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riscv: Disable Vector Instructions for kernel itself

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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>
Link: https://lore.kernel.org/r/20230605110724.21391-7-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Guo Ren
2023-06-05 11:07:03 +00:00
committed by Palmer Dabbelt
parent 6b53382872
commit 74abe5a39d
2 changed files with 9 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
arch/riscv/kernel/entry.S
View File

@@ -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

12
arch/riscv/kernel/head.S
View File

@@ -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