This is a note to let you know that I've just added the patch titled s390/vdso: always enable vdso to the 5.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: s390-vdso-always-enable-vdso.patch and it can be found in the queue-5.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From d57778feb9878aa6b79c615fd029c2112d40a747 Mon Sep 17 00:00:00 2001 From: Sven Schnelle <svens@xxxxxxxxxxxxx> Date: Wed, 23 Jun 2021 14:10:00 +0200 Subject: s390/vdso: always enable vdso From: Sven Schnelle <svens@xxxxxxxxxxxxx> commit d57778feb9878aa6b79c615fd029c2112d40a747 upstream. With the upcoming move of the svc sigreturn instruction from the signal frame to vdso we need to have vdso always enabled. Signed-off-by: Sven Schnelle <svens@xxxxxxxxxxxxx> Reviewed-by: Heiko Carstens <hca@xxxxxxxxxxxxx> Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/s390/include/asm/elf.h | 11 ++++------- arch/s390/kernel/vdso.c | 21 ++++----------------- 2 files changed, 8 insertions(+), 24 deletions(-) --- a/arch/s390/include/asm/elf.h +++ b/arch/s390/include/asm/elf.h @@ -146,8 +146,6 @@ typedef s390_compat_regs compat_elf_greg #include <asm/vdso.h> -extern unsigned int vdso_enabled; - /* * This is used to ensure we don't load something for the wrong architecture. */ @@ -268,11 +266,10 @@ do { \ #define STACK_RND_MASK MMAP_RND_MASK /* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */ -#define ARCH_DLINFO \ -do { \ - if (vdso_enabled) \ - NEW_AUX_ENT(AT_SYSINFO_EHDR, \ - (unsigned long)current->mm->context.vdso_base); \ +#define ARCH_DLINFO \ +do { \ + NEW_AUX_ENT(AT_SYSINFO_EHDR, \ + (unsigned long)current->mm->context.vdso_base); \ } while (0) struct linux_binprm; --- a/arch/s390/kernel/vdso.c +++ b/arch/s390/kernel/vdso.c @@ -37,18 +37,6 @@ enum vvar_pages { VVAR_NR_PAGES, }; -unsigned int __read_mostly vdso_enabled = 1; - -static int __init vdso_setup(char *str) -{ - bool enabled; - - if (!kstrtobool(str, &enabled)) - vdso_enabled = enabled; - return 1; -} -__setup("vdso=", vdso_setup); - #ifdef CONFIG_TIME_NS struct vdso_data *arch_get_vdso_data(void *vvar_page) { @@ -176,7 +164,7 @@ int arch_setup_additional_pages(struct l int rc; BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES); - if (!vdso_enabled || is_compat_task()) + if (is_compat_task()) return 0; if (mmap_write_lock_killable(mm)) return -EINTR; @@ -218,10 +206,9 @@ static int __init vdso_init(void) vdso_pages = (vdso64_end - vdso64_start) >> PAGE_SHIFT; pages = kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL); - if (!pages) { - vdso_enabled = 0; - return -ENOMEM; - } + if (!pages) + panic("failed to allocate VDSO pages"); + for (i = 0; i < vdso_pages; i++) pages[i] = virt_to_page(vdso64_start + i * PAGE_SIZE); pages[vdso_pages] = NULL; Patches currently in stable-queue which might be from svens@xxxxxxxxxxxxx are queue-5.12/s390-vdso-rename-vdso64_lbase-to-vdso_lbase.patch queue-5.12/s390-vdso64-add-sigreturn-rt_sigreturn-and-restart_syscall.patch queue-5.12/s390-signal-switch-to-using-vdso-for-sigreturn-and-syscall-restart.patch queue-5.12/s390-vdso-add-minimal-compat-vdso.patch queue-5.12/s390-vdso-always-enable-vdso.patch