Those pointers were initialized before call to _install_special_mapping
after the commit f7b6eb3fa072 ("x86: Set context.vdso before installing
the mapping"). This is not required anymore as special mappings have
their vma name and don't use arch_vma_name() after commit a62c34bd2a8a
("x86, mm: Improve _install_special_mapping and fix x86 vdso naming").
So, this way to init looks less entangled.
I even belive, we can remove null initializers:
- on failure load_elf_binary() will not start a new thread;
- arch_prctl will have the same pointers as before syscall.Cc: [email protected] Cc: Cyrill Gorcunov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: [email protected] Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Dmitry Safonov <[email protected]> --- arch/x86/entry/vdso/vma.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 23c881caabd1..e739002427ed 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -161,8 +161,6 @@ static int map_vdso(const struct vdso_image *image, unsigned long addr) } text_start = addr - image->sym_vvar_start; - current->mm->context.vdso = (void __user *)text_start; - current->mm->context.vdso_image = image; /* * MAYWRITE to allow gdb to COW and set breakpoints @@ -189,14 +187,12 @@ static int map_vdso(const struct vdso_image *image, unsigned long addr) if (IS_ERR(vma)) { ret = PTR_ERR(vma); do_munmap(mm, text_start, image->size); + } else { + current->mm->context.vdso = (void __user *)text_start; + current->mm->context.vdso_image = image; } up_fail: - if (ret) { - current->mm->context.vdso = NULL; - current->mm->context.vdso_image = NULL; - } - up_write(&mm->mmap_sem); return ret; } -- 2.10.1
