diff options
| author | Guo Ren <guoren@linux.alibaba.com> | 2022-04-05 15:13:04 +0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-04-26 13:36:18 -0700 |
| commit | 01abdfeac81b5f56062d0a78f2cdc805db937a75 (patch) | |
| tree | 1ee65759a7a41655c34ffe005bc3c256e33532b2 | |
| parent | 06d0e3723647610936660c3c2a144c6243367c3c (diff) | |
riscv: compat: Support TASK_SIZE for compat mode
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@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20220405071314.3225832-11-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| -rw-r--r-- | arch/riscv/include/asm/pgtable.h | 13 | ||||
| -rw-r--r-- | arch/riscv/include/asm/processor.h | 6 |
2 files changed, 16 insertions, 3 deletions
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 046b44225623..e32d75fef068 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -707,8 +707,17 @@ 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 diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index 0749924d9e55..21c8072dce17 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -19,7 +19,11 @@ #define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3) #define STACK_TOP TASK_SIZE -#define STACK_TOP_MAX STACK_TOP +#ifdef CONFIG_64BIT +#define STACK_TOP_MAX TASK_SIZE_64 +#else +#define STACK_TOP_MAX TASK_SIZE +#endif #define STACK_ALIGN 16 #ifndef __ASSEMBLY__ |