s390/vdso: move data page before code pages

For consistency with x86 and arm64 move the data page before code
pages. Similar to commit 601255ae3c98 ("arm64: vdso: move data page
before code pages").

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
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 968b263..31920b7 100644 (file)
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -74,7 +74,8 @@ early_initcall(vdso_getcpu_init); /* Must be called before SMP init */
 
 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 {
-       unsigned long addr, vdso_text_start, vdso_text_len, vdso_mapping_len;
+       unsigned long vdso_text_len, vdso_mapping_len;
+       unsigned long vvar_start, vdso_text_start;
        struct mm_struct *mm = current->mm;
        struct vm_area_struct *vma;
        int rc;
@@ -85,25 +86,24 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
                return -EINTR;
        vdso_text_len = vdso_pages << PAGE_SHIFT;
        vdso_mapping_len = vdso_text_len + PAGE_SIZE;
-       addr = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
-       rc = addr;
-       if (IS_ERR_VALUE(addr))
+       vvar_start = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
+       rc = vvar_start;
+       if (IS_ERR_VALUE(vvar_start))
                goto out;
+       vma = _install_special_mapping(mm, vvar_start, PAGE_SIZE,
+                                      VM_READ|VM_MAYREAD|VM_PFNMAP,
+                                      &vvar_mapping);
+       rc = PTR_ERR(vma);
+       if (IS_ERR(vma))
+               goto out;
+       vdso_text_start = vvar_start + PAGE_SIZE;
        /* VM_MAYWRITE for COW so gdb can set breakpoints */
-       vdso_text_start = addr;
-       vma = _install_special_mapping(mm, addr, vdso_text_len,
+       vma = _install_special_mapping(mm, vdso_text_start, vdso_text_len,
                                       VM_READ|VM_EXEC|
                                       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
                                       &vdso_mapping);
-       rc = PTR_ERR(vma);
-       if (IS_ERR(vma))
-               goto out;
-       addr += vdso_text_len;
-       vma = _install_special_mapping(mm, addr, PAGE_SIZE,
-                                      VM_READ|VM_MAYREAD|VM_PFNMAP,
-                                      &vvar_mapping);
        if (IS_ERR(vma)) {
-               do_munmap(mm, vdso_text_start, vdso_text_len, NULL);
+               do_munmap(mm, vvar_start, PAGE_SIZE, NULL);
                rc = PTR_ERR(vma);
        } else {
                current->mm->context.vdso_base = vdso_text_start;

diff --git a/arch/s390/kernel/vdso64/vdso64.lds.S b/arch/s390/kernel/vdso64/vdso64.lds.S
index 7bde390..99063b4 100644 (file)
--- a/arch/s390/kernel/vdso64/vdso64.lds.S
+++ b/arch/s390/kernel/vdso64/vdso64.lds.S
@@ -13,6 +13,7 @@ ENTRY(_start)
 
 SECTIONS
 {
+       PROVIDE(_vdso_data = . - PAGE_SIZE);
        . = VDSO64_LBASE + SIZEOF_HEADERS;
 
        .hash           : { *(.hash) }                  :text
@@ -94,9 +95,6 @@ SECTIONS
        .debug_ranges   0 : { *(.debug_ranges) }
        .gnu.attributes 0 : { KEEP (*(.gnu.attributes)) }
 
-       . = ALIGN(PAGE_SIZE);
-       PROVIDE(_vdso_data = .);
-
        /DISCARD/       : {
                *(.note.GNU-stack)
                *(.branch_lt)