[PATCH] lockdep: special s390 print_symbol() version

Have a special version of print_symbol() for s390 which clears the most
significant bit of addr before calling __print_symbol().  This seems to be
better than checking/changing each place in the kernel that saves an
instruction pointer.

Without this the output would look like:

hardirqs last  enabled at (30907): [<80018c6a>] 0x80018c6a
hardirqs last disabled at (30908): [<8001e48c>] 0x8001e48c
softirqs last  enabled at (30904): [<8001dc96>] 0x8001dc96
softirqs last disabled at (30897): [<8001dc50>] 0x8001dc50

instead of this:

hardirqs last  enabled at (19421): [<80018c72>] cpu_idle+0x176/0x1c4
hardirqs last disabled at (19422): [<8001e494>] io_no_vtime+0xa/0x1a
softirqs last  enabled at (19418): [<8001dc9e>] do_softirq+0xa6/0xe8
softirqs last disabled at (19411): [<8001dc58>] do_softirq+0x60/0xe8

Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 5 deletions

diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index 54e2549f96ba..ad71ac053d6e 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -57,10 +57,11 @@ do {						\
 #define print_fn_descriptor_symbol(fmt, addr) print_symbol(fmt, addr)
 #endif
 
-#define print_symbol(fmt, addr)                 \
-do {                                            \
-        __check_printsym_format(fmt, "");       \
-        __print_symbol(fmt, addr);              \
-} while(0)
+static inline void print_symbol(const char *fmt, unsigned long addr)
+{
+        __check_printsym_format(fmt, "");
+        __print_symbol(fmt, (unsigned long)
+                       __builtin_extract_return_addr((void *)addr));
+}
 
 #endif /*_LINUX_KALLSYMS_H*/