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* CONFIG_SYMBOL_PREFIX: cleanup.Rusty Russell2013-03-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have CONFIG_SYMBOL_PREFIX, which three archs define to the string "_". But Al Viro broke this in "consolidate cond_syscall and SYSCALL_ALIAS declarations" (in linux-next), and he's not the first to do so. Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to prefix it so something. So various places define helpers which are defined to nothing if CONFIG_SYMBOL_PREFIX isn't set: 1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX. 2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym) 3) include/linux/export.h defines MODULE_SYMBOL_PREFIX. 4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7) 5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym) 6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX 7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version for pasting. (arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too). Let's solve this properly: 1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX. 2) Make linux/export.h usable from asm. 3) Define VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR(). 4) Make everyone use them. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: James Hogan <james.hogan@imgtec.com> Tested-by: James Hogan <james.hogan@imgtec.com> (metag)
* module: constify within_module_*Sasha Levin2013-01-211-2/+2
| | | | | | | | These helper functions just check a set intersection with a range, and don't actually modify struct module. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* module: add new state MODULE_STATE_UNFORMED.Rusty Russell2013-01-121-5/+5
| | | | | | | | | You should never look at such a module, so it's excised from all paths which traverse the modules list. We add the state at the end, to avoid gratuitous ABI break (ksplice). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* module: signature checking hookRusty Russell2012-10-101-0/+8
| | | | | | | | | | | | | | | | | We do a very simple search for a particular string appended to the module (which is cache-hot and about to be SHA'd anyway). There's both a config option and a boot parameter which control whether we accept or fail with unsigned modules and modules that are signed with an unknown key. If module signing is enabled, the kernel will be tainted if a module is loaded that is unsigned or has a signature for which we don't have the key. (Useful feedback and tweaks by David Howells <dhowells@redhat.com>) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* module: move __module_get and try_module_get() out of line.Steven Rostedt2012-03-261-28/+4
| | | | | | | | | | | | | | | | | | | | | | | With the preempt, tracepoint and everything, it's getting a bit chubby. For an Ubuntu-based config: Before: $ size -t `find * -name '*.ko'` | grep TOTAL 56199906 3870760 1606616 61677282 3ad1ee2 (TOTALS) $ size vmlinux text data bss dec hex filename 8509342 850368 3358720 12718430 c2115e vmlinux After: $ size -t `find * -name '*.ko'` | grep TOTAL 56183760 3867892 1606616 61658268 3acd49c (TOTALS) $ size vmlinux text data bss dec hex filename 8501842 849088 3358720 12709650 c1ef12 vmlinux Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (made all out-of-line)
* module: struct module_ref should contains long fieldsEric Dumazet2012-01-131-5/+16
| | | | | | | | | | | | | | | | | | | module_ref contains two "unsigned int" fields. Thats now too small, since some machines can open more than 2^32 files. Check commit 518de9b39e8 (fs: allow for more than 2^31 files) for reference. We can add an aligned(2 * sizeof(unsigned long)) attribute to force alloc_percpu() allocating module_ref areas in single cache lines. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Rusty Russell <rusty@rustcorp.com.au> CC: Tejun Heo <tj@kernel.org> CC: Robin Holt <holt@sgi.com> CC: David Miller <davem@davemloft.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* module.h: relocate MODULE_PARM_DESC into moduleparam.hPaul Gortmaker2011-10-311-5/+0
| | | | | | | | | | | There are files which use module_param and MODULE_PARM_DESC back to back. They only include moduleparam.h which makes sense, but the implicit presence of module.h everywhere hid the fact that MODULE_PARM_DESC wasn't in moduleparam.h at all. Relocate the macro to moduleparam.h so that the moduleparam infrastructure can be used independently of module.h Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* module.h: split out the EXPORT_SYMBOL into export.hPaul Gortmaker2011-10-311-67/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | A lot of files pull in module.h when all they are really looking for is the basic EXPORT_SYMBOL functionality. The recent data from Ingo[1] shows that this is one of several instances that has a significant impact on compile times, and it should be targeted for factoring out (as done here). Note that several commonly used header files in include/* directly include <linux/module.h> themselves (some 34 of them!) The most commonly used ones of these will have to be made independent of module.h before the full benefit of this change can be realized. We also transition THIS_MODULE from module.h to export.h, since there are lots of files with subsystem structs that in turn will have a struct module *owner and only be doing: .owner = THIS_MODULE; and absolutely nothing else modular. So, we also want to have the THIS_MODULE definition present in the lightweight header. [1] https://lkml.org/lkml/2011/5/23/76 Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* Tracepoint: Dissociate from module mutexMathieu Desnoyers2011-08-101-12/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Copy the information needed from struct module into a local module list held within tracepoint.c from within the module coming/going notifier. This vastly simplifies locking of tracepoint registration / unregistration, because we don't have to take the module mutex to register and unregister tracepoints anymore. Steven Rostedt ran into dependency problems related to modules mutex vs kprobes mutex vs ftrace mutex vs tracepoint mutex that seems to be hard to fix without removing this dependency between tracepoint and module mutex. (note: it should be investigated whether kprobes could benefit of being dissociated from the modules mutex too.) This also fixes module handling of tracepoint list iterators, because it was expecting the list to be sorted by pointer address. Given we have control on our own list now, it's OK to sort this list which has tracepoints as its only purpose. The reason why this sorting is required is to handle the fact that seq files (and any read() operation from user-space) cannot hold the tracepoint mutex across multiple calls, so list entries may vanish between calls. With sorting, the tracepoint iterator becomes usable even if the list don't contain the exact item pointed to by the iterator anymore. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Jason Baron <jbaron@redhat.com> CC: Ingo Molnar <mingo@elte.hu> CC: Lai Jiangshan <laijs@cn.fujitsu.com> CC: Peter Zijlstra <a.p.zijlstra@chello.nl> CC: Thomas Gleixner <tglx@linutronix.de> CC: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Link: http://lkml.kernel.org/r/20110810191839.GC8525@Krystal Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* module: add /sys/module/<name>/uevent filesKay Sievers2011-07-241-0/+1
| | | | | | | | | | | | | | | | | Userspace wants to manage module parameters with udev rules. This currently only works for loaded modules, but not for built-in ones. To allow access to the built-in modules we need to re-trigger all module load events that happened before any userspace was running. We already do the same thing for all devices, subsystems(buses) and drivers. This adds the currently missing /sys/module/<name>/uevent files to all module entries. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (split & trivial fix)
* module: change attr callbacks to take struct module_kobjectKay Sievers2011-07-241-11/+12
| | | | | | | | This simplifies the next patch, where we have an attribute on a builtin module (ie. module == NULL). Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (split into 2)
* module: Sort exported symbolsAlessio Igor Bogani2011-05-191-2/+2
| | | | | | | | | | | | | | | | | This patch places every exported symbol in its own section (i.e. "___ksymtab+printk"). Thus the linker will use its SORT() directive to sort and finally merge all symbol in the right and final section (i.e. "__ksymtab"). The symbol prefixed archs use an underscore as prefix for symbols. To avoid collision we use a different character to create the temporary section names. This work was supported by a hardware donation from the CE Linux Forum. Signed-off-by: Alessio Igor Bogani <abogani@kernel.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (folded in '+' fixup) Tested-by: Dirk Behme <dirk.behme@googlemail.com>
* module: each_symbol_section instead of each_symbolRusty Russell2011-05-191-2/+3
| | | | | | | | | | Instead of having a callback function for each symbol in the kernel, have a callback for each array of symbols. This eases the logic when we move to sorted symbols and binary search. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Alessio Igor Bogani <abogani@kernel.org>
* module: remove 64 bit alignment padding from struct module with CONFIG_TRACE*Richard Kennedy2011-05-191-6/+7
| | | | | | | | | | Reorder struct module to remove 24 bytes of alignment padding on 64 bit builds when the CONFIG_TRACE options are selected. This allows the structure to fit into one fewer cache lines, and its size drops from 592 to 568 on x86_64. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* module: do not hide __modver_version_show declaration behind ifdefDmitry Torokhov2011-05-191-2/+3
| | | | | | | | | | | | | Doing so prevents the following warning from sparse: CHECK kernel/params.c kernel/params.c:817:9: warning: symbol '__modver_version_show' was not declared. Should it be static? since kernel/params.c is never compiled with MODULE being set. Signed-off-by: Dmitry Torokhov <dtor@vmware.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* module: deal with alignment issues in built-in module versionsDmitry Torokhov2011-05-191-5/+5
| | | | | | | | | | | | | | | | | | | | On m68k natural alignment is 2-byte boundary but we are trying to align structures in __modver section on sizeof(void *) boundary. This causes trouble when we try to access elements in this section in array-like fashion when create "version" attributes for built-in modules. Moreover, as DaveM said, we can't reliably put structures into independent objects, put them into a special section, and then expect array access over them (via the section boundaries) after linking the objects together to just "work" due to variable alignment choices in different situations. The only solution that seems to work reliably is to make an array of plain pointers to the objects in question and put those pointers in the special section. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Dmitry Torokhov <dtor@vmware.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* module: explicitly align module_version_attribute structureDmitry Torokhov2011-02-211-1/+1
| | | | | | | | | | | | | We force particular alignment when we generate attribute structures when generation MODULE_VERSION() data and we need to make sure that this alignment is followed when we iterate over these structures, otherwise we may crash on platforms whose natural alignment is not sizeof(void *), such as m68k. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Dmitry Torokhov <dtor@vmware.com> [ There are more issues here, but the fixes are incredibly ugly - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tracepoints: Fix section alignment using pointer arrayMathieu Desnoyers2011-02-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the tracepoints more robust, making them solid enough to handle compiler changes by not relying on anything based on compiler-specific behavior with respect to structure alignment. Implement an approach proposed by David Miller: use an array of const pointers to refer to the individual structures, and export this pointer array through the linker script rather than the structures per se. It will consume 32 extra bytes per tracepoint (24 for structure padding and 8 for the pointers), but are less likely to break due to compiler changes. History: commit 7e066fb8 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE() added the aligned(32) type and variable attribute to the tracepoint structures to deal with gcc happily aligning statically defined structures on 32-byte multiples. One attempt was to use a 8-byte alignment for tracepoint structures by applying both the variable and type attribute to tracepoint structures definitions and declarations. It worked fine with gcc 4.5.1, but broke with gcc 4.4.4 and 4.4.5. The reason is that the "aligned" attribute only specify the _minimum_ alignment for a structure, leaving both the compiler and the linker free to align on larger multiples. Because tracepoint.c expects the structures to be placed as an array within each section, up-alignment cause NULL-pointer exceptions due to the extra unexpected padding. (this patch applies on top of -tip) Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: David S. Miller <davem@davemloft.net> LKML-Reference: <20110126222622.GA10794@Krystal> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Ingo Molnar <mingo@elte.hu> CC: Thomas Gleixner <tglx@linutronix.de> CC: Andrew Morton <akpm@linux-foundation.org> CC: Peter Zijlstra <peterz@infradead.org> CC: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Replace trace_event struct array with pointer arraySteven Rostedt2011-02-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the trace_event structures are placed in the _ftrace_events section, and at link time, the linker makes one large array of all the trace_event structures. On boot up, this array is read (much like the initcall sections) and the events are processed. The problem is that there is no guarantee that gcc will place complex structures nicely together in an array format. Two structures in the same file may be placed awkwardly, because gcc has no clue that they are suppose to be in an array. A hack was used previous to force the alignment to 4, to pack the structures together. But this caused alignment issues with other architectures (sparc). Instead of packing the structures into an array, the structures' addresses are now put into the _ftrace_event section. As pointers are always the natural alignment, gcc should always pack them tightly together (otherwise initcall, extable, etc would also fail). By having the pointers to the structures in the section, we can still iterate the trace_events without causing unnecessary alignment problems with other architectures, or depending on the current behaviour of gcc that will likely change in the future just to tick us kernel developers off a little more. The _ftrace_event section is also moved into the .init.data section as it is now only needed at boot up. Suggested-by: David Miller <davem@davemloft.net> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* module: fix linker error for MODULE_VERSION when !MODULE and CONFIG_SYSFS=nRusty Russell2011-01-241-1/+1
| | | | | | | | | | | lib/built-in.o:(__modver+0x8): undefined reference to `__modver_version_show' lib/built-in.o:(__modver+0x2c): undefined reference to `__modver_version_show' Simplest to just not emit anything: if they've disabled SYSFS they probably want the smallest kernel possible. Reported-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* module: show version information for built-in modules in sysfsDmitry Torokhov2011-01-241-0/+27
| | | | | | | | | | | | | | | | Currently only drivers that are built as modules have their versions shown in /sys/module/<module_name>/version, but this information might also be useful for built-in drivers as well. This especially important for drivers that do not define any parameters - such drivers, if built-in, are completely invisible from userspace. This patch changes MODULE_VERSION() macro so that in case when we are compiling built-in module, version information is stored in a separate section. Kernel then uses this data to create 'version' sysfs attribute in the same fashion it creates attributes for module parameters. Signed-off-by: Dmitry Torokhov <dtor@vmware.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* Merge commit 'v2.6.37-rc7' into x86/securityIngo Molnar2010-12-231-1/+1
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| * module: Update prototype for ref_module (formerly use_module)Anders Kaseorg2010-11-241-1/+1
| | | | | | | | | | | | | | | | | | | | Commit 9bea7f23952d5948f8e5dfdff4de09bb9981fb5f renamed use_module to ref_module (and changed its return value), but forgot to update this prototype in module.h. Signed-off-by: Anders Kaseorg <andersk@ksplice.com> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | x86: Add RO/NX protection for loadable kernel modulesmatthieu castet2010-11-181-1/+10
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge commit 'v2.6.36-rc7' into perf/coreIngo Molnar2010-10-081-3/+2
|\ | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/module.c Merge reason: Resolve the conflict, pick up fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * modules: Fix module_bug_list list corruption raceLinus Torvalds2010-10-051-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With all the recent module loading cleanups, we've minimized the code that sits under module_mutex, fixing various deadlocks and making it possible to do most of the module loading in parallel. However, that whole conversion totally missed the rather obscure code that adds a new module to the list for BUG() handling. That code was doubly obscure because (a) the code itself lives in lib/bugs.c (for dubious reasons) and (b) it gets called from the architecture-specific "module_finalize()" rather than from generic code. Calling it from arch-specific code makes no sense what-so-ever to begin with, and is now actively wrong since that code isn't protected by the module loading lock any more. So this commit moves the "module_bug_{finalize,cleanup}()" calls away from the arch-specific code, and into the generic code - and in the process protects it with the module_mutex so that the list operations are now safe. Future fixups: - move the module list handling code into kernel/module.c where it belongs. - get rid of 'module_bug_list' and just use the regular list of modules (called 'modules' - imagine that) that we already create and maintain for other reasons. Reported-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Adrian Bunk <bunk@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | jump label: Base patch for jump labelJason Baron2010-09-221-1/+4
|/ | | | | | | | | | | | | | | | | base patch to implement 'jump labeling'. Based on a new 'asm goto' inline assembly gcc mechanism, we can now branch to labels from an 'asm goto' statment. This allows us to create a 'no-op' fastpath, which can subsequently be patched with a jump to the slowpath code. This is useful for code which might be rarely used, but which we'd like to be able to call, if needed. Tracepoints are the current usecase that these are being implemented for. Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jason Baron <jbaron@redhat.com> LKML-Reference: <ee8b3595967989fdaf84e698dc7447d315ce972a.1284733808.git.jbaron@redhat.com> [ cleaned up some formating ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* module: Make module sysfs functions private.Rusty Russell2010-06-051-33/+0
| | | | | | | | | | | These were placed in the header in ef665c1a06 to get the various SYSFS/MODULE config combintations to compile. That may have been necessary then, but it's not now. These functions are all local to module.c. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Randy Dunlap <randy.dunlap@oracle.com>
* module: fix kdb's illicit use of struct module_use.Rusty Russell2010-06-051-0/+7
| | | | | | | | | Linus changed the structure, and luckily this didn't compile any more. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Martin Hicks <mort@sgi.com>
* module: Make the 'usage' lists be two-wayLinus Torvalds2010-06-051-1/+3
| | | | | | | | | | | | | | | | | | | | | | When adding a module that depends on another one, we used to create a one-way list of "modules_which_use_me", so that module unloading could see who needs a module. It's actually quite simple to make that list go both ways: so that we not only can see "who uses me", but also see a list of modules that are "used by me". In fact, we always wanted that list in "module_unload_free()": when we unload a module, we want to also release all the other modules that are used by that module. But because we didn't have that list, we used to first iterate over all modules, and then iterate over each "used by me" list of that module. By making the list two-way, we simplify module_unload_free(), and it allows for some trivial fixes later too. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cleaned & rebased)
* Merge branch 'linus' into tracing/coreIngo Molnar2010-04-081-6/+15
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: include/linux/module.h kernel/module.c Semantic conflict: include/trace/events/module.h Merge reason: Resolve the conflict with upstream commit 5fbfb18 ("Fix up possibly racy module refcounting") Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * Fix up possibly racy module refcountingNick Piggin2010-04-051-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Module refcounting is implemented with a per-cpu counter for speed. However there is a race when tallying the counter where a reference may be taken by one CPU and released by another. Reference count summation may then see the decrement without having seen the previous increment, leading to lower than expected count. A module which never has its actual reference drop below 1 may return a reference count of 0 due to this race. Module removal generally runs under stop_machine, which prevents this race causing bugs due to removal of in-use modules. However there are other real bugs in module.c code and driver code (module_refcount is exported) where the callers do not run under stop_machine. Fix this by maintaining running per-cpu counters for the number of module refcount increments and the number of refcount decrements. The increments are tallied after the decrements, so any decrement seen will always have its corresponding increment counted. The final refcount is the difference of the total increments and decrements, preventing a low-refcount from being returned. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * module: add stub for is_module_percpu_addressRandy Dunlap2010-03-311-0/+5
| | | | | | | | | | | | | | | | | | | | Fix build for CONFIG_MODULES not enabled by providing a stub for is_module_percpu_address(). kernel/lockdep.c:605: error: implicit declaration of function 'is_module_percpu_address' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * percpu, module: implement and use is_kernel/module_percpu_address()Tejun Heo2010-03-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | lockdep has custom code to check whether a pointer belongs to static percpu area which is somewhat broken. Implement proper is_kernel/module_percpu_address() and replace the custom code. On UP, percpu variables are regular static variables and can't be distinguished from them. Always return %false on UP. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@redhat.com>
| * module: encapsulate percpu handling better and record percpu_sizeTejun Heo2010-03-291-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | Better encapsulate module static percpu area handling so that code outsidef of CONFIG_SMP ifdef doesn't deal with mod->percpu directly and add mod->percpu_size and record percpu_size in it. Both percpu fields are compiled out on UP. While at it, mark mod->percpu w/ __percpu. This is to prepare for is_module_percpu_address(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au>
* | tracing: Remove side effect from module tracepoints that caused a GPFLi Zefan2010-03-311-4/+2
|/ | | | | | | | | | | | | | | | | | | | Remove the @refcnt argument, because it has side-effects, and arguments with side-effects are not skipped by the jump over disabled instrumentation and are executed even when the tracepoint is disabled. This was also causing a GPF as found by Randy Dunlap: Subject: 2.6.33 GP fault only when built with tracing LKML-Reference: <4BA2B69D.3000309@oracle.com> Note, the current 2.6.34-rc has a fix for the actual cause of the GPF, but this fixes one of its triggers. Tested-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4BA97FA7.6040406@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* sysctl extern cleanup: moduleDave Young2010-03-121-0/+1
| | | | | | | | | | | | | Extern declarations in sysctl.c should be moved to their own header file, and then include them in relavant .c files. Move modprobe_path extern declaration to linux/kmod.h Move modules_disabled extern declaration to linux/module.h Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* percpu: add __percpu sparse annotations to core kernel subsystemsTejun Heo2010-02-171-1/+1
| | | | | | | | | | | | | | | | | | | Add __percpu sparse annotations to core subsystems. These annotations are to make sparse consider percpu variables to be in a different address space and warn if accessed without going through percpu accessors. This patch doesn't affect normal builds. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-mm@kvack.org Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Eric Biederman <ebiederm@xmission.com>
* local_t: Move local.h include to ringbuffer.c and ring_buffer_benchmark.cChristoph Lameter2010-01-051-1/+0
| | | | | | | | | ringbuffer*.c are the last users of local.h. Remove the include from modules.h and add it to ringbuffer files. Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* module: Use this_cpu_xx to dynamically allocate countersChristoph Lameter2010-01-051-22/+14
| | | | | | | | | | | | | | | | | | Use cpu ops to deal with the per cpu data instead of a local_t. Reduces memory requirements, cache footprint and decreases cycle counts. The this_cpu_xx operations are also used for !SMP mode. Otherwise we could not drop the use of __module_ref_addr() which would make per cpu data handling complicated. this_cpu_xx operations have their own fallback for !SMP. V8-V9: - Leave include asm/module.h since ringbuffer.c depends on it. Nothing else does though. Another patch will deal with that. - Remove spurious free. Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Tejun Heo <tj@kernel.org>
* module: make MODULE_SYMBOL_PREFIX into a CONFIG optionAlan Jenkins2009-12-151-2/+4
| | | | | | | | | | | | | | | | | | | | The next commit will require the use of MODULE_SYMBOL_PREFIX in .tmp_exports-asm.S. Currently it is mixed in with C structure definitions in "asm/module.h". Move the definition of this arch option into Kconfig, so it can be easily accessed by any code. This also lets modpost.c use the same definition. Previously modpost relied on a hardcoded list of architectures in mk_elfconfig.c. A build test for blackfin, one of the two MODULE_SYMBOL_PREFIX archs, showed the generated code was unchanged. vmlinux was identical save for build ids, and an apparently randomized suffix on a single "__key" symbol in the kallsyms data). Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk> Acked-by: Mike Frysinger <vapier@gentoo.org> (blackfin) CC: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* module: preferred way to use MODULE_AUTHORJohannes Berg2009-09-251-1/+4
| | | | | | | | | | | | For the longest time now we've been using multiple MODULE_AUTHOR() statements when a module has more than one author, but the comment here disagrees. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Luciano Coelho <luciano.coelho@nokia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* module: reduce string table for loaded modules (v2)Jan Beulich2009-09-251-1/+1
| | | | | | | | | | Also remove all parts of the string table (referenced by the symbol table) that are not needed for kallsyms use (i.e. which were only referenced by symbols discarded by the previous patch, or not referenced at all for whatever reason). Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* module: reduce symbol table for loaded modules (v2)Jan Beulich2009-09-251-3/+7
| | | | | | | | Discard all symbols not interesting for kallsyms use: absolute, section, and in the common case (!KALLSYMS_ALL) data ones. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* tracing: Remove markersChristoph Hellwig2009-09-181-11/+0
| | | | | | | | | | | | Now that the last users of markers have migrated to the event tracer we can kill off the (now orphan) support code. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20090917173527.GA1699@lst.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* tracing/events: Add module tracepointsLi Zefan2009-08-171-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add trace points to trace module_load, module_free, module_get, module_put and module_request, and use trace_event facility to get the trace output. Here's the sample output: TASK-PID CPU# TIMESTAMP FUNCTION | | | | | <...>-42 [000] 1.758380: module_request: fb0 wait=1 call_site=fb_open ... <...>-60 [000] 3.269403: module_load: scsi_wait_scan <...>-60 [000] 3.269432: module_put: scsi_wait_scan call_site=sys_init_module refcnt=0 <...>-61 [001] 3.273168: module_free: scsi_wait_scan ... <...>-1021 [000] 13.836081: module_load: sunrpc <...>-1021 [000] 13.840589: module_put: sunrpc call_site=sys_init_module refcnt=-1 <...>-1027 [000] 13.848098: module_get: sunrpc call_site=try_module_get refcnt=0 <...>-1027 [000] 13.848308: module_get: sunrpc call_site=get_filesystem refcnt=1 <...>-1027 [000] 13.848692: module_put: sunrpc call_site=put_filesystem refcnt=0 ... modprobe-2587 [001] 1088.437213: module_load: trace_events_sample F modprobe-2587 [001] 1088.437786: module_put: trace_events_sample call_site=sys_init_module refcnt=0 Note: - the taints flag can be 'F', 'C' and/or 'P' if mod->taints != 0 - the module refcnt is percpu, so it can be negative in a specific cpu Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> LKML-Reference: <4A891B3C.5030608@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* kernel: constructor supportPeter Oberparleiter2009-06-181-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | Call constructors (gcc-generated initcall-like functions) during kernel start and module load. Constructors are e.g. used for gcov data initialization. Disable constructor support for usermode Linux to prevent conflicts with host glibc. Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Li Wei <W.Li@Sun.COM> Cc: Michael Ellerman <michaele@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com> Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* headers: move module_bug_finalize()/module_bug_cleanup() definitions into ↵Andrew Morton2009-06-161-0/+17
| | | | | | | | | | | | | | | | | | | module.h They're in linux/bug.h at present, which causes include order tangles. In particular, linux/bug.h cannot be used by linux/atomic.h because, according to Nikanth: linux/bug.h pulls in linux/module.h => linux/spinlock.h => asm/spinlock.h (which uses atomic_inc) => asm/atomic.h. bug.h is a pretty low-level thing and module.h is a higher-level thing, IMO. Cc: Nikanth Karthikesan <knikanth@novell.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* module: trim exception table on init free.Rusty Russell2009-06-121-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | It's theoretically possible that there are exception table entries which point into the (freed) init text of modules. These could cause future problems if other modules get loaded into that memory and cause an exception as we'd see the wrong fixup. The only case I know of is kvm-intel.ko (when CONFIG_CC_OPTIMIZE_FOR_SIZE=n). Amerigo fixed this long-standing FIXME in the x86 version, but this patch is more general. This implements trim_init_extable(); most archs are simple since they use the standard lib/extable.c sort code. Alpha and IA64 use relative addresses in their fixups, so thier trimming is a slight variation. Sparc32 is unique; it doesn't seem to define ARCH_HAS_SORT_EXTABLE, yet it defines its own sort_extable() which overrides the one in lib. It doesn't sort, so we have to mark deleted entries instead of actually trimming them. Inspired-by: Amerigo Wang <amwang@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: linux-alpha@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-ia64@vger.kernel.org
* ftrace: use module notifier for function tracerSteven Rostedt2009-04-171-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | The hooks in the module code for the function tracer must be called before any of that module code runs. The function tracer hooks modify the module (replacing calls to mcount to nops). If the code is executed while the change occurs, then the CPU can take a GPF. To handle the above with a bit of paranoia, I originally implemented the hooks as calls directly from the module code. After examining the notifier calls, it looks as though the start up notify is called before any of the module's code is executed. This makes the use of the notify safe with ftrace. Only the startup notify is required to be "safe". The shutdown simply removes the entries from the ftrace function list, and does not modify any code. This change has another benefit. It removes a issue with a reverse dependency in the mutexes of ftrace_lock and module_mutex. [ Impact: fix lock dependency bug, cleanup ] Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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