Commit a9ece53c authored by Paul Mundt's avatar Paul Mundt Committed by Linus Torvalds

kallsyms: fix segfault in prefix_underscores_count()

Commit b478b782 "kallsyms, tracing: output
more proper symbol name" introduces a "bugfix" that introduces a segfault
in kallsyms in my configurations.

The cause is the introduction of prefix_underscores_count() which attempts
to count underscores, even in symbols that do not have them.  As a result,
it just uselessly runs past the end of the buffer until it crashes:

  CC      init/version.o
  LD      init/built-in.o
  LD      .tmp_vmlinux1
  KSYM    .tmp_kallsyms1.S
/bin/sh: line 1: 16934 Done                    sh-linux-gnu-nm -n .tmp_vmlinux1
     16935 Segmentation fault      | scripts/kallsyms > .tmp_kallsyms1.S
make: *** [.tmp_kallsyms1.S] Error 139

This simplifies the logic and just does a straightforward count.
Signed-off-by: default avatarPaul Mundt <>
Reviewed-by: default avatarLi Zefan <>
Cc: Lai Jiangshan <>
Cc: Sam Ravnborg <>
Cc: Paulo Marques <>
Cc: Ingo Molnar <>
Cc: <>		[2.6.30.x, 2.6.31.x]
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 1f10206c
......@@ -585,7 +585,7 @@ static int prefix_underscores_count(const char *str)
const char *tail = str;
while (*tail != '_')
while (*tail == '_')
return tail - str;
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