Here's how it looks:
$ MANWIDTH=72 diffman-git f19bb100f31e
--- f19bb100f31e^:man/man3/aligned_alloc.3
+++ f19bb100f31e:man/man3/aligned_alloc.3
@@ -52,6 +52,41 @@ STANDARDS
HISTORY
glibc 2.16. C11, POSIX.1‐2024.
+ C11
+ In C11, the specification of this function had several issues.
+
+ • size had to be a multiple of alignment. Otherwise, the behav‐
+ ior was undefined.
+
+ • If alignment was not a power of two, the behavior was unde‐
+ fined.
+
+ DR460 reported both cases of UB as unnecessarily dangerous, and
+ fixed them with a Technical Corrigendum that transformed them into
+ errors.
+
+ N2072 reported that the requirement that size is a multiple of
+ alignment is superfluous, and removed it with a Technical Corri‐
+ gendum.
+
+ C17 incorporates both technical corrigenda. The API has been sta‐
+ ble since C17.
+
+ glibc originally implemented it as silently aligning as
+ stdc_bit_ceil(alignment) instead of alignment. Since glibc 2.38,
+ it implements the C17 specification.
+
+ Some implementations, such as FreeBSD/jemalloc, implement the C17
+ specification, even though their documentation claims the C11
+ specification.
+
+ Some implementations, such as OpenBSD, implement C11 amended with
+ DR460, even though their documentation claims having undefined be‐
+ havior.
+
+ No known implementations have exploited the undefined behavior in
+ a more dangerous way. This function should be safe to use.
+
NOTES
On many systems there are alignment restrictions, for example, on
buffers used for direct block device I/O. POSIX specifies the-- <https://www.alejandro-colomar.es>
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