Messages in this thread Patch in this message |  | | From | Ravi Bangoria <> | Subject | [PATCH] perf uretprobe ppc64le: Fix probe location | Date | Tue, 4 Oct 2016 15:57:45 +0530 |
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Perf uretprobe probes on GEP(Glabal Entry Point) which fails to record all function calls via LEP(Local Entry Point). Fix that by probing on LEP.
Objdump: 00000000100005f0 <doit>: 100005f0: 02 10 40 3c lis r2,4098 100005f4: 00 7f 42 38 addi r2,r2,32512 100005f8: a6 02 08 7c mflr r0 100005fc: 10 00 01 f8 std r0,16(r1) 10000600: f8 ff e1 fb std r31,-8(r1)
Before applying patch: $ cat /sys/kernel/debug/tracing/uprobe_events r:probe_uprobe_test/doit /home/ravi/uprobe_test:0x00000000000005f0
After applying patch: $ cat /sys/kernel/debug/tracing/uprobe_events r:probe_uprobe_test/doit /home/ravi/uprobe_test:0x00000000000005f8
This is not the case with kretprobe because kernel itself finds LEP and probes on it.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> --- tools/perf/arch/powerpc/util/sym-handling.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/perf/arch/powerpc/util/sym-handling.c b/tools/perf/arch/powerpc/util/sym-handling.c index ed9d5d1..1030a6e 100644 --- a/tools/perf/arch/powerpc/util/sym-handling.c +++ b/tools/perf/arch/powerpc/util/sym-handling.c @@ -82,7 +82,8 @@ void arch__fix_tev_from_maps(struct perf_probe_event *pev, * * In addition, we shouldn't specify an offset for kretprobes. */ - if (pev->point.offset || pev->point.retprobe || !map || !sym) + if (pev->point.offset || (!pev->uprobes && pev->point.retprobe) || + !map || !sym) return; lep_offset = PPC64_LOCAL_ENTRY_OFFSET(sym->arch_sym); -- 2.7.4
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