diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/Documentation/perf-probe.txt | 48 | ||||
| -rw-r--r-- | tools/perf/Makefile | 11 | ||||
| -rw-r--r-- | tools/perf/builtin-probe.c | 372 | ||||
| -rw-r--r-- | tools/perf/builtin.h | 1 | ||||
| -rw-r--r-- | tools/perf/command-list.txt | 1 | ||||
| -rw-r--r-- | tools/perf/perf.c | 1 | ||||
| -rw-r--r-- | tools/perf/util/probe-finder.c | 677 | ||||
| -rw-r--r-- | tools/perf/util/probe-finder.h | 53 | ||||
| -rw-r--r-- | tools/perf/util/util.h | 9 |
9 files changed, 1173 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt new file mode 100644 index 00000000000..6b6c6aecdf1 --- /dev/null +++ b/tools/perf/Documentation/perf-probe.txt @@ -0,0 +1,48 @@ +perf-probe(1) +============= + +NAME +---- +perf-probe - Define new dynamic tracepoints + +SYNOPSIS +-------- +[verse] +'perf probe' [-k <file>] -P 'PROBE' [-P 'PROBE' ...] + + +DESCRIPTION +----------- +This command defines dynamic tracepoint events, by symbol and registers +without debuginfo, or by C expressions (C line numbers, C function names, +and C local variables) with debuginfo. + + +OPTIONS +------- +-k:: +--vmlinux:: + Specify vmlinux path which has debuginfo (Dwarf binary). + +-v:: +--verbose:: + Be more verbose (show parsed arguments, etc). + +-P:: +--probe:: + Define a probe point (see PROBE SYNTAX for detail) + +PROBE SYNTAX +------------ +Probe points are defined by following syntax. + + "TYPE:[GRP/]NAME FUNC[+OFFS][@SRC]|@SRC:LINE [ARG ...]" + +'TYPE' specifies the type of probe point, you can use either "p" (kprobe) or "r" (kretprobe) for 'TYPE'. 'GRP' specifies the group name of this probe, and 'NAME' specifies the event name. If 'GRP' is omitted, "kprobes" is used for its group name. +'FUNC' and 'OFFS' specifies function and offset (in byte) where probe will be put. In addition, 'SRC' specifies a source file which has that function (this is mainly for inline functions). +You can specify a probe point by the source line number by using '@SRC:LINE' syntax, where 'SRC' is the source file path and 'LINE' is the line number. +'ARG' specifies the arguments of this probe point. You can use the name of local variable, or kprobe-tracer argument format (e.g. $retval, %ax, etc). + +SEE ALSO +-------- +linkperf:perf-trace[1], linkperf:perf-record[1] diff --git a/tools/perf/Makefile b/tools/perf/Makefile index 0a40c29b238..147e3cf035d 100644 --- a/tools/perf/Makefile +++ b/tools/perf/Makefile @@ -335,6 +335,7 @@ LIB_FILE=libperf.a LIB_H += ../../include/linux/perf_event.h LIB_H += ../../include/linux/rbtree.h LIB_H += ../../include/linux/list.h +LIB_H += ../../include/linux/stringify.h LIB_H += util/include/linux/bitmap.h LIB_H += util/include/linux/bitops.h LIB_H += util/include/linux/compiler.h @@ -425,6 +426,7 @@ BUILTIN_OBJS += builtin-stat.o BUILTIN_OBJS += builtin-timechart.o BUILTIN_OBJS += builtin-top.o BUILTIN_OBJS += builtin-trace.o +BUILTIN_OBJS += builtin-probe.o PERFLIBS = $(LIB_FILE) @@ -463,6 +465,15 @@ ifneq ($(shell sh -c "(echo '\#include <libelf.h>'; echo 'int main(void) { Elf * msg := $(error No libelf.h/libelf found, please install libelf-dev/elfutils-libelf-devel); endif +ifneq ($(shell sh -c "(echo '\#include <libdwarf/dwarf.h>'; echo '\#include <libdwarf/libdwarf.h>'; echo 'int main(void) { Dwarf_Debug dbg; Dwarf_Error err; Dwarf_Ranges *rng; dwarf_init(0, DW_DLC_READ, 0, 0, &dbg, &err); dwarf_get_ranges(dbg, 0, &rng, 0, 0, &err); return (long)dbg; }') | $(CC) -x c - $(ALL_CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -ldwarf -lelf -o /dev/null $(ALL_LDFLAGS) > /dev/null 2>&1 && echo y"), y) + msg := $(warning No libdwarf.h found or old libdwarf.h found, disables dwarf support. Please install libdwarf-dev/libdwarf-devel >= 20081231); + BASIC_CFLAGS += -DNO_LIBDWARF +else + EXTLIBS += -lelf -ldwarf + LIB_H += util/probe-finder.h + LIB_OBJS += util/probe-finder.o +endif + ifdef NO_DEMANGLE BASIC_CFLAGS += -DNO_DEMANGLE else diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c new file mode 100644 index 00000000000..b5ad86a265f --- /dev/null +++ b/tools/perf/builtin-probe.c @@ -0,0 +1,372 @@ +/* + * builtin-probe.c + * + * Builtin probe command: Set up probe events by C expression + * + * Written by Masami Hiramatsu <mhiramat@redhat.com> + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + */ +#define _GNU_SOURCE +#include <sys/utsname.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <errno.h> +#include <stdio.h> +#include <unistd.h> +#include <stdlib.h> +#include <string.h> + +#undef _GNU_SOURCE +#include "perf.h" +#include "builtin.h" +#include "util/util.h" +#include "util/event.h" +#include "util/debug.h" +#include "util/parse-options.h" +#include "util/parse-events.h" /* For debugfs_path */ +#include "util/probe-finder.h" + +/* Default vmlinux search paths */ +#define NR_SEARCH_PATH 3 +const char *default_search_path[NR_SEARCH_PATH] = { +"/lib/modules/%s/build/vmlinux", /* Custom build kernel */ +"/usr/lib/debug/lib/modules/%s/vmlinux", /* Red Hat debuginfo */ +"/boot/vmlinux-debug-%s", /* Ubuntu */ +}; + +#define MAX_PATH_LEN 256 +#define MAX_PROBES 128 +#define MAX_PROBE_ARGS 128 + +/* Session management structure */ +static struct { + char *vmlinux; + char *release; + int need_dwarf; + int nr_probe; + struct probe_point probes[MAX_PROBES]; + char *events[MAX_PROBES]; +} session; + +#define semantic_error(msg ...) die("Semantic error :" msg) + +static int parse_probepoint(const struct option *opt __used, + const char *str, int unset __used) +{ + char *argv[MAX_PROBE_ARGS + 2]; /* Event + probe + args */ + int argc, i; + char *arg, *ptr; + struct probe_point *pp = &session.probes[session.nr_probe]; + char **event = &session.events[session.nr_probe]; + int retp = 0; + + if (!str) /* The end of probe points */ + return 0; + + eprintf("probe-definition(%d): %s\n", session.nr_probe, str); + if (++session.nr_probe == MAX_PROBES) + semantic_error("Too many probes"); + + /* Separate arguments, similar to argv_split */ + argc = 0; + do { + /* Skip separators */ + while (isspace(*str)) + str++; + + /* Add an argument */ + if (*str != '\0') { + const char *s = str; + + /* Skip the argument */ + while (!isspace(*str) && *str != '\0') + str++; + + /* Duplicate the argument */ + argv[argc] = strndup(s, str - s); + if (argv[argc] == NULL) + die("strndup"); + if (++argc == MAX_PROBE_ARGS) + semantic_error("Too many arguments"); + eprintf("argv[%d]=%s\n", argc, argv[argc - 1]); + } + } while (*str != '\0'); + if (argc < 2) + semantic_error("Need event-name and probe-point at least."); + + /* Parse the event name */ + if (argv[0][0] == 'r') + retp = 1; + else if (argv[0][0] != 'p') + semantic_error("You must specify 'p'(kprobe) or" + " 'r'(kretprobe) first."); + /* TODO: check event name */ + *event = argv[0]; + + /* Parse probe point */ + arg = argv[1]; + if (arg[0] == '@') { + /* Source Line */ + arg++; + ptr = strchr(arg, ':'); + if (!ptr || !isdigit(ptr[1])) + semantic_error("Line number is required."); + *ptr++ = '\0'; + if (strlen(arg) == 0) + semantic_error("No file name."); + pp->file = strdup(arg); + pp->line = atoi(ptr); + if (!pp->file || !pp->line) + semantic_error("Failed to parse line."); + eprintf("file:%s line:%d\n", pp->file, pp->line); + } else { + /* Function name */ + ptr = strchr(arg, '+'); + if (ptr) { + if (!isdigit(ptr[1])) + semantic_error("Offset is required."); + *ptr++ = '\0'; + pp->offset = atoi(ptr); + } else + ptr = arg; + ptr = strchr(ptr, '@'); + if (ptr) { + *ptr++ = '\0'; + pp->file = strdup(ptr); + } + pp->function = strdup(arg); + eprintf("symbol:%s file:%s offset:%d\n", + pp->function, pp->file, pp->offset); + } + free(argv[1]); + if (pp->file) + session.need_dwarf = 1; + + /* Copy arguments */ + pp->nr_args = argc - 2; + if (pp->nr_args > 0) { + pp->args = (char **)malloc(sizeof(char *) * pp->nr_args); + if (!pp->args) + die("malloc"); + memcpy(pp->args, &argv[2], sizeof(char *) * pp->nr_args); + } + + /* Ensure return probe has no C argument */ + for (i = 0; i < pp->nr_args; i++) + if (is_c_varname(pp->args[i])) { + if (retp) + semantic_error("You can't specify local" + " variable for kretprobe"); + session.need_dwarf = 1; + } + + eprintf("%d arguments\n", pp->nr_args); + return 0; +} + +#ifndef NO_LIBDWARF +static int open_default_vmlinux(void) +{ + struct utsname uts; + char fname[MAX_PATH_LEN]; + int fd, ret, i; + + ret = uname(&uts); + if (ret) { + eprintf("uname() failed.\n"); + return -errno; + } + session.release = uts.release; + for (i = 0; i < NR_SEARCH_PATH; i++) { + ret = snprintf(fname, MAX_PATH_LEN, + default_search_path[i], session.release); + if (ret >= MAX_PATH_LEN || ret < 0) { + eprintf("Filename(%d,%s) is too long.\n", i, + uts.release); + errno = E2BIG; + return -E2BIG; + } + eprintf("try to open %s\n", fname); + fd = open(fname, O_RDONLY); + if (fd >= 0) + break; + } + return fd; +} +#endif + +static const char * const probe_usage[] = { + "perf probe [<options>] -P 'PROBEDEF' [-P 'PROBEDEF' ...]", + NULL +}; + +static const struct option options[] = { + OPT_BOOLEAN('v', "verbose", &verbose, + "be more verbose (show parsed arguments, etc)"), +#ifndef NO_LIBDWARF + OPT_STRING('k', "vmlinux", &session.vmlinux, "file", + "vmlinux/module pathname"), +#endif + OPT_CALLBACK('P', "probe", NULL, +#ifdef NO_LIBDWARF + "p|r:[GRP/]NAME FUNC[+OFFS] [ARG ...]", +#else + "p|r:[GRP/]NAME FUNC[+OFFS][@SRC]|@SRC:LINE [ARG ...]", +#endif + "probe point definition, where\n" + "\t\tp:\tkprobe probe\n" + "\t\tr:\tkretprobe probe\n" + "\t\tGRP:\tGroup name (optional)\n" + "\t\tNAME:\tEvent name\n" + "\t\tFUNC:\tFunction name\n" + "\t\tOFFS:\tOffset from function entry (in byte)\n" +#ifdef NO_LIBDWARF + "\t\tARG:\tProbe argument (only \n" +#else + "\t\tSRC:\tSource code path\n" + "\t\tLINE:\tLine number\n" + "\t\tARG:\tProbe argument (local variable name or\n" +#endif + "\t\t\tkprobe-tracer argument format is supported.)\n", + parse_probepoint), + OPT_END() +}; + +static int write_new_event(int fd, const char *buf) +{ + int ret; + + printf("Adding new event: %s\n", buf); + ret = write(fd, buf, strlen(buf)); + if (ret <= 0) + die("failed to create event."); + + return ret; +} + +#define MAX_CMDLEN 256 + +static int synthesize_probepoint(struct probe_point *pp) +{ + char *buf; + int i, len, ret; + pp->probes[0] = buf = (char *)calloc(MAX_CMDLEN, sizeof(char)); + if (!buf) + die("calloc"); + ret = snprintf(buf, MAX_CMDLEN, "%s+%d", pp->function, pp->offset); + if (ret <= 0 || ret >= MAX_CMDLEN) + goto error; + len = ret; + + for (i = 0; i < pp->nr_args; i++) { + ret = snprintf(&buf[len], MAX_CMDLEN - len, " %s", + pp->args[i]); + if (ret <= 0 || ret >= MAX_CMDLEN - len) + goto error; + len += ret; + } + pp->found = 1; + return pp->found; +error: + free(pp->probes[0]); + if (ret > 0) + ret = -E2BIG; + return ret; +} + +int cmd_probe(int argc, const char **argv, const char *prefix __used) +{ + int i, j, fd, ret; + struct probe_point *pp; + char buf[MAX_CMDLEN]; + + argc = parse_options(argc, argv, options, probe_usage, + PARSE_OPT_STOP_AT_NON_OPTION); + if (argc || session.nr_probe == 0) + usage_with_options(probe_usage, options); + +#ifdef NO_LIBDWARF + if (session.need_dwarf) + semantic_error("Dwarf-analysis is not supported"); +#endif + + /* Synthesize probes without dwarf */ + for (j = 0; j < session.nr_probe; j++) { +#ifndef NO_LIBDWARF + if (session.events[j][0] != 'r') { + session.need_dwarf = 1; + continue; + } +#endif + ret = synthesize_probepoint(&session.probes[j]); + if (ret == -E2BIG) + semantic_error("probe point is too long."); + else if (ret < 0) + die("snprintf"); + } + +#ifndef NO_LIBDWARF + if (!session.need_dwarf) + goto setup_probes; + + if (session.vmlinux) + fd = open(session.vmlinux, O_RDONLY); + else + fd = open_default_vmlinux(); + if (fd < 0) + die("vmlinux/module file open"); + + /* Searching probe points */ + for (j = 0; j < session.nr_probe; j++) { + pp = &session.probes[j]; + if (pp->found) + continue; + + lseek(fd, SEEK_SET, 0); + ret = find_probepoint(fd, pp); + if (ret <= 0) + die("No probe point found.\n"); + eprintf("probe event %s found\n", session.events[j]); + } + close(fd); + +setup_probes: +#endif /* !NO_LIBDWARF */ + + /* Settng up probe points */ + snprintf(buf, MAX_CMDLEN, "%s/../kprobe_events", debugfs_path); + fd = open(buf, O_WRONLY, O_APPEND); + if (fd < 0) + die("kprobe_events open"); + for (j = 0; j < session.nr_probe; j++) { + pp = &session.probes[j]; + if (pp->found == 1) { + snprintf(buf, MAX_CMDLEN, "%s %s\n", + session.events[j], pp->probes[0]); + write_new_event(fd, buf); + } else + for (i = 0; i < pp->found; i++) { + snprintf(buf, MAX_CMDLEN, "%s%d %s\n", + session.events[j], i, pp->probes[i]); + write_new_event(fd, buf); + } + } + close(fd); + return 0; +} + diff --git a/tools/perf/builtin.h b/tools/perf/builtin.h index e11d8d231c3..ad5f0f4c49e 100644 --- a/tools/perf/builtin.h +++ b/tools/perf/builtin.h @@ -25,5 +25,6 @@ extern int cmd_timechart(int argc, const char **argv, const char *prefix); extern int cmd_top(int argc, const char **argv, const char *prefix); extern int cmd_trace(int argc, const char **argv, const char *prefix); extern int cmd_version(int argc, const char **argv, const char *prefix); +extern int cmd_probe(int argc, const char **argv, const char *prefix); #endif diff --git a/tools/perf/command-list.txt b/tools/perf/command-list.txt index 00326e230d8..6475db4f194 100644 --- a/tools/perf/command-list.txt +++ b/tools/perf/command-list.txt @@ -11,3 +11,4 @@ perf-stat mainporcelain common perf-timechart mainporcelain common perf-top mainporcelain common perf-trace mainporcelain common +perf-probe mainporcelain common diff --git a/tools/perf/perf.c b/tools/perf/perf.c index 624e62d9d1e..9cafe546326 100644 --- a/tools/perf/perf.c +++ b/tools/perf/perf.c @@ -295,6 +295,7 @@ static void handle_internal_command(int argc, const char **argv) { "version", cmd_version, 0 }, { "trace", cmd_trace, 0 }, { "sched", cmd_sched, 0 }, + { "probe", cmd_probe, 0 }, }; unsigned int i; static const char ext[] = STRIP_EXTENSION; diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c new file mode 100644 index 00000000000..be997abdf5b --- /dev/null +++ b/tools/perf/util/probe-finder.c @@ -0,0 +1,677 @@ +/* + * probe-finder.c : C expression to kprobe event converter + * + * Written by Masami Hiramatsu <mhiramat@redhat.com> + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + */ + +#include <sys/utsname.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <errno.h> +#include <stdio.h> +#include <unistd.h> +#include <getopt.h> +#include <stdlib.h> +#include <string.h> +#include <stdarg.h> +#include <ctype.h> + +#include "event.h" +#include "debug.h" +#include "util.h" +#include "probe-finder.h" + + +/* Dwarf_Die Linkage to parent Die */ +struct die_link { + struct die_link *parent; /* Parent die */ + Dwarf_Die die; /* Current die */ +}; + +static Dwarf_Debug __dw_debug; +static Dwarf_Error __dw_error; + +/* + * Generic dwarf analysis helpers + */ + +#define X86_32_MAX_REGS 8 +const char *x86_32_regs_table[X86_32_MAX_REGS] = { + "%ax", + "%cx", + "%dx", + "%bx", + "$stack", /* Stack address instead of %sp */ + "%bp", + "%si", + "%di", +}; + +#define X86_64_MAX_REGS 16 +const char *x86_64_regs_table[X86_64_MAX_REGS] = { + "%ax", + "%dx", + "%cx", + "%bx", + "%si", + "%di", + "%bp", + "%sp", + "%r8", + "%r9", + "%r10", + "%r11", + "%r12", + "%r13", + "%r14", + "%r15", +}; + +/* TODO: switching by dwarf address size */ +#ifdef __x86_64__ +#define ARCH_MAX_REGS X86_64_MAX_REGS +#define arch_regs_table x86_64_regs_table +#else +#define ARCH_MAX_REGS X86_32_MAX_REGS +#define arch_regs_table x86_32_regs_table +#endif + +/* Return architecture dependent register string (for kprobe-tracer) */ +static const char *get_arch_regstr(unsigned int n) +{ + return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL; +} + +/* + * Compare the tail of two strings. + * Return 0 if whole of either string is same as another's tail part. + */ +static int strtailcmp(const char *s1, const char *s2) +{ + int i1 = strlen(s1); + int i2 = strlen(s2); + while (--i1 > 0 && --i2 > 0) { + if (s1[i1] != s2[i2]) + return s1[i1] - s2[i2]; + } + return 0; +} + +/* Find the fileno of the target file. */ +static Dwarf_Unsigned die_get_fileno(Dwarf_Die cu_die, const char *fname) +{ + Dwarf_Signed cnt, i; + Dwarf_Unsigned found = 0; + char **srcs; + int ret; + + if (!fname) + return 0; + + ret = dwarf_srcfiles(cu_die, &srcs, &cnt, &__dw_error); + if (ret == DW_DLV_OK) { + for (i = 0; i < cnt && !found; i++) { + if (strtailcmp(srcs[i], fname) == 0) + found = i + 1; + dwarf_dealloc(__dw_debug, srcs[i], DW_DLA_STRING); + } + for (; i < cnt; i++) + dwarf_dealloc(__dw_debug, srcs[i], DW_DLA_STRING); + dwarf_dealloc(__dw_debug, srcs, DW_DLA_LIST); + } + if (found) + eprintf("found fno: %d\n", (int)found); + return found; +} + +/* Compare diename and tname */ +static int die_compare_name(Dwarf_Die dw_die, const char *tname) +{ + char *name; + int ret; + ret = dwarf_diename(dw_die, &name, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + if (ret == DW_DLV_OK) { + ret = strcmp(tname, name); + dwarf_dealloc(__dw_debug, name, DW_DLA_STRING); + } else + ret = -1; + return ret; +} + +/* Check the address is in the subprogram(function). */ +static int die_within_subprogram(Dwarf_Die sp_die, Dwarf_Addr addr, + Dwarf_Signed *offs) +{ + Dwarf_Addr lopc, hipc; + int ret; + + /* TODO: check ranges */ + ret = dwarf_lowpc(sp_die, &lopc, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + if (ret == DW_DLV_NO_ENTRY) + return 0; + ret = dwarf_highpc(sp_die, &hipc, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + if (lopc <= addr && addr < hipc) { + *offs = addr - lopc; + return 1; + } else + return 0; +} + +/* Check the die is inlined function */ +static Dwarf_Bool die_inlined_subprogram(Dwarf_Die dw_die) +{ + /* TODO: check strictly */ + Dwarf_Bool inl; + int ret; + + ret = dwarf_hasattr(dw_die, DW_AT_inline, &inl, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + return inl; +} + +/* Get the offset of abstruct_origin */ +static Dwarf_Off die_get_abstract_origin(Dwarf_Die dw_die) +{ + Dwarf_Attribute attr; + Dwarf_Off cu_offs; + int ret; + + ret = dwarf_attr(dw_die, DW_AT_abstract_origin, &attr, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + ret = dwarf_formref(attr, &cu_offs, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR); + return cu_offs; +} + +/* Get entry pc(or low pc, 1st entry of ranges) of the die */ +static Dwarf_Addr die_get_entrypc(Dwarf_Die dw_die) +{ + Dwarf_Attribute attr; + Dwarf_Addr addr; + Dwarf_Off offs; + Dwarf_Ranges *ranges; + Dwarf_Signed cnt; + int ret; + + /* Try to get entry pc */ + ret = dwarf_attr(dw_die, DW_AT_entry_pc, &attr, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + if (ret == DW_DLV_OK) { + ret = dwarf_formaddr(attr, &addr, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR); + return addr; + } + + /* Try to get low pc */ + ret = dwarf_lowpc(dw_die, &addr, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + if (ret == DW_DLV_OK) + return addr; + + /* Try to get ranges */ + ret = dwarf_attr(dw_die, DW_AT_ranges, &attr, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + ret = dwarf_formref(attr, &offs, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + ret = dwarf_get_ranges(__dw_debug, offs, &ranges, &cnt, NULL, + &__dw_error); + DIE_IF(ret != DW_DLV_OK); + addr = ranges[0].dwr_addr1; + dwarf_ranges_dealloc(__dw_debug, ranges, cnt); + return addr; +} + +/* + * Search a Die from Die tree. + * Note: cur_link->die should be deallocated in this function. + */ +static int __search_die_tree(struct die_link *cur_link, + int (*die_cb)(struct die_link *, void *), + void *data) +{ + Dwarf_Die new_die; + struct die_link new_link; + int ret; + + if (!die_cb) + return 0; + + /* Check current die */ + while (!(ret = die_cb(cur_link, data))) { + /* Check child die */ + ret = dwarf_child(cur_link->die, &new_die, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + if (ret == DW_DLV_OK) { + new_link.parent = cur_link; + new_link.die = new_die; + ret = __search_die_tree(&new_link, die_cb, data); + if (ret) + break; + } + + /* Move to next sibling */ + ret = dwarf_siblingof(__dw_debug, cur_link->die, &new_die, + &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + dwarf_dealloc(__dw_debug, cur_link->die, DW_DLA_DIE); + cur_link->die = new_die; + if (ret == DW_DLV_NO_ENTRY) + return 0; + } + dwarf_dealloc(__dw_debug, cur_link->die, DW_DLA_DIE); + return ret; +} + +/* Search a die in its children's die tree */ +static int search_die_from_children(Dwarf_Die parent_die, + int (*die_cb)(struct die_link *, void *), + void *data) +{ + struct die_link new_link; + int ret; + + new_link.parent = NULL; + ret = dwarf_child(parent_die, &new_link.die, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + if (ret == DW_DLV_OK) + return __search_die_tree(&new_link, die_cb, data); + else + return 0; +} + +/* Find a locdesc corresponding to the address */ +static int attr_get_locdesc(Dwarf_Attribute attr, Dwarf_Locdesc *desc, + Dwarf_Addr addr) +{ + Dwarf_Signed lcnt; + Dwarf_Locdesc **llbuf; + int ret, i; + + ret = dwarf_loclist_n(attr, &llbuf, &lcnt, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + ret = DW_DLV_NO_ENTRY; + for (i = 0; i < lcnt; ++i) { + if (llbuf[i]->ld_lopc <= addr && + llbuf[i]->ld_hipc > addr) { + memcpy(desc, llbuf[i], sizeof(Dwarf_Locdesc)); + desc->ld_s = + malloc(sizeof(Dwarf_Loc) * llbuf[i]->ld_cents); + DIE_IF(desc->ld_s == NULL); + memcpy(desc->ld_s, llbuf[i]->ld_s, + sizeof(Dwarf_Loc) * llbuf[i]->ld_cents); + ret = DW_DLV_OK; + break; + } + dwarf_dealloc(__dw_debug, llbuf[i]->ld_s, DW_DLA_LOC_BLOCK); + dwarf_dealloc(__dw_debug, llbuf[i], DW_DLA_LOCDESC); + } + /* Releasing loop */ + for (; i < lcnt; ++i) { + dwarf_dealloc(__dw_debug, llbuf[i]->ld_s, DW_DLA_LOC_BLOCK); + dwarf_dealloc(__dw_debug, llbuf[i], DW_DLA_LOCDESC); + } + dwarf_dealloc(__dw_debug, llbuf, DW_DLA_LIST); + return ret; +} + +/* + * Probe finder related functions + */ + +/* Show a location */ +static void show_location(Dwarf_Loc *loc, struct probe_finder *pf) +{ + Dwarf_Small op; + Dwarf_Unsigned regn; + Dwarf_Signed offs; + int deref = 0, ret; + const char *regs; + + op = loc->lr_atom; + + /* If this is based on frame buffer, set the offset */ + if (op == DW_OP_fbreg) { + deref = 1; + offs = (Dwarf_Signed)loc->lr_number; + op = pf->fbloc.ld_s[0].lr_atom; + loc = &pf->fbloc.ld_s[0]; + } else + offs = 0; + + if (op >= DW_OP_breg0 && op <= DW_OP_breg31) { + regn = op - DW_OP_breg0; + offs += (Dwarf_Signed)loc->lr_number; + deref = 1; + } else if (op >= DW_OP_reg0 && op <= DW_OP_reg31) { + regn = op - DW_OP_reg0; + } else if (op == DW_OP_bregx) { + regn = loc->lr_number; + offs += (Dwarf_Signed)loc->lr_number2; + deref = 1; + } else if (op == DW_OP_regx) { + regn = loc->lr_number; + } else + die("Dwarf_OP %d is not supported.\n", op); + + regs = get_arch_regstr(regn); + if (!regs) + die("%lld exceeds max register number.\n", regn); + + if (deref) + ret = snprintf(pf->buf, pf->len, + " %s=%+lld(%s)", pf->var, offs, regs); + else + ret = snprintf(pf->buf, pf->len, " %s=%s", pf->var, regs); + DIE_IF(ret < 0); + DIE_IF(ret >= pf->len); +} + +/* Show a variables in kprobe event format */ +static void show_variable(Dwarf_Die vr_die, struct probe_finder *pf) +{ + Dwarf_Attribute attr; + Dwarf_Locdesc ld; + int ret; + + ret = dwarf_attr(vr_die, DW_AT_location, &attr, &__dw_error); + if (ret != DW_DLV_OK) + goto error; + ret = attr_get_locdesc(attr, &ld, (pf->addr - pf->cu_base)); + if (ret != DW_DLV_OK) + goto error; + /* TODO? */ + DIE_IF(ld.ld_cents != 1); + show_location(&ld.ld_s[0], pf); + free(ld.ld_s); + dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR); + return ; +error: + die("Failed to find the location of %s at this address.\n" + " Perhaps, it has been optimized out.\n", pf->var); +} + +static int variable_callback(struct die_link *dlink, void *data) +{ + struct probe_finder *pf = (struct probe_finder *)data; + Dwarf_Half tag; + int ret; + + ret = dwarf_tag(dlink->die, &tag, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + if ((tag == DW_TAG_formal_parameter || + tag == DW_TAG_variable) && + (die_compare_name(dlink->die, pf->var) == 0)) { + show_variable(dlink->die, pf); + return 1; + } + /* TODO: Support struct members and arrays */ + return 0; +} + +/* Find a variable in a subprogram die */ +static void find_variable(Dwarf_Die sp_die, struct probe_finder *pf) +{ + int ret; + + if (!is_c_varname(pf->var)) { + /* Output raw parameters */ + ret = snprintf(pf->buf, pf->len, " %s", pf->var); + DIE_IF(ret < 0); + DIE_IF(ret >= pf->len); + return ; + } + + eprintf("Searching '%s' variable in context.\n", pf->var); + /* Search child die for local variables and parameters. */ + ret = search_die_from_children(sp_die, variable_callback, pf); + if (!ret) + die("Failed to find '%s' in this function.\n", pf->var); +} + +/* Get a frame base on the address */ +static void get_current_frame_base(Dwarf_Die sp_die, struct probe_finder *pf) +{ + Dwarf_Attribute attr; + int ret; + + ret = dwarf_attr(sp_die, DW_AT_frame_base, &attr, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + ret = attr_get_locdesc(attr, &pf->fbloc, (pf->addr - pf->cu_base)); + DIE_IF(ret != DW_DLV_OK); + dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR); +} + +static void free_current_frame_base(struct probe_finder *pf) +{ + free(pf->fbloc.ld_s); + memset(&pf->fbloc, 0, sizeof(Dwarf_Locdesc)); +} + +/* Show a probe point to output buffer */ +static void show_probepoint(Dwarf_Die sp_die, Dwarf_Signed offs, + struct probe_finder *pf) +{ + struct probe_point *pp = pf->pp; + char *name; + char tmp[MAX_PROBE_BUFFER]; + int ret, i, len; + + /* Output name of probe point */ + ret = dwarf_diename(sp_die, &name, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + if (ret == DW_DLV_OK) { + ret = snprintf(tmp, MAX_PROBE_BUFFER, "%s+%u", name, + (unsigned int)offs); + dwarf_dealloc(__dw_debug, name, DW_DLA_STRING); + } else { + /* This function has no name. */ + ret = snprintf(tmp, MAX_PROBE_BUFFER, "0x%llx", pf->addr); + } + DIE_IF(ret < 0); + DIE_IF(ret >= MAX_PROBE_BUFFER); + len = ret; + + /* Find each argument */ + get_current_frame_base(sp_die, pf); + for (i = 0; i < pp->nr_args; i++) { + pf->var = pp->args[i]; + pf->buf = &tmp[len]; + pf->len = MAX_PROBE_BUFFER - len; + find_variable(sp_die, pf); + len += strlen(pf->buf); + } + free_current_frame_base(pf); + + pp->probes[pp->found] = strdup(tmp); + pp->found++; +} + +static int probeaddr_callback(struct die_link *dlink, void *data) +{ + struct probe_finder *pf = (struct probe_finder *)data; + Dwarf_Half tag; + Dwarf_Signed offs; + int ret; + + ret = dwarf_tag(dlink->die, &tag, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + /* Check the address is in this subprogram */ + if (tag == DW_TAG_subprogram && + die_within_subprogram(dlink->die, pf->addr, &offs)) { + show_probepoint(dlink->die, offs, pf); + return 1; + } + return 0; +} + +/* Find probe point from its line number */ +static void find_by_line(Dwarf_Die cu_die, struct probe_finder *pf) +{ + struct probe_point *pp = pf->pp; + Dwarf_Signed cnt, i; + Dwarf_Line *lines; + Dwarf_Unsigned lineno = 0; + Dwarf_Addr addr; + Dwarf_Unsigned fno; + int ret; + + ret = dwarf_srclines(cu_die, &lines, &cnt, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + + for (i = 0; i < cnt; i++) { + ret = dwarf_line_srcfileno(lines[i], &fno, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + if (fno != pf->fno) + continue; + + ret = dwarf_lineno(lines[i], &lineno, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + if (lineno != (Dwarf_Unsigned)pp->line) + continue; + + ret = dwarf_lineaddr(lines[i], &addr, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + eprintf("Probe point found: 0x%llx\n", addr); + pf->addr = addr; + /* Search a real subprogram including this line, */ + ret = search_die_from_children(cu_die, probeaddr_callback, pf); + if (ret == 0) + die("Probe point is not found in subprograms.\n"); + /* Continuing, because target line might be inlined. */ + } + dwarf_srclines_dealloc(__dw_debug, lines, cnt); +} + +/* Search function from function name */ +static int probefunc_callback(struct die_link *dlink, void *data) +{ + struct probe_finder *pf = (struct probe_finder *)data; + struct probe_point *pp = pf->pp; + struct die_link *lk; + Dwarf_Signed offs; + Dwarf_Half tag; + int ret; + + ret = dwarf_tag(dlink->die, &tag, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + if (tag == DW_TAG_subprogram) { + if (die_compare_name(dlink->die, pp->function) == 0) { + if (die_inlined_subprogram(dlink->die)) { + /* Inlined function, save it. */ + ret = dwarf_die_CU_offset(dlink->die, + &pf->inl_offs, + &__dw_error); + DIE_IF(ret != DW_DLV_OK); + eprintf("inline definition offset %lld\n", + pf->inl_offs); + return 0; + } + /* Get probe address */ + pf->addr = die_get_entrypc(dlink->die); + pf->addr += pp->offset; + /* TODO: Check the address in this function */ + show_probepoint(dlink->die, pp->offset, pf); + /* Continue to search */ + } + } else if (tag == DW_TAG_inlined_subroutine && pf->inl_offs) { + if (die_get_abstract_origin(dlink->die) == pf->inl_offs) { + /* Get probe address */ + pf->addr = die_get_entrypc(dlink->die); + pf->addr += pp->offset; + eprintf("found inline addr: 0x%llx\n", pf->addr); + /* Inlined function. Get a real subprogram */ + for (lk = dlink->parent; lk != NULL; lk = lk->parent) { + tag = 0; + dwarf_tag(lk->die, &tag, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + if (tag == DW_TAG_subprogram && + !die_inlined_subprogram(lk->die)) + goto found; + } + die("Failed to find real subprogram.\n"); +found: + /* Get offset from subprogram */ + ret = die_within_subprogram(lk->die, pf->addr, &offs); + DIE_IF(!ret); + show_probepoint(lk->die, offs, pf); + /* Continue to search */ + } + } + return 0; +} + +static void find_by_func(Dwarf_Die cu_die, struct probe_finder *pf) +{ + search_die_from_children(cu_die, probefunc_callback, pf); +} + +/* Find a probe point */ +int find_probepoint(int fd, struct probe_point *pp) +{ + Dwarf_Half addr_size = 0; + Dwarf_Unsigned next_cuh = 0; + Dwarf_Die cu_die = 0; + int cu_number = 0, ret; + struct probe_finder pf = {.pp = pp}; + + ret = dwarf_init(fd, DW_DLC_READ, 0, 0, &__dw_debug, &__dw_error); + if (ret != DW_DLV_OK) + die("Failed to call dwarf_init(). Maybe, not a dwarf file.\n"); + + pp->found = 0; + while (++cu_number) { + /* Search CU (Compilation Unit) */ + ret = dwarf_next_cu_header(__dw_debug, NULL, NULL, NULL, + &addr_size, &next_cuh, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + if (ret == DW_DLV_NO_ENTRY) + break; + + /* Get the DIE(Debugging Information Entry) of this CU */ + ret = dwarf_siblingof(__dw_debug, 0, &cu_die, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + + /* Check if target file is included. */ + if (pp->file) + pf.fno = die_get_fileno(cu_die, pp->file); + + if (!pp->file || pf.fno) { + /* Save CU base address (for frame_base) */ + ret = dwarf_lowpc(cu_die, &pf.cu_base, &__dw_error); + DIE_IF(ret == DW_DLV_ERROR); + if (ret == DW_DLV_NO_ENTRY) + pf.cu_base = 0; + if (pp->line) + find_by_line(cu_die, &pf); + if (pp->function) + find_by_func(cu_die, &pf); + } + dwarf_dealloc(__dw_debug, cu_die, DW_DLA_DIE); + } + ret = dwarf_finish(__dw_debug, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + + return pp->found; +} + diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h new file mode 100644 index 00000000000..d17fafc2135 --- /dev/null +++ b/tools/perf/util/probe-finder.h @@ -0,0 +1,53 @@ +#ifndef _PROBE_FINDER_H +#define _PROBE_FINDER_H + +#define MAX_PATH_LEN 256 +#define MAX_PROBE_BUFFER 1024 +#define MAX_PROBES 128 + +static inline int is_c_varname(const char *name) +{ + /* TODO */ + return isalpha(name[0]) || name[0] == '_'; +} + +struct probe_point { + /* Inputs */ + char *file; /* File name */ + int line; /* Line number */ + + char *function; /* Function name */ + int offset; /* Offset bytes */ + + int nr_args; /* Number of arguments */ + char **args; /* Arguments */ + + /* Output */ + int found; /* Number of found probe points */ + char *probes[MAX_PROBES]; /* Output buffers (will be allocated)*/ +}; + +#ifndef NO_LIBDWARF +extern int find_probepoint(int fd, struct probe_point *pp); + +#include <libdwarf/dwarf.h> +#include <libdwarf/libdwarf.h> + +struct probe_finder { + struct probe_point *pp; /* Target probe point */ + + /* For function searching */ + Dwarf_Addr addr; /* Address */ + Dwarf_Unsigned fno; /* File number */ + Dwarf_Off inl_offs; /* Inline offset */ + + /* For variable searching */ + Dwarf_Addr cu_base; /* Current CU base address */ + Dwarf_Locdesc fbloc; /* Location of Current Frame Base */ + const char *var; /* Current variable name */ + char *buf; /* Current output buffer */ + int len; /* Length of output buffer */ +}; +#endif /* NO_LIBDWARF */ + +#endif /*_PROBE_FINDER_H */ diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h index 9de2329dd44..0daa341734f 100644 --- a/tools/perf/util/util.h +++ b/tools/perf/util/util.h @@ -134,6 +134,15 @@ extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, extern int error(const char *err, ...) __attribute__((format (printf, 1, 2))); extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2))); +#include "../../../include/linux/stringify.h" + +#define DIE_IF(cnd) \ + do { if (cnd) \ + die(" at (" __FILE__ ":" __stringify(__LINE__) "): " \ + __stringify(cnd) "\n"); \ + } while (0) + + extern void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN); extern int prefixcmp(const char *str, const char *prefix); |