kernel/linux.git/include/linux/kmod.h, branch v6.6.132

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61

2019-05-24T15:36:45+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 675 mass ave cambridge ma 02139 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 441 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Michael Ellerman (powerpc) Reviewed-by: Richard Fontana Reviewed-by: Allison Randal Reviewed-by: Kate Stewart Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520071858.739733335@linutronix.de Signed-off-by: Greg Kroah-Hartman

kmod: split off umh headers into its own file

2017-09-09T01:26:51+00:00

In the future usermode helper users do not need to carry in all the of kmod headers declarations. Since kmod.h still includes umh.h this change has no functional changes, each umh user can be cleaned up separately later and with time. Link: http://lkml.kernel.org/r/20170810180618.22457-4-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez Cc: Kees Cook Cc: Dmitry Torokhov Cc: Jessica Yu Cc: Rusty Russell Cc: Michal Marek Cc: Petr Mladek Cc: Miroslav Benes Cc: Josh Poimboeuf Cc: Guenter Roeck Cc: "Eric W. Biederman" Cc: Matt Redfearn Cc: Dan Carpenter Cc: Colin Ian King Cc: Daniel Mentz Cc: David Binderman Cc: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

randstruct: Mark various structs for randomization

2017-06-30T19:00:51+00:00

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: Kees Cook

kmod: make usermodehelper path a const string

2017-01-19T11:45:33+00:00

This is in preparation for making it so that usermode helper programs can't be changed, if desired, by userspace. We will tackle the mess of cleaning up the write-ability of argv and env later, that's going to take more work, for much less gain... Signed-off-by: Greg Kroah-Hartman

kmod: use system_unbound_wq instead of khelper

2015-09-10T20:29:01+00:00

We need to launch the usermodehelper kernel threads with the widest affinity and this is partly why we use khelper. This workqueue has unbound properties and thus a wide affinity inherited by all its children. Now khelper also has special properties that we aren't much interested in: ordered and singlethread. There is really no need about ordering as all we do is creating kernel threads. This can be done concurrently. And singlethread is a useless limitation as well. The workqueue engine already proposes generic unbound workqueues that don't share these useless properties and handle well parallel jobs. The only worrysome specific is their affinity to the node of the current CPU. It's fine for creating the usermodehelper kernel threads but those inherit this affinity for longer jobs such as requesting modules. This patch proposes to use these node affine unbound workqueues assuming that a node is sufficient to handle several parallel usermodehelper requests. Signed-off-by: Frederic Weisbecker Cc: Rik van Riel Reviewed-by: Oleg Nesterov Cc: Christoph Lameter Cc: Tejun Heo Cc: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kmod: remove call_usermodehelper_fns()

2013-05-01T00:04:06+00:00

This function suffers from not being able to determine if the cleanup is called in case it returns -ENOMEM. Nobody is using it anymore, so let's remove it. Signed-off-by: Lucas De Marchi Cc: Oleg Nesterov Cc: David Howells Cc: James Morris Cc: Al Viro Cc: Tejun Heo Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

usermodehelper: export call_usermodehelper_exec() and call_usermodehelper_setup()

2013-05-01T00:04:05+00:00

call_usermodehelper_setup() + call_usermodehelper_exec() need to be called instead of call_usermodehelper_fns() when the cleanup function needs to be called even when an ENOMEM error occurs. In this case using call_usermodehelper_fns() the user can't distinguish if the cleanup function was called or not. [akpm@linux-foundation.org: export call_usermodehelper_setup() to modules] Signed-off-by: Lucas De Marchi Reviewed-by: Oleg Nesterov Cc: David Howells Cc: James Morris Cc: Al Viro Cc: Tejun Heo Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kmod: move call_usermodehelper_fns() to .c file and unexport all it's helpers

2012-06-01T00:49:28+00:00

If we move call_usermodehelper_fns() to kmod.c file and EXPORT_SYMBOL it we can avoid exporting all it's helper functions: call_usermodehelper_setup call_usermodehelper_setfns call_usermodehelper_exec And make all of them static to kmod.c Since the optimizer will see all these as a single call site it will inline them inside call_usermodehelper_fns(). So we loose the call to _fns but gain 3 calls to the helpers. (Not that it matters) Signed-off-by: Boaz Harrosh Cc: Oleg Nesterov Cc: Tetsuo Handa Cc: Ingo Molnar Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kmod: unexport call_usermodehelper_freeinfo()

2012-06-01T00:49:28+00:00

call_usermodehelper_freeinfo() is not used outside of kmod.c. So unexport it, and make it static to kmod.c Signed-off-by: Boaz Harrosh Cc: Oleg Nesterov Cc: Tetsuo Handa Cc: Ingo Molnar Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

PM / Sleep: Mitigate race between the freezer and request_firmware()

2012-03-28T21:30:28+00:00

There is a race condition between the freezer and request_firmware() such that if request_firmware() is run on one CPU and freeze_processes() is run on another CPU and usermodehelper_disable() called by it succeeds to grab umhelper_sem for writing before usermodehelper_read_trylock() called from request_firmware() acquires it for reading, the request_firmware() will fail and trigger a WARN_ON() complaining that it was called at a wrong time. However, in fact, it wasn't called at a wrong time and freeze_processes() simply happened to be executed simultaneously. To avoid this race, at least in some cases, modify usermodehelper_read_trylock() so that it doesn't fail if the freezing of tasks has just started and hasn't been completed yet. Instead, during the freezing of tasks, it will try to freeze the task that has called it so that it can wait until user space is thawed without triggering the scary warning. For this purpose, change usermodehelper_disabled so that it can take three different values, UMH_ENABLED (0), UMH_FREEZING and UMH_DISABLED. The first one means that usermode helpers are enabled, the last one means "hard disable" (i.e. the system is not ready for usermode helpers to be used) and the second one is reserved for the freezer. Namely, when freeze_processes() is started, it sets usermodehelper_disabled to UMH_FREEZING which tells usermodehelper_read_trylock() that it shouldn't fail just yet and should call try_to_freeze() if woken up and cannot return immediately. This way all freezable tasks that happen to call request_firmware() right before freeze_processes() is started and lose the race for umhelper_sem with it will be frozen and will sleep until thaw_processes() unsets usermodehelper_disabled. [For the non-freezable callers of request_firmware() the race for umhelper_sem against freeze_processes() is unfortunately unavoidable.] Reported-by: Stephen Boyd Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Cc: stable@vger.kernel.org