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2017-03-12module: fix memory leak on early load_module() failuresLuis R. Rodriguez
commit a5544880aff90baf1bd4443ac7ff65182213ffcd upstream. While looking for early possible module loading failures I was able to reproduce a memory leak possible with kmemleak. There are a few rare ways to trigger a failure: o we've run into a failure while processing kernel parameters (parse_args() returns an error) o mod_sysfs_setup() fails o we're a live patch module and copy_module_elf() fails Chances of running into this issue is really low. kmemleak splat: unreferenced object 0xffff9f2c4ada1b00 (size 32): comm "kworker/u16:4", pid 82, jiffies 4294897636 (age 681.816s) hex dump (first 32 bytes): 6d 65 6d 73 74 69 63 6b 30 00 00 00 00 00 00 00 memstick0....... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff8c6cfeba>] kmemleak_alloc+0x4a/0xa0 [<ffffffff8c200046>] __kmalloc_track_caller+0x126/0x230 [<ffffffff8c1bc581>] kstrdup+0x31/0x60 [<ffffffff8c1bc5d4>] kstrdup_const+0x24/0x30 [<ffffffff8c3c23aa>] kvasprintf_const+0x7a/0x90 [<ffffffff8c3b5481>] kobject_set_name_vargs+0x21/0x90 [<ffffffff8c4fbdd7>] dev_set_name+0x47/0x50 [<ffffffffc07819e5>] memstick_check+0x95/0x33c [memstick] [<ffffffff8c09c893>] process_one_work+0x1f3/0x4b0 [<ffffffff8c09cb98>] worker_thread+0x48/0x4e0 [<ffffffff8c0a2b79>] kthread+0xc9/0xe0 [<ffffffff8c6dab5f>] ret_from_fork+0x1f/0x40 [<ffffffffffffffff>] 0xffffffffffffffff Fixes: e180a6b7759a ("param: fix charp parameters set via sysfs") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Reviewed-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Jessica Yu <jeyu@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-03modversions: treat symbol CRCs as 32 bit quantitiesArd Biesheuvel
The modversion symbol CRCs are emitted as ELF symbols, which allows us to easily populate the kcrctab sections by relying on the linker to associate each kcrctab slot with the correct value. This has a couple of downsides: - Given that the CRCs are treated as memory addresses, we waste 4 bytes for each CRC on 64 bit architectures, - On architectures that support runtime relocation, a R_<arch>_RELATIVE relocation entry is emitted for each CRC value, which identifies it as a quantity that requires fixing up based on the actual runtime load offset of the kernel. This results in corrupted CRCs unless we explicitly undo the fixup (and this is currently being handled in the core module code) - Such runtime relocation entries take up 24 bytes of __init space each, resulting in a x8 overhead in [uncompressed] kernel size for CRCs. Switching to explicit 32 bit values on 64 bit architectures fixes most of these issues, given that 32 bit values are not treated as quantities that require fixing up based on the actual runtime load offset. Note that on some ELF64 architectures [such as PPC64], these 32-bit values are still emitted as [absolute] runtime relocatable quantities, even if the value resolves to a build time constant. Since relative relocations are always resolved at build time, this patch enables MODULE_REL_CRCS on powerpc when CONFIG_RELOCATABLE=y, which turns the absolute CRC references into relative references into .rodata where the actual CRC value is stored. So redefine all CRC fields and variables as u32, and redefine the __CRC_SYMBOL() macro for 64 bit builds to emit the CRC reference using inline assembler (which is necessary since 64-bit C code cannot use 32-bit types to hold memory addresses, even if they are ultimately resolved using values that do not exceed 0xffffffff). To avoid potential problems with legacy 32-bit architectures using legacy toolchains, the equivalent C definition of the kcrctab entry is retained for 32-bit architectures. Note that this mostly reverts commit d4703aefdbc8 ("module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y") Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-17taint/module: Fix problems when out-of-kernel driver defines true or falseLarry Finger
Commit 7fd8329ba502 ("taint/module: Clean up global and module taint flags handling") used the key words true and false as character members of a new struct. These names cause problems when out-of-kernel modules such as VirtualBox include their own definitions of true and false. Fixes: 7fd8329ba502 ("taint/module: Clean up global and module taint flags handling") Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: Petr Mladek <pmladek@suse.com> Cc: Jessica Yu <jeyu@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jessica Yu <jeyu@redhat.com>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-14Merge tag 'modules-for-v4.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull modules updates from Jessica Yu: "Summary of modules changes for the 4.10 merge window: - The rodata= cmdline parameter has been extended to additionally apply to module mappings - Fix a hard to hit race between module loader error/clean up handling and ftrace registration - Some code cleanups, notably panic.c and modules code use a unified taint_flags table now. This is much cleaner than duplicating the taint flag code in modules.c" * tag 'modules-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: module: fix DEBUG_SET_MODULE_RONX typo module: extend 'rodata=off' boot cmdline parameter to module mappings module: Fix a comment above strong_try_module_get() module: When modifying a module's text ignore modules which are going away too module: Ensure a module's state is set accordingly during module coming cleanup code module: remove trailing whitespace taint/module: Clean up global and module taint flags handling modpost: free allocated memory
2016-11-29Re-enable CONFIG_MODVERSIONS in a slightly weaker formLinus Torvalds
This enables CONFIG_MODVERSIONS again, but allows for missing symbol CRC information in order to work around the issue that newer binutils versions seem to occasionally drop the CRC on the floor. binutils 2.26 seems to work fine, while binutils 2.27 seems to break MODVERSIONS of symbols that have been defined in assembler files. [ We've had random missing CRC's before - it may be an old problem that just is now reliably triggered with the weak asm symbols and a new version of binutils ] Some day I really do want to remove MODVERSIONS entirely. Sadly, today does not appear to be that day: Debian people apparently do want the option to enable MODVERSIONS to make it easier to have external modules across kernel versions, and this seems to be a fairly minimal fix for the annoying problem. Cc: Ben Hutchings <ben@decadent.org.uk> Acked-by: Michal Marek <mmarek@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-27module: extend 'rodata=off' boot cmdline parameter to module mappingsAKASHI Takahiro
The current "rodata=off" parameter disables read-only kernel mappings under CONFIG_DEBUG_RODATA: commit d2aa1acad22f ("mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings") This patch is a logical extension to module mappings ie. read-only mappings at module loading can be disabled even if CONFIG_DEBUG_SET_MODULE_RONX (mainly for debug use). Please note, however, that it only affects RO/RW permissions, keeping NX set. This is the first step to make CONFIG_DEBUG_SET_MODULE_RONX mandatory (always-on) in the future as CONFIG_DEBUG_RODATA on x86 and arm64. Suggested-by: and Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Link: http://lkml.kernel.org/r/20161114061505.15238-1-takahiro.akashi@linaro.org Signed-off-by: Jessica Yu <jeyu@redhat.com>
2016-11-26module: Fix a comment above strong_try_module_get()Miroslav Benes
The comment above strong_try_module_get() function is not true anymore. Return values changed with commit c9a3ba55bb5d ("module: wait for dependent modules doing init."). Signed-off-by: Miroslav Benes <mbenes@suse.cz> Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1611161635330.12580@pobox.suse.cz [jeyu@redhat.com: style fixes to make checkpatch.pl happy] Signed-off-by: Jessica Yu <jeyu@redhat.com>
2016-11-26module: When modifying a module's text ignore modules which are going away tooAaron Tomlin
By default, during the access permission modification of a module's core and init pages, we only ignore modules that are malformed. Albeit for a module which is going away, it does not make sense to change its text to RO since the module should be RW, before deallocation. This patch makes set_all_modules_text_ro() skip modules which are going away too. Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Link: http://lkml.kernel.org/r/1477560966-781-1-git-send-email-atomlin@redhat.com [jeyu@redhat.com: add comment as suggested by Steven Rostedt] Signed-off-by: Jessica Yu <jeyu@redhat.com>
2016-11-26module: Ensure a module's state is set accordingly during module coming ↵Aaron Tomlin
cleanup code In load_module() in the event of an error, for e.g. unknown module parameter(s) specified we go to perform some module coming clean up operations. At this point the module is still in a "formed" state when it is actually going away. This patch updates the module's state accordingly to ensure anyone on the module_notify_list waiting for a module going away notification will be notified accordingly. Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: http://lkml.kernel.org/r/1476980293-19062-2-git-send-email-atomlin@redhat.com Signed-off-by: Jessica Yu <jeyu@redhat.com>
2016-11-26taint/module: Clean up global and module taint flags handlingPetr Mladek
The commit 66cc69e34e86a231 ("Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULE") updated module_taint_flags() to potentially print one more character. But it did not increase the size of the corresponding buffers in m_show() and print_modules(). We have recently done the same mistake when adding a taint flag for livepatching, see https://lkml.kernel.org/r/cfba2c823bb984690b73572aaae1db596b54a082.1472137475.git.jpoimboe@redhat.com Also struct module uses an incompatible type for mod-taints flags. It survived from the commit 2bc2d61a9638dab670d ("[PATCH] list module taint flags in Oops/panic"). There was used "int" for the global taint flags at these times. But only the global tain flags was later changed to "unsigned long" by the commit 25ddbb18aae33ad2 ("Make the taint flags reliable"). This patch defines TAINT_FLAGS_COUNT that can be used to create arrays and buffers of the right size. Note that we could not use enum because the taint flag indexes are used also in assembly code. Then it reworks the table that describes the taint flags. The TAINT_* numbers can be used as the index. Instead, we add information if the taint flag is also shown per-module. Finally, it uses "unsigned long", bit operations, and the updated taint_flags table also for mod->taints. It is not optimal because only few taint flags can be printed by module_taint_flags(). But better be on the safe side. IMHO, it is not worth the optimization and this is a good compromise. Signed-off-by: Petr Mladek <pmladek@suse.com> Link: http://lkml.kernel.org/r/1474458442-21581-1-git-send-email-pmladek@suse.com [jeyu@redhat.com: fix broken lkml link in changelog] Signed-off-by: Jessica Yu <jeyu@redhat.com>
2016-08-26livepatch/module: make TAINT_LIVEPATCH module-specificJosh Poimboeuf
There's no reliable way to determine which module tainted the kernel with TAINT_LIVEPATCH. For example, /sys/module/<klp module>/taint doesn't report it. Neither does the "mod -t" command in the crash tool. Make it crystal clear who the guilty party is by associating TAINT_LIVEPATCH with any module which sets the "livepatch" modinfo attribute. The flag will still get set in the kernel like before, but now it also sets the same flag in mod->taint. Note that now the taint flag gets set when the module is loaded rather than when it's enabled. I also renamed find_livepatch_modinfo() to check_modinfo_livepatch() to better reflect its purpose: it's basically a livepatch-specific sub-function of check_modinfo(). Reported-by: Chunyu Hu <chuhu@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Jessica Yu <jeyu@redhat.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-08-04Merge 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 only interesting thing here is Jessica's patch to add ro_after_init support to modules. The rest are all trivia" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: extable.h: add stddef.h so "NULL" definition is not implicit modules: add ro_after_init support jump_label: disable preemption around __module_text_address(). exceptions: fork exception table content from module.h into extable.h modules: Add kernel parameter to blacklist modules module: Do a WARN_ON_ONCE() for assert module mutex not held Documentation/module-signing.txt: Note need for version info if reusing a key module: Invalidate signatures on force-loaded modules module: Issue warnings when tainting kernel module: fix redundant test. module: fix noreturn attribute for __module_put_and_exit()
2016-08-04modules: add ro_after_init supportJessica Yu
Add ro_after_init support for modules by adding a new page-aligned section in the module layout (after rodata) for ro_after_init data and enabling RO protection for that section after module init runs. Signed-off-by: Jessica Yu <jeyu@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-08-04modules: Add kernel parameter to blacklist modulesPrarit Bhargava
Blacklisting a module in linux has long been a problem. The current procedure is to use rd.blacklist=module_name, however, that doesn't cover the case after the initramfs and before a boot prompt (where one is supposed to use /etc/modprobe.d/blacklist.conf to blacklist runtime loading). Using rd.shell to get an early prompt is hit-or-miss, and doesn't cover all situations AFAICT. This patch adds this functionality of permanently blacklisting a module by its name via the kernel parameter module_blacklist=module_name. [v2]: Rusty, use core_param() instead of __setup() which simplifies things. [v3]: Rusty, undo wreckage from strsep() [v4]: Rusty, simpler version of blacklisted() Signed-off-by: Prarit Bhargava <prarit@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: linux-doc@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-08-04module: Do a WARN_ON_ONCE() for assert module mutex not heldSteven Rostedt
When running with lockdep enabled, I triggered the WARN_ON() in the module code that asserts when module_mutex or rcu_read_lock_sched are not held. The issue I have is that this can also be called from the dump_stack() code, causing us to enter an infinite loop... ------------[ cut here ]------------ WARNING: CPU: 1 PID: 0 at kernel/module.c:268 module_assert_mutex_or_preempt+0x3c/0x3e Modules linked in: ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.7.0-rc3-test-00013-g501c2375253c #14 Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014 ffff880215e8fa70 ffff880215e8fa70 ffffffff812fc8e3 0000000000000000 ffffffff81d3e55b ffff880215e8fac0 ffffffff8104fc88 ffffffff8104fcab 0000000915e88300 0000000000000046 ffffffffa019b29a 0000000000000001 Call Trace: [<ffffffff812fc8e3>] dump_stack+0x67/0x90 [<ffffffff8104fc88>] __warn+0xcb/0xe9 [<ffffffff8104fcab>] ? warn_slowpath_null+0x5/0x1f ------------[ cut here ]------------ WARNING: CPU: 1 PID: 0 at kernel/module.c:268 module_assert_mutex_or_preempt+0x3c/0x3e Modules linked in: ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.7.0-rc3-test-00013-g501c2375253c #14 Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014 ffff880215e8f7a0 ffff880215e8f7a0 ffffffff812fc8e3 0000000000000000 ffffffff81d3e55b ffff880215e8f7f0 ffffffff8104fc88 ffffffff8104fcab 0000000915e88300 0000000000000046 ffffffffa019b29a 0000000000000001 Call Trace: [<ffffffff812fc8e3>] dump_stack+0x67/0x90 [<ffffffff8104fc88>] __warn+0xcb/0xe9 [<ffffffff8104fcab>] ? warn_slowpath_null+0x5/0x1f ------------[ cut here ]------------ WARNING: CPU: 1 PID: 0 at kernel/module.c:268 module_assert_mutex_or_preempt+0x3c/0x3e Modules linked in: ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.7.0-rc3-test-00013-g501c2375253c #14 Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014 ffff880215e8f4d0 ffff880215e8f4d0 ffffffff812fc8e3 0000000000000000 ffffffff81d3e55b ffff880215e8f520 ffffffff8104fc88 ffffffff8104fcab 0000000915e88300 0000000000000046 ffffffffa019b29a 0000000000000001 Call Trace: [<ffffffff812fc8e3>] dump_stack+0x67/0x90 [<ffffffff8104fc88>] __warn+0xcb/0xe9 [<ffffffff8104fcab>] ? warn_slowpath_null+0x5/0x1f ------------[ cut here ]------------ WARNING: CPU: 1 PID: 0 at kernel/module.c:268 module_assert_mutex_or_preempt+0x3c/0x3e [...] Which gives us rather useless information. Worse yet, there's some race that causes this, and I seldom trigger it, so I have no idea what happened. This would not be an issue if that warning was a WARN_ON_ONCE(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-08-02dynamic_debug: only add header when usedLuis de Bethencourt
kernel.h header doesn't directly use dynamic debug, instead we can include it in module.c (which used it via kernel.h). printk.h only uses it if CONFIG_DYNAMIC_DEBUG is on, changing the inclusion to only happen in that case. Link: http://lkml.kernel.org/r/1468429793-16917-1-git-send-email-luisbg@osg.samsung.com [luisbg@osg.samsung.com: include dynamic_debug.h in drb_int.h] Link: http://lkml.kernel.org/r/1468447828-18558-2-git-send-email-luisbg@osg.samsung.com Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27module: Invalidate signatures on force-loaded modulesBen Hutchings
Signing a module should only make it trusted by the specific kernel it was built for, not anything else. Loading a signed module meant for a kernel with a different ABI could have interesting effects. Therefore, treat all signatures as invalid when a module is force-loaded. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: stable@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-07-27module: Issue warnings when tainting kernelLibor Pechacek
While most of the locations where a kernel taint bit is set are accompanied with a warning message, there are two which set their bits silently. If the tainting module gets unloaded later on, it is almost impossible to tell what was the reason for setting the flag. Signed-off-by: Libor Pechacek <lpechacek@suse.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-07-27module: fix redundant test.Rusty Russell
[linux-4.5-rc4/kernel/module.c:1692]: (style) Redundant condition: attr.test. '!attr.test || (attr.test && attr.test(mod))' is equivalent to '!attr.test || attr.test(mod)' This code was added like this ten years ago, in c988d2b284549 "modules: add version and srcversion to sysfs". Reported-by: David Binderman <dcb314@hotmail.com> Cc: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-07-27module: fix noreturn attribute for __module_put_and_exit()Jiri Kosina
__module_put_and_exit() is makred noreturn in module.h declaration, but is lacking the attribute in the definition, which makes some tools (such as sparse) unhappy. Amend the definition with the attribute as well (and reformat the declaration so that it uses more common format). Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-04-01module: preserve Elf information for livepatch modulesJessica Yu
For livepatch modules, copy Elf section, symbol, and string information from the load_info struct in the module loader. Persist copies of the original symbol table and string table. Livepatch manages its own relocation sections in order to reuse module loader code to write relocations. Livepatch modules must preserve Elf information such as section indices in order to apply livepatch relocation sections using the module loader's apply_relocate_add() function. In order to apply livepatch relocation sections, livepatch modules must keep a complete copy of their original symbol table in memory. Normally, a stripped down copy of a module's symbol table (containing only "core" symbols) is made available through module->core_symtab. But for livepatch modules, the symbol table copied into memory on module load must be exactly the same as the symbol table produced when the patch module was compiled. This is because the relocations in each livepatch relocation section refer to their respective symbols with their symbol indices, and the original symbol indices (and thus the symtab ordering) must be preserved in order for apply_relocate_add() to find the right symbol. Signed-off-by: Jessica Yu <jeyu@redhat.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-03-17Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching Pull livepatching update from Jiri Kosina: - cleanup of module notifiers; this depends on a module.c cleanup which has been acked by Rusty; from Jessica Yu - small assorted fixes and MAINTAINERS update * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch/module: remove livepatch module notifier modules: split part of complete_formation() into prepare_coming_module() livepatch: Update maintainers livepatch: Fix the error message about unresolvable ambiguity klp: remove CONFIG_LIVEPATCH dependency from klp headers klp: remove superfluous errors in asm/livepatch.h
2016-03-17Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security layer updates from James Morris: "There are a bunch of fixes to the TPM, IMA, and Keys code, with minor fixes scattered across the subsystem. IMA now requires signed policy, and that policy is also now measured and appraised" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (67 commits) X.509: Make algo identifiers text instead of enum akcipher: Move the RSA DER encoding check to the crypto layer crypto: Add hash param to pkcs1pad sign-file: fix build with CMS support disabled MAINTAINERS: update tpmdd urls MODSIGN: linux/string.h should be #included to get memcpy() certs: Fix misaligned data in extra certificate list X.509: Handle midnight alternative notation in GeneralizedTime X.509: Support leap seconds Handle ISO 8601 leap seconds and encodings of midnight in mktime64() X.509: Fix leap year handling again PKCS#7: fix unitialized boolean 'want' firmware: change kernel read fail to dev_dbg() KEYS: Use the symbol value for list size, updated by scripts/insert-sys-cert KEYS: Reserve an extra certificate symbol for inserting without recompiling modsign: hide openssl output in silent builds tpm_tis: fix build warning with tpm_tis_resume ima: require signed IMA policy ima: measure and appraise the IMA policy itself ima: load policy using path ...
2016-03-17livepatch/module: remove livepatch module notifierJessica Yu
Remove the livepatch module notifier in favor of directly enabling and disabling patches to modules in the module loader. Hard-coding the function calls ensures that ftrace_module_enable() is run before klp_module_coming() during module load, and that klp_module_going() is run before ftrace_release_mod() during module unload. This way, ftrace and livepatch code is run in the correct order during the module load/unload sequence without dependence on the module notifier call chain. Signed-off-by: Jessica Yu <jeyu@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-03-17modules: split part of complete_formation() into prepare_coming_module()Jessica Yu
Put all actions in complete_formation() that are performed after module->state is set to MODULE_STATE_COMING into a separate function prepare_coming_module(). This split prepares for the removal of the livepatch module notifiers in favor of hard-coding function calls to klp_module_{coming,going} in the module loader. The complete_formation -> prepare_coming_module split will also make error handling easier since we can jump to the appropriate error label to do any module GOING cleanup after all the COMING-actions have completed. Signed-off-by: Jessica Yu <jeyu@redhat.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.cz> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-02-21module: replace copy_module_from_fd with kernel versionMimi Zohar
Replace copy_module_from_fd() with kernel_read_file_from_fd(). Although none of the upstreamed LSMs define a kernel_module_from_file hook, IMA is called, based on policy, to prevent unsigned kernel modules from being loaded by the original kernel module syscall and to measure/appraise signed kernel modules. The security function security_kernel_module_from_file() was called prior to reading a kernel module. Preventing unsigned kernel modules from being loaded by the original kernel module syscall remains on the pre-read kernel_read_file() security hook. Instead of reading the kernel module twice, once for measuring/appraising and again for loading the kernel module, the signature validation is moved to the kernel_post_read_file() security hook. This patch removes the security_kernel_module_from_file() hook and security call. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au>
2016-02-18Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching Pull livepatching fixes from Jiri Kosina: - regression (from 4.4) fix for ordering issue, introduced by an earlier ftrace change, that broke live patching of modules. The fix replaces the ftrace module notifier by direct call in order to make the ordering guaranteed and well-defined. The patch, from Jessica Yu, has been acked both by Steven and Rusty - error message fix from Miroslav Benes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: ftrace/module: remove ftrace module notifier livepatch: change the error message in asm/livepatch.h header files
2016-02-17ftrace/module: remove ftrace module notifierJessica Yu
Remove the ftrace module notifier in favor of directly calling ftrace_module_enable() and ftrace_release_mod() in the module loader. Hard-coding the function calls directly in the module loader removes dependence on the module notifier call chain and provides better visibility and control over what gets called when, which is important to kernel utilities such as livepatch. This fixes a notifier ordering issue in which the ftrace module notifier (and hence ftrace_module_enable()) for coming modules was being called after klp_module_notify(), which caused livepatch modules to initialize incorrectly. This patch removes dependence on the module notifier call chain in favor of hard coding the corresponding function calls in the module loader. This ensures that ftrace and livepatch code get called in the correct order on patch module load and unload. Fixes: 5156dca34a3e ("ftrace: Fix the race between ftrace and insmod") Signed-off-by: Jessica Yu <jeyu@redhat.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Petr Mladek <pmladek@suse.cz> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-02-03modules: fix longstanding /proc/kallsyms vs module insertion race.Rusty Russell
For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03module: wrapper for symbol name.Rusty Russell
This trivial wrapper adds clarity and makes the following patch smaller. Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03modules: fix modparam async_probe requestLuis R. Rodriguez
Commit f2411da746985 ("driver-core: add driver module asynchronous probe support") added async probe support, in two forms: * in-kernel driver specification annotation * generic async_probe module parameter (modprobe foo async_probe) To support the generic kernel parameter parse_args() was extended via commit ecc8617053e0 ("module: add extra argument for parse_params() callback") however commit failed to f2411da746985 failed to add the required argument. This causes a crash then whenever async_probe generic module parameter is used. This was overlooked when the form in which in-kernel async probe support was reworked a bit... Fix this as originally intended. Cc: Hannes Reinecke <hare@suse.de> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: stable@vger.kernel.org (4.2+) Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> [minimized]
2016-01-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching Pull livepatching updates from Jiri Kosina: - RO/NX attribute fixes for patch module relocations from Josh Poimboeuf. As part of this effort, module.c has been cleaned up as well and livepatching is piggy-backing on this cleanup. Rusty is OK with this whole lot going through livepatching tree. - symbol disambiguation support from Chris J Arges. That series is also Reviewed-by: Miroslav Benes <mbenes@suse.cz> but this came in only after I've alredy pushed out. Didn't want to rebase because of that, hence I am mentioning it here. - symbol lookup fix from Miroslav Benes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch: Cleanup module page permission changes module: keep percpu symbols in module's symtab module: clean up RO/NX handling. module: use a structure to encapsulate layout. gcov: use within_module() helper. module: Use the same logic for setting and unsetting RO/NX livepatch: function,sympos scheme in livepatch sysfs directory livepatch: add sympos as disambiguator field to klp_reloc livepatch: add old_sympos as disambiguator field to klp_func
2016-01-07ftrace/module: Call clean up function when module init fails earlySteven Rostedt (Red Hat)
If the module init code fails after calling ftrace_module_init() and before calling do_init_module(), we can suffer from a memory leak. This is because ftrace_module_init() allocates pages to store the locations that ftrace hooks are placed in the module text. If do_init_module() fails, it still calls the MODULE_GOING notifiers which will tell ftrace to do a clean up of the pages it allocated for the module. But if load_module() fails before then, the pages allocated by ftrace_module_init() will never be freed. Call ftrace_release_mod() on the module if load_module() fails before getting to do_init_module(). Link: http://lkml.kernel.org/r/567CEA31.1070507@intel.com Reported-by: "Qiu, PeiyangX" <peiyangx.qiu@intel.com> Fixes: a949ae560a511 "ftrace/module: Hardcode ftrace_module_init() call into load_module()" Cc: stable@vger.kernel.org # v2.6.38+ Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-04module: keep percpu symbols in module's symtabMiroslav Benes
Currently, percpu symbols from .data..percpu ELF section of a module are not copied over and stored in final symtab array of struct module. Consequently such symbol cannot be returned via kallsyms API (for example kallsyms_lookup_name). This can be especially confusing when the percpu symbol is exported. Only its __ksymtab et al. are present in its symtab. The culprit is in layout_and_allocate() function where SHF_ALLOC flag is dropped for .data..percpu section. There is in fact no need to copy the section to final struct module, because kernel module loader allocates extra percpu section by itself. Unfortunately only symbols from SHF_ALLOC sections are copied due to a check in is_core_symbol(). The patch changes is_core_symbol() function to copy over also percpu symbols (their st_shndx points to .data..percpu ELF section). We do it only if CONFIG_KALLSYMS_ALL is set to be consistent with the rest of the function (ELF section is SHF_ALLOC but !SHF_EXECINSTR). Finally elf_type() returns type 'a' for a percpu symbol because its address is absolute. Signed-off-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-12-04module: clean up RO/NX handling.Rusty Russell
Modules have three sections: text, rodata and writable data. The code handled the case where these overlapped, however they never can: debug_align() ensures they are always page-aligned. This is why we got away with manually traversing the pages in set_all_modules_text_rw() without rounding. We create three helper functions: frob_text(), frob_rodata() and frob_writable_data(). We then call these explicitly at every point, so it's clear what we're doing. We also expose module_enable_ro() and module_disable_ro() for livepatch to use. Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-12-04module: use a structure to encapsulate layout.Rusty Russell
Makes it easier to handle init vs core cleanly, though the change is fairly invasive across random architectures. It simplifies the rbtree code immediately, however, while keeping the core data together in the same cachline (now iff the rbtree code is enabled). Acked-by: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-12-04module: Use the same logic for setting and unsetting RO/NXJosh Poimboeuf
When setting a module's RO and NX permissions, set_section_ro_nx() is used, but when clearing them, unset_module_{init,core}_ro_nx() are used. The unset functions don't have the same checks the set function has for partial page protections. It's probably harmless, but it's still confusingly asymmetrical. Instead, use the same logic to do both. Also add some new set_module_{init,core}_ro_nx() helper functions for more symmetry with the unset functions. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-08-24module: Fix locking in symbol_put_addr()Peter Zijlstra
Poma (on the way to another bug) reported an assertion triggering: [<ffffffff81150529>] module_assert_mutex_or_preempt+0x49/0x90 [<ffffffff81150822>] __module_address+0x32/0x150 [<ffffffff81150956>] __module_text_address+0x16/0x70 [<ffffffff81150f19>] symbol_put_addr+0x29/0x40 [<ffffffffa04b77ad>] dvb_frontend_detach+0x7d/0x90 [dvb_core] Laura Abbott <labbott@redhat.com> produced a patch which lead us to inspect symbol_put_addr(). This function has a comment claiming it doesn't need to disable preemption around the module lookup because it holds a reference to the module it wants to find, which therefore cannot go away. This is wrong (and a false optimization too, preempt_disable() is really rather cheap, and I doubt any of this is on uber critical paths, otherwise it would've retained a pointer to the actual module anyway and avoided the second lookup). While its true that the module cannot go away while we hold a reference on it, the data structure we do the lookup in very much _CAN_ change while we do the lookup. Therefore fix the comment and add the required preempt_disable(). Reported-by: poma <pomidorabelisima@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Fixes: a6e6abd575fc ("module: remove module_text_address()") Cc: stable@kernel.org
2015-07-29module: weaken locking assertion for oops path.Rusty Russell
We don't actually hold the module_mutex when calling find_module_all from module_kallsyms_lookup_name: that's because it's used by the oops code and we don't want to deadlock. However, access to the list read-only is safe if preempt is disabled, so we can weaken the assertion. Keep a strong version for external callers though. Fixes: 0be964be0d45 ("module: Sanitize RCU usage and locking") Reported-by: He Kuang <hekuang@huawei.com> Cc: stable@kernel.org Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-07-09module: Fix load_module() error pathPeter Zijlstra
The load_module() error path frees a module but forgot to take it out of the mod_tree, leaving a dangling entry in the tree, causing havoc. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reported-by: Arthur Marsh <arthur.marsh@internode.on.net> Tested-by: Arthur Marsh <arthur.marsh@internode.on.net> Fixes: 93c2e105f6bc ("module: Optimize __module_address() using a latched RB-tree") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-07-01Merge 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: "Main excitement here is Peter Zijlstra's lockless rbtree optimization to speed module address lookup. He found some abusers of the module lock doing that too. A little bit of parameter work here too; including Dan Streetman's breaking up the big param mutex so writing a parameter can load another module (yeah, really). Unfortunately that broke the usual suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were appended too" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits) modules: only use mod->param_lock if CONFIG_MODULES param: fix module param locks when !CONFIG_SYSFS. rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() module: add per-module param_lock module: make perm const params: suppress unused variable error, warn once just in case code changes. modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. kernel/module.c: avoid ifdefs for sig_enforce declaration kernel/workqueue.c: remove ifdefs over wq_power_efficient kernel/params.c: export param_ops_bool_enable_only kernel/params.c: generalize bool_enable_only kernel/module.c: use generic module param operaters for sig_enforce kernel/params: constify struct kernel_param_ops uses sysfs: tightened sysfs permission checks module: Rework module_addr_{min,max} module: Use __module_address() for module_address_lookup() module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING module: Optimize __module_address() using a latched RB-tree rbtree: Implement generic latch_tree seqlock: Introduce raw_read_seqcount_latch() ...
2015-06-28param: fix module param locks when !CONFIG_SYSFS.Rusty Russell
As Dan Streetman points out, the entire point of locking for is to stop sysfs accesses, so they're elided entirely in the !SYSFS case. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-26Merge tag 'driver-core-4.2-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the driver core / firmware changes for 4.2-rc1. A number of small changes all over the place in the driver core, and in the firmware subsystem. Nothing really major, full details in the shortlog. Some of it is a bit of churn, given that the platform driver probing changes was found to not work well, so they were reverted. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (31 commits) Revert "base/platform: Only insert MEM and IO resources" Revert "base/platform: Continue on insert_resource() error" Revert "of/platform: Use platform_device interface" Revert "base/platform: Remove code duplication" firmware: add missing kfree for work on async call fs: sysfs: don't pass count == 0 to bin file readers base:dd - Fix for typo in comment to function driver_deferred_probe_trigger(). base/platform: Remove code duplication of/platform: Use platform_device interface base/platform: Continue on insert_resource() error base/platform: Only insert MEM and IO resources firmware: use const for remaining firmware names firmware: fix possible use after free on name on asynchronous request firmware: check for file truncation on direct firmware loading firmware: fix __getname() missing failure check drivers: of/base: move of_init to driver_init drivers/base: cacheinfo: fix annoying typo when DT nodes are absent sysfs: disambiguate between "error code" and "failure" in comments driver-core: fix build for !CONFIG_MODULES driver-core: make __device_attach() static ...
2015-06-26Merge tag 'trace-v4.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "This patch series contains several clean ups and even a new trace clock "monitonic raw". Also some enhancements to make the ring buffer even faster. But the biggest and most noticeable change is the renaming of the ftrace* files, structures and variables that have to deal with trace events. Over the years I've had several developers tell me about their confusion with what ftrace is compared to events. Technically, "ftrace" is the infrastructure to do the function hooks, which include tracing and also helps with live kernel patching. But the trace events are a separate entity altogether, and the files that affect the trace events should not be named "ftrace". These include: include/trace/ftrace.h -> include/trace/trace_events.h include/linux/ftrace_event.h -> include/linux/trace_events.h Also, functions that are specific for trace events have also been renamed: ftrace_print_*() -> trace_print_*() (un)register_ftrace_event() -> (un)register_trace_event() ftrace_event_name() -> trace_event_name() ftrace_trigger_soft_disabled() -> trace_trigger_soft_disabled() ftrace_define_fields_##call() -> trace_define_fields_##call() ftrace_get_offsets_##call() -> trace_get_offsets_##call() Structures have been renamed: ftrace_event_file -> trace_event_file ftrace_event_{call,class} -> trace_event_{call,class} ftrace_event_buffer -> trace_event_buffer ftrace_subsystem_dir -> trace_subsystem_dir ftrace_event_raw_##call -> trace_event_raw_##call ftrace_event_data_offset_##call-> trace_event_data_offset_##call ftrace_event_type_funcs_##call -> trace_event_type_funcs_##call And a few various variables and flags have also been updated. This has been sitting in linux-next for some time, and I have not heard a single complaint about this rename breaking anything. Mostly because these functions, variables and structures are mostly internal to the tracing system and are seldom (if ever) used by anything external to that" * tag 'trace-v4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) ring_buffer: Allow to exit the ring buffer benchmark immediately ring-buffer-benchmark: Fix the wrong type ring-buffer-benchmark: Fix the wrong param in module_param ring-buffer: Add enum names for the context levels ring-buffer: Remove useless unused tracing_off_permanent() ring-buffer: Give NMIs a chance to lock the reader_lock ring-buffer: Add trace_recursive checks to ring_buffer_write() ring-buffer: Allways do the trace_recursive checks ring-buffer: Move recursive check to per_cpu descriptor ring-buffer: Add unlikelys to make fast path the default tracing: Rename ftrace_get_offsets_##call() to trace_event_get_offsets_##call() tracing: Rename ftrace_define_fields_##call() to trace_event_define_fields_##call() tracing: Rename ftrace_event_type_funcs_##call to trace_event_type_funcs_##call tracing: Rename ftrace_data_offset_##call to trace_event_data_offset_##call tracing: Rename ftrace_raw_##call event structures to trace_event_raw_##call tracing: Rename ftrace_trigger_soft_disabled() to trace_trigger_soft_disabled() tracing: Rename FTRACE_EVENT_FL_* flags to EVENT_FILE_FL_* tracing: Rename struct ftrace_subsystem_dir to trace_subsystem_dir tracing: Rename ftrace_event_name() to trace_event_name() tracing: Rename FTRACE_MAX_EVENT to TRACE_EVENT_TYPE_MAX ...
2015-06-23module: add per-module param_lockDan Streetman
Add a "param_lock" mutex to each module, and update params.c to use the correct built-in or module mutex while locking kernel params. Remove the kparam_block_sysfs_r/w() macros, replace them with direct calls to kernel_param_[un]lock(module). The kernel param code currently uses a single mutex to protect modification of any and all kernel params. While this generally works, there is one specific problem with it; a module callback function cannot safely load another module, i.e. with request_module() or even with indirect calls such as crypto_has_alg(). If the module to be loaded has any of its params configured (e.g. with a /etc/modprobe.d/* config file), then the attempt will result in a deadlock between the first module param callback waiting for modprobe, and modprobe trying to lock the single kernel param mutex to set the new module's param. This fixes that by using per-module mutexes, so that each individual module is protected against concurrent changes in its own kernel params, but is not blocked by changes to other module params. All built-in modules continue to use the built-in mutex, since they will always be loaded at runtime and references (e.g. request_module(), crypto_has_alg()) to them will never cause load-time param changing. This also simplifies the interface used by modules to block sysfs access to their params; while there are currently functions to block and unblock sysfs param access which are split up by read and write and expect a single kernel param to be passed, their actual operation is identical and applies to all params, not just the one passed to them; they simply lock and unlock the global param mutex. They are replaced with direct calls to kernel_param_[un]lock(THIS_MODULE), which locks THIS_MODULE's param_lock, or if the module is built-in, it locks the built-in mutex. Suggested-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-08Merge 4.1-rc7 into driver-core-nextGreg Kroah-Hartman
We want the fixes in this branch as well for testing and merge resolution. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-28kernel/module.c: avoid ifdefs for sig_enforce declarationLuis R. Rodriguez
There's no need to require an ifdef over the declaration of sig_enforce as IS_ENABLED() can be used. While at it, there's no harm in exposing this kernel parameter outside of CONFIG_MODULE_SIG as it'd be a no-op on non module sig kernels. Now, technically we should in theory be able to remove the #ifdef'ery over the declaration of the module parameter as we are also trusting the bool_enable_only code for CONFIG_MODULE_SIG kernels but for now remain paranoid and keep it. With time if no one can put a bullet through bool_enable_only and if there are no technical requirements over not exposing CONFIG_MODULE_SIG_FORCE with the measures in place by bool_enable_only we could remove this last ifdef. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: linux-kernel@vger.kernel.org Cc: cocci@systeme.lip6.fr Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28kernel/params.c: generalize bool_enable_onlyLuis R. Rodriguez
This takes out the bool_enable_only implementation from the module loading code and generalizes it so that others can make use of it. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jani Nikula <jani.nikula@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: linux-kernel@vger.kernel.org Cc: cocci@systeme.lip6.fr Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28kernel/module.c: use generic module param operaters for sig_enforceLuis R. Rodriguez
We're directly checking and modifying sig_enforce when needed instead of using the generic helpers. This prevents us from generalizing this helper so that others can use it. Use indirect helpers to allow us to generalize this code a bit and to make it a bit more clear what this is doing. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jani Nikula <jani.nikula@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: linux-kernel@vger.kernel.org Cc: cocci@systeme.lip6.fr Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>