From 469b9b88488e89114bb3e9ac5ee7906b7b96123f Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 21 Oct 2010 19:13:41 +0900 Subject: perf probe: Add basic module support Add basic module probe support on perf probe. This introduces "--module " option to perf probe for putting probes and showing lines and variables in the given module. Currently, this supports only probing on running modules. Supporting off-line module probing is the next step. e.g.) [show lines] # ./perf probe --module drm -L drm_vblank_info 0 int drm_vblank_info(struct seq_file *m, void *data) 1 { struct drm_info_node *node = (struct drm_info_node *) m->private 3 struct drm_device *dev = node->minor->dev; ... [show vars] # ./perf probe --module drm -V drm_vblank_info:3 Available variables at drm_vblank_info:3 @ (unknown_type) data struct drm_info_node* node struct seq_file* m [put a probe] # ./perf probe --module drm drm_vblank_info:3 node m Add new event: probe:drm_vblank_info (on drm_vblank_info:3 with node m) You can now use it on all perf tools, such as: perf record -e probe:drm_vblank_info -aR sleep 1 [list probes] # ./perf probe -l probe:drm_vblank_info (on drm_vblank_info:3@drivers/gpu/drm/drm_info.c with ... Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Ingo Molnar Cc: Frederic Weisbecker LKML-Reference: <20101021101341.3542.71638.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-probe.txt | 9 +- tools/perf/builtin-probe.c | 11 ++- tools/perf/util/map.h | 10 +++ tools/perf/util/probe-event.c | 123 +++++++++++++++++---------- tools/perf/util/probe-event.h | 10 ++- tools/perf/util/probe-finder.c | 142 ++++++++++++++++++++++++++++---- tools/perf/util/probe-finder.h | 3 +- 7 files changed, 239 insertions(+), 69 deletions(-) (limited to 'tools') diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt index 148c178..62de1b7 100644 --- a/tools/perf/Documentation/perf-probe.txt +++ b/tools/perf/Documentation/perf-probe.txt @@ -16,9 +16,9 @@ or or 'perf probe' --list or -'perf probe' --line='FUNC[:RLN[+NUM|:RLN2]]|SRC:ALN[+NUM|:ALN2]' +'perf probe' [options] --line='FUNC[:RLN[+NUM|:RLN2]]|SRC:ALN[+NUM|:ALN2]' or -'perf probe' [--externs] --vars='PROBEPOINT' +'perf probe' [options] --vars='PROBEPOINT' DESCRIPTION ----------- @@ -33,6 +33,11 @@ OPTIONS --vmlinux=PATH:: Specify vmlinux path which has debuginfo (Dwarf binary). +-m:: +--module=MODNAME:: + Specify module name in which perf-probe searches probe points + or lines. + -s:: --source=PATH:: Specify path to kernel source. diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c index bdf60cf..2e000c0 100644 --- a/tools/perf/builtin-probe.c +++ b/tools/perf/builtin-probe.c @@ -57,6 +57,7 @@ static struct { struct perf_probe_event events[MAX_PROBES]; struct strlist *dellist; struct line_range line_range; + const char *target_module; int max_probe_points; } params; @@ -162,8 +163,8 @@ static const char * const probe_usage[] = { "perf probe [] --del '[GROUP:]EVENT' ...", "perf probe --list", #ifdef DWARF_SUPPORT - "perf probe --line 'LINEDESC'", - "perf probe [--externs] --vars 'PROBEPOINT'", + "perf probe [] --line 'LINEDESC'", + "perf probe [] --vars 'PROBEPOINT'", #endif NULL }; @@ -214,6 +215,8 @@ static const struct option options[] = { "file", "vmlinux pathname"), OPT_STRING('s', "source", &symbol_conf.source_prefix, "directory", "path to kernel source"), + OPT_STRING('m', "module", ¶ms.target_module, + "modname", "target module name"), #endif OPT__DRY_RUN(&probe_event_dry_run), OPT_INTEGER('\0', "max-probes", ¶ms.max_probe_points, @@ -278,7 +281,7 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used) usage_with_options(probe_usage, options); } - ret = show_line_range(¶ms.line_range); + ret = show_line_range(¶ms.line_range, params.target_module); if (ret < 0) pr_err(" Error: Failed to show lines. (%d)\n", ret); return ret; @@ -291,6 +294,7 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used) } ret = show_available_vars(params.events, params.nevents, params.max_probe_points, + params.target_module, params.show_ext_vars); if (ret < 0) pr_err(" Error: Failed to show vars. (%d)\n", ret); @@ -310,6 +314,7 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used) if (params.nevents) { ret = add_perf_probe_events(params.events, params.nevents, params.max_probe_points, + params.target_module, params.force_add); if (ret < 0) { pr_err(" Error: Failed to add events. (%d)\n", ret); diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h index 7857579..b397c03 100644 --- a/tools/perf/util/map.h +++ b/tools/perf/util/map.h @@ -215,6 +215,16 @@ struct symbol *map_groups__find_function_by_name(struct map_groups *self, return map_groups__find_symbol_by_name(self, MAP__FUNCTION, name, mapp, filter); } +static inline +struct symbol *machine__find_kernel_function_by_name(struct machine *self, + const char *name, + struct map **mapp, + symbol_filter_t filter) +{ + return map_groups__find_function_by_name(&self->kmaps, name, mapp, + filter); +} + int map_groups__fixup_overlappings(struct map_groups *self, struct map *map, int verbose, FILE *fp); diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 82b0976..3b6a529 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -74,10 +74,9 @@ static int e_snprintf(char *str, size_t size, const char *format, ...) static char *synthesize_perf_probe_point(struct perf_probe_point *pp); static struct machine machine; -/* Initialize symbol maps and path of vmlinux */ +/* Initialize symbol maps and path of vmlinux/modules */ static int init_vmlinux(void) { - struct dso *kernel; int ret; symbol_conf.sort_by_name = true; @@ -91,33 +90,61 @@ static int init_vmlinux(void) goto out; } - ret = machine__init(&machine, "/", 0); + ret = machine__init(&machine, "", HOST_KERNEL_ID); if (ret < 0) goto out; - kernel = dso__new_kernel(symbol_conf.vmlinux_name); - if (kernel == NULL) - die("Failed to create kernel dso."); - - ret = __machine__create_kernel_maps(&machine, kernel); - if (ret < 0) - pr_debug("Failed to create kernel maps.\n"); - + if (machine__create_kernel_maps(&machine) < 0) { + pr_debug("machine__create_kernel_maps "); + goto out; + } out: if (ret < 0) pr_warning("Failed to init vmlinux path.\n"); return ret; } +static struct symbol *__find_kernel_function_by_name(const char *name, + struct map **mapp) +{ + return machine__find_kernel_function_by_name(&machine, name, mapp, + NULL); +} + +const char *kernel_get_module_path(const char *module) +{ + struct dso *dso; + + if (module) { + list_for_each_entry(dso, &machine.kernel_dsos, node) { + if (strncmp(dso->short_name + 1, module, + dso->short_name_len - 2) == 0) + goto found; + } + pr_debug("Failed to find module %s.\n", module); + return NULL; + } else { + dso = machine.vmlinux_maps[MAP__FUNCTION]->dso; + if (dso__load_vmlinux_path(dso, + machine.vmlinux_maps[MAP__FUNCTION], NULL) < 0) { + pr_debug("Failed to load kernel map.\n"); + return NULL; + } + } +found: + return dso->long_name; +} + #ifdef DWARF_SUPPORT -static int open_vmlinux(void) +static int open_vmlinux(const char *module) { - if (map__load(machine.vmlinux_maps[MAP__FUNCTION], NULL) < 0) { - pr_debug("Failed to load kernel map.\n"); - return -EINVAL; + const char *path = kernel_get_module_path(module); + if (!path) { + pr_err("Failed to find path of %s module", module ?: "kernel"); + return -ENOENT; } - pr_debug("Try to open %s\n", machine.vmlinux_maps[MAP__FUNCTION]->dso->long_name); - return open(machine.vmlinux_maps[MAP__FUNCTION]->dso->long_name, O_RDONLY); + pr_debug("Try to open %s\n", path); + return open(path, O_RDONLY); } /* @@ -125,20 +152,19 @@ static int open_vmlinux(void) * Currently only handles kprobes. */ static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp, - struct perf_probe_point *pp) + struct perf_probe_point *pp) { struct symbol *sym; - int fd, ret = -ENOENT; + struct map *map; + u64 addr; + int ret = -ENOENT; - sym = map__find_symbol_by_name(machine.vmlinux_maps[MAP__FUNCTION], - tp->symbol, NULL); + sym = __find_kernel_function_by_name(tp->symbol, &map); if (sym) { - fd = open_vmlinux(); - if (fd >= 0) { - ret = find_perf_probe_point(fd, - sym->start + tp->offset, pp); - close(fd); - } + addr = map->unmap_ip(map, sym->start + tp->offset); + pr_debug("try to find %s+%ld@%llx\n", tp->symbol, + tp->offset, addr); + ret = find_perf_probe_point((unsigned long)addr, pp); } if (ret <= 0) { pr_debug("Failed to find corresponding probes from " @@ -156,12 +182,12 @@ static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp, /* Try to find perf_probe_event with debuginfo */ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, struct probe_trace_event **tevs, - int max_tevs) + int max_tevs, const char *module) { bool need_dwarf = perf_probe_event_need_dwarf(pev); int fd, ntevs; - fd = open_vmlinux(); + fd = open_vmlinux(module); if (fd < 0) { if (need_dwarf) { pr_warning("Failed to open debuginfo file.\n"); @@ -300,7 +326,7 @@ error: * Show line-range always requires debuginfo to find source file and * line number. */ -int show_line_range(struct line_range *lr) +int show_line_range(struct line_range *lr, const char *module) { int l = 1; struct line_node *ln; @@ -313,7 +339,7 @@ int show_line_range(struct line_range *lr) if (ret < 0) return ret; - fd = open_vmlinux(); + fd = open_vmlinux(module); if (fd < 0) { pr_warning("Failed to open debuginfo file.\n"); return fd; @@ -421,7 +447,7 @@ static int show_available_vars_at(int fd, struct perf_probe_event *pev, /* Show available variables on given probe point */ int show_available_vars(struct perf_probe_event *pevs, int npevs, - int max_vls, bool externs) + int max_vls, const char *module, bool externs) { int i, fd, ret = 0; @@ -429,7 +455,7 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs, if (ret < 0) return ret; - fd = open_vmlinux(); + fd = open_vmlinux(module); if (fd < 0) { pr_warning("Failed to open debuginfo file.\n"); return fd; @@ -447,8 +473,15 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs, #else /* !DWARF_SUPPORT */ static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp, - struct perf_probe_point *pp) + struct perf_probe_point *pp) { + struct symbol *sym; + + sym = __find_kernel_function_by_name(tp->symbol, NULL); + if (!sym) { + pr_err("Failed to find symbol %s in kernel.\n", tp->symbol); + return -ENOENT; + } pp->function = strdup(tp->symbol); if (pp->function == NULL) return -ENOMEM; @@ -460,7 +493,7 @@ static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp, static int try_to_find_probe_trace_events(struct perf_probe_event *pev, struct probe_trace_event **tevs __unused, - int max_tevs __unused) + int max_tevs __unused, const char *mod __unused) { if (perf_probe_event_need_dwarf(pev)) { pr_warning("Debuginfo-analysis is not supported.\n"); @@ -469,14 +502,15 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, return 0; } -int show_line_range(struct line_range *lr __unused) +int show_line_range(struct line_range *lr __unused, const char *module __unused) { pr_warning("Debuginfo-analysis is not supported.\n"); return -ENOSYS; } int show_available_vars(struct perf_probe_event *pevs __unused, - int npevs __unused, int max_probe_points __unused) + int npevs __unused, int max_vls __unused, + const char *module __unused, bool externs __unused) { pr_warning("Debuginfo-analysis is not supported.\n"); return -ENOSYS; @@ -1159,7 +1193,7 @@ error: } static int convert_to_perf_probe_event(struct probe_trace_event *tev, - struct perf_probe_event *pev) + struct perf_probe_event *pev) { char buf[64] = ""; int i, ret; @@ -1588,14 +1622,14 @@ static int __add_probe_trace_events(struct perf_probe_event *pev, static int convert_to_probe_trace_events(struct perf_probe_event *pev, struct probe_trace_event **tevs, - int max_tevs) + int max_tevs, const char *module) { struct symbol *sym; int ret = 0, i; struct probe_trace_event *tev; /* Convert perf_probe_event with debuginfo */ - ret = try_to_find_probe_trace_events(pev, tevs, max_tevs); + ret = try_to_find_probe_trace_events(pev, tevs, max_tevs, module); if (ret != 0) return ret; @@ -1644,8 +1678,7 @@ static int convert_to_probe_trace_events(struct perf_probe_event *pev, } /* Currently just checking function name from symbol map */ - sym = map__find_symbol_by_name(machine.vmlinux_maps[MAP__FUNCTION], - tev->point.symbol, NULL); + sym = __find_kernel_function_by_name(tev->point.symbol, NULL); if (!sym) { pr_warning("Kernel symbol \'%s\' not found.\n", tev->point.symbol); @@ -1668,7 +1701,7 @@ struct __event_package { }; int add_perf_probe_events(struct perf_probe_event *pevs, int npevs, - int max_tevs, bool force_add) + int max_tevs, const char *module, bool force_add) { int i, j, ret; struct __event_package *pkgs; @@ -1689,7 +1722,9 @@ int add_perf_probe_events(struct perf_probe_event *pevs, int npevs, pkgs[i].pev = &pevs[i]; /* Convert with or without debuginfo */ ret = convert_to_probe_trace_events(pkgs[i].pev, - &pkgs[i].tevs, max_tevs); + &pkgs[i].tevs, + max_tevs, + module); if (ret < 0) goto end; pkgs[i].ntevs = ret; diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h index c74b1fd..5accbed 100644 --- a/tools/perf/util/probe-event.h +++ b/tools/perf/util/probe-event.h @@ -115,14 +115,18 @@ extern void clear_perf_probe_event(struct perf_probe_event *pev); /* Command string to line-range */ extern int parse_line_range_desc(const char *cmd, struct line_range *lr); +/* Internal use: Return kernel/module path */ +extern const char *kernel_get_module_path(const char *module); extern int add_perf_probe_events(struct perf_probe_event *pevs, int npevs, - int max_probe_points, bool force_add); + int max_probe_points, const char *module, + bool force_add); extern int del_perf_probe_events(struct strlist *dellist); extern int show_perf_probe_events(void); -extern int show_line_range(struct line_range *lr); +extern int show_line_range(struct line_range *lr, const char *module); extern int show_available_vars(struct perf_probe_event *pevs, int npevs, - int max_probe_points, bool externs); + int max_probe_points, const char *module, + bool externs); /* Maximum index number of event-name postfix */ diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index a274fd0..c20bd52 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -116,6 +116,101 @@ static void line_list__free(struct list_head *head) } } +/* Dwarf FL wrappers */ + +static int __linux_kernel_find_elf(Dwfl_Module *mod, + void **userdata, + const char *module_name, + Dwarf_Addr base, + char **file_name, Elf **elfp) +{ + int fd; + const char *path = kernel_get_module_path(module_name); + + if (path) { + fd = open(path, O_RDONLY); + if (fd >= 0) { + *file_name = strdup(path); + return fd; + } + } + /* If failed, try to call standard method */ + return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base, + file_name, elfp); +} + +static char *debuginfo_path; /* Currently dummy */ + +static const Dwfl_Callbacks offline_callbacks = { + .find_debuginfo = dwfl_standard_find_debuginfo, + .debuginfo_path = &debuginfo_path, + + .section_address = dwfl_offline_section_address, + + /* We use this table for core files too. */ + .find_elf = dwfl_build_id_find_elf, +}; + +static const Dwfl_Callbacks kernel_callbacks = { + .find_debuginfo = dwfl_standard_find_debuginfo, + .debuginfo_path = &debuginfo_path, + + .find_elf = __linux_kernel_find_elf, + .section_address = dwfl_linux_kernel_module_section_address, +}; + +/* Get a Dwarf from offline image */ +static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias) +{ + Dwfl_Module *mod; + Dwarf *dbg = NULL; + + if (!dwflp) + return NULL; + + *dwflp = dwfl_begin(&offline_callbacks); + if (!*dwflp) + return NULL; + + mod = dwfl_report_offline(*dwflp, "", "", fd); + if (!mod) + goto error; + + dbg = dwfl_module_getdwarf(mod, bias); + if (!dbg) { +error: + dwfl_end(*dwflp); + *dwflp = NULL; + } + return dbg; +} + +/* Get a Dwarf from live kernel image */ +static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp, + Dwarf_Addr *bias) +{ + Dwarf *dbg; + + if (!dwflp) + return NULL; + + *dwflp = dwfl_begin(&kernel_callbacks); + if (!*dwflp) + return NULL; + + /* Load the kernel dwarves: Don't care the result here */ + dwfl_linux_kernel_report_kernel(*dwflp); + dwfl_linux_kernel_report_modules(*dwflp); + + dbg = dwfl_addrdwarf(*dwflp, addr, bias); + /* Here, check whether we could get a real dwarf */ + if (!dbg) { + dwfl_end(*dwflp); + *dwflp = NULL; + } + return dbg; +} + /* Dwarf wrappers */ /* Find the realpath of the target file. */ @@ -1177,10 +1272,12 @@ static int find_probes(int fd, struct probe_finder *pf) Dwarf_Off off, noff; size_t cuhl; Dwarf_Die *diep; - Dwarf *dbg; + Dwarf *dbg = NULL; + Dwfl *dwfl; + Dwarf_Addr bias; /* Currently ignored */ int ret = 0; - dbg = dwarf_begin(fd, DWARF_C_READ); + dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias); if (!dbg) { pr_warning("No dwarf info found in the vmlinux - " "please rebuild with CONFIG_DEBUG_INFO=y.\n"); @@ -1221,7 +1318,8 @@ static int find_probes(int fd, struct probe_finder *pf) off = noff; } line_list__free(&pf->lcache); - dwarf_end(dbg); + if (dwfl) + dwfl_end(dwfl); return ret; } @@ -1412,23 +1510,31 @@ int find_available_vars_at(int fd, struct perf_probe_event *pev, } /* Reverse search */ -int find_perf_probe_point(int fd, unsigned long addr, - struct perf_probe_point *ppt) +int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt) { Dwarf_Die cudie, spdie, indie; - Dwarf *dbg; + Dwarf *dbg = NULL; + Dwfl *dwfl = NULL; Dwarf_Line *line; - Dwarf_Addr laddr, eaddr; + Dwarf_Addr laddr, eaddr, bias = 0; const char *tmp; int lineno, ret = 0; bool found = false; - dbg = dwarf_begin(fd, DWARF_C_READ); - if (!dbg) - return -EBADF; + /* Open the live linux kernel */ + dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias); + if (!dbg) { + pr_warning("No dwarf info found in the vmlinux - " + "please rebuild with CONFIG_DEBUG_INFO=y.\n"); + ret = -EINVAL; + goto end; + } + /* Adjust address with bias */ + addr += bias; /* Find cu die */ - if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) { + if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) { + pr_warning("No CU DIE is found at %lx\n", addr); ret = -EINVAL; goto end; } @@ -1491,7 +1597,8 @@ found: } end: - dwarf_end(dbg); + if (dwfl) + dwfl_end(dwfl); if (ret >= 0) ret = found ? 1 : 0; return ret; @@ -1624,6 +1731,8 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data) struct line_finder *lf = param->data; struct line_range *lr = lf->lr; + pr_debug("find (%lx) %s\n", dwarf_dieoffset(sp_die), + dwarf_diename(sp_die)); if (dwarf_tag(sp_die) == DW_TAG_subprogram && die_compare_name(sp_die, lr->function)) { lf->fname = dwarf_decl_file(sp_die); @@ -1667,10 +1776,12 @@ int find_line_range(int fd, struct line_range *lr) Dwarf_Off off = 0, noff; size_t cuhl; Dwarf_Die *diep; - Dwarf *dbg; + Dwarf *dbg = NULL; + Dwfl *dwfl; + Dwarf_Addr bias; /* Currently ignored */ const char *comp_dir; - dbg = dwarf_begin(fd, DWARF_C_READ); + dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias); if (!dbg) { pr_warning("No dwarf info found in the vmlinux - " "please rebuild with CONFIG_DEBUG_INFO=y.\n"); @@ -1716,8 +1827,7 @@ int find_line_range(int fd, struct line_range *lr) } pr_debug("path: %s\n", lr->path); - dwarf_end(dbg); - + dwfl_end(dwfl); return (ret < 0) ? ret : lf.found; } diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h index 516912a..bba69d4 100644 --- a/tools/perf/util/probe-finder.h +++ b/tools/perf/util/probe-finder.h @@ -22,7 +22,7 @@ extern int find_probe_trace_events(int fd, struct perf_probe_event *pev, int max_tevs); /* Find a perf_probe_point from debuginfo */ -extern int find_perf_probe_point(int fd, unsigned long addr, +extern int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt); /* Find a line range */ @@ -35,6 +35,7 @@ extern int find_available_vars_at(int fd, struct perf_probe_event *pev, #include #include +#include #include struct probe_finder { -- cgit v1.1