This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / um / os-Linux / elf_aux.c

diff --git a/arch/um/os-Linux/elf_aux.c b/arch/um/os-Linux/elf_aux.c
new file mode 100644 (file)
index 0000000..9aee0b6
--- /dev/null
+++ b/arch/um/os-Linux/elf_aux.c
@@ -0,0 +1,66 @@
+/*
+ *  arch/um/kernel/elf_aux.c
+ *
+ *  Scan the Elf auxiliary vector provided by the host to extract
+ *  information about vsyscall-page, etc.
+ *
+ *  Copyright (C) 2004 Fujitsu Siemens Computers GmbH
+ *  Author: Bodo Stroesser (bodo.stroesser@fujitsu-siemens.com)
+ */
+#include <elf.h>
+#include <stddef.h>
+#include "init.h"
+#include "elf_user.h"
+
+#if ELF_CLASS == ELFCLASS32
+typedef Elf32_auxv_t elf_auxv_t;
+#else
+typedef Elf64_auxv_t elf_auxv_t;
+#endif
+
+char * elf_aux_platform;
+long elf_aux_hwcap;
+
+unsigned long vsyscall_ehdr;
+unsigned long vsyscall_end;
+
+unsigned long __kernel_vsyscall;
+
+__init void scan_elf_aux( char **envp)
+{
+       long page_size = 0;
+       elf_auxv_t * auxv;
+
+       while ( *envp++ != NULL) ;
+
+       for ( auxv = (elf_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) {
+               switch ( auxv->a_type ) {
+                       case AT_SYSINFO:
+                               __kernel_vsyscall = auxv->a_un.a_val;
+                               break;
+                       case AT_SYSINFO_EHDR:
+                               vsyscall_ehdr = auxv->a_un.a_val;
+                               break;
+                       case AT_HWCAP:
+                               elf_aux_hwcap = auxv->a_un.a_val;
+                               break;
+                       case AT_PLATFORM:
+                               elf_aux_platform = auxv->a_un.a_ptr;
+                               break;
+                       case AT_PAGESZ:
+                               page_size = auxv->a_un.a_val;
+                               break;
+               }
+       }
+       if ( ! __kernel_vsyscall || ! vsyscall_ehdr ||
+            ! elf_aux_hwcap || ! elf_aux_platform ||
+            ! page_size || (vsyscall_ehdr % page_size) ) {
+               __kernel_vsyscall = 0;
+               vsyscall_ehdr = 0;
+               elf_aux_hwcap = 0;
+               elf_aux_platform = "i586";
+       }
+       else {
+               vsyscall_end = vsyscall_ehdr + page_size;
+       }
+}