Commit-ID: 576ebfefd37bd41e965787f60684c8e4b7f79457 Gitweb: http://git.kernel.org/tip/576ebfefd37bd41e965787f60684c8e4b7f79457 Author: Dmitry Safonov <dsafo...@virtuozzo.com> AuthorDate: Mon, 5 Sep 2016 16:33:04 +0300 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Wed, 14 Sep 2016 21:28:09 +0200
x86/vdso: Replace calculate_addr in map_vdso() with addr That will allow to specify address where to map vDSO blob. For the randomized vDSO mappings introduce map_vdso_randomized() which will simplify calls to map_vdso. Signed-off-by: Dmitry Safonov <dsafo...@virtuozzo.com> Acked-by: Andy Lutomirski <l...@kernel.org> Cc: 0x7f454...@gmail.com Cc: o...@redhat.com Cc: linux...@kvack.org Cc: gorcu...@openvz.org Cc: xe...@virtuozzo.com Link: http://lkml.kernel.org/r/20160905133308.28234-3-dsafo...@virtuozzo.com Signed-off-by: Thomas Gleixner <t...@linutronix.de> --- arch/x86/entry/vdso/vma.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 3bab6ba..5bcb25a 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -176,11 +176,16 @@ static int vvar_fault(const struct vm_special_mapping *sm, return VM_FAULT_SIGBUS; } -static int map_vdso(const struct vdso_image *image, bool calculate_addr) +/* + * Add vdso and vvar mappings to current process. + * @image - blob to map + * @addr - request a specific address (zero to map at free addr) + */ +static int map_vdso(const struct vdso_image *image, unsigned long addr) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma; - unsigned long addr, text_start; + unsigned long text_start; int ret = 0; static const struct vm_special_mapping vdso_mapping = { @@ -193,13 +198,6 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr) .fault = vvar_fault, }; - if (calculate_addr) { - addr = vdso_addr(current->mm->start_stack, - image->size - image->sym_vvar_start); - } else { - addr = 0; - } - if (down_write_killable(&mm->mmap_sem)) return -EINTR; @@ -251,13 +249,20 @@ up_fail: return ret; } +static int map_vdso_randomized(const struct vdso_image *image) +{ + unsigned long addr = vdso_addr(current->mm->start_stack, + image->size - image->sym_vvar_start); + return map_vdso(image, addr); +} + #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION) static int load_vdso32(void) { if (vdso32_enabled != 1) /* Other values all mean "disabled" */ return 0; - return map_vdso(&vdso_image_32, false); + return map_vdso(&vdso_image_32, 0); } #endif @@ -267,7 +272,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) if (!vdso64_enabled) return 0; - return map_vdso(&vdso_image_64, true); + return map_vdso_randomized(&vdso_image_64); } #ifdef CONFIG_COMPAT @@ -278,8 +283,7 @@ int compat_arch_setup_additional_pages(struct linux_binprm *bprm, if (test_thread_flag(TIF_X32)) { if (!vdso64_enabled) return 0; - - return map_vdso(&vdso_image_x32, true); + return map_vdso_randomized(&vdso_image_x32); } #endif #ifdef CONFIG_IA32_EMULATION
