accel/tcg: Pass last not end to page_reset_target_data

Pass the address of the last byte to be changed, rather than
the first address past the last byte.  This avoids overflow
when the last page of the address space is involved.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
index 035f8096b29a8336b58acdfdb269e73f4d54bd64..20b6fc2f6ef3b18fe6ab5359b8f6515b2428ba1b 100644 (file)
--- a/accel/tcg/user-exec.c
+++ b/accel/tcg/user-exec.c
@@ -508,7 +508,7 @@ void page_set_flags(target_ulong start, target_ulong last, int flags)
     }
 
     if (!flags || reset) {
-        page_reset_target_data(start, last + 1);
+        page_reset_target_data(start, last);
         inval_tb |= pageflags_unset(start, last);
     }
     if (flags) {
@@ -814,15 +814,14 @@ typedef struct TargetPageDataNode {
 
 static IntervalTreeRoot targetdata_root;
 
-void page_reset_target_data(target_ulong start, target_ulong end)
+void page_reset_target_data(target_ulong start, target_ulong last)
 {
     IntervalTreeNode *n, *next;
-    target_ulong last;
 
     assert_memory_lock();
 
-    start = start & TARGET_PAGE_MASK;
-    last = TARGET_PAGE_ALIGN(end) - 1;
+    start &= TARGET_PAGE_MASK;
+    last |= ~TARGET_PAGE_MASK;
 
     for (n = interval_tree_iter_first(&targetdata_root, start, last),
          next = n ? interval_tree_iter_next(n, start, last) : NULL;
@@ -885,7 +884,7 @@ void *page_get_target_data(target_ulong address)
     return t->data[(page - region) >> TARGET_PAGE_BITS];
 }
 #else
-void page_reset_target_data(target_ulong start, target_ulong end) { }
+void page_reset_target_data(target_ulong start, target_ulong last) { }
 #endif /* TARGET_PAGE_DATA_SIZE */
 
 /* The softmmu versions of these helpers are in cputlb.c.  */

diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index a2662b1e83d9144689f3c653b4c73028034089c3..64cb62dc549e7cac526d15e508d0470c0fdb6a57 100644 (file)
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -277,7 +277,7 @@ int walk_memory_regions(void *, walk_memory_regions_fn);
 
 int page_get_flags(target_ulong address);
 void page_set_flags(target_ulong start, target_ulong last, int flags);
-void page_reset_target_data(target_ulong start, target_ulong end);
+void page_reset_target_data(target_ulong start, target_ulong last);
 int page_check_range(target_ulong start, target_ulong len, int flags);
 
 /**

diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 1d07ff5d2c9fc312eb1a74e44eb1ae00653d47f9..995146f60da76e19249260c5631b20f21095354a 100644 (file)
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -946,7 +946,7 @@ abi_long target_madvise(abi_ulong start, abi_ulong len_in, int advice)
         if (can_passthrough_madvise(start, end)) {
             ret = get_errno(madvise(g2h_untagged(start), len, advice));
             if ((advice == MADV_DONTNEED) && (ret == 0)) {
-                page_reset_target_data(start, start + len);
+                page_reset_target_data(start, start + len - 1);
             }
         }
     }