diff options
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 416 |
1 files changed, 175 insertions, 241 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 227c9f536b94..65374ee91ecd 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -13,189 +13,69 @@ #include <net/checksum.h> #include <linux/scatterlist.h> #include <linux/instrumented.h> +#include <linux/iov_iter.h> -/* covers ubuf and kbuf alike */ -#define iterate_buf(i, n, base, len, off, __p, STEP) { \ - size_t __maybe_unused off = 0; \ - len = n; \ - base = __p + i->iov_offset; \ - len -= (STEP); \ - i->iov_offset += len; \ - n = len; \ -} - -/* covers iovec and kvec alike */ -#define iterate_iovec(i, n, base, len, off, __p, STEP) { \ - size_t off = 0; \ - size_t skip = i->iov_offset; \ - do { \ - len = min(n, __p->iov_len - skip); \ - if (likely(len)) { \ - base = __p->iov_base + skip; \ - len -= (STEP); \ - off += len; \ - skip += len; \ - n -= len; \ - if (skip < __p->iov_len) \ - break; \ - } \ - __p++; \ - skip = 0; \ - } while (n); \ - i->iov_offset = skip; \ - n = off; \ -} - -#define iterate_bvec(i, n, base, len, off, p, STEP) { \ - size_t off = 0; \ - unsigned skip = i->iov_offset; \ - while (n) { \ - unsigned offset = p->bv_offset + skip; \ - unsigned left; \ - void *kaddr = kmap_local_page(p->bv_page + \ - offset / PAGE_SIZE); \ - base = kaddr + offset % PAGE_SIZE; \ - len = min(min(n, (size_t)(p->bv_len - skip)), \ - (size_t)(PAGE_SIZE - offset % PAGE_SIZE)); \ - left = (STEP); \ - kunmap_local(kaddr); \ - len -= left; \ - off += len; \ - skip += len; \ - if (skip == p->bv_len) { \ - skip = 0; \ - p++; \ - } \ - n -= len; \ - if (left) \ - break; \ - } \ - i->iov_offset = skip; \ - n = off; \ -} - -#define iterate_xarray(i, n, base, len, __off, STEP) { \ - __label__ __out; \ - size_t __off = 0; \ - struct folio *folio; \ - loff_t start = i->xarray_start + i->iov_offset; \ - pgoff_t index = start / PAGE_SIZE; \ - XA_STATE(xas, i->xarray, index); \ - \ - len = PAGE_SIZE - offset_in_page(start); \ - rcu_read_lock(); \ - xas_for_each(&xas, folio, ULONG_MAX) { \ - unsigned left; \ - size_t offset; \ - if (xas_retry(&xas, folio)) \ - continue; \ - if (WARN_ON(xa_is_value(folio))) \ - break; \ - if (WARN_ON(folio_test_hugetlb(folio))) \ - break; \ - offset = offset_in_folio(folio, start + __off); \ - while (offset < folio_size(folio)) { \ - base = kmap_local_folio(folio, offset); \ - len = min(n, len); \ - left = (STEP); \ - kunmap_local(base); \ - len -= left; \ - __off += len; \ - n -= len; \ - if (left || n == 0) \ - goto __out; \ - offset += len; \ - len = PAGE_SIZE; \ - } \ - } \ -__out: \ - rcu_read_unlock(); \ - i->iov_offset += __off; \ - n = __off; \ -} - -#define __iterate_and_advance(i, n, base, len, off, I, K) { \ - if (unlikely(i->count < n)) \ - n = i->count; \ - if (likely(n)) { \ - if (likely(iter_is_ubuf(i))) { \ - void __user *base; \ - size_t len; \ - iterate_buf(i, n, base, len, off, \ - i->ubuf, (I)) \ - } else if (likely(iter_is_iovec(i))) { \ - const struct iovec *iov = iter_iov(i); \ - void __user *base; \ - size_t len; \ - iterate_iovec(i, n, base, len, off, \ - iov, (I)) \ - i->nr_segs -= iov - iter_iov(i); \ - i->__iov = iov; \ - } else if (iov_iter_is_bvec(i)) { \ - const struct bio_vec *bvec = i->bvec; \ - void *base; \ - size_t len; \ - iterate_bvec(i, n, base, len, off, \ - bvec, (K)) \ - i->nr_segs -= bvec - i->bvec; \ - i->bvec = bvec; \ - } else if (iov_iter_is_kvec(i)) { \ - const struct kvec *kvec = i->kvec; \ - void *base; \ - size_t len; \ - iterate_iovec(i, n, base, len, off, \ - kvec, (K)) \ - i->nr_segs -= kvec - i->kvec; \ - i->kvec = kvec; \ - } else if (iov_iter_is_xarray(i)) { \ - void *base; \ - size_t len; \ - iterate_xarray(i, n, base, len, off, \ - (K)) \ - } \ - i->count -= n; \ - } \ -} -#define iterate_and_advance(i, n, base, len, off, I, K) \ - __iterate_and_advance(i, n, base, len, off, I, ((void)(K),0)) - -static int copyout(void __user *to, const void *from, size_t n) +static __always_inline +size_t copy_to_user_iter(void __user *iter_to, size_t progress, + size_t len, void *from, void *priv2) { if (should_fail_usercopy()) - return n; - if (access_ok(to, n)) { - instrument_copy_to_user(to, from, n); - n = raw_copy_to_user(to, from, n); + return len; + if (access_ok(iter_to, len)) { + from += progress; + instrument_copy_to_user(iter_to, from, len); + len = raw_copy_to_user(iter_to, from, len); } - return n; + return len; } -static int copyout_nofault(void __user *to, const void *from, size_t n) +static __always_inline +size_t copy_to_user_iter_nofault(void __user *iter_to, size_t progress, + size_t len, void *from, void *priv2) { - long res; + ssize_t res; if (should_fail_usercopy()) - return n; - - res = copy_to_user_nofault(to, from, n); + return len; - return res < 0 ? n : res; + from += progress; + res = copy_to_user_nofault(iter_to, from, len); + return res < 0 ? len : res; } -static int copyin(void *to, const void __user *from, size_t n) +static __always_inline +size_t copy_from_user_iter(void __user *iter_from, size_t progress, + size_t len, void *to, void *priv2) { - size_t res = n; + size_t res = len; if (should_fail_usercopy()) - return n; - if (access_ok(from, n)) { - instrument_copy_from_user_before(to, from, n); - res = raw_copy_from_user(to, from, n); - instrument_copy_from_user_after(to, from, n, res); + return len; + if (access_ok(iter_from, len)) { + to += progress; + instrument_copy_from_user_before(to, iter_from, len); + res = raw_copy_from_user(to, iter_from, len); + instrument_copy_from_user_after(to, iter_from, len, res); } return res; } +static __always_inline +size_t memcpy_to_iter(void *iter_to, size_t progress, + size_t len, void *from, void *priv2) +{ + memcpy(iter_to, from + progress, len); + return 0; +} + +static __always_inline +size_t memcpy_from_iter(void *iter_from, size_t progress, + size_t len, void *to, void *priv2) +{ + memcpy(to + progress, iter_from, len); + return 0; +} + /* * fault_in_iov_iter_readable - fault in iov iterator for reading * @i: iterator @@ -312,23 +192,29 @@ size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) return 0; if (user_backed_iter(i)) might_fault(); - iterate_and_advance(i, bytes, base, len, off, - copyout(base, addr + off, len), - memcpy(base, addr + off, len) - ) - - return bytes; + return iterate_and_advance(i, bytes, (void *)addr, + copy_to_user_iter, memcpy_to_iter); } EXPORT_SYMBOL(_copy_to_iter); #ifdef CONFIG_ARCH_HAS_COPY_MC -static int copyout_mc(void __user *to, const void *from, size_t n) -{ - if (access_ok(to, n)) { - instrument_copy_to_user(to, from, n); - n = copy_mc_to_user((__force void *) to, from, n); +static __always_inline +size_t copy_to_user_iter_mc(void __user *iter_to, size_t progress, + size_t len, void *from, void *priv2) +{ + if (access_ok(iter_to, len)) { + from += progress; + instrument_copy_to_user(iter_to, from, len); + len = copy_mc_to_user(iter_to, from, len); } - return n; + return len; +} + +static __always_inline +size_t memcpy_to_iter_mc(void *iter_to, size_t progress, + size_t len, void *from, void *priv2) +{ + return copy_mc_to_kernel(iter_to, from + progress, len); } /** @@ -361,22 +247,20 @@ size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i) return 0; if (user_backed_iter(i)) might_fault(); - __iterate_and_advance(i, bytes, base, len, off, - copyout_mc(base, addr + off, len), - copy_mc_to_kernel(base, addr + off, len) - ) - - return bytes; + return iterate_and_advance(i, bytes, (void *)addr, + copy_to_user_iter_mc, memcpy_to_iter_mc); } EXPORT_SYMBOL_GPL(_copy_mc_to_iter); #endif /* CONFIG_ARCH_HAS_COPY_MC */ -static void *memcpy_from_iter(struct iov_iter *i, void *to, const void *from, - size_t size) +static size_t memcpy_from_iter_mc(void *iter_from, size_t progress, + size_t len, void *to, void *priv2) { - if (iov_iter_is_copy_mc(i)) - return (void *)copy_mc_to_kernel(to, from, size); - return memcpy(to, from, size); + struct iov_iter *iter = priv2; + + if (iov_iter_is_copy_mc(iter)) + return copy_mc_to_kernel(to + progress, iter_from, len); + return memcpy_from_iter(iter_from, progress, len, to, priv2); } size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) @@ -386,30 +270,46 @@ size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) if (user_backed_iter(i)) might_fault(); - iterate_and_advance(i, bytes, base, len, off, - copyin(addr + off, base, len), - memcpy_from_iter(i, addr + off, base, len) - ) - - return bytes; + return iterate_and_advance2(i, bytes, addr, i, + copy_from_user_iter, + memcpy_from_iter_mc); } EXPORT_SYMBOL(_copy_from_iter); +static __always_inline +size_t copy_from_user_iter_nocache(void __user *iter_from, size_t progress, + size_t len, void *to, void *priv2) +{ + return __copy_from_user_inatomic_nocache(to + progress, iter_from, len); +} + size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) { if (WARN_ON_ONCE(!i->data_source)) return 0; - iterate_and_advance(i, bytes, base, len, off, - __copy_from_user_inatomic_nocache(addr + off, base, len), - memcpy(addr + off, base, len) - ) - - return bytes; + return iterate_and_advance(i, bytes, addr, + copy_from_user_iter_nocache, + memcpy_from_iter); } EXPORT_SYMBOL(_copy_from_iter_nocache); #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE +static __always_inline +size_t copy_from_user_iter_flushcache(void __user *iter_from, size_t progress, + size_t len, void *to, void *priv2) +{ + return __copy_from_user_flushcache(to + progress, iter_from, len); +} + +static __always_inline +size_t memcpy_from_iter_flushcache(void *iter_from, size_t progress, + size_t len, void *to, void *priv2) +{ + memcpy_flushcache(to + progress, iter_from, len); + return 0; +} + /** * _copy_from_iter_flushcache - write destination through cpu cache * @addr: destination kernel address @@ -431,12 +331,9 @@ size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) if (WARN_ON_ONCE(!i->data_source)) return 0; - iterate_and_advance(i, bytes, base, len, off, - __copy_from_user_flushcache(addr + off, base, len), - memcpy_flushcache(addr + off, base, len) - ) - - return bytes; + return iterate_and_advance(i, bytes, addr, + copy_from_user_iter_flushcache, + memcpy_from_iter_flushcache); } EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); #endif @@ -508,10 +405,9 @@ size_t copy_page_to_iter_nofault(struct page *page, unsigned offset, size_t byte void *kaddr = kmap_local_page(page); size_t n = min(bytes, (size_t)PAGE_SIZE - offset); - iterate_and_advance(i, n, base, len, off, - copyout_nofault(base, kaddr + offset + off, len), - memcpy(base, kaddr + offset + off, len) - ) + n = iterate_and_advance(i, bytes, kaddr, + copy_to_user_iter_nofault, + memcpy_to_iter); kunmap_local(kaddr); res += n; bytes -= n; @@ -554,14 +450,25 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, } EXPORT_SYMBOL(copy_page_from_iter); -size_t iov_iter_zero(size_t bytes, struct iov_iter *i) +static __always_inline +size_t zero_to_user_iter(void __user *iter_to, size_t progress, + size_t len, void *priv, void *priv2) { - iterate_and_advance(i, bytes, base, len, count, - clear_user(base, len), - memset(base, 0, len) - ) + return clear_user(iter_to, len); +} - return bytes; +static __always_inline +size_t zero_to_iter(void *iter_to, size_t progress, + size_t len, void *priv, void *priv2) +{ + memset(iter_to, 0, len); + return 0; +} + +size_t iov_iter_zero(size_t bytes, struct iov_iter *i) +{ + return iterate_and_advance(i, bytes, NULL, + zero_to_user_iter, zero_to_iter); } EXPORT_SYMBOL(iov_iter_zero); @@ -586,10 +493,9 @@ size_t copy_page_from_iter_atomic(struct page *page, size_t offset, } p = kmap_atomic(page) + offset; - iterate_and_advance(i, n, base, len, off, - copyin(p + off, base, len), - memcpy_from_iter(i, p + off, base, len) - ) + n = iterate_and_advance2(i, n, p, i, + copy_from_user_iter, + memcpy_from_iter_mc); kunmap_atomic(p); copied += n; offset += n; @@ -1180,32 +1086,64 @@ ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, } EXPORT_SYMBOL(iov_iter_get_pages_alloc2); +static __always_inline +size_t copy_from_user_iter_csum(void __user *iter_from, size_t progress, + size_t len, void *to, void *priv2) +{ + __wsum next, *csum = priv2; + + next = csum_and_copy_from_user(iter_from, to + progress, len); + *csum = csum_block_add(*csum, next, progress); + return next ? 0 : len; +} + +static __always_inline +size_t memcpy_from_iter_csum(void *iter_from, size_t progress, + size_t len, void *to, void *priv2) +{ + __wsum *csum = priv2; + + *csum = csum_and_memcpy(to + progress, iter_from, len, *csum, progress); + return 0; +} + size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i) { - __wsum sum, next; - sum = *csum; if (WARN_ON_ONCE(!i->data_source)) return 0; - - iterate_and_advance(i, bytes, base, len, off, ({ - next = csum_and_copy_from_user(base, addr + off, len); - sum = csum_block_add(sum, next, off); - next ? 0 : len; - }), ({ - sum = csum_and_memcpy(addr + off, base, len, sum, off); - }) - ) - *csum = sum; - return bytes; + return iterate_and_advance2(i, bytes, addr, csum, + copy_from_user_iter_csum, + memcpy_from_iter_csum); } EXPORT_SYMBOL(csum_and_copy_from_iter); +static __always_inline +size_t copy_to_user_iter_csum(void __user *iter_to, size_t progress, + size_t len, void *from, void *priv2) +{ + __wsum next, *csum = priv2; + + next = csum_and_copy_to_user(from + progress, iter_to, len); + *csum = csum_block_add(*csum, next, progress); + return next ? 0 : len; +} + +static __always_inline +size_t memcpy_to_iter_csum(void *iter_to, size_t progress, + size_t len, void *from, void *priv2) +{ + __wsum *csum = priv2; + + *csum = csum_and_memcpy(iter_to, from + progress, len, *csum, progress); + return 0; +} + size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate, struct iov_iter *i) { struct csum_state *csstate = _csstate; - __wsum sum, next; + __wsum sum; if (WARN_ON_ONCE(i->data_source)) return 0; @@ -1219,14 +1157,10 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate, } sum = csum_shift(csstate->csum, csstate->off); - iterate_and_advance(i, bytes, base, len, off, ({ - next = csum_and_copy_to_user(addr + off, base, len); - sum = csum_block_add(sum, next, off); - next ? 0 : len; - }), ({ - sum = csum_and_memcpy(base, addr + off, len, sum, off); - }) - ) + + bytes = iterate_and_advance2(i, bytes, (void *)addr, &sum, + copy_to_user_iter_csum, + memcpy_to_iter_csum); csstate->csum = csum_shift(sum, csstate->off); csstate->off += bytes; return bytes; |