Commit 46210c44 authored Jun 30, 2016 by Heiko Carstens Committed by Martin Schwidefsky Jul 04, 2016

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>

parent 10f4954a

arch/s390/kernel/entry.S

+10 −0

Original line number	Diff line number	Diff line
		@@ -163,6 +163,16 @@ _PIF_WORK = (_PIF_PER_TRAP)
		.endm

		.section .kprobes.text, "ax"
		.Ldummy:
		/*
		* 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