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Diffstat (limited to 'arch/x86/entry/vdso/vma.c')
-rw-r--r--arch/x86/entry/vdso/vma.c67
1 files changed, 46 insertions, 21 deletions
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index ab220ac9b..f84076665 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);
@@ -294,15 +331,9 @@ static void vgetcpu_cpu_init(void *arg)
write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S);
}
-static int
-vgetcpu_cpu_notifier(struct notifier_block *n, unsigned long action, void *arg)
+static int vgetcpu_online(unsigned int cpu)
{
- long cpu = (long)arg;
-
- if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN)
- smp_call_function_single(cpu, vgetcpu_cpu_init, NULL, 1);
-
- return NOTIFY_DONE;
+ return smp_call_function_single(cpu, vgetcpu_cpu_init, NULL, 1);
}
static int __init init_vdso(void)
@@ -313,15 +344,9 @@ static int __init init_vdso(void)
init_vdso_image(&vdso_image_x32);
#endif
- cpu_notifier_register_begin();
-
- on_each_cpu(vgetcpu_cpu_init, NULL, 1);
/* notifier priority > KVM */
- __hotcpu_notifier(vgetcpu_cpu_notifier, 30);
-
- cpu_notifier_register_done();
-
- return 0;
+ return cpuhp_setup_state(CPUHP_AP_X86_VDSO_VMA_ONLINE,
+ "AP_X86_VDSO_VMA_ONLINE", vgetcpu_online, NULL);
}
subsys_initcall(init_vdso);
#endif /* CONFIG_X86_64 */