[PATCH 6.18 127/277] riscv: Reset pmm when PR_TAGGED_ADDR_ENABLE is not set

Greg Kroah-Hartman
2026-04-08T18:32:45Z

From: Zishun Yi <vulab@iscas.ac.cn>

[ Upstream commit 3033b2b1e3949274f33a140e2a97571b5a307298 ]

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>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://patch.msgid.link/20260322160022.21908-1-vulab@iscas.ac.cn
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 31a392993cb45..b5188dc74727d 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -324,8 +324,10 @@ 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;
--
2.53.0