[Qemu-devel] Re: [PATCH] linux-user readlinkat() syscall

[Thayne Harbaugh <thayne@c2.net>]

[-- Attachment #1: Type: text/plain, Size: 54 bytes --]

This patch adds the readlinkat syscall to linux-user.

[-- Attachment #2: 32_readlinkat.patch --]
[-- Type: text/x-patch, Size: 2372 bytes --]

Index: qemu/linux-user/syscall.c
===================================================================
--- qemu.orig/linux-user/syscall.c	2007-09-19 06:26:51.000000000 -0600
+++ qemu/linux-user/syscall.c	2007-09-19 06:27:29.000000000 -0600
@@ -160,6 +160,7 @@
 #define __NR_sys_mkdirat __NR_mkdirat
 #define __NR_sys_mknodat __NR_mknodat
 #define __NR_sys_openat __NR_openat
+#define __NR_sys_readlinkat __NR_readlinkat
 #define __NR_sys_renameat __NR_renameat
 #define __NR_sys_rt_sigqueueinfo __NR_rt_sigqueueinfo
 #define __NR_sys_symlinkat __NR_symlinkat
@@ -210,6 +211,10 @@
 #if defined(TARGET_NR_openat) && defined(__NR_openat)
 _syscall4(int,sys_openat,int,dirfd,const char *,pathname,int,flags,mode_t,mode)
 #endif
+#if defined(TARGET_NR_readlinkat) && defined(__NR_readlinkat)
+_syscall4(int,sys_readlinkat,int,dirfd,const char *,pathname,
+          char *,buf,size_t,bufsize)
+#endif
 #if defined(TARGET_NR_renameat) && defined(__NR_renameat)
 _syscall4(int,sys_renameat,int,olddirfd,const char *,oldpath,
           int,newdirfd,const char *,newpath)
@@ -3584,6 +3589,28 @@
             unlock_user(p, arg1, 0);
         }
         break;
+#if defined(TARGET_NR_readlinkat) && defined(__NR_readlinkat)
+    case TARGET_NR_readlinkat:
+        if (!arg2 || !arg3) {
+            ret = -EFAULT;
+            goto fail;
+	}
+        {
+            void *p2 = NULL;
+            p  = lock_user_string(arg2);
+            p2 = lock_user(arg3, arg4, 0);
+            if (!access_ok(VERIFY_READ, p, 1)
+                || !access_ok(VERIFY_READ, p2, 1))
+        	ret = -EFAULT;
+            else
+                ret = get_errno(sys_readlinkat(arg1, path(p), p2, arg4));
+            if (p2)
+                unlock_user(p2, arg3, ret);
+            if (p)
+                unlock_user(p, arg2, 0);
+        }
+        break;
+#endif
 #ifdef TARGET_NR_uselib
     case TARGET_NR_uselib:
         goto unimplemented;
Index: qemu/linux-user/arm/syscall_nr.h
===================================================================
--- qemu.orig/linux-user/arm/syscall_nr.h	2007-09-19 06:26:21.000000000 -0600
+++ qemu/linux-user/arm/syscall_nr.h	2007-09-19 06:26:57.000000000 -0600
@@ -334,4 +334,5 @@
 #define TARGET_NR_renameat			329
 #define TARGET_NR_linkat			330
 #define TARGET_NR_symlinkat			331
+#define TARGET_NR_readlinkat			332
 #define TARGET_NR_utimensat			348