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[-next,v20,06/26] riscv: Disable Vector Instructions for kernel itself

Message ID 20230518161949.11203-7-andy.chiu@sifive.com (mailing list archive)
State Superseded
Headers show
Series riscv: Add vector ISA support | expand

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conchuod/maintainers_pattern success MAINTAINERS pattern errors before the patch: 6 and now 6
conchuod/verify_signedoff success Signed-off-by tag matches author and committer
conchuod/kdoc success Errors and warnings before: 0 this patch: 0
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conchuod/build_rv64_gcc_allmodconfig success Errors and warnings before: 8 this patch: 8
conchuod/build_rv32_defconfig success Build OK
conchuod/dtb_warn_rv64 success Errors and warnings before: 3 this patch: 3
conchuod/header_inline success No static functions without inline keyword in header files
conchuod/checkpatch success total: 0 errors, 0 warnings, 0 checks, 39 lines checked
conchuod/build_rv64_nommu_k210_defconfig success Build OK
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conchuod/build_rv64_nommu_virt_defconfig success Build OK

Commit Message

Andy Chiu May 18, 2023, 4:19 p.m. UTC
From: Guo Ren <guoren@linux.alibaba.com>

Disable vector instructions execution for kernel mode at its entrances.
This helps find illegal uses of vector in the kernel space, which is
similar to the fpu.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Co-developed-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Co-developed-by: Han-Kuan Chen <hankuan.chen@sifive.com>
Signed-off-by: Han-Kuan Chen <hankuan.chen@sifive.com>
Co-developed-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Vineet Gupta <vineetg@rivosinc.com>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
---
Changelog V19:
 - Add description in commit msg (Heiko's suggestion on v17)
---
 arch/riscv/kernel/entry.S |  6 +++---
 arch/riscv/kernel/head.S  | 12 ++++++------
 2 files changed, 9 insertions(+), 9 deletions(-)
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Patch

diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index 3fbb100bc9e4..e9ae284a55c1 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -48,10 +48,10 @@  _save_context:
 	 * Disable user-mode memory access as it should only be set in the
 	 * actual user copy routines.
 	 *
-	 * Disable the FPU to detect illegal usage of floating point in kernel
-	 * space.
+	 * Disable the FPU/Vector to detect illegal usage of floating point
+	 * or vector in kernel space.
 	 */
-	li t0, SR_SUM | SR_FS
+	li t0, SR_SUM | SR_FS_VS
 
 	REG_L s0, TASK_TI_USER_SP(tp)
 	csrrc s1, CSR_STATUS, t0
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index 3fd6a4bd9c3e..e16bb2185d55 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -140,10 +140,10 @@  secondary_start_sbi:
 	.option pop
 
 	/*
-	 * Disable FPU to detect illegal usage of
-	 * floating point in kernel space
+	 * Disable FPU & VECTOR to detect illegal usage of
+	 * floating point or vector in kernel space
 	 */
-	li t0, SR_FS
+	li t0, SR_FS_VS
 	csrc CSR_STATUS, t0
 
 	/* Set trap vector to spin forever to help debug */
@@ -234,10 +234,10 @@  pmp_done:
 .option pop
 
 	/*
-	 * Disable FPU to detect illegal usage of
-	 * floating point in kernel space
+	 * Disable FPU & VECTOR to detect illegal usage of
+	 * floating point or vector in kernel space
 	 */
-	li t0, SR_FS
+	li t0, SR_FS_VS
 	csrc CSR_STATUS, t0
 
 #ifdef CONFIG_RISCV_BOOT_SPINWAIT