[PATCH v3 6/7] kallsyms/ftrace: Set module buildid in ftrace_mod_address_lookup()

[Petr Mladek]

__sprint_symbol() might access an invalid pointer when
kallsyms_lookup_buildid() returns a symbol found by
ftrace_mod_address_lookup().

The ftrace lookup function must set both @modname and @modbuildid
the same way as module_address_lookup().

Fixes: 9294523e3768 ("module: add printk formats to add module build ID to 
stacktraces")
Reviewed-by: Aaron Tomlin <atom...@atomlin.com>
Acked-by: Steven Rostedt (Google) <rost...@goodmis.org>
Signed-off-by: Petr Mladek <pmla...@suse.com>
---
 include/linux/ftrace.h | 6 ++++--
 kernel/kallsyms.c      | 4 ++--
 kernel/trace/ftrace.c  | 5 ++++-
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 07f8c309e432..9cc60e2506af 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -87,11 +87,13 @@ struct ftrace_hash;
        defined(CONFIG_DYNAMIC_FTRACE)
 int
 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
-                  unsigned long *off, char **modname, char *sym);
+                         unsigned long *off, char **modname,
+                         const unsigned char **modbuildid, char *sym);
 #else
 static inline int
 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
-                  unsigned long *off, char **modname, char *sym)
+                         unsigned long *off, char **modname,
+                         const unsigned char **modbuildid, char *sym)
 {
        return 0;
 }
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 97b92fc8871d..5bc1646f8639 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -386,8 +386,8 @@ static int kallsyms_lookup_buildid(unsigned long addr,
                ret = bpf_address_lookup(addr, symbolsize, offset, namebuf);
 
        if (!ret)
-               ret = ftrace_mod_address_lookup(addr, symbolsize,
-                                               offset, modname, namebuf);
+               ret = ftrace_mod_address_lookup(addr, symbolsize, offset,
+                                               modname, modbuildid, namebuf);
 
        return ret;
 }
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 59cfacb8a5bb..d0001dffd98a 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -7708,7 +7708,8 @@ ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
 
 int
 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
-                  unsigned long *off, char **modname, char *sym)
+                         unsigned long *off, char **modname,
+                         const unsigned char **modbuildid, char *sym)
 {
        struct ftrace_mod_map *mod_map;
        int ret = 0;
@@ -7720,6 +7721,8 @@ ftrace_mod_address_lookup(unsigned long addr, unsigned 
long *size,
                if (ret) {
                        if (modname)
                                *modname = mod_map->mod->name;
+                       if (modbuildid)
+                               *modbuildid = module_buildid(mod_map->mod);
                        break;
                }
        }
-- 
2.52.0