[PATCH -fixes] riscv: Fix comment regarding kernel mapping overlapping with IS_ERR_VALUE

[PATCH -fixes] riscv: Fix comment regarding kernel mapping overlapping with IS_ERR_VALUE

[Alexandre Ghiti]

The current comment states that we check if the 64-bit kernel mapping
overlaps with the last 4K of the address space that is reserved to
error values in create_kernel_page_table, which is not the case since it
is done in setup_vm. But anyway, remove the reference to any function
and simply note that in 64-bit kernel, the check should be done as soon
as the kernel mapping base address is known.

Fixes: db6b84a368b4 ("riscv: Make sure the kernel mapping does not
overlap with IS_ERR_VALUE")
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
---
 arch/riscv/mm/init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index a14bf3910eec..79a2e02924e4 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -191,7 +191,7 @@ static void __init setup_bootmem(void)
 	 * if end of dram is equal to maximum addressable memory.  For 64-bit
 	 * kernel, this problem can't happen here as the end of the virtual
 	 * address space is occupied by the kernel mapping then this check must
-	 * be done in create_kernel_page_table.
+	 * be done as soon as the kernel mapping base address is determined.
 	 */
 	max_mapped_addr = __pa(~(ulong)0);
 	if (max_mapped_addr == (dram_end - 1))
-- 
2.30.2

Re: [PATCH -fixes] riscv: Fix comment regarding kernel mapping overlapping with IS_ERR_VALUE

[Palmer Dabbelt]

On Sun, 25 Jul 2021 22:42:54 PDT (-0700), alex@ghiti.fr wrote:
> The current comment states that we check if the 64-bit kernel mapping
> overlaps with the last 4K of the address space that is reserved to
> error values in create_kernel_page_table, which is not the case since it
> is done in setup_vm. But anyway, remove the reference to any function
> and simply note that in 64-bit kernel, the check should be done as soon
> as the kernel mapping base address is known.
>
> Fixes: db6b84a368b4 ("riscv: Make sure the kernel mapping does not
> overlap with IS_ERR_VALUE")
> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
> ---
>  arch/riscv/mm/init.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index a14bf3910eec..79a2e02924e4 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -191,7 +191,7 @@ static void __init setup_bootmem(void)
>  	 * if end of dram is equal to maximum addressable memory.  For 64-bit
>  	 * kernel, this problem can't happen here as the end of the virtual
>  	 * address space is occupied by the kernel mapping then this check must
> -	 * be done in create_kernel_page_table.
> +	 * be done as soon as the kernel mapping base address is determined.
>  	 */
>  	max_mapped_addr = __pa(~(ulong)0);
>  	if (max_mapped_addr == (dram_end - 1))

Thanks, this is on fixes.