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2015-05-09module: Call module notifier on failure after complete_formation()Steven Rostedt
The module notifier call chain for MODULE_STATE_COMING was moved up before the parsing of args, into the complete_formation() call. But if the module failed to load after that, the notifier call chain for MODULE_STATE_GOING was never called and that prevented the users of those call chains from cleaning up anything that was allocated. Link: http://lkml.kernel.org/r/554C52B9.9060700@gmail.com Reported-by: Pontus Fuchs <pontus.fuchs@gmail.com> Fixes: 4982223e51e8 "module: set nx before marking module MODULE_STATE_COMING" Cc: stable@vger.kernel.org # 3.16+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-22Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Quentin opened a can of worms by adding extable entry checking to modpost, but most architectures seem fixed now. Thanks to all involved. Last minute rebase because I noticed a "[PATCH]" had snuck into a commit message somehow" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: modpost: don't emit section mismatch warnings for compiler optimizations modpost: expand pattern matching to support substring matches modpost: do not try to match the SHT_NUL section. modpost: fix extable entry size calculation. modpost: fix inverted logic in is_extable_fault_address(). modpost: handle -ffunction-sections modpost: Whitelist .text.fixup and .exception.text params: handle quotes properly for values not of form foo="bar". modpost: document the use of struct section_check. modpost: handle relocations mismatch in __ex_table. scripts: add check_extable.sh script. modpost: mismatch_handler: retrieve tosym information only when needed. modpost: factorize symbol pretty print in get_pretty_name(). modpost: add handler function pointer to sectioncheck. modpost: add .sched.text and .kprobes.text to the TEXT_SECTIONS list. modpost: add strict white-listing when referencing sections. module: do not print allocation-fail warning on bogus user buffer size kernel/module.c: fix typos in message about unused symbols
2015-04-14Merge tag 'trace-v4.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "Some clean ups and small fixes, but the biggest change is the addition of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints. Tracepoints have helper functions for the TP_printk() called __print_symbolic() and __print_flags() that lets a numeric number be displayed as a a human comprehensible text. What is placed in the TP_printk() is also shown in the tracepoint format file such that user space tools like perf and trace-cmd can parse the binary data and express the values too. Unfortunately, the way the TRACE_EVENT() macro works, anything placed in the TP_printk() will be shown pretty much exactly as is. The problem arises when enums are used. That's because unlike macros, enums will not be changed into their values by the C pre-processor. Thus, the enum string is exported to the format file, and this makes it useless for user space tools. The TRACE_DEFINE_ENUM() solves this by converting the enum strings in the TP_printk() format into their number, and that is what is shown to user space. For example, the tracepoint tlb_flush currently has this in its format file: __print_symbolic(REC->reason, { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" }, { TLB_REMOTE_SHOOTDOWN, "remote shootdown" }, { TLB_LOCAL_SHOOTDOWN, "local shootdown" }, { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" }) After adding: TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH); TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN); TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN); TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN); Its format file will contain this: __print_symbolic(REC->reason, { 0, "flush on task switch" }, { 1, "remote shootdown" }, { 2, "local shootdown" }, { 3, "local mm shootdown" })" * tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits) tracing: Add enum_map file to show enums that have been mapped writeback: Export enums used by tracepoint to user space v4l: Export enums used by tracepoints to user space SUNRPC: Export enums in tracepoints to user space mm: tracing: Export enums in tracepoints to user space irq/tracing: Export enums in tracepoints to user space f2fs: Export the enums in the tracepoints to userspace net/9p/tracing: Export enums in tracepoints to userspace x86/tlb/trace: Export enums in used by tlb_flush tracepoint tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM() tracing: Allow for modules to convert their enums to values tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation tracing: Give system name a pointer brcmsmac: Move each system tracepoints to their own header iwlwifi: Move each system tracepoints to their own header mac80211: Move message tracepoints to their own header tracing: Add TRACE_SYSTEM_VAR to xhci-hcd tracing: Add TRACE_SYSTEM_VAR to kvm-s390 tracing: Add TRACE_SYSTEM_VAR to intel-sst ...
2015-04-08Copy the kernel module data from user space in chunksLinus Torvalds
Unlike most (all?) other copies from user space, kernel module loading is almost unlimited in size. So we do a potentially huge "copy_from_user()" when we copy the module data from user space to the kernel buffer, which can be a latency concern when preemption is disabled (or voluntary). Also, because 'copy_from_user()' clears the tail of the kernel buffer on failures, even a *failed* copy can end up wasting a lot of time. Normally neither of these are concerns in real life, but they do trigger when doing stress-testing with trinity. Running in a VM seems to add its own overheadm causing trinity module load testing to even trigger the watchdog. The simple fix is to just chunk up the module loading, so that it never tries to copy insanely big areas in one go. That bounds the latency, and also the amount of (unnecessarily, in this case) cleared memory for the failure case. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-08tracing: Allow for modules to convert their enums to valuesSteven Rostedt (Red Hat)
Update the infrastructure such that modules that declare TRACE_DEFINE_ENUM() will have those enums converted into their values in the tracepoint print fmt strings. Link: http://lkml.kernel.org/r/87vbhjp74q.fsf@rustcorp.com.au Acked-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-03-24module: do not print allocation-fail warning on bogus user buffer sizeKirill A. Shutemov
init_module(2) passes user-specified buffer length directly to vmalloc(). It makes warn_alloc_failed() to print out a lot of info into dmesg if user specified insane size, like -1. Let's silence the warning. It doesn't add much value to -ENOMEM return code. Without the patch the syscall is prohibitive noisy for testing with trinity. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-24kernel/module.c: fix typos in message about unused symbolsYannick Guerrini
Fix typos in pr_warn message about unused symbols Signed-off-by: Yannick Guerrini <yguerrini@tomshardware.fr> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-23lockdep: Fix the module unload key range freeing logicPeter Zijlstra
Module unload calls lockdep_free_key_range(), which removes entries from the data structures. Most of the lockdep code OTOH assumes the data structures are append only; in specific see the comments in add_lock_to_list() and look_up_lock_class(). Clearly this has only worked by accident; make it work proper. The actual scenario to make it go boom would involve the memory freed by the module unlock being re-allocated and re-used for a lock inside of a rcu-sched grace period. This is a very unlikely scenario, still better plug the hole. Use RCU list iteration in all places and ammend the comments. Change lockdep_free_key_range() to issue a sync_sched() between removal from the lists and returning -- which results in the memory being freed. Further ensure the callers are placed correctly and comment the requirements. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Tsyvarev <tsyvarev@ispras.ru> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-12kasan, module, vmalloc: rework shadow allocation for modulesAndrey Ryabinin
Current approach in handling shadow memory for modules is broken. Shadow memory could be freed only after memory shadow corresponds it is no longer used. vfree() called from interrupt context could use memory its freeing to store 'struct llist_node' in it: void vfree(const void *addr) { ... if (unlikely(in_interrupt())) { struct vfree_deferred *p = this_cpu_ptr(&vfree_deferred); if (llist_add((struct llist_node *)addr, &p->list)) schedule_work(&p->wq); Later this list node used in free_work() which actually frees memory. Currently module_memfree() called in interrupt context will free shadow before freeing module's memory which could provoke kernel crash. So shadow memory should be freed after module's memory. However, such deallocation order could race with kasan_module_alloc() in module_alloc(). Free shadow right before releasing vm area. At this point vfree()'d memory is not used anymore and yet not available for other allocations. New VM_KASAN flag used to indicate that vm area has dynamically allocated shadow memory so kasan frees shadow only if it was previously allocated. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-03-06kernel/module.c: Update debug alignment after symtable generationLaura Abbott
When CONFIG_DEBUG_SET_MODULE_RONX is enabled, the sizes of module sections are aligned up so appropriate permissions can be applied. Adjusting for the symbol table may cause them to become unaligned. Make sure to re-align the sizes afterward. Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-02-17kernel/module.c: do not inline do_init_module()Jan Kiszka
This provides a reliable breakpoint target, required for automatic symbol loading via the gdb helper command 'lx-symbols'. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13kasan: enable instrumentation of global variablesAndrey Ryabinin
This feature let us to detect accesses out of bounds of global variables. This will work as for globals in kernel image, so for globals in modules. Currently this won't work for symbols in user-specified sections (e.g. __init, __read_mostly, ...) The idea of this is simple. Compiler increases each global variable by redzone size and add constructors invoking __asan_register_globals() function. Information about global variable (address, size, size with redzone ...) passed to __asan_register_globals() so we could poison variable's redzone. This patch also forces module_alloc() to return 8*PAGE_SIZE aligned address making shadow memory handling ( kasan_module_alloc()/kasan_module_free() ) more simple. Such alignment guarantees that each shadow page backing modules address space correspond to only one module_alloc() allocation. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11module: Replace over-engineered nested sleepPeter Zijlstra
Since the introduction of the nested sleep warning; we've established that the occasional sleep inside a wait_event() is fine. wait_event() loops are invariant wrt. spurious wakeups, and the occasional sleep has a similar effect on them. As long as its occasional its harmless. Therefore replace the 'correct' but verbose wait_woken() thing with a simple annotation to shut up the warning. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-02-11module: Annotate nested sleep in resolve_symbol()Peter Zijlstra
Because wait_event() loops are safe vs spurious wakeups we can allow the occasional sleep -- which ends up being very similar. Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-02-06module: Remove double spaces in module verification taint messageMarcel Holtmann
The warning message when loading modules with a wrong signature has two spaces in it: "module verification failed: signature and/or required key missing" Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-02-06kernel/module.c: Free lock-classes if parse_args failedAndrey Tsyvarev
parse_args call module parameters' .set handlers, which may use locks defined in the module. So, these classes should be freed in case parse_args returns error(e.g. due to incorrect parameter passed). Signed-off-by: Andrey Tsyvarev <tsyvarev@ispras.ru> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-22module: make module_refcount() a signed integer.Rusty Russell
James Bottomley points out that it will be -1 during unload. It's only used for diagnostics, so let's not hide that as it could be a clue as to what's gone wrong. Cc: Jason Wessel <jason.wessel@windriver.com> Acked-and-documention-added-by: James Bottomley <James.Bottomley@HansenPartnership.com> Reviewed-by: Masami Hiramatsu <maasami.hiramatsu.pt@hitachi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-20module: fix race in kallsyms resolution during module load success.Rusty Russell
The kallsyms routines (module_symbol_name, lookup_module_* etc) disable preemption to walk the modules rather than taking the module_mutex: this is because they are used for symbol resolution during oopses. This works because there are synchronize_sched() and synchronize_rcu() in the unload and failure paths. However, there's one case which doesn't have that: the normal case where module loading succeeds, and we free the init section. We don't want a synchronize_rcu() there, because it would slow down module loading: this bug was introduced in 2009 to speed module loading in the first place. Thus, we want to do the free in an RCU callback. We do this in the simplest possible way by allocating a new rcu_head: if we put it in the module structure we'd have to worry about that getting freed. Reported-by: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-20module: remove mod arg from module_free, rename module_memfree().Rusty Russell
Nothing needs the module pointer any more, and the next patch will call it from RCU, where the module itself might no longer exist. Removing the arg is the safest approach. This just codifies the use of the module_alloc/module_free pattern which ftrace and bpf use. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Ley Foon Tan <lftan@altera.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: x86@kernel.org Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: linux-cris-kernel@axis.com Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: nios2-dev@lists.rocketboards.org Cc: linuxppc-dev@lists.ozlabs.org Cc: sparclinux@vger.kernel.org Cc: netdev@vger.kernel.org
2015-01-20module_arch_freeing_init(): new hook for archs before module->module_init freed.Rusty Russell
Archs have been abusing module_free() to clean up their arch-specific allocations. Since module_free() is also (ab)used by BPF and trace code, let's keep it to simple allocations, and provide a hook called before that. This means that avr32, ia64, parisc and s390 no longer need to implement their own module_free() at all. avr32 doesn't need module_finalize() either. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-kernel@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linux-s390@vger.kernel.org
2014-12-18Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "The exciting thing here is the getting rid of stop_machine on module removal. This is possible by using a simple atomic_t for the counter, rather than our fancy per-cpu counter: it turns out that no one is doing a module increment per net packet, so the slowdown should be in the noise" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: param: do not set store func without write perm params: cleanup sysfs allocation kernel:module Fix coding style errors and warnings. module: Remove stop_machine from module unloading module: Replace module_ref with atomic_t refcnt lib/bug: Use RCU list ops for module_bug_list module: Unlink module with RCU synchronizing instead of stop_machine module: Wait for RCU synchronizing before releasing a module
2014-11-11kernel:module Fix coding style errors and warnings.Ionut Alexa
Fixed codin style errors and warnings. Changes printk with print_debug/warn. Changed seq_printf to seq_puts. Signed-off-by: Ionut Alexa <ionut.m.alexa@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (removed bogus KERN_DEFAULT conversion)
2014-11-11module: Remove stop_machine from module unloadingMasami Hiramatsu
Remove stop_machine from module unloading by adding new reference counting algorithm. This atomic refcounter works like a semaphore, it can get (be incremented) only when the counter is not 0. When loading a module, kmodule subsystem sets the counter MODULE_REF_BASE (= 1). And when unloading the module, it subtracts MODULE_REF_BASE from the counter. If no one refers the module, the refcounter becomes 0 and we can remove the module safely. If someone referes it, we try to recover the counter by adding MODULE_REF_BASE unless the counter becomes 0, because the referrer can put the module right before recovering. If the recovering is failed, we can get the 0 refcount and it never be incremented again, it can be removed safely too. Note that __module_get() forcibly gets the module refcounter, users should use try_module_get() instead of that. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-11module: Replace module_ref with atomic_t refcntMasami Hiramatsu
Replace module_ref per-cpu complex reference counter with an atomic_t simple refcnt. This is for code simplification. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-11lib/bug: Use RCU list ops for module_bug_listMasami Hiramatsu
Actually since module_bug_list should be used in BUG context, we may not need this. But for someone who want to use this from normal context, this makes module_bug_list an RCU list. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-11module: Unlink module with RCU synchronizing instead of stop_machineMasami Hiramatsu
Unlink module from module list with RCU synchronizing instead of using stop_machine(). Since module list is already protected by rcu, we don't need stop_machine() anymore. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-11module: Wait for RCU synchronizing before releasing a moduleMasami Hiramatsu
Wait for RCU synchronizing on failure path of module loading before releasing struct module, because the memory of mod->list can still be accessed by list walkers (e.g. kallsyms). Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-10-28sched, modules: Fix nested sleep in add_unformed_module()Peter Zijlstra
This is a genuine bug in add_unformed_module(), we cannot use blocking primitives inside a wait loop. So rewrite the wait_event_interruptible() usage to use the fresh wait_woken() stuff. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: tglx@linutronix.de Cc: ilya.dryomov@inktank.com Cc: umgwanakikbuti@gmail.com Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: oleg@redhat.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: http://lkml.kernel.org/r/20140924082242.458562904@infradead.org [ So this is probably complex to backport and the race wasn't reported AFAIK, so not marked for -stable. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-18Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module fix from Rusty Russell: "A single panic fix for a rare race, stable CC'd" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: modules, lock around setting of MODULE_STATE_UNFORMED
2014-10-15modules, lock around setting of MODULE_STATE_UNFORMEDPrarit Bhargava
A panic was seen in the following sitation. There are two threads running on the system. The first thread is a system monitoring thread that is reading /proc/modules. The second thread is loading and unloading a module (in this example I'm using my simple dummy-module.ko). Note, in the "real world" this occurred with the qlogic driver module. When doing this, the following panic occurred: ------------[ cut here ]------------ kernel BUG at kernel/module.c:3739! invalid opcode: 0000 [#1] SMP Modules linked in: binfmt_misc sg nfsv3 rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache intel_powerclamp coretemp kvm_intel kvm crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel lrw igb gf128mul glue_helper iTCO_wdt iTCO_vendor_support ablk_helper ptp sb_edac cryptd pps_core edac_core shpchp i2c_i801 pcspkr wmi lpc_ich ioatdma mfd_core dca ipmi_si nfsd ipmi_msghandler auth_rpcgss nfs_acl lockd sunrpc xfs libcrc32c sr_mod cdrom sd_mod crc_t10dif crct10dif_common mgag200 syscopyarea sysfillrect sysimgblt i2c_algo_bit drm_kms_helper ttm isci drm libsas ahci libahci scsi_transport_sas libata i2c_core dm_mirror dm_region_hash dm_log dm_mod [last unloaded: dummy_module] CPU: 37 PID: 186343 Comm: cat Tainted: GF O-------------- 3.10.0+ #7 Hardware name: Intel Corporation S2600CP/S2600CP, BIOS RMLSDP.86I.00.29.D696.1311111329 11/11/2013 task: ffff8807fd2d8000 ti: ffff88080fa7c000 task.ti: ffff88080fa7c000 RIP: 0010:[<ffffffff810d64c5>] [<ffffffff810d64c5>] module_flags+0xb5/0xc0 RSP: 0018:ffff88080fa7fe18 EFLAGS: 00010246 RAX: 0000000000000003 RBX: ffffffffa03b5200 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffff88080fa7fe38 RDI: ffffffffa03b5000 RBP: ffff88080fa7fe28 R08: 0000000000000010 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000000000f R12: ffffffffa03b5000 R13: ffffffffa03b5008 R14: ffffffffa03b5200 R15: ffffffffa03b5000 FS: 00007f6ae57ef740(0000) GS:ffff88101e7a0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000404f70 CR3: 0000000ffed48000 CR4: 00000000001407e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffffffffa03b5200 ffff8810101e4800 ffff88080fa7fe70 ffffffff810d666c ffff88081e807300 000000002e0f2fbf 0000000000000000 ffff88100f257b00 ffffffffa03b5008 ffff88080fa7ff48 ffff8810101e4800 ffff88080fa7fee0 Call Trace: [<ffffffff810d666c>] m_show+0x19c/0x1e0 [<ffffffff811e4d7e>] seq_read+0x16e/0x3b0 [<ffffffff812281ed>] proc_reg_read+0x3d/0x80 [<ffffffff811c0f2c>] vfs_read+0x9c/0x170 [<ffffffff811c1a58>] SyS_read+0x58/0xb0 [<ffffffff81605829>] system_call_fastpath+0x16/0x1b Code: 48 63 c2 83 c2 01 c6 04 03 29 48 63 d2 eb d9 0f 1f 80 00 00 00 00 48 63 d2 c6 04 13 2d 41 8b 0c 24 8d 50 02 83 f9 01 75 b2 eb cb <0f> 0b 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 RIP [<ffffffff810d64c5>] module_flags+0xb5/0xc0 RSP <ffff88080fa7fe18> Consider the two processes running on the system. CPU 0 (/proc/modules reader) CPU 1 (loading/unloading module) CPU 0 opens /proc/modules, and starts displaying data for each module by traversing the modules list via fs/seq_file.c:seq_open() and fs/seq_file.c:seq_read(). For each module in the modules list, seq_read does op->start() <-- this is a pointer to m_start() op->show() <- this is a pointer to m_show() op->stop() <-- this is a pointer to m_stop() The m_start(), m_show(), and m_stop() module functions are defined in kernel/module.c. The m_start() and m_stop() functions acquire and release the module_mutex respectively. ie) When reading /proc/modules, the module_mutex is acquired and released for each module. m_show() is called with the module_mutex held. It accesses the module struct data and attempts to write out module data. It is in this code path that the above BUG_ON() warning is encountered, specifically m_show() calls static char *module_flags(struct module *mod, char *buf) { int bx = 0; BUG_ON(mod->state == MODULE_STATE_UNFORMED); ... The other thread, CPU 1, in unloading the module calls the syscall delete_module() defined in kernel/module.c. The module_mutex is acquired for a short time, and then released. free_module() is called without the module_mutex. free_module() then sets mod->state = MODULE_STATE_UNFORMED, also without the module_mutex. Some additional code is called and then the module_mutex is reacquired to remove the module from the modules list: /* Now we can delete it from the lists */ mutex_lock(&module_mutex); stop_machine(__unlink_module, mod, NULL); mutex_unlock(&module_mutex); This is the sequence of events that leads to the panic. CPU 1 is removing dummy_module via delete_module(). It acquires the module_mutex, and then releases it. CPU 1 has NOT set dummy_module->state to MODULE_STATE_UNFORMED yet. CPU 0, which is reading the /proc/modules, acquires the module_mutex and acquires a pointer to the dummy_module which is still in the modules list. CPU 0 calls m_show for dummy_module. The check in m_show() for MODULE_STATE_UNFORMED passed for dummy_module even though it is being torn down. Meanwhile CPU 1, which has been continuing to remove dummy_module without holding the module_mutex, now calls free_module() and sets dummy_module->state to MODULE_STATE_UNFORMED. CPU 0 now calls module_flags() with dummy_module and ... static char *module_flags(struct module *mod, char *buf) { int bx = 0; BUG_ON(mod->state == MODULE_STATE_UNFORMED); and BOOM. Acquire and release the module_mutex lock around the setting of MODULE_STATE_UNFORMED in the teardown path, which should resolve the problem. Testing: In the unpatched kernel I can panic the system within 1 minute by doing while (true) do insmod dummy_module.ko; rmmod dummy_module.ko; done and while (true) do cat /proc/modules; done in separate terminals. In the patched kernel I was able to run just over one hour without seeing any issues. I also verified the output of panic via sysrq-c and the output of /proc/modules looks correct for all three states for the dummy_module. dummy_module 12661 0 - Unloading 0xffffffffa03a5000 (OE-) dummy_module 12661 0 - Live 0xffffffffa03bb000 (OE) dummy_module 14015 1 - Loading 0xffffffffa03a5000 (OE+) Signed-off-by: Prarit Bhargava <prarit@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
2014-10-08Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - eBPF JIT compiler for arm64 - CPU suspend backend for PSCI (firmware interface) with standard idle states defined in DT (generic idle driver to be merged via a different tree) - Support for CONFIG_DEBUG_SET_MODULE_RONX - Support for unmapped cpu-release-addr (outside kernel linear mapping) - set_arch_dma_coherent_ops() implemented and bus notifiers removed - EFI_STUB improvements when base of DRAM is occupied - Typos in KGDB macros - Clean-up to (partially) allow kernel building with LLVM - Other clean-ups (extern keyword, phys_addr_t usage) * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (51 commits) arm64: Remove unneeded extern keyword ARM64: make of_device_ids const arm64: Use phys_addr_t type for physical address aarch64: filter $x from kallsyms arm64: Use DMA_ERROR_CODE to denote failed allocation arm64: Fix typos in KGDB macros arm64: insn: Add return statements after BUG_ON() arm64: debug: don't re-enable debug exceptions on return from el1_dbg Revert "arm64: dmi: Add SMBIOS/DMI support" arm64: Implement set_arch_dma_coherent_ops() to replace bus notifiers of: amba: use of_dma_configure for AMBA devices arm64: dmi: Add SMBIOS/DMI support arm64: Correct ftrace calls to aarch64_insn_gen_branch_imm() arm64:mm: initialize max_mapnr using function set_max_mapnr setup: Move unmask of async interrupts after possible earlycon setup arm64: LLVMLinux: Fix inline arm64 assembly for use with clang arm64: pageattr: Correctly adjust unaligned start addresses net: bpf: arm64: fix module memory leak when JIT image build fails arm64: add PSCI CPU_SUSPEND based cpu_suspend support arm64: kernel: introduce cpu_init_idle CPU operation ...
2014-10-02aarch64: filter $x from kallsymsKyle McMartin
Similar to ARM, AArch64 is generating $x and $d syms... which isn't terribly helpful when looking at %pF output and the like. Filter those out in kallsyms, modpost and when looking at module symbols. Seems simplest since none of these check EM_ARM anyway, to just add it to the strchr used, rather than trying to make things overly complicated. initcall_debug improves: dmesg_before.txt: initcall $x+0x0/0x154 [sg] returned 0 after 26331 usecs dmesg_after.txt: initcall init_sg+0x0/0x154 [sg] returned 0 after 15461 usecs Signed-off-by: Kyle McMartin <kyle@redhat.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-08-27module: rename KERNEL_PARAM_FL_NOARG to avoid confusionJani Nikula
Make it clear this is about kernel_param_ops, not kernel_param (which will soon have a flags field of its own). No functional changes. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jean Delvare <khali@linux-fr.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Jon Mason <jon.mason@intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-16module: Clean up ro/nx after early module load failuresAndy Lutomirski
The commit 4982223e51e8 module: set nx before marking module MODULE_STATE_COMING. introduced a regression: if a module fails to parse its arguments or if mod_sysfs_setup fails, then the module's memory will be freed while still read-only. Anything that reuses that memory will crash as soon as it tries to write to it. Cc: stable@vger.kernel.org # v3.16 Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-10Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "This finally applies the stricter sysfs perms checking we pulled out before last merge window. A few stragglers are fixed (thanks linux-next!)" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: arch/powerpc/platforms/powernv/opal-dump.c: fix world-writable sysfs files arch/powerpc/platforms/powernv/opal-elog.c: fix world-writable sysfs files drivers/video/fbdev/s3c2410fb.c: don't make debug world-writable. ARM: avoid ARM binutils leaking ELF local symbols scripts: modpost: Remove numeric suffix pattern matching scripts: modpost: fix compilation warning sysfs: disallow world-writable files. module: return bool from within_module*() module: add within_module() function modules: Fix build error in moduleloader.h
2014-07-27ARM: avoid ARM binutils leaking ELF local symbolsRussell King
Symbols starting with .L are ELF local symbols and should not appear in ELF symbol tables. However, unfortunately ARM binutils leaks the .LANCHOR symbols into the symbol table, which leads kallsyms to report these symbols rather than the real name. It is not very useful when %pf reports symbols against these leaked .LANCHOR symbols. Arrange for kallsyms to ignore these symbols using the same mechanism that is used for the ARM mapping symbols. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-07-27module: add within_module() functionPetr Mladek
It is just a small optimization that allows to replace few occurrences of within_module_init() || within_module_core() with a single call. Signed-off-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-07-03crypto: fips - only panic on bad/missing crypto mod signaturesJarod Wilson
Per further discussion with NIST, the requirements for FIPS state that we only need to panic the system on failed kernel module signature checks for crypto subsystem modules. This moves the fips-mode-only module signature check out of the generic module loading code, into the crypto subsystem, at points where we can catch both algorithm module loads and mode module loads. At the same time, make CONFIG_CRYPTO_FIPS dependent on CONFIG_MODULE_SIG, as this is entirely necessary for FIPS mode. v2: remove extraneous blank line, perform checks in static inline function, drop no longer necessary fips.h include. CC: "David S. Miller" <davem@davemloft.net> CC: Rusty Russell <rusty@rustcorp.com.au> CC: Stephan Mueller <stephan.mueller@atsec.com> Signed-off-by: Jarod Wilson <jarod@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-06-11Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Most of this is cleaning up various driver sysfs permissions so we can re-add the perm check (we unified the module param and sysfs checks, but the module ones were stronger so we weakened them temporarily). Param parsing gets documented, and also "--" now forces args to be handed to init (and ignored by the kernel). Module NX/RO protections get tightened: we now set them before calling parse_args()" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: module: set nx before marking module MODULE_STATE_COMING. samples/kobject/: avoid world-writable sysfs files. drivers/hid/hid-picolcd_fb: avoid world-writable sysfs files. drivers/staging/speakup/: avoid world-writable sysfs files. drivers/regulator/virtual: avoid world-writable sysfs files. drivers/scsi/pm8001/pm8001_ctl.c: avoid world-writable sysfs files. drivers/hid/hid-lg4ff.c: avoid world-writable sysfs files. drivers/video/fbdev/sm501fb.c: avoid world-writable sysfs files. drivers/mtd/devices/docg3.c: avoid world-writable sysfs files. speakup: fix incorrect perms on speakup_acntsa.c cpumask.h: silence warning with -Wsign-compare Documentation: Update kernel-parameters.tx param: hand arguments after -- straight to init modpost: Fix resource leak in read_dump()
2014-05-14module: set nx before marking module MODULE_STATE_COMING.Rusty Russell
We currently set RO & NX on modules very late: after we move them from MODULE_STATE_UNFORMED to MODULE_STATE_COMING, and after we call parse_args() (which can exec code in the module). Much better is to do it in complete_formation() and then call the notifier. This means that the notifiers will be called on a module which is already RO & NX, so that may cause problems (ftrace already changed so they're unaffected). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-05-01Merge tag 'fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module fixes from Rusty Russell: "Fixed one missing place for the new taint flag, and remove a warning giving only false positives (now we finally figured out why)" * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: module: remove warning about waiting module removal. Fix: tracing: use 'E' instead of 'X' for unsigned module taint flag
2014-04-28ftrace/module: Hardcode ftrace_module_init() call into load_module()Steven Rostedt (Red Hat)
A race exists between module loading and enabling of function tracer. CPU 1 CPU 2 ----- ----- load_module() module->state = MODULE_STATE_COMING register_ftrace_function() mutex_lock(&ftrace_lock); ftrace_startup() update_ftrace_function(); ftrace_arch_code_modify_prepare() set_all_module_text_rw(); <enables-ftrace> ftrace_arch_code_modify_post_process() set_all_module_text_ro(); [ here all module text is set to RO, including the module that is loading!! ] blocking_notifier_call_chain(MODULE_STATE_COMING); ftrace_init_module() [ tries to modify code, but it's RO, and fails! ftrace_bug() is called] When this race happens, ftrace_bug() will produces a nasty warning and all of the function tracing features will be disabled until reboot. The simple solution is to treate module load the same way the core kernel is treated at boot. To hardcode the ftrace function modification of converting calls to mcount into nops. This is done in init/main.c there's no reason it could not be done in load_module(). This gives a better control of the changes and doesn't tie the state of the module to its notifiers as much. Ftrace is special, it needs to be treated as such. The reason this would work, is that the ftrace_module_init() would be called while the module is in MODULE_STATE_UNFORMED, which is ignored by the set_all_module_text_ro() call. Link: http://lkml.kernel.org/r/1395637826-3312-1-git-send-email-indou.takao@jp.fujitsu.com Reported-by: Takao Indoh <indou.takao@jp.fujitsu.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@vger.kernel.org # 2.6.38+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-04-28param: hand arguments after -- straight to initRusty Russell
The kernel passes any args it doesn't need through to init, except it assumes anything containing '.' belongs to the kernel (for a module). This change means all users can clearly distinguish which arguments are for init. For example, the kernel uses debug ("dee-bug") to mean log everything to the console, where systemd uses the debug from the Scandinavian "day-boog" meaning "fail to boot". If a future versions uses argv[] instead of reading /proc/cmdline, this confusion will be avoided. eg: test 'FOO="this is --foo"' -- 'systemd.debug="true true true"' Gives: argv[0] = '/debug-init' argv[1] = 'test' argv[2] = 'systemd.debug=true true true' envp[0] = 'HOME=/' envp[1] = 'TERM=linux' envp[2] = 'FOO=this is --foo' Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-04-28module: remove warning about waiting module removal.Rusty Russell
We remove the waiting module removal in commit 3f2b9c9cdf38 (September 2013), but it turns out that modprobe in kmod (< version 16) was asking for waiting module removal. No one noticed since modprobe would check for 0 usage immediately before trying to remove the module, and the race is unlikely. However, it means that anyone running old (but not ancient) kmod versions is hitting the printk designed to see if anyone was running "rmmod -w". All reports so far have been false positives, so remove the warning. Fixes: 3f2b9c9cdf389e303b2273679af08aab5f153517 Reported-by: Valerio Vanni <valerio.vanni@inwind.it> Cc: Elliott, Robert (Server Storage) <Elliott@hp.com> Cc: stable@kernel.org Acked-by: Lucas De Marchi <lucas.de.marchi@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-04-07modules: use raw_cpu_write for initialization of per cpu refcount.Christoph Lameter
The initialization of a structure is not subject to synchronization. The use of __this_cpu would trigger a false positive with the additional preemption checks for __this_cpu ops. So simply disable the check through the use of raw_cpu ops. Trace: __this_cpu_write operation in preemptible [00000000] code: modprobe/286 caller is __this_cpu_preempt_check+0x38/0x60 CPU: 3 PID: 286 Comm: modprobe Tainted: GF 3.12.0-rc4+ #187 Call Trace: dump_stack+0x4e/0x82 check_preemption_disabled+0xec/0x110 __this_cpu_preempt_check+0x38/0x60 load_module+0xcfd/0x2650 SyS_init_module+0xa6/0xd0 tracesys+0xe1/0xe6 Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-06Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Nothing major: the stricter permissions checking for sysfs broke a staging driver; fix included. Greg KH said he'd take the patch but hadn't as the merge window opened, so it's included here to avoid breaking build" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: staging: fix up speakup kobject mode Use 'E' instead of 'X' for unsigned module taint flag. VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms. kallsyms: fix percpu vars on x86-64 with relocation. kallsyms: generalize address range checking module: LLVMLinux: Remove unused function warning from __param_check macro Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULE module: remove MODULE_GENERIC_TABLE module: allow multiple calls to MODULE_DEVICE_TABLE() per module module: use pr_cont
2014-03-31Merge branch 'x86-asmlinkage-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 LTO changes from Peter Anvin: "More infrastructure work in preparation for link-time optimization (LTO). Most of these changes is to make sure symbols accessed from assembly code are properly marked as visible so the linker doesn't remove them. My understanding is that the changes to support LTO are still not upstream in binutils, but are on the way there. This patchset should conclude the x86-specific changes, and remaining patches to actually enable LTO will be fed through the Kbuild tree (other than keeping up with changes to the x86 code base, of course), although not necessarily in this merge window" * 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits) Kbuild, lto: Handle basic LTO in modpost Kbuild, lto: Disable LTO for asm-offsets.c Kbuild, lto: Add a gcc-ld script to let run gcc as ld Kbuild, lto: add ld-version and ld-ifversion macros Kbuild, lto: Drop .number postfixes in modpost Kbuild, lto, workaround: Don't warn for initcall_reference in modpost lto: Disable LTO for sys_ni lto: Handle LTO common symbols in module loader lto, workaround: Add workaround for initcall reordering lto: Make asmlinkage __visible x86, lto: Disable LTO for the x86 VDSO initconst, x86: Fix initconst mistake in ts5500 code initconst: Fix initconst mistake in dcdbas asmlinkage: Make trace_hardirqs_on/off_caller visible asmlinkage, x86: Fix 32bit memcpy for LTO asmlinkage Make __stack_chk_failed and memcmp visible asmlinkage: Mark rwsem functions that can be called from assembler asmlinkage asmlinkage: Make main_extable_sort_needed visible asmlinkage, mutex: Mark __visible asmlinkage: Make trace_hardirq visible ...
2014-03-31Use 'E' instead of 'X' for unsigned module taint flag.Rusty Russell
Takashi Iwai <tiwai@suse.de> says: > The letter 'X' has been already used for SUSE kernels for very long > time, to indicate the external supported modules. Can the new flag be > changed to another letter for avoiding conflict...? > (BTW, we also use 'N' for "no support", too.) Note: this code should be cleaned up, so we don't have such maps in three places! Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-03-20Rename TAINT_UNSAFE_SMP to TAINT_CPU_OUT_OF_SPECDave Jones
Rename TAINT_UNSAFE_SMP to TAINT_CPU_OUT_OF_SPEC, so we can repurpose the flag to encompass a wider range of pushing the CPU beyond its warrany. Signed-off-by: Dave Jones <davej@fedoraproject.org> Link: http://lkml.kernel.org/r/20140226154949.GA770@redhat.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-03-13Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULEMathieu Desnoyers
Users have reported being unable to trace non-signed modules loaded within a kernel supporting module signature. This is caused by tracepoint.c:tracepoint_module_coming() refusing to take into account tracepoints sitting within force-loaded modules (TAINT_FORCED_MODULE). The reason for this check, in the first place, is that a force-loaded module may have a struct module incompatible with the layout expected by the kernel, and can thus cause a kernel crash upon forced load of that module on a kernel with CONFIG_TRACEPOINTS=y. Tracepoints, however, specifically accept TAINT_OOT_MODULE and TAINT_CRAP, since those modules do not lead to the "very likely system crash" issue cited above for force-loaded modules. With kernels having CONFIG_MODULE_SIG=y (signed modules), a non-signed module is tainted re-using the TAINT_FORCED_MODULE taint flag. Unfortunately, this means that Tracepoints treat that module as a force-loaded module, and thus silently refuse to consider any tracepoint within this module. Since an unsigned module does not fit within the "very likely system crash" category of tainting, add a new TAINT_UNSIGNED_MODULE taint flag to specifically address this taint behavior, and accept those modules within Tracepoints. We use the letter 'X' as a taint flag character for a module being loaded that doesn't know how to sign its name (proposed by Steven Rostedt). Also add the missing 'O' entry to trace event show_module_flags() list for the sake of completeness. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> NAKed-by: Ingo Molnar <mingo@redhat.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: David Howells <dhowells@redhat.com> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>