From a67b902c94a2f33275a3947a8bcdab03f64ae75e Mon Sep 17 00:00:00 2001 From: Toon Claes Date: Wed, 10 Dec 2025 14:13:01 +0100 Subject: [PATCH] git-compat-util: introduce MEMZERO_ARRAY() macro Introduce a new macro MEMZERO_ARRAY() that zeroes the memory allocated by ALLOC_ARRAY() and friends. And add coccinelle rule to enforce the use of this macro. Signed-off-by: Toon Claes Signed-off-by: Junio C Hamano --- builtin/last-modified.c | 2 +- compat/simple-ipc/ipc-win32.c | 2 +- contrib/coccinelle/array.cocci | 20 ++++++++++++++++++++ diff-delta.c | 2 +- ewah/bitmap.c | 7 +++---- git-compat-util.h | 1 + hashmap.c | 2 +- pack-revindex.c | 2 +- 8 files changed, 29 insertions(+), 9 deletions(-) diff --git a/builtin/last-modified.c b/builtin/last-modified.c index cc5fd2e795..ac5387e861 100644 --- a/builtin/last-modified.c +++ b/builtin/last-modified.c @@ -327,7 +327,7 @@ static void process_parent(struct last_modified *lm, if (!(parent->object.flags & PARENT1)) active_paths_free(lm, parent); - memset(lm->scratch->words, 0x0, lm->scratch->word_alloc * sizeof(eword_t)); + MEMZERO_ARRAY(lm->scratch->words, lm->scratch->word_alloc); diff_queue_clear(&diff_queued_diff); } diff --git a/compat/simple-ipc/ipc-win32.c b/compat/simple-ipc/ipc-win32.c index a8fc812adf..4a3e7df9c7 100644 --- a/compat/simple-ipc/ipc-win32.c +++ b/compat/simple-ipc/ipc-win32.c @@ -686,7 +686,7 @@ static LPSECURITY_ATTRIBUTES get_sa(struct my_sa_data *d) goto fail; } - memset(ea, 0, NR_EA * sizeof(EXPLICIT_ACCESS)); + MEMZERO_ARRAY(ea, NR_EA); ea[0].grfAccessPermissions = GENERIC_READ | GENERIC_WRITE; ea[0].grfAccessMode = SET_ACCESS; diff --git a/contrib/coccinelle/array.cocci b/contrib/coccinelle/array.cocci index 27a3b479c9..d306f6a21e 100644 --- a/contrib/coccinelle/array.cocci +++ b/contrib/coccinelle/array.cocci @@ -101,3 +101,23 @@ expression dst, src, n; -ALLOC_ARRAY(dst, n); -COPY_ARRAY(dst, src, n); +DUP_ARRAY(dst, src, n); + +@@ +type T; +T *ptr; +expression n; +@@ +- memset(ptr, \( 0x0 \| 0 \), n * \( sizeof(T) +- \| sizeof(*ptr) +- \) ) ++ MEMZERO_ARRAY(ptr, n) + +@@ +type T; +T[] ptr; +expression n; +@@ +- memset(ptr, \( 0x0 \| 0 \), n * \( sizeof(T) +- \| sizeof(*ptr) +- \) ) ++ MEMZERO_ARRAY(ptr, n) diff --git a/diff-delta.c b/diff-delta.c index 71d37368d6..43c339f010 100644 --- a/diff-delta.c +++ b/diff-delta.c @@ -171,7 +171,7 @@ struct delta_index * create_delta_index(const void *buf, unsigned long bufsize) mem = hash + hsize; entry = mem; - memset(hash, 0, hsize * sizeof(*hash)); + MEMZERO_ARRAY(hash, hsize); /* allocate an array to count hash entries */ hash_count = calloc(hsize, sizeof(*hash_count)); diff --git a/ewah/bitmap.c b/ewah/bitmap.c index 55928dada8..bf878bf876 100644 --- a/ewah/bitmap.c +++ b/ewah/bitmap.c @@ -46,8 +46,7 @@ static void bitmap_grow(struct bitmap *self, size_t word_alloc) { size_t old_size = self->word_alloc; ALLOC_GROW(self->words, word_alloc, self->word_alloc); - memset(self->words + old_size, 0x0, - (self->word_alloc - old_size) * sizeof(eword_t)); + MEMZERO_ARRAY(self->words + old_size, (self->word_alloc - old_size)); } void bitmap_set(struct bitmap *self, size_t pos) @@ -192,8 +191,8 @@ void bitmap_or_ewah(struct bitmap *self, struct ewah_bitmap *other) if (self->word_alloc < other_final) { self->word_alloc = other_final; REALLOC_ARRAY(self->words, self->word_alloc); - memset(self->words + original_size, 0x0, - (self->word_alloc - original_size) * sizeof(eword_t)); + MEMZERO_ARRAY(self->words + original_size, + (self->word_alloc - original_size)); } ewah_iterator_init(&it, other); diff --git a/git-compat-util.h b/git-compat-util.h index 398e0fac4f..2b8192fd2e 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -726,6 +726,7 @@ static inline uint64_t u64_add(uint64_t a, uint64_t b) #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc))) #define CALLOC_ARRAY(x, alloc) (x) = xcalloc((alloc), sizeof(*(x))) #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc))) +#define MEMZERO_ARRAY(x, alloc) memset((x), 0x0, st_mult(sizeof(*(x)), (alloc))) #define COPY_ARRAY(dst, src, n) copy_array((dst), (src), (n), sizeof(*(dst)) + \ BARF_UNLESS_COPYABLE((dst), (src))) diff --git a/hashmap.c b/hashmap.c index a711377853..3b5d6f14bc 100644 --- a/hashmap.c +++ b/hashmap.c @@ -194,7 +194,7 @@ void hashmap_partial_clear_(struct hashmap *map, ssize_t entry_offset) return; if (entry_offset >= 0) /* called by hashmap_clear_entries */ free_individual_entries(map, entry_offset); - memset(map->table, 0, map->tablesize * sizeof(struct hashmap_entry *)); + MEMZERO_ARRAY(map->table, map->tablesize); map->shrink_at = 0; map->private_size = 0; } diff --git a/pack-revindex.c b/pack-revindex.c index d0791cc493..8598b941c8 100644 --- a/pack-revindex.c +++ b/pack-revindex.c @@ -75,7 +75,7 @@ static void sort_revindex(struct revindex_entry *entries, unsigned n, off_t max) for (bits = 0; max >> bits; bits += DIGIT_SIZE) { unsigned i; - memset(pos, 0, BUCKETS * sizeof(*pos)); + MEMZERO_ARRAY(pos, BUCKETS); /* * We want pos[i] to store the index of the last element that