riscv: Return to previous privilege level after trap handling
At present the trap handler returns to hardcoded M-mode/S-mode.
Change to returning to previous privilege level instead.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
diff --git a/arch/riscv/cpu/mtrap.S b/arch/riscv/cpu/mtrap.S
index da307e4..407ecfa 100644
--- a/arch/riscv/cpu/mtrap.S
+++ b/arch/riscv/cpu/mtrap.S
@@ -68,14 +68,6 @@
jal handle_trap
csrw MODE_PREFIX(epc), a0
-#ifdef CONFIG_RISCV_SMODE
- /* Remain in S-mode after sret */
- li t0, SSTATUS_SPP
-#else
- /* Remain in M-mode after mret */
- li t0, MSTATUS_MPP
-#endif
- csrs MODE_PREFIX(status), t0
LREG x1, 1 * REGBYTES(sp)
LREG x3, 3 * REGBYTES(sp)
LREG x4, 4 * REGBYTES(sp)