- Update to 2.6.25-rc3.

[linux-flexiantxendom0-3.2.10.git] / arch / um / sys-x86_64 / syscall_table.c

diff --git a/arch/um/sys-x86_64/syscall_table.c b/arch/um/sys-x86_64/syscall_table.c
index 71b2ae4..c128eb8 100644 (file)
--- a/arch/um/sys-x86_64/syscall_table.c
+++ b/arch/um/sys-x86_64/syscall_table.c
@@ -1,5 +1,7 @@
-/* System call table for UML/x86-64, copied from arch/x86_64/kernel/syscall.c
- * with some changes for UML. */
+/*
+ * System call table for UML/x86-64, copied from arch/x86_64/kernel/syscall.c
+ * with some changes for UML.
+ */
 
 #include <linux/linkage.h>
 #include <linux/sys.h>
@@ -8,22 +10,26 @@
 
 #define __NO_STUBS
 
-/* Below you can see, in terms of #define's, the differences between the x86-64
- * and the UML syscall table. */
+/*
+ * Below you can see, in terms of #define's, the differences between the x86-64
+ * and the UML syscall table.
+ */
 
 /* Not going to be implemented by UML, since we have no hardware. */
 #define stub_iopl sys_ni_syscall
 #define sys_ioperm sys_ni_syscall
 
-/* The UML TLS problem. Note that x86_64 does not implement this, so the below
- * is needed only for the ia32 compatibility. */
-/*#define sys_set_thread_area sys_ni_syscall
-#define sys_get_thread_area sys_ni_syscall*/
+/*
+ * The UML TLS problem. Note that x86_64 does not implement this, so the below
+ * is needed only for the ia32 compatibility.
+ */
 
 /* On UML we call it this way ("old" means it's not mmap2) */
 #define sys_mmap old_mmap
-/* On x86-64 sys_uname is actually sys_newuname plus a compatibility trick.
- * See arch/x86_64/kernel/sys_x86_64.c */
+/*
+ * On x86-64 sys_uname is actually sys_newuname plus a compatibility trick.
+ * See arch/x86_64/kernel/sys_x86_64.c
+ */
 #define sys_uname sys_uname64
 
 #define stub_clone sys_clone
@@ -46,8 +52,19 @@ typedef void (*sys_call_ptr_t)(void);
 
 extern void sys_ni_syscall(void);
 
-sys_call_ptr_t sys_call_table[UM_NR_syscall_max+1] __cacheline_aligned = {
-       /* Smells like a like a compiler bug -- it doesn't work when the & below is removed. */
-       [0 ... UM_NR_syscall_max] = &sys_ni_syscall,
+/*
+ * We used to have a trick here which made sure that holes in the
+ * x86_64 table were filled in with sys_ni_syscall, but a comment in
+ * unistd_64.h says that holes aren't allowed, so the trick was
+ * removed.
+ * The trick looked like this
+ *     [0 ... UM_NR_syscall_max] = &sys_ni_syscall
+ * before including unistd_64.h - the later initializations overwrote
+ * the sys_ni_syscall filler.
+ */
+
+sys_call_ptr_t sys_call_table[] __cacheline_aligned = {
 #include <asm-x86/unistd_64.h>
 };
+
+int syscall_table_size = sizeof(sys_call_table);