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

Dmitry Safonov
2020-11-24T00:30:31Z

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;
}
--
2.29.2