From: Song Liu <songliubraving@meta.com>
To: Eric Biggers <ebiggers@kernel.org>
Cc: Song Liu <song@kernel.org>, bpf <bpf@vger.kernel.org>,
"fsverity@lists.linux.dev" <fsverity@lists.linux.dev>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@kernel.org>,
Kernel Team <kernel-team@meta.com>, Theodore Ts'o <tytso@mit.edu>,
"roberto.sassu@huaweicloud.com" <roberto.sassu@huaweicloud.com>
Subject: Re: [PATCH v5 bpf-next 5/9] bpf, fsverity: Add kfunc bpf_get_fsverity_digest
Date: Tue, 24 Oct 2023 23:21:14 +0000 [thread overview]
Message-ID: <27D20897-366E-484A-8335-9427FB98B96F@fb.com> (raw)
In-Reply-To: <20231024230337.GA2320@sol.localdomain>
> On Oct 24, 2023, at 4:03 PM, Eric Biggers <ebiggers@kernel.org> wrote:
>
> On Mon, Oct 23, 2023 at 11:30:52PM -0700, Song Liu wrote:
>> fsverity provides fast and reliable hash of files, namely fsverity_digest.
>> The digest can be used by security solutions to verify file contents.
>>
>> Add new kfunc bpf_get_fsverity_digest() so that we can access fsverity from
>> BPF LSM programs. This kfunc is added to fs/verity/measure.c because some
>> data structure used in the function is private to fsverity
>> (fs/verity/fsverity_private.h).
>>
>> To avoid recursion, bpf_get_fsverity_digest is only allowed in BPF LSM
>> programs.
>>
>> Signed-off-by: Song Liu <song@kernel.org>
>> ---
>> fs/verity/fsverity_private.h | 10 +++++
>> fs/verity/init.c | 1 +
>> fs/verity/measure.c | 85 ++++++++++++++++++++++++++++++++++++
>> 3 files changed, 96 insertions(+)
>>
>> diff --git a/fs/verity/fsverity_private.h b/fs/verity/fsverity_private.h
>> index d071a6e32581..f7124f89ab6f 100644
>> --- a/fs/verity/fsverity_private.h
>> +++ b/fs/verity/fsverity_private.h
>> @@ -145,4 +145,14 @@ static inline void fsverity_init_signature(void)
>>
>> void __init fsverity_init_workqueue(void);
>>
>> +/* measure.c */
>> +
>> +#ifdef CONFIG_BPF_SYSCALL
>> +int __init fsverity_init_bpf(void);
>> +#else
>> +static inline int fsverity_init_bpf(void)
>> +{
>> +}
>> +#endif
>
> This does not compile when !CONFIG_BPF_SYSCALL.
>
> fsverity_init_bpf() probably shouldn't have a return value, given that this code
> cannot be compiled as a loadable module. You can either panic on error, or
> ignore the error. I don't think there are any other options.
Got it. Updated fsverity_init_bpf to return void.
>
> Also, please keep the sections of this file in alphabetical order. The
> measure.c section should go between init.c and open.c sections.
>
>
>> diff --git a/fs/verity/measure.c b/fs/verity/measure.c
>> index eec5956141da..4b0617ea0499 100644
>> --- a/fs/verity/measure.c
>> +++ b/fs/verity/measure.c
>> @@ -8,6 +8,8 @@
>> #include "fsverity_private.h"
>>
>> #include <linux/uaccess.h>
>> +#include <linux/bpf.h>
>> +#include <linux/btf.h>
>
> Keep includes in alphabetical order, please.
Fixed in the next version.
Thanks,
Song
next prev parent reply other threads:[~2023-10-24 23:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-24 6:30 [PATCH v5 bpf-next 0/9] bpf: File verification with LSM and fsverity Song Liu
2023-10-24 6:30 ` [PATCH v5 bpf-next 1/9] bpf: Expose bpf_dynptr_slice* kfuncs for in kernel use Song Liu
2023-10-24 6:30 ` [PATCH v5 bpf-next 2/9] bpf: Factor out helper check_reg_const_str() Song Liu
2023-10-24 6:30 ` [PATCH v5 bpf-next 3/9] bpf: Introduce KF_ARG_PTR_TO_CONST_STR Song Liu
2023-10-24 6:30 ` [PATCH v5 bpf-next 4/9] bpf: Add kfunc bpf_get_file_xattr Song Liu
2023-10-24 6:30 ` [PATCH v5 bpf-next 5/9] bpf, fsverity: Add kfunc bpf_get_fsverity_digest Song Liu
2023-10-24 23:03 ` Eric Biggers
2023-10-24 23:21 ` Song Liu [this message]
2023-10-24 6:30 ` [PATCH v5 bpf-next 6/9] Documentation/bpf: Add documentation for filesystem kfuncs Song Liu
2023-10-24 6:30 ` [PATCH v5 bpf-next 7/9] selftests/bpf: Sort config in alphabetic order Song Liu
2023-10-24 6:30 ` [PATCH v5 bpf-next 8/9] selftests/bpf: Add tests for filesystem kfuncs Song Liu
2023-10-24 6:30 ` [PATCH v5 bpf-next 9/9] selftests/bpf: Add test that uses fsverity and xattr to sign a file Song Liu
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