summaryrefslogtreecommitdiff
path: root/tools/perf/arch/powerpc
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /tools/perf/arch/powerpc
Initial import
Diffstat (limited to 'tools/perf/arch/powerpc')
-rw-r--r--tools/perf/arch/powerpc/Build1
-rw-r--r--tools/perf/arch/powerpc/Makefile3
-rw-r--r--tools/perf/arch/powerpc/util/Build4
-rw-r--r--tools/perf/arch/powerpc/util/dwarf-regs.c88
-rw-r--r--tools/perf/arch/powerpc/util/header.c34
-rw-r--r--tools/perf/arch/powerpc/util/skip-callchain-idx.c280
6 files changed, 410 insertions, 0 deletions
diff --git a/tools/perf/arch/powerpc/Build b/tools/perf/arch/powerpc/Build
new file mode 100644
index 000000000..54afe4a46
--- /dev/null
+++ b/tools/perf/arch/powerpc/Build
@@ -0,0 +1 @@
+libperf-y += util/
diff --git a/tools/perf/arch/powerpc/Makefile b/tools/perf/arch/powerpc/Makefile
new file mode 100644
index 000000000..7fbca1750
--- /dev/null
+++ b/tools/perf/arch/powerpc/Makefile
@@ -0,0 +1,3 @@
+ifndef NO_DWARF
+PERF_HAVE_DWARF_REGS := 1
+endif
diff --git a/tools/perf/arch/powerpc/util/Build b/tools/perf/arch/powerpc/util/Build
new file mode 100644
index 000000000..0af6e9b3f
--- /dev/null
+++ b/tools/perf/arch/powerpc/util/Build
@@ -0,0 +1,4 @@
+libperf-y += header.o
+
+libperf-$(CONFIG_DWARF) += dwarf-regs.o
+libperf-$(CONFIG_DWARF) += skip-callchain-idx.o
diff --git a/tools/perf/arch/powerpc/util/dwarf-regs.c b/tools/perf/arch/powerpc/util/dwarf-regs.c
new file mode 100644
index 000000000..733151cdf
--- /dev/null
+++ b/tools/perf/arch/powerpc/util/dwarf-regs.c
@@ -0,0 +1,88 @@
+/*
+ * Mapping of DWARF debug register numbers into register names.
+ *
+ * Copyright (C) 2010 Ian Munsie, IBM Corporation.
+ *
+ * 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.
+ */
+
+#include <stddef.h>
+#include <dwarf-regs.h>
+
+
+struct pt_regs_dwarfnum {
+ const char *name;
+ unsigned int dwarfnum;
+};
+
+#define STR(s) #s
+#define REG_DWARFNUM_NAME(r, num) {.name = r, .dwarfnum = num}
+#define GPR_DWARFNUM_NAME(num) \
+ {.name = STR(%gpr##num), .dwarfnum = num}
+#define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0}
+
+/*
+ * Reference:
+ * http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
+ */
+static const struct pt_regs_dwarfnum regdwarfnum_table[] = {
+ GPR_DWARFNUM_NAME(0),
+ GPR_DWARFNUM_NAME(1),
+ GPR_DWARFNUM_NAME(2),
+ GPR_DWARFNUM_NAME(3),
+ GPR_DWARFNUM_NAME(4),
+ GPR_DWARFNUM_NAME(5),
+ GPR_DWARFNUM_NAME(6),
+ GPR_DWARFNUM_NAME(7),
+ GPR_DWARFNUM_NAME(8),
+ GPR_DWARFNUM_NAME(9),
+ GPR_DWARFNUM_NAME(10),
+ GPR_DWARFNUM_NAME(11),
+ GPR_DWARFNUM_NAME(12),
+ GPR_DWARFNUM_NAME(13),
+ GPR_DWARFNUM_NAME(14),
+ GPR_DWARFNUM_NAME(15),
+ GPR_DWARFNUM_NAME(16),
+ GPR_DWARFNUM_NAME(17),
+ GPR_DWARFNUM_NAME(18),
+ GPR_DWARFNUM_NAME(19),
+ GPR_DWARFNUM_NAME(20),
+ GPR_DWARFNUM_NAME(21),
+ GPR_DWARFNUM_NAME(22),
+ GPR_DWARFNUM_NAME(23),
+ GPR_DWARFNUM_NAME(24),
+ GPR_DWARFNUM_NAME(25),
+ GPR_DWARFNUM_NAME(26),
+ GPR_DWARFNUM_NAME(27),
+ GPR_DWARFNUM_NAME(28),
+ GPR_DWARFNUM_NAME(29),
+ GPR_DWARFNUM_NAME(30),
+ GPR_DWARFNUM_NAME(31),
+ REG_DWARFNUM_NAME("%msr", 66),
+ REG_DWARFNUM_NAME("%ctr", 109),
+ REG_DWARFNUM_NAME("%link", 108),
+ REG_DWARFNUM_NAME("%xer", 101),
+ REG_DWARFNUM_NAME("%dar", 119),
+ REG_DWARFNUM_NAME("%dsisr", 118),
+ REG_DWARFNUM_END,
+};
+
+/**
+ * get_arch_regstr() - lookup register name from it's DWARF register number
+ * @n: the DWARF register number
+ *
+ * get_arch_regstr() returns the name of the register in struct
+ * regdwarfnum_table from it's DWARF register number. If the register is not
+ * found in the table, this returns NULL;
+ */
+const char *get_arch_regstr(unsigned int n)
+{
+ const struct pt_regs_dwarfnum *roff;
+ for (roff = regdwarfnum_table; roff->name != NULL; roff++)
+ if (roff->dwarfnum == n)
+ return roff->name;
+ return NULL;
+}
diff --git a/tools/perf/arch/powerpc/util/header.c b/tools/perf/arch/powerpc/util/header.c
new file mode 100644
index 000000000..6c1b8a75d
--- /dev/null
+++ b/tools/perf/arch/powerpc/util/header.c
@@ -0,0 +1,34 @@
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "../../util/header.h"
+#include "../../util/util.h"
+
+#define mfspr(rn) ({unsigned long rval; \
+ asm volatile("mfspr %0," __stringify(rn) \
+ : "=r" (rval)); rval; })
+
+#define SPRN_PVR 0x11F /* Processor Version Register */
+#define PVR_VER(pvr) (((pvr) >> 16) & 0xFFFF) /* Version field */
+#define PVR_REV(pvr) (((pvr) >> 0) & 0xFFFF) /* Revison field */
+
+int
+get_cpuid(char *buffer, size_t sz)
+{
+ unsigned long pvr;
+ int nb;
+
+ pvr = mfspr(SPRN_PVR);
+
+ nb = scnprintf(buffer, sz, "%lu,%lu$", PVR_VER(pvr), PVR_REV(pvr));
+
+ /* look for end marker to ensure the entire data fit */
+ if (strchr(buffer, '$')) {
+ buffer[nb-1] = '\0';
+ return 0;
+ }
+ return -1;
+}
diff --git a/tools/perf/arch/powerpc/util/skip-callchain-idx.c b/tools/perf/arch/powerpc/util/skip-callchain-idx.c
new file mode 100644
index 000000000..0c370f81e
--- /dev/null
+++ b/tools/perf/arch/powerpc/util/skip-callchain-idx.c
@@ -0,0 +1,280 @@
+/*
+ * Use DWARF Debug information to skip unnecessary callchain entries.
+ *
+ * Copyright (C) 2014 Sukadev Bhattiprolu, IBM Corporation.
+ * Copyright (C) 2014 Ulrich Weigand, IBM Corporation.
+ *
+ * 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.
+ */
+#include <inttypes.h>
+#include <dwarf.h>
+#include <elfutils/libdwfl.h>
+
+#include "util/thread.h"
+#include "util/callchain.h"
+#include "util/debug.h"
+
+/*
+ * When saving the callchain on Power, the kernel conservatively saves
+ * excess entries in the callchain. A few of these entries are needed
+ * in some cases but not others. If the unnecessary entries are not
+ * ignored, we end up with duplicate arcs in the call-graphs. Use
+ * DWARF debug information to skip over any unnecessary callchain
+ * entries.
+ *
+ * See function header for arch_adjust_callchain() below for more details.
+ *
+ * The libdwfl code in this file is based on code from elfutils
+ * (libdwfl/argp-std.c, libdwfl/tests/addrcfi.c, etc).
+ */
+static char *debuginfo_path;
+
+static const Dwfl_Callbacks offline_callbacks = {
+ .debuginfo_path = &debuginfo_path,
+ .find_debuginfo = dwfl_standard_find_debuginfo,
+ .section_address = dwfl_offline_section_address,
+};
+
+
+/*
+ * Use the DWARF expression for the Call-frame-address and determine
+ * if return address is in LR and if a new frame was allocated.
+ */
+static int check_return_reg(int ra_regno, Dwarf_Frame *frame)
+{
+ Dwarf_Op ops_mem[2];
+ Dwarf_Op dummy;
+ Dwarf_Op *ops = &dummy;
+ size_t nops;
+ int result;
+
+ result = dwarf_frame_register(frame, ra_regno, ops_mem, &ops, &nops);
+ if (result < 0) {
+ pr_debug("dwarf_frame_register() %s\n", dwarf_errmsg(-1));
+ return -1;
+ }
+
+ /*
+ * Check if return address is on the stack.
+ */
+ if (nops != 0 || ops != NULL)
+ return 0;
+
+ /*
+ * Return address is in LR. Check if a frame was allocated
+ * but not-yet used.
+ */
+ result = dwarf_frame_cfa(frame, &ops, &nops);
+ if (result < 0) {
+ pr_debug("dwarf_frame_cfa() returns %d, %s\n", result,
+ dwarf_errmsg(-1));
+ return -1;
+ }
+
+ /*
+ * If call frame address is in r1, no new frame was allocated.
+ */
+ if (nops == 1 && ops[0].atom == DW_OP_bregx && ops[0].number == 1 &&
+ ops[0].number2 == 0)
+ return 1;
+
+ /*
+ * A new frame was allocated but has not yet been used.
+ */
+ return 2;
+}
+
+/*
+ * Get the DWARF frame from the .eh_frame section.
+ */
+static Dwarf_Frame *get_eh_frame(Dwfl_Module *mod, Dwarf_Addr pc)
+{
+ int result;
+ Dwarf_Addr bias;
+ Dwarf_CFI *cfi;
+ Dwarf_Frame *frame;
+
+ cfi = dwfl_module_eh_cfi(mod, &bias);
+ if (!cfi) {
+ pr_debug("%s(): no CFI - %s\n", __func__, dwfl_errmsg(-1));
+ return NULL;
+ }
+
+ result = dwarf_cfi_addrframe(cfi, pc-bias, &frame);
+ if (result) {
+ pr_debug("%s(): %s\n", __func__, dwfl_errmsg(-1));
+ return NULL;
+ }
+
+ return frame;
+}
+
+/*
+ * Get the DWARF frame from the .debug_frame section.
+ */
+static Dwarf_Frame *get_dwarf_frame(Dwfl_Module *mod, Dwarf_Addr pc)
+{
+ Dwarf_CFI *cfi;
+ Dwarf_Addr bias;
+ Dwarf_Frame *frame;
+ int result;
+
+ cfi = dwfl_module_dwarf_cfi(mod, &bias);
+ if (!cfi) {
+ pr_debug("%s(): no CFI - %s\n", __func__, dwfl_errmsg(-1));
+ return NULL;
+ }
+
+ result = dwarf_cfi_addrframe(cfi, pc-bias, &frame);
+ if (result) {
+ pr_debug("%s(): %s\n", __func__, dwfl_errmsg(-1));
+ return NULL;
+ }
+
+ return frame;
+}
+
+/*
+ * Return:
+ * 0 if return address for the program counter @pc is on stack
+ * 1 if return address is in LR and no new stack frame was allocated
+ * 2 if return address is in LR and a new frame was allocated (but not
+ * yet used)
+ * -1 in case of errors
+ */
+static int check_return_addr(struct dso *dso, u64 map_start, Dwarf_Addr pc)
+{
+ int rc = -1;
+ Dwfl *dwfl;
+ Dwfl_Module *mod;
+ Dwarf_Frame *frame;
+ int ra_regno;
+ Dwarf_Addr start = pc;
+ Dwarf_Addr end = pc;
+ bool signalp;
+ const char *exec_file = dso->long_name;
+
+ dwfl = dso->dwfl;
+
+ if (!dwfl) {
+ dwfl = dwfl_begin(&offline_callbacks);
+ if (!dwfl) {
+ pr_debug("dwfl_begin() failed: %s\n", dwarf_errmsg(-1));
+ return -1;
+ }
+
+ mod = dwfl_report_elf(dwfl, exec_file, exec_file, -1,
+ map_start, false);
+ if (!mod) {
+ pr_debug("dwfl_report_elf() failed %s\n",
+ dwarf_errmsg(-1));
+ /*
+ * We normally cache the DWARF debug info and never
+ * call dwfl_end(). But to prevent fd leak, free in
+ * case of error.
+ */
+ dwfl_end(dwfl);
+ goto out;
+ }
+ dso->dwfl = dwfl;
+ }
+
+ mod = dwfl_addrmodule(dwfl, pc);
+ if (!mod) {
+ pr_debug("dwfl_addrmodule() failed, %s\n", dwarf_errmsg(-1));
+ goto out;
+ }
+
+ /*
+ * To work with split debug info files (eg: glibc), check both
+ * .eh_frame and .debug_frame sections of the ELF header.
+ */
+ frame = get_eh_frame(mod, pc);
+ if (!frame) {
+ frame = get_dwarf_frame(mod, pc);
+ if (!frame)
+ goto out;
+ }
+
+ ra_regno = dwarf_frame_info(frame, &start, &end, &signalp);
+ if (ra_regno < 0) {
+ pr_debug("Return address register unavailable: %s\n",
+ dwarf_errmsg(-1));
+ goto out;
+ }
+
+ rc = check_return_reg(ra_regno, frame);
+
+out:
+ return rc;
+}
+
+/*
+ * The callchain saved by the kernel always includes the link register (LR).
+ *
+ * 0: PERF_CONTEXT_USER
+ * 1: Program counter (Next instruction pointer)
+ * 2: LR value
+ * 3: Caller's caller
+ * 4: ...
+ *
+ * The value in LR is only needed when it holds a return address. If the
+ * return address is on the stack, we should ignore the LR value.
+ *
+ * Further, when the return address is in the LR, if a new frame was just
+ * allocated but the LR was not saved into it, then the LR contains the
+ * caller, slot 4: contains the caller's caller and the contents of slot 3:
+ * (chain->ips[3]) is undefined and must be ignored.
+ *
+ * Use DWARF debug information to determine if any entries need to be skipped.
+ *
+ * Return:
+ * index: of callchain entry that needs to be ignored (if any)
+ * -1 if no entry needs to be ignored or in case of errors
+ */
+int arch_skip_callchain_idx(struct thread *thread, struct ip_callchain *chain)
+{
+ struct addr_location al;
+ struct dso *dso = NULL;
+ int rc;
+ u64 ip;
+ u64 skip_slot = -1;
+
+ if (chain->nr < 3)
+ return skip_slot;
+
+ ip = chain->ips[2];
+
+ thread__find_addr_location(thread, PERF_RECORD_MISC_USER,
+ MAP__FUNCTION, ip, &al);
+
+ if (al.map)
+ dso = al.map->dso;
+
+ if (!dso) {
+ pr_debug("%" PRIx64 " dso is NULL\n", ip);
+ return skip_slot;
+ }
+
+ rc = check_return_addr(dso, al.map->start, ip);
+
+ pr_debug("[DSO %s, sym %s, ip 0x%" PRIx64 "] rc %d\n",
+ dso->long_name, al.sym->name, ip, rc);
+
+ if (rc == 0) {
+ /*
+ * Return address on stack. Ignore LR value in callchain
+ */
+ skip_slot = 2;
+ } else if (rc == 2) {
+ /*
+ * New frame allocated but return address still in LR.
+ * Ignore the caller's caller entry in callchain.
+ */
+ skip_slot = 3;
+ }
+ return skip_slot;
+}