6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
commit 5f449e245e5b0d9d63eef6c8968fbdc3a8594407 upstream.
In COMPAT mode, the STACK_TOP is DEFAULT_MAP_WINDOW (0x80000000), but
the TASK_SIZE is 0x7fff000. When the user stack is upon 0x7fff000, it
will cause a user segment fault. Sometimes, it would cause boot
failure when the whole rootfs is rv32.
Freeing unused kernel image (initmem) memory: 2236K
Run /sbin/init as init process
Starting init: /sbin/init exists but couldn't execute it (error -14)
Run /etc/init as init process
...
Increase the TASK_SIZE to cover STACK_TOP.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
Signed-off-by: Guo Ren <guoren@xxxxxxxxxx>
Reviewed-by: Leonardo Bras <leobras@xxxxxxxxxx>
Reviewed-by: Charlie Jenkins <charlie@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231222115703.2404036-2-guoren@xxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/riscv/include/asm/pgtable.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -880,7 +880,7 @@ static inline pte_t pte_swp_clear_exclus
#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_32 (_AC(0x80000000, UL))
#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
TASK_SIZE_32 : TASK_SIZE_64)
#else
