accel/tcg: Call tb_invalidate_phys_page for PAGE_RESET

When PAGE_RESET is set, we are replacing pages with new
content, which means that we need to invalidate existing
cached data, such as TranslationBlocks.  Perform the
reset invalidate while we're doing other invalidates,
which allows us to remove the separate invalidates from
the user-only mmap/munmap/mprotect routines.

In addition, restrict invalidation to PAGE_EXEC pages.
Since cdf713085131, we have validated PAGE_EXEC is present
before translation, which means we can assume that if the
bit is not present, there are no translations to invalidate.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

3 files changed, 11 insertions, 14 deletions

diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 8d5233fa9e..478301f227 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -1352,7 +1352,7 @@ int page_get_flags(target_ulong address)
 void page_set_flags(target_ulong start, target_ulong end, int flags)
 {
     target_ulong addr, len;
-    bool reset_target_data;
+    bool reset;
 
     /* This function should never be called with addresses outside the
        guest address space.  If this assert fires, it probably indicates
@@ -1369,7 +1369,7 @@ void page_set_flags(target_ulong start, target_ulong end, int flags)
     if (flags & PAGE_WRITE) {
         flags |= PAGE_WRITE_ORG;
     }
-    reset_target_data = !(flags & PAGE_VALID) || (flags & PAGE_RESET);
+    reset = !(flags & PAGE_VALID) || (flags & PAGE_RESET);
     flags &= ~PAGE_RESET;
 
     for (addr = start, len = end - start;
@@ -1377,14 +1377,17 @@ void page_set_flags(target_ulong start, target_ulong end, int flags)
          len -= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) {
         PageDesc *p = page_find_alloc(addr >> TARGET_PAGE_BITS, true);
 
-        /* If the write protection bit is set, then we invalidate
-           the code inside.  */
-        if (!(p->flags & PAGE_WRITE) &&
-            (flags & PAGE_WRITE) &&
-            p->first_tb) {
+        /*
+         * If the page was executable, but is reset, or is no longer
+         * executable, or has become writable, then invalidate any code.
+         */
+        if ((p->flags & PAGE_EXEC)
+            && (reset ||
+                !(flags & PAGE_EXEC) ||
+                (flags & ~p->flags & PAGE_WRITE))) {
             tb_invalidate_phys_page(addr);
         }
-        if (reset_target_data) {
+        if (reset) {
             g_free(p->target_data);
             p->target_data = NULL;
             p->flags = flags;
diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
index e54e26de17..d6c5a344c9 100644
--- a/bsd-user/mmap.c
+++ b/bsd-user/mmap.c
@@ -663,7 +663,6 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
     page_dump(stdout);
     printf("\n");
 #endif
-    tb_invalidate_phys_range(start, start + len);
     mmap_unlock();
     return start;
 fail:
@@ -769,7 +768,6 @@ int target_munmap(abi_ulong start, abi_ulong len)
 
     if (ret == 0) {
         page_set_flags(start, start + len, 0);
-        tb_invalidate_phys_range(start, start + len);
     }
     mmap_unlock();
     return ret;
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 28f3bc85ed..10f5079331 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -182,7 +182,6 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
     }
 
     page_set_flags(start, start + len, page_flags);
-    tb_invalidate_phys_range(start, start + len);
     ret = 0;
 
 error:
@@ -662,7 +661,6 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
             qemu_log_unlock(f);
         }
     }
-    tb_invalidate_phys_range(start, start + len);
     mmap_unlock();
     return start;
 fail:
@@ -766,7 +764,6 @@ int target_munmap(abi_ulong start, abi_ulong len)
 
     if (ret == 0) {
         page_set_flags(start, start + len, 0);
-        tb_invalidate_phys_range(start, start + len);
     }
     mmap_unlock();
     return ret;
@@ -856,7 +853,6 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
         page_set_flags(new_addr, new_addr + new_size,
                        prot | PAGE_VALID | PAGE_RESET);
     }
-    tb_invalidate_phys_range(new_addr, new_addr + new_size);
     mmap_unlock();
     return new_addr;
 }