[PATCH v3 1/3] perf/sdt/x86: Add renaming logic for (missing) 8 bit registers

From: Ravi Bangoria
Date: Tue Mar 28 2017 - 09:51:26 EST


I found couple of events using al, bl, cl and dl registers for
argument. These are not directly accepted by uprobe_events and
thus needs to be mapped to ax, bx, cx and dx respectively.

Few ex,

/usr/bin/qemu-system-s390x
css_adapter_interrupt: 1@%bl
css_chpid_add: 1@%cl 1@%sil 1@%dl
dma_bdrv_io: 8@%rbx 8@%rbp -8@%r14 1@%al

/usr/bin/postgres
buffer__read__done: ... -1@-bash -1@%al
buffer__read__start: ... -1@%al

I don't find any sdt events using ah, bh,... registers. But I
also don't see any reason to not use them, so there might be
rare events using these registers, and if so, perf should have
a renaming logic for them too.

Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxxxxxxx>
---
tools/perf/arch/x86/util/perf_regs.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/tools/perf/arch/x86/util/perf_regs.c b/tools/perf/arch/x86/util/perf_regs.c
index d8a8dcf..fa1fd19 100644
--- a/tools/perf/arch/x86/util/perf_regs.c
+++ b/tools/perf/arch/x86/util/perf_regs.c
@@ -40,12 +40,20 @@ struct sdt_name_reg {
static const struct sdt_name_reg sdt_reg_renamings[] = {
SDT_NAME_REG(eax, ax),
SDT_NAME_REG(rax, ax),
+ SDT_NAME_REG(al, ax),
+ SDT_NAME_REG(ah, ax),
SDT_NAME_REG(ebx, bx),
SDT_NAME_REG(rbx, bx),
+ SDT_NAME_REG(bl, bx),
+ SDT_NAME_REG(bh, bx),
SDT_NAME_REG(ecx, cx),
SDT_NAME_REG(rcx, cx),
+ SDT_NAME_REG(cl, cx),
+ SDT_NAME_REG(ch, cx),
SDT_NAME_REG(edx, dx),
SDT_NAME_REG(rdx, dx),
+ SDT_NAME_REG(dl, dx),
+ SDT_NAME_REG(dh, dx),
SDT_NAME_REG(esi, si),
SDT_NAME_REG(rsi, si),
SDT_NAME_REG(sil, si),
--
2.9.3