From: Damien Le Moal damien.lemoal@wdc.com
[ Upstream commit 643437b996bac9267785e0bd528332e2d5811067 ]
When running is M-Mode (no MMU config), MPIE does not get set. This results in all syscalls being executed with interrupts disabled as handle_exception never sets SR_IE as it always sees SR_PIE being cleared. Fix this by always force enabling interrupts in handle_syscall when CONFIG_RISCV_M_MODE is enabled.
Signed-off-by: Damien Le Moal damien.lemoal@wdc.com Reviewed-by: Palmer Dabbelt palmerdabbelt@google.com Signed-off-by: Palmer Dabbelt palmerdabbelt@google.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/riscv/kernel/entry.S | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 524d918f3601b..080eb8d78589d 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -155,6 +155,15 @@ skip_context_tracking: tail do_trap_unknown
handle_syscall: +#ifdef CONFIG_RISCV_M_MODE + /* + * When running is M-Mode (no MMU config), MPIE does not get set. + * As a result, we need to force enable interrupts here because + * handle_exception did not do set SR_IE as it always sees SR_PIE + * being cleared. + */ + csrs CSR_STATUS, SR_IE +#endif #if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING) /* Recover a0 - a7 for system calls */ REG_L a0, PT_A0(sp)