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 22924a3f17283f0fa71d51d706d1479128996052..e8f8c3d8a2abcab76adda2154ea41cf2c6fee00b 100644 (file)
--- a/arch/parisc/kernel/asm-offsets.c
+++ b/arch/parisc/kernel/asm-offsets.c
@@ -260,6 +260,8 @@ 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 1effebb5c193695b8133ec3cf56f29e78e554259..b75bd059d79d9dde839be6da4b28183dbea55552 100644 (file)
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -1913,6 +1913,10 @@ 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) */
@@ -1926,7 +1930,6 @@ 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.