lkp reports below sparse warning when building for RV32:
arch/riscv/mm/init.c:1204:48: sparse: warning: cast truncates bits from
constant value (100000000 becomes 0)
IMO, the reason we didn't see this truncates bug in real world is "0"
means MEMBLOCK_ALLOC_ACCESSIBLE in memblock and there's no RV32 HW
with more than 4GB memory.
Fix it anyway to make sparse happy.
Fixes: decf89f86ecd ("riscv: try to allocate crashkern region from 32bit addressible memory")
Signed-off-by: Jisheng Zhang <[email protected]>
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
---
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 70fb31960b63..9ce504737d18 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -1346,7 +1346,7 @@ static void __init reserve_crashkernel(void)
*/
crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
search_start,
- min(search_end, (unsigned long) SZ_4G));
+ min(search_end, (unsigned long)(SZ_4G - 1)));
if (crash_base == 0) {
/* Try again without restricting region to 32bit addressible memory */
crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
--
2.40.1
On Mon, 10 Jul 2023 01:10:36 +0800, Jisheng Zhang wrote:
> lkp reports below sparse warning when building for RV32:
> arch/riscv/mm/init.c:1204:48: sparse: warning: cast truncates bits from
> constant value (100000000 becomes 0)
>
> IMO, the reason we didn't see this truncates bug in real world is "0"
> means MEMBLOCK_ALLOC_ACCESSIBLE in memblock and there's no RV32 HW
> with more than 4GB memory.
>
> [...]
Applied, thanks!
[1/1] riscv: mm: fix truncates issue on RV32
https://git.kernel.org/palmer/c/b690e266dae2
Best regards,
--
Palmer Dabbelt <[email protected]>
Hello:
This patch was applied to riscv/linux.git (fixes)
by Palmer Dabbelt <[email protected]>:
On Mon, 10 Jul 2023 01:10:36 +0800 you wrote:
> lkp reports below sparse warning when building for RV32:
> arch/riscv/mm/init.c:1204:48: sparse: warning: cast truncates bits from
> constant value (100000000 becomes 0)
>
> IMO, the reason we didn't see this truncates bug in real world is "0"
> means MEMBLOCK_ALLOC_ACCESSIBLE in memblock and there's no RV32 HW
> with more than 4GB memory.
>
> [...]
Here is the summary with links:
- riscv: mm: fix truncates issue on RV32
https://git.kernel.org/riscv/c/b690e266dae2
You are awesome, thank you!
--
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https://korg.docs.kernel.org/patchwork/pwbot.html