Commit ff741783 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt

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: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20110627072739.6528.12438.stgit@fedora15Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent e0d153c6
......@@ -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 @@ int show_line_range(struct line_range *lr, const char *module)
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;
}
......
......@@ -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)
......@@ -174,53 +182,82 @@ 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 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;
return dwfl_init_offline_dwarf(fd, dwflp, bias);
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);
}
}
#endif
/*
* 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 @@ static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
}
/* 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 @@ int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
}
}
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 @@ int find_line_range(int fd, struct line_range *lr)
}
pr_debug("path: %s\n", lr->path);
dwfl_end(dwfl);
return (ret < 0) ? ret : lf.found;
}
......@@ -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 */
......
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