Eric Lee / linux-smarc-t335x-v3.2

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Commit 176b1803ce4690d0dd94e16f118dbd14af045034

Authored by Martin Schwidefsky
Committed by Martin Schwidefsky
1 parent 35ac734f72
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

[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: Martin Schwidefsky <schwidefsky@de.ibm.com>

Showing 2 changed files with 14 additions and 2 deletions Side-by-side Diff

arch/s390/kernel/entry.S
Diff comments   View file @ 176b180
... ... @@ -964,7 +964,7 @@
964 964 clc 4(4,%r12),BASED(cleanup_table_io_work_loop)
965 965 bl BASED(0f)
966 966 clc 4(4,%r12),BASED(cleanup_table_io_work_loop+4)
967   - bl BASED(cleanup_io_return)
  967 + bl BASED(cleanup_io_work_loop)
968 968 0:
969 969 br %r14
970 970  
... ... @@ -1038,6 +1038,12 @@
1038 1038 .long sysc_done - 8 + 0x80000000
1039 1039  
1040 1040 cleanup_io_return:
  1041 + mvc __LC_RETURN_PSW(4),0(%r12)
  1042 + mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_io_return)
  1043 + la %r12,__LC_RETURN_PSW
  1044 + br %r14
  1045 +
  1046 +cleanup_io_work_loop:
1041 1047 mvc __LC_RETURN_PSW(4),0(%r12)
1042 1048 mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_io_work_loop)
1043 1049 la %r12,__LC_RETURN_PSW
arch/s390/kernel/entry64.S
Diff comments   View file @ 176b180
... ... @@ -946,7 +946,7 @@
946 946 clc 8(8,%r12),BASED(cleanup_table_io_work_loop)
947 947 jl 0f
948 948 clc 8(8,%r12),BASED(cleanup_table_io_work_loop+8)
949   - jl cleanup_io_return
  949 + jl cleanup_io_work_loop
950 950 0:
951 951 br %r14
952 952  
... ... @@ -1020,6 +1020,12 @@
1020 1020 .quad sysc_done - 16
1021 1021  
1022 1022 cleanup_io_return:
  1023 + mvc __LC_RETURN_PSW(8),0(%r12)
  1024 + mvc __LC_RETURN_PSW+8(8),BASED(cleanup_table_io_return)
  1025 + la %r12,__LC_RETURN_PSW
  1026 + br %r14
  1027 +
  1028 +cleanup_io_work_loop:
1023 1029 mvc __LC_RETURN_PSW(8),0(%r12)
1024 1030 mvc __LC_RETURN_PSW+8(8),BASED(cleanup_table_io_work_loop)
1025 1031 la %r12,__LC_RETURN_PSW