8 Commits

Author	SHA1	Message	Date
Linus Torvalds	b6a7828502	modules-6.4-rc1 ... The summary of the changes for this pull requests is: * Song Liu's new struct module_memory replacement * Nick Alcock's MODULE_LICENSE() removal for non-modules * My cleanups and enhancements to reduce the areas where we vmalloc module memory for duplicates, and the respective debug code which proves the remaining vmalloc pressure comes from userspace. Most of the changes have been in linux-next for quite some time except the minor fixes I made to check if a module was already loaded prior to allocating the final module memory with vmalloc and the respective debug code it introduces to help clarify the issue. Although the functional change is small it is rather safe as it can only *help* reduce vmalloc space for duplicates and is confirmed to fix a bootup issue with over 400 CPUs with KASAN enabled. I don't expect stable kernels to pick up that fix as the cleanups would have also had to have been picked up. Folks on larger CPU systems with modules will want to just upgrade if vmalloc space has been an issue on bootup. Given the size of this request, here's some more elaborate details on this pull request. The functional change change in this pull request is the very first patch from Song Liu which replaces the struct module_layout with a new struct module memory. The old data structure tried to put together all types of supported module memory types in one data structure, the new one abstracts the differences in memory types in a module to allow each one to provide their own set of details. This paves the way in the future so we can deal with them in a cleaner way. If you look at changes they also provide a nice cleanup of how we handle these different memory areas in a module. This change has been in linux-next since before the merge window opened for v6.3 so to provide more than a full kernel cycle of testing. It's a good thing as quite a bit of fixes have been found for it. Jason Baron then made dynamic debug a first class citizen module user by using module notifier callbacks to allocate / remove module specific dynamic debug information. Nick Alcock has done quite a bit of work cross-tree to remove module license tags from things which cannot possibly be module at my request so to: a) help him with his longer term tooling goals which require a deterministic evaluation if a piece a symbol code could ever be part of a module or not. But quite recently it is has been made clear that tooling is not the only one that would benefit. Disambiguating symbols also helps efforts such as live patching, kprobes and BPF, but for other reasons and R&D on this area is active with no clear solution in sight. b) help us inch closer to the now generally accepted long term goal of automating all the MODULE_LICENSE() tags from SPDX license tags In so far as a) is concerned, although module license tags are a no-op for non-modules, tools which would want create a mapping of possible modules can only rely on the module license tag after the commit 8b41fc4454 ("kbuild: create modules.builtin without Makefile.modbuiltin or tristate.conf"). Nick has been working on this *for years* and AFAICT I was the only one to suggest two alternatives to this approach for tooling. The complexity in one of my suggested approaches lies in that we'd need a possible-obj-m and a could-be-module which would check if the object being built is part of any kconfig build which could ever lead to it being part of a module, and if so define a new define -DPOSSIBLE_MODULE [0]. A more obvious yet theoretical approach I've suggested would be to have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as well but that means getting kconfig symbol names mapping to modules always, and I don't think that's the case today. I am not aware of Nick or anyone exploring either of these options. Quite recently Josh Poimboeuf has pointed out that live patching, kprobes and BPF would benefit from resolving some part of the disambiguation as well but for other reasons. The function granularity KASLR (fgkaslr) patches were mentioned but Joe Lawrence has clarified this effort has been dropped with no clear solution in sight [1]. In the meantime removing module license tags from code which could never be modules is welcomed for both objectives mentioned above. Some developers have also welcomed these changes as it has helped clarify when a module was never possible and they forgot to clean this up, and so you'll see quite a bit of Nick's patches in other pull requests for this merge window. I just picked up the stragglers after rc3. LWN has good coverage on the motivation behind this work [2] and the typical cross-tree issues he ran into along the way. The only concrete blocker issue he ran into was that we should not remove the MODULE_LICENSE() tags from files which have no SPDX tags yet, even if they can never be modules. Nick ended up giving up on his efforts due to having to do this vetting and backlash he ran into from folks who really did *not understand* the core of the issue nor were providing any alternative / guidance. I've gone through his changes and dropped the patches which dropped the module license tags where an SPDX license tag was missing, it only consisted of 11 drivers. To see if a pull request deals with a file which lacks SPDX tags you can just use: ./scripts/spdxcheck.py -f \ $(git diff --name-only commid-id | xargs echo) You'll see a core module file in this pull request for the above, but that's not related to his changes. WE just need to add the SPDX license tag for the kernel/module/kmod.c file in the future but it demonstrates the effectiveness of the script. Most of Nick's changes were spread out through different trees, and I just picked up the slack after rc3 for the last kernel was out. Those changes have been in linux-next for over two weeks. The cleanups, debug code I added and final fix I added for modules were motivated by David Hildenbrand's report of boot failing on a systems with over 400 CPUs when KASAN was enabled due to running out of virtual memory space. Although the functional change only consists of 3 lines in the patch "module: avoid allocation if module is already present and ready", proving that this was the best we can do on the modules side took quite a bit of effort and new debug code. The initial cleanups I did on the modules side of things has been in linux-next since around rc3 of the last kernel, the actual final fix for and debug code however have only been in linux-next for about a week or so but I think it is worth getting that code in for this merge window as it does help fix / prove / evaluate the issues reported with larger number of CPUs. Userspace is not yet fixed as it is taking a bit of time for folks to understand the crux of the issue and find a proper resolution. Worst come to worst, I have a kludge-of-concept [3] of how to make kernel_read*() calls for modules unique / converge them, but I'm currently inclined to just see if userspace can fix this instead. [0] https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [1] https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [2] https://lwn.net/Articles/927569/ [3] https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org -----BEGIN PGP SIGNATURE----- iQJGBAABCgAwFiEENnNq2KuOejlQLZofziMdCjCSiKcFAmRG4m0SHG1jZ3JvZkBr ZXJuZWwub3JnAAoJEM4jHQowkoinQ2oP/0xlvKwJg6Ey8fHZF0qv8VOskE80zoLF hMazU3xfqLA+1TQvouW1YBxt3jwS3t1Ehs+NrV+nY9Yzcm0MzRX/n3fASJVe7nRr oqWWQU+voYl5Pw1xsfdp6C8IXpBQorpYby3Vp0MAMoZyl2W2YrNo36NV488wM9KC jD4HF5Z6xpnPSZTRR7AgW9mo7FdAtxPeKJ76Bch7lH8U6omT7n36WqTw+5B1eAYU YTOvrjRs294oqmWE+LeebyiOOXhH/yEYx4JNQgCwPdxwnRiGJWKsk5va0hRApqF/ WW8dIqdEnjsa84lCuxnmWgbcPK8cgmlO0rT0DyneACCldNlldCW1LJ0HOwLk9pea p3JFAsBL7TKue4Tos6I7/4rx1ufyBGGIigqw9/VX5g0Iif+3BhWnqKRfz+p9wiMa Fl7cU6u7yC68CHu1HBSisK16cYMCPeOnTSd89upHj8JU/t74O6k/ARvjrQ9qmNUt c5U+OY+WpNJ1nXQydhY/yIDhFdYg8SSpNuIO90r4L8/8jRQYXNG80FDd1UtvVDuy eq0r2yZ8C0XHSlOT9QHaua/tWV/aaKtyC/c0hDRrigfUrq8UOlGujMXbUnrmrWJI tLJLAc7ePWAAoZXGSHrt0U27l029GzLwRdKqJ6kkDANVnTeOdV+mmBg9zGh3/Mp6 agiwdHUMVN7X =56WK -----END PGP SIGNATURE----- Merge tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull module updates from Luis Chamberlain: "The summary of the changes for this pull requests is: - Song Liu's new struct module_memory replacement - Nick Alcock's MODULE_LICENSE() removal for non-modules - My cleanups and enhancements to reduce the areas where we vmalloc module memory for duplicates, and the respective debug code which proves the remaining vmalloc pressure comes from userspace. Most of the changes have been in linux-next for quite some time except the minor fixes I made to check if a module was already loaded prior to allocating the final module memory with vmalloc and the respective debug code it introduces to help clarify the issue. Although the functional change is small it is rather safe as it can only *help* reduce vmalloc space for duplicates and is confirmed to fix a bootup issue with over 400 CPUs with KASAN enabled. I don't expect stable kernels to pick up that fix as the cleanups would have also had to have been picked up. Folks on larger CPU systems with modules will want to just upgrade if vmalloc space has been an issue on bootup. Given the size of this request, here's some more elaborate details: The functional change change in this pull request is the very first patch from Song Liu which replaces the 'struct module_layout' with a new 'struct module_memory'. The old data structure tried to put together all types of supported module memory types in one data structure, the new one abstracts the differences in memory types in a module to allow each one to provide their own set of details. This paves the way in the future so we can deal with them in a cleaner way. If you look at changes they also provide a nice cleanup of how we handle these different memory areas in a module. This change has been in linux-next since before the merge window opened for v6.3 so to provide more than a full kernel cycle of testing. It's a good thing as quite a bit of fixes have been found for it. Jason Baron then made dynamic debug a first class citizen module user by using module notifier callbacks to allocate / remove module specific dynamic debug information. Nick Alcock has done quite a bit of work cross-tree to remove module license tags from things which cannot possibly be module at my request so to: a) help him with his longer term tooling goals which require a deterministic evaluation if a piece a symbol code could ever be part of a module or not. But quite recently it is has been made clear that tooling is not the only one that would benefit. Disambiguating symbols also helps efforts such as live patching, kprobes and BPF, but for other reasons and R&D on this area is active with no clear solution in sight. b) help us inch closer to the now generally accepted long term goal of automating all the MODULE_LICENSE() tags from SPDX license tags In so far as a) is concerned, although module license tags are a no-op for non-modules, tools which would want create a mapping of possible modules can only rely on the module license tag after the commit 8b41fc4454 ("kbuild: create modules.builtin without Makefile.modbuiltin or tristate.conf"). Nick has been working on this *for years* and AFAICT I was the only one to suggest two alternatives to this approach for tooling. The complexity in one of my suggested approaches lies in that we'd need a possible-obj-m and a could-be-module which would check if the object being built is part of any kconfig build which could ever lead to it being part of a module, and if so define a new define -DPOSSIBLE_MODULE [0]. A more obvious yet theoretical approach I've suggested would be to have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as well but that means getting kconfig symbol names mapping to modules always, and I don't think that's the case today. I am not aware of Nick or anyone exploring either of these options. Quite recently Josh Poimboeuf has pointed out that live patching, kprobes and BPF would benefit from resolving some part of the disambiguation as well but for other reasons. The function granularity KASLR (fgkaslr) patches were mentioned but Joe Lawrence has clarified this effort has been dropped with no clear solution in sight [1]. In the meantime removing module license tags from code which could never be modules is welcomed for both objectives mentioned above. Some developers have also welcomed these changes as it has helped clarify when a module was never possible and they forgot to clean this up, and so you'll see quite a bit of Nick's patches in other pull requests for this merge window. I just picked up the stragglers after rc3. LWN has good coverage on the motivation behind this work [2] and the typical cross-tree issues he ran into along the way. The only concrete blocker issue he ran into was that we should not remove the MODULE_LICENSE() tags from files which have no SPDX tags yet, even if they can never be modules. Nick ended up giving up on his efforts due to having to do this vetting and backlash he ran into from folks who really did *not understand* the core of the issue nor were providing any alternative / guidance. I've gone through his changes and dropped the patches which dropped the module license tags where an SPDX license tag was missing, it only consisted of 11 drivers. To see if a pull request deals with a file which lacks SPDX tags you can just use: ./scripts/spdxcheck.py -f \ $(git diff --name-only commid-id | xargs echo) You'll see a core module file in this pull request for the above, but that's not related to his changes. WE just need to add the SPDX license tag for the kernel/module/kmod.c file in the future but it demonstrates the effectiveness of the script. Most of Nick's changes were spread out through different trees, and I just picked up the slack after rc3 for the last kernel was out. Those changes have been in linux-next for over two weeks. The cleanups, debug code I added and final fix I added for modules were motivated by David Hildenbrand's report of boot failing on a systems with over 400 CPUs when KASAN was enabled due to running out of virtual memory space. Although the functional change only consists of 3 lines in the patch "module: avoid allocation if module is already present and ready", proving that this was the best we can do on the modules side took quite a bit of effort and new debug code. The initial cleanups I did on the modules side of things has been in linux-next since around rc3 of the last kernel, the actual final fix for and debug code however have only been in linux-next for about a week or so but I think it is worth getting that code in for this merge window as it does help fix / prove / evaluate the issues reported with larger number of CPUs. Userspace is not yet fixed as it is taking a bit of time for folks to understand the crux of the issue and find a proper resolution. Worst come to worst, I have a kludge-of-concept [3] of how to make kernel_read*() calls for modules unique / converge them, but I'm currently inclined to just see if userspace can fix this instead" Link: https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [0] Link: https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [1] Link: https://lwn.net/Articles/927569/ [2] Link: https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org [3] * tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (121 commits) module: add debugging auto-load duplicate module support module: stats: fix invalid_mod_bytes typo module: remove use of uninitialized variable len module: fix building stats for 32-bit targets module: stats: include uapi/linux/module.h module: avoid allocation if module is already present and ready module: add debug stats to help identify memory pressure module: extract patient module check into helper modules/kmod: replace implementation with a semaphore Change DEFINE_SEMAPHORE() to take a number argument module: fix kmemleak annotations for non init ELF sections module: Ignore L0 and rename is_arm_mapping_symbol() module: Move is_arm_mapping_symbol() to module_symbol.h module: Sync code of is_arm_mapping_symbol() scripts/gdb: use mem instead of core_layout to get the module address interconnect: remove module-related code interconnect: remove MODULE_LICENSE in non-modules zswap: remove MODULE_LICENSE in non-modules zpool: remove MODULE_LICENSE in non-modules x86/mm/dump_pagetables: remove MODULE_LICENSE in non-modules ...	2023-04-27 16:36:55 -07:00
Peter Zijlstra	48380368de	Change DEFINE_SEMAPHORE() to take a number argument ... Fundamentally semaphores are a counted primitive, but DEFINE_SEMAPHORE() does not expose this and explicitly creates a binary semaphore. Change DEFINE_SEMAPHORE() to take a number argument and use that in the few places that open-coded it using __SEMAPHORE_INITIALIZER(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> [mcgrof: add some tribal knowledge about why some folks prefer binary sempahores over mutexes] Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>	2023-04-18 11:15:24 -07:00
Jithu Joseph	5210fb4e18	platform/x86/intel/ifs: Sysfs interface for Array BIST ... The interface to trigger Array BIST test and obtain its result is similar to the existing scan test. The only notable difference is that, Array BIST doesn't require any test content to be loaded. So binary load related options are not needed for this test. Add sysfs interface for array BIST test, the testing support will be added by subsequent patch. Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://lore.kernel.org/r/20230322003359.213046-7-jithu.joseph@intel.com Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>	2023-03-27 16:10:20 +02:00
Jithu Joseph	d847eddf0e	platform/x86/intel/ifs: IFS cleanup ... Cleanup incorporating misc review comments - Remove the subdirectory intel_ifs/0 for devicenode [1] - Make plat_ifs_groups non static and use it directly without using a function [2] Link: https://lore.kernel.org/lkml/Y+4kQOtrHt5pdsSO@kroah.com/ [1] Link: https://lore.kernel.org/lkml/Y9nyxNesVHCUXAcH@kroah.com/ [2] Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20230322003359.213046-4-jithu.joseph@intel.com Signed-off-by: Hans de Goede <hdegoede@redhat.com>	2023-03-27 16:10:20 +02:00
Jithu Joseph	4fb858f3dc	platform/x86/intel/ifs: Add current_batch sysfs entry ... Initial implementation assumed a single IFS test image file with a fixed name ff-mm-ss.scan. (where ff, mm, ss refers to family, model and stepping of the core). Subsequently, it became evident that supporting more than one test image file is needed to provide more comprehensive test coverage. (Test coverage in this scenario refers to testing more transistors in the core to identify faults). The other alternative of increasing the size of a single scan test image file would not work as the upper bound is limited by the size of memory area reserved by BIOS for loading IFS test image. Introduce "current_batch" file which accepts a number. Writing a number to the current_batch file would load the test image file by name ff-mm-ss-<xy>.scan, where <xy> is the number written to the "current_batch" file in hex. Range check of the input is done to verify it not greater than 0xff. For e.g if the scan test image comprises of 6 files, they would be named: 06-8f-06-01.scan 06-8f-06-02.scan 06-8f-06-03.scan 06-8f-06-04.scan 06-8f-06-05.scan 06-8f-06-06.scan And writing 3 to current_batch would result in loading 06-8f-06-03.scan above. The file can also be read to know the currently loaded file. And testing a system looks like: for each scan file do load the IFS test image file (write to the batch file) for each core do test the core with this set of tests done done Qualify few error messages with the test image file suffix to provide better context. [ bp: Massage commit message. Add link to the discussion. ] Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20221107225323.2733518-13-jithu.joseph@intel.com	2022-11-19 11:29:00 +01:00
Jithu Joseph	bf835ee852	platform/x86/intel/ifs: Remove reload sysfs entry ... Reload sysfs entry will be replaced by current_batch, drop it. Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20221117035935.4136738-14-jithu.joseph@intel.com	2022-11-19 11:23:53 +01:00
Jithu Joseph	a4c30fa4ea	platform/x86/intel/ifs: Remove image loading during init ... IFS test image is unnecessarily loaded during driver initialization. Drop image loading during ifs_init() and improve module load time. With this change, user has to load one when starting the tests. As a consequence, make ifs_sem static as it is only used within sysfs.c Suggested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20221117035935.4136738-4-jithu.joseph@intel.com	2022-11-18 21:37:04 +01:00
Jithu Joseph	6f33a92b92	platform/x86/intel/ifs: Add IFS sysfs interface ... Implement sysfs interface to trigger ifs test for a specific cpu. Additional interfaces related to checking the status of the scan test and seeing the version of the loaded IFS binary are also added. The basic usage is as below. - To start test, for example on cpu5: echo 5 > /sys/devices/platform/intel_ifs/run_test - To see the status of the last test cat /sys/devices/platform/intel_ifs/status - To see the version of the loaded scan binary cat /sys/devices/platform/intel_ifs/image_version Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> Co-developed-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Acked-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220506225410.1652287-10-tony.luck@intel.com Signed-off-by: Hans de Goede <hdegoede@redhat.com>	2022-05-12 15:35:29 +02:00