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Commit c58d92b2 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
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[S390] Remove initial kernel stack backchain initialization. 



Early init code clears the backchain of the initial kernel stack frame.
This is not necessary since it is pre initialized with zeros. Plus it
was broken on 64 bit since it cleared only four of eight bytes.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 64253acb

arch/s390/kernel/head31.S

+0 −1
Original line number Diff line number Diff line
@@ -29,7 +29,6 @@ startup_continue: 
	ahi	%r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union+THREAD_SIZE

	st	%r15,__LC_KERNEL_STACK	# set end of kernel stack

	ahi	%r15,-96

	xc	__SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain

#

# Save ipl parameters, clear bss memory, initialize storage key for kernel pages,

# and create a kernel NSS if the SAVESYS= parm is defined

arch/s390/kernel/head64.S

+0 −1
Original line number Diff line number Diff line
@@ -96,7 +96,6 @@ startup_continue: 
	aghi	%r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE

	stg	%r15,__LC_KERNEL_STACK	# set end of kernel stack

	aghi	%r15,-160

	xc	__SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain

#

# Save ipl parameters, clear bss memory, initialize storage key for kernel pages,

# and create a kernel NSS if the SAVESYS= parm is defined