mode 100644
index 000000000000..293cdfc1b8ca
--- /dev/null
+++ b/tools/perf/util/probe-finder.c
@@ -0,0 +1,732 @@
+/*
+ * 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 "event.h"
+#include "debug.h"
+#include "util.h"
+#include "probe-finder.h"
+
+
+/* Dwarf_Die Linkage to parent Die */
+struct die_link {
+ struct die_link *parent; /* Parent die */
+ Dwarf_Die die; /* Current die */
+};
+
+static Dwarf_Debug __dw_debug;
+static Dwarf_Error __dw_error;
+
+/*
+ * Generic dwarf analysis helpers
+ */
+
+#define X86_32_MAX_REGS 8
+const char *x86_32_regs_table[X86_32_MAX_REGS] = {
+ "%ax",
+ "%cx",
+ "%dx",
+ "%bx",
+ "$stack", /* Stack address instead of %sp */
+ "%bp",
+ "%si",
+ "%di",
+};
+
+#define X86_64_MAX_REGS 16
+const char *x86_64_regs_table[X86_64_MAX_REGS] = {
+ "%ax",
+ "%dx",
+ "%cx",
+ "%bx",
+ "%si",
+ "%di",
+ "%bp",
+ "%sp",
+ "%r8",
+ "%r9",
+ "%r10",
+ "%r11",
+ "%r12",
+ "%r13",
+ "%r14",
+ "%r15",
+};
+
+/* TODO: switching by dwarf address size */
+#ifdef __x86_64__
+#define ARCH_MAX_REGS X86_64_MAX_REGS
+#define arch_regs_table x86_64_regs_table
+#else
+#define ARCH_MAX_REGS X86_32_MAX_REGS
+#define arch_regs_table x86_32_regs_table
+#endif
+
+/* Return architecture dependent register string (for kprobe-tracer) */
+static const char *get_arch_regstr(unsigned int n)
+{
+ return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
+}
+
+/*
+ * 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;
+}
+
+/* Find the fileno of the target file. */
+static Dwarf_Unsigned cu_find_fileno(Dwarf_Die cu_die, const char *fname)
+{
+ Dwarf_Signed cnt, i;
+ Dwarf_Unsigned found = 0;
+ char **srcs;
+ int ret;
+
+ if (!fname)
+ return 0;
+
+ ret = dwarf_srcfiles(cu_die, &srcs, &cnt, &__dw_error);
+ if (ret == DW_DLV_OK) {
+ for (i = 0; i < cnt && !found; i++) {
+ if (strtailcmp(srcs[i], fname) == 0)
+ found = i + 1;
+ dwarf_dealloc(__dw_debug, srcs[i], DW_DLA_STRING);
+ }
+ for (; i < cnt; i++)
+ dwarf_dealloc(__dw_debug, srcs[i], DW_DLA_STRING);
+ dwarf_dealloc(__dw_debug, srcs, DW_DLA_LIST);
+ }
+ if (found)
+ pr_debug("found fno: %d\n", (int)found);
+ return found;
+}
+
+/* Compare diename and tname */
+static int die_compare_name(Dwarf_Die dw_die, const char *tname)
+{
+ char *name;
+ int ret;
+ ret = dwarf_diename(dw_die, &name, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ if (ret == DW_DLV_OK) {
+ ret = strcmp(tname, name);
+ dwarf_dealloc(__dw_debug, name, DW_DLA_STRING);
+ } else
+ ret = -1;
+ return ret;
+}
+
+/* Check the address is in the subprogram(function). */
+static int die_within_subprogram(Dwarf_Die sp_die, Dwarf_Addr addr,
+ Dwarf_Signed *offs)
+{
+ Dwarf_Addr lopc, hipc;
+ int ret;
+
+ /* TODO: check ranges */
+ ret = dwarf_lowpc(sp_die, &lopc, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ if (ret == DW_DLV_NO_ENTRY)
+ return 0;
+ ret = dwarf_highpc(sp_die, &hipc, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ if (lopc <= addr && addr < hipc) {
+ *offs = addr - lopc;
+ return 1;
+ } else
+ return 0;
+}
+
+/* Check the die is inlined function */
+static Dwarf_Bool die_inlined_subprogram(Dwarf_Die dw_die)
+{
+ /* TODO: check strictly */
+ Dwarf_Bool inl;
+ int ret;
+
+ ret = dwarf_hasattr(dw_die, DW_AT_inline, &inl, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ return inl;
+}
+
+/* Get the offset of abstruct_origin */
+static Dwarf_Off die_get_abstract_origin(Dwarf_Die dw_die)
+{
+ Dwarf_Attribute attr;
+ Dwarf_Off cu_offs;
+ int ret;
+
+ ret = dwarf_attr(dw_die, DW_AT_abstract_origin, &attr, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ ret = dwarf_formref(attr, &cu_offs, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR);
+ return cu_offs;
+}
+
+/* Get entry pc(or low pc, 1st entry of ranges) of the die */
+static Dwarf_Addr die_get_entrypc(Dwarf_Die dw_die)
+{
+ Dwarf_Attribute attr;
+ Dwarf_Addr addr;
+ Dwarf_Off offs;
+ Dwarf_Ranges *ranges;
+ Dwarf_Signed cnt;
+ int ret;
+
+ /* Try to get entry pc */
+ ret = dwarf_attr(dw_die, DW_AT_entry_pc, &attr, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ if (ret == DW_DLV_OK) {
+ ret = dwarf_formaddr(attr, &addr, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR);
+ return addr;
+ }
+
+ /* Try to get low pc */
+ ret = dwarf_lowpc(dw_die, &addr, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ if (ret == DW_DLV_OK)
+ return addr;
+
+ /* Try to get ranges */
+ ret = dwarf_attr(dw_die, DW_AT_ranges, &attr, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ ret = dwarf_formref(attr, &offs, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ ret = dwarf_get_ranges(__dw_debug, offs, &ranges, &cnt, NULL,
+ &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ addr = ranges[0].dwr_addr1;
+ dwarf_ranges_dealloc(__dw_debug, ranges, cnt);
+ return addr;
+}
+
+/*
+ * Search a Die from Die tree.
+ * Note: cur_link->die should be deallocated in this function.
+ */
+static int __search_die_tree(struct die_link *cur_link,
+ int (*die_cb)(struct die_link *, void *),
+ void *data)
+{
+ Dwarf_Die new_die;
+ struct die_link new_link;
+ int ret;
+
+ if (!die_cb)
+ return 0;
+
+ /* Check current die */
+ while (!(ret = die_cb(cur_link, data))) {
+ /* Check child die */
+ ret = dwarf_child(cur_link->die, &new_die, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ if (ret == DW_DLV_OK) {
+ new_link.parent = cur_link;
+ new_link.die = new_die;
+ ret = __search_die_tree(&new_link, die_cb, data);
+ if (ret)
+ break;
+ }
+
+ /* Move to next sibling */
+ ret = dwarf_siblingof(__dw_debug, cur_link->die, &new_die,
+ &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ dwarf_dealloc(__dw_debug, cur_link->die, DW_DLA_DIE);
+ cur_link->die = new_die;
+ if (ret == DW_DLV_NO_ENTRY)
+ return 0;
+ }
+ dwarf_dealloc(__dw_debug, cur_link->die, DW_DLA_DIE);
+ return ret;
+}
+
+/* Search a die in its children's die tree */
+static int search_die_from_children(Dwarf_Die parent_die,
+ int (*die_cb)(struct die_link *, void *),
+ void *data)
+{
+ struct die_link new_link;
+ int ret;
+
+ new_link.parent = NULL;
+ ret = dwarf_child(parent_die, &new_link.die, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ if (ret == DW_DLV_OK)
+ return __search_die_tree(&new_link, die_cb, data);
+ else
+ return 0;
+}
+
+/* Find a locdesc corresponding to the address */
+static int attr_get_locdesc(Dwarf_Attribute attr, Dwarf_Locdesc *desc,
+ Dwarf_Addr addr)
+{
+ Dwarf_Signed lcnt;
+ Dwarf_Locdesc **llbuf;
+ int ret, i;
+
+ ret = dwarf_loclist_n(attr, &llbuf, &lcnt, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ ret = DW_DLV_NO_ENTRY;
+ for (i = 0; i < lcnt; ++i) {
+ if (llbuf[i]->ld_lopc <= addr &&
+ llbuf[i]->ld_hipc > addr) {
+ memcpy(desc, llbuf[i], sizeof(Dwarf_Locdesc));
+ desc->ld_s =
+ malloc(sizeof(Dwarf_Loc) * llbuf[i]->ld_cents);
+ DIE_IF(desc->ld_s == NULL);
+ memcpy(desc->ld_s, llbuf[i]->ld_s,
+ sizeof(Dwarf_Loc) * llbuf[i]->ld_cents);
+ ret = DW_DLV_OK;
+ break;
+ }
+ dwarf_dealloc(__dw_debug, llbuf[i]->ld_s, DW_DLA_LOC_BLOCK);
+ dwarf_dealloc(__dw_debug, llbuf[i], DW_DLA_LOCDESC);
+ }
+ /* Releasing loop */
+ for (; i < lcnt; ++i) {
+ dwarf_dealloc(__dw_debug, llbuf[i]->ld_s, DW_DLA_LOC_BLOCK);
+ dwarf_dealloc(__dw_debug, llbuf[i], DW_DLA_LOCDESC);
+ }
+ dwarf_dealloc(__dw_debug, llbuf, DW_DLA_LIST);
+ return ret;
+}
+
+/* Get decl_file attribute value (file number) */
+static Dwarf_Unsigned die_get_decl_file(Dwarf_Die sp_die)
+{
+ Dwarf_Attribute attr;
+ Dwarf_Unsigned fno;
+ int ret;
+
+ ret = dwarf_attr(sp_die, DW_AT_decl_file, &attr, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ dwarf_formudata(attr, &fno, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR);
+ return fno;
+}
+
+/* Get decl_line attribute value (line number) */
+static Dwarf_Unsigned die_get_decl_line(Dwarf_Die sp_die)
+{
+ Dwarf_Attribute attr;
+ Dwarf_Unsigned lno;
+ int ret;
+
+ ret = dwarf_attr(sp_die, DW_AT_decl_line, &attr, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ dwarf_formudata(attr, &lno, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR);
+ return lno;
+}
+
+/*
+ * Probe finder related functions
+ */
+
+/* Show a location */
+static void show_location(Dwarf_Loc *loc, struct probe_finder *pf)
+{
+ Dwarf_Small op;
+ Dwarf_Unsigned regn;
+ Dwarf_Signed offs;
+ int deref = 0, ret;
+ const char *regs;
+
+ op = loc->lr_atom;
+
+ /* If this is based on frame buffer, set the offset */
+ if (op == DW_OP_fbreg) {
+ deref = 1;
+ offs = (Dwarf_Signed)loc->lr_number;
+ op = pf->fbloc.ld_s[0].lr_atom;
+ loc = &pf->fbloc.ld_s[0];
+ } else
+ offs = 0;
+
+ if (op >= DW_OP_breg0 && op <= DW_OP_breg31) {
+ regn = op - DW_OP_breg0;
+ offs += (Dwarf_Signed)loc->lr_number;
+ deref = 1;
+ } else if (op >= DW_OP_reg0 && op <= DW_OP_reg31) {
+ regn = op - DW_OP_reg0;
+ } else if (op == DW_OP_bregx) {
+ regn = loc->lr_number;
+ offs += (Dwarf_Signed)loc->lr_number2;
+ deref = 1;
+ } else if (op == DW_OP_regx) {
+ regn = loc->lr_number;
+ } else
+ die("Dwarf_OP %d is not supported.\n", op);
+
+ regs = get_arch_regstr(regn);
+ if (!regs)
+ die("%lld exceeds max register number.\n", regn);
+
+ if (deref)
+ ret = snprintf(pf->buf, pf->len,
+ " %s=%+lld(%s)", pf->var, offs, regs);
+ else
+ ret = snprintf(pf->buf, pf->len, " %s=%s", pf->var, regs);
+ DIE_IF(ret < 0);
+ DIE_IF(ret >= pf->len);
+}
+
+/* Show a variables in kprobe event format */
+static void show_variable(Dwarf_Die vr_die, struct probe_finder *pf)
+{
+ Dwarf_Attribute attr;
+ Dwarf_Locdesc ld;
+ int ret;
+
+ ret = dwarf_attr(vr_die, DW_AT_location, &attr, &__dw_error);
+ if (ret != DW_DLV_OK)
+ goto error;
+ ret = attr_get_locdesc(attr, &ld, (pf->addr - pf->cu_base));
+ if (ret != DW_DLV_OK)
+ goto error;
+ /* TODO? */
+ DIE_IF(ld.ld_cents != 1);
+ show_location(&ld.ld_s[0], pf);
+ free(ld.ld_s);
+ dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR);
+ return ;
+error:
+ die("Failed to find the location of %s at this address.\n"
+ " Perhaps, it has been optimized out.\n", pf->var);
+}
+
+static int variable_callback(struct die_link *dlink, void *data)
+{
+ struct probe_finder *pf = (struct probe_finder *)data;
+ Dwarf_Half tag;
+ int ret;
+
+ ret = dwarf_tag(dlink->die, &tag, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ if ((tag == DW_TAG_formal_parameter ||
+ tag == DW_TAG_variable) &&
+ (die_compare_name(dlink->die, pf->var) == 0)) {
+ show_variable(dlink->die, pf);
+ return 1;
+ }
+ /* TODO: Support struct members and arrays */
+ return 0;
+}
+
+/* Find a variable in a subprogram die */
+static void find_variable(Dwarf_Die sp_die, struct probe_finder *pf)
+{
+ int ret;
+
+ if (!is_c_varname(pf->var)) {
+ /* Output raw parameters */
+ ret = snprintf(pf->buf, pf->len, " %s", pf->var);
+ DIE_IF(ret < 0);
+ DIE_IF(ret >= pf->len);
+ return ;
+ }
+
+ pr_debug("Searching '%s' variable in context.\n", pf->var);
+ /* Search child die for local variables and parameters. */
+ ret = search_die_from_children(sp_die, variable_callback, pf);
+ if (!ret)
+ die("Failed to find '%s' in this function.\n", pf->var);
+}
+
+/* Get a frame base on the address */
+static void get_current_frame_base(Dwarf_Die sp_die, struct probe_finder *pf)
+{
+ Dwarf_Attribute attr;
+ int ret;
+
+ ret = dwarf_attr(sp_die, DW_AT_frame_base, &attr, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ ret = attr_get_locdesc(attr, &pf->fbloc, (pf->addr - pf->cu_base));
+ DIE_IF(ret != DW_DLV_OK);
+ dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR);
+}
+
+static void free_current_frame_base(struct probe_finder *pf)
+{
+ free(pf->fbloc.ld_s);
+ memset(&pf->fbloc, 0, sizeof(Dwarf_Locdesc));
+}
+
+/* Show a probe point to output buffer */
+static void show_probepoint(Dwarf_Die sp_die, Dwarf_Signed offs,
+ struct probe_finder *pf)
+{
+ struct probe_point *pp = pf->pp;
+ char *name;
+ char tmp[MAX_PROBE_BUFFER];
+ int ret, i, len;
+
+ /* Output name of probe point */
+ ret = dwarf_diename(sp_die, &name, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ if (ret == DW_DLV_OK) {
+ ret = snprintf(tmp, MAX_PROBE_BUFFER, "%s+%u", name,
+ (unsigned int)offs);
+ /* Copy the function name if possible */
+ if (!pp->function) {
+ pp->function = strdup(name);
+ pp->offset = offs;
+ }
+ dwarf_dealloc(__dw_debug, name, DW_DLA_STRING);
+ } else {
+ /* This function has no name. */
+ ret = snprintf(tmp, MAX_PROBE_BUFFER, "0x%llx", pf->addr);
+ if (!pp->function) {
+ /* TODO: Use _stext */
+ pp->function = strdup("");
+ pp->offset = (int)pf->addr;
+ }
+ }
+ DIE_IF(ret < 0);
+ DIE_IF(ret >= MAX_PROBE_BUFFER);
+ len = ret;
+ pr_debug("Probe point found: %s\n", tmp);
+
+ /* Find each argument */
+ get_current_frame_base(sp_die, pf);
+ for (i = 0; i < pp->nr_args; i++) {
+ pf->var = pp->args[i];
+ pf->buf = &tmp[len];
+ pf->len = MAX_PROBE_BUFFER - len;
+ find_variable(sp_die, pf);
+ len += strlen(pf->buf);
+ }
+ free_current_frame_base(pf);
+
+ pp->probes[pp->found] = strdup(tmp);
+ pp->found++;
+}
+
+static int probeaddr_callback(struct die_link *dlink, void *data)
+{
+ struct probe_finder *pf = (struct probe_finder *)data;
+ Dwarf_Half tag;
+ Dwarf_Signed offs;
+ int ret;
+
+ ret = dwarf_tag(dlink->die, &tag, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ /* Check the address is in this subprogram */
+ if (tag == DW_TAG_subprogram &&
+ die_within_subprogram(dlink->die, pf->addr, &offs)) {
+ show_probepoint(dlink->die, offs, pf);
+ return 1;
+ }
+ return 0;
+}
+
+/* Find probe point from its line number */
+static void find_by_line(struct probe_finder *pf)
+{
+ Dwarf_Signed cnt, i, clm;
+ Dwarf_Line *lines;
+ Dwarf_Unsigned lineno = 0;
+ Dwarf_Addr addr;
+ Dwarf_Unsigned fno;
+ int ret;
+
+ ret = dwarf_srclines(pf->cu_die, &lines, &cnt, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+
+ for (i = 0; i < cnt; i++) {
+ ret = dwarf_line_srcfileno(lines[i], &fno, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ if (fno != pf->fno)
+ continue;
+
+ ret = dwarf_lineno(lines[i], &lineno, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ if (lineno != pf->lno)
+ continue;
+
+ ret = dwarf_lineoff(lines[i], &clm, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+
+ ret = dwarf_lineaddr(lines[i], &addr, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ pr_debug("Probe line found: line[%d]:%u,%d addr:0x%llx\n",
+ (int)i, (unsigned)lineno, (int)clm, addr);
+ pf->addr = addr;
+ /* Search a real subprogram including this line, */
+ ret = search_die_from_children(pf->cu_die,
+ probeaddr_callback, pf);
+ if (ret == 0)
+ die("Probe point is not found in subprograms.\n");
+ /* Continuing, because target line might be inlined. */
+ }
+ dwarf_srclines_dealloc(__dw_debug, lines, cnt);
+}
+
+/* Search function from function name */
+static int probefunc_callback(struct die_link *dlink, void *data)
+{
+ struct probe_finder *pf = (struct probe_finder *)data;
+ struct probe_point *pp = pf->pp;
+ struct die_link *lk;
+ Dwarf_Signed offs;
+ Dwarf_Half tag;
+ int ret;
+
+ ret = dwarf_tag(dlink->die, &tag, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ if (tag == DW_TAG_subprogram) {
+ if (die_compare_name(dlink->die, pp->function) == 0) {
+ if (pp->line) { /* Function relative line */
+ pf->fno = die_get_decl_file(dlink->die);
+ pf->lno = die_get_decl_line(dlink->die)
+ + pp->line;
+ find_by_line(pf);
+ return 1;
+ }
+ if (die_inlined_subprogram(dlink->die)) {
+ /* Inlined function, save it. */
+ ret = dwarf_die_CU_offset(dlink->die,
+ &pf->inl_offs,
+ &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+ pr_debug("inline definition offset %lld\n",
+ pf->inl_offs);
+ return 0; /* Continue to search */
+ }
+ /* Get probe address */
+ pf->addr = die_get_entrypc(dlink->die);
+ pf->addr += pp->offset;
+ /* TODO: Check the address in this function */
+ show_probepoint(dlink->die, pp->offset, pf);
+ return 1; /* Exit; no same symbol in this CU. */
+ }
+ } else if (tag == DW_TAG_inlined_subroutine && pf->inl_offs) {
+ if (die_get_abstract_origin(dlink->die) == pf->inl_offs) {
+ /* Get probe address */
+ pf->addr = die_get_entrypc(dlink->die);
+ pf->addr += pp->offset;
+ pr_debug("found inline addr: 0x%llx\n", pf->addr);
+ /* Inlined function. Get a real subprogram */
+ for (lk = dlink->parent; lk != NULL; lk = lk->parent) {
+ tag = 0;
+ dwarf_tag(lk->die, &tag, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ if (tag == DW_TAG_subprogram &&
+ !die_inlined_subprogram(lk->die))
+ goto found;
+ }
+ die("Failed to find real subprogram.\n");
+found:
+ /* Get offset from subprogram */
+ ret = die_within_subprogram(lk->die, pf->addr, &offs);
+ DIE_IF(!ret);
+ show_probepoint(lk->die, offs, pf);
+ /* Continue to search */
+ }
+ }
+ return 0;
+}
+
+static void find_by_func(struct probe_finder *pf)
+{
+ search_die_from_children(pf->cu_die, probefunc_callback, pf);
+}
+
+/* Find a probe point */
+int find_probepoint(int fd, struct probe_point *pp)
+{
+ Dwarf_Half addr_size = 0;
+ Dwarf_Unsigned next_cuh = 0;
+ int cu_number = 0, ret;
+ struct probe_finder pf = {.pp = pp};
+
+ ret = dwarf_init(fd, DW_DLC_READ, 0, 0, &__dw_debug, &__dw_error);
+ if (ret != DW_DLV_OK) {
+ pr_warning("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO.\n");
+ return -ENOENT;
+ }
+
+ pp->found = 0;
+ while (++cu_number) {
+ /* Search CU (Compilation Unit) */
+ ret = dwarf_next_cu_header(__dw_debug, NULL, NULL, NULL,
+ &addr_size, &next_cuh, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ if (ret == DW_DLV_NO_ENTRY)
+ break;
+
+ /* Get the DIE(Debugging Information Entry) of this CU */
+ ret = dwarf_siblingof(__dw_debug, 0, &pf.cu_die, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+
+ /* Check if target file is included. */
+ if (pp->file)
+ pf.fno = cu_find_fileno(pf.cu_die, pp->file);
+
+ if (!pp->file || pf.fno) {
+ /* Save CU base address (for frame_base) */
+ ret = dwarf_lowpc(pf.cu_die, &pf.cu_base, &__dw_error);
+ DIE_IF(ret == DW_DLV_ERROR);
+ if (ret == DW_DLV_NO_ENTRY)
+ pf.cu_base = 0;
+ if (pp->function)
+ find_by_func(&pf);
+ else {
+ pf.lno = pp->line;
+ find_by_line(&pf);
+ }
+ }
+ dwarf_dealloc(__dw_debug, pf.cu_die, DW_DLA_DIE);
+ }
+ ret = dwarf_finish(__dw_debug, &__dw_error);
+ DIE_IF(ret != DW_DLV_OK);
+
+ return pp->found;
+}
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-28 16:00:13 +0000