4 files changed, 47 insertions, 22 deletions

diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 253b72eaade6..6ba89a1ab0e5 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -55,7 +55,7 @@ VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
 $(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
 	$(call if_changed,vdso)
 
-HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/x86/include/uapi
+HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
 hostprogs-y			+= vdso2c
 
 quiet_cmd_vdso2c = VDSO2C  $@
@@ -134,7 +134,7 @@ VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
 override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
 
 targets += vdso32/vdso32.lds
-targets += vdso32/note.o vdso32/vclock_gettime.o vdso32/system_call.o
+targets += vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
 targets += vdso32/vclock_gettime.o
 
 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO
@@ -156,7 +156,8 @@ $(obj)/vdso32.so.dbg: FORCE \
 		      $(obj)/vdso32/vdso32.lds \
 		      $(obj)/vdso32/vclock_gettime.o \
 		      $(obj)/vdso32/note.o \
-		      $(obj)/vdso32/system_call.o
+		      $(obj)/vdso32/system_call.o \
+		      $(obj)/vdso32/sigreturn.o
 	$(call if_changed,vdso)
 
 #
diff --git a/arch/x86/entry/vdso/vdso32/sigreturn.S b/arch/x86/entry/vdso/vdso32/sigreturn.S
index d7ec4e251c0a..20633e026e82 100644
--- a/arch/x86/entry/vdso/vdso32/sigreturn.S
+++ b/arch/x86/entry/vdso/vdso32/sigreturn.S
@@ -1,11 +1,3 @@
-/*
- * Common code for the sigreturn entry points in vDSO images.
- * So far this code is the same for both int80 and sysenter versions.
- * This file is #include'd by int80.S et al to define them first thing.
- * The kernel assumes that the addresses of these routines are constant
- * for all vDSO implementations.
- */
-
 #include <linux/linkage.h>
 #include <asm/unistd_32.h>
 #include <asm/asm-offsets.h>
diff --git a/arch/x86/entry/vdso/vdso32/system_call.S b/arch/x86/entry/vdso/vdso32/system_call.S
index 0109ac6cb79c..ed4bc9731cbb 100644
--- a/arch/x86/entry/vdso/vdso32/system_call.S
+++ b/arch/x86/entry/vdso/vdso32/system_call.S
@@ -2,16 +2,11 @@
  * AT_SYSINFO entry point
 */
 
+#include <linux/linkage.h>
 #include <asm/dwarf2.h>
 #include <asm/cpufeatures.h>
 #include <asm/alternative-asm.h>
 
-/*
- * First get the common code for the sigreturn entry points.
- * This must come first.
- */
-#include "sigreturn.S"
-
 	.text
 	.globl __kernel_vsyscall
 	.type __kernel_vsyscall,@function
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index ab220ac9b3b9..3329844e3c43 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -12,6 +12,7 @@
 #include <linux/random.h>
 #include <linux/elf.h>
 #include <linux/cpu.h>
+#include <linux/ptrace.h>
 #include <asm/pvclock.h>
 #include <asm/vgtod.h>
 #include <asm/proto.h>
@@ -97,10 +98,40 @@ static int vdso_fault(const struct vm_special_mapping *sm,
 	return 0;
 }
 
-static const struct vm_special_mapping text_mapping = {
-	.name = "[vdso]",
-	.fault = vdso_fault,
-};
+static void vdso_fix_landing(const struct vdso_image *image,
+		struct vm_area_struct *new_vma)
+{
+#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
+	if (in_ia32_syscall() && image == &vdso_image_32) {
+		struct pt_regs *regs = current_pt_regs();
+		unsigned long vdso_land = image->sym_int80_landing_pad;
+		unsigned long old_land_addr = vdso_land +
+			(unsigned long)current->mm->context.vdso;
+
+		/* Fixing userspace landing - look at do_fast_syscall_32 */
+		if (regs->ip == old_land_addr)
+			regs->ip = new_vma->vm_start + vdso_land;
+	}
+#endif
+}
+
+static int vdso_mremap(const struct vm_special_mapping *sm,
+		struct vm_area_struct *new_vma)
+{
+	unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
+	const struct vdso_image *image = current->mm->context.vdso_image;
+
+	if (image->size != new_size)
+		return -EINVAL;
+
+	if (WARN_ON_ONCE(current->mm != new_vma->vm_mm))
+		return -EFAULT;
+
+	vdso_fix_landing(image, new_vma);
+	current->mm->context.vdso = (void __user *)new_vma->vm_start;
+
+	return 0;
+}
 
 static int vvar_fault(const struct vm_special_mapping *sm,
 		      struct vm_area_struct *vma, struct vm_fault *vmf)
@@ -151,6 +182,12 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
 	struct vm_area_struct *vma;
 	unsigned long addr, text_start;
 	int ret = 0;
+
+	static const struct vm_special_mapping vdso_mapping = {
+		.name = "[vdso]",
+		.fault = vdso_fault,
+		.mremap = vdso_mremap,
+	};
 	static const struct vm_special_mapping vvar_mapping = {
 		.name = "[vvar]",
 		.fault = vvar_fault,
@@ -185,7 +222,7 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
 				       image->size,
 				       VM_READ|VM_EXEC|
 				       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
-				       &text_mapping);
+				       &vdso_mapping);
 
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);