Re: [PATCH v2 06/19] elf/vdso: Reuse arch_setup_additional_pages() parameters

Christophe Leroy
2020-11-24T06:22:06Z

"Reuse arch_setup_additional_pages() parameters"

Did you mean "remove" ? Or "Revise" ?

Maybe could be:

"Modify arch_setup_additional_pages() parameters"

Le 24/11/2020 à 01:29, Dmitry Safonov a écrit :
> Both parameters of arch_setup_additional_pages() are currently unused.
> commit fc5243d98ac2 ("[S390] arch_setup_additional_pages arguments")
> tried to introduce useful arguments, but they still are not used.
>
> Remove old parameters and introduce sysinfo_ehdr argument that will be
> used to return vdso address to put as AT_SYSINFO_EHDR tag in auxiliary
> vector. The reason to add this parameter is that many architecture
> have vDSO pointer saved in their mm->context with the only purpose
> to use it later in ARCH_DLINFO. That's the macro for elf loader
> to setup sysinfo_ehdr tag.
>
> Return sysinfo_ehdr address that will be later used by ARCH_DLINFO as
> an argument. That will allow to drop vDSO pointer from mm->context
> and any code responsible to track vDSO position on platforms that
> don't use vDSO as a landing in userspace (arm/s390/sparc).
>
> Cc: Albert Ou <aou@eecs.berkeley.edu>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Palmer Dabbelt <palmer@dabbelt.com>
> Cc: Paul Walmsley <paul.walmsley@sifive.com>
> Cc: linux-fsdevel@vger.kernel.org
> Signed-off-by: Dmitry Safonov <dima@arista.com>
> ---
> arch/arm/include/asm/vdso.h | 6 ++++--
> arch/arm/kernel/process.c | 4 ++--
> arch/arm/kernel/vdso.c | 10 +++++++---
> arch/arm64/kernel/vdso.c | 17 ++++++++--------
> arch/csky/kernel/vdso.c | 3 ++-
> arch/hexagon/kernel/vdso.c | 3 ++-
> arch/mips/kernel/vdso.c | 3 ++-
> arch/nds32/kernel/vdso.c | 3 ++-
> arch/nios2/mm/init.c | 2 +-
> arch/powerpc/kernel/vdso.c | 3 ++-
> arch/riscv/kernel/vdso.c | 11 +++++-----
> arch/s390/kernel/vdso.c | 3 ++-
> arch/sh/kernel/vsyscall/vsyscall.c | 3 ++-
> arch/sparc/vdso/vma.c | 15 +++++++-------
> arch/x86/entry/vdso/vma.c | 32 +++++++++++++++++-------------
> arch/x86/um/vdso/vma.c | 2 +-
> fs/binfmt_elf.c | 3 ++-
> fs/binfmt_elf_fdpic.c | 3 ++-
> include/linux/elf.h | 17 +++++++++++-----
> 19 files changed, 85 insertions(+), 58 deletions(-)
>
> diff --git a/arch/arm/include/asm/vdso.h b/arch/arm/include/asm/vdso.h
> index 5b85889f82ee..6b2b3b1fe833 100644
> --- a/arch/arm/include/asm/vdso.h
> +++ b/arch/arm/include/asm/vdso.h
> @@ -10,13 +10,15 @@ struct mm_struct;
>
> #ifdef CONFIG_VDSO
>
> -void arm_install_vdso(struct mm_struct *mm, unsigned long addr);
> +void arm_install_vdso(struct mm_struct *mm, unsigned long addr,
> + unsigned long *sysinfo_ehdr);
>
> extern unsigned int vdso_total_pages;
>
> #else /* CONFIG_VDSO */
>
> -static inline void arm_install_vdso(struct mm_struct *mm, unsigned long addr)
> +static inline void arm_install_vdso(struct mm_struct *mm, unsigned long addr,
> + unsigned long *sysinfo_ehdr)
> {
> }
>
> diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
> index d0220da1d1b1..0e90cba8ac7a 100644
> --- a/arch/arm/kernel/process.c
> +++ b/arch/arm/kernel/process.c
> @@ -389,7 +389,7 @@ static const struct vm_special_mapping sigpage_mapping = {
> .mremap = sigpage_mremap,
> };
>
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> @@ -430,7 +430,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> * to be fatal to the process, so no error check needed
> * here.
> */
> - arm_install_vdso(mm, addr + PAGE_SIZE);
> + arm_install_vdso(mm, addr + PAGE_SIZE, sysinfo_ehdr);
>
> up_fail:
> mmap_write_unlock(mm);
> diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
> index 3408269d19c7..710e5ca99a53 100644
> --- a/arch/arm/kernel/vdso.c
> +++ b/arch/arm/kernel/vdso.c
> @@ -233,7 +233,8 @@ static int install_vvar(struct mm_struct *mm, unsigned long addr)
> }
>
> /* assumes mmap_lock is write-locked */
> -void arm_install_vdso(struct mm_struct *mm, unsigned long addr)
> +void arm_install_vdso(struct mm_struct *mm, unsigned long addr,
> + unsigned long *sysinfo_ehdr)
> {
> struct vm_area_struct *vma;
> unsigned long len;
> @@ -254,7 +255,10 @@ void arm_install_vdso(struct mm_struct *mm, unsigned long addr)
> VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
> &vdso_text_mapping);
>
> - if (!IS_ERR(vma))
> - mm->context.vdso = addr;
> + if (IS_ERR(vma))
> + return;
> +
> + mm->context.vdso = addr;
> + *sysinfo_ehdr = addr;
> }
>
> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
> index 1b710deb84d6..666338724a07 100644
> --- a/arch/arm64/kernel/vdso.c
> +++ b/arch/arm64/kernel/vdso.c
> @@ -213,8 +213,7 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
>
> static int __setup_additional_pages(enum vdso_abi abi,
> struct mm_struct *mm,
> - struct linux_binprm *bprm,
> - int uses_interp)
> + unsigned long *sysinfo_ehdr)
> {
> unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
> unsigned long gp_flags = 0;
> @@ -250,6 +249,8 @@ static int __setup_additional_pages(enum vdso_abi abi,
> if (IS_ERR(ret))
> goto up_fail;
>
> + *sysinfo_ehdr = vdso_base;
> +
> return 0;
>
> up_fail:
> @@ -401,8 +402,7 @@ static int aarch32_sigreturn_setup(struct mm_struct *mm)
> return PTR_ERR_OR_ZERO(ret);
> }
>
> -static int aarch32_setup_additional_pages(struct linux_binprm *bprm,
> - int uses_interp)
> +static int aarch32_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> struct mm_struct *mm = current->mm;
> int ret;
> @@ -412,8 +412,7 @@ static int aarch32_setup_additional_pages(struct linux_binprm *bprm,
> return ret;
>
> if (IS_ENABLED(CONFIG_COMPAT_VDSO)) {
> - ret = __setup_additional_pages(VDSO_ABI_AA32, mm, bprm,
> - uses_interp);
> + ret = __setup_additional_pages(VDSO_ABI_AA32, mm, sysinfo_ehdr);
> if (ret)
> return ret;
> }
> @@ -447,7 +446,7 @@ static int __init vdso_init(void)
> }
> arch_initcall(vdso_init);
>
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> struct mm_struct *mm = current->mm;
> int ret;
> @@ -456,9 +455,9 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> return -EINTR;
>
> if (is_compat_task())
> - ret = aarch32_setup_additional_pages(bprm, uses_interp);
> + ret = aarch32_setup_additional_pages(sysinfo_ehdr);
> else
> - ret = __setup_additional_pages(VDSO_ABI_AA64, mm, bprm, uses_interp);
> + ret = __setup_additional_pages(VDSO_ABI_AA64, mm, sysinfo_ehdr);
>
> mmap_write_unlock(mm);
>
> diff --git a/arch/csky/kernel/vdso.c b/arch/csky/kernel/vdso.c
> index abc3dbc658d4..f72f76915c59 100644
> --- a/arch/csky/kernel/vdso.c
> +++ b/arch/csky/kernel/vdso.c
> @@ -44,7 +44,7 @@ static int __init init_vdso(void)
> }
> subsys_initcall(init_vdso);
>
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> int ret;
> unsigned long addr;
> @@ -68,6 +68,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> goto up_fail;
>
> mm->context.vdso = (void *)addr;
> + *sysinfo_ehdr = addr;
>
> up_fail:
> mmap_write_unlock(mm);
> diff --git a/arch/hexagon/kernel/vdso.c b/arch/hexagon/kernel/vdso.c
> index b70970ac809f..39e78fe82b99 100644
> --- a/arch/hexagon/kernel/vdso.c
> +++ b/arch/hexagon/kernel/vdso.c
> @@ -46,7 +46,7 @@ arch_initcall(vdso_init);
> /*
> * Called from binfmt_elf. Create a VMA for the vDSO page.
> */
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> int ret;
> unsigned long vdso_base;
> @@ -74,6 +74,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> goto up_fail;
>
> mm->context.vdso = (void *)vdso_base;
> + *sysinfo_ehdr = vdso_base;
>
> up_fail:
> mmap_write_unlock(mm);
> diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c
> index 7d0b91ad2581..e124c68322bb 100644
> --- a/arch/mips/kernel/vdso.c
> +++ b/arch/mips/kernel/vdso.c
> @@ -86,7 +86,7 @@ static unsigned long vdso_base(void)
> return base;
> }
>
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> struct mips_vdso_image *image = current->thread.abi->vdso;
> struct mm_struct *mm = current->mm;
> @@ -184,6 +184,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> }
>
> mm->context.vdso = (void *)vdso_addr;
> + *sysinfo_ehdr = vdso_addr;
> ret = 0;
>
> out:
> diff --git a/arch/nds32/kernel/vdso.c b/arch/nds32/kernel/vdso.c
> index e16009a07971..530164221166 100644
> --- a/arch/nds32/kernel/vdso.c
> +++ b/arch/nds32/kernel/vdso.c
> @@ -111,7 +111,7 @@ unsigned long inline vdso_random_addr(unsigned long vdso_mapping_len)
> return addr;
> }
>
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> struct mm_struct *mm = current->mm;
> unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
> @@ -176,6 +176,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> /*Map vdso to user space */
> vdso_base += PAGE_SIZE;
> mm->context.vdso = (void *)vdso_base;
> + *sysinfo_ehdr = vdso_base;
> vma = _install_special_mapping(mm, vdso_base, vdso_text_len,
> VM_READ | VM_EXEC |
> VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
> diff --git a/arch/nios2/mm/init.c b/arch/nios2/mm/init.c
> index 61862dbb0e32..e09e54198ac6 100644
> --- a/arch/nios2/mm/init.c
> +++ b/arch/nios2/mm/init.c
> @@ -104,7 +104,7 @@ static int alloc_kuser_page(void)
> }
> arch_initcall(alloc_kuser_page);
>
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> struct mm_struct *mm = current->mm;
> int ret;
> diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
> index 8dad44262e75..0ec3bbe7fb36 100644
> --- a/arch/powerpc/kernel/vdso.c
> +++ b/arch/powerpc/kernel/vdso.c
> @@ -122,7 +122,7 @@ struct lib64_elfinfo
> * This is called from binfmt_elf, we create the special vma for the
> * vDSO and insert it into the mm struct tree
> */
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> struct mm_struct *mm = current->mm;
> struct page **vdso_pagelist;
> @@ -211,6 +211,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> }
>
> mmap_write_unlock(mm);
> + *sysinfo_ehdr = vdso_base;
> return 0;
>
> fail_mmapsem:
> diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c
> index 678204231700..55b6d36d42ec 100644
> --- a/arch/riscv/kernel/vdso.c
> +++ b/arch/riscv/kernel/vdso.c
> @@ -56,11 +56,10 @@ static int __init vdso_init(void)
> }
> arch_initcall(vdso_init);
>
> -int arch_setup_additional_pages(struct linux_binprm *bprm,
> - int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> struct mm_struct *mm = current->mm;
> - unsigned long vdso_base, vdso_len;
> + unsigned long vdso_base, vvar_base, vdso_len;
> int ret;
>
> vdso_len = (vdso_pages + 1) << PAGE_SHIFT;
> @@ -89,12 +88,14 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
> goto end;
> }
>
> - vdso_base += (vdso_pages << PAGE_SHIFT);
> - ret = install_special_mapping(mm, vdso_base, PAGE_SIZE,
> + vvar_base = vdso_base + (vdso_pages << PAGE_SHIFT);
> + ret = install_special_mapping(mm, vvar_base, PAGE_SIZE,
> (VM_READ | VM_MAYREAD), &vdso_pagelist[vdso_pages]);
>
> if (unlikely(ret))
> mm->context.vdso = NULL;
> + else
> + *sysinfo_ehdr = vdso_base;
> end:
> mmap_write_unlock(mm);
> return ret;
> diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
> index 6c9ec9521203..810b72f8985c 100644
> --- a/arch/s390/kernel/vdso.c
> +++ b/arch/s390/kernel/vdso.c
> @@ -150,7 +150,7 @@ void vdso_free_per_cpu(struct lowcore *lowcore)
> * This is called from binfmt_elf, we create the special vma for the
> * vDSO and insert it into the mm struct tree
> */
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> @@ -205,6 +205,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> }
>
> current->mm->context.vdso_base = vdso_base;
> + *sysinfo_ehdr = vdso_base;
> rc = 0;
>
> out_up:
> diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c
> index 1bd85a6949c4..de8df3261b4f 100644
> --- a/arch/sh/kernel/vsyscall/vsyscall.c
> +++ b/arch/sh/kernel/vsyscall/vsyscall.c
> @@ -55,7 +55,7 @@ int __init vsyscall_init(void)
> }
>
> /* Setup a VMA at program startup for the vsyscall page */
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> struct mm_struct *mm = current->mm;
> unsigned long addr;
> @@ -78,6 +78,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> goto up_fail;
>
> current->mm->context.vdso = (void *)addr;
> + *sysinfo_ehdr = addr;
>
> up_fail:
> mmap_write_unlock(mm);
> diff --git a/arch/sparc/vdso/vma.c b/arch/sparc/vdso/vma.c
> index cc19e09b0fa1..bf9195fe9bcc 100644
> --- a/arch/sparc/vdso/vma.c
> +++ b/arch/sparc/vdso/vma.c
> @@ -346,8 +346,6 @@ static int __init init_vdso(void)
> }
> subsys_initcall(init_vdso);
>
> -struct linux_binprm;
> -
> /* Shuffle the vdso up a bit, randomly. */
> static unsigned long vdso_addr(unsigned long start, unsigned int len)
> {
> @@ -359,7 +357,8 @@ static unsigned long vdso_addr(unsigned long start, unsigned int len)
> }
>
> static int map_vdso(const struct vdso_image *image,
> - struct vm_special_mapping *vdso_mapping)
> + struct vm_special_mapping *vdso_mapping,
> + unsigned long *sysinfo_ehdr)
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> @@ -421,12 +420,14 @@ static int map_vdso(const struct vdso_image *image,
> up_fail:
> if (ret)
> current->mm->context.vdso = NULL;
> + else
> + *sysinfo_ehdr = text_start;
>
> mmap_write_unlock(mm);
> return ret;
> }
>
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
>
> if (!vdso_enabled)
> @@ -434,11 +435,11 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
>
> #if defined CONFIG_COMPAT
> if (!(is_32bit_task()))
> - return map_vdso(&vdso_image_64_builtin, &vdso_mapping64);
> + return map_vdso(&vdso_image_64_builtin, &vdso_mapping64, sysinfo_ehdr);
> else
> - return map_vdso(&vdso_image_32_builtin, &vdso_mapping32);
> + return map_vdso(&vdso_image_32_builtin, &vdso_mapping32, sysinfo_ehdr);
> #else
> - return map_vdso(&vdso_image_64_builtin, &vdso_mapping64);
> + return map_vdso(&vdso_image_64_builtin, &vdso_mapping64, sysinfo_ehdr);
> #endif
>
> }
> diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
> index aace862ed9a1..5b9020742e66 100644
> --- a/arch/x86/entry/vdso/vma.c
> +++ b/arch/x86/entry/vdso/vma.c
> @@ -243,7 +243,8 @@ static const struct vm_special_mapping vvar_mapping = {
> * @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)
> +static int map_vdso(const struct vdso_image *image, unsigned long addr,
> + unsigned long *sysinfo_ehdr)
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> @@ -290,6 +291,7 @@ static int map_vdso(const struct vdso_image *image, unsigned long addr)
> } else {
> current->mm->context.vdso = (void __user *)text_start;
> current->mm->context.vdso_image = image;
> + *sysinfo_ehdr = text_start;
> }
>
> up_fail:
> @@ -342,11 +344,12 @@ static unsigned long vdso_addr(unsigned long start, unsigned len)
> return addr;
> }
>
> -static int map_vdso_randomized(const struct vdso_image *image)
> +static int map_vdso_randomized(const struct vdso_image *image,
> + unsigned long *sysinfo_ehdr)
> {
> unsigned long addr = vdso_addr(current->mm->start_stack, image->size-image->sym_vvar_start);
>
> - return map_vdso(image, addr);
> + return map_vdso(image, addr, sysinfo_ehdr);
> }
> #endif
>
> @@ -354,6 +357,7 @@ int map_vdso_once(const struct vdso_image *image, unsigned long addr)
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> + unsigned long unused;
>
> mmap_write_lock(mm);
> /*
> @@ -372,19 +376,19 @@ int map_vdso_once(const struct vdso_image *image, unsigned long addr)
> }
> mmap_write_unlock(mm);
>
> - return map_vdso(image, addr);
> + return map_vdso(image, addr, &unused);
> }
>
> #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
> -static int load_vdso_ia32(void)
> +static int load_vdso_ia32(unsigned long *sysinfo_ehdr)
> {
> if (vdso32_enabled != 1) /* Other values all mean "disabled" */
> return 0;
>
> - return map_vdso(&vdso_image_32, 0);
> + return map_vdso(&vdso_image_32, 0, sysinfo_ehdr);
> }
> #else
> -static int load_vdso_ia32(void)
> +static int load_vdso_ia32(unsigned long *sysinfo_ehdr)
> {
> WARN_ON_ONCE(1);
> return -ENODATA;
> @@ -392,32 +396,32 @@ static int load_vdso_ia32(void)
> #endif
>
> #ifdef CONFIG_X86_64
> -static int load_vdso_64(void)
> +static int load_vdso_64(unsigned long *sysinfo_ehdr)
> {
> if (!vdso64_enabled)
> return 0;
>
> #ifdef CONFIG_X86_X32_ABI
> if (in_x32_syscall())
> - return map_vdso_randomized(&vdso_image_x32);
> + return map_vdso_randomized(&vdso_image_x32, sysinfo_ehdr);
> #endif
>
> - return map_vdso_randomized(&vdso_image_64);
> + return map_vdso_randomized(&vdso_image_64, sysinfo_ehdr);
> }
> #else
> -static int load_vdso_64(void)
> +static int load_vdso_64(unsigned long *sysinfo_ehdr)
> {
> WARN_ON_ONCE(1);
> return -ENODATA;
> }
> #endif
>
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> if (in_ia32_syscall())
> - return load_vdso_ia32();
> + return load_vdso_ia32(sysinfo_ehdr);
>
> - return load_vdso_64();
> + return load_vdso_64(sysinfo_ehdr);
> }
>
> #ifdef CONFIG_X86_64
> diff --git a/arch/x86/um/vdso/vma.c b/arch/x86/um/vdso/vma.c
> index 76d9f6ce7a3d..77488065f7cc 100644
> --- a/arch/x86/um/vdso/vma.c
> +++ b/arch/x86/um/vdso/vma.c
> @@ -50,7 +50,7 @@ static int __init init_vdso(void)
> }
> subsys_initcall(init_vdso);
>
> -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> +int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> int err;
> struct mm_struct *mm = current->mm;
> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
> index b9adbeb59101..049ff514aa19 100644
> --- a/fs/binfmt_elf.c
> +++ b/fs/binfmt_elf.c
> @@ -833,6 +833,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
> unsigned long interp_load_addr = 0;
> unsigned long start_code, end_code, start_data, end_data;
> unsigned long reloc_func_desc __maybe_unused = 0;
> + unsigned long sysinfo_ehdr = 0;
> int executable_stack = EXSTACK_DEFAULT;
> struct elfhdr *elf_ex = (struct elfhdr *)bprm->buf;
> struct elfhdr *interp_elf_ex = NULL;
> @@ -1249,7 +1250,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
>
> set_binfmt(&elf_format);
>
> - retval = arch_setup_additional_pages(bprm, !!interpreter);
> + retval = arch_setup_additional_pages(&sysinfo_ehdr);
> if (retval < 0)
> goto out;
>
> diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
> index b9a6d1b2b5bb..c9ee3c240855 100644
> --- a/fs/binfmt_elf_fdpic.c
> +++ b/fs/binfmt_elf_fdpic.c
> @@ -183,6 +183,7 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
> {
> struct elf_fdpic_params exec_params, interp_params;
> struct pt_regs *regs = current_pt_regs();
> + unsigned long sysinfo_ehdr = 0;
> struct elf_phdr *phdr;
> unsigned long stack_size, entryaddr;
> #ifdef ELF_FDPIC_PLAT_INIT
> @@ -375,7 +376,7 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
> if (retval < 0)
> goto error;
>
> - retval = arch_setup_additional_pages(bprm, !!interpreter_name);
> + retval = arch_setup_additional_pages(&sysinfo_ehdr);
> if (retval < 0)
> goto error;
> #endif
> diff --git a/include/linux/elf.h b/include/linux/elf.h
> index 95bf7a1abaef..a8bea5611a4b 100644
> --- a/include/linux/elf.h
> +++ b/include/linux/elf.h
> @@ -104,13 +104,20 @@ static inline int arch_elf_adjust_prot(int prot,
> }
> #endif
>
> -struct linux_binprm;
> #ifdef CONFIG_ARCH_HAS_SETUP_ADDITIONAL_PAGES
> -extern int arch_setup_additional_pages(struct linux_binprm *bprm,
> - int uses_interp);
> +/**
> + * arch_setup_additional_pages - Premap VMAs in a new-execed process
> + * @sysinfo_ehdr: Returns vDSO position to be set in the initial
> + * auxiliary vector (tag AT_SYSINFO_EHDR) by binfmt
> + * loader. On failure isn't initialized.
> + * As address == 0 is never used, it allows to check
> + * if the tag should be set.
> + *
> + * Return: Zero if successful, or a negative error code on failure.
> + */
> +extern int arch_setup_additional_pages(unsigned long *sysinfo_ehdr);
> #else
> -static inline int arch_setup_additional_pages(struct linux_binprm *bprm,
> - int uses_interp)
> +static inline int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
> {
> return 0;
> }
>