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2022-02-23module/ftrace: handle patchable-function-entryMark Rutland
commit a1326b17ac03a9012cb3d01e434aacb4d67a416c upstream. When using patchable-function-entry, the compiler will record the callsites into a section named "__patchable_function_entries" rather than "__mcount_loc". Let's abstract this difference behind a new FTRACE_CALLSITE_SECTION, so that architectures don't have to handle this explicitly (e.g. with custom module linker scripts). As parisc currently handles this explicitly, it is fixed up accordingly, with its custom linker script removed. Since FTRACE_CALLSITE_SECTION is only defined when DYNAMIC_FTRACE is selected, the parisc module loading code is updated to only use the definition in that case. When DYNAMIC_FTRACE is not selected, modules shouldn't have this section, so this removes some redundant work in that case. To make sure that this is keep up-to-date for modules and the main kernel, a comment is added to vmlinux.lds.h, with the existing ifdeffery simplified for legibility. I built parisc generic-{32,64}bit_defconfig with DYNAMIC_FTRACE enabled, and verified that the section made it into the .ko files for modules. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Helge Deller <deller@gmx.de> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Torsten Duwe <duwe@suse.de> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Tested-by: Sven Schnelle <svens@stackframe.org> Tested-by: Torsten Duwe <duwe@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: linux-parisc@vger.kernel.org Cc: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-23Revert "module, async: async_synchronize_full() on module init iff async is ↵Igor Pylypiv
used" [ Upstream commit 67d6212afda218d564890d1674bab28e8612170f ] This reverts commit 774a1221e862b343388347bac9b318767336b20b. We need to finish all async code before the module init sequence is done. In the reverted commit the PF_USED_ASYNC flag was added to mark a thread that called async_schedule(). Then the PF_USED_ASYNC flag was used to determine whether or not async_synchronize_full() needs to be invoked. This works when modprobe thread is calling async_schedule(), but it does not work if module dispatches init code to a worker thread which then calls async_schedule(). For example, PCI driver probing is invoked from a worker thread based on a node where device is attached: if (cpu < nr_cpu_ids) error = work_on_cpu(cpu, local_pci_probe, &ddi); else error = local_pci_probe(&ddi); We end up in a situation where a worker thread gets the PF_USED_ASYNC flag set instead of the modprobe thread. As a result, async_synchronize_full() is not invoked and modprobe completes without waiting for the async code to finish. The issue was discovered while loading the pm80xx driver: (scsi_mod.scan=async) modprobe pm80xx worker ... do_init_module() ... pci_call_probe() work_on_cpu(local_pci_probe) local_pci_probe() pm8001_pci_probe() scsi_scan_host() async_schedule() worker->flags |= PF_USED_ASYNC; ... < return from worker > ... if (current->flags & PF_USED_ASYNC) <--- false async_synchronize_full(); Commit 21c3c5d28007 ("block: don't request module during elevator init") fixed the deadlock issue which the reverted commit 774a1221e862 ("module, async: async_synchronize_full() on module init iff async is used") tried to fix. Since commit 0fdff3ec6d87 ("async, kmod: warn on synchronous request_module() from async workers") synchronous module loading from async is not allowed. Given that the original deadlock issue is fixed and it is no longer allowed to call synchronous request_module() from async we can remove PF_USED_ASYNC flag to make module init consistently invoke async_synchronize_full() unless async module probe is requested. Signed-off-by: Igor Pylypiv <ipylypiv@google.com> Reviewed-by: Changyuan Lyu <changyuanl@google.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30module: limit enabling module.sig_enforceMimi Zohar
[ Upstream commit 0c18f29aae7ce3dadd26d8ee3505d07cc982df75 ] Irrespective as to whether CONFIG_MODULE_SIG is configured, specifying "module.sig_enforce=1" on the boot command line sets "sig_enforce". Only allow "sig_enforce" to be set when CONFIG_MODULE_SIG is configured. This patch makes the presence of /sys/module/module/parameters/sig_enforce dependent on CONFIG_MODULE_SIG=y. Fixes: fda784e50aac ("module: export module signature enforcement status") Reported-by: Nayna Jain <nayna@linux.ibm.com> Tested-by: Mimi Zohar <zohar@linux.ibm.com> Tested-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-11modules: inherit TAINT_PROPRIETARY_MODULEChristoph Hellwig
commit 262e6ae7081df304fc625cf368d5c2cbba2bb991 upstream. If a TAINT_PROPRIETARY_MODULE exports symbol, inherit the taint flag for all modules importing these symbols, and don't allow loading symbols from TAINT_PROPRIETARY_MODULE modules if the module previously imported gplonly symbols. Add a anti-circumvention devices so people don't accidentally get themselves into trouble this way. Comment from Greg: "Ah, the proven-to-be-illegal "GPL Condom" defense :)" [jeyu: pr_info -> pr_err and pr_warn as per discussion] Link: http://lore.kernel.org/r/20200730162957.GA22469@lst.de Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11modules: return licensing information from find_symbolChristoph Hellwig
commit ef1dac6021cc8ec5de02ce31722bf26ac4ed5523 upstream. Report the GPLONLY status through a new argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11modules: rename the licence field in struct symsearch to licenseChristoph Hellwig
commit cd8732cdcc37d7077c4fa2c966b748c0662b607e upstream. Use the same spelling variant as the rest of the file. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11modules: unexport __module_addressChristoph Hellwig
commit 34e64705ad415ed7a816e60ef62b42fe6d1729d9 upstream. __module_address is only used by built-in code. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11modules: unexport __module_text_addressChristoph Hellwig
commit 3fe1e56d0e68b623dd62d8d38265d2a052e7e185 upstream. __module_text_address is only used by built-in code. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11modules: mark each_symbol_section staticChristoph Hellwig
commit a54e04914c211b5678602a46b3ede5d82ec1327d upstream. each_symbol_section is only used inside of module.c. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11modules: mark find_symbol staticChristoph Hellwig
commit 773110470e2fa3839523384ae014f8a723c4d178 upstream. find_symbol is only used in module.c. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11modules: mark ref_module staticChristoph Hellwig
commit 7ef5264de773279b9f23b6cc8afb5addb30e970b upstream. ref_module isn't used anywhere outside of module.c. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-07module: harden ELF info handlingFrank van der Linden
[ Upstream commit ec2a29593c83ed71a7f16e3243941ebfcf75fdf6 ] 5fdc7db644 ("module: setup load info before module_sig_check()") moved the ELF setup, so that it was done before the signature check. This made the module name available to signature error messages. However, the checks for ELF correctness in setup_load_info are not sufficient to prevent bad memory references due to corrupted offset fields, indices, etc. So, there's a regression in behavior here: a corrupt and unsigned (or badly signed) module, which might previously have been rejected immediately, can now cause an oops/crash. Harden ELF handling for module loading by doing the following: - Move the signature check back up so that it comes before ELF initialization. It's best to do the signature check to see if we can trust the module, before using the ELF structures inside it. This also makes checks against info->len more accurate again, as this field will be reduced by the length of the signature in mod_check_sig(). The module name is now once again not available for error messages during the signature check, but that seems like a fair tradeoff. - Check if sections have offset / size fields that at least don't exceed the length of the module. - Check if sections have section name offsets that don't fall outside the section name table. - Add a few other sanity checks against invalid section indices, etc. This is not an exhaustive consistency check, but the idea is to at least get through the signature and blacklist checks without crashing because of corrupted ELF info, and to error out gracefully for most issues that would have caused problems later on. Fixes: 5fdc7db6448a ("module: setup load info before module_sig_check()") Signed-off-by: Frank van der Linden <fllinden@amazon.com> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-07module: avoid *goto*s in module_sig_check()Sergey Shtylyov
[ Upstream commit 10ccd1abb808599a6dc7c9389560016ea3568085 ] Let's move the common handling of the non-fatal errors after the *switch* statement -- this avoids *goto*s inside that *switch*... Suggested-by: Joe Perches <joe@perches.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-07module: merge repetitive strings in module_sig_check()Sergey Shtylyov
[ Upstream commit 705e9195187d85249fbb0eaa844b1604a98fbc9a ] The 'reason' variable in module_sig_check() points to 3 strings across the *switch* statement, all needlessly starting with the same text. Let's put the starting text into the pr_notice() call -- it saves 21 bytes of the object code (x86 gcc 10.2.1). Suggested-by: Joe Perches <joe@perches.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-07modsign: print module name along with error messageJessica Yu
[ Upstream commit e9f35f634e099894f4d6c3b039cd3de5281ee637 ] It is useful to know which module failed signature verification, so print the module name along with the error message. Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04module: Ignore _GLOBAL_OFFSET_TABLE_ when warning for undefined symbolsFangrui Song
commit ebfac7b778fac8b0e8e92ec91d0b055f046b4604 upstream. clang-12 -fno-pic (since https://github.com/llvm/llvm-project/commit/a084c0388e2a59b9556f2de0083333232da3f1d6) can emit `call __stack_chk_fail@PLT` instead of `call __stack_chk_fail` on x86. The two forms should have identical behaviors on x86-64 but the former causes GNU as<2.37 to produce an unreferenced undefined symbol _GLOBAL_OFFSET_TABLE_. (On x86-32, there is an R_386_PC32 vs R_386_PLT32 difference but the linker behavior is identical as far as Linux kernel is concerned.) Simply ignore _GLOBAL_OFFSET_TABLE_ for now, like what scripts/mod/modpost.c:ignore_undef_symbol does. This also fixes the problem for gcc/clang -fpie and -fpic, which may emit `call foo@PLT` for external function calls on x86. Note: ld -z defs and dynamic loaders do not error for unreferenced undefined symbols so the module loader is reading too much. If we ever need to ignore more symbols, the code should be refactored to ignore unreferenced symbols. Cc: <stable@vger.kernel.org> Link: https://github.com/ClangBuiltLinux/linux/issues/1250 Link: https://sourceware.org/bugzilla/show_bug.cgi?id=27178 Reported-by: Marco Elver <elver@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Marco Elver <elver@google.com> Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-06module: delay kobject uevent until after module init callJessica Yu
[ Upstream commit 38dc717e97153e46375ee21797aa54777e5498f3 ] Apparently there has been a longstanding race between udev/systemd and the module loader. Currently, the module loader sends a uevent right after sysfs initialization, but before the module calls its init function. However, some udev rules expect that the module has initialized already upon receiving the uevent. This race has been triggered recently (see link in references) in some systemd mount unit files. For instance, the configfs module creates the /sys/kernel/config mount point in its init function, however the module loader issues the uevent before this happens. sys-kernel-config.mount expects to be able to mount /sys/kernel/config upon receipt of the module loading uevent, but if the configfs module has not called its init function yet, then this directory will not exist and the mount unit fails. A similar situation exists for sys-fs-fuse-connections.mount, as the fuse sysfs mount point is created during the fuse module's init function. If udev is faster than module initialization then the mount unit would fail in a similar fashion. To fix this race, delay the module KOBJ_ADD uevent until after the module has finished calling its init routine. References: https://github.com/systemd/systemd/issues/17586 Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-By: Nicolas Morey-Chaisemartin <nmoreychaisemartin@suse.com> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06module: set MODULE_STATE_GOING state when a module fails to loadMiroslav Benes
[ Upstream commit 5e8ed280dab9eeabc1ba0b2db5dbe9fe6debb6b5 ] If a module fails to load due to an error in prepare_coming_module(), the following error handling in load_module() runs with MODULE_STATE_COMING in module's state. Fix it by correctly setting MODULE_STATE_GOING under "bug_cleanup" label. Signed-off-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29module: statically initialize init section freeing dataDaniel Jordan
[ Upstream commit fdf09ab887829cd1b671e45d9549f8ec1ffda0fa ] Corentin hit the following workqueue warning when running with CRYPTO_MANAGER_EXTRA_TESTS: WARNING: CPU: 2 PID: 147 at kernel/workqueue.c:1473 __queue_work+0x3b8/0x3d0 Modules linked in: ghash_generic CPU: 2 PID: 147 Comm: modprobe Not tainted 5.6.0-rc1-next-20200214-00068-g166c9264f0b1-dirty #545 Hardware name: Pine H64 model A (DT) pc : __queue_work+0x3b8/0x3d0 Call trace: __queue_work+0x3b8/0x3d0 queue_work_on+0x6c/0x90 do_init_module+0x188/0x1f0 load_module+0x1d00/0x22b0 I wasn't able to reproduce on x86 or rpi 3b+. This is WARN_ON(!list_empty(&work->entry)) from __queue_work(), and it happens because the init_free_wq work item isn't initialized in time for a crypto test that requests the gcm module. Some crypto tests were recently moved earlier in boot as explained in commit c4741b230597 ("crypto: run initcalls for generic implementations earlier"), which went into mainline less than two weeks before the Fixes commit. Avoid the warning by statically initializing init_free_wq and the corresponding llist. Link: https://lore.kernel.org/lkml/20200217204803.GA13479@Red/ Fixes: 1a7b7d922081 ("modules: Use vmalloc special flag") Reported-by: Corentin Labbe <clabbe.montjoie@gmail.com> Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com> Tested-on: sun50i-h6-pine-h64 Tested-on: imx8mn-ddr4-evk Tested-on: sun50i-a64-bananapi-m64 Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01module: Remove accidental change of module_enable_x()Steven Rostedt (VMware)
[ Upstream commit af74262337faa65d5ac2944553437d3f5fb29123 ] When pulling in Divya Indi's patch, I made a minor fix to remove unneeded braces. I commited my fix up via "git commit -a --amend". Unfortunately, I didn't realize I had some changes I was testing in the module code, and those changes were applied to Divya's patch as well. This reverts the accidental updates to the module code. Cc: Jessica Yu <jeyu@kernel.org> Cc: Divya Indi <divya.indi@oracle.com> Reported-by: Peter Zijlstra <peterz@infradead.org> Fixes: e585e6469d6f ("tracing: Verify if trace array exists before destroying it.") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01tracing: Verify if trace array exists before destroying it.Divya Indi
[ Upstream commit e585e6469d6f476b82aa148dc44aaf7ae269a4e2 ] A trace array can be destroyed from userspace or kernel. Verify if the trace array exists before proceeding to destroy/remove it. Link: http://lkml.kernel.org/r/1565805327-579-3-git-send-email-divya.indi@oracle.com Reviewed-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Signed-off-by: Divya Indi <divya.indi@oracle.com> [ Removed unneeded braces ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21module: Correctly truncate sysfs sections outputKees Cook
commit 11990a5bd7e558e9203c1070fc52fb6f0488e75b upstream. The only-root-readable /sys/module/$module/sections/$section files did not truncate their output to the available buffer size. While most paths into the kernfs read handlers end up using PAGE_SIZE buffers, it's possible to get there through other paths (e.g. splice, sendfile). Actually limit the output to the "count" passed into the read function, and report it back correctly. *sigh* Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/lkml/20200805002015.GE23458@shao2-debian Fixes: ed66f991bb19 ("module: Refactor section attr into bin attribute") Cc: stable@vger.kernel.org Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-16module: Do not expose section addresses to non-CAP_SYSLOGKees Cook
commit b25a7c5af9051850d4f3d93ca500056ab6ec724b upstream. The printing of section addresses in /sys/module/*/sections/* was not using the correct credentials to evaluate visibility. Before: # cat /sys/module/*/sections/.*text 0xffffffffc0458000 ... # capsh --drop=CAP_SYSLOG -- -c "cat /sys/module/*/sections/.*text" 0xffffffffc0458000 ... After: # cat /sys/module/*/sections/*.text 0xffffffffc0458000 ... # capsh --drop=CAP_SYSLOG -- -c "cat /sys/module/*/sections/.*text" 0x0000000000000000 ... Additionally replaces the existing (safe) /proc/modules check with file->f_cred for consistency. Reported-by: Dominik Czarnota <dominik.czarnota@trailofbits.com> Fixes: be71eda5383f ("module: Fix display of wrong module .text address") Cc: stable@vger.kernel.org Tested-by: Jessica Yu <jeyu@kernel.org> Acked-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-16module: Refactor section attr into bin attributeKees Cook
commit ed66f991bb19d94cae5d38f77de81f96aac7813f upstream. In order to gain access to the open file's f_cred for kallsym visibility permission checks, refactor the module section attributes to use the bin_attribute instead of attribute interface. Additionally removes the redundant "name" struct member. Cc: stable@vger.kernel.org Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Jessica Yu <jeyu@kernel.org> Acked-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-16kallsyms: Refactor kallsyms_show_value() to take credKees Cook
commit 160251842cd35a75edfb0a1d76afa3eb674ff40a upstream. In order to perform future tests against the cred saved during open(), switch kallsyms_show_value() to operate on a cred, and have all current callers pass current_cred(). This makes it very obvious where callers are checking the wrong credential in their "read" contexts. These will be fixed in the coming patches. Additionally switch return value to bool, since it is always used as a direct permission check, not a 0-on-success, negative-on-error style function return. Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-24module: avoid setting info->name early in case we can fall back to ↵Jessica Yu
info->mod->name [ Upstream commit 708e0ada1916be765b7faa58854062f2bc620bbf ] In setup_load_info(), info->name (which contains the name of the module, mostly used for early logging purposes before the module gets set up) gets unconditionally assigned if .modinfo is missing despite the fact that there is an if (!info->name) check near the end of the function. Avoid assigning a placeholder string to info->name if .modinfo doesn't exist, so that we can fall back to info->mod->name later on. Fixes: 5fdc7db6448a ("module: setup load info before module_sig_check()") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24modules: lockdep: Suppress suspicious RCU usage warningMasami Hiramatsu
[ Upstream commit bf08949cc8b98b7d1e20cfbba169a5938d42dae8 ] While running kprobe module test, find_module_all() caused a suspicious RCU usage warning. ----- ============================= WARNING: suspicious RCU usage 5.4.0-next-20191202+ #63 Not tainted ----------------------------- kernel/module.c:619 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by rmmod/642: #0: ffffffff8227da80 (module_mutex){+.+.}, at: __x64_sys_delete_module+0x9a/0x230 stack backtrace: CPU: 0 PID: 642 Comm: rmmod Not tainted 5.4.0-next-20191202+ #63 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x71/0xa0 find_module_all+0xc1/0xd0 __x64_sys_delete_module+0xac/0x230 ? do_syscall_64+0x12/0x1f0 do_syscall_64+0x50/0x1f0 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4b6d49 ----- This is because list_for_each_entry_rcu(modules) is called without rcu_read_lock(). This is safe because the module_mutex is locked. Pass lockdep_is_held(&module_mutex) to the list_for_each_entry_rcu() to suppress this warning, This also fixes similar issue in mod_find() and each_symbol_section(). Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24kernel/module: Fix memleak in module_add_modinfo_attrs()YueHaibing
[ Upstream commit f6d061d617124abbd55396a3bc37b9bf7d33233c ] In module_add_modinfo_attrs() if sysfs_create_file() fails on the first iteration of the loop (so i = 0), we forget to free the modinfo_attrs. Fixes: bc6f2a757d52 ("kernel/module: Fix mem leak in module_add_modinfo_attrs") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-09kernel/module.c: wakeup processes in module_wq on module unloadKonstantin Khorenko
commit 5d603311615f612320bb77bd2a82553ef1ced5b7 upstream. Fix the race between load and unload a kernel module. sys_delete_module() try_stop_module() mod->state = _GOING add_unformed_module() old = find_module_all() (old->state == _GOING => wait_event_interruptible()) During pre-condition finished_loading() rets 0 schedule() (never gets waken up later) free_module() mod->state = _UNFORMED list_del_rcu(&mod->list) (dels mod from "modules" list) return The race above leads to modprobe hanging forever on loading a module. Error paths on loading module call wake_up_all(&module_wq) after freeing module, so let's do the same on straight module unload. Fixes: 6e6de3dee51a ("kernel/module.c: Only return -EEXIST for modules that have finished loading") Reviewed-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-28Merge branch 'next-lockdown' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...
2019-09-27Merge branch 'next-integrity' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity Pull integrity updates from Mimi Zohar: "The major feature in this time is IMA support for measuring and appraising appended file signatures. In addition are a couple of bug fixes and code cleanup to use struct_size(). In addition to the PE/COFF and IMA xattr signatures, the kexec kernel image may be signed with an appended signature, using the same scripts/sign-file tool that is used to sign kernel modules. Similarly, the initramfs may contain an appended signature. This contained a lot of refactoring of the existing appended signature verification code, so that IMA could retain the existing framework of calculating the file hash once, storing it in the IMA measurement list and extending the TPM, verifying the file's integrity based on a file hash or signature (eg. xattrs), and adding an audit record containing the file hash, all based on policy. (The IMA support for appended signatures patch set was posted and reviewed 11 times.) The support for appended signature paves the way for adding other signature verification methods, such as fs-verity, based on a single system-wide policy. The file hash used for verifying the signature and the signature, itself, can be included in the IMA measurement list" * 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: ima: ima_api: Use struct_size() in kzalloc() ima: use struct_size() in kzalloc() sefltest/ima: support appended signatures (modsig) ima: Fix use after free in ima_read_modsig() MODSIGN: make new include file self contained ima: fix freeing ongoing ahash_request ima: always return negative code for error ima: Store the measurement again when appraising a modsig ima: Define ima-modsig template ima: Collect modsig ima: Implement support for module-style appended signatures ima: Factor xattr_verify() out of ima_appraise_measurement() ima: Add modsig appraise_type option for module-style appended signatures integrity: Select CONFIG_KEYS instead of depending on it PKCS#7: Introduce pkcs7_get_digest() PKCS#7: Refactor verify_pkcs7_signature() MODSIGN: Export module signature definitions ima: initialize the "template" field with the default template
2019-09-11module: remove unneeded casts in cmp_name()Masahiro Yamada
You can pass opaque pointers directly. I also renamed 'va' and 'vb' into more meaningful arguments. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-09-11module: Fix link failure due to invalid relocation on namespace offsetWill Deacon
Commit 8651ec01daed ("module: add support for symbol namespaces.") broke linking for arm64 defconfig: | lib/crypto/arc4.o: In function `__ksymtab_arc4_setkey': | arc4.c:(___ksymtab+arc4_setkey+0x8): undefined reference to `no symbol' | lib/crypto/arc4.o: In function `__ksymtab_arc4_crypt': | arc4.c:(___ksymtab+arc4_crypt+0x8): undefined reference to `no symbol' This is because the dummy initialisation of the 'namespace_offset' field in 'struct kernel_symbol' when using EXPORT_SYMBOL on architectures with support for PREL32 locations uses an offset from an absolute address (0) in an effort to trick 'offset_to_pointer' into behaving as a NOP, allowing non-namespaced symbols to be treated in the same way as those belonging to a namespace. Unfortunately, place-relative relocations require a symbol reference rather than an absolute value and, although x86 appears to get away with this due to placing the kernel text at the top of the address space, it almost certainly results in a runtime failure if the kernel is relocated dynamically as a result of KASLR. Rework 'namespace_offset' so that a value of 0, which cannot occur for a valid namespaced symbol, indicates that the corresponding symbol does not belong to a namespace. Cc: Matthias Maennich <maennich@google.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Fixes: 8651ec01daed ("module: add support for symbol namespaces.") Reported-by: kbuild test robot <lkp@intel.com> Tested-by: Matthias Maennich <maennich@google.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matthias Maennich <maennich@google.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-09-10module: add config option MODULE_ALLOW_MISSING_NAMESPACE_IMPORTSMatthias Maennich
If MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS is enabled (default=n), the requirement for modules to import all namespaces that are used by the module is relaxed. Enabling this option effectively allows (invalid) modules to be loaded while only a warning is emitted. Disabling this option keeps the enforcement at module loading time and loading is denied if the module's imports are not satisfactory. Reviewed-by: Martijn Coenen <maco@android.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Matthias Maennich <maennich@google.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-09-10module: add support for symbol namespaces.Matthias Maennich
The EXPORT_SYMBOL_NS() and EXPORT_SYMBOL_NS_GPL() macros can be used to export a symbol to a specific namespace. There are no _GPL_FUTURE and _UNUSED variants because these are currently unused, and I'm not sure they are necessary. I didn't add EXPORT_SYMBOL_NS() for ASM exports; this patch sets the namespace of ASM exports to NULL by default. In case of relative references, it will be relocatable to NULL. If there's a need, this should be pretty easy to add. A module that wants to use a symbol exported to a namespace must add a MODULE_IMPORT_NS() statement to their module code; otherwise, modpost will complain when building the module, and the kernel module loader will emit an error and fail when loading the module. MODULE_IMPORT_NS() adds a modinfo tag 'import_ns' to the module. That tag can be observed by the modinfo command, modpost and kernel/module.c at the time of loading the module. The ELF symbols are renamed to include the namespace with an asm label; for example, symbol 'usb_stor_suspend' in namespace USB_STORAGE becomes 'usb_stor_suspend.USB_STORAGE'. This allows modpost to do namespace checking, without having to go through all the effort of parsing ELF and relocation records just to get to the struct kernel_symbols. On x86_64 I saw no difference in binary size (compression), but at runtime this will require a word of memory per export to hold the namespace. An alternative could be to store namespaced symbols in their own section and use a separate 'struct namespaced_kernel_symbol' for that section, at the cost of making the module loader more complex. Co-developed-by: Martijn Coenen <maco@android.com> Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Matthias Maennich <maennich@google.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-09-10module: support reading multiple values per modinfo tagMatthias Maennich
Similar to modpost's get_next_modinfo(), introduce get_next_modinfo() in kernel/module.c to acquire any further values associated with the same modinfo tag name. That is useful for any tags that have multiple occurrences (such as 'alias'), but is in particular introduced here as part of the symbol namespaces patch series to read the (potentially) multiple namespaces a module is importing. Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Martijn Coenen <maco@android.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Matthias Maennich <maennich@google.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-08-21modules: page-align module section allocations only for arches supporting ↵He Zhe
strict module rwx We should keep the case of "#define debug_align(X) (X)" for all arches without CONFIG_HAS_STRICT_MODULE_RWX ability, which would save people, who are sensitive to system size, a lot of memory when using modules, especially for embedded systems. This is also the intention of the original #ifdef... statement and still valid for now. Note that this still keeps the effect of the fix of the following commit, 38f054d549a8 ("modules: always page-align module section allocations"), since when CONFIG_ARCH_HAS_STRICT_MODULE_RWX is enabled, module pages are aligned. Signed-off-by: He Zhe <zhe.he@windriver.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-08-19lockdown: Enforce module signatures if the kernel is locked downDavid Howells
If the kernel is locked down, require that all modules have valid signatures that we can verify. I have adjusted the errors generated: (1) If there's no signature (ENODATA) or we can't check it (ENOPKG, ENOKEY), then: (a) If signatures are enforced then EKEYREJECTED is returned. (b) If there's no signature or we can't check it, but the kernel is locked down then EPERM is returned (this is then consistent with other lockdown cases). (2) If the signature is unparseable (EBADMSG, EINVAL), the signature fails the check (EKEYREJECTED) or a system error occurs (eg. ENOMEM), we return the error we got. Note that the X.509 code doesn't check for key expiry as the RTC might not be valid or might not have been transferred to the kernel's clock yet. [Modified by Matthew Garrett to remove the IMA integration. This will be replaced with integration with the IMA architecture policy patchset.] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Matthew Garrett <matthewgarrett@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Jessica Yu <jeyu@kernel.org> Signed-off-by: James Morris <jmorris@namei.org>
2019-08-05MODSIGN: Export module signature definitionsThiago Jung Bauermann
IMA will use the module_signature format for append signatures, so export the relevant definitions and factor out the code which verifies that the appended signature trailer is valid. Also, create a CONFIG_MODULE_SIG_FORMAT option so that IMA can select it and be able to use mod_check_sig() without having to depend on either CONFIG_MODULE_SIG or CONFIG_MODULES. s390 duplicated the definition of struct module_signature so now they can use the new <linux/module_signature.h> header instead. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Acked-by: Jessica Yu <jeyu@kernel.org> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-07-30modules: always page-align module section allocationsJessica Yu
Some arches (e.g., arm64, x86) have moved towards non-executable module_alloc() allocations for security hardening reasons. That means that the module loader will need to set the text section of a module to executable, regardless of whether or not CONFIG_STRICT_MODULE_RWX is set. When CONFIG_STRICT_MODULE_RWX=y, module section allocations are always page-aligned to handle memory rwx permissions. On some arches with CONFIG_STRICT_MODULE_RWX=n however, when setting the module text to executable, the BUG_ON() in frob_text() gets triggered since module section allocations are not page-aligned when CONFIG_STRICT_MODULE_RWX=n. Since the set_memory_* API works with pages, and since we need to call set_memory_x() regardless of whether CONFIG_STRICT_MODULE_RWX is set, we might as well page-align all module section allocations for ease of managing rwx permissions of module sections (text, rodata, etc). Fixes: 2eef1399a866 ("modules: fix BUG when load module with rodata=n") Reported-by: Martin Kaiser <lists@kaiser.cx> Reported-by: Bartosz Golaszewski <brgl@bgdev.pl> Tested-by: David Lechner <david@lechnology.com> Tested-by: Martin Kaiser <martin@kaiser.cx> Tested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-07-18Merge tag 'modules-for-v5.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull module updates from Jessica Yu: "Summary of modules changes for the 5.3 merge window: - Code fixes and cleanups - Fix bug where set_memory_x() wasn't being called when rodata=n - Fix bug where -EEXIST was being returned for going modules - Allow arches to override module_exit_section()" * tag 'modules-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: modules: fix compile error if don't have strict module rwx ARM: module: recognize unwind exit sections module: allow arch overrides for .exit section names modules: fix BUG when load module with rodata=n kernel/module: Fix mem leak in module_add_modinfo_attrs kernel: module: Use struct_size() helper kernel/module.c: Only return -EEXIST for modules that have finished loading
2019-06-28Merge branch 'for-mingo' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull rcu/next + tools/memory-model changes from Paul E. McKenney: - RCU flavor consolidation cleanups and optmizations - Documentation updates - Miscellaneous fixes - SRCU updates - RCU-sync flavor consolidation - Torture-test updates - Linux-kernel memory-consistency-model updates, most notably the addition of plain C-language accesses Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-26modules: fix compile error if don't have strict module rwxYang Yingliang
If CONFIG_ARCH_HAS_STRICT_MODULE_RWX is not defined, we need stub for module_enable_nx() and module_enable_x(). If CONFIG_ARCH_HAS_STRICT_MODULE_RWX is defined, but CONFIG_STRICT_MODULE_RWX is disabled, we need stub for module_enable_nx. Move frob_text() outside of the CONFIG_STRICT_MODULE_RWX, because it is needed anyway. Fixes: 2eef1399a866 ("modules: fix BUG when load module with rodata=n") Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-06-24module: allow arch overrides for .exit section namesMatthias Schiffer
Some archs like ARM store unwind information for .exit.text in sections with unusual names. As this unwind information refers to .exit.text, it must not be loaded when .exit.text is not loaded (when CONFIG_MODULE_UNLOAD is unset); otherwise, loading a module can fail due to relocation failures. Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-06-24modules: fix BUG when load module with rodata=nYang Yingliang
When loading a module with rodata=n, it causes an executing NX-protected page BUG. [ 32.379191] kernel tried to execute NX-protected page - exploit attempt? (uid: 0) [ 32.382917] BUG: unable to handle page fault for address: ffffffffc0005000 [ 32.385947] #PF: supervisor instruction fetch in kernel mode [ 32.387662] #PF: error_code(0x0011) - permissions violation [ 32.389352] PGD 240c067 P4D 240c067 PUD 240e067 PMD 421a52067 PTE 8000000421a53063 [ 32.391396] Oops: 0011 [#1] SMP PTI [ 32.392478] CPU: 7 PID: 2697 Comm: insmod Tainted: G O 5.2.0-rc5+ #202 [ 32.394588] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 32.398157] RIP: 0010:ko_test_init+0x0/0x1000 [ko_test] [ 32.399662] Code: Bad RIP value. [ 32.400621] RSP: 0018:ffffc900029f3ca8 EFLAGS: 00010246 [ 32.402171] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 32.404332] RDX: 00000000000004c7 RSI: 0000000000000cc0 RDI: ffffffffc0005000 [ 32.406347] RBP: ffffffffc0005000 R08: ffff88842fbebc40 R09: ffffffff810ede4a [ 32.408392] R10: ffffea00108e3480 R11: 0000000000000000 R12: ffff88842bee21a0 [ 32.410472] R13: 0000000000000001 R14: 0000000000000001 R15: ffffc900029f3e78 [ 32.412609] FS: 00007fb4f0c0a700(0000) GS:ffff88842fbc0000(0000) knlGS:0000000000000000 [ 32.414722] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 32.416290] CR2: ffffffffc0004fd6 CR3: 0000000421a90004 CR4: 0000000000020ee0 [ 32.418471] Call Trace: [ 32.419136] do_one_initcall+0x41/0x1df [ 32.420199] ? _cond_resched+0x10/0x40 [ 32.421433] ? kmem_cache_alloc_trace+0x36/0x160 [ 32.422827] do_init_module+0x56/0x1f7 [ 32.423946] load_module+0x1e67/0x2580 [ 32.424947] ? __alloc_pages_nodemask+0x150/0x2c0 [ 32.426413] ? map_vm_area+0x2d/0x40 [ 32.427530] ? __vmalloc_node_range+0x1ef/0x260 [ 32.428850] ? __do_sys_init_module+0x135/0x170 [ 32.430060] ? _cond_resched+0x10/0x40 [ 32.431249] __do_sys_init_module+0x135/0x170 [ 32.432547] do_syscall_64+0x43/0x120 [ 32.433853] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Because if rodata=n, set_memory_x() can't be called, fix this by calling set_memory_x in complete_formation(); Fixes: f2c65fb3221a ("x86/modules: Avoid breaking W^X while loading modules") Suggested-by: Jian Cheng <cj.chengjian@huawei.com> Reviewed-by: Nadav Amit <namit@vmware.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-06-14kernel/module: Fix mem leak in module_add_modinfo_attrsYueHaibing
In module_add_modinfo_attrs if sysfs_create_file fails, we forget to free allocated modinfo_attrs and roll back the sysfs files. Fixes: 03e88ae1b13d ("[PATCH] fix module sysfs files reference counting") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-06-07kernel: module: Use struct_size() helperGustavo A. R. Silva
One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct module_sect_attrs { ... struct module_sect_attr attrs[0]; }; Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. So, replace the following form: sizeof(*sect_attrs) + nloaded * sizeof(sect_attrs->attrs[0] with: struct_size(sect_attrs, attrs, nloaded) This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-06-05kernel/module.c: Only return -EEXIST for modules that have finished loadingPrarit Bhargava
Microsoft HyperV disables the X86_FEATURE_SMCA bit on AMD systems, and linux guests boot with repeated errors: amd64_edac_mod: Unknown symbol amd_unregister_ecc_decoder (err -2) amd64_edac_mod: Unknown symbol amd_register_ecc_decoder (err -2) amd64_edac_mod: Unknown symbol amd_report_gart_errors (err -2) amd64_edac_mod: Unknown symbol amd_unregister_ecc_decoder (err -2) amd64_edac_mod: Unknown symbol amd_register_ecc_decoder (err -2) amd64_edac_mod: Unknown symbol amd_report_gart_errors (err -2) The warnings occur because the module code erroneously returns -EEXIST for modules that have failed to load and are in the process of being removed from the module list. module amd64_edac_mod has a dependency on module edac_mce_amd. Using modules.dep, systemd will load edac_mce_amd for every request of amd64_edac_mod. When the edac_mce_amd module loads, the module has state MODULE_STATE_UNFORMED and once the module load fails and the state becomes MODULE_STATE_GOING. Another request for edac_mce_amd module executes and add_unformed_module() will erroneously return -EEXIST even though the previous instance of edac_mce_amd has MODULE_STATE_GOING. Upon receiving -EEXIST, systemd attempts to load amd64_edac_mod, which fails because of unknown symbols from edac_mce_amd. add_unformed_module() must wait to return for any case other than MODULE_STATE_LIVE to prevent a race between multiple loads of dependent modules. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Barret Rhoden <brho@google.com> Cc: David Arcari <darcari@redhat.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-28srcu: Allocate per-CPU data for DEFINE_SRCU() in modulesPaul E. McKenney
Adding DEFINE_SRCU() or DEFINE_STATIC_SRCU() to a loadable module requires that the size of the reserved region be increased, which is not something we want to be doing all that often. One approach would be to require that loadable modules define an srcu_struct and invoke init_srcu_struct() from their module_init function and cleanup_srcu_struct() from their module_exit function. However, this is more than a bit user unfriendly. This commit therefore creates an ___srcu_struct_ptrs linker section, and pointers to srcu_struct structures created by DEFINE_SRCU() and DEFINE_STATIC_SRCU() within a module are placed into that module's ___srcu_struct_ptrs section. The required init_srcu_struct() and cleanup_srcu_struct() functions are then automatically invoked as needed when that module is loaded and unloaded, thus allowing modules to continue to use DEFINE_SRCU() and DEFINE_STATIC_SRCU() while avoiding the need to increase the size of the reserved region. Many of the algorithms and some of the code was cheerfully cherry-picked from other code making use of linker sections, perhaps most notably from tracepoints. All bugs are nevertheless the sole property of the author. Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> [ paulmck: Use __section() and use "default" in srcu_module_notify()'s "switch" statement as suggested by Joel Fernandes. ] Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> Tested-by: Joel Fernandes (Google) <joel@joelfernandes.org>