[rt-smart] handling kernel from accessing unmapped user stack (#6957)

[rt-smart] handling kernel from accessing unmapped user stack

2 files changed, 17 insertions, 4 deletions

diff --git a/components/lwp/arch/risc-v/rv64/lwp_gcc.S b/components/lwp/arch/risc-v/rv64/lwp_gcc.S
index c54726bc45..3977553dbf 100644
--- a/components/lwp/arch/risc-v/rv64/lwp_gcc.S
+++ b/components/lwp/arch/risc-v/rv64/lwp_gcc.S
@@ -121,6 +121,16 @@ arch_signal_quit:
  * routine in user stack
  */
 user_do_signal:
+    /* prefetch ustack to avoid corrupted status in RESTORE/STORE pair below */
+    LOAD t0, FRAME_OFF_SP(sp)
+    addi t1, t0, -CTX_REG_NR * REGBYTES
+    LOAD t2, (t0)
+    li t3, -0x1000
+1:
+    add t0, t0, t3
+    LOAD t2, (t0)
+    bgt t0, t1, 1b
+
     /** restore and backup kernel sp carefully to avoid leaking */
     addi t0, sp, CTX_REG_NR * REGBYTES
     csrw sscratch, t0
diff --git a/components/lwp/lwp_user_mm.c b/components/lwp/lwp_user_mm.c
index 3844a3b189..edda62632d 100644
--- a/components/lwp/lwp_user_mm.c
+++ b/components/lwp/lwp_user_mm.c
@@ -560,9 +560,12 @@ int lwp_user_accessable(void *addr, size_t size)
             len = size;
         }
         tmp_addr = lwp_v2p(lwp, addr_start);
-        if (!tmp_addr)
+        if (tmp_addr == ARCH_MAP_FAILED)
         {
-            return 0;
+            if ((rt_ubase_t)addr_start >= USER_STACK_VSTART && (rt_ubase_t)addr_start < USER_STACK_VEND)
+                tmp_addr = *(void **)addr_start;
+            else
+                return 0;
         }
         addr_start = (void *)((char *)addr_start + len);
         size -= len;
@@ -596,7 +599,7 @@ size_t lwp_data_get(struct rt_lwp *lwp, void *dst, void *src, size_t size)
             len = size;
         }
         tmp_src = lwp_v2p(lwp, addr_start);
-        if (!tmp_src)
+        if (tmp_src == ARCH_MAP_FAILED)
         {
             break;
         }
@@ -636,7 +639,7 @@ size_t lwp_data_put(struct rt_lwp *lwp, void *dst, void *src, size_t size)
             len = size;
         }
         tmp_dst = lwp_v2p(lwp, addr_start);
-        if (!tmp_dst)
+        if (tmp_dst == ARCH_MAP_FAILED)
         {
             break;
         }