From: "Mike Rapoport (Microsoft)" <[email protected]> mfill_atomic() passes a lot of parameters down to its callees.
Aggregate them all into mfill_state structure and pass this structure to functions that implement various UFFDIO_ commands. Tracking the state in a structure will allow moving the code that retries copying of data for UFFDIO_COPY into mfill_atomic_pte_copy() and make the loop in mfill_atomic() identical for all UFFDIO operations on PTE-mapped memory. The mfill_state definition is deliberately local to mm/userfaultfd.c, hence shmem_mfill_atomic_pte() is not updated. Signed-off-by: Mike Rapoport (Microsoft) <[email protected]> --- mm/userfaultfd.c | 148 ++++++++++++++++++++++++++--------------------- 1 file changed, 82 insertions(+), 66 deletions(-) diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index a0885d543f22..6a0697c93ff4 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -20,6 +20,20 @@ #include "internal.h" #include "swap.h" +struct mfill_state { + struct userfaultfd_ctx *ctx; + unsigned long src_start; + unsigned long dst_start; + unsigned long len; + uffd_flags_t flags; + + struct vm_area_struct *vma; + unsigned long src_addr; + unsigned long dst_addr; + struct folio *folio; + pmd_t *pmd; +}; + static __always_inline bool validate_dst_vma(struct vm_area_struct *dst_vma, unsigned long dst_end) { @@ -272,17 +286,17 @@ static int mfill_copy_folio_locked(struct folio *folio, unsigned long src_addr) return ret; } -static int mfill_atomic_pte_copy(pmd_t *dst_pmd, - struct vm_area_struct *dst_vma, - unsigned long dst_addr, - unsigned long src_addr, - uffd_flags_t flags, - struct folio **foliop) +static int mfill_atomic_pte_copy(struct mfill_state *state) { - int ret; + struct vm_area_struct *dst_vma = state->vma; + unsigned long dst_addr = state->dst_addr; + unsigned long src_addr = state->src_addr; + uffd_flags_t flags = state->flags; + pmd_t *dst_pmd = state->pmd; struct folio *folio; + int ret; - if (!*foliop) { + if (!state->folio) { ret = -ENOMEM; folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, dst_vma, dst_addr); @@ -294,13 +308,13 @@ static int mfill_atomic_pte_copy(pmd_t *dst_pmd, /* fallback to copy_from_user outside mmap_lock */ if (unlikely(ret)) { ret = -ENOENT; - *foliop = folio; + state->folio = folio; /* don't free the page */ goto out; } } else { - folio = *foliop; - *foliop = NULL; + folio = state->folio; + state->folio = NULL; } /* @@ -357,10 +371,11 @@ static int mfill_atomic_pte_zeroed_folio(pmd_t *dst_pmd, return ret; } -static int mfill_atomic_pte_zeropage(pmd_t *dst_pmd, - struct vm_area_struct *dst_vma, - unsigned long dst_addr) +static int mfill_atomic_pte_zeropage(struct mfill_state *state) { + struct vm_area_struct *dst_vma = state->vma; + unsigned long dst_addr = state->dst_addr; + pmd_t *dst_pmd = state->pmd; pte_t _dst_pte, *dst_pte; spinlock_t *ptl; int ret; @@ -392,13 +407,14 @@ static int mfill_atomic_pte_zeropage(pmd_t *dst_pmd, } /* Handles UFFDIO_CONTINUE for all shmem VMAs (shared or private). */ -static int mfill_atomic_pte_continue(pmd_t *dst_pmd, - struct vm_area_struct *dst_vma, - unsigned long dst_addr, - uffd_flags_t flags) +static int mfill_atomic_pte_continue(struct mfill_state *state) { - struct inode *inode = file_inode(dst_vma->vm_file); + struct vm_area_struct *dst_vma = state->vma; + unsigned long dst_addr = state->dst_addr; pgoff_t pgoff = linear_page_index(dst_vma, dst_addr); + struct inode *inode = file_inode(dst_vma->vm_file); + uffd_flags_t flags = state->flags; + pmd_t *dst_pmd = state->pmd; struct folio *folio; struct page *page; int ret; @@ -436,15 +452,15 @@ static int mfill_atomic_pte_continue(pmd_t *dst_pmd, } /* Handles UFFDIO_POISON for all non-hugetlb VMAs. */ -static int mfill_atomic_pte_poison(pmd_t *dst_pmd, - struct vm_area_struct *dst_vma, - unsigned long dst_addr, - uffd_flags_t flags) +static int mfill_atomic_pte_poison(struct mfill_state *state) { - int ret; + struct vm_area_struct *dst_vma = state->vma; struct mm_struct *dst_mm = dst_vma->vm_mm; + unsigned long dst_addr = state->dst_addr; + pmd_t *dst_pmd = state->pmd; pte_t _dst_pte, *dst_pte; spinlock_t *ptl; + int ret; _dst_pte = make_pte_marker(PTE_MARKER_POISONED); ret = -EAGAIN; @@ -668,22 +684,20 @@ extern ssize_t mfill_atomic_hugetlb(struct userfaultfd_ctx *ctx, uffd_flags_t flags); #endif /* CONFIG_HUGETLB_PAGE */ -static __always_inline ssize_t mfill_atomic_pte(pmd_t *dst_pmd, - struct vm_area_struct *dst_vma, - unsigned long dst_addr, - unsigned long src_addr, - uffd_flags_t flags, - struct folio **foliop) +static __always_inline ssize_t mfill_atomic_pte(struct mfill_state *state) { + struct vm_area_struct *dst_vma = state->vma; + unsigned long src_addr = state->src_addr; + unsigned long dst_addr = state->dst_addr; + struct folio **foliop = &state->folio; + uffd_flags_t flags = state->flags; + pmd_t *dst_pmd = state->pmd; ssize_t err; - if (uffd_flags_mode_is(flags, MFILL_ATOMIC_CONTINUE)) { - return mfill_atomic_pte_continue(dst_pmd, dst_vma, - dst_addr, flags); - } else if (uffd_flags_mode_is(flags, MFILL_ATOMIC_POISON)) { - return mfill_atomic_pte_poison(dst_pmd, dst_vma, - dst_addr, flags); - } + if (uffd_flags_mode_is(flags, MFILL_ATOMIC_CONTINUE)) + return mfill_atomic_pte_continue(state); + if (uffd_flags_mode_is(flags, MFILL_ATOMIC_POISON)) + return mfill_atomic_pte_poison(state); /* * The normal page fault path for a shmem will invoke the @@ -697,12 +711,9 @@ static __always_inline ssize_t mfill_atomic_pte(pmd_t *dst_pmd, */ if (!(dst_vma->vm_flags & VM_SHARED)) { if (uffd_flags_mode_is(flags, MFILL_ATOMIC_COPY)) - err = mfill_atomic_pte_copy(dst_pmd, dst_vma, - dst_addr, src_addr, - flags, foliop); + err = mfill_atomic_pte_copy(state); else - err = mfill_atomic_pte_zeropage(dst_pmd, - dst_vma, dst_addr); + err = mfill_atomic_pte_zeropage(state); } else { err = shmem_mfill_atomic_pte(dst_pmd, dst_vma, dst_addr, src_addr, @@ -718,13 +729,20 @@ static __always_inline ssize_t mfill_atomic(struct userfaultfd_ctx *ctx, unsigned long len, uffd_flags_t flags) { + struct mfill_state state = (struct mfill_state){ + .ctx = ctx, + .dst_start = dst_start, + .src_start = src_start, + .flags = flags, + + .src_addr = src_start, + .dst_addr = dst_start, + }; struct mm_struct *dst_mm = ctx->mm; struct vm_area_struct *dst_vma; + long copied = 0; ssize_t err; pmd_t *dst_pmd; - unsigned long src_addr, dst_addr; - long copied; - struct folio *folio; /* * Sanitize the command parameters: @@ -736,10 +754,6 @@ static __always_inline ssize_t mfill_atomic(struct userfaultfd_ctx *ctx, VM_WARN_ON_ONCE(src_start + len <= src_start); VM_WARN_ON_ONCE(dst_start + len <= dst_start); - src_addr = src_start; - dst_addr = dst_start; - copied = 0; - folio = NULL; retry: /* * Make sure the vma is not shared, that the dst range is @@ -790,12 +804,14 @@ static __always_inline ssize_t mfill_atomic(struct userfaultfd_ctx *ctx, uffd_flags_mode_is(flags, MFILL_ATOMIC_CONTINUE)) goto out_unlock; - while (src_addr < src_start + len) { - pmd_t dst_pmdval; + state.vma = dst_vma; - VM_WARN_ON_ONCE(dst_addr >= dst_start + len); + while (state.src_addr < src_start + len) { + VM_WARN_ON_ONCE(state.dst_addr >= dst_start + len); + + pmd_t dst_pmdval; - dst_pmd = mm_alloc_pmd(dst_mm, dst_addr); + dst_pmd = mm_alloc_pmd(dst_mm, state.dst_addr); if (unlikely(!dst_pmd)) { err = -ENOMEM; break; @@ -827,34 +843,34 @@ static __always_inline ssize_t mfill_atomic(struct userfaultfd_ctx *ctx, * tables under us; pte_offset_map_lock() will deal with that. */ - err = mfill_atomic_pte(dst_pmd, dst_vma, dst_addr, - src_addr, flags, &folio); + state.pmd = dst_pmd; + err = mfill_atomic_pte(&state); cond_resched(); if (unlikely(err == -ENOENT)) { void *kaddr; up_read(&ctx->map_changing_lock); - uffd_mfill_unlock(dst_vma); - VM_WARN_ON_ONCE(!folio); + uffd_mfill_unlock(state.vma); + VM_WARN_ON_ONCE(!state.folio); - kaddr = kmap_local_folio(folio, 0); + kaddr = kmap_local_folio(state.folio, 0); err = copy_from_user(kaddr, - (const void __user *) src_addr, + (const void __user *)state.src_addr, PAGE_SIZE); kunmap_local(kaddr); if (unlikely(err)) { err = -EFAULT; goto out; } - flush_dcache_folio(folio); + flush_dcache_folio(state.folio); goto retry; } else - VM_WARN_ON_ONCE(folio); + VM_WARN_ON_ONCE(state.folio); if (!err) { - dst_addr += PAGE_SIZE; - src_addr += PAGE_SIZE; + state.dst_addr += PAGE_SIZE; + state.src_addr += PAGE_SIZE; copied += PAGE_SIZE; if (fatal_signal_pending(current)) @@ -866,10 +882,10 @@ static __always_inline ssize_t mfill_atomic(struct userfaultfd_ctx *ctx, out_unlock: up_read(&ctx->map_changing_lock); - uffd_mfill_unlock(dst_vma); + uffd_mfill_unlock(state.vma); out: - if (folio) - folio_put(folio); + if (state.folio) + folio_put(state.folio); VM_WARN_ON_ONCE(copied < 0); VM_WARN_ON_ONCE(err > 0); VM_WARN_ON_ONCE(!copied && !err); -- 2.51.0
