From: Jisheng Zhang jszhang@kernel.org
[ Upstream commit b690e266dae2f85f4dfea21fa6a05e3500a51054 ]
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 jszhang@kernel.org Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202306080034.SLiCiOMn-lkp@intel.com/ Link: https://lore.kernel.org/r/20230709171036.1906-1-jszhang@kernel.org Signed-off-by: Palmer Dabbelt palmer@rivosinc.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 f8bfbe983517c..d7115acab3501 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -843,7 +843,7 @@ 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,