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authorTavian Barnes <tavianator@tavianator.com>2023-05-11 13:08:43 -0400
committerTavian Barnes <tavianator@tavianator.com>2023-05-11 13:14:13 -0400
commita7932050f65844fb1f1145fee87c72aadaf4f995 (patch)
tree7284a1d82b06f590df85affc9a3f96d6e13ac0a6 /src
parent7e26443627926bb3bcc88bd790190d5e4e0eda98 (diff)
downloadbfs-a7932050f65844fb1f1145fee87c72aadaf4f995.tar.xz
config: Saturate on overflow in flex_sizeof()
Diffstat (limited to 'src')
-rw-r--r--src/config.h12
1 files changed, 11 insertions, 1 deletions
diff --git a/src/config.h b/src/config.h
index c6dcc1e..b2c58be 100644
--- a/src/config.h
+++ b/src/config.h
@@ -162,7 +162,17 @@ static inline size_t align_ceil(size_t align, size_t size) {
flex_sizeof_impl(alignof(type), sizeof(type), offsetof(type, member), sizeof(((type *)NULL)->member[0]), count)
static inline size_t flex_sizeof_impl(size_t align, size_t min, size_t offset, size_t size, size_t count) {
- size_t ret = align_ceil(align, offset + size * count);
+ size_t ret = size * count;
+ size_t overflow = ret / size != count;
+
+ ret += offset;
+ overflow |= ret < offset;
+
+ size_t mask = align - 1;
+ ret += mask;
+ overflow |= ret < mask;
+ ret &= ~mask;
+ ret |= -overflow;
// Make sure flex_sizeof(type, member, 0) >= sizeof(type), even if the
// type has more padding than necessary for alignment