linux/tools/perf/util/dwarf-aux.c
Masami Hiramatsu e08cfd4bda perf probe: Fix to find line information for probe list
Fix to find the correct (as much as possible) line information for
listing probes. Without this fix, perf probe --list action will show
incorrect line information as below;

  probe:getname_flags  (on getname_flags@ksrc/linux-3/fs/namei.c)
  probe:getname_flags_1 (on getname:-89@x86/include/asm/current.h)
  probe:getname_flags_2 (on user_path_at_empty:-2054@x86/include/asm/current.h)

The minus line number is obviously wrong, and current.h is not related
to the probe point. Deeper investigation discovered that there were 2
issues related to this bug, and minor typos too.

The 1st issue is the rack of considering about nested inlined functions,
which causes the wrong (relative) line number.

The 2nd issue is that the dwarf line info is not correct at those
points. It points 14th line of current.h.

Since it seems that the line info includes somewhat unreliable
information, this fixes perf to try to find correct line information
from both of debuginfo and line info as below.

1) Probe address is the entry of a function instance

  In this case, the line is set as the function declared line.

2) Probe address is the entry of an expanded inline function block

  In this case, the line is set as the function call-site line.
  This means that the line number is relative from the entry line
  of caller function (which can be an inlined function if nested)

3) Probe address is inside a function instance or an expanded
   inline function block

  In this case, perf probe queries the line number from lineinfo
  and verify the function declared file is same as the file name
  queried from lineinfo.

  If the file name is different, it is a failure case. The probe
  address is shown as symbol+offset.

4) Probe address is not in the any function instance

  This is a failure case, the probe address is shown as
  symbol+offset.

With this fix, perf probe -l shows correct probe lines as below;

  probe:getname_flags  (on getname_flags@ksrc/linux-3/fs/namei.c)
  probe:getname_flags_1 (on getname:2@ksrc/linux-3/fs/namei.c)
  probe:getname_flags_2 (on user_path_at_empty:4@ksrc/linux-3/fs/namei.c)

Changes at v2:
 - Fix typos in the function comments. (Thanks to Namhyung Kim)
 - Use die_find_top_inlinefunc instead of die_find_inlinefunc_next.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130930092144.1693.11058.stgit@udc4-manage.rcp.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-10-04 15:16:05 -03:00

882 lines
23 KiB
C

/*
* dwarf-aux.c : libdw auxiliary interfaces
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
#include <stdbool.h>
#include "util.h"
#include "debug.h"
#include "dwarf-aux.h"
/**
* cu_find_realpath - Find the realpath of the target file
* @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
* @fname: The tail filename of the target file
*
* Find the real(long) path of @fname in @cu_die.
*/
const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
{
Dwarf_Files *files;
size_t nfiles, i;
const char *src = NULL;
int ret;
if (!fname)
return NULL;
ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
if (ret != 0)
return NULL;
for (i = 0; i < nfiles; i++) {
src = dwarf_filesrc(files, i, NULL, NULL);
if (strtailcmp(src, fname) == 0)
break;
}
if (i == nfiles)
return NULL;
return src;
}
/**
* cu_get_comp_dir - Get the path of compilation directory
* @cu_die: a CU DIE
*
* Get the path of compilation directory of given @cu_die.
* Since this depends on DW_AT_comp_dir, older gcc will not
* embedded it. In that case, this returns NULL.
*/
const char *cu_get_comp_dir(Dwarf_Die *cu_die)
{
Dwarf_Attribute attr;
if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
return NULL;
return dwarf_formstring(&attr);
}
/**
* cu_find_lineinfo - Get a line number and file name for given address
* @cu_die: a CU DIE
* @addr: An address
* @fname: a pointer which returns the file name string
* @lineno: a pointer which returns the line number
*
* Find a line number and file name for @addr in @cu_die.
*/
int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
const char **fname, int *lineno)
{
Dwarf_Line *line;
Dwarf_Addr laddr;
line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr);
if (line && dwarf_lineaddr(line, &laddr) == 0 &&
addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
*fname = dwarf_linesrc(line, NULL, NULL);
if (!*fname)
/* line number is useless without filename */
*lineno = 0;
}
return *lineno ?: -ENOENT;
}
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_compare_name - Compare diename and tname
* @dw_die: a DIE
* @tname: a string of target name
*
* Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
*/
bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
{
const char *name;
name = dwarf_diename(dw_die);
return name ? (strcmp(tname, name) == 0) : false;
}
/**
* die_get_call_lineno - Get callsite line number of inline-function instance
* @in_die: a DIE of an inlined function instance
*
* Get call-site line number of @in_die. This means from where the inline
* function is called.
*/
int die_get_call_lineno(Dwarf_Die *in_die)
{
Dwarf_Attribute attr;
Dwarf_Word ret;
if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
return -ENOENT;
dwarf_formudata(&attr, &ret);
return (int)ret;
}
/**
* die_get_type - Get type DIE
* @vr_die: a DIE of a variable
* @die_mem: where to store a type DIE
*
* Get a DIE of the type of given variable (@vr_die), and store
* it to die_mem. Return NULL if fails to get a type DIE.
*/
Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
{
Dwarf_Attribute attr;
if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
dwarf_formref_die(&attr, die_mem))
return die_mem;
else
return NULL;
}
/* Get a type die, but skip qualifiers */
static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
{
int tag;
do {
vr_die = die_get_type(vr_die, die_mem);
if (!vr_die)
break;
tag = dwarf_tag(vr_die);
} while (tag == DW_TAG_const_type ||
tag == DW_TAG_restrict_type ||
tag == DW_TAG_volatile_type ||
tag == DW_TAG_shared_type);
return vr_die;
}
/**
* die_get_real_type - Get a type die, but skip qualifiers and typedef
* @vr_die: a DIE of a variable
* @die_mem: where to store a type DIE
*
* Get a DIE of the type of given variable (@vr_die), and store
* it to die_mem. Return NULL if fails to get a type DIE.
* If the type is qualifiers (e.g. const) or typedef, this skips it
* and tries to find real type (structure or basic types, e.g. int).
*/
Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
{
do {
vr_die = __die_get_real_type(vr_die, die_mem);
} while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
return vr_die;
}
/* Get attribute and translate it as a udata */
static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
Dwarf_Word *result)
{
Dwarf_Attribute attr;
if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
dwarf_formudata(&attr, result) != 0)
return -ENOENT;
return 0;
}
/* Get attribute and translate it as a sdata */
static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
Dwarf_Sword *result)
{
Dwarf_Attribute attr;
if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
dwarf_formsdata(&attr, result) != 0)
return -ENOENT;
return 0;
}
/**
* die_is_signed_type - Check whether a type DIE is signed or not
* @tp_die: a DIE of a type
*
* 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;
return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
dwarf_attr(dw_die, DW_AT_declaration, &attr) == 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_Sword idx;
if (die_get_attr_sdata(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_Sword idx;
if (die_get_attr_sdata(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;
};
/* 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;
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
* declartion. 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 && dwarf_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)
/* Don't need to search recursively */
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 &&
dwarf_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;
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;
int lineno, ret = 0;
Dwarf_Die die_mem, *cu_die;
size_t nlines, i;
/* Get the CU die */
if (dwarf_tag(rt_die) != DW_TAG_compile_unit)
cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
else
cu_die = rt_die;
if (!cu_die) {
pr_debug2("Failed to get CU from 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;
}
/* Filter lines based on address */
if (rt_die != cu_die)
/*
* Address filtering
* The line is included in given function, and
* no inline block includes it.
*/
if (!dwarf_haspc(rt_die, addr) ||
die_find_inlinefunc(rt_die, addr, &die_mem))
continue;
/* Get source line */
fname = dwarf_linesrc(line, NULL, NULL);
ret = callback(fname, lineno, addr, data);
if (ret != 0)
return ret;
}
/*
* Dwarf lines doesn't include function declarations and inlined
* subroutines. We have to check functions list or given function.
*/
if (rt_die != cu_die)
/*
* Don't need walk functions recursively, because nested
* inlined functions don't have lines of the specified DIE.
*/
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;
int tag;
tag = dwarf_tag(die_mem);
if ((tag == DW_TAG_formal_parameter ||
tag == DW_TAG_variable) &&
die_compare_name(die_mem, fvp->name))
return DIE_FIND_CB_END;
if (dwarf_haspc(die_mem, fvp->addr))
return DIE_FIND_CB_CONTINUE;
else
return DIE_FIND_CB_SIBLING;
}
/**
* die_find_variable_at - Find a given name variable at given address
* @sp_die: a function DIE
* @name: variable name
* @addr: address
* @die_mem: a buffer for result DIE
*
* Find a variable DIE called @name at @addr in @sp_die.
*/
Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
Dwarf_Addr addr, Dwarf_Die *die_mem)
{
struct __find_variable_param fvp = { .name = name, .addr = addr};
return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
die_mem);
}
static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
{
const char *name = data;
if ((dwarf_tag(die_mem) == DW_TAG_member) &&
die_compare_name(die_mem, name))
return DIE_FIND_CB_END;
return DIE_FIND_CB_SIBLING;
}
/**
* die_find_member - Find a given name member in a data structure
* @st_die: a data structure type DIE
* @name: member name
* @die_mem: a buffer for result DIE
*
* Find a member DIE called @name in @st_die.
*/
Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
Dwarf_Die *die_mem)
{
return die_find_child(st_die, __die_find_member_cb, (void *)name,
die_mem);
}
/**
* die_get_typename - Get the name of given variable DIE
* @vr_die: a variable DIE
* @buf: a buffer for result type name
* @len: a max-length of @buf
*
* Get the name of @vr_die and stores it to @buf. Return the actual length
* of type name if succeeded. Return -E2BIG if @len is not enough long, and
* Return -ENOENT if failed to find type name.
* Note that the result will stores typedef name if possible, and stores
* "*(function_type)" if the type is a function pointer.
*/
int die_get_typename(Dwarf_Die *vr_die, char *buf, int len)
{
Dwarf_Die type;
int tag, ret, ret2;
const char *tmp = "";
if (__die_get_real_type(vr_die, &type) == NULL)
return -ENOENT;
tag = dwarf_tag(&type);
if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
tmp = "*";
else if (tag == DW_TAG_subroutine_type) {
/* Function pointer */
ret = snprintf(buf, len, "(function_type)");
return (ret >= len) ? -E2BIG : ret;
} else {
if (!dwarf_diename(&type))
return -ENOENT;
if (tag == DW_TAG_union_type)
tmp = "union ";
else if (tag == DW_TAG_structure_type)
tmp = "struct ";
else if (tag == DW_TAG_enumeration_type)
tmp = "enum ";
/* Write a base name */
ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
return (ret >= len) ? -E2BIG : ret;
}
ret = die_get_typename(&type, buf, len);
if (ret > 0) {
ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
}
return ret;
}
/**
* die_get_varname - Get the name and type of given variable DIE
* @vr_die: a variable DIE
* @buf: a buffer for type and variable name
* @len: the max-length of @buf
*
* Get the name and type of @vr_die and stores it in @buf as "type\tname".
*/
int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
{
int ret, ret2;
ret = die_get_typename(vr_die, buf, len);
if (ret < 0) {
pr_debug("Failed to get type, make it unknown.\n");
ret = snprintf(buf, len, "(unknown_type)");
}
if (ret > 0) {
ret2 = snprintf(buf + ret, len - ret, "\t%s",
dwarf_diename(vr_die));
ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
}
return ret;
}