Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / s390 / kernel / entry64.S

diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 07d8de353984da0fd8c8792348cebba214391c0c..6d34e0c97a3948fde034acedabfec98af203e64b 100644 (file)
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -80,14 +80,21 @@ _TIF_EXIT_SIE = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING)
 #endif
        .endm
 
-       .macro  HANDLE_SIE_INTERCEPT scratch
+       .macro  HANDLE_SIE_INTERCEPT scratch,pgmcheck
 #if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE)
        tmhh    %r8,0x0001              # interrupting from user ?
        jnz     .+42
        lgr     \scratch,%r9
        slg     \scratch,BASED(.Lsie_loop)
        clg     \scratch,BASED(.Lsie_length)
+       .if     \pgmcheck
+       # Some program interrupts are suppressing (e.g. protection).
+       # We must also check the instruction after SIE in that case.
+       # do_protection_exception will rewind to rewind_pad
+       jh      .+22
+       .else
        jhe     .+22
+       .endif
        lg      %r9,BASED(.Lsie_loop)
        SPP     BASED(.Lhost_id)        # set host id
 #endif
@@ -262,12 +269,12 @@ sysc_work:
        jo      sysc_mcck_pending
        tm      __TI_flags+7(%r12),_TIF_NEED_RESCHED
        jo      sysc_reschedule
+       tm      __TI_flags+7(%r12),_TIF_PER_TRAP
+       jo      sysc_singlestep
        tm      __TI_flags+7(%r12),_TIF_SIGPENDING
        jo      sysc_sigpending
        tm      __TI_flags+7(%r12),_TIF_NOTIFY_RESUME
        jo      sysc_notify_resume
-       tm      __TI_flags+7(%r12),_TIF_PER_TRAP
-       jo      sysc_singlestep
        j       sysc_return             # beware of critical section cleanup
 
 #
@@ -288,7 +295,6 @@ sysc_mcck_pending:
 # _TIF_SIGPENDING is set, call do_signal
 #
 sysc_sigpending:
-       ni      __TI_flags+7(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
        lgr     %r2,%r11                # pass pointer to pt_regs
        brasl   %r14,do_signal
        tm      __TI_flags+7(%r12),_TIF_SYSCALL
@@ -313,7 +319,7 @@ sysc_notify_resume:
 # _TIF_PER_TRAP is set, call do_per_trap
 #
 sysc_singlestep:
-       ni      __TI_flags+7(%r12),255-(_TIF_SYSCALL | _TIF_PER_TRAP)
+       ni      __TI_flags+7(%r12),255-_TIF_PER_TRAP
        lgr     %r2,%r11                # pass pointer to pt_regs
        larl    %r14,sysc_return
        jg      do_per_trap
@@ -352,33 +358,17 @@ sysc_tracenogo:
 ENTRY(ret_from_fork)
        la      %r11,STACK_FRAME_OVERHEAD(%r15)
        lg      %r12,__LC_THREAD_INFO
-       tm      __PT_PSW+1(%r11),0x01   # forking a kernel thread ?
-       je      1f
-       brasl   %r14,schedule_tail
-       TRACE_IRQS_ON
-       ssm     __LC_SVC_NEW_PSW        # reenable interrupts
-       j       sysc_tracenogo
-1:     # it's a kernel thread
-       stg     %r15,__PT_R15(%r11)     # store stack pointer for new kthread
        brasl   %r14,schedule_tail
        TRACE_IRQS_ON
        ssm     __LC_SVC_NEW_PSW        # reenable interrupts
-       lmg     %r9,%r11,__PT_R9(%r11)  # load gprs
+       tm      __PT_PSW+1(%r11),0x01   # forking a kernel thread ?
+       jne     sysc_tracenogo
+       # it's a kernel thread
+       lmg     %r9,%r10,__PT_R9(%r11)  # load gprs
 ENTRY(kernel_thread_starter)
        la      %r2,0(%r10)
        basr    %r14,%r9
-       la      %r2,0
-       br      %r11                    # do_exit
-
-ENTRY(ret_from_kernel_execve)
-       ssm     __LC_PGM_NEW_PSW        # disable I/O and ext. interrupts
-       lgr     %r15,%r2
-       lgr     %r11,%r2
-       aghi    %r15,-STACK_FRAME_OVERHEAD
-       xc      __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
-       lg      %r12,__LC_THREAD_INFO
-       ssm     __LC_SVC_NEW_PSW        # reenable interrupts
-       j       sysc_return
+       j       sysc_tracenogo
 
 /*
  * Program check handler routine
@@ -391,7 +381,7 @@ ENTRY(pgm_check_handler)
        lg      %r12,__LC_THREAD_INFO
        larl    %r13,system_call
        lmg     %r8,%r9,__LC_PGM_OLD_PSW
-       HANDLE_SIE_INTERCEPT %r14
+       HANDLE_SIE_INTERCEPT %r14,1
        tmhh    %r8,0x0001              # test problem state bit
        jnz     1f                      # -> fault in user space
        tmhh    %r8,0x4000              # PER bit set in old PSW ?
@@ -429,9 +419,9 @@ ENTRY(pgm_check_handler)
        larl    %r1,pgm_check_table
        llgh    %r10,__PT_INT_CODE+2(%r11)
        nill    %r10,0x007f
-       sll     %r10,3
+       sll     %r10,2
        je      sysc_return
-       lg      %r1,0(%r10,%r1)         # load address of handler routine
+       lgf     %r1,0(%r10,%r1)         # load address of handler routine
        lgr     %r2,%r11                # pass pointer to pt_regs
        basr    %r14,%r1                # branch to interrupt-handler
        j       sysc_return
@@ -467,7 +457,7 @@ ENTRY(io_int_handler)
        lg      %r12,__LC_THREAD_INFO
        larl    %r13,system_call
        lmg     %r8,%r9,__LC_IO_OLD_PSW
-       HANDLE_SIE_INTERCEPT %r14
+       HANDLE_SIE_INTERCEPT %r14,0
        SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
        tmhh    %r8,0x0001              # interrupting from user?
        jz      io_skip
@@ -613,7 +603,7 @@ ENTRY(ext_int_handler)
        lg      %r12,__LC_THREAD_INFO
        larl    %r13,system_call
        lmg     %r8,%r9,__LC_EXT_OLD_PSW
-       HANDLE_SIE_INTERCEPT %r14
+       HANDLE_SIE_INTERCEPT %r14,0
        SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
        tmhh    %r8,0x0001              # interrupting from user ?
        jz      ext_skip
@@ -661,7 +651,7 @@ ENTRY(mcck_int_handler)
        lg      %r12,__LC_THREAD_INFO
        larl    %r13,system_call
        lmg     %r8,%r9,__LC_MCK_OLD_PSW
-       HANDLE_SIE_INTERCEPT %r14
+       HANDLE_SIE_INTERCEPT %r14,0
        tm      __LC_MCCK_CODE,0x80     # system damage?
        jo      mcck_panic              # yes -> rest of mcck code invalid
        lghi    %r14,__LC_CPU_TIMER_SAVE_AREA
@@ -960,6 +950,13 @@ ENTRY(sie64a)
        stg     %r3,__SF_EMPTY+8(%r15)          # save guest register save area
        xc      __SF_EMPTY+16(8,%r15),__SF_EMPTY+16(%r15) # host id == 0
        lmg     %r0,%r13,0(%r3)                 # load guest gprs 0-13
+# some program checks are suppressing. C code (e.g. do_protection_exception)
+# will rewind the PSW by the ILC, which is 4 bytes in case of SIE. Other
+# instructions in the sie_loop should not cause program interrupts. So
+# lets use a nop (47 00 00 00) as a landing pad.
+# See also HANDLE_SIE_INTERCEPT
+rewind_pad:
+       nop     0
 sie_loop:
        lg      %r14,__LC_THREAD_INFO           # pointer thread_info struct
        tm      __TI_flags+7(%r14),_TIF_EXIT_SIE
@@ -999,6 +996,7 @@ sie_fault:
 .Lhost_id:
        .quad   0
 
+       EX_TABLE(rewind_pad,sie_fault)
        EX_TABLE(sie_loop,sie_fault)
 #endif