[S390] move (io|sysc)_restore_trace_psw into .data section
authorHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Fri, 11 Sep 2009 08:28:42 +0000 (10:28 +0200)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Fri, 11 Sep 2009 08:29:47 +0000 (10:29 +0200)
The sysc_restore_trace_psw and io_restore_trace_psw storage locations
are created in the .text section. When creating and IPLing from a named
saved system (NSS), writing to these locations causes a protection exception
(because the .text section is mapped as shared read-only in the NSS).

To permit write access, move the storage locations into the .data section.

The problem occurs only when CONFIG_TRACE_IRQFLAGS is set.
The git commmit that has introduced these variables is:
411788ea7fca01ee803af8225ac35807b4d02050

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/kernel/entry.S
arch/s390/kernel/entry64.S

index c4c80a2..f78580a 100644 (file)
@@ -278,7 +278,8 @@ sysc_return:
        bnz     BASED(sysc_work)  # there is work to do (signals etc.)
 sysc_restore:
 #ifdef CONFIG_TRACE_IRQFLAGS
-       la      %r1,BASED(sysc_restore_trace_psw)
+       la      %r1,BASED(sysc_restore_trace_psw_addr)
+       l       %r1,0(%r1)
        lpsw    0(%r1)
 sysc_restore_trace:
        TRACE_IRQS_CHECK
@@ -289,10 +290,15 @@ sysc_leave:
 sysc_done:
 
 #ifdef CONFIG_TRACE_IRQFLAGS
+sysc_restore_trace_psw_addr:
+       .long sysc_restore_trace_psw
+
+       .section .data,"aw",@progbits
        .align  8
        .globl  sysc_restore_trace_psw
 sysc_restore_trace_psw:
        .long   0, sysc_restore_trace + 0x80000000
+       .previous
 #endif
 
 #
@@ -606,7 +612,8 @@ io_return:
        bnz     BASED(io_work)          # there is work to do (signals etc.)
 io_restore:
 #ifdef CONFIG_TRACE_IRQFLAGS
-       la      %r1,BASED(io_restore_trace_psw)
+       la      %r1,BASED(io_restore_trace_psw_addr)
+       l       %r1,0(%r1)
        lpsw    0(%r1)
 io_restore_trace:
        TRACE_IRQS_CHECK
@@ -617,10 +624,15 @@ io_leave:
 io_done:
 
 #ifdef CONFIG_TRACE_IRQFLAGS
+io_restore_trace_psw_addr:
+       .long io_restore_trace_psw
+
+       .section .data,"aw",@progbits
        .align  8
        .globl  io_restore_trace_psw
 io_restore_trace_psw:
        .long   0, io_restore_trace + 0x80000000
+       .previous
 #endif
 
 #
index f6618e9..009ca61 100644 (file)
@@ -284,10 +284,12 @@ sysc_leave:
 sysc_done:
 
 #ifdef CONFIG_TRACE_IRQFLAGS
+       .section .data,"aw",@progbits
        .align  8
        .globl sysc_restore_trace_psw
 sysc_restore_trace_psw:
        .quad   0, sysc_restore_trace
+       .previous
 #endif
 
 #
@@ -595,10 +597,12 @@ io_leave:
 io_done:
 
 #ifdef CONFIG_TRACE_IRQFLAGS
+       .section .data,"aw",@progbits
        .align  8
        .globl io_restore_trace_psw
 io_restore_trace_psw:
        .quad   0, io_restore_trace
+       .previous
 #endif
 
 #