linux-toradex.git/kernel/module.c, branch v5.3-rc2

Merge tag 'modules-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

2019-07-18T19:06:57+00:00

Pull module updates from Jessica Yu:
 "Summary of modules changes for the 5.3 merge window:

   - Code fixes and cleanups

   - Fix bug where set_memory_x() wasn't being called when rodata=n

   - Fix bug where -EEXIST was being returned for going modules

   - Allow arches to override module_exit_section()"

* tag 'modules-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  modules: fix compile error if don't have strict module rwx
  ARM: module: recognize unwind exit sections
  module: allow arch overrides for .exit section names
  modules: fix BUG when load module with rodata=n
  kernel/module: Fix mem leak in module_add_modinfo_attrs
  kernel: module: Use struct_size() helper
  kernel/module.c: Only return -EEXIST for modules that have finished loading

Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

2019-06-28T17:46:47+00:00

Pull rcu/next + tools/memory-model changes from Paul E. McKenney:

 - RCU flavor consolidation cleanups and optmizations
 - Documentation updates
 - Miscellaneous fixes
 - SRCU updates
 - RCU-sync flavor consolidation
 - Torture-test updates
 - Linux-kernel memory-consistency-model updates, most notably the addition of plain C-language accesses

Signed-off-by: Ingo Molnar

modules: fix compile error if don't have strict module rwx

2019-06-26T17:27:59+00:00

If CONFIG_ARCH_HAS_STRICT_MODULE_RWX is not defined,
we need stub for module_enable_nx() and module_enable_x().

If CONFIG_ARCH_HAS_STRICT_MODULE_RWX is defined, but
CONFIG_STRICT_MODULE_RWX is disabled, we need stub for
module_enable_nx.

Move frob_text() outside of the CONFIG_STRICT_MODULE_RWX,
because it is needed anyway.

Fixes: 2eef1399a866 ("modules: fix BUG when load module with rodata=n")
Signed-off-by: Yang Yingliang 
Signed-off-by: Jessica Yu

module: allow arch overrides for .exit section names

2019-06-24T12:00:32+00:00

Some archs like ARM store unwind information for .exit.text in sections
with unusual names. As this unwind information refers to .exit.text, it
must not be loaded when .exit.text is not loaded (when CONFIG_MODULE_UNLOAD
is unset); otherwise, loading a module can fail due to relocation failures.

Signed-off-by: Matthias Schiffer 
Signed-off-by: Jessica Yu

modules: fix BUG when load module with rodata=n

2019-06-24T10:11:41+00:00

When loading a module with rodata=n, it causes an executing
NX-protected page BUG.

[   32.379191] kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
[   32.382917] BUG: unable to handle page fault for address: ffffffffc0005000
[   32.385947] #PF: supervisor instruction fetch in kernel mode
[   32.387662] #PF: error_code(0x0011) - permissions violation
[   32.389352] PGD 240c067 P4D 240c067 PUD 240e067 PMD 421a52067 PTE 8000000421a53063
[   32.391396] Oops: 0011 [#1] SMP PTI
[   32.392478] CPU: 7 PID: 2697 Comm: insmod Tainted: G           O      5.2.0-rc5+ #202
[   32.394588] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[   32.398157] RIP: 0010:ko_test_init+0x0/0x1000 [ko_test]
[   32.399662] Code: Bad RIP value.
[   32.400621] RSP: 0018:ffffc900029f3ca8 EFLAGS: 00010246
[   32.402171] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[   32.404332] RDX: 00000000000004c7 RSI: 0000000000000cc0 RDI: ffffffffc0005000
[   32.406347] RBP: ffffffffc0005000 R08: ffff88842fbebc40 R09: ffffffff810ede4a
[   32.408392] R10: ffffea00108e3480 R11: 0000000000000000 R12: ffff88842bee21a0
[   32.410472] R13: 0000000000000001 R14: 0000000000000001 R15: ffffc900029f3e78
[   32.412609] FS:  00007fb4f0c0a700(0000) GS:ffff88842fbc0000(0000) knlGS:0000000000000000
[   32.414722] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   32.416290] CR2: ffffffffc0004fd6 CR3: 0000000421a90004 CR4: 0000000000020ee0
[   32.418471] Call Trace:
[   32.419136]  do_one_initcall+0x41/0x1df
[   32.420199]  ? _cond_resched+0x10/0x40
[   32.421433]  ? kmem_cache_alloc_trace+0x36/0x160
[   32.422827]  do_init_module+0x56/0x1f7
[   32.423946]  load_module+0x1e67/0x2580
[   32.424947]  ? __alloc_pages_nodemask+0x150/0x2c0
[   32.426413]  ? map_vm_area+0x2d/0x40
[   32.427530]  ? __vmalloc_node_range+0x1ef/0x260
[   32.428850]  ? __do_sys_init_module+0x135/0x170
[   32.430060]  ? _cond_resched+0x10/0x40
[   32.431249]  __do_sys_init_module+0x135/0x170
[   32.432547]  do_syscall_64+0x43/0x120
[   32.433853]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Because if rodata=n, set_memory_x() can't be called, fix this by
calling set_memory_x in complete_formation();

Fixes: f2c65fb3221a ("x86/modules: Avoid breaking W^X while loading modules")
Suggested-by: Jian Cheng 
Reviewed-by: Nadav Amit 
Signed-off-by: Yang Yingliang 
Signed-off-by: Jessica Yu

kernel/module: Fix mem leak in module_add_modinfo_attrs

2019-06-14T07:31:09+00:00

In module_add_modinfo_attrs if sysfs_create_file
fails, we forget to free allocated modinfo_attrs
and roll back the sysfs files.

Fixes: 03e88ae1b13d ("[PATCH] fix module sysfs files reference counting")
Reviewed-by: Miroslav Benes 
Signed-off-by: YueHaibing 
Signed-off-by: Jessica Yu

kernel: module: Use struct_size() helper

2019-06-07T08:56:32+00:00

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct module_sect_attrs {
	...
        struct module_sect_attr attrs[0];
};

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

So, replace the following form:

sizeof(*sect_attrs) + nloaded * sizeof(sect_attrs->attrs[0]

with:

struct_size(sect_attrs, attrs, nloaded)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva 
Signed-off-by: Jessica Yu

kernel/module.c: Only return -EEXIST for modules that have finished loading

2019-06-05T07:53:24+00:00

Microsoft HyperV disables the X86_FEATURE_SMCA bit on AMD systems, and
linux guests boot with repeated errors:

amd64_edac_mod: Unknown symbol amd_unregister_ecc_decoder (err -2)
amd64_edac_mod: Unknown symbol amd_register_ecc_decoder (err -2)
amd64_edac_mod: Unknown symbol amd_report_gart_errors (err -2)
amd64_edac_mod: Unknown symbol amd_unregister_ecc_decoder (err -2)
amd64_edac_mod: Unknown symbol amd_register_ecc_decoder (err -2)
amd64_edac_mod: Unknown symbol amd_report_gart_errors (err -2)

The warnings occur because the module code erroneously returns -EEXIST
for modules that have failed to load and are in the process of being
removed from the module list.

module amd64_edac_mod has a dependency on module edac_mce_amd.  Using
modules.dep, systemd will load edac_mce_amd for every request of
amd64_edac_mod.  When the edac_mce_amd module loads, the module has
state MODULE_STATE_UNFORMED and once the module load fails and the state
becomes MODULE_STATE_GOING.  Another request for edac_mce_amd module
executes and add_unformed_module() will erroneously return -EEXIST even
though the previous instance of edac_mce_amd has MODULE_STATE_GOING.
Upon receiving -EEXIST, systemd attempts to load amd64_edac_mod, which
fails because of unknown symbols from edac_mce_amd.

add_unformed_module() must wait to return for any case other than
MODULE_STATE_LIVE to prevent a race between multiple loads of
dependent modules.

Signed-off-by: Prarit Bhargava 
Signed-off-by: Barret Rhoden 
Cc: David Arcari 
Cc: Jessica Yu 
Cc: Heiko Carstens 
Signed-off-by: Jessica Yu

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+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
  59 temple place suite 330 boston ma 02111 1307 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 1334 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman

srcu: Allocate per-CPU data for DEFINE_SRCU() in modules

2019-05-28T16:03:35+00:00

Adding DEFINE_SRCU() or DEFINE_STATIC_SRCU() to a loadable module requires
that the size of the reserved region be increased, which is not something
we want to be doing all that often.  One approach would be to require
that loadable modules define an srcu_struct and invoke init_srcu_struct()
from their module_init function and cleanup_srcu_struct() from their
module_exit function.  However, this is more than a bit user unfriendly.

This commit therefore creates an ___srcu_struct_ptrs linker section,
and pointers to srcu_struct structures created by DEFINE_SRCU() and
DEFINE_STATIC_SRCU() within a module are placed into that module's
___srcu_struct_ptrs section.  The required init_srcu_struct() and
cleanup_srcu_struct() functions are then automatically invoked as needed
when that module is loaded and unloaded, thus allowing modules to continue
to use DEFINE_SRCU() and DEFINE_STATIC_SRCU() while avoiding the need
to increase the size of the reserved region.

Many of the algorithms and some of the code was cheerfully cherry-picked
from other code making use of linker sections, perhaps most notably from
tracepoints.  All bugs are nevertheless the sole property of the author.

Suggested-by: Mathieu Desnoyers 
[ paulmck: Use __section() and use "default" in srcu_module_notify()'s
  "switch" statement as suggested by Joel Fernandes. ]
Signed-off-by: Paul E. McKenney 
Tested-by: Joel Fernandes (Google)