kernel/kallsyms.c: fix %pB when there's no symbol at the address

__sprint_symbol() should restore original address when kallsyms_lookup()
failed to find a symbol.  It's reported when dumpstack shows an address in
a dynamically allocated trampoline for ftrace.

  [ 1314.612287]  [<ffffffff81700312>] dump_stack+0x45/0x56
  [ 1314.612290]  [<ffffffff8125f5b0>] ? meminfo_proc_open+0x30/0x30
  [ 1314.612293]  [<ffffffffa080a494>] kpatch_ftrace_handler+0x14/0xf0 [kpatch]
  [ 1314.612306]  [<ffffffffa00160c4>] 0xffffffffa00160c3

You can see a difference in the hex address - c4 and c3.  Fix it.

Signed-off-by: Namhyung Kim <[email protected]>
Reported-by: Masami Hiramatsu <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Namhyung Kim 2014-08-08 14:19:41 -07:00 • committed by Linus Torvalds
commit b86280aa48

View file

@ -364,7 +364,7 @@ static int __sprint_symbol(char *buffer, unsigned long address,
address += symbol_offset;
name = kallsyms_lookup(address, &size, &offset, &modname, buffer);
if (!name)
return sprintf(buffer, "0x%lx", address);
return sprintf(buffer, "0x%lx", address - symbol_offset);
if (name != buffer)
strcpy(buffer, name);