Changes in Makefile

f34d086f - module: Fix KCOV-ignored file name

Tue, 11 Jun 2024 07:50:32 +0000

module: Fix KCOV-ignored file namemodule.c was renamed to main.c, but the Makefile directive was copy-pastedverbatim with the old file name. Fix up the file name.Fixes: cfc1d277891e ("module: Move all into module/")Signed-off-by: Dmitry Vyukov Signed-off-by: Thomas Gleixner Reviewed-by: Alexander Potapenko Reviewed-by: Marco Elver Reviewed-by: Andrey Konovalov Cc: stable@vger.kernel.orgLink: https://lore.kernel.org/all/bc0cf790b4839c5e38e2fafc64271f620568a39e.1718092070.git.dvyukov@google.com List of files: /linux-6.15/kernel/module/Makefile

8660484e - module: add debugging auto-load duplicate module support

Fri, 14 Apr 2023 05:28:39 +0000

module: add debugging auto-load duplicate module supportThe finit_module() system call can in the worst case use up to more thantwice of a module's size in virtual memory. Duplicate finit_module()system calls are non fatal, however they unnecessarily strain virtualmemory during bootup and in the worst case can cause a system to failto boot. This is only known to currently be an issue on systems withlarger number of CPUs.To help debug this situation we need to consider the different sources forfinit_module(). Requests from the kernel that rely on module auto-loading,ie, the kernel's *request_module() API, are one source of calls. Althoughmodprobe checks to see if a module is already loaded prior to callingfinit_module() there is a small race possible allowing userspace totrigger multiple modprobe calls racing against modprobe and this notseeing the module yet loaded.This adds debugging support to the kernel module auto-loader (*request_module()calls) to easily detect duplicate module requests. To aid with possible bootupfailure issues incurred by this, it will converge duplicates requests to asingle request. This avoids any possible strain on virtual memory duringbootup which could be incurred by duplicate module autoloading requests.Folks debugging virtual memory abuse on bootup can and should enablethis to see what pr_warn()s come on, to see if module auto-loading is toblame for their wores. If they see duplicates they can further debug thisby enabling the module.enable_dups_trace kernel parameter or by enablingCONFIG_MODULE_DEBUG_AUTOLOAD_DUPS_TRACE.Current evidence seems to point to only a few duplicates for moduleauto-loading. And so the source for other duplicates creating heavyvirtual memory pressure due to larger number of CPUs should becomingfrom another place (likely udev).Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

df3e764d - module: add debug stats to help identify memory pressure

Wed, 29 Mar 2023 03:03:19 +0000

module: add debug stats to help identify memory pressureLoading modules with finit_module() can end up using vmalloc(), vmap()and vmalloc() again, for a total of up to 3 separate allocations in theworst case for a single module. We always kernel_read*() the module,that's a vmalloc(). Then vmap() is used for the module decompression,and if so the last read buffer is freed as we use the now decompressedmodule buffer to stuff data into our copy module. The last allocation isspecific to each architectures but pretty much that's generally a seriesof vmalloc() calls or a variation of vmalloc to handle ELF sections withspecial permissions.Evaluation with new stress-ng module support [1] with just 100 opsis proving that you can end up using GiBs of data easily even with allcare we have in the kernel and userspace today in trying to not load moduleswhich are already loaded. 100 ops seems to resemble the sort of pressure asystem with about 400 CPUs can create on module loading. Although issuesrelating to duplicate module requests due to each CPU inucurring a newmodule reuest is silly and some of these are being fixed, we currently lackproper tooling to help diagnose easily what happened, when it happenedand who likely is to blame -- userspace or kernel module autoloading.Provide an initial set of stats which use debugfs to let us easily scrapepost-boot information about failed loads. This sort of information canbe used on production worklaods to try to optimize *avoiding* redundantmemory pressure using finit_module().There's a few examples that can be provided:A 255 vCPU system without the next patch in this series applied:Startup finished in 19.143s (kernel) + 7.078s (userspace) = 26.221sgraphical.target reached after 6.988s in userspaceAnd 13.58 GiB of virtual memory space lost due to failed module loading:root@big ~ # cat /sys/kernel/debug/modules/stats Mods ever loaded 67 Mods failed on kread 0Mods failed on decompress 0 Mods failed on becoming 0 Mods failed on load 1411 Total module size 11464704 Total mod text size 4194304 Failed kread bytes 0 Failed decompress bytes 0 Failed becoming bytes 0 Failed kmod bytes 14588526272 Virtual mem wasted bytes 14588526272 Average mod size 171115 Average mod text size 62602 Average fail load bytes 10339140Duplicate failed modules: module-name How-many-times Reason kvm_intel 249 Load kvm 249 Load irqbypass 8 Load crct10dif_pclmul 128 Load ghash_clmulni_intel 27 Load sha512_ssse3 50 Load sha512_generic 200 Load aesni_intel 249 Load crypto_simd 41 Load cryptd 131 Load evdev 2 Load serio_raw 1 Load virtio_pci 3 Load nvme 3 Load nvme_core 3 Load virtio_pci_legacy_dev 3 Load virtio_pci_modern_dev 3 Load t10_pi 3 Load virtio 3 Load crc32_pclmul 6 Load crc64_rocksoft 3 Load crc32c_intel 40 Load virtio_ring 3 Load crc64 3 LoadThe following screen shot, of a simple 8vcpu 8 GiB KVM guest with thenext patch in this series applied, shows 226.53 MiB are wasted in virtualmemory allocations which due to duplicate module requests during boot.It also shows an average module memory size of 167.10 KiB and an anaverage module .text + .init.text size of 61.13 KiB. The end shows allmodules which were detected as duplicate requests and whether or notthey failed early after just the first kernel_read*() call or late afterwe've already allocated the private space for the module inlayout_and_allocate(). A system with module decompression would revealmore wasted virtual memory space.We should put effort now into identifying the source of these duplicatemodule requests and trimming these down as much possible. Larger systemswill obviously show much more wasted virtual memory allocations.root@kmod ~ # cat /sys/kernel/debug/modules/stats Mods ever loaded 67 Mods failed on kread 0Mods failed on decompress 0 Mods failed on becoming 83 Mods failed on load 16 Total module size 11464704 Total mod text size 4194304 Failed kread bytes 0 Failed decompress bytes 0 Failed becoming bytes 228959096 Failed kmod bytes 8578080 Virtual mem wasted bytes 237537176 Average mod size 171115 Average mod text size 62602 Avg fail becoming bytes 2758544 Average fail load bytes 536130Duplicate failed modules: module-name How-many-times Reason kvm_intel 7 Becoming kvm 7 Becoming irqbypass 6 Becoming & Load crct10dif_pclmul 7 Becoming & Load ghash_clmulni_intel 7 Becoming & Load sha512_ssse3 6 Becoming & Load sha512_generic 7 Becoming & Load aesni_intel 7 Becoming crypto_simd 7 Becoming & Load cryptd 3 Becoming & Load evdev 1 Becoming serio_raw 1 Becoming nvme 3 Becoming nvme_core 3 Becoming t10_pi 3 Becoming virtio_pci 3 Becoming crc32_pclmul 6 Becoming & Load crc64_rocksoft 3 Becoming crc32c_intel 3 Becoming virtio_pci_modern_dev 2 Becoming virtio_pci_legacy_dev 1 Becoming crc64 2 Becoming virtio 2 Becoming virtio_ring 2 Becoming[0] https://github.com/ColinIanKing/stress-ng.git[1] echo 0 > /proc/sys/vm/oom_dump_tasks ./stress-ng --module 100 --module-name xfsSigned-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

25be451a - module: fold usermode helper kmod into modules directory

Sun, 19 Mar 2023 21:35:42 +0000

module: fold usermode helper kmod into modules directoryThe kernel/kmod.c is already only built if we enabled modules, sojust stuff it under kernel/module/kmod.c and unify the MAINTAINERSfile for it.Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

99bd9956 - module: Introduce module unload taint tracking

Mon, 02 May 2022 20:52:52 +0000

module: Introduce module unload taint trackingCurrently, only the initial module that tainted the kernel isrecorded e.g. when an out-of-tree module is loaded.The purpose of this patch is to allow the kernel to maintain a record ofeach unloaded module that taints the kernel. So, in addition todisplaying a list of linked modules (see print_modules()) e.g. in theevent of a detected bad page, unloaded modules that carried a taint/ortaints are displayed too. A tainted module unload count is maintained.The number of tracked modules is not fixed. This feature is disabled bydefault.Signed-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

32a08c17 - module: Move module_enable_x() and frob_text() in strict_rwx.c

Wed, 23 Feb 2022 09:00:59 +0000

module: Move module_enable_x() and frob_text() in strict_rwx.cMove module_enable_x() together with module_enable_nx() andmodule_enable_ro().Those three functions are going together, they are all usedto set up the correct page flags on the different sections.As module_enable_x() is used independently ofCONFIG_STRICT_MODULE_RWX, build strict_rwx.c all the time anduse IS_ENABLED(CONFIG_STRICT_MODULE_RWX) when relevant.Signed-off-by: Christophe Leroy Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

47889798 - module: Move version support into a separate file

Tue, 22 Mar 2022 14:03:44 +0000

module: Move version support into a separate fileNo functional change.This patch migrates module version support out of core code intokernel/module/version.c. In addition simple code refactoring tomake this possible.Reviewed-by: Christophe Leroy Signed-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

f64205a4 - module: Move kdb module related code out of main kdb code

Tue, 22 Mar 2022 14:03:43 +0000

module: Move kdb module related code out of main kdb codeNo functional change.This patch migrates the kdb 'lsmod' command support out of mainkdb code into its own file under kernel/module. In addition tothe above, a minor style warning i.e. missing a blank line afterdeclarations, was resolved too. The new file was added toMAINTAINERS. Finally we remove linux/module.h as it is entirelyredundant.Reviewed-by: Daniel Thompson Acked-by: Daniel Thompson Signed-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

44c09535 - module: Move sysfs support into a separate file

Tue, 22 Mar 2022 14:03:42 +0000

module: Move sysfs support into a separate fileNo functional change.This patch migrates module sysfs support out of core code intokernel/module/sysfs.c. In addition simple code refactoring tomake this possible.Reviewed-by: Christophe Leroy Signed-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

0ffc40f6 - module: Move procfs support into a separate file

Tue, 22 Mar 2022 14:03:41 +0000

module: Move procfs support into a separate fileNo functional change.This patch migrates code that allows one to generate alist of loaded/or linked modules via /proc when procfssupport is enabled into kernel/module/procfs.c.Reviewed-by: Christophe Leroy Signed-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

91fb02f3 - module: Move kallsyms support into a separate file

Tue, 22 Mar 2022 14:03:39 +0000

module: Move kallsyms support into a separate fileNo functional change.This patch migrates kallsyms code out of core modulecode kernel/module/kallsyms.cSigned-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

473c84d1 - module: Move kmemleak support to a separate file

Tue, 22 Mar 2022 14:03:38 +0000

module: Move kmemleak support to a separate fileNo functional change.This patch migrates kmemleak code out of core modulecode into kernel/module/debug_kmemleak.cReviewed-by: Christophe Leroy Signed-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

b33465fe - module: Move strict rwx support to a separate file

Tue, 22 Mar 2022 14:03:36 +0000

module: Move strict rwx support to a separate fileNo functional change.This patch migrates code that makes module textand rodata memory read-only and non-text memorynon-executable from core module code intokernel/module/strict_rwx.c.Reviewed-by: Christophe Leroy Signed-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

58d208de - module: Move latched RB-tree support to a separate file

Tue, 22 Mar 2022 14:03:35 +0000

module: Move latched RB-tree support to a separate fileNo functional change.This patch migrates module latched RB-tree support(e.g. see __module_address()) from core module codeinto kernel/module/tree_lookup.c.Reviewed-by: Christophe Leroy Signed-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

1be9473e - module: Move livepatch support to a separate file

Tue, 22 Mar 2022 14:03:34 +0000

module: Move livepatch support to a separate fileNo functional change.This patch migrates livepatch support (i.e. used during moduleadd/or load and remove/or deletion) from core module code intokernel/module/livepatch.c. At the moment it contains code topersist Elf information about a given livepatch module, only.The new file was added to MAINTAINERS.Reviewed-by: Petr Mladek Tested-by: Petr Mladek Signed-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile

cfc1d277 - module: Move all into module/

Tue, 22 Mar 2022 14:03:31 +0000

module: Move all into module/No functional changes.This patch moves all module related code into a separate directory,modifies each file name and creates a new Makefile. Note: this effortis in preparation to refactor core module code.Reviewed-by: Christophe Leroy Signed-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain List of files: /linux-6.15/kernel/module/Makefile