zfs-2.1.4-78_g090bda59e (branch zfs-2.1.5-staging) kernel 5.18 dkms build error on RHEL 8.6 (Rocky Linux)

[edefaria]

System information

Type	Version/Name
Distribution Name	RHEL (Rocky Linux)
Distribution Version	8.6
Kernel Version	5.18.0-1.el8.elrepo.x86_64
Architecture	x86_64
OpenZFS Version	zfs-2.1.4-78_g090bda59e

Describe the problem you're observing

Building zfs with elrepo kernel-ml 5.18 failed on dkms build, no issue building kernel-ml 5.17.

Describe how to reproduce the problem

Install RHEL 8.6, download elrepo kernel-ml and clone/build zfs-2.1.5-staging with default behaviour:
$ ./autogen.sh
$ ./configure
$ make rpm
dkms failed to build on both kernel-ml 5.18.0-1.el8.elrepo.x86_64 and 5.18.1-1.el8.elrepo.x86_64.

Include any warning/errors/backtraces from the system logs

https://gist.github.com/edefaria/f4d4f960ea277b1bdb57bfdf2dcd3a87

[tonyhutter]

For quick reference, here's one of the errors:

    CC [M]  /var/lib/dkms/zfs/2.1.4/build/module/zfs/dsl_prop.o
In file included from ./include/linux/string.h:253,
                 from ./include/linux/bitmap.h:11,
                 from ./include/linux/cpumask.h:12,
                 from ./arch/x86/include/asm/cpumask.h:5,
                 from ./arch/x86/include/asm/msr.h:11,
                 from ./arch/x86/include/asm/processor.h:22,
                 from ./arch/x86/include/asm/timex.h:5,
                 from ./include/linux/timex.h:67,
                 from ./include/linux/time32.h:13,
                 from ./include/linux/time.h:60,
                 from ./include/linux/stat.h:19,
                 from ./include/linux/module.h:13,
                 from /var/lib/dkms/zfs/2.1.4/build/include/os/linux/spl/sys/atomic.h:27,
                 from /var/lib/dkms/zfs/2.1.4/build/include/sys/zfs_context.h:46,
                 from /var/lib/dkms/zfs/2.1.4/build/module/zfs/dsl_bookmark.c:22:
In function 'fortify_memset_chk',
    inlined from 'dsl_bookmark_set_phys' at /var/lib/dkms/zfs/2.1.4/build/module/zfs/dsl_bookmark.c:384:3:
./include/linux/fortify-string.h:242:4: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror]
    __write_overflow_field(p_size_field, size);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  CC [M]  /var/lib/dkms/zfs/2.1.4/build/module/zfs/dsl_scan.o
  CC [M]  /var/lib/dkms/zfs/2.1.4/build/module/zfs/dsl_synctask.o
  CC [M]  /var/lib/dkms/zfs/2.1.4/build/module/zfs/dsl_userhold.o

I'm guessing you're hitting this since you're building with fortify source? Here's the code in question:

       } else {
              bzero(&zbm->zbm_flags,
                  sizeof (zfs_bookmark_phys_t) -
                  offsetof(zfs_bookmark_phys_t, zbm_flags));
       }
...


/*
 * On disk zap object.
 */
typedef struct zfs_bookmark_phys {
       uint64_t zbm_guid;          /* guid of bookmarked dataset */
       uint64_t zbm_creation_txg;  /* birth transaction group */
       uint64_t zbm_creation_time; /* bookmark creation time */

       /* fields used for redacted send / recv */
       uint64_t zbm_redaction_obj; /* redaction list object */
       uint64_t zbm_flags;         /* ZBM_FLAG_* */

       /* fields used for bookmark written size */
       uint64_t zbm_referenced_bytes_refd;
       uint64_t zbm_compressed_bytes_refd;
       uint64_t zbm_uncompressed_bytes_refd;
       uint64_t zbm_referenced_freed_before_next_snap;
       uint64_t zbm_compressed_freed_before_next_snap;
       uint64_t zbm_uncompressed_freed_before_next_snap;

       /* fields used for raw sends */
       uint64_t zbm_ivset_guid;
} zfs_bookmark_phys_t;

The bzero is correct - it's zeroing out zbm_flags and everything after it. I get that the compiler would flag it though - it's worried we're unintentionally trying to overwrite past the end of a field.

[behlendorf]

This appears to be the result of this change which was merged for the 5.18 kernel. Seems like the approved way to address these false positives is to use the new struct_group() macro.

[rhalualani]

I am currently running kernel 5.18.5-1.el8.elrepo.x86_64 for both Oracle8 and CentOS8
and also CentOS9 5.14.0-109.el9.x86_64
with zfs-2.1.99-1 which I got running "git clone https://github.com/zfsonlinux/zfs.git"
To get dkms to build for el8 (el9 was not an issue) I modified 4 files.
edonr.c dsl_bookmark.h dsl_bookmark.c and zfs_log.c
These were all warnings treated as errors.
In edonr.c at line 494 changed
memcpy(hashState224(state)->DoublePipe, i512p2,
to memcpy(hashState512(state)->DoublePipe, i512p2,

In dsl_bookmark.h added struct_group, ie. changed

typedef struct zfs_bookmark_phys {
uint64_t zbm_guid; /* guid of bookmarked dataset /
uint64_t zbm_creation_txg; / birth transaction group /
uint64_t zbm_creation_time; / bookmark creation time */

/* fields used for redacted send / recv */
uint64_t zbm_redaction_obj; /* redaction list object */
uint64_t zbm_flags;     /* ZBM_FLAG_* */

/* fields used for bookmark written size */
uint64_t zbm_referenced_bytes_refd;
uint64_t zbm_compressed_bytes_refd;
uint64_t zbm_uncompressed_bytes_refd;
uint64_t zbm_referenced_freed_before_next_snap;
uint64_t zbm_compressed_freed_before_next_snap;
uint64_t zbm_uncompressed_freed_before_next_snap;

/* fields used for raw sends */
uint64_t zbm_ivset_guid;

} zfs_bookmark_phys_t;

TO:
typedef struct zfs_bookmark_phys {
uint64_t zbm_guid; /* guid of bookmarked dataset /
uint64_t zbm_creation_txg; / birth transaction group /
uint64_t zbm_creation_time; / bookmark creation time */

/* fields used for redacted send / recv */
uint64_t zbm_redaction_obj; /* redaction list object */
struct_group(zbm_group,
uint64_t zbm_flags;     /* ZBM_FLAG_* */

/* fields used for bookmark written size */
uint64_t zbm_referenced_bytes_refd;
uint64_t zbm_compressed_bytes_refd;
uint64_t zbm_uncompressed_bytes_refd;
uint64_t zbm_referenced_freed_before_next_snap;
uint64_t zbm_compressed_freed_before_next_snap;
uint64_t zbm_uncompressed_freed_before_next_snap;

/* fields used for raw sends */
uint64_t zbm_ivset_guid;
); /* end zbm_group group */

} zfs_bookmark_phys_t;

Then in dsl_bookmark.c Changed:
memset(&zbm->zbm_flags, 0,
sizeof (zfs_bookmark_phys_t) -
offsetof(zfs_bookmark_phys_t, zbm_flags));
TO:
memset(&zbm->zbm_group, 0,
sizeof (zbm->zbm_group) );

Finally in zfs_log.c (A little dicey) Changed:
memset(crtime, 0, 2 * sizeof (uint64_t));
scanstamp = (caddr_t)(crtime + 2);
TO:
memset(&crtime[0], 0, 2 * sizeof (uint64_t));
scanstamp = (caddr_t)(&crtime[2]);

Seems to be working fine for both el8 and el9.

[akrherz]

Attempting dkms build of zfs 2.1.5 on 5.18.6-1.el8.elrepo.x86_64 and I get similar warnings / build failures

In file included from ./include/linux/string.h:253,
                 from ./include/linux/bitmap.h:11,
                 from ./include/linux/cpumask.h:12,
                 from ./arch/x86/include/asm/cpumask.h:5,
                 from ./arch/x86/include/asm/msr.h:11,
                 from ./arch/x86/include/asm/processor.h:22,
                 from ./arch/x86/include/asm/timex.h:5,
                 from ./include/linux/timex.h:67,
                 from ./include/linux/time32.h:13,
                 from ./include/linux/time.h:60,
                 from ./include/linux/stat.h:19,
                 from ./include/linux/module.h:13,
                 from /var/lib/dkms/zfs/2.1.5/build/include/os/linux/spl/sys/atomic.h:27,
                 from /var/lib/dkms/zfs/2.1.5/build/include/sys/zfs_context.h:46,
                 from /var/lib/dkms/zfs/2.1.5/build/module/zfs/dsl_bookmark.c:22:
In function ‘fortify_memset_chk’,
    inlined from ‘dsl_bookmark_set_phys’ at /var/lib/dkms/zfs/2.1.5/build/module/zfs/dsl_bookmark.c:384:3:
./include/linux/fortify-string.h:242:4: error: call to ‘__write_overflow_field’ declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror]
    __write_overflow_field(p_size_field, size);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...
In file included from ./include/linux/string.h:253,
                 from /var/lib/dkms/zfs/2.1.5/build/include/os/linux/spl/sys/strings.h:24,
                 from /var/lib/dkms/zfs/2.1.5/build/module/icp/algs/edonr/edonr.c:32:
In function ‘fortify_memcpy_chk’,
    inlined from ‘EdonRInit’ at /var/lib/dkms/zfs/2.1.5/build/module/icp/algs/edonr/edonr.c:491:3:
./include/linux/fortify-string.h:328:4: error: call to ‘__write_overflow_field’ declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror]
    __write_overflow_field(p_size_field, size);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[rhalualani]

Same Here for kernel 5.18.6-1.el8.elrepo.x86_64 building zfs-2.1.5-1
Had to make some changes to build.
in edonr.c line 491
change:
bcopy(i512p2, hashState224(state)->DoublePipe,
To:
bcopy(i512p2, hashState512(state)->DoublePipe,

in dsl_bookmark.c line 384
change:
bzero(&zbm->zbm_flags,
sizeof (zfs_bookmark_phys_t) -
offsetof(zfs_bookmark_phys_t, zbm_flags));
To:
zbm->zbm_flags = 0;
zbm->zbm_referenced_bytes_refd = 0;
zbm->zbm_compressed_bytes_refd = 0;
zbm->zbm_uncompressed_bytes_refd = 0;
zbm->zbm_referenced_freed_before_next_snap = 0;
zbm->zbm_compressed_freed_before_next_snap = 0;
zbm->zbm_uncompressed_freed_before_next_snap = 0;
zbm->zbm_ivset_guid = 0;
in zfs_log.c line 115
change:
void *scanstamp;
To:
uint64_t *scanstamp;
uint8_t *scans;
line 131 change:
bzero(crtime, 2 * sizeof (uint64_t));
scanstamp = (caddr_t)(crtime + 2);
bzero(scanstamp, AV_SCANSTAMP_SZ);
To:
crtime[0] = 0;
crtime[1] = 0;
scanstamp = crtime + 2;
for (i = 0; i != 4; i++, scanstamp++) {
*scanstamp = 0;
}
line 172 change:
bcopy(xoap->xoa_av_scanstamp, scanstamp, AV_SCANSTAMP_SZ);
To:
scans = (uint8_t *)scanstamp;
for (i = 0; i != AV_SCANSTAMP_SZ; i++, scans++) {
*scans = xoap->xoa_av_scanstamp[i];
}
line 178 change:
bcopy(&xoap->xoa_projid, scanstamp, sizeof (uint64_t));
To:
*scanstamp = xoap->xoa_projid;

This now built fine for kernel 5.18.6-1.el8.elrepo.x86_64
and also for kernel CentOS9 5.14.0-115.el9.x86_64
and they both appear to be working fine.

[behlendorf]

A proposed set of changes for this issue can be found in PR #13575.