s390/vdso: misc simple code changes

- remove unneeded includes
- move functions around
- remove obvious and/or incorrect comments
- shorten some if conditions

No functional change.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index f4e1e45..a7eed8b 100644 (file)
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -6,41 +6,41 @@
  *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
  */
 
-#include <linux/init.h>
+#include <linux/binfmts.h>
+#include <linux/compat.h>
+#include <linux/elf.h>
 #include <linux/errno.h>
-#include <linux/sched.h>
+#include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
-#include <linux/smp.h>
-#include <linux/stddef.h>
-#include <linux/unistd.h>
 #include <linux/slab.h>
-#include <linux/user.h>
-#include <linux/elf.h>
-#include <linux/security.h>
-#include <linux/memblock.h>
-#include <linux/compat.h>
-#include <linux/binfmts.h>
+#include <linux/smp.h>
 #include <vdso/datapage.h>
-#include <asm/asm-offsets.h>
-#include <asm/processor.h>
-#include <asm/mmu.h>
-#include <asm/mmu_context.h>
-#include <asm/sections.h>
 #include <asm/vdso.h>
-#include <asm/facility.h>
-#include <asm/timex.h>
 
 extern char vdso64_start[], vdso64_end[];
 static unsigned int vdso_pages;
 static struct page **vdso_pagelist;
 
-/*
- * Should the kernel map a VDSO page into processes and pass its
- * address down to glibc upon exec()?
- */
+static union {
+       struct vdso_data        data[CS_BASES];
+       u8                      page[PAGE_SIZE];
+} vdso_data_store __page_aligned_data;
+
+struct vdso_data *vdso_data = vdso_data_store.data;
+
 unsigned int __read_mostly vdso_enabled = 1;
 
+static int __init vdso_setup(char *str)
+{
+       bool enabled;
+
+       if (!kstrtobool(str, &enabled))
+               vdso_enabled = enabled;
+       return 1;
+}
+__setup("vdso=", vdso_setup);
+
 static vm_fault_t vdso_fault(const struct vm_special_mapping *sm,
                      struct vm_area_struct *vma, struct vm_fault *vmf)
 {
@@ -56,7 +56,6 @@ static int vdso_mremap(const struct vm_special_mapping *sm,
                       struct vm_area_struct *vma)
 {
        current->mm->context.vdso_base = vma->vm_start;
-
        return 0;
 }
 
@@ -66,25 +65,6 @@ static const struct vm_special_mapping vdso_mapping = {
        .mremap = vdso_mremap,
 };
 
-static int __init vdso_setup(char *str)
-{
-       bool enabled;
-
-       if (!kstrtobool(str, &enabled))
-               vdso_enabled = enabled;
-       return 1;
-}
-__setup("vdso=", vdso_setup);
-
-/*
- * The vdso data page
- */
-static union {
-       struct vdso_data        data[CS_BASES];
-       u8                      page[PAGE_SIZE];
-} vdso_data_store __page_aligned_data;
-struct vdso_data *vdso_data = vdso_data_store.data;
-
 int vdso_getcpu_init(void)
 {
        set_tod_programmable_field(smp_processor_id());
@@ -92,10 +72,6 @@ int vdso_getcpu_init(void)
 }
 early_initcall(vdso_getcpu_init); /* Must be called before SMP init */
 
-/*
- * This is called from binfmt_elf, we create the special vma for the
- * vDSO and insert it into the mm struct tree
- */
 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 {
        struct mm_struct *mm = current->mm;
@@ -103,25 +79,14 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
        unsigned long vdso_base;
        int rc;
 
-       if (!vdso_enabled)
-               return 0;
-
-       if (is_compat_task())
+       if (!vdso_enabled || is_compat_task())
                return 0;
-
-       /*
-        * pick a base address for the vDSO in process space. We try to put
-        * it at vdso_base which is the "natural" base for it, but we might
-        * fail and end up putting it elsewhere.
-        */
        if (mmap_write_lock_killable(mm))
                return -EINTR;
        vdso_base = get_unmapped_area(NULL, 0, vdso_pages << PAGE_SHIFT, 0, 0);
-       if (IS_ERR_VALUE(vdso_base)) {
-               rc = vdso_base;
-               goto out_up;
-       }
-
+       rc = vdso_base;
+       if (IS_ERR_VALUE(vdso_base))
+               goto out;
        /*
         * our vma flags don't have VM_WRITE so by default, the process
         * isn't allowed to write those pages.
@@ -136,15 +101,12 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
                                       VM_READ|VM_EXEC|
                                       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
                                       &vdso_mapping);
-       if (IS_ERR(vma)) {
-               rc = PTR_ERR(vma);
-               goto out_up;
-       }
-
+       rc = PTR_ERR(vma);
+       if (IS_ERR(vma))
+               goto out;
        current->mm->context.vdso_base = vdso_base;
        rc = 0;
-
-out_up:
+out:
        mmap_write_unlock(mm);
        return rc;
 }
@@ -153,9 +115,7 @@ static int __init vdso_init(void)
 {
        int i;
 
-       /* Calculate the size of the vDSO */
        vdso_pages = ((vdso64_end - vdso64_start) >> PAGE_SHIFT) + 1;
-
        /* Make sure pages are in the correct state */
        vdso_pagelist = kcalloc(vdso_pages + 1, sizeof(struct page *),
                                GFP_KERNEL);
@@ -170,9 +130,7 @@ static int __init vdso_init(void)
        }
        vdso_pagelist[vdso_pages - 1] = virt_to_page(vdso_data);
        vdso_pagelist[vdso_pages] = NULL;
-
        get_page(virt_to_page(vdso_data));
-
        return 0;
 }
 arch_initcall(vdso_init);