user/sven/linux.git/include/linux/module.h, branch v4.9.69

modules: add ro_after_init support

2016-08-04T00:46:55Z

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 Acked-by: Kees Cook Signed-off-by: Rusty Russell

exceptions: fork exception table content from module.h into extable.h

2016-08-04T00:46:54Z

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 Cc: Linus Torvalds Signed-off-by: Paul Gortmaker Signed-off-by: Rusty Russell

module: fix noreturn attribute for __module_put_and_exit()

2016-07-27T03:08:00Z

__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 Signed-off-by: Rusty Russell

module: preserve Elf information for livepatch modules

2016-04-01T13:00:10Z

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 Reviewed-by: Miroslav Benes Acked-by: Josh Poimboeuf Acked-by: Rusty Russell Reviewed-by: Rusty Russell Signed-off-by: Jiri Kosina

modules: fix longstanding /proc/kallsyms vs module insertion race.

2016-02-03T06:28:15Z

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 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell

module: clean up RO/NX handling.

2015-12-04T21:46:26Z

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 Signed-off-by: Rusty Russell Signed-off-by: Jiri Kosina

module: use a structure to encapsulate layout.

2015-12-04T21:46:25Z

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 Reviewed-by: Josh Poimboeuf Signed-off-by: Rusty Russell Signed-off-by: Jiri Kosina

module: relocate module_init from init.h to module.h

2015-07-06T03:59:14Z

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 Acked-by: Rusty Russell Signed-off-by: Paul Gortmaker

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

2015-07-01T17:49:25Z

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() ...

param: fix module param locks when !CONFIG_SYSFS.

2015-06-28T05:16:14Z

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 Signed-off-by: Rusty Russell