On Fri, 8 Dec 2023, Patrick Welche wrote:
When profiling my simulation with
dtrace -x ustackframes=100 -n 'profile-9 / execname == "mds" / { @[ustack()] =
count(); } tick-180s { exit(0); }' -o /tmp/out.stacks
every function name is preceded by c0 df ff ff 7f 7f e.g.,
00000060 20 20 20 20 20 20 20 20 20 c0 df ff ff 7f 7f 60 | ......`|
00000070 66 5f 70 61 69 72 5f 44 4c 56 4f 28 61 74 6f 6d |f_pair_DLVO(atom|
which is making perl, i.e., FlameGraph unhappy.
6 bytes seems a strange number.
Is this normal / any hints on what I can do about it?
This looks like junk on the stack:
src/external/cddl/osnet/dist/lib/libdtrace/common/dt_consume.c:dt_print_ustack()
doesn't initialize `objname' and doesn't check the return of proc_objname()
(line 1385) either.
Can you try this patch (fudged from FreeBSD)?
```
diff -urN a/src/external/bsd/libproc/dist/proc_sym.c
b/src/external/bsd/libproc/dist/proc_sym.c
--- a/src/external/bsd/libproc/dist/proc_sym.c 2017-06-16 00:44:58.000000000
+0100
+++ b/src/external/bsd/libproc/dist/proc_sym.c 2023-12-27 00:05:55.133763583
+0000
@@ -141,6 +141,10 @@
size_t i;
rd_loadobj_t *rdl;
+ if (p->nobjs == 0)
+ if (proc_rdagent(p) == NULL)
+ return (NULL);
+
for (i = 0; i < p->nobjs; i++) {
rdl = &p->rdobjs[i];
if (addr >= rdl->rdl_saddr && addr < rdl->rdl_eaddr) {
```
-RVP
