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Subject[PATCH -tip v2 7/8] perf probe: Remove die() from probe-finder code
Date
Remove die() and DIE_IF() code from util/probe-finder.c since
these 'sudden death' in utility functions make reusing it from
other code (especially tui/gui) difficult.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
---
tools/perf/util/probe-event.c | 4
tools/perf/util/probe-finder.c | 517 +++++++++++++++++++++++++---------------
2 files changed, 322 insertions(+), 199 deletions(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index bef2805..7893b32 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -151,10 +151,10 @@ static int try_to_find_kprobe_trace_events(struct perf_probe_event *pev,

/* Error path */
if (need_dwarf) {
- if (ntevs == -ENOENT)
+ if (ntevs == -EBADF)
pr_warning("No dwarf info found in the vmlinux - "
"please rebuild with CONFIG_DEBUG_INFO=y.\n");
- die("Could not analyze debuginfo.");
+ die("Failed to analyze debuginfo.");
}
pr_debug("An error occurred in debuginfo analysis."
" Try to use symbols.\n");
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 1f45285..4a57504 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -196,19 +196,7 @@ static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
{
const char *name;
name = dwarf_diename(dw_die);
- DIE_IF(name == NULL);
- return strcmp(tname, name);
-}
-
-/* Get entry pc(or low pc, 1st entry of ranges) of the die */
-static Dwarf_Addr die_get_entrypc(Dwarf_Die *dw_die)
-{
- Dwarf_Addr epc;
- int ret;
-
- ret = dwarf_entrypc(dw_die, &epc);
- DIE_IF(ret == -1);
- return epc;
+ return name ? strcmp(tname, name) : -1;
}

/* Get type die, but skip qualifiers and typedef */
@@ -390,7 +378,7 @@ static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
*/

/* Show a location */
-static void convert_location(Dwarf_Op *op, struct probe_finder *pf)
+static int convert_location(Dwarf_Op *op, struct probe_finder *pf)
{
unsigned int regn;
Dwarf_Word offs = 0;
@@ -400,8 +388,11 @@ static void convert_location(Dwarf_Op *op, struct probe_finder *pf)

/* If this is based on frame buffer, set the offset */
if (op->atom == DW_OP_fbreg) {
- if (pf->fb_ops == NULL)
- die("The attribute of frame base is not supported.\n");
+ if (pf->fb_ops == NULL) {
+ pr_warning("The attribute of frame base is not "
+ "supported.\n");
+ return -ENOTSUP;
+ }
ref = true;
offs = op->number;
op = &pf->fb_ops[0];
@@ -419,50 +410,63 @@ static void convert_location(Dwarf_Op *op, struct probe_finder *pf)
ref = true;
} else if (op->atom == DW_OP_regx) {
regn = op->number;
- } else
- die("DW_OP %d is not supported.", op->atom);
+ } else {
+ pr_warning("DW_OP %d is not supported.\n", op->atom);
+ return -ENOTSUP;
+ }

regs = get_arch_regstr(regn);
- if (!regs)
- die("%u exceeds max register number.", regn);
+ if (!regs) {
+ pr_warning("%u exceeds max register number.\n", regn);
+ return -ERANGE;
+ }

tvar->value = xstrdup(regs);
if (ref) {
tvar->ref = xzalloc(sizeof(struct kprobe_trace_arg_ref));
tvar->ref->offset = (long)offs;
}
+ return 0;
}

-static void convert_variable_type(Dwarf_Die *vr_die,
- struct kprobe_trace_arg *targ)
+static int convert_variable_type(Dwarf_Die *vr_die,
+ struct kprobe_trace_arg *targ)
{
Dwarf_Die type;
char buf[16];
int ret;

- if (die_get_real_type(vr_die, &type) == NULL)
- die("Failed to get a type information of %s.",
- dwarf_diename(vr_die));
+ 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;
+ }

ret = die_get_byte_size(&type) * 8;
if (ret) {
/* Check the bitwidth */
if (ret > MAX_BASIC_TYPE_BITS) {
- pr_warning(" Warning: %s exceeds max-bitwidth."
- " Cut down to %d bits.\n",
- dwarf_diename(&type), 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);
- if (ret < 0 || ret >= 16)
- die("Failed to convert variable type.");
+ if (ret < 0 || ret >= 16) {
+ if (ret >= 16)
+ ret = -E2BIG;
+ pr_warning("Failed to convert variable type: %s\n",
+ strerror(-ret));
+ return ret;
+ }
targ->type = xstrdup(buf);
}
+ return 0;
}

-static void convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
+static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
struct perf_probe_arg_field *field,
struct kprobe_trace_arg_ref **ref_ptr,
Dwarf_Die *die_mem)
@@ -473,21 +477,28 @@ static void convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
Dwarf_Word offs;

pr_debug("converting %s in %s\n", field->name, varname);
- if (die_get_real_type(vr_die, &type) == NULL)
- die("Failed to get a type information of %s.", varname);
+ if (die_get_real_type(vr_die, &type) == NULL) {
+ pr_warning("Failed to get the type of %s.\n", varname);
+ return -ENOENT;
+ }

/* Check the pointer and dereference */
if (dwarf_tag(&type) == DW_TAG_pointer_type) {
- if (!field->ref)
- die("Semantic error: %s must be referred by '->'",
- field->name);
+ 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)
- die("Failed to get a type information of %s.", varname);
-
+ 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)
- die("%s is not a data structure.", varname);
+ if (dwarf_tag(&type) != DW_TAG_structure_type) {
+ pr_warning("%s is not a data structure.\n", varname);
+ return -EINVAL;
+ }

ref = xzalloc(sizeof(struct kprobe_trace_arg_ref));
if (*ref_ptr)
@@ -496,34 +507,46 @@ static void convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
*ref_ptr = ref;
} else {
/* Verify it is a data structure */
- if (dwarf_tag(&type) != DW_TAG_structure_type)
- die("%s is not a data structure.", varname);
-
- if (field->ref)
- die("Semantic error: %s must be referred by '.'",
- field->name);
- if (!ref)
- die("Structure on a register is not supported yet.");
+ if (dwarf_tag(&type) != DW_TAG_structure_type) {
+ pr_warning("%s is not a data structure.\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)
- die("%s(tyep:%s) has no member %s.", varname,
- dwarf_diename(&type), field->name);
+ 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 */
if (dwarf_attr(die_mem, DW_AT_data_member_location, &attr) == NULL ||
- dwarf_formudata(&attr, &offs) != 0)
- die("Failed to get the offset of %s.", field->name);
+ dwarf_formudata(&attr, &offs) != 0) {
+ pr_warning("Failed to get the offset of %s.\n", field->name);
+ return -ENOENT;
+ }
ref->offset += (long)offs;

/* Converting next field */
if (field->next)
- convert_variable_fields(die_mem, field->name, field->next,
- &ref, die_mem);
+ return convert_variable_fields(die_mem, field->name,
+ field->next, &ref, die_mem);
+ else
+ return 0;
}

/* Show a variables in kprobe event format */
-static void convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
+static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
{
Dwarf_Attribute attr;
Dwarf_Die die_mem;
@@ -538,28 +561,30 @@ static void convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
if (ret <= 0 || nexpr == 0)
goto error;

- convert_location(expr, pf);
-
- if (pf->pvar->field) {
- convert_variable_fields(vr_die, pf->pvar->var,
- pf->pvar->field, &pf->tvar->ref,
- &die_mem);
+ ret = convert_location(expr, pf);
+ if (ret == 0 && 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 (pf->pvar->type)
- pf->tvar->type = xstrdup(pf->pvar->type);
- else
- convert_variable_type(vr_die, pf->tvar);
+ if (ret == 0) {
+ if (pf->pvar->type)
+ pf->tvar->type = xstrdup(pf->pvar->type);
+ else
+ ret = convert_variable_type(vr_die, pf->tvar);
+ }
/* *expr will be cached in libdw. Don't free it. */
- return ;
+ return ret;
error:
/* TODO: Support const_value */
- die("Failed to find the location of %s at this address.\n"
- " Perhaps, it has been optimized out.", pf->pvar->var);
+ pr_err("Failed to find the location of %s at this address.\n"
+ " Perhaps, it has been optimized out.\n", pf->pvar->var);
+ return -ENOENT;
}

/* Find a variable in a subprogram die */
-static void find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
+static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
{
Dwarf_Die vr_die;
char buf[32], *ptr;
@@ -578,19 +603,22 @@ static void find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
if (!is_c_varname(pf->pvar->var)) {
/* Copy raw parameters */
pf->tvar->value = xstrdup(pf->pvar->var);
- } else {
- pr_debug("Searching '%s' variable in context.\n",
- pf->pvar->var);
- /* Search child die for local variables and parameters. */
- if (!die_find_variable(sp_die, pf->pvar->var, &vr_die))
- die("Failed to find '%s' in this function.",
- pf->pvar->var);
- convert_variable(&vr_die, pf);
+ return 0;
}
+
+ pr_debug("Searching '%s' variable in context.\n",
+ pf->pvar->var);
+ /* Search child die for local variables and parameters. */
+ if (!die_find_variable(sp_die, pf->pvar->var, &vr_die)) {
+ pr_warning("Failed to find '%s' in this function.\n",
+ pf->pvar->var);
+ return -ENOENT;
+ }
+ return convert_variable(&vr_die, pf);
}

/* Show a probe point to output buffer */
-static void convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
+static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
{
struct kprobe_trace_event *tev;
Dwarf_Addr eaddr;
@@ -600,22 +628,31 @@ static void convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
Dwarf_Attribute fb_attr;
size_t nops;

- if (pf->ntevs == MAX_PROBES)
- die("Too many( > %d) probe point found.\n", MAX_PROBES);
+ if (pf->ntevs == MAX_PROBES) {
+ pr_warning("Too many( > %d) probe point found.\n", MAX_PROBES);
+ return -ERANGE;
+ }
tev = &pf->tevs[pf->ntevs++];

/* 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)
- die("Probe point is not found in subprograms.");
+ if (!sp_die) {
+ pr_warning("Failed to find probe point in any "
+ "functions.\n");
+ return -ENOENT;
+ }
}

/* Copy the name of probe point */
name = dwarf_diename(sp_die);
if (name) {
- dwarf_entrypc(sp_die, &eaddr);
+ if (dwarf_entrypc(sp_die, &eaddr) != 0) {
+ pr_warning("Failed to get entry pc of %s\n",
+ dwarf_diename(sp_die));
+ return -ENOENT;
+ }
tev->point.symbol = xstrdup(name);
tev->point.offset = (unsigned long)(pf->addr - eaddr);
} else
@@ -633,9 +670,12 @@ static void convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
} else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
pf->cfi != NULL) {
Dwarf_Frame *frame;
- ret = dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame);
- DIE_IF(ret != 0);
- dwarf_frame_cfa(frame, &pf->fb_ops, &nops);
+ if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
+ dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
+ pr_warning("Failed to get CFA on 0x%jx\n",
+ (uintmax_t)pf->addr);
+ return -ENOENT;
+ }
}

/* Find each argument */
@@ -644,45 +684,53 @@ static void convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
for (i = 0; i < pf->pev->nargs; i++) {
pf->pvar = &pf->pev->args[i];
pf->tvar = &tev->args[i];
- find_variable(sp_die, pf);
+ ret = find_variable(sp_die, pf);
+ if (ret != 0)
+ return ret;
}

/* *pf->fb_ops will be cached in libdw. Don't free it. */
pf->fb_ops = NULL;
+ return 0;
}

/* Find probe point from its line number */
-static void find_probe_point_by_line(struct probe_finder *pf)
+static int find_probe_point_by_line(struct probe_finder *pf)
{
Dwarf_Lines *lines;
Dwarf_Line *line;
size_t nlines, i;
Dwarf_Addr addr;
int lineno;
- int ret;
+ int ret = 0;

- ret = dwarf_getsrclines(&pf->cu_die, &lines, &nlines);
- DIE_IF(ret != 0);
+ if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
+ pr_warning("No source lines found in this CU.\n");
+ return -ENOENT;
+ }

- for (i = 0; i < nlines; i++) {
+ for (i = 0; i < nlines && ret == 0; i++) {
line = dwarf_onesrcline(lines, i);
- dwarf_lineno(line, &lineno);
- if (lineno != pf->lno)
+ if (dwarf_lineno(line, &lineno) != 0 ||
+ lineno != pf->lno)
continue;

/* TODO: Get fileno from line, but how? */
if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
continue;

- ret = dwarf_lineaddr(line, &addr);
- DIE_IF(ret != 0);
+ if (dwarf_lineaddr(line, &addr) != 0) {
+ pr_warning("Failed to get the address of the line.\n");
+ return -ENOENT;
+ }
pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
(int)i, lineno, (uintmax_t)addr);
pf->addr = addr;

- convert_probe_point(NULL, pf);
+ ret = convert_probe_point(NULL, pf);
/* Continuing, because target line might be inlined. */
}
+ return ret;
}

/* Find lines which match lazy pattern */
@@ -690,15 +738,27 @@ static int find_lazy_match_lines(struct list_head *head,
const char *fname, const char *pat)
{
char *fbuf, *p1, *p2;
- int fd, line, nlines = 0;
+ int fd, ret, line, nlines = 0;
struct stat st;

fd = open(fname, O_RDONLY);
- if (fd < 0)
- die("failed to open %s", fname);
- DIE_IF(fstat(fd, &st) < 0);
+ if (fd < 0) {
+ pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
+ return fd;
+ }
+
+ ret = fstat(fd, &st);
+ if (ret < 0) {
+ pr_warning("Failed to get the size of %s: %s\n",
+ fname, strerror(errno));
+ return ret;
+ }
fbuf = xmalloc(st.st_size + 2);
- DIE_IF(read(fd, fbuf, st.st_size) < 0);
+ ret = read(fd, fbuf, st.st_size);
+ if (ret < 0) {
+ pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
+ return ret;
+ }
close(fd);
fbuf[st.st_size] = '\n'; /* Dummy line */
fbuf[st.st_size + 1] = '\0';
@@ -718,7 +778,7 @@ static int find_lazy_match_lines(struct list_head *head,
}

/* Find probe points from lazy pattern */
-static void find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
+static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
{
Dwarf_Lines *lines;
Dwarf_Line *line;
@@ -726,31 +786,40 @@ static void find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
Dwarf_Addr addr;
Dwarf_Die die_mem;
int lineno;
- int ret;
+ 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)
- die("No matched lines found in %s.", pf->fname);
+ if (ret == 0) {
+ pr_debug("No matched lines found in %s.\n", pf->fname);
+ return 0;
+ } else if (ret < 0)
+ return ret;
}

- ret = dwarf_getsrclines(&pf->cu_die, &lines, &nlines);
- DIE_IF(ret != 0);
- for (i = 0; i < nlines; i++) {
+ if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
+ pr_warning("No source lines found in this CU.\n");
+ return -ENOENT;
+ }
+
+ for (i = 0; i < nlines && ret >= 0; i++) {
line = dwarf_onesrcline(lines, i);

- dwarf_lineno(line, &lineno);
- if (!line_list__has_line(&pf->lcache, lineno))
+ if (dwarf_lineno(line, &lineno) != 0 ||
+ !line_list__has_line(&pf->lcache, lineno))
continue;

/* TODO: Get fileno from line, but how? */
if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
continue;

- ret = dwarf_lineaddr(line, &addr);
- DIE_IF(ret != 0);
+ if (dwarf_lineaddr(line, &addr) != 0) {
+ pr_debug("Failed to get the address of line %d.\n",
+ lineno);
+ continue;
+ }
if (sp_die) {
/* Address filtering 1: does sp_die include addr? */
if (!dwarf_haspc(sp_die, addr))
@@ -764,27 +833,42 @@ static void find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
(int)i, lineno, (unsigned long long)addr);
pf->addr = addr;

- convert_probe_point(sp_die, pf);
+ ret = convert_probe_point(sp_die, pf);
/* Continuing, because target line might be inlined. */
}
/* TODO: deallocate lines, but how? */
+ return ret;
}

+/* 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 probe_finder *pf = (struct probe_finder *)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)
- find_probe_point_lazy(in_die, pf);
+ param->retval = find_probe_point_lazy(in_die, pf);
else {
/* Get probe address */
- pf->addr = die_get_entrypc(in_die);
+ if (dwarf_entrypc(in_die, &addr) != 0) {
+ pr_warning("Failed to get entry pc 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);

- convert_probe_point(in_die, pf);
+ param->retval = convert_probe_point(in_die, pf);
}

return DWARF_CB_OK;
@@ -793,39 +877,53 @@ static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
/* Search function from function name */
static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
{
- struct probe_finder *pf = (struct probe_finder *)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) != 0)
- return 0;
+ 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;
- find_probe_point_by_line(pf);
+ param->retval = find_probe_point_by_line(pf);
} else if (!dwarf_func_inline(sp_die)) {
/* Real function */
if (pp->lazy_line)
- find_probe_point_lazy(sp_die, pf);
+ param->retval = find_probe_point_lazy(sp_die, pf);
else {
- pf->addr = die_get_entrypc(sp_die);
+ if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
+ pr_warning("Failed to get entry pc 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 */
- convert_probe_point(sp_die, pf);
+ param->retval = convert_probe_point(sp_die, pf);
}
- } else
+ } 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, pf);
+ dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
+ &_param);
+ param->retval = _param.retval;
+ }

- return 1; /* Exit; no same symbol in this CU. */
+ return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
}

-static void find_probe_point_by_func(struct probe_finder *pf)
+static int find_probe_point_by_func(struct probe_finder *pf)
{
- dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, pf, 0);
+ struct dwarf_callback_param _param = {.data = (void *)pf,
+ .retval = 0};
+ dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
+ return _param.retval;
}

/* Find kprobe_trace_events specified by perf_probe_event from debuginfo */
@@ -838,14 +936,18 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
size_t cuhl;
Dwarf_Die *diep;
Dwarf *dbg;
+ int ret = 0;

pf.tevs = xzalloc(sizeof(struct kprobe_trace_event) * MAX_PROBES);
*tevs = pf.tevs;
pf.ntevs = 0;

dbg = dwarf_begin(fd, DWARF_C_READ);
- if (!dbg)
- return -ENOENT;
+ if (!dbg) {
+ pr_warning("No dwarf info found in the vmlinux - "
+ "please rebuild with CONFIG_DEBUG_INFO=y.\n");
+ return -EBADF;
+ }

/* Get the call frame information from this dwarf */
pf.cfi = dwarf_getcfi(dbg);
@@ -853,7 +955,8 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
off = 0;
line_list__init(&pf.lcache);
/* Loop on CUs (Compilation Unit) */
- while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
+ while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
+ ret >= 0) {
/* Get the DIE(Debugging Information Entry) of this CU */
diep = dwarf_offdie(dbg, off + cuhl, &pf.cu_die);
if (!diep)
@@ -867,12 +970,12 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,

if (!pp->file || pf.fname) {
if (pp->function)
- find_probe_point_by_func(&pf);
+ ret = find_probe_point_by_func(&pf);
else if (pp->lazy_line)
- find_probe_point_lazy(NULL, &pf);
+ ret = find_probe_point_lazy(NULL, &pf);
else {
pf.lno = pp->line;
- find_probe_point_by_line(&pf);
+ ret = find_probe_point_by_line(&pf);
}
}
off = noff;
@@ -880,7 +983,7 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
line_list__free(&pf.lcache);
dwarf_end(dbg);

- return pf.ntevs;
+ return (ret < 0) ? ret : pf.ntevs;
}

/* Reverse search */
@@ -893,10 +996,11 @@ int find_perf_probe_point(int fd, unsigned long addr,
Dwarf_Addr laddr, eaddr;
const char *tmp;
int lineno, ret = 0;
+ bool found = false;

dbg = dwarf_begin(fd, DWARF_C_READ);
if (!dbg)
- return -ENOENT;
+ return -EBADF;

/* Find cu die */
if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) {
@@ -907,82 +1011,87 @@ int find_perf_probe_point(int fd, unsigned long addr,
/* Find a corresponding line */
line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
if (line) {
- dwarf_lineaddr(line, &laddr);
- if ((Dwarf_Addr)addr == laddr) {
- dwarf_lineno(line, &lineno);
- ppt->line = lineno;
-
+ if (dwarf_lineaddr(line, &laddr) == 0 &&
+ (Dwarf_Addr)addr == laddr &&
+ dwarf_lineno(line, &lineno) == 0) {
tmp = dwarf_linesrc(line, NULL, NULL);
- DIE_IF(!tmp);
- ppt->file = xstrdup(tmp);
- ret = 1;
+ if (tmp) {
+ ppt->line = lineno;
+ ppt->file = xstrdup(tmp);
+ found = true;
+ }
}
}

/* Find a corresponding function */
if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
tmp = dwarf_diename(&spdie);
- if (!tmp)
+ if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
goto end;

- dwarf_entrypc(&spdie, &eaddr);
- if (!lineno) {
- /* We don't have a line number, let's use offset */
- ppt->function = xstrdup(tmp);
- ppt->offset = addr - (unsigned long)eaddr;
- ret = 1;
- goto end;
- }
- if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr, &indie)) {
- /* addr in an inline function */
- tmp = dwarf_diename(&indie);
- if (!tmp)
- goto end;
- dwarf_decl_line(&indie, &lineno);
- } else {
- if (eaddr == addr) /* No offset: function entry */
- lineno = ppt->line;
- else
- dwarf_decl_line(&spdie, &lineno);
+ if (ppt->line) {
+ if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
+ &indie)) {
+ /* addr in an inline function */
+ tmp = dwarf_diename(&indie);
+ if (!tmp)
+ goto end;
+ ret = dwarf_decl_line(&indie, &lineno);
+ } else {
+ if (eaddr == addr) { /* Function entry */
+ lineno = ppt->line;
+ ret = 0;
+ } else
+ ret = dwarf_decl_line(&spdie, &lineno);
+ }
+ if (ret == 0) {
+ /* Make a relative line number */
+ ppt->line -= lineno;
+ goto found;
+ }
}
+ /* We don't have a line number, let's use offset */
+ ppt->offset = addr - (unsigned long)eaddr;
+found:
ppt->function = xstrdup(tmp);
- ppt->line -= lineno; /* Make a relative line number */
+ found = true;
}

end:
dwarf_end(dbg);
+ if (ret >= 0)
+ ret = found ? 1 : 0;
return ret;
}


/* Find line range from its line number */
-static void find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
+static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
{
Dwarf_Lines *lines;
Dwarf_Line *line;
size_t nlines, i;
Dwarf_Addr addr;
int lineno;
- int ret;
const char *src;
Dwarf_Die die_mem;

line_list__init(&lf->lr->line_list);
- ret = dwarf_getsrclines(&lf->cu_die, &lines, &nlines);
- DIE_IF(ret != 0);
+ if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
+ pr_warning("No source lines found in this CU.\n");
+ return -ENOENT;
+ }

for (i = 0; i < nlines; i++) {
line = dwarf_onesrcline(lines, i);
- ret = dwarf_lineno(line, &lineno);
- DIE_IF(ret != 0);
- if (lf->lno_s > lineno || lf->lno_e < lineno)
+ if (dwarf_lineno(line, &lineno) != 0 ||
+ (lf->lno_s > lineno || lf->lno_e < lineno))
continue;

if (sp_die) {
/* Address filtering 1: does sp_die include addr? */
- ret = dwarf_lineaddr(line, &addr);
- DIE_IF(ret != 0);
- if (!dwarf_haspc(sp_die, addr))
+ if (dwarf_lineaddr(line, &addr) != 0 ||
+ !dwarf_haspc(sp_die, addr))
continue;

/* Address filtering 2: No child include addr? */
@@ -1007,18 +1116,22 @@ static void find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
free(lf->lr->path);
lf->lr->path = NULL;
}
+ return lf->found;
}

static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
{
- find_line_range_by_line(in_die, (struct line_finder *)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 line_finder *lf = (struct line_finder *)data;
+ struct dwarf_callback_param *param = data;
+ struct line_finder *lf = param->data;
struct line_range *lr = lf->lr;

if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
@@ -1033,38 +1146,47 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
lf->lno_e = lr->offset + lr->end;
lr->start = lf->lno_s;
lr->end = lf->lno_e;
- if (dwarf_func_inline(sp_die))
+ 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, lf);
- else
- find_line_range_by_line(sp_die, lf);
- return 1;
+ 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 0;
+ return DWARF_CB_OK;
}

-static void find_line_range_by_func(struct line_finder *lf)
+static int find_line_range_by_func(struct line_finder *lf)
{
- dwarf_getfuncs(&lf->cu_die, line_range_search_cb, lf, 0);
+ 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;
+ int ret = 0;
Dwarf_Off off = 0, noff;
size_t cuhl;
Dwarf_Die *diep;
Dwarf *dbg;

dbg = dwarf_begin(fd, DWARF_C_READ);
- if (!dbg)
- return -ENOENT;
+ if (!dbg) {
+ pr_warning("No dwarf info found in the vmlinux - "
+ "please rebuild with CONFIG_DEBUG_INFO=y.\n");
+ return -EBADF;
+ }

/* Loop on CUs (Compilation Unit) */
- while (!lf.found) {
- ret = dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL);
- if (ret != 0)
+ 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 */
@@ -1080,20 +1202,21 @@ int find_line_range(int fd, struct line_range *lr)

if (!lr->file || lf.fname) {
if (lr->function)
- find_line_range_by_func(&lf);
+ ret = find_line_range_by_func(&lf);
else {
lf.lno_s = lr->start;
if (!lr->end)
lf.lno_e = INT_MAX;
else
lf.lno_e = lr->end;
- find_line_range_by_line(NULL, &lf);
+ ret = find_line_range_by_line(NULL, &lf);
}
}
off = noff;
}
pr_debug("path: %lx\n", (unsigned long)lr->path);
dwarf_end(dbg);
- return lf.found;
+
+ return (ret < 0) ? ret : lf.found;
}


--
Masami Hiramatsu
e-mail: mhiramat@redhat.com


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