valloc(3) Library Functions Manual valloc(3)

valloc - page-aligned memory allocation

Standard C library (libc, -lc)

#include <stdlib.h>
[[deprecated]] void *valloc(size_t size);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

valloc():



    Since glibc 2.12:

        (_XOPEN_SOURCE >= 500) && !(_POSIX_C_SOURCE >= 200112L)

            || /* glibc >= 2.19: */ _DEFAULT_SOURCE

            || /* glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE

    Before glibc 2.12:

        _BSD_SOURCE || _XOPEN_SOURCE >= 500

valloc() allocates size bytes and returns a pointer to the allocated memory. The memory address will be a multiple of the page size.

It is equivalent to memalign(sysconf(_SC_PAGESIZE),size).

For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
valloc () Thread safety MT-Unsafe init

According to SUSv2, valloc() is declared in <stdlib.h>. glibc declares it in <malloc.h>, and also in <stdlib.h> if suitable feature test macros are defined (see above).

BSD, GNU.

glibc 2.0. 3.0BSD. Documented as obsolete in 4.3BSD, and as legacy in SUSv2.

See memalign(3).

memalign(3)

2025-12-13 Linux man-pages (unreleased)

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