[S390] Fix IRQ tracing in case of PER

In case user space is single stepped (PER) the program check handler
claims too early that IRQs are enabled on the return path.
Subsequent checks will notice that the IRQ mask in the PSW and
what lockdep thinks the IRQ mask should be do not correlate and
therefore will print a warning to the console and disable lockdep.

Fix this by doing all the work within the correct context.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index d5e3e60..bea9ee3 100644 (file)
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -535,8 +535,16 @@ pgm_no_vtime2:
        l       %r3,__LC_PGM_ILC        # load program interruption code
        la      %r8,0x7f
        nr      %r8,%r3                 # clear per-event-bit and ilc
-       be      BASED(pgm_exit)         # only per or per+check ?
-       b       BASED(pgm_do_call)
+       be      BASED(pgm_exit2)        # only per or per+check ?
+       l       %r7,BASED(.Ljump_table)
+       sll     %r8,2
+       l       %r7,0(%r8,%r7)          # load address of handler routine
+       la      %r2,SP_PTREGS(%r15)     # address of register-save area
+       basr    %r14,%r7                # branch to interrupt-handler
+pgm_exit2:
+       TRACE_IRQS_ON
+       stosm   __SF_EMPTY(%r15),0x03   # reenable interrupts
+       b       BASED(sysc_return)
 
 #
 # it was a single stepped SVC that is causing all the trouble

diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index e7192e1..8bccec1 100644 (file)
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -544,8 +544,16 @@ pgm_no_vtime2:
        lgf     %r3,__LC_PGM_ILC        # load program interruption code
        lghi    %r8,0x7f
        ngr     %r8,%r3                 # clear per-event-bit and ilc
-       je      pgm_exit
-       j       pgm_do_call
+       je      pgm_exit2
+       sll     %r8,3
+       larl    %r1,pgm_check_table
+       lg      %r1,0(%r8,%r1)          # load address of handler routine
+       la      %r2,SP_PTREGS(%r15)     # address of register-save area
+       basr    %r14,%r1                # branch to interrupt-handler
+pgm_exit2:
+       TRACE_IRQS_ON
+       stosm   __SF_EMPTY(%r15),0x03   # reenable interrupts
+       j       sysc_return
 
 #
 # it was a single stepped SVC that is causing all the trouble