eaac3dc7be
commit 07d369857808b7e8e471bbbbb0074a6718f89b31 upstream.
Since there are some DIE which has only ranges instead of the
combination of entrypc/highpc, address verification must use
dwarf_haspc() instead of dwarf_entrypc/dwarf_highpc.
Also, the ranges only DIE will have a partial code in different section
(e.g. unlikely code will be in text.unlikely as "FUNC.cold" symbol). In
that case, we can not use dwarf_entrypc() or die_entrypc(), because the
offset from original DIE can be a minus value.
Instead, this simply gets the symbol and offset from symtab.
Without this patch;
# perf probe -D clear_tasks_mm_cpumask:1
Failed to get entry address of clear_tasks_mm_cpumask
Error: Failed to add events.
And with this patch:
# perf probe -D clear_tasks_mm_cpumask:1
p:probe/clear_tasks_mm_cpumask clear_tasks_mm_cpumask+0
p:probe/clear_tasks_mm_cpumask_1 clear_tasks_mm_cpumask+5
p:probe/clear_tasks_mm_cpumask_2 clear_tasks_mm_cpumask+8
p:probe/clear_tasks_mm_cpumask_3 clear_tasks_mm_cpumask+16
p:probe/clear_tasks_mm_cpumask_4 clear_tasks_mm_cpumask+82
Committer testing:
I managed to reproduce the above:
[root@quaco ~]# perf probe -D clear_tasks_mm_cpumask:1
p:probe/clear_tasks_mm_cpumask _text+919968
p:probe/clear_tasks_mm_cpumask_1 _text+919973
p:probe/clear_tasks_mm_cpumask_2 _text+919976
[root@quaco ~]#
But then when trying to actually put the probe in place, it fails if I
use :0 as the offset:
[root@quaco ~]# perf probe -L clear_tasks_mm_cpumask | head -5
<clear_tasks_mm_cpumask@/usr/src/debug/kernel-5.2.fc30/linux-5.2.18-200.fc30.x86_64/kernel/cpu.c:0>
0 void clear_tasks_mm_cpumask(int cpu)
1 {
2 struct task_struct *p;
[root@quaco ~]# perf probe clear_tasks_mm_cpumask:0
Probe point 'clear_tasks_mm_cpumask' not found.
Error: Failed to add events.
[root@quaco
The next patch is needed to fix this case.
Fixes:
|
||
---|---|---|
.. | ||
arch | ||
bench | ||
Documentation | ||
examples/bpf | ||
include/bpf | ||
jvmti | ||
pmu-events | ||
python | ||
scripts | ||
tests | ||
trace | ||
ui | ||
util | ||
.gitignore | ||
Build | ||
builtin-annotate.c | ||
builtin-bench.c | ||
builtin-buildid-cache.c | ||
builtin-buildid-list.c | ||
builtin-c2c.c | ||
builtin-config.c | ||
builtin-data.c | ||
builtin-diff.c | ||
builtin-evlist.c | ||
builtin-ftrace.c | ||
builtin-help.c | ||
builtin-inject.c | ||
builtin-kallsyms.c | ||
builtin-kmem.c | ||
builtin-kvm.c | ||
builtin-list.c | ||
builtin-lock.c | ||
builtin-mem.c | ||
builtin-probe.c | ||
builtin-record.c | ||
builtin-report.c | ||
builtin-sched.c | ||
builtin-script.c | ||
builtin-stat.c | ||
builtin-timechart.c | ||
builtin-top.c | ||
builtin-trace.c | ||
builtin-version.c | ||
builtin.h | ||
check-headers.sh | ||
command-list.txt | ||
CREDITS | ||
design.txt | ||
Makefile | ||
Makefile.config | ||
Makefile.perf | ||
MANIFEST | ||
perf-archive.sh | ||
perf-completion.sh | ||
perf-read-vdso.c | ||
perf-sys.h | ||
perf-with-kcore.sh | ||
perf.c | ||
perf.h |