From: Palmer Dabbelt <[email protected]>
This triggers -Wempty-body, which will cause the next statement (eventually
create_pmd_mapping) to be dropped. Both of these were introduced by the same
commit. This is safe for the reporting config (which is 32-bit), but IIUC
could result in breakages for 64-bit configs without 4/5 level paging like the
XIP configs.
Reported-by: kernel test robot <[email protected]>
Fixes: 677b9eb8810e ("riscv: mm: Prepare pt_ops helper functions for sv57")
Signed-off-by: Palmer Dabbelt <[email protected]>
---
Might be better to define these to functions that are empty, but that's
slightly different than just fixing the commit/warning in question.
---
arch/riscv/mm/init.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 9535bea8688c..637916857c4d 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -798,13 +798,15 @@ static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
PGDIR_SIZE,
IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL);
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled) {
create_p4d_mapping(early_dtb_p4d, DTB_EARLY_BASE_VA,
(uintptr_t)early_dtb_pud, P4D_SIZE, PAGE_TABLE);
+ }
- if (pgtable_l4_enabled)
+ if (pgtable_l4_enabled) {
create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA,
(uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE);
+ }
if (IS_ENABLED(CONFIG_64BIT)) {
create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
--
2.34.1
Hi,
On 4/19/22 12:48, Palmer Dabbelt wrote:
> From: Palmer Dabbelt <[email protected]>
>
> This triggers -Wempty-body, which will cause the next statement (eventually
> create_pmd_mapping) to be dropped. Both of these were introduced by the same
> commit. This is safe for the reporting config (which is 32-bit), but IIUC
> could result in breakages for 64-bit configs without 4/5 level paging like the
> XIP configs.
>
> Reported-by: kernel test robot <[email protected]>
> Fixes: 677b9eb8810e ("riscv: mm: Prepare pt_ops helper functions for sv57")
> Signed-off-by: Palmer Dabbelt <[email protected]>
> ---
> Might be better to define these to functions that are empty, but that's
> slightly different than just fixing the commit/warning in question.
Yes, we usually fix this type of problem by changing these to have empty bodies:
#else
...
#define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot)
#define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot)
#endif /* __PAGETABLE_PMD_FOLDED */
etc.
> ---
> arch/riscv/mm/init.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 9535bea8688c..637916857c4d 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -798,13 +798,15 @@ static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
> PGDIR_SIZE,
> IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL);
>
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled) {
> create_p4d_mapping(early_dtb_p4d, DTB_EARLY_BASE_VA,
> (uintptr_t)early_dtb_pud, P4D_SIZE, PAGE_TABLE);
> + }
>
> - if (pgtable_l4_enabled)
> + if (pgtable_l4_enabled) {
> create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA,
> (uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE);
> + }
>
> if (IS_ENABLED(CONFIG_64BIT)) {
> create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
--
~Randy
On Tue, 19 Apr 2022 13:38:42 PDT (-0700), [email protected] wrote:
> Hi,
>
> On 4/19/22 12:48, Palmer Dabbelt wrote:
>> From: Palmer Dabbelt <[email protected]>
>>
>> This triggers -Wempty-body, which will cause the next statement (eventually
>> create_pmd_mapping) to be dropped. Both of these were introduced by the same
>> commit. This is safe for the reporting config (which is 32-bit), but IIUC
>> could result in breakages for 64-bit configs without 4/5 level paging like the
>> XIP configs.
>>
>> Reported-by: kernel test robot <[email protected]>
>> Fixes: 677b9eb8810e ("riscv: mm: Prepare pt_ops helper functions for sv57")
>> Signed-off-by: Palmer Dabbelt <[email protected]>
>> ---
>> Might be better to define these to functions that are empty, but that's
>> slightly different than just fixing the commit/warning in question.
>
> Yes, we usually fix this type of problem by changing these to have empty bodies:
>
> #else
> ...
> #define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot)
> #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot)
> #endif /* __PAGETABLE_PMD_FOLDED */
>
> etc.
Ya, that's the right way to do it -- not sure why I was being lazy here.
Turns out there was a bunch of other XIP breakage, I sent a v2 that's a
whole series.
Thanks!
>
>> ---
>> arch/riscv/mm/init.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
>> index 9535bea8688c..637916857c4d 100644
>> --- a/arch/riscv/mm/init.c
>> +++ b/arch/riscv/mm/init.c
>> @@ -798,13 +798,15 @@ static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
>> PGDIR_SIZE,
>> IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL);
>>
>> - if (pgtable_l5_enabled)
>> + if (pgtable_l5_enabled) {
>> create_p4d_mapping(early_dtb_p4d, DTB_EARLY_BASE_VA,
>> (uintptr_t)early_dtb_pud, P4D_SIZE, PAGE_TABLE);
>> + }
>>
>> - if (pgtable_l4_enabled)
>> + if (pgtable_l4_enabled) {
>> create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA,
>> (uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE);
>> + }
>>
>> if (IS_ENABLED(CONFIG_64BIT)) {
>> create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,