x86, vdso: Move the 32-bit vdso special pages after the text

This unifies the vdso mapping code and teaches it how to map special
pages at addresses corresponding to symbols in the vdso image.  The
new code is used for all vdso variants, but so far only the 32-bit
variants use the new vvar page position.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/b6d7858ad7b5ac3fd3c29cab6d6d769bc45d195e.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 3 insertions, 112 deletions

diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index d41460118a28..c3ed708e50f4 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -8,28 +8,12 @@
 
 #include <linux/init.h>
 #include <linux/smp.h>
-#include <linux/thread_info.h>
-#include <linux/sched.h>
-#include <linux/gfp.h>
-#include <linux/string.h>
-#include <linux/elf.h>
-#include <linux/mm.h>
-#include <linux/err.h>
-#include <linux/module.h>
-#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/mm_types.h>
 
 #include <asm/cpufeature.h>
-#include <asm/msr.h>
-#include <asm/pgtable.h>
-#include <asm/unistd.h>
-#include <asm/elf.h>
-#include <asm/tlbflush.h>
+#include <asm/processor.h>
 #include <asm/vdso.h>
-#include <asm/proto.h>
-#include <asm/fixmap.h>
-#include <asm/hpet.h>
-#include <asm/vvar.h>
-#include <asm/vdso32.h>
 
 #ifdef CONFIG_COMPAT_VDSO
 #define VDSO_DEFAULT	0
@@ -37,10 +21,6 @@
 #define VDSO_DEFAULT	1
 #endif
 
-#ifdef CONFIG_X86_64
-#define arch_setup_additional_pages	syscall32_setup_pages
-#endif
-
 /*
  * Should the kernel map a VDSO page into processes and pass its
  * address down to glibc upon exec()?
@@ -101,95 +81,6 @@ int __init sysenter_setup(void)
 	return 0;
 }
 
-/* Setup a VMA at program startup for the vsyscall page */
-int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
-{
-	struct mm_struct *mm = current->mm;
-	unsigned long addr;
-	int ret = 0;
-	struct vm_area_struct *vma;
-	unsigned long vdso32_size = selected_vdso32->size;
-
-#ifdef CONFIG_X86_X32_ABI
-	if (test_thread_flag(TIF_X32))
-		return x32_setup_additional_pages(bprm, uses_interp);
-#endif
-
-	if (vdso32_enabled != 1)  /* Other values all mean "disabled" */
-		return 0;
-
-	down_write(&mm->mmap_sem);
-
-	addr = get_unmapped_area(NULL, 0, vdso32_size + VDSO_OFFSET(VDSO_PREV_PAGES), 0, 0);
-	if (IS_ERR_VALUE(addr)) {
-		ret = addr;
-		goto up_fail;
-	}
-
-	addr += VDSO_OFFSET(VDSO_PREV_PAGES);
-
-	current->mm->context.vdso = (void __user *)addr;
-
-	/*
-	 * MAYWRITE to allow gdb to COW and set breakpoints
-	 */
-	ret = install_special_mapping(mm,
-			addr,
-			vdso32_size,
-			VM_READ|VM_EXEC|
-			VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
-			selected_vdso32->pages);
-
-	if (ret)
-		goto up_fail;
-
-	vma = _install_special_mapping(mm,
-			addr -  VDSO_OFFSET(VDSO_PREV_PAGES),
-			VDSO_OFFSET(VDSO_PREV_PAGES),
-			VM_READ,
-			NULL);
-
-	if (IS_ERR(vma)) {
-		ret = PTR_ERR(vma);
-		goto up_fail;
-	}
-
-	ret = remap_pfn_range(vma,
-		addr - VDSO_OFFSET(VDSO_VVAR_PAGE),
-		__pa_symbol(&__vvar_page) >> PAGE_SHIFT,
-		PAGE_SIZE,
-		PAGE_READONLY);
-
-	if (ret)
-		goto up_fail;
-
-#ifdef CONFIG_HPET_TIMER
-	if (hpet_address) {
-		ret = io_remap_pfn_range(vma,
-			addr - VDSO_OFFSET(VDSO_HPET_PAGE),
-			hpet_address >> PAGE_SHIFT,
-			PAGE_SIZE,
-			pgprot_noncached(PAGE_READONLY));
-
-		if (ret)
-			goto up_fail;
-	}
-#endif
-
-	if (selected_vdso32->sym_VDSO32_SYSENTER_RETURN)
-		current_thread_info()->sysenter_return =
-			current->mm->context.vdso +
-			selected_vdso32->sym_VDSO32_SYSENTER_RETURN;
-
-  up_fail:
-	if (ret)
-		current->mm->context.vdso = NULL;
-
-	up_write(&mm->mmap_sem);
-
-	return ret;
-}
-
 #ifdef CONFIG_X86_64
 
 subsys_initcall(sysenter_setup);