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path: root/tools/perf/util/unwind-libdw.c
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Diffstat (limited to 'tools/perf/util/unwind-libdw.c')
-rw-r--r--tools/perf/util/unwind-libdw.c63
1 files changed, 48 insertions, 15 deletions
diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c
index 2dcfe9a7c8d0..cf5e250bc78e 100644
--- a/tools/perf/util/unwind-libdw.c
+++ b/tools/perf/util/unwind-libdw.c
@@ -11,6 +11,7 @@
#include <linux/types.h>
#include "event.h"
#include "perf_regs.h"
+#include "callchain.h"
static char *debuginfo_path;
@@ -52,25 +53,28 @@ static int report_module(u64 ip, struct unwind_info *ui)
return __report_module(&al, ip, ui);
}
+/*
+ * Store all entries within entries array,
+ * we will process it after we finish unwind.
+ */
static int entry(u64 ip, struct unwind_info *ui)
{
- struct unwind_entry e;
+ struct unwind_entry *e = &ui->entries[ui->idx++];
struct addr_location al;
if (__report_module(&al, ip, ui))
return -1;
- e.ip = ip;
- e.map = al.map;
- e.sym = al.sym;
+ e->ip = ip;
+ e->map = al.map;
+ e->sym = al.sym;
pr_debug("unwind: %s:ip = 0x%" PRIx64 " (0x%" PRIx64 ")\n",
al.sym ? al.sym->name : "''",
ip,
al.map ? al.map->map_ip(al.map, ip) : (u64) 0);
-
- return ui->cb(&e, ui->arg);
+ return 0;
}
static pid_t next_thread(Dwfl *dwfl, void *arg, void **thread_argp)
@@ -92,6 +96,16 @@ static int access_dso_mem(struct unwind_info *ui, Dwarf_Addr addr,
thread__find_addr_map(ui->thread, PERF_RECORD_MISC_USER,
MAP__FUNCTION, addr, &al);
if (!al.map) {
+ /*
+ * We've seen cases (softice) where DWARF unwinder went
+ * through non executable mmaps, which we need to lookup
+ * in MAP__VARIABLE tree.
+ */
+ thread__find_addr_map(ui->thread, PERF_RECORD_MISC_USER,
+ MAP__VARIABLE, addr, &al);
+ }
+
+ if (!al.map) {
pr_debug("unwind: no map for %lx\n", (unsigned long)addr);
return -1;
}
@@ -168,7 +182,7 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
struct perf_sample *data,
int max_stack)
{
- struct unwind_info ui = {
+ struct unwind_info *ui, ui_buf = {
.sample = data,
.thread = thread,
.machine = thread->mg->machine,
@@ -177,35 +191,54 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
.max_stack = max_stack,
};
Dwarf_Word ip;
- int err = -EINVAL;
+ int err = -EINVAL, i;
if (!data->user_regs.regs)
return -EINVAL;
- ui.dwfl = dwfl_begin(&offline_callbacks);
- if (!ui.dwfl)
+ ui = zalloc(sizeof(ui_buf) + sizeof(ui_buf.entries[0]) * max_stack);
+ if (!ui)
+ return -ENOMEM;
+
+ *ui = ui_buf;
+
+ ui->dwfl = dwfl_begin(&offline_callbacks);
+ if (!ui->dwfl)
goto out;
err = perf_reg_value(&ip, &data->user_regs, PERF_REG_IP);
if (err)
goto out;
- err = report_module(ip, &ui);
+ err = report_module(ip, ui);
if (err)
goto out;
- if (!dwfl_attach_state(ui.dwfl, EM_NONE, thread->tid, &callbacks, &ui))
+ if (!dwfl_attach_state(ui->dwfl, EM_NONE, thread->tid, &callbacks, ui))
goto out;
- err = dwfl_getthread_frames(ui.dwfl, thread->tid, frame_callback, &ui);
+ err = dwfl_getthread_frames(ui->dwfl, thread->tid, frame_callback, ui);
- if (err && !ui.max_stack)
+ if (err && !ui->max_stack)
err = 0;
+ /*
+ * Display what we got based on the order setup.
+ */
+ for (i = 0; i < ui->idx && !err; i++) {
+ int j = i;
+
+ if (callchain_param.order == ORDER_CALLER)
+ j = ui->idx - i - 1;
+
+ err = ui->entries[j].ip ? ui->cb(&ui->entries[j], ui->arg) : 0;
+ }
+
out:
if (err)
pr_debug("unwind: failed with '%s'\n", dwfl_errmsg(-1));
- dwfl_end(ui.dwfl);
+ dwfl_end(ui->dwfl);
+ free(ui);
return 0;
}