parisc: entry: set W bit for !compat tasks in syscall_restore_rfi()

commit 5fb1d3ce3e74a4530042795e1e065422295f1371 upstream.

When the kernel leaves to userspace via syscall_restore_rfi(), the
W bit is not set in the new PSW. This doesn't cause any problems
because there's no 64 bit userspace for parisc. Simple static binaries
are usually loaded at addresses way below the 32 bit limit so the W bit
doesn't matter.

Fix this by setting the W bit when TIF_32BIT is not set.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/parisc/kernel/asm-offsets.c b/arch/parisc/kernel/asm-offsets.c
index 9abfe65492c65eadbc69d7a6fa01b2fbab5ad285..3de4b5933b107962a6f40fd098f8fc359cf4b064 100644 (file)
--- a/arch/parisc/kernel/asm-offsets.c
+++ b/arch/parisc/kernel/asm-offsets.c
@@ -258,6 +258,8 @@ int main(void)
        BLANK();
        DEFINE(TIF_BLOCKSTEP_PA_BIT, 31-TIF_BLOCKSTEP);
        DEFINE(TIF_SINGLESTEP_PA_BIT, 31-TIF_SINGLESTEP);
+       DEFINE(TIF_32BIT_PA_BIT, 31-TIF_32BIT);
+
        BLANK();
        DEFINE(ASM_PMD_SHIFT, PMD_SHIFT);
        DEFINE(ASM_PGDIR_SHIFT, PGDIR_SHIFT);

diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index bb383487e302d1b33256f75cc67d15e6e6ef4059..e04c5d806c10517827d2d4b0ab3888f1156b6e25 100644 (file)
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -1846,6 +1846,10 @@ syscall_restore_rfi:
        extru,= %r19,TIF_BLOCKSTEP_PA_BIT,1,%r0
        depi    -1,7,1,%r20                        /* T bit */
 
+#ifdef CONFIG_64BIT
+       extru,<> %r19,TIF_32BIT_PA_BIT,1,%r0
+       depi    -1,4,1,%r20                        /* W bit */
+#endif
        STREG   %r20,TASK_PT_PSW(%r1)
 
        /* Always store space registers, since sr3 can be changed (e.g. fork) */
@@ -1859,7 +1863,6 @@ syscall_restore_rfi:
        STREG   %r25,TASK_PT_IASQ0(%r1)
        STREG   %r25,TASK_PT_IASQ1(%r1)
 
-       /* XXX W bit??? */
        /* Now if old D bit is clear, it means we didn't save all registers
         * on syscall entry, so do that now.  This only happens on TRACEME
         * calls, or if someone attached to us while we were on a syscall.