7193 Commits

Author SHA1 Message Date
Arnd Bergmann
b2441b3bdc h8300: remove stale bindings and symlink
These four files are left over from the h8300 removal.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-05-20 22:40:56 +02:00
Cristian Ciocaltea
7394d2ebb6 scripts/tags.sh: Invoke 'realpath' via 'xargs'
When COMPILED_SOURCE is set, running

  make ARCH=x86_64 COMPILED_SOURCE=1 cscope tags

could throw the following errors:

scripts/tags.sh: line 98: /usr/bin/realpath: Argument list too long
cscope: no source files found
scripts/tags.sh: line 98: /usr/bin/realpath: Argument list too long
ctags: No files specified. Try "ctags --help".

This is most likely to happen when the kernel is configured to build a
large number of modules, which has the consequence of passing too many
arguments when calling 'realpath' in 'all_compiled_sources()'.

Let's improve this by invoking 'realpath' through 'xargs', which takes
care of properly limiting the argument list.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Link: https://lore.kernel.org/r/20220516234646.531208-1-cristian.ciocaltea@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-19 18:54:40 +02:00
Thomas Gleixner
e020835138 scripts/spdxcheck: Exclude top-level README
Nothing copyrightable to see here.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-18 15:35:42 +02:00
Thomas Gleixner
2ab99ce978 scripts/spdxcheck: Exclude MAINTAINERS/CREDITS
Listings of maintainers and people who deserve credits are not really
interesting in terms of copyright. The usage of these files outside of the
kernel is pointless and the file format is trivial. No point in chasing
them or slapping a SPDX identifier into them just because.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-18 15:35:38 +02:00
Thomas Gleixner
2fb9771336 scripts/spdxcheck: Exclude config directories
Kernel configuration files like default configs are machine generated and
pretty useless outside of the kernel context.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-18 15:35:35 +02:00
Thomas Gleixner
0509b270a3 scripts/spdxcheck: Put excluded files and directories into a separate file
The files and directories which are excluded from scanning are currently
hard coded in the script. That's not maintainable and not accessible for
external tools.

Move the files and directories which should be excluded into a file.  The
default file is scripts/spdxexclude. This can be overridden with the
'-e $FILE' command line option.

The file format and syntax is similar to the .gitignore file.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-18 15:34:33 +02:00
Thomas Gleixner
67924b7141 scripts/spdxcheck: Add option to display files without SPDX
Makes life easier when chasing the missing ones. Is activated with '-f'
on the command line.

# scripts/spdxcheck.py -f kernel/
Files without SPDX:
    ./kernel/cpu.c
    ./kernel/kmod.c
    ./kernel/relay.c
    ./kernel/bpf/offload.c
    ./kernel/bpf/preload/.gitignore
    ./kernel/bpf/preload/iterators/README
    ./kernel/bpf/ringbuf.c
    ./kernel/cgroup/cgroup.c
    ./kernel/cgroup/cpuset.c
    ./kernel/cgroup/legacy_freezer.c
    ./kernel/debug/debug_core.h
    ./kernel/debug/kdb/Makefile
    ./kernel/debug/kdb/kdb_bp.c
    ./kernel/debug/kdb/kdb_bt.c
    ./kernel/debug/kdb/kdb_cmds
    ./kernel/debug/kdb/kdb_debugger.c
    ./kernel/debug/kdb/kdb_io.c
    ./kernel/debug/kdb/kdb_keyboard.c
    ./kernel/debug/kdb/kdb_main.c
    ./kernel/debug/kdb/kdb_private.h
    ./kernel/debug/kdb/kdb_support.c
    ./kernel/locking/lockdep_states.h
    ./kernel/locking/mutex-debug.c
    ./kernel/locking/spinlock_debug.c
    ./kernel/sched/pelt.h

With the optional -D parameter the directory depth can be limited:

# scripts/spdxcheck.py -f -D 0 kernel/
Files without SPDX:
    ./kernel/cpu.c
    ./kernel/kmod.c
    ./kernel/relay.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-18 15:32:38 +02:00
Thomas Gleixner
0e7f030687 scripts/spdxcheck: Add [sub]directory statistics
Add functionality to display [sub]directory statistics. This is enabled by
adding '-d' to the command line. The optional -D parameter allows to limit
the directory depth. If supplied the subdirectories are accumulated

# scripts/spdxcheck.py -d kernel/
Incomplete directories: SPDX in Files
    ./kernel                         :   111 of   114   97%
    ./kernel/bpf                     :    43 of    45   95%
    ./kernel/bpf/preload             :     4 of     5   80%
    ./kernel/bpf/preload/iterators   :     4 of     5   80%
    ./kernel/cgroup                  :    10 of    13   76%
    ./kernel/configs                 :     0 of     9    0%
    ./kernel/debug                   :     3 of     4   75%
    ./kernel/debug/kdb               :     1 of    11    9%
    ./kernel/locking                 :    29 of    32   90%
    ./kernel/sched                   :    38 of    39   97%

The result can be accumulated by restricting the depth via the new command
line option '-d $DEPTH':

# scripts/spdxcheck.py -d -D1
Incomplete directories: SPDX in Files
    ./                               :     6 of    13   46%
    ./Documentation                  :  4096 of  8451   48%
    ./arch                           : 13476 of 16402   82%
    ./block                          :   100 of   101   99%
    ./certs                          :    11 of    14   78%
    ./crypto                         :   145 of   176   82%
    ./drivers                        : 24682 of 30745   80%
    ./fs                             :  1876 of  2110   88%
    ./include                        :  5175 of  5757   89%
    ./ipc                            :    12 of    13   92%
    ./kernel                         :   493 of   527   93%
    ./lib                            :   393 of   524   75%
    ./mm                             :   151 of   159   94%
    ./net                            :  1713 of  1900   90%
    ./samples                        :   211 of   273   77%
    ./scripts                        :   341 of   435   78%
    ./security                       :   241 of   250   96%
    ./sound                          :  2438 of  2503   97%
    ./tools                          :  3810 of  5462   69%
    ./usr                            :     9 of    10   90%

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-18 15:31:45 +02:00
Thomas Gleixner
a377ce75e4 scripts/spdxcheck: Add directory statistics
For better insights.

Directories accounted:     4646
Directories complete:      2565  55%

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-18 15:31:28 +02:00
Thomas Gleixner
149d623fbe scripts/spdxcheck: Add percentage to statistics
Files checked:            75856
Lines checked:           294516
Files with SPDX:          59410  78%
Files with errors:            0

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-18 15:30:49 +02:00
Uros Bizjak
0aa7be05d8 locking/atomic: Add generic try_cmpxchg64 support
Add generic support for try_cmpxchg64{,_acquire,_release,_relaxed}
and their falbacks involving cmpxchg64.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220515184205.103089-2-ubizjak@gmail.com
2022-05-18 00:08:27 +02:00
Heiko Carstens
8218827b73 scripts/min-tool-version.sh: raise minimum clang version to 14.0.0 for s390
Before version 14.0.0 llvm's integrated assembler fails to handle some
displacement variants:

arch/s390/purgatory/head.S:108:10: error: invalid operand for instruction
 lg %r11,kernel_type-.base_crash(%r13)

Instead of working around this and given that this is already fixed
raise the minimum clang version from 13.0.0 to 14.0.0.

Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://reviews.llvm.org/D113341
Link: https://lore.kernel.org/r/20220511120532.2228616-9-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-05-17 15:16:29 +02:00
Kees Cook
710e4ebfba gcc-plugins: randstruct: Remove cast exception handling
With all randstruct exceptions removed, remove all the exception
handling code. Any future warnings are likely to be shared between
this plugin and Clang randstruct, and will need to be addressed in a
more wholistic fashion.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-05-16 16:02:21 -07:00
Kees Cook
b146cbf2e3 af_unix: Silence randstruct GCC plugin warning
While preparing for Clang randstruct support (which duplicated many of
the warnings the randstruct GCC plugin warned about), one strange one
remained only for the randstruct GCC plugin. Eliminating this rids
the plugin of the last exception.

It seems the plugin is happy to dereference individual members of
a cross-struct cast, but it is upset about casting to a whole object
pointer. This only manifests in one place in the kernel, so just replace
the variable with individual member accesses. There is no change in
executable instruction output.

Drop the last exception from the randstruct GCC plugin.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Cong Wang <cong.wang@bytedance.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: netdev@vger.kernel.org
Cc: linux-hardening@vger.kernel.org
Acked-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Link: https://lore.kernel.org/lkml/20220511022217.58586-1-kuniyu@amazon.co.jp
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/lkml/20220511151542.4cb3ff17@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-05-16 16:02:21 -07:00
Kees Cook
2dcfe9e2d3 niu: Silence randstruct warnings
Clang randstruct gets upset when it sees struct addresspace (which is
randomized) being assigned to a struct page (which is not randomized):

drivers/net/ethernet/sun/niu.c:3385:12: error: casting from randomized structure pointer type 'struct address_space *' to 'struct page *'
                        *link = (struct page *) page->mapping;
                                ^

It looks like niu.c is looking for an in-line place to chain its allocated
pages together and is overloading the "mapping" member, as it is unused.
This is very non-standard, and is expected to be cleaned up in the
future[1], but there is no "correct" way to handle it today.

No meaningful machine code changes result after this change, and source
readability is improved.

Drop the randstruct exception now that there is no "confusing" cross-type
assignment.

[1] https://lore.kernel.org/lkml/YnqgjVoMDu5v9PNG@casper.infradead.org/

Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: netdev@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-hardening@vger.kernel.org
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/lkml/20220511151647.7290adbe@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-05-16 16:02:21 -07:00
Kees Cook
c1298a3a11 big_keys: Use struct for internal payload
The randstruct GCC plugin gets upset when it sees struct path (which is
randomized) being assigned from a "void *" (which it cannot type-check).

There's no need for these casts, as the entire internal payload use is
following a normal struct layout. Convert the enum-based void * offset
dereferencing to the new big_key_payload struct. No meaningful machine
code changes result after this change, and source readability is improved.

Drop the randstruct exception now that there is no "confusing" cross-type
assignment.

Cc: David Howells <dhowells@redhat.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-hardening@vger.kernel.org
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-05-16 16:02:21 -07:00
Josh Poimboeuf
1d1a0e7c51 scripts/faddr2line: Fix overlapping text section failures
There have been some recent reports of faddr2line failures:

  $ scripts/faddr2line sound/soundcore.ko sound_devnode+0x5/0x35
  bad symbol size: base: 0x0000000000000000 end: 0x0000000000000000

  $ ./scripts/faddr2line vmlinux.o enter_from_user_mode+0x24
  bad symbol size: base: 0x0000000000005fe0 end: 0x0000000000005fe0

The problem is that faddr2line is based on 'nm', which has a major
limitation: it doesn't know how to distinguish between different text
sections.  So if an offset exists in multiple text sections in the
object, it may fail.

Rewrite faddr2line to be section-aware, by basing it on readelf.

Fixes: 67326666e2d4 ("scripts: add script for translating stack dump function offsets")
Reported-by: Kaiwan N Billimoria <kaiwan.billimoria@gmail.com>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/29ff99f86e3da965b6e46c1cc2d72ce6528c17c3.1652382321.git.jpoimboe@kernel.org
2022-05-12 12:07:11 -07:00
Josh Poimboeuf
21e350233b scripts: Create objdump-func helper script
Add a simple script which disassembles a single function from an object
file.  Comes in handy for objtool warnings and kernel stack traces.

Originally-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/3eb3f091fd6bd9caba50392ceab98ce756804f3b.1650578171.git.jpoimboe@redhat.com
2022-05-12 10:08:43 -07:00
Masahiro Yamada
2a66c3124a modpost: change the license of EXPORT_SYMBOL to bool type
There were more EXPORT_SYMBOL types in the past. The following commits
removed unused ones.

 - f1c3d73e973c ("module: remove EXPORT_SYMBOL_GPL_FUTURE")
 - 367948220fce ("module: remove EXPORT_UNUSED_SYMBOL*")

There are 3 remaining in enum export, but export_unknown does not make
any sense because we never expect such a situation like "we do not know
how it was exported".

If the symbol name starts with "__ksymtab_", but the section name
does not start with "___ksymtab+" or "___ksymtab_gpl+", it is not an
exported symbol.

It occurs when a variable starting with "__ksymtab_" is directly defined:

   int __ksymtab_foo;

Presumably, there is no practical issue for using such a weird variable
name (but there is no good reason for doing so, either).

Anyway, that is not an exported symbol. Setting export_unknown is not
the right thing to do. Do not call sym_add_exported() in this case.

With pointless export_unknown removed, the export type finally becomes
boolean (either EXPORT_SYMBOL or EXPORT_SYMBOL_GPL).

I renamed the field name to is_gpl_only. EXPORT_SYMBOL_GPL sets it true.
Only GPL-compatible modules can use it.

I removed the orphan comment, "How a symbol is exported", which is
unrelated to sec_mismatch_count. It is about enum export.
See commit bd5cbcedf446 ("kbuild: export-type enhancement to modpost.c")

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
2022-05-11 21:46:39 +09:00
Masahiro Yamada
ce79c406a2 modpost: remove left-over cross_compile declaration
This is a remnant of commit 6543becf26ff ("mod/file2alias: make
modalias generation safe for cross compiling").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-11 21:46:39 +09:00
Masahiro Yamada
78e9e56af3 kbuild: record symbol versions in *.cmd files
When CONFIG_MODVERSIONS=y, the output from genksyms is saved in
separate *.symversions files, and will be used much later when
CONFIG_LTO_CLANG=y because it is impossible to update LLVM bit code
here.

This approach is not robust because:

 - *.symversions may or may not exist. If *.symversions does not
   exist, we never know if it is missing for legitimate reason
   (i.e. no EXPORT_SYMBOL) or something bad has happened (for
   example, the user accidentally deleted it). Once it occurs,
   it is not self-healing because *.symversions is generated
   as a side effect.

 - stale (i.e. invalid) *.symversions might be picked up if an
   object is generated in a non-ordinary way, and corresponding
   *.symversions (, which was generated by old builds) just happen
   to exist.

A more robust approach is to save symbol versions in *.cmd files
because:

 - *.cmd always exists (if the object is generated by if_changed
   rule or friends). Even if the user accidentally deletes it,
   it will be regenerated in the next build.

 - *.cmd is always re-generated when the object is updated. This
   avoid stale version information being picked up.

I will remove *.symversions later.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
2022-05-11 21:46:39 +09:00
Masahiro Yamada
e493f47275 kbuild: generate a list of objects in vmlinux
A *.mod file lists the member objects of a module, but vmlinux does
not have such a file.

Generate this list to allow modpost to know all the member objects.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
2022-05-11 21:46:39 +09:00
Masahiro Yamada
a44abaca0e modpost: move *.mod.c generation to write_mod_c_files()
A later commit will add more code to this list_for_each_entry loop.

Before that, move the loop body into a separate helper function.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
2022-05-11 21:46:38 +09:00
Masahiro Yamada
7fedac9698 modpost: merge add_{intree_flag,retpoline,staging_flag} to add_header
add_intree_flag(), add_retpoline(), and add_staging_flag() are small
enough to be merged into add_header().

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
2022-05-11 21:46:38 +09:00
Reza Arbab
5d53508d1b scripts/prune-kernel: Use kernel-install if available
If the new-kernel-pkg utility isn't present, try using kernel-install.
This is what the %preun scriptlet in scripts/package/mkspec does too.

Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-05-11 21:46:38 +09:00
Masahiro Yamada
f774f5bb87 kbuild: factor out the common installation code into scripts/install.sh
Many architectures have similar install.sh scripts.

The first half is really generic; it verifies that the kernel image
and System.map exist, then executes ~/bin/${INSTALLKERNEL} or
/sbin/${INSTALLKERNEL} if available.

The second half is kind of arch-specific; it copies the kernel image
and System.map to the destination, but the code is slightly different.

Factor out the generic part into scripts/install.sh.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
2022-05-11 21:45:53 +09:00
Kees Cook
61f60bac8c gcc-plugins: Change all version strings match kernel
It's not meaningful for the GCC plugins to track their versions separately
from the rest of the kernel. Switch all versions to the kernel version.

Fix mismatched indenting while we're at it.

Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-05-10 16:54:33 -07:00
Kees Cook
035f7f87b7 randstruct: Enable Clang support
Clang 15 will support randstruct via the -frandomize-layout-seed-file=...
option. Update the Kconfig and Makefile to recognize this feature.

Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220503205503.3054173-7-keescook@chromium.org
2022-05-08 01:33:07 -07:00
Kees Cook
be2b34fa9b randstruct: Move seed generation into scripts/basic/
To enable Clang randstruct support, move the structure layout
randomization seed generation out of scripts/gcc-plugins/ into
scripts/basic/ so it happens early enough that it can be used by either
compiler implementation. The gcc-plugin still builds its own header file,
but now does so from the common "randstruct.seed" file.

Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220503205503.3054173-6-keescook@chromium.org
2022-05-08 01:33:07 -07:00
Kees Cook
613f4b3ed7 randstruct: Split randstruct Makefile and CFLAGS
To enable the new Clang randstruct implementation[1], move
randstruct into its own Makefile and split the CFLAGS from
GCC_PLUGINS_CFLAGS into RANDSTRUCT_CFLAGS.

[1] https://reviews.llvm.org/D121556

Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220503205503.3054173-5-keescook@chromium.org
2022-05-08 01:33:06 -07:00
Kees Cook
595b893e20 randstruct: Reorganize Kconfigs and attribute macros
In preparation for Clang supporting randstruct, reorganize the Kconfigs,
move the attribute macros, and generalize the feature to be named
CONFIG_RANDSTRUCT for on/off, CONFIG_RANDSTRUCT_FULL for the full
randomization mode, and CONFIG_RANDSTRUCT_PERFORMANCE for the cache-line
sized mode.

Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220503205503.3054173-4-keescook@chromium.org
2022-05-08 01:33:06 -07:00
Kees Cook
d364658970 sancov: Split plugin build from plugin CFLAGS
When the sancov_plugin is enabled, it gets added to gcc-plugin-y which
is used to populate both GCC_PLUGIN (for building the plugin) and
GCC_PLUGINS_CFLAGS (for enabling and options). Instead of adding sancov
to both and then removing it from GCC_PLUGINS_CFLAGS, create a separate
list, gcc-plugin-external-y, which is only added to GCC_PLUGIN.

This will also be used by the coming randstruct build changes.

Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: linux-kbuild@vger.kernel.org
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220503205503.3054173-3-keescook@chromium.org
2022-05-08 01:33:06 -07:00
Masahiro Yamada
f18379a302 modpost: split new_symbol() to symbol allocation and hash table addition
new_symbol() does two things; allocate a new symbol and register it
to the hash table.

Using a separate function for each is easier to understand.

Replace new_symbol() with hash_add_symbol(). Remove the second parameter
of alloc_symbol().

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:01 +09:00
Masahiro Yamada
e76cc48d8e modpost: make sym_add_exported() always allocate a new symbol
Currently, sym_add_exported() does not allocate a symbol if the same
name symbol already exists in the hash table.

This does not reflect the real use cases. You can let an external
module override the in-tree one. In this case, the external module
will export the same name symbols as the in-tree one. However,
modpost simply ignores those symbols, then Module.symvers for the
external module loses its symbols.

sym_add_exported() should allocate a new symbol.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:01 +09:00
Masahiro Yamada
b842271108 modpost: make multiple export error
This is currently a warning, but I think modpost should stop building
in this case.

If the same symbol is exported multiple times and we let it keep going,
the sanity check becomes difficult.

Only the legitimate case is that an external module overrides the
corresponding in-tree module to provide a different implementation
with the same interface.

Also, there exists an upstream example that exploits this feature.

  $ make M=tools/testing/nvdimm

... builds tools/testing/nvdimm/libnvdimm.ko. This is a mocked module
that overrides the symbols from drivers/nvdimm/libnvdimm.ko.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:01 +09:00
Masahiro Yamada
f841536e8c modpost: dump Module.symvers in the same order of modules.order
modpost dumps the exported symbols into Module.symvers, but currently
in random order because it iterates in the hash table.

Add a linked list of exported symbols in struct module, so we can
iterate on symbols per module.

This commit makes Module.symvers much more readable; the outer loop in
write_dump() iterates over the modules in the order of modules.order,
and the inner loop dumps symbols in each module.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:01 +09:00
Masahiro Yamada
ab489d6002 modpost: traverse the namespace_list in order
Use the doubly linked list to traverse the list in the added order.
This makes the code more consistent.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
4484054816 modpost: use doubly linked list for dump_lists
This looks easier to understand (just because this is a pattern in
the kernel code). No functional change is intended.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
8a69152be9 modpost: traverse unresolved symbols in order
Currently, modpost manages unresolved in a singly linked list; it adds
a new node to the head, and traverses the list from new to old.

Use a doubly linked list to keep the order in the symbol table in the
ELF file.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
e882e89bcf modpost: add sym_add_unresolved() helper
Add a small helper, sym_add_unresolved() to ease the further
refactoring.

Remove the 'weak' argument from alloc_symbol() because it is sensible
only for unresolved symbols.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
325eba05e8 modpost: traverse modules in order
Currently, modpost manages modules in a singly linked list; it adds
a new node to the head, and traverses the list from new to old.

It works, but the error messages are shown in the reverse order.

If you have a Makefile like this:

  obj-m += foo.o bar.o

then, modpost shows error messages in bar.o, foo.o, in this order.

Use a doubly linked list to keep the order in modules.order; use
list_add_tail() for the node addition and list_for_each_entry() for
the list traverse.

Now that the kernel's list macros have been imported to modpost, I will
use them actively going forward.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
97aa4aef53 modpost: import include/linux/list.h
Import include/linux/list.h to use convenient list macros in modpost.

I dropped kernel-space code such as {WRITE,READ}_ONCE etc. and unneeded
macros.

I also imported container_of() from include/linux/container_of.h and
type definitions from include/linux/types.h.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
5066743e4c modpost: change mod->gpl_compatible to bool type
Currently, mod->gpl_compatible is tristate; it is set to -1 by default,
then to 1 or 0 when MODULE_LICENSE() is found.

Maybe, -1 was chosen to represent the 'unknown' license, but it is not
useful.

The current code:

    if (!mod->gpl_compatible)
            check_for_gpl_usage(exp->export, basename, exp->name);

... only cares whether gpl_compatible is zero or not.

Change it to a bool type with the initial value 'true', which has no
functional change.

The default value should be 'true' instead of 'false'.

Since commit 1d6cd3929360 ("modpost: turn missing MODULE_LICENSE() into
error"), unknown module license is an error.

The error message, "missing MODULE_LICENSE()" is enough to explain the
issue. It is not sensible to show another message, "GPL-incompatible
module ... uses GPL-only symbol".

Add comments to explain this.

While I was here, I renamed gpl_compatible to is_gpl_compatible for
clarification, and also slightly refactored the code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
58e01fcae1 modpost: use bool type where appropriate
Use 'bool' to clarify that the valid value is true or false.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
8d613a1d04 kbuild: drop $(objtree)/ prefix support for clean-files
I think this hack is a bad idea. arch/powerpc/boot/Makefile is the
only and last user. Let's stop doing this.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
2022-05-08 03:17:00 +09:00
Masahiro Yamada
70ddb48db4 modpost: move struct namespace_list to modpost.c
There is no good reason to define struct namespace_list in modpost.h

struct module has pointers to struct namespace_list, but that does
not require the definition of struct namespace_list.

Move it to modpost.c.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:17:00 +09:00
Masahiro Yamada
4cae77ac58 modpost: retrieve the module dependency and CRCs in check_exports()
Do not repeat the similar code.

It is simpler to do this in check_exports() instead of add_versions().

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:59 +09:00
Masahiro Yamada
23beb44a0e modpost: add a separate error for exported symbols without definition
It took me a while to understand the intent of "exp->module == mod".

This code goes back to 2003. [1]

The commit is not in this git repository, and might be worth a little
explanation.

You can add EXPORT_SYMBOL() without having its definition in the same
file (but you need to put a declaration).

This is typical when EXPORT_SYMBOL() is added in a C file, but the
actual implementation is in a separate assembly file.

One example is arch/arm/kernel/armksyms.c

In the old days, EXPORT_SYMBOL() was only available in C files (but
this limitation does not exist any more). If you forget to add the
definition, this error occurs.

Add a separate, clearer message for this case. It should be an error
even if KBUILD_MODPOST_WARN is given.

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=2763b6bcb96e6a38a2fe31108fe5759ec5bcc80a

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:59 +09:00
Masahiro Yamada
594ade3eef modpost: remove stale comment about sym_add_exported()
The description,

  it may have already been added without a
  CRC, in this case just update the CRC

... is no longer valid.

In the old days, this function was used to update the CRC as well.

Commit 040fcc819a2e ("kbuild: improved modversioning support for
external modules") started to use a separate function (sym_update_crc)
for updating the CRC.

The first part, "Add an exported symbol" is correct, but it is too
obvious from the function name. Drop this comment entirely.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:59 +09:00
Masahiro Yamada
c155a47d83 modpost: do not write out any file when error occurred
If an error occurs, modpost will fail anyway. Do not write out
any content (, which might be invalid).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08 03:16:59 +09:00