- 13 1月, 2018 2 次提交
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由 Masami Hiramatsu 提交于
Add injectable error types for each error-injectable function. One motivation of error injection test is to find software flaws, mistakes or mis-handlings of expectable errors. If we find such flaws by the test, that is a program bug, so we need to fix it. But if the tester miss input the error (e.g. just return success code without processing anything), it causes unexpected behavior even if the caller is correctly programmed to handle any errors. That is not what we want to test by error injection. To clarify what type of errors the caller must expect for each injectable function, this introduces injectable error types: - EI_ETYPE_NULL : means the function will return NULL if it fails. No ERR_PTR, just a NULL. - EI_ETYPE_ERRNO : means the function will return -ERRNO if it fails. - EI_ETYPE_ERRNO_NULL : means the function will return -ERRNO (ERR_PTR) or NULL. ALLOW_ERROR_INJECTION() macro is expanded to get one of NULL, ERRNO, ERRNO_NULL to record the error type for each function. e.g. ALLOW_ERROR_INJECTION(open_ctree, ERRNO) This error types are shown in debugfs as below. ==== / # cat /sys/kernel/debug/error_injection/list open_ctree [btrfs] ERRNO io_ctl_init [btrfs] ERRNO ==== Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org> Reviewed-by: NJosef Bacik <jbacik@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Masami Hiramatsu 提交于
Since error-injection framework is not limited to be used by kprobes, nor bpf. Other kernel subsystems can use it freely for checking safeness of error-injection, e.g. livepatch, ftrace etc. So this separate error-injection framework from kprobes. Some differences has been made: - "kprobe" word is removed from any APIs/structures. - BPF_ALLOW_ERROR_INJECTION() is renamed to ALLOW_ERROR_INJECTION() since it is not limited for BPF too. - CONFIG_FUNCTION_ERROR_INJECTION is the config item of this feature. It is automatically enabled if the arch supports error injection feature for kprobe or ftrace etc. Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org> Reviewed-by: NJosef Bacik <jbacik@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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- 13 12月, 2017 1 次提交
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由 Josef Bacik 提交于
Using BPF we can override kprob'ed functions and return arbitrary values. Obviously this can be a bit unsafe, so make this feature opt-in for functions. Simply tag a function with KPROBE_ERROR_INJECT_SYMBOL in order to give BPF access to that function for error injection purposes. Signed-off-by: NJosef Bacik <jbacik@fb.com> Acked-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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- 09 11月, 2017 1 次提交
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由 Bruno E. O. Meneguele 提交于
A static variable sig_enforce is used as status var to indicate the real value of CONFIG_MODULE_SIG_FORCE, once this one is set the var will hold true, but if the CONFIG is not set the status var will hold whatever value is present in the module.sig_enforce kernel cmdline param: true when =1 and false when =0 or not present. Considering this cmdline param take place over the CONFIG value when it's not set, other places in the kernel could misbehave since they would have only the CONFIG_MODULE_SIG_FORCE value to rely on. Exporting this status var allows the kernel to rely in the effective value of module signature enforcement, being it from CONFIG value or cmdline param. Signed-off-by: NBruno E. O. Meneguele <brdeoliv@redhat.com> Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
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- 30 7月, 2017 1 次提交
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由 Matthias Kaehlcke 提交于
MODULE_DEVICE_TABLE(type, name) creates an alias of type 'extern const typeof(name)'. If 'name' is already constant the 'const' attribute is specified twice, which is not allowed in C89 (see discussion at https://lkml.org/lkml/2017/5/23/1440). Since the kernel is built with -std=gnu89 clang generates warnings like this: drivers/thermal/x86_pkg_temp_thermal.c:509:1: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier] MODULE_DEVICE_TABLE(x86cpu, pkg_temp_thermal_ids); ^ ./include/linux/module.h:212:8: note: expanded from macro 'MODULE_DEVICE_TABLE' extern const typeof(name) __mod_##type##__##name##_device_table Remove the const attribute from the alias to avoid the duplicate specifier. After all it is only an alias and the attribute shouldn't have any effect. Signed-off-by: NMatthias Kaehlcke <mka@chromium.org> Signed-off-by: NJessica Yu <jeyu@kernel.org>
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- 01 7月, 2017 1 次提交
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由 Kees Cook 提交于
This marks many critical kernel structures for randomization. These are structures that have been targeted in the past in security exploits, or contain functions pointers, pointers to function pointer tables, lists, workqueues, ref-counters, credentials, permissions, or are otherwise sensitive. This initial list was extracted from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Left out of this list is task_struct, which requires special handling and will be covered in a subsequent patch. Signed-off-by: NKees Cook <keescook@chromium.org>
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- 14 6月, 2017 2 次提交
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由 Jeremy Linton 提交于
Each module has a list of enum's its contributing to the enum map, rename that entry to reflect its use by more than enums. Link: http://lkml.kernel.org/r/20170531215653.3240-4-jeremy.linton@arm.comSigned-off-by: NJeremy Linton <jeremy.linton@arm.com> Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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由 Jeremy Linton 提交于
Each enum is loaded into the trace_enum_map, as we are now using this for more than enums rename it. Link: http://lkml.kernel.org/r/20170531215653.3240-3-jeremy.linton@arm.comSigned-off-by: NJeremy Linton <jeremy.linton@arm.com> Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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- 24 4月, 2017 1 次提交
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由 Gao Feng 提交于
The prototypes of try_module_get are different with different macro. When enable module and module unload, it returns bool, but others not. Make the return type for try_module_get consistent across all module config options. Signed-off-by: NGao Feng <fgao@ikuai8.com> [jeyu: slightly amended changelog to make it clearer] Signed-off-by: NJessica Yu <jeyu@redhat.com>
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- 16 3月, 2017 1 次提交
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由 Thomas Gleixner 提交于
If a PER_CPU struct which contains a spin_lock is statically initialized via: DEFINE_PER_CPU(struct foo, bla) = { .lock = __SPIN_LOCK_UNLOCKED(bla.lock) }; then lockdep assigns a seperate key to each lock because the logic for assigning a key to statically initialized locks is to use the address as the key. With per CPU locks the address is obvioulsy different on each CPU. That's wrong, because all locks should have the same key. To solve this the following modifications are required: 1) Extend the is_kernel/module_percpu_addr() functions to hand back the canonical address of the per CPU address, i.e. the per CPU address minus the per CPU offset. 2) Check the lock address with these functions and if the per CPU check matches use the returned canonical address as the lock key, so all per CPU locks have the same key. 3) Move the static_obj(key) check into look_up_lock_class() so this check can be avoided for statically initialized per CPU locks. That's required because the canonical address fails the static_obj(key) check for obvious reasons. Reported-by: NMike Galbraith <efault@gmx.de> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> [ Merged Dan's fixups for !MODULES and !SMP into this patch. ] Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Murphy <dmurphy@ti.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20170227143736.pectaimkjkan5kow@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 10 2月, 2017 1 次提交
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由 Paul Gortmaker 提交于
With hopefully most/all users of module.h that were looking for exception table functions moved over to the new extable.h header, we can remove the back-compat include that let us transition without introducing build regressions. Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: NRusty Russell <rusty@rustcorp.com.au> Acked-by: NJessica Yu <jeyu@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
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- 08 2月, 2017 1 次提交
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由 Laura Abbott 提交于
Both of these options are poorly named. The features they provide are necessary for system security and should not be considered debug only. Change the names to CONFIG_STRICT_KERNEL_RWX and CONFIG_STRICT_MODULE_RWX to better describe what these options do. Signed-off-by: NLaura Abbott <labbott@redhat.com> Acked-by: NJessica Yu <jeyu@redhat.com> Signed-off-by: NKees Cook <keescook@chromium.org>
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- 07 2月, 2017 1 次提交
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由 Arnd Bergmann 提交于
clang warns about unused inline functions by default: arch/arm/crypto/aes-cipher-glue.c:68:1: warning: unused function '__inittest' [-Wunused-function] arch/arm/crypto/aes-cipher-glue.c:69:1: warning: unused function '__exittest' [-Wunused-function] As these appear in every single module, let's just disable the warnings by marking the two functions as __maybe_unused. Signed-off-by: NArnd Bergmann <arnd@arndb.de> Reviewed-by: NMiroslav Benes <mbenes@suse.cz> Acked-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NJessica Yu <jeyu@redhat.com>
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- 04 2月, 2017 1 次提交
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由 Ard Biesheuvel 提交于
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 d4703aef ("module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y") Acked-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 04 1月, 2017 1 次提交
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由 Jean Delvare 提交于
Struct module is already declared at the beginning of the file, no need to declare it again. Signed-off-by: NJean Delvare <jdelvare@suse.de> Fixes: 93c2e105 ("module: Optimize __module_address() using a latched RB-tree") Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Jessica Yu <jeyu@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: NJessica Yu <jeyu@redhat.com>
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- 27 11月, 2016 2 次提交
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由 Anson Jacob 提交于
Fix checkpatch.pl warning: ERROR: trailing whitespace Signed-off-by: NAnson Jacob <ansonjacob.aj@gmail.com> Signed-off-by: NJessica Yu <jeyu@redhat.com>
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由 Petr Mladek 提交于
The commit 66cc69e3 ("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 2bc2d61a ("[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 25ddbb18 ("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: NPetr 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: NJessica Yu <jeyu@redhat.com>
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- 04 8月, 2016 2 次提交
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由 Jessica Yu 提交于
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: NJessica Yu <jeyu@redhat.com> Acked-by: NKees Cook <keescook@chromium.org> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Paul Gortmaker 提交于
For historical reasons (i.e. pre-git) the exception table stuff was buried in the middle of the module.h file. I noticed this while doing an audit for needless includes of module.h and found core kernel files (both arch specific and arch independent) were just including module.h for this. The converse is also true, in that conventional drivers, be they for filesystems or actual hardware peripherals or similar, do not normally care about the exception tables. Here we fork the exception table content out of module.h into a new file called extable.h -- and temporarily include it into the module.h itself. Then we will work our way across the arch independent and arch specific files needing just exception table content, and move them off module.h and onto extable.h Once that is done, we can remove the extable.h from module.h and in doing it like this, we avoid introducing build failures into the git history. The gain here is that module.h gets a bit smaller, across all modular drivers that we build for allmodconfig. Also the core files that only need exception table stuff don't have an include of module.h that brings in lots of extra stuff and just looks generally out of place. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 27 7月, 2016 1 次提交
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由 Jiri Kosina 提交于
__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: NJiri Kosina <jkosina@suse.cz> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 01 4月, 2016 1 次提交
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由 Jessica Yu 提交于
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: NJessica Yu <jeyu@redhat.com> Reviewed-by: NMiroslav Benes <mbenes@suse.cz> Acked-by: NJosh Poimboeuf <jpoimboe@redhat.com> Acked-by: NRusty Russell <rusty@rustcorp.com.au> Reviewed-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NJiri Kosina <jkosina@suse.cz>
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- 03 2月, 2016 1 次提交
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由 Rusty Russell 提交于
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: NWeilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 05 12月, 2015 2 次提交
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由 Rusty Russell 提交于
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: NJosh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NJiri Kosina <jkosina@suse.cz>
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由 Rusty Russell 提交于
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: NPeter Zijlstra <peterz@infradead.org> Reviewed-by: NJosh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NJiri Kosina <jkosina@suse.cz>
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- 06 7月, 2015 1 次提交
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由 Paul Gortmaker 提交于
Modular users will always be users of init functionality, but users of init functionality are not necessarily always modules. Hence any functionality like module_init and module_exit would be more at home in the module.h file. And module.h should explicitly include init.h to make the dependency clear. We've already done all the legwork needed to ensure that this move does not cause any build regressions due to implicit header file include assumptions about where module_init lives. Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
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- 28 6月, 2015 1 次提交
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由 Rusty Russell 提交于
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: NStephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 23 6月, 2015 1 次提交
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由 Dan Streetman 提交于
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: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NDan Streetman <ddstreet@ieee.org> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 28 5月, 2015 3 次提交
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由 Peter Zijlstra 提交于
Andrew worried about the overhead on small systems; only use the fancy code when either perf or tracing is enabled. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Requested-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Peter Zijlstra 提交于
Currently __module_address() is using a linear search through all modules in order to find the module corresponding to the provided address. With a lot of modules this can take a lot of time. One of the users of this is kernel_text_address() which is employed in many stack unwinders; which in turn are used by perf-callchain and ftrace (possibly from NMI context). So by optimizing __module_address() we optimize many stack unwinders which are used by both perf and tracing in performance sensitive code. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Peter Zijlstra 提交于
Currently the RCU usage in module is an inconsistent mess of RCU and RCU-sched, this is broken for CONFIG_PREEMPT where synchronize_rcu() does not imply synchronize_sched(). Most usage sites use preempt_{dis,en}able() which is RCU-sched, but (most of) the modification sites use synchronize_rcu(). With the exception of the module bug list, which actually uses RCU. Convert everything over to RCU-sched. Furthermore add lockdep asserts to all sites, because it's not at all clear to me the required locking is observed, esp. on exported functions. Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: N"Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 25 5月, 2015 1 次提交
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由 Dmitry Torokhov 提交于
Commit f2411da7 ("driver-core: add driver module asynchronous probe support") broke build in case modules are disabled, because in this case "struct module" is not defined and we can't dereference it. Let's define module_requested_async_probing() helper and stub it out if modules are disabled. Reported-by: Nkbuild test robot <fengguang.wu@intel.com> Reported-by: NStephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 20 5月, 2015 1 次提交
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由 Luis R. Rodriguez 提交于
Some init systems may wish to express the desire to have device drivers run their probe() code asynchronously. This implements support for this and allows userspace to request async probe as a preference through a generic shared device driver module parameter, async_probe. Implementation for async probe is supported through a module parameter given that since synchronous probe has been prevalent for years some userspace might exist which relies on the fact that the device driver will probe synchronously and the assumption that devices it provides will be immediately available after this. Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com> Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 14 5月, 2015 1 次提交
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由 Steven Rostedt (Red Hat) 提交于
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structures ftrace_event_call and ftrace_event_class have nothing to do with the function hooks, and are really trace_event structures. Rename ftrace_event_* to trace_event_*. Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 23 4月, 2015 1 次提交
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由 Herbert Xu 提交于
Currently we're hiding mod->sig_ok under an ifdef in open code. This patch adds a module_sig_ok accessor function and removes that ifdef. Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au> Acked-by: NRusty Russell <rusty@rustcorp.com.au>
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- 08 4月, 2015 1 次提交
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由 Steven Rostedt (Red Hat) 提交于
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.auAcked-by: NRusty Russell <rusty@rustcorp.com.au> Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 17 3月, 2015 1 次提交
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由 Petr Mladek 提交于
There is a notifier that handles live patches for coming and going modules. It takes klp_mutex lock to avoid races with coming and going patches but it does not keep the lock all the time. Therefore the following races are possible: 1. The notifier is called sometime in STATE_MODULE_COMING. The module is visible by find_module() in this state all the time. It means that new patch can be registered and enabled even before the notifier is called. It might create wrong order of stacked patches, see below for an example. 2. New patch could still see the module in the GOING state even after the notifier has been called. It will try to initialize the related object structures but the module could disappear at any time. There will stay mess in the structures. It might even cause an invalid memory access. This patch solves the problem by adding a boolean variable into struct module. The value is true after the coming and before the going handler is called. New patches need to be applied when the value is true and they need to ignore the module when the value is false. Note that we need to know state of all modules on the system. The races are related to new patches. Therefore we do not know what modules will get patched. Also note that we could not simply ignore going modules. The code from the module could be called even in the GOING state until mod->exit() finishes. If we start supporting patches with semantic changes between function calls, we need to apply new patches to any still usable code. See below for an example. Finally note that the patch solves only the situation when a new patch is registered. There are no such problems when the patch is being removed. It does not matter who disable the patch first, whether the normal disable_patch() or the module notifier. There is nothing to do once the patch is disabled. Alternative solutions: ====================== + reject new patches when a patched module is coming or going; this is ugly + wait with adding new patch until the module leaves the COMING and GOING states; this might be dangerous and complicated; we would need to release kgr_lock in the middle of the patch registration to avoid a deadlock with the coming and going handlers; also we might need a waitqueue for each module which seems to be even bigger overhead than the boolean + stop modules from entering COMING and GOING states; wait until modules leave these states when they are already there; looks complicated; we would need to ignore the module that asked to stop the others to avoid a deadlock; also it is unclear what to do when two modules asked to stop others and both are in COMING state (situation when two new patches are applied) + always register/enable new patches and fix up the potential mess (registered patches order) in klp_module_init(); this is nasty and prone to regressions in the future development + add another MODULE_STATE where the kallsyms are visible but the module is not used yet; this looks too complex; the module states are checked on "many" locations Example of patch stacking breakage: =================================== The notifier could _not_ _simply_ ignore already initialized module objects. For example, let's have three patches (P1, P2, P3) for functions a() and b() where a() is from vmcore and b() is from a module M. Something like: a() b() P1 a1() b1() P2 a2() b2() P3 a3() b3(3) If you load the module M after all patches are registered and enabled. The ftrace ops for function a() and b() has listed the functions in this order: ops_a->func_stack -> list(a3,a2,a1) ops_b->func_stack -> list(b3,b2,b1) , so the pointer to b3() is the first and will be used. Then you might have the following scenario. Let's start with state when patches P1 and P2 are registered and enabled but the module M is not loaded. Then ftrace ops for b() does not exist. Then we get into the following race: CPU0 CPU1 load_module(M) complete_formation() mod->state = MODULE_STATE_COMING; mutex_unlock(&module_mutex); klp_register_patch(P3); klp_enable_patch(P3); # STATE 1 klp_module_notify(M) klp_module_notify_coming(P1); klp_module_notify_coming(P2); klp_module_notify_coming(P3); # STATE 2 The ftrace ops for a() and b() then looks: STATE1: ops_a->func_stack -> list(a3,a2,a1); ops_b->func_stack -> list(b3); STATE2: ops_a->func_stack -> list(a3,a2,a1); ops_b->func_stack -> list(b2,b1,b3); therefore, b2() is used for the module but a3() is used for vmcore because they were the last added. Example of the race with going modules: ======================================= CPU0 CPU1 delete_module() #SYSCALL try_stop_module() mod->state = MODULE_STATE_GOING; mutex_unlock(&module_mutex); klp_register_patch() klp_enable_patch() #save place to switch universe b() # from module that is going a() # from core (patched) mod->exit(); Note that the function b() can be called until we call mod->exit(). If we do not apply patch against b() because it is in MODULE_STATE_GOING, it will call patched a() with modified semantic and things might get wrong. [jpoimboe@redhat.com: use one boolean instead of two] Signed-off-by: NPetr Mladek <pmladek@suse.cz> Acked-by: NJosh Poimboeuf <jpoimboe@redhat.com> Acked-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NJiri Kosina <jkosina@suse.cz>
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- 14 2月, 2015 1 次提交
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由 Andrey Ryabinin 提交于
MODULE_DEVICE_TABLE() macro used to create aliases to device tables. Normally alias should have the same type as aliased symbol. Device tables are arrays, so they have 'struct type##_device_id[x]' types. Alias created by MODULE_DEVICE_TABLE() will have non-array type - 'struct type##_device_id'. This inconsistency confuses compiler, it could make a wrong assumption about variable's size which leads KASan to produce a false positive report about out of bounds access. For every global variable compiler calls __asan_register_globals() passing information about global variable (address, size, size with redzone, name ...) __asan_register_globals() poison symbols redzone to detect possible out of bounds accesses. When symbol has an alias __asan_register_globals() will be called as for symbol so for alias. Compiler determines size of variable by size of variable's type. Alias and symbol have the same address, so if alias have the wrong size part of memory that actually belongs to the symbol could be poisoned as redzone of alias symbol. By fixing type of alias symbol we will fix size of it, so __asan_register_globals() will not poison valid memory. Signed-off-by: NAndrey 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: NAndrey 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: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 22 1月, 2015 1 次提交
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由 Rusty Russell 提交于
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: NJames Bottomley <James.Bottomley@HansenPartnership.com> Reviewed-by: NMasami Hiramatsu <maasami.hiramatsu.pt@hitachi.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 11 11月, 2014 1 次提交
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由 Masami Hiramatsu 提交于
Replace module_ref per-cpu complex reference counter with an atomic_t simple refcnt. This is for code simplification. Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 27 7月, 2014 1 次提交
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由 Petr Mladek 提交于
The within_module*() functions return only true or false. Let's use bool as the return type. Note that it should not change kABI because these are inline functions. Signed-off-by: NPetr Mladek <pmladek@suse.cz> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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