Commit 176b1803 authored by Martin Schwidefsky's avatar Martin Schwidefsky Committed by Martin Schwidefsky

[S390] fix io_return critical section cleanup

If a machine check interrupts the io interrupt handler on one of the
instructions between io_return and io_leave the critical section
cleanup code will move the return psw to io_work_loop. By doing that
the switch from the asynchronous interrupt stack to the process stack
is skipped. If e.g. TIF_NEED_RESCHED is set things break because
the scheduler is called with the asynchronous interrupts stack.
Moving the psw back to io_return instead fixes the problem.
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 35ac734f
...@@ -964,7 +964,7 @@ cleanup_critical: ...@@ -964,7 +964,7 @@ cleanup_critical:
clc 4(4,%r12),BASED(cleanup_table_io_work_loop) clc 4(4,%r12),BASED(cleanup_table_io_work_loop)
bl BASED(0f) bl BASED(0f)
clc 4(4,%r12),BASED(cleanup_table_io_work_loop+4) clc 4(4,%r12),BASED(cleanup_table_io_work_loop+4)
bl BASED(cleanup_io_return) bl BASED(cleanup_io_work_loop)
0: 0:
br %r14 br %r14
...@@ -1038,6 +1038,12 @@ cleanup_sysc_leave_insn: ...@@ -1038,6 +1038,12 @@ cleanup_sysc_leave_insn:
.long sysc_done - 8 + 0x80000000 .long sysc_done - 8 + 0x80000000
cleanup_io_return: cleanup_io_return:
mvc __LC_RETURN_PSW(4),0(%r12)
mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_io_return)
la %r12,__LC_RETURN_PSW
br %r14
cleanup_io_work_loop:
mvc __LC_RETURN_PSW(4),0(%r12) mvc __LC_RETURN_PSW(4),0(%r12)
mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_io_work_loop) mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_io_work_loop)
la %r12,__LC_RETURN_PSW la %r12,__LC_RETURN_PSW
......
...@@ -946,7 +946,7 @@ cleanup_critical: ...@@ -946,7 +946,7 @@ cleanup_critical:
clc 8(8,%r12),BASED(cleanup_table_io_work_loop) clc 8(8,%r12),BASED(cleanup_table_io_work_loop)
jl 0f jl 0f
clc 8(8,%r12),BASED(cleanup_table_io_work_loop+8) clc 8(8,%r12),BASED(cleanup_table_io_work_loop+8)
jl cleanup_io_return jl cleanup_io_work_loop
0: 0:
br %r14 br %r14
...@@ -1020,6 +1020,12 @@ cleanup_sysc_leave_insn: ...@@ -1020,6 +1020,12 @@ cleanup_sysc_leave_insn:
.quad sysc_done - 16 .quad sysc_done - 16
cleanup_io_return: cleanup_io_return:
mvc __LC_RETURN_PSW(8),0(%r12)
mvc __LC_RETURN_PSW+8(8),BASED(cleanup_table_io_return)
la %r12,__LC_RETURN_PSW
br %r14
cleanup_io_work_loop:
mvc __LC_RETURN_PSW(8),0(%r12) mvc __LC_RETURN_PSW(8),0(%r12)
mvc __LC_RETURN_PSW+8(8),BASED(cleanup_table_io_work_loop) mvc __LC_RETURN_PSW+8(8),BASED(cleanup_table_io_work_loop)
la %r12,__LC_RETURN_PSW la %r12,__LC_RETURN_PSW
......
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