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authorHeiko Carstens <heiko.carstens@de.ibm.com>2016-06-30 12:40:25 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2016-07-04 09:25:22 +0200
commit46210c440c7b2d32a8ee4e1f0248d0a0b4ad9fa5 (patch)
parents390/cpuinfo: show maximum thread id (diff)
s390: have unique symbol for __switch_to address
After linking there are several symbols for the same address that the __switch_to symbol points to. E.g.: 000000000089b9c0 T __kprobes_text_start 000000000089b9c0 T __lock_text_end 000000000089b9c0 T __lock_text_start 000000000089b9c0 T __sched_text_end 000000000089b9c0 T __switch_to When disassembling with "objdump -d" this results in a missing __switch_to function. It would be named __kprobes_text_start instead. To unconfuse objdump add a nop in front of the kprobes text section. That way __switch_to appears again. Obviously this solution is sort of a hack, since it also depends on link order if this works or not. However it is the best I can come up with for now. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 9a9a35657860..c51650a1ed16 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -163,6 +163,16 @@ _PIF_WORK = (_PIF_PER_TRAP)
.section .kprobes.text, "ax"
+ /*
+ * This nop exists only in order to avoid that __switch_to starts at
+ * the beginning of the kprobes text section. In that case we would
+ * have several symbols at the same address. E.g. objdump would take
+ * an arbitrary symbol name when disassembling this code.
+ * With the added nop in between the __switch_to symbol is unique
+ * again.
+ */
+ nop 0
* Scheduler resume function, called by switch_to