Commit graph

26 commits

Author SHA1 Message Date
Jim Cromie
b7b4eebdba dyndbg: gather __dyndbg[] state into struct _ddebug_info
This new struct composes the linker provided (vector,len) section,
and provides a place to add other __dyndbg[] state-data later:

  descs - the vector of descriptors in __dyndbg section.
  num_descs - length of the data/section.

Use it, in several different ways, as follows:

In lib/dynamic_debug.c:

ddebug_add_module(): Alter params-list, replacing 2 args (array,index)
with a struct _ddebug_info * containing them both, with room for
expansion.  This helps future-proof the function prototype against the
looming addition of class-map info into the dyndbg-state, by providing
a place to add more member fields later.

NB: later add static struct _ddebug_info builtins_state declaration,
not needed yet.

ddebug_add_module() is called in 2 contexts:

In dynamic_debug_init(), declare, init a struct _ddebug_info di
auto-var to use as a cursor.  Then iterate over the prdbg blocks of
the builtin modules, and update the di cursor before calling
_add_module for each.

Its called from kernel/module/main.c:load_info() for each loaded
module:

In internal.h, alter struct load_info, replacing the dyndbg array,len
fields with an embedded _ddebug_info containing them both; and
populate its members in find_module_sections().

The 2 calling contexts differ in that _init deals with contiguous
subranges of __dyndbgs[] section, packed together, while loadable
modules are added one at a time.

So rename ddebug_add_module() into outer/__inner fns, call __inner
from _init, and provide the offset into the builtin __dyndbgs[] where
the module's prdbgs reside.  The cursor provides start, len of the
subrange for each.  The offset will be used later to pack the results
of builtin __dyndbg_sites[] de-duplication, and is 0 and unneeded for
loadable modules,

Note:

kernel/module/main.c includes <dynamic_debug.h> for struct
_ddeubg_info.  This might be prone to include loops, since its also
included by printk.h.  Nothing has broken in robot-land on this.

cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20220904214134.408619-12-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-07 17:04:48 +02:00
Aaron Tomlin
17dd25c29c module: Modify module_flags() to accept show_state argument
No functional change.

With this patch a given module's state information (i.e. 'mod->state')
can be omitted from the specified buffer. Please note that this is in
preparation to include the last unloaded module's taint flag(s),
if available.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-07-14 17:40:23 -07:00
Christophe Leroy
cfa94c538b module: Fix selfAssignment cppcheck warning
cppcheck reports the following warnings:

kernel/module/main.c:1455:26: warning: Redundant assignment of 'mod->core_layout.size' to itself. [selfAssignment]
   mod->core_layout.size = strict_align(mod->core_layout.size);
                         ^
kernel/module/main.c:1489:26: warning: Redundant assignment of 'mod->init_layout.size' to itself. [selfAssignment]
   mod->init_layout.size = strict_align(mod->init_layout.size);
                         ^
kernel/module/main.c:1493:26: warning: Redundant assignment of 'mod->init_layout.size' to itself. [selfAssignment]
   mod->init_layout.size = strict_align(mod->init_layout.size);
                         ^
kernel/module/main.c:1504:26: warning: Redundant assignment of 'mod->init_layout.size' to itself. [selfAssignment]
   mod->init_layout.size = strict_align(mod->init_layout.size);
                         ^
kernel/module/main.c:1459:26: warning: Redundant assignment of 'mod->data_layout.size' to itself. [selfAssignment]
   mod->data_layout.size = strict_align(mod->data_layout.size);
                         ^
kernel/module/main.c:1463:26: warning: Redundant assignment of 'mod->data_layout.size' to itself. [selfAssignment]
   mod->data_layout.size = strict_align(mod->data_layout.size);
                         ^
kernel/module/main.c:1467:26: warning: Redundant assignment of 'mod->data_layout.size' to itself. [selfAssignment]
   mod->data_layout.size = strict_align(mod->data_layout.size);
                         ^

This is due to strict_align() being a no-op when
CONFIG_STRICT_MODULE_RWX is not selected.

Transform strict_align() macro into an inline function. It will
allow type checking and avoid the selfAssignment warning.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-07-01 14:44:17 -07:00
Aaron Tomlin
99bd995655 module: Introduce module unload taint tracking
Currently, only the initial module that tainted the kernel is
recorded e.g. when an out-of-tree module is loaded.

The purpose of this patch is to allow the kernel to maintain a record of
each unloaded module that taints the kernel. So, in addition to
displaying a list of linked modules (see print_modules()) e.g. in the
event of a detected bad page, unloaded modules that carried a taint/or
taints are displayed too. A tainted module unload count is maintained.

The number of tracked modules is not fixed. This feature is disabled by
default.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-05-12 10:29:41 -07:00
Aaron Tomlin
6fb0538d01 module: Move module_assert_mutex_or_preempt() to internal.h
No functional change.

This patch migrates module_assert_mutex_or_preempt() to internal.h.
So, the aforementiond function can be used outside of main/or core
module code yet will remain restricted for internal use only.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-05-12 10:29:41 -07:00
Aaron Tomlin
c14e522bc7 module: Make module_flags_taint() accept a module's taints bitmap and usable outside core code
No functional change.

The purpose of this patch is to modify module_flags_taint() to accept
a module's taints bitmap as a parameter and modifies all users
accordingly. Furthermore, it is now possible to access a given
module's taint flags data outside of non-essential code yet does
remain for internal use only.

This is in preparation for module unload taint tracking support.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-05-12 10:29:41 -07:00
Christophe Leroy
01dc0386ef module: Add CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
Add CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC to allow architectures
to request having modules data in vmalloc area instead of module area.

This is required on powerpc book3s/32 in order to set data non
executable, because it is not possible to set executability on page
basis, this is done per 256 Mbytes segments. The module area has exec
right, vmalloc area has noexec.

This can also be useful on other powerpc/32 in order to maximize the
chance of code being close enough to kernel core to avoid branch
trampolines.

Cc: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mcgrof: rebased in light of kernel/module/kdb.c move]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:05 -07:00
Christophe Leroy
6ab9942c44 module: Introduce data_layout
In order to allow separation of data from text, add another layout,
called data_layout. For architectures requesting separation of text
and data, only text will go in core_layout and data will go in
data_layout.

For architectures which keep text and data together, make data_layout
an alias of core_layout, that way data_layout can be used for all
data manipulations, regardless of whether data is in core_layout or
data_layout.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:05 -07:00
Christophe Leroy
446d55666d module: Prepare for handling several RB trees
In order to separate text and data, we need to setup
two rb trees.

Modify functions to give the tree as a parameter.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:05 -07:00
Christophe Leroy
80b8bf4369 module: Always have struct mod_tree_root
In order to separate text and data, we need to setup
two rb trees.

This means that struct mod_tree_root is required even without
MODULES_TREE_LOOKUP.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Aaron Tomlin <atomlin@atomlin.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:05 -07:00
Christophe Leroy
7337f929d5 module: Rename debug_align() as strict_align()
debug_align() was added by commit 84e1c6bb38 ("x86: Add RO/NX
protection for loadable kernel modules")

At that time the config item was CONFIG_DEBUG_SET_MODULE_RONX.

But nowadays it has changed to CONFIG_STRICT_MODULE_RWX and
debug_align() is confusing because it has nothing to do with
DEBUG.

Rename it strict_align()

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Christophe Leroy
ef505058dc module: Rework layout alignment to avoid BUG_ON()s
Perform layout alignment verification up front and WARN_ON()
and fail module loading instead of crashing the machine.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Christophe Leroy
32a08c17d8 module: Move module_enable_x() and frob_text() in strict_rwx.c
Move module_enable_x() together with module_enable_nx() and
module_enable_ro().

Those three functions are going together, they are all used
to set up the correct page flags on the different sections.

As module_enable_x() is used independently of
CONFIG_STRICT_MODULE_RWX, build strict_rwx.c all the time and
use IS_ENABLED(CONFIG_STRICT_MODULE_RWX) when relevant.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Christophe Leroy
0597579356 module: Make module_enable_x() independent of CONFIG_ARCH_HAS_STRICT_MODULE_RWX
module_enable_x() has nothing to do with CONFIG_ARCH_HAS_STRICT_MODULE_RWX
allthough by coincidence architectures who need module_enable_x() are
selection CONFIG_ARCH_HAS_STRICT_MODULE_RWX.

Enable module_enable_x() for everyone everytime. If an architecture
already has module text set executable, it's a no-op.

Don't check text_size alignment. When CONFIG_STRICT_MODULE_RWX is set
the verification is already done in frob_rodata(). When
CONFIG_STRICT_MODULE_RWX is not set it is not a big deal to have the
start of data as executable. Just make sure we entirely get the last
page when the boundary is not aligned.

And don't BUG on misaligned base as some architectures like nios2
use kmalloc() for allocating modules. So just bail out in that case.
If that's a problem, a page fault will occur later anyway.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Aaron Tomlin
47889798da module: Move version support into a separate file
No functional change.

This patch migrates module version support out of core code into
kernel/module/version.c. In addition simple code refactoring to
make this possible.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Aaron Tomlin
44c09535de module: Move sysfs support into a separate file
No functional change.

This patch migrates module sysfs support out of core code into
kernel/module/sysfs.c. In addition simple code refactoring to
make this possible.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Aaron Tomlin
0ffc40f6c8 module: Move procfs support into a separate file
No functional change.

This patch migrates code that allows one to generate a
list of loaded/or linked modules via /proc when procfs
support is enabled into kernel/module/procfs.c.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Aaron Tomlin
91fb02f315 module: Move kallsyms support into a separate file
No functional change.

This patch migrates kallsyms code out of core module
code kernel/module/kallsyms.c

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Aaron Tomlin
473c84d185 module: Move kmemleak support to a separate file
No functional change.

This patch migrates kmemleak code out of core module
code into kernel/module/debug_kmemleak.c

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Aaron Tomlin
0c1e42805c module: Move extra signature support out of core code
No functional change.

This patch migrates additional module signature check
code from core module code into kernel/module/signing.c.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Aaron Tomlin
b33465fe9c module: Move strict rwx support to a separate file
No functional change.

This patch migrates code that makes module text
and rodata memory read-only and non-text memory
non-executable from core module code into
kernel/module/strict_rwx.c.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Aaron Tomlin
58d208de3e module: Move latched RB-tree support to a separate file
No functional change.

This patch migrates module latched RB-tree support
(e.g. see __module_address()) from core module code
into kernel/module/tree_lookup.c.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Aaron Tomlin
1be9473e31 module: Move livepatch support to a separate file
No functional change.

This patch migrates livepatch support (i.e. used during module
add/or load and remove/or deletion) from core module code into
kernel/module/livepatch.c. At the moment it contains code to
persist Elf information about a given livepatch module, only.
The new file was added to MAINTAINERS.

Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:43:04 -07:00
Aaron Tomlin
5aff4dfdb4 module: Make internal.h and decompress.c more compliant
This patch will address the following warning and style violations
generated by ./scripts/checkpatch.pl in strict mode:

  WARNING: Use #include <linux/module.h> instead of <asm/module.h>
  #10: FILE: kernel/module/internal.h:10:
  +#include <asm/module.h>

  CHECK: spaces preferred around that '-' (ctx:VxV)
  #18: FILE: kernel/module/internal.h:18:
  +#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))

  CHECK: Please use a blank line after function/struct/union/enum declarations
  #69: FILE: kernel/module/internal.h:69:
  +}
  +static inline void module_decompress_cleanup(struct load_info *info)
						   ^
  CHECK: extern prototypes should be avoided in .h files
  #84: FILE: kernel/module/internal.h:84:
  +extern int mod_verify_sig(const void *mod, struct load_info *info);

  WARNING: Missing a blank line after declarations
  #116: FILE: kernel/module/decompress.c:116:
  +               struct page *page = module_get_next_page(info);
  +               if (!page) {

  WARNING: Missing a blank line after declarations
  #174: FILE: kernel/module/decompress.c:174:
  +               struct page *page = module_get_next_page(info);
  +               if (!page) {

  CHECK: Please use a blank line after function/struct/union/enum declarations
  #258: FILE: kernel/module/decompress.c:258:
  +}
  +static struct kobj_attribute module_compression_attr = __ATTR_RO(compression);

Note: Fortunately, the multiple-include optimisation found in
include/linux/module.h will prevent duplication/or inclusion more than
once.

Fixes: f314dfea16 ("modsign: log module name in the event of an error")
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:42:35 -07:00
Aaron Tomlin
8ab4ed08a2 module: Simple refactor in preparation for split
No functional change.

This patch makes it possible to move non-essential code
out of core module code.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:41:13 -07:00
Aaron Tomlin
cfc1d27789 module: Move all into module/
No functional changes.

This patch moves all module related code into a separate directory,
modifies each file name and creates a new Makefile. Note: this effort
is in preparation to refactor core module code.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-04 12:57:54 -07:00
Renamed from kernel/module-internal.h (Browse further)