Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

 * It was possible to use an uninitialized buffer when reading
   kernel modules information and checking if the file was a
   /proc/sys/kernel/kptr_restrict'ed one, fix for this from
   Adrian Hunter.

 * The libbfd demangler doesn't handle cloned functions (e.g. symbol.clone.NUM),
   feed it unsuffixed symbol names, workaround from Andi Kleen.

 * Fix segfault in 'perf trace' when processing perf.data files with PERF_RECORD_MMAP2
   records, recently added but not handled in this tool, from David Ahern.

 * Fix libdl related build in old systems like Fedora 12, from David Ahern.

 * Make 'perf kmem' work again on non NUMA machines, fix from Jiri Olsa.

 * Fix probing symbols with optimization suffix in 'perf probe' where some
   operations that are entirely user level and involves vmlinux/DWARF were working
   but when the symbol name was fed to the kprobes tracer, the in kernel code
   would use /proc/kallsyms where the name had the suffix, from Masami Hiramatsu.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

4 files changed, 71 insertions, 38 deletions

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 933d14f287ca..6188d2876a71 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -792,7 +792,7 @@ static int machine__create_modules(struct machine *machine)
                 modules = path;
         }
 
-        if (symbol__restricted_filename(path, "/proc/modules"))
+        if (symbol__restricted_filename(modules, "/proc/modules"))
                 return -1;
 
         file = fopen(modules, "r");
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 20c7299a9d4e..371476cb8ddc 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -118,7 +118,6 @@ static const Dwfl_Callbacks offline_callbacks = {
 static int debuginfo__init_offline_dwarf(struct debuginfo *self,
                                          const char *path)
 {
-        Dwfl_Module *mod;
         int fd;
 
         fd = open(path, O_RDONLY);
@@ -129,11 +128,11 @@ static int debuginfo__init_offline_dwarf(struct debuginfo *self,
         if (!self->dwfl)
                 goto error;
 
-        mod = dwfl_report_offline(self->dwfl, "", "", fd);
-        if (!mod)
+        self->mod = dwfl_report_offline(self->dwfl, "", "", fd);
+        if (!self->mod)
                 goto error;
 
-        self->dbg = dwfl_module_getdwarf(mod, &self->bias);
+        self->dbg = dwfl_module_getdwarf(self->mod, &self->bias);
         if (!self->dbg)
                 goto error;
 
@@ -676,37 +675,42 @@ static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
 }
 
 /* Convert subprogram DIE to trace point */
-static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
-                                  bool retprobe, struct probe_trace_point *tp)
+static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
+                                  Dwarf_Addr paddr, bool retprobe,
+                                  struct probe_trace_point *tp)
 {
         Dwarf_Addr eaddr, highaddr;
-        const char *name;
-
-        /* Copy the name of probe point */
-        name = dwarf_diename(sp_die);
-        if (name) {
-                if (dwarf_entrypc(sp_die, &eaddr) != 0) {
-                        pr_warning("Failed to get entry address of %s\n",
-                                   dwarf_diename(sp_die));
-                        return -ENOENT;
-                }
-                if (dwarf_highpc(sp_die, &highaddr) != 0) {
-                        pr_warning("Failed to get end address of %s\n",
-                                   dwarf_diename(sp_die));
-                        return -ENOENT;
-                }
-                if (paddr > highaddr) {
-                        pr_warning("Offset specified is greater than size of %s\n",
-                                   dwarf_diename(sp_die));
-                        return -EINVAL;
-                }
-                tp->symbol = strdup(name);
-                if (tp->symbol == NULL)
-                        return -ENOMEM;
-                tp->offset = (unsigned long)(paddr - eaddr);
-        } else
-                /* This function has no name. */
-                tp->offset = (unsigned long)paddr;
+        GElf_Sym sym;
+        const char *symbol;
+
+        /* Verify the address is correct */
+        if (dwarf_entrypc(sp_die, &eaddr) != 0) {
+                pr_warning("Failed to get entry address of %s\n",
+                           dwarf_diename(sp_die));
+                return -ENOENT;
+        }
+        if (dwarf_highpc(sp_die, &highaddr) != 0) {
+                pr_warning("Failed to get end address of %s\n",
+                           dwarf_diename(sp_die));
+                return -ENOENT;
+        }
+        if (paddr > highaddr) {
+                pr_warning("Offset specified is greater than size of %s\n",
+                           dwarf_diename(sp_die));
+                return -EINVAL;
+        }
+
+        /* Get an appropriate symbol from symtab */
+        symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
+        if (!symbol) {
+                pr_warning("Failed to find symbol at 0x%lx\n",
+                           (unsigned long)paddr);
+                return -ENOENT;
+        }
+        tp->offset = (unsigned long)(paddr - sym.st_value);
+        tp->symbol = strdup(symbol);
+        if (!tp->symbol)
+                return -ENOMEM;
 
         /* Return probe must be on the head of a subprogram */
         if (retprobe) {
@@ -1149,7 +1153,7 @@ static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
         tev = &tf->tevs[tf->ntevs++];
 
         /* Trace point should be converted from subprogram DIE */
-        ret = convert_to_trace_point(&pf->sp_die, pf->addr,
+        ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
                                      pf->pev->point.retprobe, &tev->point);
         if (ret < 0)
                 return ret;
@@ -1181,7 +1185,7 @@ int debuginfo__find_trace_events(struct debuginfo *self,
 {
         struct trace_event_finder tf = {
                         .pf = {.pev = pev, .callback = add_probe_trace_event},
-                        .max_tevs = max_tevs};
+                        .mod = self->mod, .max_tevs = max_tevs};
         int ret;
 
         /* Allocate result tevs array */
@@ -1250,7 +1254,7 @@ static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
         vl = &af->vls[af->nvls++];
 
         /* Trace point should be converted from subprogram DIE */
-        ret = convert_to_trace_point(&pf->sp_die, pf->addr,
+        ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
                                      pf->pev->point.retprobe, &vl->point);
         if (ret < 0)
                 return ret;
@@ -1289,6 +1293,7 @@ int debuginfo__find_available_vars_at(struct debuginfo *self,
 {
         struct available_var_finder af = {
                         .pf = {.pev = pev, .callback = add_available_vars},
+                        .mod = self->mod,
                         .max_vls = max_vls, .externs = externs};
         int ret;
 
diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
index 17e94d0c36f9..3b7d63018960 100644
--- a/tools/perf/util/probe-finder.h
+++ b/tools/perf/util/probe-finder.h
@@ -23,6 +23,7 @@ static inline int is_c_varname(const char *name)
 /* debug information structure */
 struct debuginfo {
         Dwarf           *dbg;
+        Dwfl_Module     *mod;
         Dwfl            *dwfl;
         Dwarf_Addr      bias;
 };
@@ -77,6 +78,7 @@ struct probe_finder {
 
 struct trace_event_finder {
         struct probe_finder     pf;
+        Dwfl_Module             *mod;           /* For solving symbols */
         struct probe_trace_event *tevs;         /* Found trace events */
         int                     ntevs;          /* Number of trace events */
         int                     max_tevs;       /* Max number of trace events */
@@ -84,6 +86,7 @@ struct trace_event_finder {
 
 struct available_var_finder {
         struct probe_finder     pf;
+        Dwfl_Module             *mod;           /* For solving symbols */
         struct variable_list    *vls;           /* Found variable lists */
         int                     nvls;           /* Number of variable lists */
         int                     max_vls;        /* Max no. of variable lists */
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index a9c829be5216..d2a888e2e058 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -928,8 +928,33 @@ int dso__load_sym(struct dso *dso, struct map *map,
                  * to it...
                  */
                 if (symbol_conf.demangle) {
-                        demangled = bfd_demangle(NULL, elf_name,
+                        /*
+                         * The demangler doesn't deal with cloned functions.
+                         * XXXX.clone.NUM or similar
+                         * Strip the dot part and readd it later.
+                         */
+                        char *p = (char *)elf_name, *dot;
+                        dot = strchr(elf_name, '.');
+                        if (dot) {
+                                p = strdup(elf_name);
+                                if (!p)
+                                        goto new_symbol;
+                                dot = strchr(p, '.');
+                                *dot = 0;
+                        }
+
+                        demangled = bfd_demangle(NULL, p,
                                                  DMGL_PARAMS | DMGL_ANSI);
+                        if (dot)
+                                *dot = '.';
+                        if (demangled && dot) {
+                                demangled = realloc(demangled, strlen(demangled) + strlen(dot) + 1);
+                                if (!demangled)
+                                        goto new_symbol;
+                                strcpy(demangled + (dot - p), dot);
+                        }
+                        if (p != elf_name)
+                                free(p);
                         if (demangled != NULL)
                                 elf_name = demangled;
                 }