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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
	Damien Le Moal <damien.lemoal@wdc.com>,
	Palmer Dabbelt <palmerdabbelt@google.com>,
	linux-riscv@lists.infradead.org
Subject: [PATCH AUTOSEL 5.10 16/45] riscv: Enable interrupts during syscalls with M-Mode
Date: Tue, 19 Jan 2021 20:25:33 -0500	[thread overview]
Message-ID: <20210120012602.769683-16-sashal@kernel.org> (raw)
In-Reply-To: <20210120012602.769683-1-sashal@kernel.org>

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)
-- 
2.27.0


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  parent reply	other threads:[~2021-01-20  1:26 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20210120012602.769683-1-sashal@kernel.org>
2021-01-20  1:25 ` [PATCH AUTOSEL 5.10 14/45] riscv: Fix kernel time_init() Sasha Levin
2021-01-20  1:25 ` [PATCH AUTOSEL 5.10 15/45] riscv: Fix sifive serial driver Sasha Levin
2021-01-20  1:25 ` Sasha Levin [this message]
2021-01-20  1:25 ` [PATCH AUTOSEL 5.10 22/45] riscv: cacheinfo: Fix using smp_processor_id() in preemptible Sasha Levin
2021-01-20  1:25 ` [PATCH AUTOSEL 5.10 29/45] dts: phy: fix missing mdio device and probe failure of vsc8541-01 device Sasha Levin
2021-01-20  1:25 ` [PATCH AUTOSEL 5.10 30/45] dts: phy: add GPIO number and active state used for phy reset Sasha Levin
2021-01-20  1:25 ` [PATCH AUTOSEL 5.10 31/45] riscv: defconfig: enable gpio support for HiFive Unleashed Sasha Levin
2021-01-20  1:26 ` [PATCH AUTOSEL 5.10 44/45] RISC-V: Set current memblock limit Sasha Levin
2021-01-20  1:26 ` [PATCH AUTOSEL 5.10 45/45] RISC-V: Fix maximum allowed phsyical memory for RV32 Sasha Levin

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