nios2: fixed broken sys_clone syscall

[ Upstream commit 9abcfcb20320e8f693e89d86573b58e6289931cb ]

The tls pointer must be pushed on the stack prior to calling nios2_clone
as it is the 5th function argument. Prior handling of the tls pointer was
done inside former called function copy_thread_tls using the r8 register
from the current_pt_regs directly. This was a bad design and resulted in
the current bug introduced in 04bd52fb.

Fixes: 04bd52fb ("nios2: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args")
Signed-off-by: Andreas Oetken <andreas.oetken@siemens.com>
Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/nios2/kernel/entry.S b/arch/nios2/kernel/entry.S
index da84424..0794cd7 100644 (file)
--- a/arch/nios2/kernel/entry.S
+++ b/arch/nios2/kernel/entry.S
@@ -389,7 +389,10 @@ ENTRY(ret_from_interrupt)
  */
 ENTRY(sys_clone)
        SAVE_SWITCH_STACK
+       subi    sp, sp, 4 /* make space for tls pointer */
+       stw     r8, 0(sp) /* pass tls pointer (r8) via stack (5th argument) */
        call    nios2_clone
+       addi    sp, sp, 4
        RESTORE_SWITCH_STACK
        ret