Re: [PATCH v3 2/3] perf tools: Add support for MIPS userspace DWARF callchains.

From: Arnaldo Carvalho de Melo
Date: Fri Apr 01 2016 - 10:07:15 EST


Em Fri, Apr 01, 2016 at 10:56:56AM +0200, Ralf Baechle escreveu:
> From: David Daney <david.daney@xxxxxxxxxx>
>
> Hack up the Makefile and add support code for mips unwinding
> and dwarf-regs.

Bzzt, failing to build on a minimal mips64 debian experimental env, on the one
hand you expect perf/arch/mips/util/dwarf-regs.o to be built but something,
probably some missing devel package, is not triggering its build:

# docker run -v /home/acme/git:/git --privileged=true --rm=true -t -i perf-build-minimal-debian-experimental-x-mips64
make: Entering directory '/git/linux/tools/perf'
BUILD: Doing 'make -j4' parallel build
sh: 1: command: Illegal option -c

Auto-detecting system features:
... dwarf: [ OFF ]
... glibc: [ on ]
... gtk2: [ OFF ]
... libaudit: [ OFF ]
... libbfd: [ OFF ]
... libelf: [ OFF ]
... libnuma: [ OFF ]
... numa_num_possible_cpus: [ OFF ]
... libperl: [ OFF ]
... libpython: [ OFF ]
... libslang: [ OFF ]
... libcrypto: [ OFF ]
... libunwind: [ OFF ]
... libdw-dwarf-unwind: [ OFF ]
... zlib: [ OFF ]
... lzma: [ OFF ]
... get_cpuid: [ OFF ]
... bpf: [ on ]

config/Makefile:246: No libelf found, disables 'probe' tool and BPF support in 'perf record', please install elfutils-libelf-devel/libelf-dev
config/Makefile:364: Disabling post unwind, no support found.
config/Makefile:405: No libaudit.h found, disables 'trace' tool, please install audit-libs-devel or libaudit-dev
config/Makefile:416: No libcrypto.h found, disables jitted code injection, please install libssl-devel or libssl-dev
config/Makefile:431: slang not found, disables TUI support. Please install slang-devel or libslang-dev
config/Makefile:445: GTK2 not found, disables GTK2 support. Please install gtk2-devel or libgtk2.0-dev
config/Makefile:473: Missing perl devel files. Disabling perl scripting support, please install perl-ExtUtils-Embed/libperl-dev
config/Makefile:499: No python interpreter was found: disables Python support - please install python-devel/python-dev
config/Makefile:606: No liblzma found, disables xz kernel module decompression, please install xz-devel/liblzma-dev
config/Makefile:619: No numa.h found, disables 'perf bench numa mem' benchmark, please install numactl-devel/libnuma-devel/libnuma-dev
config/Makefile:676: Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc
MKDIR /tmp/build/perf/util/
CC /tmp/build/perf/util/alias.o
MKDIR /tmp/build/perf/fd/
CC /tmp/build/perf/exec-cmd.o
CC /tmp/build/perf/event-parse.o
CC /tmp/build/perf/fd/array.o
LD /tmp/build/perf/fd/libapi-in.o
MKDIR /tmp/build/perf/fs/
CC /tmp/build/perf/fs/fs.o
MKDIR /tmp/build/perf/util/
CC /tmp/build/perf/util/annotate.o
CC /tmp/build/perf/help.o
MKDIR /tmp/build/perf/fs/
CC /tmp/build/perf/fs/tracing_path.o
CC /tmp/build/perf/pager.o
LD /tmp/build/perf/fs/libapi-in.o
CC /tmp/build/perf/cpu.o
CC /tmp/build/perf/event-plugin.o
CC /tmp/build/perf/parse-options.o
CC /tmp/build/perf/debug.o
LD /tmp/build/perf/libapi-in.o
AR /tmp/build/perf/libapi.a
CC /tmp/build/perf/trace-seq.o
CC /tmp/build/perf/parse-filter.o
CC /tmp/build/perf/parse-utils.o
CC /tmp/build/perf/kbuffer-parse.o
LD /tmp/build/perf/libtraceevent-in.o
LINK /tmp/build/perf/libtraceevent.a
GEN /tmp/build/perf/common-cmds.h
CC /tmp/build/perf/plugin_jbd2.o
LD /tmp/build/perf/plugin_jbd2-in.o
CC /tmp/build/perf/plugin_hrtimer.o
PERF_VERSION = 4.5.0
CC /tmp/build/perf/builtin-bench.o
LD /tmp/build/perf/plugin_hrtimer-in.o
CC /tmp/build/perf/plugin_kmem.o
CC /tmp/build/perf/run-command.o
LD /tmp/build/perf/plugin_kmem-in.o
CC /tmp/build/perf/plugin_kvm.o
LD /tmp/build/perf/plugin_kvm-in.o
CC /tmp/build/perf/plugin_mac80211.o
LD /tmp/build/perf/plugin_mac80211-in.o
CC /tmp/build/perf/plugin_sched_switch.o
CC /tmp/build/perf/builtin-annotate.o
CC /tmp/build/perf/sigchain.o
LD /tmp/build/perf/plugin_sched_switch-in.o
CC /tmp/build/perf/util/build-id.o
CC /tmp/build/perf/plugin_function.o
LD /tmp/build/perf/plugin_function-in.o
CC /tmp/build/perf/plugin_xen.o
CC /tmp/build/perf/subcmd-config.o
LD /tmp/build/perf/plugin_xen-in.o
CC /tmp/build/perf/plugin_scsi.o
LD /tmp/build/perf/libsubcmd-in.o
AR /tmp/build/perf/libsubcmd.a
GEN perf-archive
GEN perf-with-kcore
CC /tmp/build/perf/plugin_cfg80211.o
LD /tmp/build/perf/plugin_scsi-in.o
MKDIR /tmp/build/perf/arch/
CC /tmp/build/perf/arch/common.o
LD /tmp/build/perf/plugin_cfg80211-in.o
LINK /tmp/build/perf/plugin_jbd2.so
LINK /tmp/build/perf/plugin_hrtimer.so
LINK /tmp/build/perf/plugin_kmem.so
LINK /tmp/build/perf/plugin_kvm.so
CC /tmp/build/perf/builtin-config.o
LINK /tmp/build/perf/plugin_mac80211.so
LINK /tmp/build/perf/plugin_sched_switch.so
LINK /tmp/build/perf/plugin_function.so
LINK /tmp/build/perf/plugin_xen.so
LINK /tmp/build/perf/plugin_scsi.so
CC /tmp/build/perf/builtin-diff.o
LINK /tmp/build/perf/plugin_cfg80211.so
MKDIR /tmp/build/perf/arch/mips/util/
LD /tmp/build/perf/arch/mips/util/libperf-in.o
LD /tmp/build/perf/arch/mips/libperf-in.o
CC /tmp/build/perf/util/config.o
LD /tmp/build/perf/arch/libperf-in.o
CC /tmp/build/perf/builtin-evlist.o
GEN /tmp/build/perf/libtraceevent-dynamic-list
CC /tmp/build/perf/builtin-help.o
CC /tmp/build/perf/builtin-sched.o
MKDIR /tmp/build/perf/ui/
CC /tmp/build/perf/ui/setup.o
CC /tmp/build/perf/util/ctype.o
CC /tmp/build/perf/util/db-export.o
MKDIR /tmp/build/perf/ui/
CC /tmp/build/perf/ui/helpline.o
CC /tmp/build/perf/builtin-buildid-list.o
CC /tmp/build/perf/ui/progress.o
CC /tmp/build/perf/ui/util.o
CC /tmp/build/perf/util/env.o
CC /tmp/build/perf/builtin-buildid-cache.o
CC /tmp/build/perf/ui/hist.o
CC /tmp/build/perf/util/event.o
CC /tmp/build/perf/util/evlist.o
CC /tmp/build/perf/builtin-list.o
CC /tmp/build/perf/builtin-record.o
CC /tmp/build/perf/util/evsel.o
CC /tmp/build/perf/builtin-report.o
CC /tmp/build/perf/util/find_bit.o

CC /tmp/build/perf/util/kallsyms.o
CC /tmp/build/perf/util/levenshtein.o
CC /tmp/build/perf/util/llvm-utils.o
MKDIR /tmp/build/perf/ui/stdio/
CC /tmp/build/perf/ui/stdio/hist.o
CC /tmp/build/perf/builtin-stat.o
BISON /tmp/build/perf/util/parse-events-bison.c
CC /tmp/build/perf/util/perf_regs.o
CC /tmp/build/perf/util/path.o
CC /tmp/build/perf/util/rbtree.o
LD /tmp/build/perf/ui/libperf-in.o
MKDIR /tmp/build/perf/scripts/
LD /tmp/build/perf/scripts/libperf-in.o
CC /tmp/build/perf/builtin-timechart.o
CC /tmp/build/perf/util/libstring.o
CC /tmp/build/perf/util/bitmap.o
CC /tmp/build/perf/util/hweight.o
CC /tmp/build/perf/util/quote.o
CC /tmp/build/perf/util/strbuf.o
CC /tmp/build/perf/util/string.o
CC /tmp/build/perf/util/strlist.o
CC /tmp/build/perf/util/strfilter.o
CC /tmp/build/perf/util/top.o
CC /tmp/build/perf/builtin-top.o
CC /tmp/build/perf/util/usage.o
CC /tmp/build/perf/builtin-script.o
CC /tmp/build/perf/util/wrapper.o
CC /tmp/build/perf/util/dso.o
CC /tmp/build/perf/util/symbol.o
CC /tmp/build/perf/util/color.o
CC /tmp/build/perf/builtin-kmem.o
CC /tmp/build/perf/util/header.o
CC /tmp/build/perf/util/callchain.o
CC /tmp/build/perf/builtin-lock.o
CC /tmp/build/perf/builtin-kvm.o
CC /tmp/build/perf/builtin-inject.o
CC /tmp/build/perf/builtin-mem.o
CC /tmp/build/perf/builtin-data.o
CC /tmp/build/perf/builtin-version.o
MKDIR /tmp/build/perf/bench/
CC /tmp/build/perf/bench/sched-messaging.o
MKDIR /tmp/build/perf/tests/
CC /tmp/build/perf/tests/builtin-test.o
CC /tmp/build/perf/perf.o
CC /tmp/build/perf/util/values.o
MKDIR /tmp/build/perf/bench/
CC /tmp/build/perf/bench/sched-pipe.o
MKDIR /tmp/build/perf/tests/
CC /tmp/build/perf/tests/parse-events.o
CC /tmp/build/perf/util/debug.o
CC /tmp/build/perf/bench/mem-functions.o
CC /tmp/build/perf/bench/futex-hash.o
CC /tmp/build/perf/util/machine.o
CC /tmp/build/perf/bench/futex-wake.o
CC /tmp/build/perf/bench/futex-wake-parallel.o
CC /tmp/build/perf/bench/futex-requeue.o
CC /tmp/build/perf/bench/futex-lock-pi.o
CC /tmp/build/perf/util/map.o
LD /tmp/build/perf/bench/perf-in.o
CC /tmp/build/perf/util/pstack.o
CC /tmp/build/perf/util/session.o
CC /tmp/build/perf/tests/dso-data.o
CC /tmp/build/perf/util/ordered-events.o
CC /tmp/build/perf/util/comm.o
CC /tmp/build/perf/util/thread.o
CC /tmp/build/perf/tests/attr.o
CC /tmp/build/perf/util/thread_map.o
CC /tmp/build/perf/util/trace-event-parse.o
CC /tmp/build/perf/tests/vmlinux-kallsyms.o
CC /tmp/build/perf/tests/openat-syscall.o
CC /tmp/build/perf/util/parse-events-bison.o
BISON /tmp/build/perf/util/pmu-bison.c
CC /tmp/build/perf/util/trace-event-read.o
CC /tmp/build/perf/tests/openat-syscall-all-cpus.o
CC /tmp/build/perf/tests/openat-syscall-tp-fields.o
CC /tmp/build/perf/tests/mmap-basic.o
CC /tmp/build/perf/util/trace-event-info.o
CC /tmp/build/perf/tests/perf-record.o
CC /tmp/build/perf/tests/evsel-roundtrip-name.o
CC /tmp/build/perf/util/trace-event-scripting.o
CC /tmp/build/perf/util/trace-event.o
CC /tmp/build/perf/tests/evsel-tp-sched.o
CC /tmp/build/perf/tests/fdarray.o
CC /tmp/build/perf/util/svghelper.o
CC /tmp/build/perf/util/sort.o
CC /tmp/build/perf/tests/pmu.o
CC /tmp/build/perf/tests/hists_common.o
CC /tmp/build/perf/tests/hists_link.o
CC /tmp/build/perf/tests/hists_filter.o
CC /tmp/build/perf/tests/hists_output.o
CC /tmp/build/perf/util/hist.o
CC /tmp/build/perf/tests/hists_cumulate.o
CC /tmp/build/perf/tests/python-use.o
CC /tmp/build/perf/tests/bp_signal.o
CC /tmp/build/perf/tests/bp_signal_overflow.o
CC /tmp/build/perf/tests/task-exit.o
CC /tmp/build/perf/tests/sw-clock.o
CC /tmp/build/perf/util/util.o
CC /tmp/build/perf/tests/mmap-thread-lookup.o
CC /tmp/build/perf/tests/thread-mg-share.o
CC /tmp/build/perf/tests/switch-tracking.o
CC /tmp/build/perf/tests/keep-tracking.o
CC /tmp/build/perf/util/xyarray.o
CC /tmp/build/perf/util/cpumap.o
CC /tmp/build/perf/tests/code-reading.o
CC /tmp/build/perf/util/cgroup.o
CC /tmp/build/perf/tests/sample-parsing.o
CC /tmp/build/perf/util/target.o
CC /tmp/build/perf/util/rblist.o
CC /tmp/build/perf/util/intlist.o
CC /tmp/build/perf/tests/parse-no-sample-id-all.o
CC /tmp/build/perf/tests/kmod-path.o
CC /tmp/build/perf/util/vdso.o
CC /tmp/build/perf/util/counts.o
CC /tmp/build/perf/tests/thread-map.o
CC /tmp/build/perf/util/stat.o
CC /tmp/build/perf/util/stat-shadow.o
CC /tmp/build/perf/tests/llvm.o
CC /tmp/build/perf/tests/bpf.o
CC /tmp/build/perf/tests/topology.o
CC /tmp/build/perf/util/record.o
CC /tmp/build/perf/tests/cpumap.o
CC /tmp/build/perf/util/srcline.o
CC /tmp/build/perf/tests/stat.o
CC /tmp/build/perf/tests/event_update.o
CC /tmp/build/perf/tests/event-times.o
CC /tmp/build/perf/util/data.o
CC /tmp/build/perf/util/tsc.o
CC /tmp/build/perf/util/cloexec.o
CC /tmp/build/perf/util/thread-stack.o
CC /tmp/build/perf/util/parse-branch-options.o
CC /tmp/build/perf/util/parse-regs-options.o
CC /tmp/build/perf/tests/llvm-src-base.o
CC /tmp/build/perf/tests/llvm-src-kbuild.o
CC /tmp/build/perf/tests/llvm-src-prologue.o
CC /tmp/build/perf/util/term.o
CC /tmp/build/perf/tests/llvm-src-relocation.o
LD /tmp/build/perf/tests/perf-in.o
CC /tmp/build/perf/util/help-unknown-cmd.o
CC /tmp/build/perf/util/mem-events.o
LD /tmp/build/perf/perf-in.o
CC /tmp/build/perf/util/symbol-minimal.o
MKDIR /tmp/build/perf/util/scripting-engines/
LD /tmp/build/perf/util/scripting-engines/libperf-in.o
CC /tmp/build/perf/util/demangle-java.o
FLEX /tmp/build/perf/util/parse-events-flex.c
FLEX /tmp/build/perf/util/pmu-flex.c
CC /tmp/build/perf/util/pmu-bison.o
CC /tmp/build/perf/util/parse-events.o
CC /tmp/build/perf/util/parse-events-flex.o
CC /tmp/build/perf/util/pmu.o
CC /tmp/build/perf/util/pmu-flex.o
LD /tmp/build/perf/util/libperf-in.o
LD /tmp/build/perf/libperf-in.o
AR /tmp/build/perf/libperf.a
mips64-linux-gnuabi64-ar: /tmp/build/perf/arch/mips/util/dwarf-regs.o: No such file or directory
Makefile.perf:437: recipe for target '/tmp/build/perf/libperf.a' failed
make[1]: *** [/tmp/build/perf/libperf.a] Error 1
Makefile:108: recipe for target 'install-bin' failed
make: *** [install-bin] Error 2
make: Leaving directory '/git/linux/tools/perf'
[root@jouet ~]#

> Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
> Cc: linux-mips@xxxxxxxxxxxxxx
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> ---
> tools/perf/arch/mips/Build | 2 +-
> tools/perf/arch/mips/Makefile | 7 +++
> tools/perf/arch/mips/include/perf_regs.h | 84 ++++++++++++++++++++++++++++
> tools/perf/arch/mips/util/Build | 2 +
> tools/perf/arch/mips/util/dwarf-regs.c | 37 ++++++++++++
> tools/perf/arch/mips/util/unwind-libunwind.c | 20 +++++++
> 6 files changed, 151 insertions(+), 1 deletion(-)
> create mode 100644 tools/perf/arch/mips/Makefile
> create mode 100644 tools/perf/arch/mips/include/perf_regs.h
> create mode 100644 tools/perf/arch/mips/util/Build
> create mode 100644 tools/perf/arch/mips/util/dwarf-regs.c
> create mode 100644 tools/perf/arch/mips/util/unwind-libunwind.c
>
> diff --git a/tools/perf/arch/mips/Build b/tools/perf/arch/mips/Build
> index 1bb8bf6..54afe4a 100644
> --- a/tools/perf/arch/mips/Build
> +++ b/tools/perf/arch/mips/Build
> @@ -1 +1 @@
> -# empty
> +libperf-y += util/
> diff --git a/tools/perf/arch/mips/Makefile b/tools/perf/arch/mips/Makefile
> new file mode 100644
> index 0000000..fe9b61e
> --- /dev/null
> +++ b/tools/perf/arch/mips/Makefile
> @@ -0,0 +1,7 @@
> +ifndef NO_DWARF
> +PERF_HAVE_DWARF_REGS := 1
> +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
> +endif
> +ifndef NO_LIBUNWIND
> +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind.o
> +endif
> diff --git a/tools/perf/arch/mips/include/perf_regs.h b/tools/perf/arch/mips/include/perf_regs.h
> new file mode 100644
> index 0000000..a91b904
> --- /dev/null
> +++ b/tools/perf/arch/mips/include/perf_regs.h
> @@ -0,0 +1,84 @@
> +#ifndef ARCH_PERF_REGS_H
> +#define ARCH_PERF_REGS_H
> +
> +#include <stdlib.h>
> +#include "../../util/types.h"
> +#include <asm/perf_regs.h>
> +
> +#define PERF_REG_IP PERF_REG_MIPS_PC
> +#define PERF_REG_SP PERF_REG_MIPS_R29
> +
> +#define PERF_REGS_MASK ((1ULL << PERF_REG_MIPS_MAX) - 1)
> +
> +static inline const char *perf_reg_name(int id)
> +{
> + switch (id) {
> + case PERF_REG_MIPS_PC:
> + return "PC";
> + case PERF_REG_MIPS_R1:
> + return "$1";
> + case PERF_REG_MIPS_R2:
> + return "$2";
> + case PERF_REG_MIPS_R3:
> + return "$3";
> + case PERF_REG_MIPS_R4:
> + return "$4";
> + case PERF_REG_MIPS_R5:
> + return "$5";
> + case PERF_REG_MIPS_R6:
> + return "$6";
> + case PERF_REG_MIPS_R7:
> + return "$7";
> + case PERF_REG_MIPS_R8:
> + return "$8";
> + case PERF_REG_MIPS_R9:
> + return "$9";
> + case PERF_REG_MIPS_R10:
> + return "$10";
> + case PERF_REG_MIPS_R11:
> + return "$11";
> + case PERF_REG_MIPS_R12:
> + return "$12";
> + case PERF_REG_MIPS_R13:
> + return "$13";
> + case PERF_REG_MIPS_R14:
> + return "$14";
> + case PERF_REG_MIPS_R15:
> + return "$15";
> + case PERF_REG_MIPS_R16:
> + return "$16";
> + case PERF_REG_MIPS_R17:
> + return "$17";
> + case PERF_REG_MIPS_R18:
> + return "$18";
> + case PERF_REG_MIPS_R19:
> + return "$19";
> + case PERF_REG_MIPS_R20:
> + return "$20";
> + case PERF_REG_MIPS_R21:
> + return "$21";
> + case PERF_REG_MIPS_R22:
> + return "$22";
> + case PERF_REG_MIPS_R23:
> + return "$23";
> + case PERF_REG_MIPS_R24:
> + return "$24";
> + case PERF_REG_MIPS_R25:
> + return "$25";
> +
> + case PERF_REG_MIPS_R28:
> + return "$28";
> + case PERF_REG_MIPS_R29:
> + return "$29";
> + case PERF_REG_MIPS_R30:
> + return "$30";
> + case PERF_REG_MIPS_R31:
> + return "$31";
> + default:
> + break;
> + }
> + return NULL;
> +}
> +
> +
> +#endif /* ARCH_PERF_REGS_H */
> diff --git a/tools/perf/arch/mips/util/Build b/tools/perf/arch/mips/util/Build
> new file mode 100644
> index 0000000..baeccb0
> --- /dev/null
> +++ b/tools/perf/arch/mips/util/Build
> @@ -0,0 +1,2 @@
> +libperf-$(CONFIG_DWARF) += dwarf-regs.o
> +libperf-$(CONFIG_LIBUNWIND) += unwind-libunwind.o
> diff --git a/tools/perf/arch/mips/util/dwarf-regs.c b/tools/perf/arch/mips/util/dwarf-regs.c
> new file mode 100644
> index 0000000..165e017
> --- /dev/null
> +++ b/tools/perf/arch/mips/util/dwarf-regs.c
> @@ -0,0 +1,37 @@
> +/*
> + * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
> + *
> + * Copyright (C) 2013 Cavium, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +
> +#include <libio.h>
> +#include <dwarf-regs.h>
> +
> +static const char *mips_gpr_names[32] = {
> + "$0", "$1", "$2", "$3", "$4", "$5", "$6", "$7", "$8", "$9",
> + "$10", "$11", "$12", "$13", "$14", "$15", "$16", "$17", "$18", "$19",
> + "$20", "$21", "$22", "$23", "$24", "$25", "$26", "$27", "$28", "$29",
> + "$30", "$31"
> +};
> +
> +const char *get_arch_regstr(unsigned int n)
> +{
> + if (n < 32)
> + return mips_gpr_names[n];
> + if (n == 64)
> + return "hi";
> + if (n == 65)
> + return "lo";
> + return NULL;
> +}
> diff --git a/tools/perf/arch/mips/util/unwind-libunwind.c b/tools/perf/arch/mips/util/unwind-libunwind.c
> new file mode 100644
> index 0000000..612949b
> --- /dev/null
> +++ b/tools/perf/arch/mips/util/unwind-libunwind.c
> @@ -0,0 +1,20 @@
> +
> +#include <errno.h>
> +#include <libunwind.h>
> +#include "perf_regs.h"
> +#include "../../util/unwind.h"
> +
> +int unwind__arch_reg_id(int regnum)
> +{
> + switch (regnum) {
> + case UNW_MIPS_R1 ... UNW_MIPS_R25:
> + return regnum - UNW_MIPS_R1 + PERF_REG_MIPS_R1;
> + case UNW_MIPS_R28 ... UNW_MIPS_R31:
> + return regnum - UNW_MIPS_R28 + PERF_REG_MIPS_R28;
> + case UNW_MIPS_PC:
> + return PERF_REG_MIPS_PC;
> + default:
> + pr_err("unwind: invalid reg id %d\n", regnum);
> + return -EINVAL;
> + }
> +}
> --
> 2.5.5
>