riscv: Reset pmm when PR_TAGGED_ADDR_ENABLE is not set

[PATCH] riscv: Reset pmm when PR_TAGGED_ADDR_ENABLE is not set

Posted by Zishun Yi 1 week, 5 days ago

In set_tagged_addr_ctrl(), when PR_TAGGED_ADDR_ENABLE is not set, pmlen
is correctly set to 0, but it forgets to reset pmm. This results in the
CPU pmm state not corresponding to the software pmlen state.

Fix this by resetting pmm along with pmlen.

Fixes: 2e1743085887 ("riscv: Add support for the tagged address ABI")
Signed-off-by: Zishun Yi <vulab@iscas.ac.cn>
---
 arch/riscv/kernel/process.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index aacb23978f93..5957effab57c 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -347,8 +347,10 @@ long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg)
 	if (arg & PR_TAGGED_ADDR_ENABLE && (tagged_addr_disabled || !pmlen))
 		return -EINVAL;
 
-	if (!(arg & PR_TAGGED_ADDR_ENABLE))
+	if (!(arg & PR_TAGGED_ADDR_ENABLE)) {
 		pmlen = PMLEN_0;
+		pmm = ENVCFG_PMM_PMLEN_0;
+	}
 
 	if (mmap_write_lock_killable(mm))
 		return -EINTR;
-- 
2.51.2

Re: [PATCH] riscv: Reset pmm when PR_TAGGED_ADDR_ENABLE is not set

Posted by Paul Walmsley 1 week, 2 days ago

On Mon, 23 Mar 2026, Zishun Yi wrote:

> In set_tagged_addr_ctrl(), when PR_TAGGED_ADDR_ENABLE is not set, pmlen
> is correctly set to 0, but it forgets to reset pmm. This results in the
> CPU pmm state not corresponding to the software pmlen state.
> 
> Fix this by resetting pmm along with pmlen.
> 
> Fixes: 2e1743085887 ("riscv: Add support for the tagged address ABI")
> Signed-off-by: Zishun Yi <vulab@iscas.ac.cn>

Thanks, queued for v7.0-rc.


- Paul

Re: [PATCH] riscv: Reset pmm when PR_TAGGED_ADDR_ENABLE is not set

Posted by Samuel Holland 1 week, 4 days ago

On 2026-03-22 11:00 AM, Zishun Yi wrote:
> In set_tagged_addr_ctrl(), when PR_TAGGED_ADDR_ENABLE is not set, pmlen
> is correctly set to 0, but it forgets to reset pmm. This results in the
> CPU pmm state not corresponding to the software pmlen state.
> 
> Fix this by resetting pmm along with pmlen.
> 
> Fixes: 2e1743085887 ("riscv: Add support for the tagged address ABI")
> Signed-off-by: Zishun Yi <vulab@iscas.ac.cn>

Thanks for the fix!

Reviewed-by: Samuel Holland <samuel.holland@sifive.com>

> ---
>  arch/riscv/kernel/process.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
> index aacb23978f93..5957effab57c 100644
> --- a/arch/riscv/kernel/process.c
> +++ b/arch/riscv/kernel/process.c
> @@ -347,8 +347,10 @@ long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg)
>  	if (arg & PR_TAGGED_ADDR_ENABLE && (tagged_addr_disabled || !pmlen))
>  		return -EINVAL;
>  
> -	if (!(arg & PR_TAGGED_ADDR_ENABLE))
> +	if (!(arg & PR_TAGGED_ADDR_ENABLE)) {
>  		pmlen = PMLEN_0;
> +		pmm = ENVCFG_PMM_PMLEN_0;
> +	}
>  
>  	if (mmap_write_lock_killable(mm))
>  		return -EINTR;