[PATCH 4/8] core: use rest_of_page() macro where appropriate
From: Yury Norov <hidden>
Date: 2026-03-04 01:27:47
Also in:
dm-devel, dri-devel, intel-gfx, kvm, linux-block, linux-crypto, linux-ext4, linux-f2fs-devel, linux-fsdevel, linux-mm, linux-nfs, linux-perf-users, linux-riscv, linux-s390, linux-sound, linux-spi, linux-xfs, lkml, netdev, v9fs, virtualization
Subsystem:
bitmap api, crypto api, filesystems [iomap], library code, memory management - core, performance events subsystem, the rest, userspace copyin/copyout (uiovec) · Maintainers:
Yury Norov, Herbert Xu, "David S. Miller", Christian Brauner, Andrew Morton, David Hildenbrand, Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds, Alexander Viro
Switch core and library code to using the macro. No functional changes intended. Signed-off-by: Yury Norov <redacted> --- include/crypto/scatterwalk.h | 2 +- include/linux/highmem.h | 24 ++++++++++-------------- include/linux/iomap.h | 2 +- include/linux/iov_iter.h | 3 +-- kernel/events/ring_buffer.c | 2 +- lib/bitmap-str.c | 2 +- lib/iov_iter.c | 5 ++--- 7 files changed, 17 insertions(+), 23 deletions(-)
diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h
index 624fab589c2c..c671d5383c12 100644
--- a/include/crypto/scatterwalk.h
+++ b/include/crypto/scatterwalk.h@@ -73,7 +73,7 @@ static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk, * page due to the data not being aligned to the algorithm's alignmask. */ if (IS_ENABLED(CONFIG_HIGHMEM)) - limit = PAGE_SIZE - offset_in_page(walk->offset); + limit = rest_of_page(walk->offset); else limit = PAGE_SIZE;
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index af03db851a1d..05528ba886fb 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h@@ -507,12 +507,10 @@ static inline void memcpy_folio(struct folio *dst_folio, size_t dst_off, const char *src = kmap_local_folio(src_folio, src_off); size_t chunk = len; - if (folio_test_highmem(dst_folio) && - chunk > PAGE_SIZE - offset_in_page(dst_off)) - chunk = PAGE_SIZE - offset_in_page(dst_off); - if (folio_test_highmem(src_folio) && - chunk > PAGE_SIZE - offset_in_page(src_off)) - chunk = PAGE_SIZE - offset_in_page(src_off); + if (folio_test_highmem(dst_folio) && chunk > rest_of_page(dst_off)) + chunk = rest_of_page(dst_off); + if (folio_test_highmem(src_folio) && chunk > rest_of_page(src_off)) + chunk = rest_of_page(src_off); memcpy(dst, src, chunk); kunmap_local(src); kunmap_local(dst);
@@ -580,9 +578,8 @@ static inline void memcpy_from_folio(char *to, struct folio *folio, const char *from = kmap_local_folio(folio, offset); size_t chunk = len; - if (folio_test_partial_kmap(folio) && - chunk > PAGE_SIZE - offset_in_page(offset)) - chunk = PAGE_SIZE - offset_in_page(offset); + if (folio_test_partial_kmap(folio) && chunk > rest_of_page(offset)) + chunk = rest_of_page(offset); memcpy(to, from, chunk); kunmap_local(from);
@@ -608,9 +605,8 @@ static inline void memcpy_to_folio(struct folio *folio, size_t offset, char *to = kmap_local_folio(folio, offset); size_t chunk = len; - if (folio_test_partial_kmap(folio) && - chunk > PAGE_SIZE - offset_in_page(offset)) - chunk = PAGE_SIZE - offset_in_page(offset); + if (folio_test_partial_kmap(folio) && chunk > rest_of_page(offset)) + chunk = rest_of_page(offset); memcpy(to, from, chunk); kunmap_local(to);
@@ -642,7 +638,7 @@ static inline __must_check void *folio_zero_tail(struct folio *folio, size_t len = folio_size(folio) - offset; if (folio_test_partial_kmap(folio)) { - size_t max = PAGE_SIZE - offset_in_page(offset); + size_t max = rest_of_page(offset); while (len > max) { memset(kaddr, 0, max);
@@ -680,7 +676,7 @@ static inline void folio_fill_tail(struct folio *folio, size_t offset, VM_BUG_ON(offset + len > folio_size(folio)); if (folio_test_partial_kmap(folio)) { - size_t max = PAGE_SIZE - offset_in_page(offset); + size_t max = rest_of_page(offset); while (len > max) { memcpy(to, from, max);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 99b7209dabd7..6ae549192adb 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h@@ -142,7 +142,7 @@ static inline void *iomap_inline_data(const struct iomap *iomap, loff_t pos) */ static inline bool iomap_inline_data_valid(const struct iomap *iomap) { - return iomap->length <= PAGE_SIZE - offset_in_page(iomap->inline_data); + return iomap->length <= rest_of_page(iomap->inline_data); } /*
diff --git a/include/linux/iov_iter.h b/include/linux/iov_iter.h
index f9a17fbbd398..13a9ee653ef8 100644
--- a/include/linux/iov_iter.h
+++ b/include/linux/iov_iter.h@@ -227,8 +227,7 @@ size_t iterate_xarray(struct iov_iter *iter, size_t len, void *priv, void *priv2 while (flen) { void *base = kmap_local_folio(folio, offset); - part = min_t(size_t, flen, - PAGE_SIZE - offset_in_page(offset)); + part = min_t(size_t, flen, rest_of_page(offset)); remain = step(base, progress, part, priv, priv2); kunmap_local(base);
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 3e7de2661417..1db2868b90c9 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c@@ -590,7 +590,7 @@ long perf_output_copy_aux(struct perf_output_handle *aux_handle, to &= (rb->aux_nr_pages << PAGE_SHIFT) - 1; do { - tocopy = PAGE_SIZE - offset_in_page(from); + tocopy = rest_of_page(from); if (to > from) tocopy = min(tocopy, to - from); if (!tocopy)
diff --git a/lib/bitmap-str.c b/lib/bitmap-str.c
index be745209507a..a357342d5d6c 100644
--- a/lib/bitmap-str.c
+++ b/lib/bitmap-str.c@@ -58,7 +58,7 @@ EXPORT_SYMBOL(bitmap_parse_user); int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, int nmaskbits) { - ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); + ptrdiff_t len = rest_of_page(buf); return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 0a63c7fba313..c7e812349ca2 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c@@ -483,9 +483,8 @@ size_t copy_folio_from_iter_atomic(struct folio *folio, size_t offset, char *to = kmap_local_folio(folio, offset); n = bytes - copied; - if (folio_test_partial_kmap(folio) && - n > PAGE_SIZE - offset_in_page(offset)) - n = PAGE_SIZE - offset_in_page(offset); + if (folio_test_partial_kmap(folio) && n > rest_of_page(offset)) + n = rest_of_page(offset); pagefault_disable(); n = __copy_from_iter(to, n, i);
--
2.43.0