sparc32: Preserve clone syscall flags argument for restarts due to signals

This fixes a bug where a clone syscall that is restarted due to a
pending signal is restarted with garbage in the register %o0 that holds
the clone flags.

This keep the original %i0 of a syscall (as seen from the trap handler)
in %l6 rather than %l5. This is done because for clone (and also qfork)
%l5 is used as a temporary variable in the same register window. Before
this, that temporary value would be the value that was then incorrectly
used as the orig_i0 argument to do_notify_resume.

In order to preserve %l6, the temporary usage of %l6 in ret_sys_call is
changed to use %l5 instead and the setting %l6 to 0 or 1 was removed.
The use of that 0 or 1 value in %l6 was removed in commit
28e6103665301ce60634e8a77f0b657c6cc099de.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/arch/sparc/kernel/entry.S b/arch/sparc/kernel/entry.S
index f636acf3312f68ee5c7ee322821375c222583527..c385c93b39bc1dc3e1ad66087f8688fb1468144f 100644 (file)
--- a/arch/sparc/kernel/entry.S
+++ b/arch/sparc/kernel/entry.S
@@ -1009,7 +1009,7 @@ do_syscall:
        andcc   %l5, _TIF_SYSCALL_TRACE, %g0
        mov     %i4, %o4
        bne     linux_syscall_trace
-        mov    %i0, %l5
+        mov    %i0, %l6
 2:
        call    %l7
         mov    %i5, %o5
@@ -1018,16 +1018,15 @@ do_syscall:
        st      %o0, [%sp + STACKFRAME_SZ + PT_I0]
 
 ret_sys_call:
-       ld      [%curptr + TI_FLAGS], %l6
+       ld      [%curptr + TI_FLAGS], %l5
        cmp     %o0, -ERESTART_RESTARTBLOCK
        ld      [%sp + STACKFRAME_SZ + PT_PSR], %g3
        set     PSR_C, %g2
        bgeu    1f
-        andcc  %l6, _TIF_SYSCALL_TRACE, %g0
+        andcc  %l5, _TIF_SYSCALL_TRACE, %g0
 
        /* System call success, clear Carry condition code. */
        andn    %g3, %g2, %g3
-       clr     %l6
        st      %g3, [%sp + STACKFRAME_SZ + PT_PSR]     
        bne     linux_syscall_trace2
         ld     [%sp + STACKFRAME_SZ + PT_NPC], %l1 /* pc = npc */
@@ -1042,7 +1041,6 @@ ret_sys_call:
        sub     %g0, %o0, %o0
        or      %g3, %g2, %g3
        st      %o0, [%sp + STACKFRAME_SZ + PT_I0]
-       mov     1, %l6
        st      %g3, [%sp + STACKFRAME_SZ + PT_PSR]
        bne     linux_syscall_trace2
         ld     [%sp + STACKFRAME_SZ + PT_NPC], %l1 /* pc = npc */

diff --git a/arch/sparc/kernel/rtrap_32.S b/arch/sparc/kernel/rtrap_32.S
index dca8ed81004660458e6961c5270c738340013936..8931fe266346a3275cfffa7e6c3e6de6ec459b0a 100644 (file)
--- a/arch/sparc/kernel/rtrap_32.S
+++ b/arch/sparc/kernel/rtrap_32.S
@@ -75,7 +75,7 @@ signal_p:
         ld     [%sp + STACKFRAME_SZ + PT_PSR], %t_psr
 
        mov     %g2, %o2
-       mov     %l5, %o1
+       mov     %l6, %o1
        call    do_notify_resume
         add    %sp, STACKFRAME_SZ, %o0 ! pt_regs ptr