[PATCH 11/32] riscv: Enable interrupts during syscalls with M-Mode
From: Damien Le Moal <hidden>
Date: 2020-11-07 08:14:55
Also in:
linux-clk, linux-gpio, linux-riscv, linux-spi
Subsystem:
risc-v architecture, the rest · Maintainers:
Paul Walmsley, Palmer Dabbelt, Albert Ou, Linus Torvalds
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 <redacted> --- 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 524d918f3601..080eb8d78589 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)
--
2.28.0