diff mbox series

[V6,17/20] riscv: compat: vdso: Add setup additional pages implementation

Message ID 20220224085410.399351-18-guoren@kernel.org (mailing list archive)
State Not Applicable
Headers show
Series riscv: compat: Add COMPAT mode support for rv64 | expand

Commit Message

Guo Ren Feb. 24, 2022, 8:54 a.m. UTC
From: Guo Ren <guoren@linux.alibaba.com>

Reconstruct __setup_additional_pages() by appending vdso info
pointer argument to meet compat_vdso_info requirement. And change
vm_special_mapping *dm, *cm initialization into static.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Arnd Bergmann <arnd@arndb.de>
---
 arch/riscv/include/asm/elf.h |   5 ++
 arch/riscv/include/asm/mmu.h |   1 +
 arch/riscv/kernel/vdso.c     | 103 +++++++++++++++++++++++------------
 3 files changed, 74 insertions(+), 35 deletions(-)

Comments

Palmer Dabbelt Feb. 24, 2022, 5:57 p.m. UTC | #1
On Thu, 24 Feb 2022 00:54:07 PST (-0800), guoren@kernel.org wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
>
> Reconstruct __setup_additional_pages() by appending vdso info
> pointer argument to meet compat_vdso_info requirement. And change
> vm_special_mapping *dm, *cm initialization into static.
>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>
> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> ---
>  arch/riscv/include/asm/elf.h |   5 ++
>  arch/riscv/include/asm/mmu.h |   1 +
>  arch/riscv/kernel/vdso.c     | 103 +++++++++++++++++++++++------------
>  3 files changed, 74 insertions(+), 35 deletions(-)
>
> diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
> index 3a4293dc7229..d87d3bcc758d 100644
> --- a/arch/riscv/include/asm/elf.h
> +++ b/arch/riscv/include/asm/elf.h
> @@ -134,5 +134,10 @@ do {    if ((ex).e_ident[EI_CLASS] == ELFCLASS32)		\
>  typedef compat_ulong_t			compat_elf_greg_t;
>  typedef compat_elf_greg_t		compat_elf_gregset_t[ELF_NGREG];
>
> +extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
> +					      int uses_interp);
> +#define compat_arch_setup_additional_pages \
> +				compat_arch_setup_additional_pages
> +
>  #endif /* CONFIG_COMPAT */
>  #endif /* _ASM_RISCV_ELF_H */
> diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h
> index 0099dc116168..cedcf8ea3c76 100644
> --- a/arch/riscv/include/asm/mmu.h
> +++ b/arch/riscv/include/asm/mmu.h
> @@ -16,6 +16,7 @@ typedef struct {
>  	atomic_long_t id;
>  #endif
>  	void *vdso;
> +	void *vdso_info;
>  #ifdef CONFIG_SMP
>  	/* A local icache flush is needed before user execution can resume. */
>  	cpumask_t icache_stale_mask;
> diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c
> index a9436a65161a..f864811aa011 100644
> --- a/arch/riscv/kernel/vdso.c
> +++ b/arch/riscv/kernel/vdso.c
> @@ -23,6 +23,9 @@ struct vdso_data {
>  #endif
>
>  extern char vdso_start[], vdso_end[];
> +#ifdef CONFIG_COMPAT
> +extern char compat_vdso_start[], compat_vdso_end[];
> +#endif
>
>  enum vvar_pages {
>  	VVAR_DATA_PAGE_OFFSET,
> @@ -30,6 +33,11 @@ enum vvar_pages {
>  	VVAR_NR_PAGES,
>  };
>
> +enum rv_vdso_map {
> +	RV_VDSO_MAP_VVAR,
> +	RV_VDSO_MAP_VDSO,
> +};
> +
>  #define VVAR_SIZE  (VVAR_NR_PAGES << PAGE_SHIFT)
>
>  /*
> @@ -52,12 +60,6 @@ struct __vdso_info {
>  	struct vm_special_mapping *cm;
>  };
>
> -static struct __vdso_info vdso_info __ro_after_init = {
> -	.name = "vdso",
> -	.vdso_code_start = vdso_start,
> -	.vdso_code_end = vdso_end,
> -};
> -
>  static int vdso_mremap(const struct vm_special_mapping *sm,
>  		       struct vm_area_struct *new_vma)
>  {
> @@ -66,37 +68,33 @@ static int vdso_mremap(const struct vm_special_mapping *sm,
>  	return 0;
>  }
>
> -static int __init __vdso_init(void)
> +static void __init __vdso_init(struct __vdso_info *vdso_info)
>  {
>  	unsigned int i;
>  	struct page **vdso_pagelist;
>  	unsigned long pfn;
>
> -	if (memcmp(vdso_info.vdso_code_start, "\177ELF", 4)) {
> -		pr_err("vDSO is not a valid ELF object!\n");
> -		return -EINVAL;
> -	}
> +	if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4))
> +		panic("vDSO is not a valid ELF object!\n");
>
> -	vdso_info.vdso_pages = (
> -		vdso_info.vdso_code_end -
> -		vdso_info.vdso_code_start) >>
> +	vdso_info->vdso_pages = (
> +		vdso_info->vdso_code_end -
> +		vdso_info->vdso_code_start) >>
>  		PAGE_SHIFT;
>
> -	vdso_pagelist = kcalloc(vdso_info.vdso_pages,
> +	vdso_pagelist = kcalloc(vdso_info->vdso_pages,
>  				sizeof(struct page *),
>  				GFP_KERNEL);
>  	if (vdso_pagelist == NULL)
> -		return -ENOMEM;
> +		panic("vDSO kcalloc failed!\n");
>
>  	/* Grab the vDSO code pages. */
> -	pfn = sym_to_pfn(vdso_info.vdso_code_start);
> +	pfn = sym_to_pfn(vdso_info->vdso_code_start);
>
> -	for (i = 0; i < vdso_info.vdso_pages; i++)
> +	for (i = 0; i < vdso_info->vdso_pages; i++)
>  		vdso_pagelist[i] = pfn_to_page(pfn + i);
>
> -	vdso_info.cm->pages = vdso_pagelist;
> -
> -	return 0;
> +	vdso_info->cm->pages = vdso_pagelist;
>  }
>
>  #ifdef CONFIG_TIME_NS
> @@ -116,13 +114,14 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
>  {
>  	struct mm_struct *mm = task->mm;
>  	struct vm_area_struct *vma;
> +	struct __vdso_info *vdso_info = mm->context.vdso_info;
>
>  	mmap_read_lock(mm);
>
>  	for (vma = mm->mmap; vma; vma = vma->vm_next) {
>  		unsigned long size = vma->vm_end - vma->vm_start;
>
> -		if (vma_is_special_mapping(vma, vdso_info.dm))
> +		if (vma_is_special_mapping(vma, vdso_info->dm))
>  			zap_page_range(vma, vma->vm_start, size);
>  	}
>
> @@ -187,11 +186,6 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
>  	return vmf_insert_pfn(vma, vmf->address, pfn);
>  }
>
> -enum rv_vdso_map {
> -	RV_VDSO_MAP_VVAR,
> -	RV_VDSO_MAP_VDSO,
> -};
> -
>  static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = {
>  	[RV_VDSO_MAP_VVAR] = {
>  		.name   = "[vvar]",
> @@ -203,25 +197,44 @@ static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = {
>  	},
>  };
>
> +static struct __vdso_info vdso_info __ro_after_init = {
> +	.name = "vdso",
> +	.vdso_code_start = vdso_start,
> +	.vdso_code_end = vdso_end,
> +	.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR],
> +	.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO],
> +};
> +
> +#ifdef CONFIG_COMPAT
> +static struct __vdso_info compat_vdso_info __ro_after_init = {
> +	.name = "compat_vdso",
> +	.vdso_code_start = compat_vdso_start,
> +	.vdso_code_end = compat_vdso_end,
> +	.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR],
> +	.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO],
> +};
> +#endif
> +
>  static int __init vdso_init(void)
>  {
> -	vdso_info.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR];
> -	vdso_info.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO];
> +	__vdso_init(&vdso_info);
> +	__vdso_init(&compat_vdso_info);

An autobuilder is pointing out an issue here.  I'm assuming just an `#if 
defined(CONFIG_COMPAT)` will fix it, I'm OK squashing that in if it's 
the only issue -- a fixed one never hurts, though ;)

I'll try to take another look soon.

> -	return __vdso_init();
> +	return 0;
>  }
>  arch_initcall(vdso_init);
>
>  static int __setup_additional_pages(struct mm_struct *mm,
>  				    struct linux_binprm *bprm,
> -				    int uses_interp)
> +				    int uses_interp,
> +				    struct __vdso_info *vdso_info)
>  {
>  	unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
>  	void *ret;
>
>  	BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
>
> -	vdso_text_len = vdso_info.vdso_pages << PAGE_SHIFT;
> +	vdso_text_len = vdso_info->vdso_pages << PAGE_SHIFT;
>  	/* Be sure to map the data page */
>  	vdso_mapping_len = vdso_text_len + VVAR_SIZE;
>
> @@ -232,16 +245,18 @@ static int __setup_additional_pages(struct mm_struct *mm,
>  	}
>
>  	ret = _install_special_mapping(mm, vdso_base, VVAR_SIZE,
> -		(VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info.dm);
> +		(VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info->dm);
>  	if (IS_ERR(ret))
>  		goto up_fail;
>
>  	vdso_base += VVAR_SIZE;
>  	mm->context.vdso = (void *)vdso_base;
> +	mm->context.vdso_info = (void *)vdso_info;
> +
>  	ret =
>  	   _install_special_mapping(mm, vdso_base, vdso_text_len,
>  		(VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
> -		vdso_info.cm);
> +		vdso_info->cm);
>
>  	if (IS_ERR(ret))
>  		goto up_fail;
> @@ -253,6 +268,24 @@ static int __setup_additional_pages(struct mm_struct *mm,
>  	return PTR_ERR(ret);
>  }
>
> +#ifdef CONFIG_COMPAT
> +int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
> +				       int uses_interp)
> +{
> +	struct mm_struct *mm = current->mm;
> +	int ret;
> +
> +	if (mmap_write_lock_killable(mm))
> +		return -EINTR;
> +
> +	ret = __setup_additional_pages(mm, bprm, uses_interp,
> +							&compat_vdso_info);
> +	mmap_write_unlock(mm);
> +
> +	return ret;
> +}
> +#endif
> +
>  int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
>  {
>  	struct mm_struct *mm = current->mm;
> @@ -261,7 +294,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
>  	if (mmap_write_lock_killable(mm))
>  		return -EINTR;
>
> -	ret = __setup_additional_pages(mm, bprm, uses_interp);
> +	ret = __setup_additional_pages(mm, bprm, uses_interp, &vdso_info);
>  	mmap_write_unlock(mm);
>
>  	return ret;
Guo Ren Feb. 25, 2022, 3:15 a.m. UTC | #2
On Fri, Feb 25, 2022 at 1:57 AM Palmer Dabbelt <palmer@dabbelt.com> wrote:
>
> On Thu, 24 Feb 2022 00:54:07 PST (-0800), guoren@kernel.org wrote:
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > Reconstruct __setup_additional_pages() by appending vdso info
> > pointer argument to meet compat_vdso_info requirement. And change
> > vm_special_mapping *dm, *cm initialization into static.
> >
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Signed-off-by: Guo Ren <guoren@kernel.org>
> > Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > ---
> >  arch/riscv/include/asm/elf.h |   5 ++
> >  arch/riscv/include/asm/mmu.h |   1 +
> >  arch/riscv/kernel/vdso.c     | 103 +++++++++++++++++++++++------------
> >  3 files changed, 74 insertions(+), 35 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
> > index 3a4293dc7229..d87d3bcc758d 100644
> > --- a/arch/riscv/include/asm/elf.h
> > +++ b/arch/riscv/include/asm/elf.h
> > @@ -134,5 +134,10 @@ do {    if ((ex).e_ident[EI_CLASS] == ELFCLASS32)                \
> >  typedef compat_ulong_t                       compat_elf_greg_t;
> >  typedef compat_elf_greg_t            compat_elf_gregset_t[ELF_NGREG];
> >
> > +extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
> > +                                           int uses_interp);
> > +#define compat_arch_setup_additional_pages \
> > +                             compat_arch_setup_additional_pages
> > +
> >  #endif /* CONFIG_COMPAT */
> >  #endif /* _ASM_RISCV_ELF_H */
> > diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h
> > index 0099dc116168..cedcf8ea3c76 100644
> > --- a/arch/riscv/include/asm/mmu.h
> > +++ b/arch/riscv/include/asm/mmu.h
> > @@ -16,6 +16,7 @@ typedef struct {
> >       atomic_long_t id;
> >  #endif
> >       void *vdso;
> > +     void *vdso_info;
> >  #ifdef CONFIG_SMP
> >       /* A local icache flush is needed before user execution can resume. */
> >       cpumask_t icache_stale_mask;
> > diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c
> > index a9436a65161a..f864811aa011 100644
> > --- a/arch/riscv/kernel/vdso.c
> > +++ b/arch/riscv/kernel/vdso.c
> > @@ -23,6 +23,9 @@ struct vdso_data {
> >  #endif
> >
> >  extern char vdso_start[], vdso_end[];
> > +#ifdef CONFIG_COMPAT
> > +extern char compat_vdso_start[], compat_vdso_end[];
> > +#endif
> >
> >  enum vvar_pages {
> >       VVAR_DATA_PAGE_OFFSET,
> > @@ -30,6 +33,11 @@ enum vvar_pages {
> >       VVAR_NR_PAGES,
> >  };
> >
> > +enum rv_vdso_map {
> > +     RV_VDSO_MAP_VVAR,
> > +     RV_VDSO_MAP_VDSO,
> > +};
> > +
> >  #define VVAR_SIZE  (VVAR_NR_PAGES << PAGE_SHIFT)
> >
> >  /*
> > @@ -52,12 +60,6 @@ struct __vdso_info {
> >       struct vm_special_mapping *cm;
> >  };
> >
> > -static struct __vdso_info vdso_info __ro_after_init = {
> > -     .name = "vdso",
> > -     .vdso_code_start = vdso_start,
> > -     .vdso_code_end = vdso_end,
> > -};
> > -
> >  static int vdso_mremap(const struct vm_special_mapping *sm,
> >                      struct vm_area_struct *new_vma)
> >  {
> > @@ -66,37 +68,33 @@ static int vdso_mremap(const struct vm_special_mapping *sm,
> >       return 0;
> >  }
> >
> > -static int __init __vdso_init(void)
> > +static void __init __vdso_init(struct __vdso_info *vdso_info)
> >  {
> >       unsigned int i;
> >       struct page **vdso_pagelist;
> >       unsigned long pfn;
> >
> > -     if (memcmp(vdso_info.vdso_code_start, "\177ELF", 4)) {
> > -             pr_err("vDSO is not a valid ELF object!\n");
> > -             return -EINVAL;
> > -     }
> > +     if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4))
> > +             panic("vDSO is not a valid ELF object!\n");
> >
> > -     vdso_info.vdso_pages = (
> > -             vdso_info.vdso_code_end -
> > -             vdso_info.vdso_code_start) >>
> > +     vdso_info->vdso_pages = (
> > +             vdso_info->vdso_code_end -
> > +             vdso_info->vdso_code_start) >>
> >               PAGE_SHIFT;
> >
> > -     vdso_pagelist = kcalloc(vdso_info.vdso_pages,
> > +     vdso_pagelist = kcalloc(vdso_info->vdso_pages,
> >                               sizeof(struct page *),
> >                               GFP_KERNEL);
> >       if (vdso_pagelist == NULL)
> > -             return -ENOMEM;
> > +             panic("vDSO kcalloc failed!\n");
> >
> >       /* Grab the vDSO code pages. */
> > -     pfn = sym_to_pfn(vdso_info.vdso_code_start);
> > +     pfn = sym_to_pfn(vdso_info->vdso_code_start);
> >
> > -     for (i = 0; i < vdso_info.vdso_pages; i++)
> > +     for (i = 0; i < vdso_info->vdso_pages; i++)
> >               vdso_pagelist[i] = pfn_to_page(pfn + i);
> >
> > -     vdso_info.cm->pages = vdso_pagelist;
> > -
> > -     return 0;
> > +     vdso_info->cm->pages = vdso_pagelist;
> >  }
> >
> >  #ifdef CONFIG_TIME_NS
> > @@ -116,13 +114,14 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
> >  {
> >       struct mm_struct *mm = task->mm;
> >       struct vm_area_struct *vma;
> > +     struct __vdso_info *vdso_info = mm->context.vdso_info;
> >
> >       mmap_read_lock(mm);
> >
> >       for (vma = mm->mmap; vma; vma = vma->vm_next) {
> >               unsigned long size = vma->vm_end - vma->vm_start;
> >
> > -             if (vma_is_special_mapping(vma, vdso_info.dm))
> > +             if (vma_is_special_mapping(vma, vdso_info->dm))
> >                       zap_page_range(vma, vma->vm_start, size);
> >       }
> >
> > @@ -187,11 +186,6 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
> >       return vmf_insert_pfn(vma, vmf->address, pfn);
> >  }
> >
> > -enum rv_vdso_map {
> > -     RV_VDSO_MAP_VVAR,
> > -     RV_VDSO_MAP_VDSO,
> > -};
> > -
> >  static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = {
> >       [RV_VDSO_MAP_VVAR] = {
> >               .name   = "[vvar]",
> > @@ -203,25 +197,44 @@ static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = {
> >       },
> >  };
> >
> > +static struct __vdso_info vdso_info __ro_after_init = {
> > +     .name = "vdso",
> > +     .vdso_code_start = vdso_start,
> > +     .vdso_code_end = vdso_end,
> > +     .dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR],
> > +     .cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO],
> > +};
> > +
> > +#ifdef CONFIG_COMPAT
> > +static struct __vdso_info compat_vdso_info __ro_after_init = {
> > +     .name = "compat_vdso",
> > +     .vdso_code_start = compat_vdso_start,
> > +     .vdso_code_end = compat_vdso_end,
> > +     .dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR],
> > +     .cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO],
> > +};
> > +#endif
> > +
> >  static int __init vdso_init(void)
> >  {
> > -     vdso_info.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR];
> > -     vdso_info.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO];
> > +     __vdso_init(&vdso_info);
> > +     __vdso_init(&compat_vdso_info);
>
> An autobuilder is pointing out an issue here.  I'm assuming just an `#if
> defined(CONFIG_COMPAT)` will fix it, I'm OK squashing that in if it's
> the only issue -- a fixed one never hurts, though ;)
Thx for pointing out, my fault, it should be:
 static int __init vdso_init(void)
 {
        __vdso_init(&vdso_info);
+#ifdef CONFIG_COMPAT
        __vdso_init(&compat_vdso_info);
+#endif

>
> I'll try to take another look soon.
Okay.

>
> > -     return __vdso_init();
> > +     return 0;
> >  }
> >  arch_initcall(vdso_init);
> >
> >  static int __setup_additional_pages(struct mm_struct *mm,
> >                                   struct linux_binprm *bprm,
> > -                                 int uses_interp)
> > +                                 int uses_interp,
> > +                                 struct __vdso_info *vdso_info)
> >  {
> >       unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
> >       void *ret;
> >
> >       BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
> >
> > -     vdso_text_len = vdso_info.vdso_pages << PAGE_SHIFT;
> > +     vdso_text_len = vdso_info->vdso_pages << PAGE_SHIFT;
> >       /* Be sure to map the data page */
> >       vdso_mapping_len = vdso_text_len + VVAR_SIZE;
> >
> > @@ -232,16 +245,18 @@ static int __setup_additional_pages(struct mm_struct *mm,
> >       }
> >
> >       ret = _install_special_mapping(mm, vdso_base, VVAR_SIZE,
> > -             (VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info.dm);
> > +             (VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info->dm);
> >       if (IS_ERR(ret))
> >               goto up_fail;
> >
> >       vdso_base += VVAR_SIZE;
> >       mm->context.vdso = (void *)vdso_base;
> > +     mm->context.vdso_info = (void *)vdso_info;
> > +
> >       ret =
> >          _install_special_mapping(mm, vdso_base, vdso_text_len,
> >               (VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
> > -             vdso_info.cm);
> > +             vdso_info->cm);
> >
> >       if (IS_ERR(ret))
> >               goto up_fail;
> > @@ -253,6 +268,24 @@ static int __setup_additional_pages(struct mm_struct *mm,
> >       return PTR_ERR(ret);
> >  }
> >
> > +#ifdef CONFIG_COMPAT
> > +int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
> > +                                    int uses_interp)
> > +{
> > +     struct mm_struct *mm = current->mm;
> > +     int ret;
> > +
> > +     if (mmap_write_lock_killable(mm))
> > +             return -EINTR;
> > +
> > +     ret = __setup_additional_pages(mm, bprm, uses_interp,
> > +                                                     &compat_vdso_info);
> > +     mmap_write_unlock(mm);
> > +
> > +     return ret;
> > +}
> > +#endif
> > +
> >  int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> >  {
> >       struct mm_struct *mm = current->mm;
> > @@ -261,7 +294,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
> >       if (mmap_write_lock_killable(mm))
> >               return -EINTR;
> >
> > -     ret = __setup_additional_pages(mm, bprm, uses_interp);
> > +     ret = __setup_additional_pages(mm, bprm, uses_interp, &vdso_info);
> >       mmap_write_unlock(mm);
> >
> >       return ret;
diff mbox series

Patch

diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
index 3a4293dc7229..d87d3bcc758d 100644
--- a/arch/riscv/include/asm/elf.h
+++ b/arch/riscv/include/asm/elf.h
@@ -134,5 +134,10 @@  do {    if ((ex).e_ident[EI_CLASS] == ELFCLASS32)		\
 typedef compat_ulong_t			compat_elf_greg_t;
 typedef compat_elf_greg_t		compat_elf_gregset_t[ELF_NGREG];
 
+extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
+					      int uses_interp);
+#define compat_arch_setup_additional_pages \
+				compat_arch_setup_additional_pages
+
 #endif /* CONFIG_COMPAT */
 #endif /* _ASM_RISCV_ELF_H */
diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h
index 0099dc116168..cedcf8ea3c76 100644
--- a/arch/riscv/include/asm/mmu.h
+++ b/arch/riscv/include/asm/mmu.h
@@ -16,6 +16,7 @@  typedef struct {
 	atomic_long_t id;
 #endif
 	void *vdso;
+	void *vdso_info;
 #ifdef CONFIG_SMP
 	/* A local icache flush is needed before user execution can resume. */
 	cpumask_t icache_stale_mask;
diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c
index a9436a65161a..f864811aa011 100644
--- a/arch/riscv/kernel/vdso.c
+++ b/arch/riscv/kernel/vdso.c
@@ -23,6 +23,9 @@  struct vdso_data {
 #endif
 
 extern char vdso_start[], vdso_end[];
+#ifdef CONFIG_COMPAT
+extern char compat_vdso_start[], compat_vdso_end[];
+#endif
 
 enum vvar_pages {
 	VVAR_DATA_PAGE_OFFSET,
@@ -30,6 +33,11 @@  enum vvar_pages {
 	VVAR_NR_PAGES,
 };
 
+enum rv_vdso_map {
+	RV_VDSO_MAP_VVAR,
+	RV_VDSO_MAP_VDSO,
+};
+
 #define VVAR_SIZE  (VVAR_NR_PAGES << PAGE_SHIFT)
 
 /*
@@ -52,12 +60,6 @@  struct __vdso_info {
 	struct vm_special_mapping *cm;
 };
 
-static struct __vdso_info vdso_info __ro_after_init = {
-	.name = "vdso",
-	.vdso_code_start = vdso_start,
-	.vdso_code_end = vdso_end,
-};
-
 static int vdso_mremap(const struct vm_special_mapping *sm,
 		       struct vm_area_struct *new_vma)
 {
@@ -66,37 +68,33 @@  static int vdso_mremap(const struct vm_special_mapping *sm,
 	return 0;
 }
 
-static int __init __vdso_init(void)
+static void __init __vdso_init(struct __vdso_info *vdso_info)
 {
 	unsigned int i;
 	struct page **vdso_pagelist;
 	unsigned long pfn;
 
-	if (memcmp(vdso_info.vdso_code_start, "\177ELF", 4)) {
-		pr_err("vDSO is not a valid ELF object!\n");
-		return -EINVAL;
-	}
+	if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4))
+		panic("vDSO is not a valid ELF object!\n");
 
-	vdso_info.vdso_pages = (
-		vdso_info.vdso_code_end -
-		vdso_info.vdso_code_start) >>
+	vdso_info->vdso_pages = (
+		vdso_info->vdso_code_end -
+		vdso_info->vdso_code_start) >>
 		PAGE_SHIFT;
 
-	vdso_pagelist = kcalloc(vdso_info.vdso_pages,
+	vdso_pagelist = kcalloc(vdso_info->vdso_pages,
 				sizeof(struct page *),
 				GFP_KERNEL);
 	if (vdso_pagelist == NULL)
-		return -ENOMEM;
+		panic("vDSO kcalloc failed!\n");
 
 	/* Grab the vDSO code pages. */
-	pfn = sym_to_pfn(vdso_info.vdso_code_start);
+	pfn = sym_to_pfn(vdso_info->vdso_code_start);
 
-	for (i = 0; i < vdso_info.vdso_pages; i++)
+	for (i = 0; i < vdso_info->vdso_pages; i++)
 		vdso_pagelist[i] = pfn_to_page(pfn + i);
 
-	vdso_info.cm->pages = vdso_pagelist;
-
-	return 0;
+	vdso_info->cm->pages = vdso_pagelist;
 }
 
 #ifdef CONFIG_TIME_NS
@@ -116,13 +114,14 @@  int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
 {
 	struct mm_struct *mm = task->mm;
 	struct vm_area_struct *vma;
+	struct __vdso_info *vdso_info = mm->context.vdso_info;
 
 	mmap_read_lock(mm);
 
 	for (vma = mm->mmap; vma; vma = vma->vm_next) {
 		unsigned long size = vma->vm_end - vma->vm_start;
 
-		if (vma_is_special_mapping(vma, vdso_info.dm))
+		if (vma_is_special_mapping(vma, vdso_info->dm))
 			zap_page_range(vma, vma->vm_start, size);
 	}
 
@@ -187,11 +186,6 @@  static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 	return vmf_insert_pfn(vma, vmf->address, pfn);
 }
 
-enum rv_vdso_map {
-	RV_VDSO_MAP_VVAR,
-	RV_VDSO_MAP_VDSO,
-};
-
 static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = {
 	[RV_VDSO_MAP_VVAR] = {
 		.name   = "[vvar]",
@@ -203,25 +197,44 @@  static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = {
 	},
 };
 
+static struct __vdso_info vdso_info __ro_after_init = {
+	.name = "vdso",
+	.vdso_code_start = vdso_start,
+	.vdso_code_end = vdso_end,
+	.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR],
+	.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO],
+};
+
+#ifdef CONFIG_COMPAT
+static struct __vdso_info compat_vdso_info __ro_after_init = {
+	.name = "compat_vdso",
+	.vdso_code_start = compat_vdso_start,
+	.vdso_code_end = compat_vdso_end,
+	.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR],
+	.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO],
+};
+#endif
+
 static int __init vdso_init(void)
 {
-	vdso_info.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR];
-	vdso_info.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO];
+	__vdso_init(&vdso_info);
+	__vdso_init(&compat_vdso_info);
 
-	return __vdso_init();
+	return 0;
 }
 arch_initcall(vdso_init);
 
 static int __setup_additional_pages(struct mm_struct *mm,
 				    struct linux_binprm *bprm,
-				    int uses_interp)
+				    int uses_interp,
+				    struct __vdso_info *vdso_info)
 {
 	unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
 	void *ret;
 
 	BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
 
-	vdso_text_len = vdso_info.vdso_pages << PAGE_SHIFT;
+	vdso_text_len = vdso_info->vdso_pages << PAGE_SHIFT;
 	/* Be sure to map the data page */
 	vdso_mapping_len = vdso_text_len + VVAR_SIZE;
 
@@ -232,16 +245,18 @@  static int __setup_additional_pages(struct mm_struct *mm,
 	}
 
 	ret = _install_special_mapping(mm, vdso_base, VVAR_SIZE,
-		(VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info.dm);
+		(VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info->dm);
 	if (IS_ERR(ret))
 		goto up_fail;
 
 	vdso_base += VVAR_SIZE;
 	mm->context.vdso = (void *)vdso_base;
+	mm->context.vdso_info = (void *)vdso_info;
+
 	ret =
 	   _install_special_mapping(mm, vdso_base, vdso_text_len,
 		(VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
-		vdso_info.cm);
+		vdso_info->cm);
 
 	if (IS_ERR(ret))
 		goto up_fail;
@@ -253,6 +268,24 @@  static int __setup_additional_pages(struct mm_struct *mm,
 	return PTR_ERR(ret);
 }
 
+#ifdef CONFIG_COMPAT
+int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
+				       int uses_interp)
+{
+	struct mm_struct *mm = current->mm;
+	int ret;
+
+	if (mmap_write_lock_killable(mm))
+		return -EINTR;
+
+	ret = __setup_additional_pages(mm, bprm, uses_interp,
+							&compat_vdso_info);
+	mmap_write_unlock(mm);
+
+	return ret;
+}
+#endif
+
 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 {
 	struct mm_struct *mm = current->mm;
@@ -261,7 +294,7 @@  int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
-	ret = __setup_additional_pages(mm, bprm, uses_interp);
+	ret = __setup_additional_pages(mm, bprm, uses_interp, &vdso_info);
 	mmap_write_unlock(mm);
 
 	return ret;