From ff741783506c340035659a71be68ddb4068760d1 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Mon, 27 Jun 2011 16:27:39 +0900 Subject: [PATCH] perf probe: Introduce debuginfo to encapsulate dwarf information Introduce debuginfo to encapsulate dwarf information. This new object allows us to reuse and expand debuginfo easily. Signed-off-by: Masami Hiramatsu Cc: Peter Zijlstra Cc: Frederic Weisbecker Cc: Paul Mackerras Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Link: http://lkml.kernel.org/r/20110627072739.6528.12438.stgit@fedora15 Signed-off-by: Steven Rostedt --- tools/perf/util/probe-event.c | 78 ++++++++----- tools/perf/util/probe-finder.c | 203 +++++++++++++++++---------------- tools/perf/util/probe-finder.h | 39 +++++-- 3 files changed, 183 insertions(+), 137 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index f0223166e761..920c1957d6d3 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -170,16 +170,17 @@ const char *kernel_get_module_path(const char *module) } #ifdef DWARF_SUPPORT -static int open_vmlinux(const char *module) +/* Open new debuginfo of given module */ +static struct debuginfo *open_debuginfo(const char *module) { const char *path = kernel_get_module_path(module); + if (!path) { pr_err("Failed to find path of %s module.\n", module ?: "kernel"); - return -ENOENT; + return NULL; } - pr_debug("Try to open %s\n", path); - return open(path, O_RDONLY); + return debuginfo__new(path); } /* @@ -193,13 +194,24 @@ static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp, struct map *map; u64 addr; int ret = -ENOENT; + struct debuginfo *dinfo; sym = __find_kernel_function_by_name(tp->symbol, &map); if (sym) { addr = map->unmap_ip(map, sym->start + tp->offset); pr_debug("try to find %s+%ld@%" PRIx64 "\n", tp->symbol, tp->offset, addr); - ret = find_perf_probe_point((unsigned long)addr, pp); + + dinfo = debuginfo__new_online_kernel(addr); + if (dinfo) { + ret = debuginfo__find_probe_point(dinfo, + (unsigned long)addr, pp); + debuginfo__delete(dinfo); + } else { + pr_debug("Failed to open debuginfo at 0x%" PRIx64 "\n", + addr); + ret = -ENOENT; + } } if (ret <= 0) { pr_debug("Failed to find corresponding probes from " @@ -220,20 +232,22 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, int max_tevs, const char *module) { bool need_dwarf = perf_probe_event_need_dwarf(pev); - int fd, ntevs; + struct debuginfo *dinfo = open_debuginfo(module); + int ntevs; - fd = open_vmlinux(module); - if (fd < 0) { + if (!dinfo) { if (need_dwarf) { pr_warning("Failed to open debuginfo file.\n"); - return fd; + return -ENOENT; } - pr_debug("Could not open vmlinux. Try to use symbols.\n"); + pr_debug("Could not open debuginfo. Try to use symbols.\n"); return 0; } - /* Searching trace events corresponding to probe event */ - ntevs = find_probe_trace_events(fd, pev, tevs, max_tevs); + /* Searching trace events corresponding to a probe event */ + ntevs = debuginfo__find_trace_events(dinfo, pev, tevs, max_tevs); + + debuginfo__delete(dinfo); if (ntevs > 0) { /* Succeeded to find trace events */ pr_debug("find %d probe_trace_events.\n", ntevs); @@ -371,8 +385,9 @@ int show_line_range(struct line_range *lr, const char *module) { int l = 1; struct line_node *ln; + struct debuginfo *dinfo; FILE *fp; - int fd, ret; + int ret; char *tmp; /* Search a line range */ @@ -380,13 +395,14 @@ int show_line_range(struct line_range *lr, const char *module) if (ret < 0) return ret; - fd = open_vmlinux(module); - if (fd < 0) { + dinfo = open_debuginfo(module); + if (!dinfo) { pr_warning("Failed to open debuginfo file.\n"); - return fd; + return -ENOENT; } - ret = find_line_range(fd, lr); + ret = debuginfo__find_line_range(dinfo, lr); + debuginfo__delete(dinfo); if (ret == 0) { pr_warning("Specified source line is not found.\n"); return -ENOENT; @@ -448,7 +464,8 @@ end: return ret; } -static int show_available_vars_at(int fd, struct perf_probe_event *pev, +static int show_available_vars_at(struct debuginfo *dinfo, + struct perf_probe_event *pev, int max_vls, struct strfilter *_filter, bool externs) { @@ -463,7 +480,8 @@ static int show_available_vars_at(int fd, struct perf_probe_event *pev, return -EINVAL; pr_debug("Searching variables at %s\n", buf); - ret = find_available_vars_at(fd, pev, &vls, max_vls, externs); + ret = debuginfo__find_available_vars_at(dinfo, pev, &vls, + max_vls, externs); if (ret <= 0) { pr_err("Failed to find variables at %s (%d)\n", buf, ret); goto end; @@ -504,24 +522,26 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs, int max_vls, const char *module, struct strfilter *_filter, bool externs) { - int i, fd, ret = 0; + int i, ret = 0; + struct debuginfo *dinfo; ret = init_vmlinux(); if (ret < 0) return ret; + dinfo = open_debuginfo(module); + if (!dinfo) { + pr_warning("Failed to open debuginfo file.\n"); + return -ENOENT; + } + setup_pager(); - for (i = 0; i < npevs && ret >= 0; i++) { - fd = open_vmlinux(module); - if (fd < 0) { - pr_warning("Failed to open debug information file.\n"); - ret = fd; - break; - } - ret = show_available_vars_at(fd, &pevs[i], max_vls, _filter, + for (i = 0; i < npevs && ret >= 0; i++) + ret = show_available_vars_at(dinfo, &pevs[i], max_vls, _filter, externs); - } + + debuginfo__delete(dinfo); return ret; } diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 53d219bddb48..3e44a3e36519 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -116,29 +116,37 @@ static const Dwfl_Callbacks offline_callbacks = { }; /* Get a Dwarf from offline image */ -static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias) +static int debuginfo__init_offline_dwarf(struct debuginfo *self, + const char *path) { Dwfl_Module *mod; - Dwarf *dbg = NULL; + int fd; - if (!dwflp) - return NULL; + fd = open(path, O_RDONLY); + if (fd < 0) + return fd; - *dwflp = dwfl_begin(&offline_callbacks); - if (!*dwflp) - return NULL; + self->dwfl = dwfl_begin(&offline_callbacks); + if (!self->dwfl) + goto error; - mod = dwfl_report_offline(*dwflp, "", "", fd); + mod = dwfl_report_offline(self->dwfl, "", "", fd); if (!mod) goto error; - dbg = dwfl_module_getdwarf(mod, bias); - if (!dbg) { + self->dbg = dwfl_module_getdwarf(mod, &self->bias); + if (!self->dbg) + goto error; + + return 0; error: - dwfl_end(*dwflp); - *dwflp = NULL; - } - return dbg; + if (self->dwfl) + dwfl_end(self->dwfl); + else + close(fd); + memset(self, 0, sizeof(*self)); + + return -ENOENT; } #if _ELFUTILS_PREREQ(0, 148) @@ -174,54 +182,83 @@ static const Dwfl_Callbacks kernel_callbacks = { }; /* Get a Dwarf from live kernel image */ -static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp, - Dwarf_Addr *bias) +static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self, + Dwarf_Addr addr) { - Dwarf *dbg; - - if (!dwflp) - return NULL; - - *dwflp = dwfl_begin(&kernel_callbacks); - if (!*dwflp) - return NULL; + self->dwfl = dwfl_begin(&kernel_callbacks); + if (!self->dwfl) + return -EINVAL; /* Load the kernel dwarves: Don't care the result here */ - dwfl_linux_kernel_report_kernel(*dwflp); - dwfl_linux_kernel_report_modules(*dwflp); + dwfl_linux_kernel_report_kernel(self->dwfl); + dwfl_linux_kernel_report_modules(self->dwfl); - dbg = dwfl_addrdwarf(*dwflp, addr, bias); + self->dbg = dwfl_addrdwarf(self->dwfl, addr, &self->bias); /* Here, check whether we could get a real dwarf */ - if (!dbg) { + if (!self->dbg) { pr_debug("Failed to find kernel dwarf at %lx\n", (unsigned long)addr); - dwfl_end(*dwflp); - *dwflp = NULL; + dwfl_end(self->dwfl); + memset(self, 0, sizeof(*self)); + return -ENOENT; } - return dbg; + + return 0; } #else /* With older elfutils, this just support kernel module... */ -static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr __used, Dwfl **dwflp, - Dwarf_Addr *bias) +static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self, + Dwarf_Addr addr __used) { - int fd; const char *path = kernel_get_module_path("kernel"); if (!path) { pr_err("Failed to find vmlinux path\n"); - return NULL; + return -ENOENT; } pr_debug2("Use file %s for debuginfo\n", path); - fd = open(path, O_RDONLY); - if (fd < 0) - return NULL; - - return dwfl_init_offline_dwarf(fd, dwflp, bias); + return debuginfo__init_offline_dwarf(self, path); } #endif +struct debuginfo *debuginfo__new(const char *path) +{ + struct debuginfo *self = zalloc(sizeof(struct debuginfo)); + if (!self) + return NULL; + + if (debuginfo__init_offline_dwarf(self, path) < 0) { + free(self); + self = NULL; + } + + return self; +} + +struct debuginfo *debuginfo__new_online_kernel(unsigned long addr) +{ + struct debuginfo *self = zalloc(sizeof(struct debuginfo)); + if (!self) + return NULL; + + if (debuginfo__init_online_kernel_dwarf(self, (Dwarf_Addr)addr) < 0) { + free(self); + self = NULL; + } + + return self; +} + +void debuginfo__delete(struct debuginfo *self) +{ + if (self) { + if (self->dwfl) + dwfl_end(self->dwfl); + free(self); + } +} + /* * Probe finder related functions */ @@ -949,28 +986,18 @@ static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data) } /* Find probe points from debuginfo */ -static int find_probes(int fd, struct probe_finder *pf) +static int debuginfo__find_probes(struct debuginfo *self, + struct probe_finder *pf) { struct perf_probe_point *pp = &pf->pev->point; Dwarf_Off off, noff; size_t cuhl; Dwarf_Die *diep; - Dwarf *dbg = NULL; - Dwfl *dwfl; - Dwarf_Addr bias; /* Currently ignored */ int ret = 0; - dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias); - if (!dbg) { - pr_warning("No debug information found in the vmlinux - " - "please rebuild with CONFIG_DEBUG_INFO=y.\n"); - close(fd); /* Without dwfl_end(), fd isn't closed. */ - return -EBADF; - } - #if _ELFUTILS_PREREQ(0, 142) /* Get the call frame information from this dwarf */ - pf->cfi = dwarf_getcfi(dbg); + pf->cfi = dwarf_getcfi(self->dbg); #endif off = 0; @@ -989,7 +1016,8 @@ static int find_probes(int fd, struct probe_finder *pf) .data = pf, }; - dwarf_getpubnames(dbg, pubname_search_cb, &pubname_param, 0); + dwarf_getpubnames(self->dbg, pubname_search_cb, + &pubname_param, 0); if (pubname_param.found) { ret = probe_point_search_cb(&pf->sp_die, &probe_param); if (ret) @@ -998,9 +1026,9 @@ static int find_probes(int fd, struct probe_finder *pf) } /* Loop on CUs (Compilation Unit) */ - while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL)) { + while (!dwarf_nextcu(self->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) { /* Get the DIE(Debugging Information Entry) of this CU */ - diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die); + diep = dwarf_offdie(self->dbg, off + cuhl, &pf->cu_die); if (!diep) continue; @@ -1027,8 +1055,6 @@ static int find_probes(int fd, struct probe_finder *pf) found: line_list__free(&pf->lcache); - if (dwfl) - dwfl_end(dwfl); return ret; } @@ -1074,8 +1100,9 @@ static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf) } /* Find probe_trace_events specified by perf_probe_event from debuginfo */ -int find_probe_trace_events(int fd, struct perf_probe_event *pev, - struct probe_trace_event **tevs, int max_tevs) +int debuginfo__find_trace_events(struct debuginfo *self, + struct perf_probe_event *pev, + struct probe_trace_event **tevs, int max_tevs) { struct trace_event_finder tf = { .pf = {.pev = pev, .callback = add_probe_trace_event}, @@ -1090,7 +1117,7 @@ int find_probe_trace_events(int fd, struct perf_probe_event *pev, tf.tevs = *tevs; tf.ntevs = 0; - ret = find_probes(fd, &tf.pf); + ret = debuginfo__find_probes(self, &tf.pf); if (ret < 0) { free(*tevs); *tevs = NULL; @@ -1184,9 +1211,10 @@ out: } /* Find available variables at given probe point */ -int find_available_vars_at(int fd, struct perf_probe_event *pev, - struct variable_list **vls, int max_vls, - bool externs) +int debuginfo__find_available_vars_at(struct debuginfo *self, + struct perf_probe_event *pev, + struct variable_list **vls, + int max_vls, bool externs) { struct available_var_finder af = { .pf = {.pev = pev, .callback = add_available_vars}, @@ -1201,7 +1229,7 @@ int find_available_vars_at(int fd, struct perf_probe_event *pev, af.vls = *vls; af.nvls = 0; - ret = find_probes(fd, &af.pf); + ret = debuginfo__find_probes(self, &af.pf); if (ret < 0) { /* Free vlist for error */ while (af.nvls--) { @@ -1219,28 +1247,19 @@ int find_available_vars_at(int fd, struct perf_probe_event *pev, } /* Reverse search */ -int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt) +int debuginfo__find_probe_point(struct debuginfo *self, unsigned long addr, + struct perf_probe_point *ppt) { Dwarf_Die cudie, spdie, indie; - Dwarf *dbg = NULL; - Dwfl *dwfl = NULL; - Dwarf_Addr _addr, baseaddr, bias = 0; + Dwarf_Addr _addr, baseaddr; const char *fname = NULL, *func = NULL, *tmp; int baseline = 0, lineno = 0, ret = 0; - /* Open the live linux kernel */ - dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias); - if (!dbg) { - pr_warning("No debug information found in the vmlinux - " - "please rebuild with CONFIG_DEBUG_INFO=y.\n"); - ret = -EINVAL; - goto end; - } - /* Adjust address with bias */ - addr += bias; + addr += self->bias; + /* Find cu die */ - if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) { + if (!dwarf_addrdie(self->dbg, (Dwarf_Addr)addr - self->bias, &cudie)) { pr_warning("Failed to find debug information for address %lx\n", addr); ret = -EINVAL; @@ -1316,8 +1335,6 @@ post: } } end: - if (dwfl) - dwfl_end(dwfl); if (ret == 0 && (fname || func)) ret = 1; /* Found a point */ return ret; @@ -1427,26 +1444,15 @@ static int find_line_range_by_func(struct line_finder *lf) return param.retval; } -int find_line_range(int fd, struct line_range *lr) +int debuginfo__find_line_range(struct debuginfo *self, struct line_range *lr) { struct line_finder lf = {.lr = lr, .found = 0}; int ret = 0; Dwarf_Off off = 0, noff; size_t cuhl; Dwarf_Die *diep; - Dwarf *dbg = NULL; - Dwfl *dwfl; - Dwarf_Addr bias; /* Currently ignored */ const char *comp_dir; - dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias); - if (!dbg) { - pr_warning("No debug information found in the vmlinux - " - "please rebuild with CONFIG_DEBUG_INFO=y.\n"); - close(fd); /* Without dwfl_end(), fd isn't closed. */ - return -EBADF; - } - /* Fastpath: lookup by function name from .debug_pubnames section */ if (lr->function) { struct pubname_callback_param pubname_param = { @@ -1455,7 +1461,8 @@ int find_line_range(int fd, struct line_range *lr) struct dwarf_callback_param line_range_param = { .data = (void *)&lf, .retval = 0}; - dwarf_getpubnames(dbg, pubname_search_cb, &pubname_param, 0); + dwarf_getpubnames(self->dbg, pubname_search_cb, + &pubname_param, 0); if (pubname_param.found) { line_range_search_cb(&lf.sp_die, &line_range_param); if (lf.found) @@ -1465,11 +1472,12 @@ int find_line_range(int fd, struct line_range *lr) /* Loop on CUs (Compilation Unit) */ while (!lf.found && ret >= 0) { - if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0) + if (dwarf_nextcu(self->dbg, off, &noff, &cuhl, + NULL, NULL, NULL) != 0) break; /* Get the DIE(Debugging Information Entry) of this CU */ - diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die); + diep = dwarf_offdie(self->dbg, off + cuhl, &lf.cu_die); if (!diep) continue; @@ -1503,7 +1511,6 @@ found: } pr_debug("path: %s\n", lr->path); - 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 0f1ed3d25a20..c478b42a2473 100644 --- a/tools/perf/util/probe-finder.h +++ b/tools/perf/util/probe-finder.h @@ -16,23 +16,42 @@ static inline int is_c_varname(const char *name) } #ifdef DWARF_SUPPORT + +#include "dwarf-aux.h" + +/* TODO: export debuginfo data structure even if no dwarf support */ + +/* debug information structure */ +struct debuginfo { + Dwarf *dbg; + Dwfl *dwfl; + Dwarf_Addr bias; +}; + +extern struct debuginfo *debuginfo__new(const char *path); +extern struct debuginfo *debuginfo__new_online_kernel(unsigned long addr); +extern void debuginfo__delete(struct debuginfo *self); + /* Find probe_trace_events specified by perf_probe_event from debuginfo */ -extern int find_probe_trace_events(int fd, struct perf_probe_event *pev, - struct probe_trace_event **tevs, - int max_tevs); +extern int debuginfo__find_trace_events(struct debuginfo *self, + struct perf_probe_event *pev, + struct probe_trace_event **tevs, + int max_tevs); /* Find a perf_probe_point from debuginfo */ -extern int find_perf_probe_point(unsigned long addr, - struct perf_probe_point *ppt); +extern int debuginfo__find_probe_point(struct debuginfo *self, + unsigned long addr, + struct perf_probe_point *ppt); /* Find a line range */ -extern int find_line_range(int fd, struct line_range *lr); +extern int debuginfo__find_line_range(struct debuginfo *self, + struct line_range *lr); /* Find available variables */ -extern int find_available_vars_at(int fd, struct perf_probe_event *pev, - struct variable_list **vls, int max_points, - bool externs); -#include "dwarf-aux.h" +extern int debuginfo__find_available_vars_at(struct debuginfo *self, + struct perf_probe_event *pev, + struct variable_list **vls, + int max_points, bool externs); struct probe_finder { struct perf_probe_event *pev; /* Target probe event */