Re: [PATCH 1/3] mm: Make arch_get_unmapped_area() take vm_flags by default
Lorenzo Stoakes <[email protected]>
| Newsgroups | gmane.linux.ports.ppc64.devel,gmane.linux.ports.arm.kernel,gmane.linux.ports.alpha,gmane.linux.kernel,gmane.linux.kernel.arc,gmane.linux.ports.parisc,gmane.linux.ports.sh.devel,gmane.linux.ports.sparc,gmane.linux.kernel.mm |
|---|---|
| Message-ID | <[email protected]> |
On Mon, Sep 02, 2024 at 08:08:13PM GMT, Mark Brown wrote:
> When we introduced arch_get_unmapped_area_vmflags() in 961148704acd
> ("mm: introduce arch_get_unmapped_area_vmflags()") we did so as part of
> properly supporting guard pages for shadow stacks on x86_64, which uses
> a custom arch_get_unmapped_area(). Equivalent features are also present
> on both arm64 and RISC-V, both of which use the generic implementation
> of arch_get_unmapped_area() and will require equivalent modification
> there. Rather than continue to deal with having two versions of the
> functions let's bite the bullet and have all implementations of
> arch_get_unmapped_area() take vm_flags as a parameter.
>
> The new parameter is currently ignored by all implementations other than
> x86. The only caller that doesn't have a vm_flags available is
> mm_get_unmapped_area(), as for the x86 implementation and the wrapper used
> on other architectures this is modified to supply no flags.
>
> No functional changes.
>
> Signed-off-by: Mark Brown <[email protected]>
mm/mmap.c bit looks reasonable to me! Nice cleanup! :)
Acked-by: Lorenzo Stoakes <[email protected]> (for mm/mmap.c part)
> ---
> arch/alpha/kernel/osf_sys.c | 2 +-
> arch/arc/mm/mmap.c | 3 ++-
> arch/arm/mm/mmap.c | 7 ++++---
> arch/csky/abiv1/mmap.c | 3 ++-
> arch/loongarch/mm/mmap.c | 5 +++--
> arch/mips/mm/mmap.c | 2 +-
> arch/parisc/kernel/sys_parisc.c | 5 +++--
> arch/parisc/mm/hugetlbpage.c | 2 +-
> arch/powerpc/mm/book3s64/slice.c | 6 ++++--
> arch/s390/mm/mmap.c | 4 ++--
> arch/sh/mm/mmap.c | 5 +++--
> arch/sparc/kernel/sys_sparc_32.c | 2 +-
> arch/sparc/kernel/sys_sparc_64.c | 4 ++--
> arch/x86/include/asm/pgtable_64.h | 1 -
> arch/x86/kernel/sys_x86_64.c | 21 +++------------------
> arch/xtensa/kernel/syscall.c | 3 ++-
> include/linux/sched/mm.h | 23 ++++++++---------------
> mm/mmap.c | 31 +++++++------------------------
> 18 files changed, 49 insertions(+), 80 deletions(-)
>
> diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
> index e5f881bc8288..8886ab539273 100644
> --- a/arch/alpha/kernel/osf_sys.c
> +++ b/arch/alpha/kernel/osf_sys.c
> @@ -1229,7 +1229,7 @@ arch_get_unmapped_area_1(unsigned long addr, unsigned long len,
> unsigned long
> arch_get_unmapped_area(struct file *filp, unsigned long addr,
> unsigned long len, unsigned long pgoff,
> - unsigned long flags)
> + unsigned long flags, vm_flags_t vm_flags)
> {
> unsigned long limit;
>
> diff --git a/arch/arc/mm/mmap.c b/arch/arc/mm/mmap.c
> index 69a915297155..2185afe8d59f 100644
> --- a/arch/arc/mm/mmap.c
> +++ b/arch/arc/mm/mmap.c
> @@ -23,7 +23,8 @@
> */
> unsigned long
> arch_get_unmapped_area(struct file *filp, unsigned long addr,
> - unsigned long len, unsigned long pgoff, unsigned long flags)
> + unsigned long len, unsigned long pgoff,
> + unsigned long flags, vm_flags_t vm_flags)
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
> index d65d0e6ed10a..3dbb383c26d5 100644
> --- a/arch/arm/mm/mmap.c
> +++ b/arch/arm/mm/mmap.c
> @@ -28,7 +28,8 @@
> */
> unsigned long
> arch_get_unmapped_area(struct file *filp, unsigned long addr,
> - unsigned long len, unsigned long pgoff, unsigned long flags)
> + unsigned long len, unsigned long pgoff,
> + unsigned long flags, vm_flags_t vm_flags)
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> @@ -78,8 +79,8 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
>
> unsigned long
> arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
> - const unsigned long len, const unsigned long pgoff,
> - const unsigned long flags)
> + const unsigned long len, const unsigned long pgoff,
> + const unsigned long flags, vm_flags_t vm_flags)
> {
> struct vm_area_struct *vma;
> struct mm_struct *mm = current->mm;
> diff --git a/arch/csky/abiv1/mmap.c b/arch/csky/abiv1/mmap.c
> index 7f826331d409..1047865e82a9 100644
> --- a/arch/csky/abiv1/mmap.c
> +++ b/arch/csky/abiv1/mmap.c
> @@ -23,7 +23,8 @@
> */
> unsigned long
> arch_get_unmapped_area(struct file *filp, unsigned long addr,
> - unsigned long len, unsigned long pgoff, unsigned long flags)
> + unsigned long len, unsigned long pgoff,
> + unsigned long flags, vm_flags_t vm_flags)
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> diff --git a/arch/loongarch/mm/mmap.c b/arch/loongarch/mm/mmap.c
> index 889030985135..914e82ff3f65 100644
> --- a/arch/loongarch/mm/mmap.c
> +++ b/arch/loongarch/mm/mmap.c
> @@ -89,7 +89,8 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp,
> }
>
> unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0,
> - unsigned long len, unsigned long pgoff, unsigned long flags)
> + unsigned long len, unsigned long pgoff, unsigned long flags,
> + vm_flags_t vm_flags)
> {
> return arch_get_unmapped_area_common(filp,
> addr0, len, pgoff, flags, UP);
> @@ -101,7 +102,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0,
> */
> unsigned long arch_get_unmapped_area_topdown(struct file *filp,
> unsigned long addr0, unsigned long len, unsigned long pgoff,
> - unsigned long flags)
> + unsigned long flags, vm_flags_t vm_flags)
> {
> return arch_get_unmapped_area_common(filp,
> addr0, len, pgoff, flags, DOWN);
> diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c
> index 7e11d7b58761..02bf5353efbd 100644
> --- a/arch/mips/mm/mmap.c
> +++ b/arch/mips/mm/mmap.c
> @@ -110,7 +110,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0,
> */
> unsigned long arch_get_unmapped_area_topdown(struct file *filp,
> unsigned long addr0, unsigned long len, unsigned long pgoff,
> - unsigned long flags)
> + unsigned long flags, vm_flags_t vm_flags)
> {
> return arch_get_unmapped_area_common(filp,
> addr0, len, pgoff, flags, DOWN);
> diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
> index f7722451276e..f852fe274abe 100644
> --- a/arch/parisc/kernel/sys_parisc.c
> +++ b/arch/parisc/kernel/sys_parisc.c
> @@ -167,7 +167,8 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp,
> }
>
> unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
> - unsigned long len, unsigned long pgoff, unsigned long flags)
> + unsigned long len, unsigned long pgoff, unsigned long flags,
> + vm_flags_t vm_flags)
> {
> return arch_get_unmapped_area_common(filp,
> addr, len, pgoff, flags, UP);
> @@ -175,7 +176,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
>
> unsigned long arch_get_unmapped_area_topdown(struct file *filp,
> unsigned long addr, unsigned long len, unsigned long pgoff,
> - unsigned long flags)
> + unsigned long flags, vm_flags_t vm_flags)
> {
> return arch_get_unmapped_area_common(filp,
> addr, len, pgoff, flags, DOWN);
> diff --git a/arch/parisc/mm/hugetlbpage.c b/arch/parisc/mm/hugetlbpage.c
> index 0356199bd9e7..aa664f7ddb63 100644
> --- a/arch/parisc/mm/hugetlbpage.c
> +++ b/arch/parisc/mm/hugetlbpage.c
> @@ -40,7 +40,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
> addr = ALIGN(addr, huge_page_size(h));
>
> /* we need to make sure the colouring is OK */
> - return arch_get_unmapped_area(file, addr, len, pgoff, flags);
> + return arch_get_unmapped_area(file, addr, len, pgoff, flags, 0);
> }
>
>
> diff --git a/arch/powerpc/mm/book3s64/slice.c b/arch/powerpc/mm/book3s64/slice.c
> index ef3ce37f1bb3..ada6bf896ef8 100644
> --- a/arch/powerpc/mm/book3s64/slice.c
> +++ b/arch/powerpc/mm/book3s64/slice.c
> @@ -637,7 +637,8 @@ unsigned long arch_get_unmapped_area(struct file *filp,
> unsigned long addr,
> unsigned long len,
> unsigned long pgoff,
> - unsigned long flags)
> + unsigned long flags,
> + vm_flags_t vm_flags)
> {
> if (radix_enabled())
> return generic_get_unmapped_area(filp, addr, len, pgoff, flags);
> @@ -650,7 +651,8 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp,
> const unsigned long addr0,
> const unsigned long len,
> const unsigned long pgoff,
> - const unsigned long flags)
> + const unsigned long flags,
> + vm_flags_t vm_flags)
> {
> if (radix_enabled())
> return generic_get_unmapped_area_topdown(filp, addr0, len, pgoff, flags);
> diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
> index 206756946589..96efa061ce01 100644
> --- a/arch/s390/mm/mmap.c
> +++ b/arch/s390/mm/mmap.c
> @@ -82,7 +82,7 @@ static int get_align_mask(struct file *filp, unsigned long flags)
>
> unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
> unsigned long len, unsigned long pgoff,
> - unsigned long flags)
> + unsigned long flags, vm_flags_t vm_flags)
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> @@ -117,7 +117,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
>
> unsigned long arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
> unsigned long len, unsigned long pgoff,
> - unsigned long flags)
> + unsigned long flags, vm_flags_t vm_flags)
> {
> struct vm_area_struct *vma;
> struct mm_struct *mm = current->mm;
> diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c
> index bee329d4149a..c442734d9b0c 100644
> --- a/arch/sh/mm/mmap.c
> +++ b/arch/sh/mm/mmap.c
> @@ -52,7 +52,8 @@ static inline unsigned long COLOUR_ALIGN(unsigned long addr,
> }
>
> unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
> - unsigned long len, unsigned long pgoff, unsigned long flags)
> + unsigned long len, unsigned long pgoff, unsigned long flags,
> + vm_flags_t vm_flags)
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma;
> @@ -99,7 +100,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
> unsigned long
> arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
> const unsigned long len, const unsigned long pgoff,
> - const unsigned long flags)
> + const unsigned long flags, vm_flags_t vm_flags)
> {
> struct vm_area_struct *vma;
> struct mm_struct *mm = current->mm;
> diff --git a/arch/sparc/kernel/sys_sparc_32.c b/arch/sparc/kernel/sys_sparc_32.c
> index 08a19727795c..80822f922e76 100644
> --- a/arch/sparc/kernel/sys_sparc_32.c
> +++ b/arch/sparc/kernel/sys_sparc_32.c
> @@ -39,7 +39,7 @@ SYSCALL_DEFINE0(getpagesize)
> return PAGE_SIZE; /* Possibly older binaries want 8192 on sun4's? */
> }
>
> -unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
> +unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags)
> {
> struct vm_unmapped_area_info info = {};
>
> diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
> index d9c3b34ca744..acade309dc2f 100644
> --- a/arch/sparc/kernel/sys_sparc_64.c
> +++ b/arch/sparc/kernel/sys_sparc_64.c
> @@ -87,7 +87,7 @@ static inline unsigned long COLOR_ALIGN(unsigned long addr,
> return base + off;
> }
>
> -unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
> +unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags)
> {
> struct mm_struct *mm = current->mm;
> struct vm_area_struct * vma;
> @@ -146,7 +146,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
> unsigned long
> arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
> const unsigned long len, const unsigned long pgoff,
> - const unsigned long flags)
> + const unsigned long flags, vm_flags_t vm_flags)
> {
> struct vm_area_struct *vma;
> struct mm_struct *mm = current->mm;
> diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
> index 3c4407271d08..7e9db77231ac 100644
> --- a/arch/x86/include/asm/pgtable_64.h
> +++ b/arch/x86/include/asm/pgtable_64.h
> @@ -245,7 +245,6 @@ extern void cleanup_highmap(void);
>
> #define HAVE_ARCH_UNMAPPED_AREA
> #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
> -#define HAVE_ARCH_UNMAPPED_AREA_VMFLAGS
>
> #define PAGE_AGP PAGE_KERNEL_NOCACHE
> #define HAVE_PAGE_AGP 1
> diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
> index 01d7cd85ef97..87f8c9a71c49 100644
> --- a/arch/x86/kernel/sys_x86_64.c
> +++ b/arch/x86/kernel/sys_x86_64.c
> @@ -121,7 +121,7 @@ static inline unsigned long stack_guard_placement(vm_flags_t vm_flags)
> }
>
> unsigned long
> -arch_get_unmapped_area_vmflags(struct file *filp, unsigned long addr, unsigned long len,
> +arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len,
> unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags)
> {
> struct mm_struct *mm = current->mm;
> @@ -158,7 +158,7 @@ arch_get_unmapped_area_vmflags(struct file *filp, unsigned long addr, unsigned l
> }
>
> unsigned long
> -arch_get_unmapped_area_topdown_vmflags(struct file *filp, unsigned long addr0,
> +arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr0,
> unsigned long len, unsigned long pgoff,
> unsigned long flags, vm_flags_t vm_flags)
> {
> @@ -228,20 +228,5 @@ arch_get_unmapped_area_topdown_vmflags(struct file *filp, unsigned long addr0,
> * can happen with large stack limits and large mmap()
> * allocations.
> */
> - return arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
> -}
> -
> -unsigned long
> -arch_get_unmapped_area(struct file *filp, unsigned long addr,
> - unsigned long len, unsigned long pgoff, unsigned long flags)
> -{
> - return arch_get_unmapped_area_vmflags(filp, addr, len, pgoff, flags, 0);
> -}
> -
> -unsigned long
> -arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr,
> - const unsigned long len, const unsigned long pgoff,
> - const unsigned long flags)
> -{
> - return arch_get_unmapped_area_topdown_vmflags(filp, addr, len, pgoff, flags, 0);
> + return arch_get_unmapped_area(filp, addr0, len, pgoff, flags, 0);
> }
> diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c
> index b3c2450d6f23..7f048d368dba 100644
> --- a/arch/xtensa/kernel/syscall.c
> +++ b/arch/xtensa/kernel/syscall.c
> @@ -55,7 +55,8 @@ asmlinkage long xtensa_fadvise64_64(int fd, int advice,
>
> #ifdef CONFIG_MMU
> unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
> - unsigned long len, unsigned long pgoff, unsigned long flags)
> + unsigned long len, unsigned long pgoff, unsigned long flags,
> + vm_flgs_t vm_flags)
> {
> struct vm_area_struct *vmm;
> struct vma_iterator vmi;
> diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
> index 91546493c43d..c4d34abc45d4 100644
> --- a/include/linux/sched/mm.h
> +++ b/include/linux/sched/mm.h
> @@ -179,27 +179,20 @@ static inline void mm_update_next_owner(struct mm_struct *mm)
>
> extern void arch_pick_mmap_layout(struct mm_struct *mm,
> struct rlimit *rlim_stack);
> -extern unsigned long
> -arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
> - unsigned long, unsigned long);
> -extern unsigned long
> +
> +unsigned long
> +arch_get_unmapped_area(struct file *filp, unsigned long addr,
> + unsigned long len, unsigned long pgoff,
> + unsigned long flags, vm_flags_t vm_flags);
> +unsigned long
> arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
> - unsigned long len, unsigned long pgoff,
> - unsigned long flags);
> + unsigned long len, unsigned long pgoff,
> + unsigned long flags, vm_flags_t);
>
> unsigned long mm_get_unmapped_area(struct mm_struct *mm, struct file *filp,
> unsigned long addr, unsigned long len,
> unsigned long pgoff, unsigned long flags);
>
> -unsigned long
> -arch_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
> - unsigned long len, unsigned long pgoff,
> - unsigned long flags, vm_flags_t vm_flags);
> -unsigned long
> -arch_get_unmapped_area_topdown_vmflags(struct file *filp, unsigned long addr,
> - unsigned long len, unsigned long pgoff,
> - unsigned long flags, vm_flags_t);
> -
> unsigned long mm_get_unmapped_area_vmflags(struct mm_struct *mm,
> struct file *filp,
> unsigned long addr,
> diff --git a/mm/mmap.c b/mm/mmap.c
> index d0dfc85b209b..7528146f886f 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -1821,7 +1821,7 @@ generic_get_unmapped_area(struct file *filp, unsigned long addr,
> unsigned long
> arch_get_unmapped_area(struct file *filp, unsigned long addr,
> unsigned long len, unsigned long pgoff,
> - unsigned long flags)
> + unsigned long flags, vm_flags_t vm_flags)
> {
> return generic_get_unmapped_area(filp, addr, len, pgoff, flags);
> }
> @@ -1885,38 +1885,21 @@ generic_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
> unsigned long
> arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
> unsigned long len, unsigned long pgoff,
> - unsigned long flags)
> + unsigned long flags, vm_flags_t vm_flags)
> {
> return generic_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
> }
> #endif
>
> -#ifndef HAVE_ARCH_UNMAPPED_AREA_VMFLAGS
> -unsigned long
> -arch_get_unmapped_area_vmflags(struct file *filp, unsigned long addr, unsigned long len,
> - unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags)
> -{
> - return arch_get_unmapped_area(filp, addr, len, pgoff, flags);
> -}
> -
> -unsigned long
> -arch_get_unmapped_area_topdown_vmflags(struct file *filp, unsigned long addr,
> - unsigned long len, unsigned long pgoff,
> - unsigned long flags, vm_flags_t vm_flags)
> -{
> - return arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
> -}
> -#endif
> -
> unsigned long mm_get_unmapped_area_vmflags(struct mm_struct *mm, struct file *filp,
> unsigned long addr, unsigned long len,
> unsigned long pgoff, unsigned long flags,
> vm_flags_t vm_flags)
> {
> if (test_bit(MMF_TOPDOWN, &mm->flags))
> - return arch_get_unmapped_area_topdown_vmflags(filp, addr, len, pgoff,
> - flags, vm_flags);
> - return arch_get_unmapped_area_vmflags(filp, addr, len, pgoff, flags, vm_flags);
> + return arch_get_unmapped_area_topdown(filp, addr, len, pgoff,
> + flags, vm_flags);
> + return arch_get_unmapped_area(filp, addr, len, pgoff, flags, vm_flags);
> }
Kind of a pity to keep the _vmflags() variants when in similarly-named
arch_get_unmapped...() functions we drop it, but I guess it would get churny to
try to change mm_get_unmapped_area() as I see that being called in various places.
>
> unsigned long
> @@ -1978,8 +1961,8 @@ mm_get_unmapped_area(struct mm_struct *mm, struct file *file,
> unsigned long pgoff, unsigned long flags)
> {
> if (test_bit(MMF_TOPDOWN, &mm->flags))
> - return arch_get_unmapped_area_topdown(file, addr, len, pgoff, flags);
> - return arch_get_unmapped_area(file, addr, len, pgoff, flags);
> + return arch_get_unmapped_area_topdown(file, addr, len, pgoff, flags, 0);
> + return arch_get_unmapped_area(file, addr, len, pgoff, flags, 0);
> }
> EXPORT_SYMBOL(mm_get_unmapped_area);
>
>
> --
> 2.39.2
>