user/sven/glibc.git/manual, branch master

manual: Document that EOPNOTSUPP and ENOTSUP are equal, not distinct (BZ 2363)

2026-02-26T16:43:30Z

The section 2.1 of the glibc manual says that EWOULDBLOCK == EAGAIN, but forgets to mention that ENOTSUP == EOPNOTSUPP. https://sourceware.org/legacy-ml/libc-alpha/2019-08/msg00629.html https://sourceware.org/bugzilla/show_bug.cgi?id=2363 https://bugs.debian.org/337013 Signed-off-by: Nicolas Boulenguez Reviewed-by: Adhemerval Zanella

malloc: alignment might change in future versions

2026-02-26T16:35:05Z

This follows up on a comment by Wilco Dijkstra; see: https://sourceware.org/pipermail/libc-alpha/2026-February/174934.html * NEWS: Mention this. * manual/memory.texi (Malloc Examples): Say that alignment guarantee might change for small allocations. Reviewed-by: Wilco Dijkstra Reviewed-by: Florian Weimer

Say malloc (0) != NULL is now common; resection

2026-02-26T16:35:05Z

* manual/memory.texi (Portable Allocation): New section, split off from Malloc Examples. Say that almost every system follows glibc's example in having successful malloc (0) return non-null; AIX is the only exception nowadays. Document fundamental alignment portability. Have examples match the new text, and use NULL rather than 0. Reviewed-by: Florian Weimer

Document malloc alignment

2026-02-26T16:35:05Z

* manual/memory.texi (Malloc Examples, Changing Block Size) (Allocating Cleared Space): Document the alignment of the returned value. Reviewed-by: Florian Weimer

Document max_align_t

2026-02-26T16:35:05Z

* manual/lang.texi (Important Data Types): Mention max_align_t. Reviewed-by: Florian Weimer

manual: Fix typo in documentation of iconv character set options

2026-02-26T15:44:23Z

Reported-by: Andreas Schwab

aarch64: Lock GCS status at startup

2026-02-17T15:22:47Z

If GCS is enabled (see tunable glibc.cpu.aarch64_gcs), we lock all GCS operations (including status, write on shadow stack, and push to shadow stack) unless OPTIONAL policy is used. Reviewed-by: Adhemerval Zanella

malloc: Remove unused tcache code from unsorted bin scan

2026-02-06T18:20:17Z

Now that fastbins have been removed, there is no need to add chunks to tcache during an unsorted scan. Small blocks can only be added to unsorted as a result of a remainder chunk split off a larger block, so there is no point in checking for additional chunks to place in tcache. The last remainder is checked first, and will be used if it is large enough or an exact fit. The unsorted bin scan becomes simpler as a result. Remove the tcache_unsorted_limit tunable and manual entries. Reviewed-by: Adhemerval Zanella

math: Order signed zeros in f{max,min}mag{f,l,f128}

2026-02-02T17:35:44Z

The functions are documented to behave like fmax/fmin when the arguments have the same absolute value. Checked on x86_64-linux-gnu, aarch64-linux-gnu, i686-linux-gnu, arm-linux-gnueabihf, powerpc64le-linux-gnu, riscv64-linux-gnu-rv64imafdc-lp64d, and loongarch64-linux-gnuf64. Reviewed-by: Wilco Dijkstra

math: Order signed zeros in f{max,min}{f,l,f128}

2026-02-02T17:35:19Z

The C standard (at least from C99 until C23) does not require fmin/fmax to order zeros by their sign, so glibc's previous behavior was entirely standards-conforming. However, the standard does recommend that zeros be ordered in a footnote, saying: "If possible, fmax is sensitive to the sign of zero, for example fmax(−0.0, +0.0) ideally returns +0." As this is indeed possible (and not too complicated), implement it as a quality-of-implementation improvement. It also remove possible deviations between architectures, where for some architectures that has direct mapping instruction (USE_FMA*_BUILTIN) they already do the ordering. Checked on x86_64-linux-gnu, aarch64-linux-gnu, i686-linux-gnu, arm-linux-gnueabihf, powerpc64le-linux-gnu, riscv64-linux-gnu-rv64imafdc-lp64d, and loongarch64-linux-gnuf64. Co-authored-by: James Y Knight Reviewed-by: Wilco Dijkstra