pread/pwrite syscalls - use page_unprotect_range() in vital cases to avoid problems if the kernel writes data in protected page (needed for self-modifying code support)

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@164 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 6 insertions, 2 deletions

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index ac7a11192b..34599d0f09 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -1137,6 +1137,7 @@ long do_syscall(void *cpu_env, int num, long arg1, long arg2, long arg3,
         ret = 0; /* avoid warning */
         break;
     case TARGET_NR_read:
+        page_unprotect_range((void *)arg2, arg3);
         ret = get_errno(read(arg1, (void *)arg2, arg3));
         break;
     case TARGET_NR_write:
@@ -2191,9 +2192,12 @@ long do_syscall(void *cpu_env, int num, long arg1, long arg2, long arg3,
     case TARGET_NR_prctl:
         goto unimplemented;
     case TARGET_NR_pread:
-        goto unimplemented;
+        page_unprotect_range((void *)arg2, arg3);
+        ret = get_errno(pread(arg1, (void *)arg2, arg3, arg4));
+        break;
     case TARGET_NR_pwrite:
-        goto unimplemented;
+        ret = get_errno(pwrite(arg1, (void *)arg2, arg3, arg4));
+        break;
     case TARGET_NR_chown:
         ret = get_errno(chown((const char *)arg1, arg2, arg3));
         break;