Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751758AbdFAKYs (ORCPT ); Thu, 1 Jun 2017 06:24:48 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:35878 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751180AbdFAKYr (ORCPT ); Thu, 1 Jun 2017 06:24:47 -0400 From: Paolo Bonzini To: linux-kernel@vger.kernel.org Cc: acme@kernel.org, "Naveen N. Rao" , Ravi Bangoria , linuxppc-dev@lists.ozlabs.org Subject: [PATCH v2] perf: libdw support for powerpc Date: Thu, 1 Jun 2017 12:24:41 +0200 Message-Id: <1496312681-20133-1-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4313 Lines: 130 Porting PPC to libdw only needs an architecture-specific hook to move the register state from perf to libdw. The ARM and x86 architectures already use libdw, and it is useful to have as much common code for the unwinder as possible. Mark Wielaard has contributed a frame-based unwinder to libdw, so that unwinding works even for binaries that do not have CFI information. In addition, libunwind is always preferred to libdw by the build machinery so this cannot introduce regressions on machines that have both libunwind and libdw installed. Cc: acme@kernel.org Cc: Naveen N. Rao Cc: Ravi Bangoria Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Paolo Bonzini --- v1->v2: fix for 4.11->4.12 changes tools/perf/Makefile.config | 2 +- tools/perf/arch/powerpc/util/Build | 2 + tools/perf/arch/powerpc/util/unwind-libdw.c | 73 +++++++++++++++++++++++++++++ 3 files changed, 76 insertions(+), 1 deletion(-) create mode 100644 tools/perf/arch/powerpc/util/unwind-libdw.c diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 8354d04b392f..e7b04a729417 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -61,7 +61,7 @@ endif # Disable it on all other architectures in case libdw unwind # support is detected in system. Add supported architectures # to the check. -ifneq ($(ARCH),$(filter $(ARCH),x86 arm)) +ifneq ($(ARCH),$(filter $(ARCH),x86 arm powerpc)) NO_LIBDW_DWARF_UNWIND := 1 endif diff --git a/tools/perf/arch/powerpc/util/Build b/tools/perf/arch/powerpc/util/Build index 90ad64b231cd..2e6595310420 100644 --- a/tools/perf/arch/powerpc/util/Build +++ b/tools/perf/arch/powerpc/util/Build @@ -5,4 +5,6 @@ libperf-y += perf_regs.o libperf-$(CONFIG_DWARF) += dwarf-regs.o libperf-$(CONFIG_DWARF) += skip-callchain-idx.o + libperf-$(CONFIG_LIBUNWIND) += unwind-libunwind.o +libperf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o diff --git a/tools/perf/arch/powerpc/util/unwind-libdw.c b/tools/perf/arch/powerpc/util/unwind-libdw.c new file mode 100644 index 000000000000..3a24b3c43273 --- /dev/null +++ b/tools/perf/arch/powerpc/util/unwind-libdw.c @@ -0,0 +1,73 @@ +#include +#include "../../util/unwind-libdw.h" +#include "../../util/perf_regs.h" +#include "../../util/event.h" + +/* See backends/ppc_initreg.c and backends/ppc_regs.c in elfutils. */ +static const int special_regs[3][2] = { + { 65, PERF_REG_POWERPC_LINK }, + { 101, PERF_REG_POWERPC_XER }, + { 109, PERF_REG_POWERPC_CTR }, +}; + +bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg) +{ + struct unwind_info *ui = arg; + struct regs_dump *user_regs = &ui->sample->user_regs; + Dwarf_Word dwarf_regs[32], dwarf_nip; + size_t i; + +#define REG(r) ({ \ + Dwarf_Word val = 0; \ + perf_reg_value(&val, user_regs, PERF_REG_POWERPC_##r); \ + val; \ +}) + + dwarf_regs[0] = REG(R0); + dwarf_regs[1] = REG(R1); + dwarf_regs[2] = REG(R2); + dwarf_regs[3] = REG(R3); + dwarf_regs[4] = REG(R4); + dwarf_regs[5] = REG(R5); + dwarf_regs[6] = REG(R6); + dwarf_regs[7] = REG(R7); + dwarf_regs[8] = REG(R8); + dwarf_regs[9] = REG(R9); + dwarf_regs[10] = REG(R10); + dwarf_regs[11] = REG(R11); + dwarf_regs[12] = REG(R12); + dwarf_regs[13] = REG(R13); + dwarf_regs[14] = REG(R14); + dwarf_regs[15] = REG(R15); + dwarf_regs[16] = REG(R16); + dwarf_regs[17] = REG(R17); + dwarf_regs[18] = REG(R18); + dwarf_regs[19] = REG(R19); + dwarf_regs[20] = REG(R20); + dwarf_regs[21] = REG(R21); + dwarf_regs[22] = REG(R22); + dwarf_regs[23] = REG(R23); + dwarf_regs[24] = REG(R24); + dwarf_regs[25] = REG(R25); + dwarf_regs[26] = REG(R26); + dwarf_regs[27] = REG(R27); + dwarf_regs[28] = REG(R28); + dwarf_regs[29] = REG(R29); + dwarf_regs[30] = REG(R30); + dwarf_regs[31] = REG(R31); + if (!dwfl_thread_state_registers(thread, 0, 32, dwarf_regs)) + return false; + + dwarf_nip = REG(NIP); + dwfl_thread_state_register_pc(thread, dwarf_nip); + for (i = 0; i < ARRAY_SIZE(special_regs); i++) { + Dwarf_Word val = 0; + perf_reg_value(&val, user_regs, special_regs[i][1]); + if (!dwfl_thread_state_registers(thread, + special_regs[i][0], 1, + &val)) + return false; + } + + return true; +} -- 1.8.3.1