From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> Make TASK_SIZE from const to dynamic detect TIF_32BIT flag function. Refer to arm64 to implement DEFAULT_MAP_WINDOW_64 for efi-stub. Limit 32-bit compatible process in 0-2GB virtual address range (which is enough for real scenarios), because it could avoid address sign extend problem when 32-bit enter 64-bit and ease software design. The standard 32-bit TASK_SIZE is 0x9dc00000:FIXADDR_START, and compared to a compatible 32-bit, it increases 476MB for the application's virtual address. Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> Signed-off-by: Guo Ren <guoren@xxxxxxxxxx> Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx> --- arch/riscv/include/asm/pgtable.h | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 7e949f25c933..f0d125ea3ceb 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -704,8 +704,17 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, * 63–48 all equal to bit 47, or else a page-fault exception will occur." */ #ifdef CONFIG_64BIT -#define TASK_SIZE (PGDIR_SIZE * PTRS_PER_PGD / 2) -#define TASK_SIZE_MIN (PGDIR_SIZE_L3 * PTRS_PER_PGD / 2) +#define TASK_SIZE_64 (PGDIR_SIZE * PTRS_PER_PGD / 2) +#define TASK_SIZE_MIN (PGDIR_SIZE_L3 * PTRS_PER_PGD / 2) + +#ifdef CONFIG_COMPAT +#define TASK_SIZE_32 (_AC(0x80000000, UL) - PAGE_SIZE) +#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \ + TASK_SIZE_32 : TASK_SIZE_64) +#else +#define TASK_SIZE TASK_SIZE_64 +#endif + #else #define TASK_SIZE FIXADDR_START #define TASK_SIZE_MIN TASK_SIZE -- 2.25.1
