From: bellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162>
Date: Wed, 14 May 2003 19:01:56 +0000 (+0000)
Subject: pread/pwrite syscalls - use page_unprotect_range() in vital cases to avoid problems... 
X-Git-Tag: release_0_9_0-iwjtag~2230
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=206f0fa7598242e3e3b742e72d4743e9ea4eefd0;p=qemu-xen-4.3-testing.git

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
---

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index ac7a11192..34599d0f0 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;