From: Tushar Sugandhi <tusharsu@linux.microsoft.com> To: Mimi Zohar <zohar@linux.ibm.com>, noodles@fb.com, bauermann@kolabnow.com, kexec@lists.infradead.org, linux-integrity@vger.kernel.org Cc: code@tyhicks.com, nramas@linux.microsoft.com, paul@paul-moore.com, Eric Biederman <ebiederm@xmission.com> Subject: Re: [PATCH 01/10] ima: implement function to allocate buffer at kexec load Date: Tue, 11 Jul 2023 10:59:07 -0700 [thread overview] Message-ID: <31eb2a9c-7410-b655-43d2-3b2966d2d3da@linux.microsoft.com> (raw) In-Reply-To: <494dffc6cc7cfb8c6ca78f3bae442d57362a8857.camel@linux.ibm.com> Adding Eric to cc. On 7/7/23 06:00, Mimi Zohar wrote: > Hi Tushar, > > On Mon, 2023-07-03 at 14:57 -0700, Tushar Sugandhi wrote: >> IMA does not provide a mechanism to allocate memory for IMA log storage >> during kexec operation. > The IMA measurement list is currently being carried across kexec, so > obviously a buffer is being allocated for it. IMA not allocating > memory for the measurment list is not the problem statement. Please > concisely provide the problem statement, explaining why IMA needs to > allocate the buffer. > I meant IMA does not provide separate functions to allocate buffer and populate measurements. Both operations are wrapped in an atomic ima_dump_measurement_list(). As I mentioned in the comment in the cover letter, if there is no such technical limitation to allocate the buffer and copy the measurements at kexec ‘execute’ – I will make the necessary code changes and update the above line in the patch description accordingly. >> The function should handle the scenario where >> the kexec load is called multiple times. > Currently the buffer is being freed with the kexec 'unload'. With this > patch IMA is allocating a buffer for the measurement list, which needs > to be freed independently of the kexec 'unload'. If we end up allocating the buffer at kexec ‘execute’ (which results in soft boot to next Kernel) – is it technically possible that kexec ‘unload’ being called after calling kexec ‘execute’? If not, should I still free the buffer at kexec ‘unload’ in this scenario? ~Tushar >> Implement a function to allocate buffer of size kexec_segment_size at >> kexec load. If the buffer was already allocated, free that buffer and >> reallocate. Finally, initialihze ima_khdr struct. >> >> The patch operates under the assumption that the segment size does not >> change between kexec load and execute. >> >> Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
WARNING: multiple messages have this Message-ID (diff)
From: Tushar Sugandhi <tusharsu@linux.microsoft.com> To: Mimi Zohar <zohar@linux.ibm.com>, noodles@fb.com, bauermann@kolabnow.com, kexec@lists.infradead.org, linux-integrity@vger.kernel.org Cc: code@tyhicks.com, nramas@linux.microsoft.com, paul@paul-moore.com, Eric Biederman <ebiederm@xmission.com> Subject: Re: [PATCH 01/10] ima: implement function to allocate buffer at kexec load Date: Tue, 11 Jul 2023 10:59:07 -0700 [thread overview] Message-ID: <31eb2a9c-7410-b655-43d2-3b2966d2d3da@linux.microsoft.com> (raw) In-Reply-To: <494dffc6cc7cfb8c6ca78f3bae442d57362a8857.camel@linux.ibm.com> Adding Eric to cc. On 7/7/23 06:00, Mimi Zohar wrote: > Hi Tushar, > > On Mon, 2023-07-03 at 14:57 -0700, Tushar Sugandhi wrote: >> IMA does not provide a mechanism to allocate memory for IMA log storage >> during kexec operation. > The IMA measurement list is currently being carried across kexec, so > obviously a buffer is being allocated for it. IMA not allocating > memory for the measurment list is not the problem statement. Please > concisely provide the problem statement, explaining why IMA needs to > allocate the buffer. > I meant IMA does not provide separate functions to allocate buffer and populate measurements. Both operations are wrapped in an atomic ima_dump_measurement_list(). As I mentioned in the comment in the cover letter, if there is no such technical limitation to allocate the buffer and copy the measurements at kexec ‘execute’ – I will make the necessary code changes and update the above line in the patch description accordingly. >> The function should handle the scenario where >> the kexec load is called multiple times. > Currently the buffer is being freed with the kexec 'unload'. With this > patch IMA is allocating a buffer for the measurement list, which needs > to be freed independently of the kexec 'unload'. If we end up allocating the buffer at kexec ‘execute’ (which results in soft boot to next Kernel) – is it technically possible that kexec ‘unload’ being called after calling kexec ‘execute’? If not, should I still free the buffer at kexec ‘unload’ in this scenario? ~Tushar >> Implement a function to allocate buffer of size kexec_segment_size at >> kexec load. If the buffer was already allocated, free that buffer and >> reallocate. Finally, initialihze ima_khdr struct. >> >> The patch operates under the assumption that the segment size does not >> change between kexec load and execute. >> >> Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2023-07-11 17:59 UTC|newest] Thread overview: 82+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-07-03 21:56 [PATCH 00/10] ima: measure events between kexec load and execute Tushar Sugandhi 2023-07-03 21:56 ` Tushar Sugandhi 2023-07-03 21:57 ` [PATCH 01/10] ima: implement function to allocate buffer at kexec load Tushar Sugandhi 2023-07-03 21:57 ` Tushar Sugandhi 2023-07-07 13:00 ` Mimi Zohar 2023-07-07 13:00 ` Mimi Zohar 2023-07-11 17:59 ` Tushar Sugandhi [this message] 2023-07-11 17:59 ` Tushar Sugandhi 2023-07-11 21:11 ` Mimi Zohar 2023-07-11 21:11 ` Mimi Zohar 2023-07-12 19:49 ` Tushar Sugandhi 2023-07-12 19:49 ` Tushar Sugandhi 2023-07-03 21:57 ` [PATCH 02/10] ima: implement function to populate buffer at kexec execute Tushar Sugandhi 2023-07-03 21:57 ` Tushar Sugandhi 2023-07-07 13:00 ` Mimi Zohar 2023-07-07 13:00 ` Mimi Zohar 2023-07-11 18:05 ` Tushar Sugandhi 2023-07-11 18:05 ` Tushar Sugandhi 2023-07-03 21:57 ` [PATCH 03/10] ima: allocate buffer at kexec load to hold ima measurements Tushar Sugandhi 2023-07-03 21:57 ` Tushar Sugandhi 2023-07-07 13:01 ` Mimi Zohar 2023-07-07 13:01 ` Mimi Zohar 2023-07-11 18:31 ` Tushar Sugandhi 2023-07-11 18:31 ` Tushar Sugandhi 2023-07-11 20:16 ` Stefan Berger 2023-07-11 20:16 ` Stefan Berger 2023-07-12 19:39 ` Tushar Sugandhi 2023-07-12 19:39 ` Tushar Sugandhi 2023-07-03 21:57 ` [PATCH 04/10] ima: implement functions to suspend and resume measurements Tushar Sugandhi 2023-07-03 21:57 ` Tushar Sugandhi 2023-07-03 21:57 ` [PATCH 05/10] kexec: implement functions to map and unmap segment to kimage Tushar Sugandhi 2023-07-03 21:57 ` Tushar Sugandhi 2023-07-07 12:28 ` Stefan Berger 2023-07-07 12:28 ` Stefan Berger 2023-07-11 18:41 ` Tushar Sugandhi 2023-07-11 18:41 ` Tushar Sugandhi 2023-07-11 19:19 ` Stefan Berger 2023-07-11 19:19 ` Stefan Berger 2023-07-12 19:51 ` Tushar Sugandhi 2023-07-12 19:51 ` Tushar Sugandhi 2023-07-03 21:57 ` [PATCH 06/10] ima: update buffer at kexec execute with ima measurements Tushar Sugandhi 2023-07-03 21:57 ` Tushar Sugandhi 2023-07-07 15:01 ` Mimi Zohar 2023-07-07 15:01 ` Mimi Zohar 2023-07-07 19:49 ` Mimi Zohar 2023-07-07 19:49 ` Mimi Zohar 2023-07-11 19:08 ` Tushar Sugandhi 2023-07-11 19:08 ` Tushar Sugandhi 2023-07-12 15:45 ` Mimi Zohar 2023-07-12 15:45 ` Mimi Zohar 2023-07-11 19:05 ` Tushar Sugandhi 2023-07-11 19:05 ` Tushar Sugandhi 2023-07-03 21:57 ` [PATCH 07/10] ima: remove function ima_dump_measurement_list Tushar Sugandhi 2023-07-03 21:57 ` Tushar Sugandhi 2023-07-07 13:55 ` Mimi Zohar 2023-07-07 13:55 ` Mimi Zohar 2023-07-11 19:11 ` Tushar Sugandhi 2023-07-11 19:11 ` Tushar Sugandhi 2023-07-03 21:57 ` [PATCH 08/10] ima: implement and register a reboot notifier function to update kexec buffer Tushar Sugandhi 2023-07-03 21:57 ` Tushar Sugandhi 2023-07-03 21:57 ` [PATCH 09/10] ima: suspend measurements while the kexec buffer is being copied Tushar Sugandhi 2023-07-03 21:57 ` Tushar Sugandhi 2023-07-03 21:57 ` [PATCH 10/10] kexec: update kexec_file_load syscall to call ima_kexec_post_load Tushar Sugandhi 2023-07-03 21:57 ` Tushar Sugandhi 2023-07-07 8:20 ` RuiRui Yang 2023-07-07 8:20 ` RuiRui Yang 2023-07-11 19:14 ` Tushar Sugandhi 2023-07-11 19:14 ` Tushar Sugandhi 2023-07-12 1:28 ` RuiRui Yang 2023-07-12 1:28 ` RuiRui Yang 2023-07-12 19:30 ` Tushar Sugandhi 2023-07-12 19:30 ` Tushar Sugandhi 2023-07-07 8:18 ` [PATCH 00/10] ima: measure events between kexec load and execute Dave Young 2023-07-07 8:18 ` Dave Young 2023-07-11 17:52 ` Tushar Sugandhi 2023-07-11 17:52 ` Tushar Sugandhi 2023-07-07 15:55 ` Mimi Zohar 2023-07-07 15:55 ` Mimi Zohar 2023-07-11 17:51 ` Tushar Sugandhi 2023-07-11 17:51 ` Tushar Sugandhi 2023-09-22 18:59 ` Tushar Sugandhi 2023-09-22 18:59 ` Tushar Sugandhi
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=31eb2a9c-7410-b655-43d2-3b2966d2d3da@linux.microsoft.com \ --to=tusharsu@linux.microsoft.com \ --cc=bauermann@kolabnow.com \ --cc=code@tyhicks.com \ --cc=ebiederm@xmission.com \ --cc=kexec@lists.infradead.org \ --cc=linux-integrity@vger.kernel.org \ --cc=noodles@fb.com \ --cc=nramas@linux.microsoft.com \ --cc=paul@paul-moore.com \ --cc=zohar@linux.ibm.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.