riscv: Enable interrupts during syscalls with M-Mode

[ 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>
This commit is contained in:
Damien Le Moal 2020-12-13 22:50:36 +09:00 committed by Greg Kroah-Hartman
parent 094a4af043
commit 6bc83cce3e

View File

@ -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)