2023-07-12 12:18:21

by Song Shuai

[permalink] [raw]
Subject: [PATCH V2] riscv: correct pt_level name via pgtable_l5/4_enabled

The pt_level uses CONFIG_PGTABLE_LEVELS to display page table names.
But if page mode is downgraded from kernel cmdline or restricted by
the hardware in 64BIT, it will give a wrong name.

Like, using no4lvl for sv39, ptdump named the 1G-mapping as "PUD"
that should be "PGD":

0xffffffd840000000-0xffffffd900000000 0x00000000c0000000 3G PUD D A G . . W R V

So select "P4D/PUD" or "PGD" via pgtable_l5/4_enabled to correct it.

Fixes: e8a62cc26ddf ("riscv: Implement sv48 support")
Reviewed-by: Alexandre Ghiti <[email protected]>
Signed-off-by: Song Shuai <[email protected]>
---
Changes since V1:
https://lore.kernel.org/linux-riscv/[email protected]/
- remove the reduntant #ifdef
- correct the Fixes tag and add Reviewed-by from Alex
---
arch/riscv/mm/ptdump.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c
index 20a9f991a6d7..e9090b38f811 100644
--- a/arch/riscv/mm/ptdump.c
+++ b/arch/riscv/mm/ptdump.c
@@ -384,6 +384,9 @@ static int __init ptdump_init(void)

kernel_ptd_info.base_addr = KERN_VIRT_START;

+ pg_level[1].name = pgtable_l5_enabled ? "P4D" : "PGD";
+ pg_level[2].name = pgtable_l4_enabled ? "PUD" : "PGD";
+
for (i = 0; i < ARRAY_SIZE(pg_level); i++)
for (j = 0; j < ARRAY_SIZE(pte_bits); j++)
pg_level[i].mask |= pte_bits[j].mask;
--
2.20.1