sparc64: don't treat 64-bit syscall return codes as 32-bit

[ Upstream commit 1535bd8adbdedd60a0ee62e28fd5225d66434371 ]

When checking a system call return code for an error,
linux_sparc_syscall was sign-extending the lower 32-bit value and
comparing it to -ERESTART_RESTARTBLOCK. lseek can return valid return
codes whose lower 32-bits alone would indicate a failure (such as 4G-1).
Use the whole 64-bit value to check for errors. Only the 32-bit path
should sign extend the lower 32-bit value.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Acked-by: Bob Picco <bob.picco@oracle.com>
Acked-by: Allen Pais <allen.pais@oracle.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/arch/sparc/kernel/syscalls.S b/arch/sparc/kernel/syscalls.S
index 817187d..557212c 100644 (file)
--- a/arch/sparc/kernel/syscalls.S
+++ b/arch/sparc/kernel/syscalls.S
@@ -184,7 +184,8 @@ linux_sparc_syscall32:
         mov    %i0, %l5                                ! IEU1
 5:     call    %l7                                     ! CTI   Group brk forced
         srl    %i5, 0, %o5                             ! IEU1
-       ba,a,pt %xcc, 3f
+       ba,pt   %xcc, 3f
+        sra    %o0, 0, %o0
 
        /* Linux native system calls enter here... */
        .align  32
@@ -212,7 +213,6 @@ linux_sparc_syscall:
 3:     stx     %o0, [%sp + PTREGS_OFF + PT_V9_I0]
 ret_sys_call:
        ldx     [%sp + PTREGS_OFF + PT_V9_TSTATE], %g3
-       sra     %o0, 0, %o0
        mov     %ulo(TSTATE_XCARRY | TSTATE_ICARRY), %g2
        sllx    %g2, 32, %g2