1 files changed, 112 insertions, 0 deletions

diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c
new file mode 100644
index 000000000000..b773c1112b14
--- /dev/null
+++ b/arch/mips/kernel/vdso.c
@@ -0,0 +1,112 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2009, 2010 Cavium Networks, Inc.
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/binfmts.h>
+#include <linux/elf.h>
+#include <linux/vmalloc.h>
+#include <linux/unistd.h>
+
+#include <asm/vdso.h>
+#include <asm/uasm.h>
+
+/*
+ * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
+ */
+#define __NR_O32_sigreturn              4119
+#define __NR_O32_rt_sigreturn           4193
+#define __NR_N32_rt_sigreturn           6211
+
+static struct page *vdso_page;
+
+static void __init install_trampoline(u32 *tramp, unsigned int sigreturn)
+{
+        uasm_i_addiu(&tramp, 2, 0, sigreturn);  /* li v0, sigreturn */
+        uasm_i_syscall(&tramp, 0);
+}
+
+static int __init init_vdso(void)
+{
+        struct mips_vdso *vdso;
+
+        vdso_page = alloc_page(GFP_KERNEL);
+        if (!vdso_page)
+                panic("Cannot allocate vdso");
+
+        vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL);
+        if (!vdso)
+                panic("Cannot map vdso");
+        clear_page(vdso);
+
+        install_trampoline(vdso->rt_signal_trampoline, __NR_rt_sigreturn);
+#ifdef CONFIG_32BIT
+        install_trampoline(vdso->signal_trampoline, __NR_sigreturn);
+#else
+        install_trampoline(vdso->n32_rt_signal_trampoline,
+                           __NR_N32_rt_sigreturn);
+        install_trampoline(vdso->o32_signal_trampoline, __NR_O32_sigreturn);
+        install_trampoline(vdso->o32_rt_signal_trampoline,
+                           __NR_O32_rt_sigreturn);
+#endif
+
+        vunmap(vdso);
+
+        pr_notice("init_vdso successfull\n");
+
+        return 0;
+}
+device_initcall(init_vdso);
+
+static unsigned long vdso_addr(unsigned long start)
+{
+        return STACK_TOP;
+}
+
+int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+{
+        int ret;
+        unsigned long addr;
+        struct mm_struct *mm = current->mm;
+
+        down_write(&mm->mmap_sem);
+
+        addr = vdso_addr(mm->start_stack);
+
+        addr = get_unmapped_area(NULL, addr, PAGE_SIZE, 0, 0);
+        if (IS_ERR_VALUE(addr)) {
+                ret = addr;
+                goto up_fail;
+        }
+
+        ret = install_special_mapping(mm, addr, PAGE_SIZE,
+                                      VM_READ|VM_EXEC|
+                                      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
+                                      VM_ALWAYSDUMP,
+                                      &vdso_page);
+
+        if (ret)
+                goto up_fail;
+
+        mm->context.vdso = (void *)addr;
+
+up_fail:
+        up_write(&mm->mmap_sem);
+        return ret;
+}
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+        if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
+                return "[vdso]";
+        return NULL;
+}