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s390: use proper expoline sections for .dma code

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The text_dma.S code uses its own macro to generate an inline version of an
expoline. To make it easier to identify all expolines in the kernel use a
thunk and a branch to the thunk just like the rest of the kernel code does
it.

The name of the text_dma.S expoline thunk is __dma__s390_indirect_jump_r14
and the section is named .dma.text.__s390_indirect_jump_r14.

This will be needed for the objtool support.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2019-04-12 08:57:34 +02:00
parent 40a3abf751
commit bf72630130
1 changed files with 15 additions and 4 deletions
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19
arch/s390/boot/text_dma.S
View File

@ -9,6 +9,16 @@
#include <asm/errno.h>
#include <asm/sigp.h>
#ifdef CC_USING_EXPOLINE
.pushsection .dma.text.__s390_indirect_jump_r14,"axG"
__dma__s390_indirect_jump_r14:
larl %r1,0f
ex 0,0(%r1)
j .
0: br %r14
.popsection
#endif
.section .dma.text,"ax"
/*
* Simplified version of expoline thunk. The normal thunks can not be used here,
@ -17,10 +27,11 @@
* affects a few functions that are not performance-relevant.
*/
.macro BR_EX_DMA_r14
larl %r1,0f
ex 0,0(%r1)
j .
0: br %r14
#ifdef CC_USING_EXPOLINE
jg __dma__s390_indirect_jump_r14
#else
br %r14
#endif
.endm
/*