RE: git: 831b1ff7913f - main - UFS/FFS: Migrate to modern uintXX_t from u_intXX_t.

Kirk McKusick <mckusick_at_FreeBSD.org> wrote on
Date: Thu, 27 Jul 2023 22:27:49 UTC :

> The branch main has been updated by mckusick:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=831b1ff7913fb0b317a258a43dce5abefee03a31
> 
> commit 831b1ff7913fb0b317a258a43dce5abefee03a31
> Author: Kirk McKusick <mckusick@FreeBSD.org>
> AuthorDate: 2023-07-27 22:26:01 +0000
> Commit: Kirk McKusick <mckusick@FreeBSD.org>
> CommitDate: 2023-07-27 22:27:36 +0000
> 
> UFS/FFS: Migrate to modern uintXX_t from u_intXX_t.
> 
> As per https://lists.freebsd.org/archives/freebsd-scsi/2023-July/000257.html
> move to the modern uintXX_t. While here also migrate u_char to uint8_t.
> Where other kernel interfaces allow, migrate u_long to uint64_t.

Looks dangerous to me . . .

u_long (a.k.a. unsigned long) on armv7, for example, is
32 bits, not 64. Same for i386, I expect.

For reference, from /usr/include/sys/types.h :

#if __BSD_VISIBLE
typedef unsigned char   u_char;
typedef unsigned short  u_short;
typedef unsigned int    u_int;
typedef unsigned long   u_long;
#ifndef _KERNEL
typedef unsigned short  ushort;         /* Sys V compatibility */
typedef unsigned int    uint;           /* Sys V compatibility */
#endif
#endif

Quoting FreeBSD's man arch:

     ILP32     int, long, void * types machine representations all have 4-byte
               size.

     LP64      int type machine representation uses 4 bytes, while long and
               void * are 8 bytes.

armv7 is ILP32, as, likely, i386 would be as well.

Note that u_int is 32 bits for both ILP32 and LP64, not 64.
But there are a  lot of u_int -> uint64_t replacements in
the update.

> No functional changes intended.

It would appear that it would take a bunch of validation to know if
the size changes actually make no actual difference on the
architectures where some sizes changed.

> MFC-after: 1 week
> Sponsored-by: The FreeBSD Foundation
. . .



===
Mark Millard
marklmi at yahoo.com