From: Namhyung Kim <namhyung@kernel.org>
Date: Fri, 8 Aug 2014 21:19:41 +0000 (-0700)
Subject: kernel/kallsyms.c: fix %pB when there's no symbol at the address
X-Git-Tag: firefly_0821_release~176^2~3441^2~181
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b86280aa48b67c8119ed8f6c6bebd8c0af13a269;p=firefly-linux-kernel-4.4.55.git

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 <namhyung@kernel.org>
Reported-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index cb0cf37dac3a..ae5167087845 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -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);