[PATCH v2 24/29] tcg: Do not set guard pages in the rx buffer

[Richard Henderson]

We only need guard pages in the rw buffer to avoid buffer overruns.
Let the rx buffer keep large pages all the way through.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/region.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/tcg/region.c b/tcg/region.c
index 994c083343..27a7e35c8e 100644
--- a/tcg/region.c
+++ b/tcg/region.c
@@ -839,7 +839,6 @@ void tcg_region_init(size_t tb_size, int splitwx, unsigned 
max_cpus)
     size_t page_size;
     size_t region_size;
     size_t i;
-    uintptr_t splitwx_diff;
     int have_prot;
 
     have_prot = alloc_code_gen_buffer(size_code_gen_buffer(tb_size),
@@ -881,8 +880,7 @@ void tcg_region_init(size_t tb_size, int splitwx, unsigned 
max_cpus)
     /* init the region struct */
     qemu_mutex_init(&region.lock);
 
-    /* set guard pages */
-    splitwx_diff = tcg_splitwx_diff;
+    /* Set guard pages.  No need to do this for the rx_buf, only the rw_buf. */
     for (i = 0; i < region.n; i++) {
         void *start, *end;
         int rc;
@@ -890,10 +888,6 @@ void tcg_region_init(size_t tb_size, int splitwx, unsigned 
max_cpus)
         tcg_region_bounds(i, &start, &end);
         rc = qemu_mprotect_none(end, page_size);
         g_assert(!rc);
-        if (splitwx_diff) {
-            rc = qemu_mprotect_none(end + splitwx_diff, page_size);
-            g_assert(!rc);
-        }
     }
 
     tcg_region_trees_init();
-- 
2.25.1