8 files changed, 165 insertions, 6 deletions

diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index 1184f6eea98b..ea77a42c5f8c 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -368,4 +368,8 @@ extern const char *__elf_platform;
 #define ELF_ET_DYN_BASE         (TASK_SIZE / 3 * 2)
 #endif
 
+#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
+struct linux_binprm;
+extern int arch_setup_additional_pages(struct linux_binprm *bprm,
+                                       int uses_interp);
 #endif /* _ASM_ELF_H */
diff --git a/arch/mips/include/asm/mmu.h b/arch/mips/include/asm/mmu.h
index 4063edd79623..c436138945a8 100644
--- a/arch/mips/include/asm/mmu.h
+++ b/arch/mips/include/asm/mmu.h
@@ -1,6 +1,9 @@
 #ifndef __ASM_MMU_H
 #define __ASM_MMU_H
 
-typedef unsigned long mm_context_t[NR_CPUS];
+typedef struct {
+        unsigned long asid[NR_CPUS];
+        void *vdso;
+} mm_context_t;
 
 #endif /* __ASM_MMU_H */
diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h
index 145bb81ccaa5..d9592733a7ba 100644
--- a/arch/mips/include/asm/mmu_context.h
+++ b/arch/mips/include/asm/mmu_context.h
@@ -104,7 +104,7 @@ extern unsigned long smtc_asid_mask;
 
 #endif
 
-#define cpu_context(cpu, mm)    ((mm)->context[cpu])
+#define cpu_context(cpu, mm)    ((mm)->context.asid[cpu])
 #define cpu_asid(cpu, mm)       (cpu_context((cpu), (mm)) & ASID_MASK)
 #define asid_cache(cpu)         (cpu_data[cpu].asid_cache)
 
diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h
index 087a8884ef06..ab387910009a 100644
--- a/arch/mips/include/asm/processor.h
+++ b/arch/mips/include/asm/processor.h
@@ -33,13 +33,19 @@ extern void (*cpu_wait)(void);
 
 extern unsigned int vced_count, vcei_count;
 
+/*
+ * A special page (the vdso) is mapped into all processes at the very
+ * top of the virtual memory space.
+ */
+#define SPECIAL_PAGES_SIZE PAGE_SIZE
+
 #ifdef CONFIG_32BIT
 /*
  * User space process size: 2GB. This is hardcoded into a few places,
  * so don't change it unless you know what you are doing.
  */
 #define TASK_SIZE       0x7fff8000UL
-#define STACK_TOP       TASK_SIZE
+#define STACK_TOP       ((TASK_SIZE & PAGE_MASK) - SPECIAL_PAGES_SIZE)
 
 /*
  * This decides where the kernel will search for a free chunk of vm
@@ -59,7 +65,8 @@ extern unsigned int vced_count, vcei_count;
 #define TASK_SIZE32     0x7fff8000UL
 #define TASK_SIZE       0x10000000000UL
 #define STACK_TOP       \
-      (test_thread_flag(TIF_32BIT_ADDR) ? TASK_SIZE32 : TASK_SIZE)
+        (((test_thread_flag(TIF_32BIT_ADDR) ?                           \
+           TASK_SIZE32 : TASK_SIZE) & PAGE_MASK) - SPECIAL_PAGES_SIZE)
 
 /*
  * This decides where the kernel will search for a free chunk of vm
diff --git a/arch/mips/include/asm/vdso.h b/arch/mips/include/asm/vdso.h
new file mode 100644
index 000000000000..cca56aa40ff4
--- /dev/null
+++ b/arch/mips/include/asm/vdso.h
@@ -0,0 +1,29 @@
+/*
+ * 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 Cavium Networks
+ */
+
+#ifndef __ASM_VDSO_H
+#define __ASM_VDSO_H
+
+#include <linux/types.h>
+
+
+#ifdef CONFIG_32BIT
+struct mips_vdso {
+        u32 signal_trampoline[2];
+        u32 rt_signal_trampoline[2];
+};
+#else  /* !CONFIG_32BIT */
+struct mips_vdso {
+        u32 o32_signal_trampoline[2];
+        u32 o32_rt_signal_trampoline[2];
+        u32 rt_signal_trampoline[2];
+        u32 n32_rt_signal_trampoline[2];
+};
+#endif /* CONFIG_32BIT */
+
+#endif /* __ASM_VDSO_H */
diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index ef20957ca14b..7a6ac501cbb5 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -6,7 +6,7 @@ extra-y		:= head.o init_task.o vmlinux.lds
 
 obj-y           += cpu-probe.o branch.o entry.o genex.o irq.o process.o \
                    ptrace.o reset.o setup.o signal.o syscall.o \
-                   time.o topology.o traps.o unaligned.o watch.o
+                   time.o topology.o traps.o unaligned.o watch.o vdso.o
 
 ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_ftrace.o = -pg
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index 9587abc67f35..dd81b0f87518 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -79,7 +79,11 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
         int do_color_align;
         unsigned long task_size;
 
-        task_size = STACK_TOP;
+#ifdef CONFIG_32BIT
+        task_size = TASK_SIZE;
+#else /* Must be CONFIG_64BIT*/
+        task_size = test_thread_flag(TIF_32BIT_ADDR) ? TASK_SIZE32 : TASK_SIZE;
+#endif
 
         if (len > task_size)
                 return -ENOMEM;
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;
+}