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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2017-11-16 14:54:04 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2017-11-20 08:51:01 +0100 |
| commit | 3241d3eb7d9bb7a134bedf49db196cf98b58834d (patch) | |
| tree | 3cff9d30519f530838e1ee5a2452908d4b508b62 /arch/s390 | |
| parent | 38389ec84e835fa31a59b7dabb18343106a6d0d5 (diff) | |
| download | lwn-3241d3eb7d9bb7a134bedf49db196cf98b58834d.tar.gz lwn-3241d3eb7d9bb7a134bedf49db196cf98b58834d.zip | |
s390: rework __switch_to() to allow larger task_struct offsets
If GCC_PLUGIN_RANDSTRUCT is enabled the members of task_struct will be
shuffled around. The offsets of the "pid" and "stack" members within
task_struct may not necessarily fit into 12 bits anymore, which causes
compile errors within __switch_to, since instructions are used, which
only have a 12 bit displacement field.
Therefore rework __switch_to, to allow for larger offsets.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/kernel/entry.S | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index a316cd6999ad..9e5f6cd8e4c2 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -180,18 +180,17 @@ _PIF_WORK = (_PIF_PER_TRAP | _PIF_SYSCALL_RESTART) */ ENTRY(__switch_to) stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task - lgr %r1,%r2 - aghi %r1,__TASK_thread # thread_struct of prev task - lg %r5,__TASK_stack(%r3) # start of kernel stack of next - stg %r15,__THREAD_ksp(%r1) # store kernel stack of prev - lgr %r1,%r3 - aghi %r1,__TASK_thread # thread_struct of next task + lghi %r4,__TASK_stack + lghi %r1,__TASK_thread + lg %r5,0(%r4,%r3) # start of kernel stack of next + stg %r15,__THREAD_ksp(%r1,%r2) # store kernel stack of prev lgr %r15,%r5 aghi %r15,STACK_INIT # end of kernel stack of next stg %r3,__LC_CURRENT # store task struct of next stg %r15,__LC_KERNEL_STACK # store end of kernel stack - lg %r15,__THREAD_ksp(%r1) # load kernel stack of next - mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next + lg %r15,__THREAD_ksp(%r1,%r3) # load kernel stack of next + aghi %r3,__TASK_pid + mvc __LC_CURRENT_PID(4,%r0),0(%r3) # store pid of next lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPP bzr %r14 |