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    SubjectRe: modutils-2.3.15 'insmod'
    Quoth Richard B. Johnson:
    > modutils-2.3.15, and probably later, has a bug that can prevent
    > modules from being loaded from initrd, this results in not
    > being able to mount a root file-system. The bug assumes that
    > malloc() will return a valid pointer when given an allocation
    > size of zero.

    This isn't a bug. The standard allow returning a non-null pointer
    for malloc(0).

    > When there are no modules loaded, insmod scans for modules
    > and allocates data using its xmalloc() based upon the number
    > of modules found. If the number was 0, it attempts to allocate
    > 0 bytes (0 times the size of a structure). If malloc() returns
    > NULL (and it can, probably should), xmalloc() will write an
    > "out of memory" diagnostic and call exit().
    > The most recent `man` pages that RH 9.0 distributes states that
    > malloc() can return either NULL of a pointer that is valid for
    > free(). This, of course, depends upon the 'C' runtime library's
    > malloc() implementation.

    Perhaps, but IIRC, the rationale in the GNU C library was that
    existing programs assume malloc(0) != 0, which allows you to call
    realloc on the pointer. Returning NULL only makes sense if the
    malloc() call fails.

    > It is likely that malloc(0) returning a valid pointer is a bug
    > that has prevented this problem from being observed. Such a
    > bug in malloc() is probably necessary to keep legacy software

    Not a bug. Bad design perhaps, but not a bug.

    > running, but new software shouldn't use such atrocious side-effects.
    > An allocation of zero needs to be discovered and fixed early
    > in code design.

    If you sit down at a poker game and don't see a sucker, get up. You're
    the sucker.
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