linux-toradex.git/kernel/module/internal.h, branch v5.19-rc1

module: Introduce module unload taint tracking

2022-05-12T17:29:41+00:00

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 
Signed-off-by: Luis Chamberlain

module: Move module_assert_mutex_or_preempt() to internal.h

2022-05-12T17:29:41+00:00

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 
Signed-off-by: Luis Chamberlain

module: Make module_flags_taint() accept a module's taints bitmap and usable outside core code

2022-05-12T17:29:41+00:00

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 
Signed-off-by: Luis Chamberlain

module: Add CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC

2022-04-05T15:43:05+00:00

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 
Acked-by: Daniel Thompson 
Cc: Douglas Anderson 
Signed-off-by: Christophe Leroy 
[mcgrof: rebased in light of kernel/module/kdb.c move]
Signed-off-by: Luis Chamberlain

module: Introduce data_layout

2022-04-05T15:43:05+00:00

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 
Signed-off-by: Luis Chamberlain

module: Prepare for handling several RB trees

2022-04-05T15:43:05+00:00

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 
Signed-off-by: Luis Chamberlain

module: Always have struct mod_tree_root

2022-04-05T15:43:05+00:00

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 
Reviewed-by: Aaron Tomlin 
Signed-off-by: Luis Chamberlain

module: Rename debug_align() as strict_align()

2022-04-05T15:43:04+00:00

debug_align() was added by commit 84e1c6bb38eb ("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 
Signed-off-by: Luis Chamberlain

module: Rework layout alignment to avoid BUG_ON()s

2022-04-05T15:43:04+00:00

Perform layout alignment verification up front and WARN_ON()
and fail module loading instead of crashing the machine.

Signed-off-by: Christophe Leroy 
Signed-off-by: Luis Chamberlain

module: Move module_enable_x() and frob_text() in strict_rwx.c

2022-04-05T15:43:04+00:00

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 
Signed-off-by: Luis Chamberlain