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perf probe: Allow placing uprobes in alternate namespaces.

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Teaches perf how to place a uprobe on a file that's in a different mount
namespace.  The user must add the probe using the --target-ns argument
to perf probe.  Once it has been placed, it may be recorded against
without further namespace-specific commands.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
[ PPC build fixed by Ravi: ]
Link: http://lkml.kernel.org/r/1500287542-6219-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
[ Fix !HAVE_DWARF_SUPPORT build ]
Link: http://lkml.kernel.org/r/1499305693-1599-4-git-send-email-kjlx@templeofstupid.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Krister Johansen
2017-07-05 18:48:10 -07:00
committed by Arnaldo Carvalho de Melo
parent bf2e710b3c
commit 544abd44c7
7 changed files with 125 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

80
tools/perf/util/probe-event.c
View File

@@ -184,13 +184,19 @@ static struct map *kernel_get_module_map(const char *module)
return NULL;
}
struct map *get_target_map(const char *target, bool user)
struct map *get_target_map(const char *target, struct nsinfo *nsi, bool user)
{
/* Init maps of given executable or kernel */
if (user)
return dso__new_map(target);
else
if (user) {
struct map *map;
map = dso__new_map(target);
if (map && map->dso)
map->dso->nsinfo = nsinfo__get(nsi);
return map;
} else {
return kernel_get_module_map(target);
}
}
static int convert_exec_to_group(const char *exec, char **result)
@@ -366,7 +372,8 @@ found:
static int find_alternative_probe_point(struct debuginfo *dinfo,
struct perf_probe_point *pp,
struct perf_probe_point *result,
const char *target, bool uprobes)
const char *target, struct nsinfo *nsi,
bool uprobes)
{
struct map *map = NULL;
struct symbol *sym;
@@ -377,7 +384,7 @@ static int find_alternative_probe_point(struct debuginfo *dinfo,
if (!pp->function || pp->file)
return -ENOTSUP;
map = get_target_map(target, uprobes);
map = get_target_map(target, nsi, uprobes);
if (!map)
return -EINVAL;
@@ -421,8 +428,8 @@ static int get_alternative_probe_event(struct debuginfo *dinfo,
memcpy(tmp, &pev->point, sizeof(*tmp));
memset(&pev->point, 0, sizeof(pev->point));
ret = find_alternative_probe_point(dinfo, tmp, &pev->point,
pev->target, pev->uprobes);
ret = find_alternative_probe_point(dinfo, tmp, &pev->point, pev->target,
pev->nsi, pev->uprobes);
if (ret < 0)
memcpy(&pev->point, tmp, sizeof(*tmp));
@@ -444,7 +451,7 @@ static int get_alternative_line_range(struct debuginfo *dinfo,
if (lr->end != INT_MAX)
len = lr->end - lr->start;
ret = find_alternative_probe_point(dinfo, &pp, &result,
target, user);
target, NULL, user);
if (!ret) {
lr->function = result.function;
lr->file = result.file;
@@ -457,12 +464,14 @@ static int get_alternative_line_range(struct debuginfo *dinfo,
}
/* Open new debuginfo of given module */
static struct debuginfo *open_debuginfo(const char *module, bool silent)
static struct debuginfo *open_debuginfo(const char *module, struct nsinfo *nsi,
bool silent)
{
const char *path = module;
char reason[STRERR_BUFSIZE];
struct debuginfo *ret = NULL;
struct dso *dso = NULL;
struct nscookie nsc;
int err;
if (!module || !strchr(module, '/')) {
@@ -480,6 +489,7 @@ static struct debuginfo *open_debuginfo(const char *module, bool silent)
}
path = dso->long_name;
}
nsinfo__mountns_enter(nsi, &nsc);
ret = debuginfo__new(path);
if (!ret && !silent) {
pr_warning("The %s file has no debug information.\n", path);
@@ -489,6 +499,7 @@ static struct debuginfo *open_debuginfo(const char *module, bool silent)
pr_warning("Rebuild with -g, ");
pr_warning("or install an appropriate debuginfo package.\n");
}
nsinfo__mountns_exit(&nsc);
return ret;
}
@@ -516,7 +527,7 @@ static struct debuginfo *debuginfo_cache__open(const char *module, bool silent)
goto out;
}
debuginfo_cache = open_debuginfo(module, silent);
debuginfo_cache = open_debuginfo(module, NULL, silent);
if (!debuginfo_cache)
zfree(&debuginfo_cache_path);
out:
@@ -531,14 +542,18 @@ static void debuginfo_cache__exit(void)
}
static int get_text_start_address(const char *exec, unsigned long *address)
static int get_text_start_address(const char *exec, unsigned long *address,
struct nsinfo *nsi)
{
Elf *elf;
GElf_Ehdr ehdr;
GElf_Shdr shdr;
int fd, ret = -ENOENT;
struct nscookie nsc;
nsinfo__mountns_enter(nsi, &nsc);
fd = open(exec, O_RDONLY);
nsinfo__mountns_exit(&nsc);
if (fd < 0)
return -errno;
@@ -582,7 +597,7 @@ static int find_perf_probe_point_from_dwarf(struct probe_trace_point *tp,
ret = -EINVAL;
goto error;
}
ret = get_text_start_address(tp->module, &stext);
ret = get_text_start_address(tp->module, &stext, NULL);
if (ret < 0)
goto error;
addr += stext;
@@ -659,7 +674,7 @@ post_process_offline_probe_trace_events(struct probe_trace_event *tevs,
/* Prepare a map for offline binary */
map = dso__new_map(pathname);
if (!map || get_text_start_address(pathname, &stext) < 0) {
if (!map || get_text_start_address(pathname, &stext, NULL) < 0) {
pr_warning("Failed to get ELF symbols for %s\n", pathname);
return -EINVAL;
}
@@ -676,7 +691,8 @@ post_process_offline_probe_trace_events(struct probe_trace_event *tevs,
}
static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,
int ntevs, const char *exec)
int ntevs, const char *exec,
struct nsinfo *nsi)
{
int i, ret = 0;
unsigned long stext = 0;
@@ -684,7 +700,7 @@ static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,
if (!exec)
return 0;
ret = get_text_start_address(exec, &stext);
ret = get_text_start_address(exec, &stext, nsi);
if (ret < 0)
return ret;
@@ -715,7 +731,7 @@ post_process_module_probe_trace_events(struct probe_trace_event *tevs,
if (!module)
return 0;
map = get_target_map(module, false);
map = get_target_map(module, NULL, false);
if (!map || debuginfo__get_text_offset(dinfo, &text_offs, true) < 0) {
pr_warning("Failed to get ELF symbols for %s\n", module);
return -EINVAL;
@@ -802,7 +818,8 @@ static int post_process_probe_trace_events(struct perf_probe_event *pev,
int ret;
if (uprobe)
ret = add_exec_to_probe_trace_events(tevs, ntevs, module);
ret = add_exec_to_probe_trace_events(tevs, ntevs, module,
pev->nsi);
else if (module)
/* Currently ref_reloc_sym based probe is not for drivers */
ret = post_process_module_probe_trace_events(tevs, ntevs,
@@ -825,7 +842,7 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
struct debuginfo *dinfo;
int ntevs, ret = 0;
dinfo = open_debuginfo(pev->target, !need_dwarf);
dinfo = open_debuginfo(pev->target, pev->nsi, !need_dwarf);
if (!dinfo) {
if (need_dwarf)
return -ENOENT;
@@ -945,7 +962,7 @@ static int __show_line_range(struct line_range *lr, const char *module,
char sbuf[STRERR_BUFSIZE];
/* Search a line range */
dinfo = open_debuginfo(module, false);
dinfo = open_debuginfo(module, NULL, false);
if (!dinfo)
return -ENOENT;
@@ -1021,14 +1038,18 @@ end:
return ret;
}
int show_line_range(struct line_range *lr, const char *module, bool user)
int show_line_range(struct line_range *lr, const char *module,
struct nsinfo *nsi, bool user)
{
int ret;
struct nscookie nsc;
ret = init_probe_symbol_maps(user);
if (ret < 0)
return ret;
nsinfo__mountns_enter(nsi, &nsc);
ret = __show_line_range(lr, module, user);
nsinfo__mountns_exit(&nsc);
exit_probe_symbol_maps();
return ret;
@@ -1111,7 +1132,7 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs,
if (ret < 0)
return ret;
dinfo = open_debuginfo(pevs->target, false);
dinfo = open_debuginfo(pevs->target, pevs->nsi, false);
if (!dinfo) {
ret = -ENOENT;
goto out;
@@ -1155,6 +1176,7 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
int show_line_range(struct line_range *lr __maybe_unused,
const char *module __maybe_unused,
struct nsinfo *nsi __maybe_unused,
bool user __maybe_unused)
{
pr_warning("Debuginfo-analysis is not supported.\n");
@@ -2703,6 +2725,7 @@ static int __add_probe_trace_events(struct perf_probe_event *pev,
struct probe_trace_event *tev = NULL;
struct probe_cache *cache = NULL;
struct strlist *namelist[2] = {NULL, NULL};
struct nscookie nsc;
up = pev->uprobes ? 1 : 0;
fd[up] = __open_probe_file_and_namelist(up, &namelist[up]);
@@ -2729,7 +2752,9 @@ static int __add_probe_trace_events(struct perf_probe_event *pev,
if (ret < 0)
break;
nsinfo__mountns_enter(pev->nsi, &nsc);
ret = probe_file__add_event(fd[up], tev);
nsinfo__mountns_exit(&nsc);
if (ret < 0)
break;
@@ -2805,7 +2830,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev,
int ret, i, j, skipped = 0;
char *mod_name;
map = get_target_map(pev->target, pev->uprobes);
map = get_target_map(pev->target, pev->nsi, pev->uprobes);
if (!map) {
ret = -EINVAL;
goto out;
@@ -3345,13 +3370,16 @@ int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs)
void cleanup_perf_probe_events(struct perf_probe_event *pevs, int npevs)
{
int i, j;
struct perf_probe_event *pev;
/* Loop 3: cleanup and free trace events */
for (i = 0; i < npevs; i++) {
pev = &pevs[i];
for (j = 0; j < pevs[i].ntevs; j++)
clear_probe_trace_event(&pevs[i].tevs[j]);
zfree(&pevs[i].tevs);
pevs[i].ntevs = 0;
nsinfo__zput(pev->nsi);
clear_perf_probe_event(&pevs[i]);
}
}
@@ -3409,8 +3437,8 @@ out:
return ret;
}
int show_available_funcs(const char *target, struct strfilter *_filter,
bool user)
int show_available_funcs(const char *target, struct nsinfo *nsi,
struct strfilter *_filter, bool user)
{
struct rb_node *nd;
struct map *map;
@@ -3421,7 +3449,7 @@ int show_available_funcs(const char *target, struct strfilter *_filter,
return ret;
/* Get a symbol map */
map = get_target_map(target, user);
map = get_target_map(target, nsi, user);
if (!map) {
pr_err("Failed to get a map for %s\n", (target) ? : "kernel");
return -EINVAL;