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path: root/kernel/tools/perf/util/probe-finder.c
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Diffstat (limited to 'kernel/tools/perf/util/probe-finder.c')
-rw-r--r--kernel/tools/perf/util/probe-finder.c266
1 files changed, 185 insertions, 81 deletions
diff --git a/kernel/tools/perf/util/probe-finder.c b/kernel/tools/perf/util/probe-finder.c
index 2a76e14db..05012bb17 100644
--- a/kernel/tools/perf/util/probe-finder.c
+++ b/kernel/tools/perf/util/probe-finder.c
@@ -70,6 +70,7 @@ static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
if (!dbg->dwfl)
goto error;
+ dwfl_report_begin(dbg->dwfl);
dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd);
if (!dbg->mod)
goto error;
@@ -78,6 +79,8 @@ static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
if (!dbg->dbg)
goto error;
+ dwfl_report_end(dbg->dwfl, NULL, NULL);
+
return 0;
error:
if (dbg->dwfl)
@@ -130,7 +133,7 @@ struct debuginfo *debuginfo__new(const char *path)
continue;
dinfo = __debuginfo__new(buf);
}
- dso__delete(dso);
+ dso__put(dso);
out:
/* if failed to open all distro debuginfo, open given binary */
@@ -177,7 +180,7 @@ static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
Dwarf_Word offs = 0;
bool ref = false;
const char *regs;
- int ret;
+ int ret, ret2 = 0;
if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
goto static_var;
@@ -187,9 +190,19 @@ static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
return -EINVAL; /* Broken DIE ? */
if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) {
ret = dwarf_entrypc(sp_die, &tmp);
- if (ret || addr != tmp ||
- dwarf_tag(vr_die) != DW_TAG_formal_parameter ||
- dwarf_highpc(sp_die, &tmp))
+ if (ret)
+ return -ENOENT;
+
+ if (probe_conf.show_location_range &&
+ (dwarf_tag(vr_die) == DW_TAG_variable)) {
+ ret2 = -ERANGE;
+ } else if (addr != tmp ||
+ dwarf_tag(vr_die) != DW_TAG_formal_parameter) {
+ return -ENOENT;
+ }
+
+ ret = dwarf_highpc(sp_die, &tmp);
+ if (ret)
return -ENOENT;
/*
* This is fuzzed by fentry mcount. We try to find the
@@ -210,7 +223,7 @@ found:
if (op->atom == DW_OP_addr) {
static_var:
if (!tvar)
- return 0;
+ return ret2;
/* Static variables on memory (not stack), make @varname */
ret = strlen(dwarf_diename(vr_die));
tvar->value = zalloc(ret + 2);
@@ -220,7 +233,7 @@ static_var:
tvar->ref = alloc_trace_arg_ref((long)offs);
if (tvar->ref == NULL)
return -ENOMEM;
- return 0;
+ return ret2;
}
/* If this is based on frame buffer, set the offset */
@@ -250,14 +263,14 @@ static_var:
}
if (!tvar)
- return 0;
+ return ret2;
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;
+ return -ENOTSUP;
}
tvar->value = strdup(regs);
@@ -269,7 +282,7 @@ static_var:
if (tvar->ref == NULL)
return -ENOMEM;
}
- return 0;
+ return ret2;
}
#define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
@@ -517,10 +530,12 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
&pf->sp_die, pf->tvar);
- if (ret == -ENOENT || ret == -EINVAL)
- 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)
+ if (ret == -ENOENT || ret == -EINVAL) {
+ pr_err("Failed to find the location of the '%s' variable at this address.\n"
+ " Perhaps it has been optimized out.\n"
+ " Use -V with the --range option to show '%s' location range.\n",
+ pf->pvar->var, pf->pvar->var);
+ } else if (ret == -ENOTSUP)
pr_err("Sorry, we don't support this variable location yet.\n");
else if (ret == 0 && pf->pvar->field) {
ret = convert_variable_fields(vr_die, pf->pvar->var,
@@ -541,24 +556,9 @@ static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
char buf[32], *ptr;
int ret = 0;
- 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;
- }
+ /* Copy raw parameters */
+ if (!is_c_varname(pf->pvar->var))
+ return copy_to_probe_trace_arg(pf->tvar, pf->pvar);
if (pf->pvar->name)
pf->tvar->name = strdup(pf->pvar->name);
@@ -594,6 +594,7 @@ static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
/* Convert subprogram DIE to trace point */
static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
Dwarf_Addr paddr, bool retprobe,
+ const char *function,
struct probe_trace_point *tp)
{
Dwarf_Addr eaddr, highaddr;
@@ -637,8 +638,10 @@ static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
/* 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");
+ pr_warning("Failed to find \"%s%%return\",\n"
+ " because %s is an inlined function and"
+ " has no return point.\n", function,
+ function);
return -EINVAL;
}
tp->retprobe = true;
@@ -662,9 +665,15 @@ static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
/* If not a real subprogram, find a real one */
if (!die_is_func_def(sc_die)) {
if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
- pr_warning("Failed to find probe point in any "
- "functions.\n");
- return -ENOENT;
+ if (die_find_tailfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
+ pr_warning("Ignoring tail call from %s\n",
+ dwarf_diename(&pf->sp_die));
+ return 0;
+ } else {
+ pr_warning("Failed to find probe point in any "
+ "functions.\n");
+ return -ENOENT;
+ }
}
} else
memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
@@ -719,7 +728,7 @@ static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
}
/* If the function name is given, that's what user expects */
if (fsp->function) {
- if (die_compare_name(fn_die, fsp->function)) {
+ if (die_match_name(fn_die, fsp->function)) {
memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
fsp->found = true;
return 1;
@@ -922,13 +931,14 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
/* Check tag and diename */
if (!die_is_func_def(sp_die) ||
- !die_compare_name(sp_die, pp->function))
+ !die_match_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;
+ pr_debug("Matched function: %s\n", dwarf_diename(sp_die));
pf->fname = dwarf_decl_file(sp_die);
if (pp->line) { /* Function relative line */
dwarf_decl_line(sp_die, &pf->lno);
@@ -945,10 +955,20 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
/* TODO: Check the address in this function */
param->retval = call_probe_finder(sp_die, pf);
}
- } else
+ } else if (!probe_conf.no_inlines) {
/* Inlined function: search instances */
param->retval = die_walk_instances(sp_die,
probe_point_inline_cb, (void *)pf);
+ /* This could be a non-existed inline definition */
+ if (param->retval == -ENOENT && strisglob(pp->function))
+ param->retval = 0;
+ }
+
+ /* We need to find other candidates */
+ if (strisglob(pp->function) && param->retval >= 0) {
+ param->retval = 0; /* We have to clear the result */
+ return DWARF_CB_OK;
+ }
return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
}
@@ -977,7 +997,7 @@ static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
return DWARF_CB_OK;
- if (die_compare_name(param->sp_die, param->function)) {
+ if (die_match_name(param->sp_die, param->function)) {
if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
return DWARF_CB_OK;
@@ -1030,7 +1050,7 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
return -ENOMEM;
/* Fastpath: lookup by function name from .debug_pubnames section */
- if (pp->function) {
+ if (pp->function && !strisglob(pp->function)) {
struct pubname_callback_param pubname_param = {
.function = pp->function,
.file = pp->file,
@@ -1089,6 +1109,7 @@ found:
struct local_vars_finder {
struct probe_finder *pf;
struct perf_probe_arg *args;
+ bool vars;
int max_args;
int nargs;
int ret;
@@ -1103,7 +1124,7 @@ static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
tag = dwarf_tag(die_mem);
if (tag == DW_TAG_formal_parameter ||
- tag == DW_TAG_variable) {
+ (tag == DW_TAG_variable && vf->vars)) {
if (convert_variable_location(die_mem, vf->pf->addr,
vf->pf->fb_ops, &pf->sp_die,
NULL) == 0) {
@@ -1129,26 +1150,28 @@ static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
Dwarf_Die die_mem;
int i;
int n = 0;
- struct local_vars_finder vf = {.pf = pf, .args = args,
+ struct local_vars_finder vf = {.pf = pf, .args = args, .vars = false,
.max_args = MAX_PROBE_ARGS, .ret = 0};
for (i = 0; i < pf->pev->nargs; i++) {
/* var never be NULL */
- if (strcmp(pf->pev->args[i].var, "$vars") == 0) {
- pr_debug("Expanding $vars into:");
- vf.nargs = n;
- /* Special local variables */
- die_find_child(sc_die, copy_variables_cb, (void *)&vf,
- &die_mem);
- pr_debug(" (%d)\n", vf.nargs - n);
- if (vf.ret < 0)
- return vf.ret;
- n = vf.nargs;
- } else {
+ if (strcmp(pf->pev->args[i].var, PROBE_ARG_VARS) == 0)
+ vf.vars = true;
+ else if (strcmp(pf->pev->args[i].var, PROBE_ARG_PARAMS) != 0) {
/* Copy normal argument */
args[n] = pf->pev->args[i];
n++;
+ continue;
}
+ pr_debug("Expanding %s into:", pf->pev->args[i].var);
+ vf.nargs = n;
+ /* Special local variables */
+ die_find_child(sc_die, copy_variables_cb, (void *)&vf,
+ &die_mem);
+ pr_debug(" (%d)\n", vf.nargs - n);
+ if (vf.ret < 0)
+ return vf.ret;
+ n = vf.nargs;
}
return n;
}
@@ -1158,8 +1181,9 @@ static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
{
struct trace_event_finder *tf =
container_of(pf, struct trace_event_finder, pf);
+ struct perf_probe_point *pp = &pf->pev->point;
struct probe_trace_event *tev;
- struct perf_probe_arg *args;
+ struct perf_probe_arg *args = NULL;
int ret, i;
/* Check number of tevs */
@@ -1172,17 +1196,25 @@ static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
/* Trace point should be converted from subprogram DIE */
ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
- pf->pev->point.retprobe, &tev->point);
+ pp->retprobe, pp->function, &tev->point);
if (ret < 0)
- return ret;
+ goto end;
+
+ tev->point.realname = strdup(dwarf_diename(sc_die));
+ if (!tev->point.realname) {
+ ret = -ENOMEM;
+ goto end;
+ }
pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
tev->point.offset);
/* Expand special probe argument if exist */
args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
- if (args == NULL)
- return -ENOMEM;
+ if (args == NULL) {
+ ret = -ENOMEM;
+ goto end;
+ }
ret = expand_probe_args(sc_die, pf, args);
if (ret < 0)
@@ -1206,6 +1238,10 @@ static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
}
end:
+ if (ret) {
+ clear_probe_trace_event(tev);
+ tf->ntevs--;
+ }
free(args);
return ret;
}
@@ -1213,15 +1249,15 @@ end:
/* Find probe_trace_events specified by perf_probe_event from debuginfo */
int debuginfo__find_trace_events(struct debuginfo *dbg,
struct perf_probe_event *pev,
- struct probe_trace_event **tevs, int max_tevs)
+ struct probe_trace_event **tevs)
{
struct trace_event_finder tf = {
.pf = {.pev = pev, .callback = add_probe_trace_event},
- .mod = dbg->mod, .max_tevs = max_tevs};
- int ret;
+ .max_tevs = probe_conf.max_probes, .mod = dbg->mod};
+ int ret, i;
/* Allocate result tevs array */
- *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
+ *tevs = zalloc(sizeof(struct probe_trace_event) * tf.max_tevs);
if (*tevs == NULL)
return -ENOMEM;
@@ -1230,6 +1266,8 @@ int debuginfo__find_trace_events(struct debuginfo *dbg,
ret = debuginfo__find_probes(dbg, &tf.pf);
if (ret < 0) {
+ for (i = 0; i < tf.ntevs; i++)
+ clear_probe_trace_event(&tf.tevs[i]);
zfree(tevs);
return ret;
}
@@ -1237,14 +1275,11 @@ int debuginfo__find_trace_events(struct debuginfo *dbg,
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];
@@ -1255,11 +1290,38 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
ret = convert_variable_location(die_mem, af->pf.addr,
af->pf.fb_ops, &af->pf.sp_die,
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 (ret == 0 || ret == -ERANGE) {
+ int ret2;
+ bool externs = !af->child;
+ struct strbuf buf;
+
+ strbuf_init(&buf, 64);
+
+ if (probe_conf.show_location_range) {
+ if (!externs) {
+ if (ret)
+ strbuf_addf(&buf, "[INV]\t");
+ else
+ strbuf_addf(&buf, "[VAL]\t");
+ } else
+ strbuf_addf(&buf, "[EXT]\t");
+ }
+
+ ret2 = die_get_varname(die_mem, &buf);
+
+ if (!ret2 && probe_conf.show_location_range &&
+ !externs) {
+ strbuf_addf(&buf, "\t");
+ ret2 = die_get_var_range(&af->pf.sp_die,
+ die_mem, &buf);
+ }
+
+ pr_debug("Add new var: %s\n", buf.buf);
+ if (ret2 == 0) {
+ strlist__add(vl->vars,
+ strbuf_detach(&buf, NULL));
+ }
+ strbuf_release(&buf);
}
}
@@ -1274,6 +1336,7 @@ static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
{
struct available_var_finder *af =
container_of(pf, struct available_var_finder, pf);
+ struct perf_probe_point *pp = &pf->pev->point;
struct variable_list *vl;
Dwarf_Die die_mem;
int ret;
@@ -1287,7 +1350,7 @@ static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
/* Trace point should be converted from subprogram DIE */
ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
- pf->pev->point.retprobe, &vl->point);
+ pp->retprobe, pp->function, &vl->point);
if (ret < 0)
return ret;
@@ -1295,16 +1358,16 @@ static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
vl->point.offset);
/* Find local variables */
- vl->vars = strlist__new(true, NULL);
+ vl->vars = strlist__new(NULL, NULL);
if (vl->vars == NULL)
return -ENOMEM;
af->child = true;
die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
/* Find external variables */
- if (!af->externs)
+ if (!probe_conf.show_ext_vars)
goto out;
- /* Don't need to search child DIE for externs. */
+ /* Don't need to search child DIE for external vars. */
af->child = false;
die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
@@ -1324,17 +1387,16 @@ out:
*/
int debuginfo__find_available_vars_at(struct debuginfo *dbg,
struct perf_probe_event *pev,
- struct variable_list **vls,
- int max_vls, bool externs)
+ struct variable_list **vls)
{
struct available_var_finder af = {
.pf = {.pev = pev, .callback = add_available_vars},
.mod = dbg->mod,
- .max_vls = max_vls, .externs = externs};
+ .max_vls = probe_conf.max_probes};
int ret;
/* Allocate result vls array */
- *vls = zalloc(sizeof(struct variable_list) * max_vls);
+ *vls = zalloc(sizeof(struct variable_list) * af.max_vls);
if (*vls == NULL)
return -ENOMEM;
@@ -1355,6 +1417,41 @@ int debuginfo__find_available_vars_at(struct debuginfo *dbg,
return (ret < 0) ? ret : af.nvls;
}
+/* For the kernel module, we need a special code to get a DIE */
+static int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs)
+{
+ int n, i;
+ Elf32_Word shndx;
+ Elf_Scn *scn;
+ Elf *elf;
+ GElf_Shdr mem, *shdr;
+ const char *p;
+
+ elf = dwfl_module_getelf(dbg->mod, &dbg->bias);
+ if (!elf)
+ return -EINVAL;
+
+ /* Get the number of relocations */
+ n = dwfl_module_relocations(dbg->mod);
+ if (n < 0)
+ return -ENOENT;
+ /* Search the relocation related .text section */
+ for (i = 0; i < n; i++) {
+ p = dwfl_module_relocation_info(dbg->mod, i, &shndx);
+ if (strcmp(p, ".text") == 0) {
+ /* OK, get the section header */
+ scn = elf_getscn(elf, shndx);
+ if (!scn)
+ return -ENOENT;
+ shdr = gelf_getshdr(scn, &mem);
+ if (!shdr)
+ return -ENOENT;
+ *offs = shdr->sh_addr;
+ }
+ }
+ return 0;
+}
+
/* Reverse search */
int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
struct perf_probe_point *ppt)
@@ -1363,9 +1460,16 @@ int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
Dwarf_Addr _addr = 0, baseaddr = 0;
const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
int baseline = 0, lineno = 0, ret = 0;
+ bool reloc = false;
+retry:
/* Find cu die */
if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) {
+ if (!reloc && debuginfo__get_text_offset(dbg, &baseaddr) == 0) {
+ addr += baseaddr;
+ reloc = true;
+ goto retry;
+ }
pr_warning("Failed to find debug information for address %lx\n",
addr);
ret = -EINVAL;
@@ -1535,7 +1639,7 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
return DWARF_CB_OK;
if (die_is_func_def(sp_die) &&
- die_compare_name(sp_die, lr->function)) {
+ die_match_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);