299 Commits
Author SHA1 Message Date
Mike Rapoport (Microsoft) 0c133b1e78 module: prepare to handle ROX allocations for text
In order to support ROX allocations for module text, it is necessary to
handle modifications to the code, such as relocations and alternatives
patching, without write access to that memory.

One option is to use text patching, but this would make module loading
extremely slow and will expose executable code that is not finally formed.

A better way is to have memory allocated with ROX permissions contain
invalid instructions and keep a writable, but not executable copy of the
module text.  The relocations and alternative patches would be done on the
writable copy using the addresses of the ROX memory.  Once the module is
completely ready, the updated text will be copied to ROX memory using text
patching in one go and the writable copy will be freed.

Add support for that to module initialization code and provide necessary
interfaces in execmem.

Link: https://lkml.kernel.org/r/20241023162711.2579610-5-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewd-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: kdevops <kdevops@lists.linux.dev>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Song Liu <song@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:25:15 -08:00
Al Viro 8152f82010 fdget(), more trivial conversions
all failure exits prior to fdget() leave the scope, all matching fdput()
are immediately followed by leaving the scope.

[xfs_ioc_commit_range() chunk moved here as well]

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-11-03 01:28:06 -05:00
Al Viro 05e555642c regularize emptiness checks in fini_module(2) and vfs_dedupe_file_range()
With few exceptions emptiness checks are done as fd_file(...) in boolean
context (usually something like if (!fd_file(f))...); those will be
taken care of later.

However, there's a couple of places where we do those checks as
'store fd_file(...) into a variable, then check if this variable is
NULL' and those are harder to spot.

Get rid of those now.

use fd_empty() instead of extracting file and then checking it for NULL.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-11-03 01:28:06 -05:00
Matthew Maurer 2295cf87ed module: Reformat struct for code style
Using commas to declare struct members makes adding new members to this
struct not as nice with patch management.

Test results linux-modules-kpd succeed [0].

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
[mcgrof: add automated test results from kdevops using KPD ]
Link: https://github.com/linux-kdevops/linux-modules-kpd/actions/runs/11420095343 # [0]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-19 15:02:00 -07:00
Matthew Maurer d979e3dffa module: Additional validation in elf_validity_cache_strtab
Validate properties of the strtab that are depended on elsewhere, but
were previously unchecked:
* String table nonempty (offset 0 is valid)
* String table has a leading NUL (offset 0 corresponds to "")
* String table is NUL terminated (strfoo functions won't run out of the
  table while reading).
* All symbols names are inbounds of the string table.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-19 14:35:07 -07:00
Matthew Maurer 837031e052 module: Factor out elf_validity_cache_strtab
This patch only moves the existing strtab population to a function.
Validation comes in a following patch, this is split out to make the new
validation checks more clearly separated.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-19 14:35:07 -07:00
Matthew Maurer f3f561218b module: Group section index calculations together
Group all the index detection together to make the parent function
easier to read.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-19 14:35:07 -07:00
Matthew Maurer 0a93953344 module: Factor out elf_validity_cache_index_str
Pull out index validation for the symbol string section.

Note that this does not validate the *contents* of the string table,
only shape and presence of the section.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-19 14:35:07 -07:00
Matthew Maurer 9bd4982cf7 module: Factor out elf_validity_cache_index_sym
Centralize symbol table detection and property validation.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-19 14:35:07 -07:00
Matthew Maurer 0be41a9367 module: Factor out elf_validity_cache_index_mod
Centralize .gnu.linkonce.this_module detection and property validation.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-19 14:35:07 -07:00
Matthew Maurer fbc0e4e482 module: Factor out elf_validity_cache_index_info
Centralize .modinfo detection and property validation.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-19 14:35:07 -07:00
Matthew Maurer 3c5700aeab module: Factor out elf_validity_cache_secstrings
Factor out the validation of section names.

There are two behavioral changes:

1. Previously, we did not validate non-SHF_ALLOC sections.
   This may have once been safe, as find_sec skips non-SHF_ALLOC
   sections, but find_any_sec, which will be used to load BTF if that is
   enabled, ignores the SHF_ALLOC flag. Since there's no need to support
   invalid section names, validate all of them, not just SHF_ALLOC
   sections.
2. Section names were validated *after* accessing them for the purposes
   of detecting ".modinfo" and ".gnu.linkonce.this_module". They are now
   checked prior to the access, which could avoid bad accesses with
   malformed modules.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-19 14:35:07 -07:00
Matthew Maurer c92aab819d module: Factor out elf_validity_cache_sechdrs
Factor out and document the validation of section headers.

Because we now validate all section offsets and lengths before accessing
them, we can remove the ad-hoc checks.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-19 14:35:07 -07:00
Matthew Maurer 90f8f312db module: Factor out elf_validity_ehdr
Factor out verification of the ELF header and document what is checked.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-19 14:35:06 -07:00
Matthew Maurer f439221621 module: Take const arg in validate_section_offset
`validate_section_offset` doesn't modify the info passed in. Make this
clear by adjusting the type signature.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-10-19 14:35:06 -07:00
Al Viro be5498cac2 remove pointless includes of <linux/fdtable.h>
some of those used to be needed, some had been cargo-culted for
no reason...

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-10-07 13:34:41 -04:00
Linus Torvalds 6f81a446f8 Merge tag 'modules-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull module updates from Luis Chamberlain:
 "There are a few fixes / cleanups from Vincent, Chunhui, and Petr, but
  the most important part of this pull request is the Rust community
  stepping up to help maintain both C / Rust code for future Rust module
  support. We grow the set of modules maintainers by three now, and with
  this hope to scale to help address what's needed to properly support
  future Rust module support.

  A lot of exciting stuff coming in future kernel releases.

  This has been on linux-next for ~ 3 weeks now with no issues"

* tag 'modules-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  module: Refine kmemleak scanned areas
  module: abort module loading when sysfs setup suffer errors
  MAINTAINERS: scale modules with more reviewers
  module: Clean up the description of MODULE_SIG_<type>
  module: Split modules_install compression and in-kernel decompression
2024-09-28 09:06:15 -07:00
Linus Torvalds 1f9c4a9967 Kbuild: make MODVERSIONS support depend on not being a compile test build
Currently the Rust support is gated on not having MODVERSIONS enabled,
and as a result an "allmodconfig" build will disable Rust build tests.

While MODVERSIONS configurations are worth build testing, the feature is
not actually meaningful unless you run the result, and I'd rather get
build coverage of Rust than MODVERSIONS.  So let's disable MODVERSIONS
for build testing until the Rust side clears up.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-09-25 11:08:28 -07:00
Linus Torvalds f8ffbc365f Merge tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull 'struct fd' updates from Al Viro:
 "Just the 'struct fd' layout change, with conversion to accessor
  helpers"

* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  add struct fd constructors, get rid of __to_fd()
  struct fd: representation change
  introduce fd_file(), convert all accessors to it.
2024-09-23 09:35:36 -07:00
Linus Torvalds 5ba202a7c9 Merge tag 'x86-build-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 build updates from Thomas Gleixner:
 "Updates for KCOV instrumentation on x86:

   - Prevent spurious KCOV coverage in common_interrupt()

   - Fixup the KCOV Makefile directive which got stale due to a source
     file rename

   - Exclude stack unwinding from KCOV as it creates large amounts of
     uninteresting coverage

   - Provide a self test to validate that KCOV coverage of the interrupt
     handling code starts not before preempt count got updated"

* tag 'x86-build-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Ignore stack unwinding in KCOV
  module: Fix KCOV-ignored file name
  kcov: Add interrupt handling self test
  x86/entry: Remove unwanted instrumentation in common_interrupt()
2024-09-17 12:40:34 +02:00
Vincent Donnefort b319cea805 module: Refine kmemleak scanned areas
commit ac3b432839 ("module: replace module_layout with module_memory")
introduced a set of memory regions for the module layout sharing the
same attributes. However, it didn't update the kmemleak scanned areas
which intended to limit kmemleak scan to sections containing writable
data. This means sections such as .text and .rodata are scanned by
kmemleak.

Refine the scanned areas for modules by limiting it to MOD_TEXT and
MOD_INIT_TEXT mod_mem regions.

CC: Song Liu <song@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-09-13 09:55:17 -07:00
Chunhui Li ce47f7cbbc module: abort module loading when sysfs setup suffer errors
When insmod a kernel module, if fails in add_notes_attrs or
add_sysfs_attrs such as memory allocation fail, mod_sysfs_setup
will still return success, but we can't access user interface
on android device.

Patch for make mod_sysfs_setup can check the error of
add_notes_attrs and add_sysfs_attrs

[mcgrof: the section stuff comes from linux history.git [0]]
Fixes: 3f7b0672086b ("Module section offsets in /sys/module") [0]
Fixes: 6d76013381 ("Add /sys/module/name/notes")
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409010016.3XIFSmRA-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202409072018.qfEzZbO7-lkp@intel.com/
Link: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=3f7b0672086b97b2d7f322bdc289cbfa203f10ef [0]
Signed-off-by: Xion Wang <xion.wang@mediatek.com>
Signed-off-by: Chunhui Li <chunhui.li@mediatek.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-09-13 09:55:17 -07:00
Petr Pavlu f94ce04e54 module: Clean up the description of MODULE_SIG_<type>
The MODULE_SIG_<type> config choice has an inconsistent prompt styled as
a question and lengthy option names.

Simplify the prompt and option names to be consistent with other module
options.

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-08-19 15:11:20 -07:00
Petr Pavlu c7ff693fa2 module: Split modules_install compression and in-kernel decompression
The kernel configuration allows specifying a module compression mode. If
one is selected then each module gets compressed during
'make modules_install' and additionally one can also enable support for
a respective direct in-kernel decompression support. This means that the
decompression support cannot be enabled without the automatic compression.

Some distributions, such as the (open)SUSE family, use a signer service for
modules. A build runs on a worker machine but signing is done by a separate
locked-down server that is in possession of the signing key. The build
invokes 'make modules_install' to create a modules tree, collects
information about the modules, asks the signer service for their signature,
appends each signature to the respective module and compresses all modules.

When using this arrangment, the 'make modules_install' step produces
unsigned+uncompressed modules and the distribution's own build recipe takes
care of signing and compression later.

The signing support can be currently enabled without automatically signing
modules during 'make modules_install'. However, the in-kernel decompression
support can be selected only after first enabling automatic compression
during this step.

To allow only enabling the in-kernel decompression support without the
automatic compression during 'make modules_install', separate the
compression options similarly to the signing options, as follows:

> Enable loadable module support
[*] Module compression
      Module compression type (GZIP)  --->
[*]   Automatically compress all modules
[ ]   Support in-kernel module decompression

* "Module compression" (MODULE_COMPRESS) is a new main switch for the
  compression/decompression support. It replaces MODULE_COMPRESS_NONE.
* "Module compression type" (MODULE_COMPRESS_<type>) chooses the
  compression type, one of GZ, XZ, ZSTD.
* "Automatically compress all modules" (MODULE_COMPRESS_ALL) is a new
  option to enable module compression during 'make modules_install'. It
  defaults to Y.
* "Support in-kernel module decompression" (MODULE_DECOMPRESS) enables
  in-kernel decompression.

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-08-19 15:11:20 -07:00
Al Viro 1da91ea87a introduce fd_file(), convert all accessors to it.
For any changes of struct fd representation we need to
turn existing accesses to fields into calls of wrappers.
Accesses to struct fd::flags are very few (3 in linux/file.h,
1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in
explicit initializers).
	Those can be dealt with in the commit converting to
new layout; accesses to struct fd::file are too many for that.
	This commit converts (almost) all of f.file to
fd_file(f).  It's not entirely mechanical ('file' is used as
a member name more than just in struct fd) and it does not
even attempt to distinguish the uses in pointer context from
those in boolean context; the latter will be eventually turned
into a separate helper (fd_empty()).

	NOTE: mass conversion to fd_empty(), tempting as it
might be, is a bad idea; better do that piecewise in commit
that convert from fdget...() to CLASS(...).

[conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c
caught by git; fs/stat.c one got caught by git grep]
[fs/xattr.c conflict]

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-08-12 22:00:43 -04:00