6602 Commits

Author SHA1 Message Date
Rasmus Villemoes
5cc1247204 kbuild: add CONFIG_VMLINUX_MAP expert option
It can be quite useful to have ld emit a link map file, in order to
debug or verify that special sections end up where they are supposed
to, and to see what LD_DEAD_CODE_DATA_ELIMINATION manages to get rid
of.

The only reason I'm not just adding this unconditionally is that the
.map file can be rather large (several MB), and that's a waste of
space when one isn't interested in these things. Also make it depend
on CONFIG_EXPERT.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:12:26 +09:00
Masahiro Yamada
57fd251c78 kbuild: split cc-option and friends to scripts/Makefile.compiler
scripts/Kbuild.include is included everywhere, but macros such as
cc-option are needed by build targets only.

For example, when 'make clean' traverses the tree, it does not need
to evaluate $(call cc-option,).

Split cc-option, ld-option, etc. to scripts/Makefile.compiler, which
is only included from the top Makefile and scripts/Makefile.build.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:09:32 +09:00
Randy Dunlap
92f8a9217a kconfig: highlight xconfig 'comment' lines with '***'
Mark Kconfig "comment" lines with "*** <commentstring> ***"
so that it is clear that these lines are comments and not some
kconfig item that cannot be modified.

This is helpful in some menus to be able to provide a menu
"sub-heading" for groups of similar config items.

This also makes the comments be presented in a way that is
similar to menuconfig and nconfig.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-19 14:58:23 +09:00
Randy Dunlap
5fb35ec10b kconfig: highlight gconfig 'comment' lines with '***'
Mark Kconfig "comment" lines with "*** <commentstring> ***"
so that it is clear that these lines are comments and not some
kconfig item that cannot be modified.

This is helpful in some menus to be able to provide a menu
"sub-heading" for groups of similar config items.

This also makes the comments be presented in a way that is
similar to menuconfig and nconfig.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-19 14:57:16 +09:00
Masahiro Yamada
ed63ef7796 kconfig: gconf: remove unused code
Remove the unused <config.h> inclusion, and commented out lines.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-19 14:50:35 +09:00
Masahiro Yamada
989e5d4b57 kconfig: remove unused PACKAGE definition
Commit 3b9fa0931dd8 ("[PATCH] Kconfig i18n support") added this code,
and then commit ("kconfig: drop localization support") removed the
i18n support entirely.

Remove the left-over.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-19 14:50:16 +09:00
Jakub Kicinski
8203c7ce4e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
 - keep the ZC code, drop the code related to reinit
net/bridge/netfilter/ebtables.c
 - fix build after move to net_generic

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-04-17 11:08:07 -07:00
Walter Wu
02c587733c kasan: remove redundant config option
CONFIG_KASAN_STACK and CONFIG_KASAN_STACK_ENABLE both enable KASAN stack
instrumentation, but we should only need one config, so that we remove
CONFIG_KASAN_STACK_ENABLE and make CONFIG_KASAN_STACK workable.  see [1].

When enable KASAN stack instrumentation, then for gcc we could do no
prompt and default value y, and for clang prompt and default value n.

This patch fixes the following compilation warning:

  include/linux/kasan.h:333:30: warning: 'CONFIG_KASAN_STACK' is not defined, evaluates to 0 [-Wundef]

[akpm@linux-foundation.org: fix merge snafu]

Link: https://bugzilla.kernel.org/show_bug.cgi?id=210221 [1]
Link: https://lkml.kernel.org/r/20210226012531.29231-1-walter-zh.wu@mediatek.com
Fixes: d9b571c885a8 ("kasan: fix KASAN_STACK dependency for HW_TAGS")
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-16 16:10:36 -07:00
Arnd Bergmann
5c595ac4c7 kasan: fix hwasan build for gcc
gcc-11 adds support for -fsanitize=kernel-hwaddress, so it becomes
possible to enable CONFIG_KASAN_SW_TAGS.

Unfortunately this fails to build at the moment, because the
corresponding command line arguments use llvm specific syntax.

Change it to use the cc-param macro instead, which works on both clang
and gcc.

[elver@google.com: fixup for "kasan: fix hwasan build for gcc"]
  Link: https://lkml.kernel.org/r/YHQZVfVVLE/LDK2v@elver.google.com

Link: https://lkml.kernel.org/r/20210323124112.1229772-1-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-16 16:10:36 -07:00
Mihai Moldovan
8c94b430b9 kconfig: nconf: stop endless search loops
If the user selects the very first entry in a page and performs a
search-up operation, or selects the very last entry in a page and
performs a search-down operation that will not succeed (e.g., via
[/]asdfzzz[Up Arrow]), nconf will never terminate searching the page.

The reason is that in this case, the starting point will be set to -1
or n, which is then translated into (n - 1) (i.e., the last entry of
the page) or 0 (i.e., the first entry of the page) and finally the
search begins. This continues to work fine until the index reaches 0 or
(n - 1), at which point it will be decremented to -1 or incremented to
n, but not checked against the starting point right away. Instead, it's
wrapped around to the bottom or top again, after which the starting
point check occurs... and naturally fails.

My original implementation added another check for -1 before wrapping
the running index variable around, but Masahiro Yamada pointed out that
the actual issue is that the comparison point (starting point) exceeds
bounds (i.e., the [0,n-1] interval) in the first place and that,
instead, the starting point should be fixed.

This has the welcome side-effect of also fixing the case where the
starting point was n while searching down, which also lead to an
infinite loop.

OTOH, this code is now essentially all his work.

Amazingly, nobody seems to have been hit by this for 11 years - or at
the very least nobody bothered to debug and fix this.

Signed-off-by: Mihai Moldovan <ionic@ionic.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-16 14:39:12 +09:00
Jonathan Corbet
e9dfeed251 docs: sphinx-pre-install: don't barf on beta Sphinx releases
sphinx-pre-install is picky when it comes to parsing sphinx versions; it
failed when run with sphinx 4.0.0b1.  Tweak the regex to tolerate a
trailing "bN" on the version number.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-15 16:01:50 -06:00
Aditya Srivastava
f9bbc12ccb scripts: kernel-doc: improve parsing for kernel-doc comments syntax
Currently kernel-doc does not identify some cases of probable kernel
doc comments, for e.g. pointer used as declaration type for identifier,
space separated identifier, etc.

Some example of these cases in files can be:
i)" *  journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure"
in fs/jbd2/journal.c

ii) "*      dget, dget_dlock -      get a reference to a dentry" in
include/linux/dcache.h

iii) "  * DEFINE_SEQLOCK(sl) - Define a statically allocated seqlock_t"
in include/linux/seqlock.h

Also improve identification for non-kerneldoc comments. For e.g.,

i) " *	The following functions allow us to read data using a swap map"
in kernel/power/swap.c does follow the kernel-doc like syntax, but the
content inside does not adheres to the expected format.

Improve parsing by adding support for these probable attempts to write
kernel-doc comment.

Suggested-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/lkml/87mtujktl2.fsf@meer.lwn.net
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210414192529.9080-1-yashsri421@gmail.com
[ jc: fixed some line-length issues ]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-15 15:26:06 -06:00
Masahiro Yamada
a77a05dc9c kconfig: split menu.c out of parser.y
Compile menu.c as an independent compilation unit.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:26:09 +09:00
Masahiro Yamada
08718745d8 kconfig: nconf: refactor in print_in_middle()
This helper is the same as the sample code in the NCURSES HOWTO [1],
but it is over-engineering to be used for nconf.

I do not see any good reason to use the 'float' type just for the
division by 2.

All the call-sites pass a non-NULL pointer to the first argument,
so 'if (win == NULL) win = stdscr;' is dead code.

'if (startx != 0) x = startx;' is dead code because 'x' will be
overridden some lines below, by 'x = startx + (int)temp;'.

All the call-sites pass a non-zero value to the second argument,
so 'if (starty != 0)' is always true.

getyx(win, y, x) is also dead-code because both 'y' and 'x' are
overridden.

All the call-sites pass 0 to the third parameter, so 'startx' can
be removed.

All the call-sites pass a non-zero value to the fourth parameter,
so 'if (width == 0) width = 80;' is dead code.

The window will be refreshed later, so there is no need to call
refresh() in this function.

Change the type of the last parameter from 'chtype' to 'int' to be
aligned with the prototype, 'int wattrset(WINDOW *win, int attrs);'

I also slightly cleaned up the indentation style.

[1]: https://tldp.org/HOWTO/NCURSES-Programming-HOWTO/color.html

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:25:43 +09:00
Masahiro Yamada
0a94768cfd kconfig: nconf: remove meaningless wattrset() call from show_menu()
This attribute is not used because it will be overridden some lines
below:

  wattrset(main_window, attr_main_menu_box);

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:25:43 +09:00
Masahiro Yamada
ecdb733f8f kconfig: nconf: change set_config_filename() to void function
No one uses the return value of this function.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:25:43 +09:00
Masahiro Yamada
93487b17b1 kconfig: nconf: refactor attributes setup code
The current attributes setup code is strange; the array attribute[]
is set to values outside the range of the attribute_t enum.

At least,

  attributes_t attributes[ATTR_MAX+1] = {0};

... should be

  int attribute[ATTR_MAX+1] = {0};

Also, there is no need to hard-code the color-pair numbers in
attributes_t.

The current code is messy. Rewrite it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:25:13 +09:00
Masahiro Yamada
16b0e10238 kconfig: nconf: remove unneeded default for menu prompt
The rootmenu always has a prompt even if the 'mainmenu' statement is
missing in the top Kconfig file.

conf_parse() calls menu_add_prompt(P_MENU, "Main menu", NULL) in this
case.

So, every 'menu' has a prompt.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Masahiro Yamada
2ba50da9ec kconfig: nconf: get rid of (void) casts from wattrset() calls
This reverts commit 10175ba65fde ("nconfig: Silence unused return values
from wattrset").

With this patch applied, recent GCC versions can cleanly build nconf
without "value computed is not used" warnings.

The wattrset() used to be implemented as a macro, like this:

  #define wattrset(win,at) \
          (NCURSES_OK_ADDR(win) \
            ? ((win)->_attrs = NCURSES_CAST(attr_t, at), \
               OK) \
            : ERR)

The GCC bugzilla [1] reported a false-positive -Wunused-value warning
in a similar test case. It was fixed by GCC 4.4.1.

Let's revert that commit, and see if somebody will claim the issue.

[1]: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=39889

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Masahiro Yamada
7f5ff55bf8 kconfig: nconf: fix NORMAL attributes
The lower 8-bit of attributes should be 0, but this code wrongly
sets it to NORMAL (=1). The correct one is A_NORMAL.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Masahiro Yamada
68876c38c4 kconfig: mconf,nconf: remove unneeded '\0' termination after snprintf()
snprintf() always terminates the destination buffer with '\0' even if
the buffer is not long enough. (In this case, the last element of the
buffer becomes '\0'.)

The explicit termination is unneeded.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Masahiro Yamada
f02aa48dde kconfig: use /boot/config-* etc. as DEFCONFIG_LIST only for native build
When the .config file is missing, 'make config', 'make menuconfig', etc.
uses a file listed in DEFCONFIG_LIST, if found, as base configuration.

Ususally, /boot/config-$(uname -r) exists, and is used as default.

However, when you are cross-compiling the kernel, it does not make
sense to use /boot/config-* on the build host. It should default to
arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG).

UML previously did not use DEFCONFIG_LIST at all, but it should be
able to use arch/um/configs/$(KBUILD_DEFCONFIG) as a base config file.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Masahiro Yamada
5ee5465940 kconfig: change sym_change_count to a boolean flag
sym_change_count has no good reason to be 'int' type.

sym_set_change_count() compares the old and new values after casting
both of them to (bool). I do not see any practical diffrence between
sym_set_change_count(1) and sym_add_change_count(1).

Use the boolean flag, conf_changed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Masahiro Yamada
1f035a5291 kconfig: nconf: fix core dump when searching in empty menu
The following code in get_mext_match():

  index = (index + items_num) % items_num;

... makes the program crash when items_num is zero (that is, the menu
is empty).

A menu can be empty when all the options in it are hidden by unmet
'depends on'.

For example,

  menu "This menu will be empty"

  config FOO
         bool "foo"
         depends on BROKEN

  endmenu

If you visit this menu and press a '/' key and then another key, nconf
crashes with:

  Floating point exception (core dumped)

When the number of items is zero, it does not make sense to search in
the menu. In this case, current_item() returns NULL, and item_index()
ERR, but get_mext_match() does not check it.

Let's make get_mext_match() just return if the menu is empty.

While I am here, change items_num from 'int' to 'unsigned int' because
it should never become negative.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Bhaskar Chowdhury
bffbf6e2ad kconfig: lxdialog: A spello fix and a punctuation added
s/propperly/properly/
s/thats/that\'s/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Bhaskar Chowdhury
21f8b32fbd kconfig: streamline_config.pl: Couple of typo fixes
s/configuraton/configuration/
s/orignal/original/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Yang Li
a69b191f62 kconfig: use true and false for bool variable
fixed the following coccicheck:
./scripts/kconfig/confdata.c:36:9-10: WARNING: return of 0/1 in function
'is_dir' with return type bool

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Masahiro Yamada
6dd85ff178 kconfig: change "modules" from sub-option to first-level attribute
Now "modules" is the only member of the "option" property.

Remove "option", and move "modules" to the top level property.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Masahiro Yamada
ab838577aa kconfig: remove allnoconfig_y option
Now that the only user, CONFIG_EMBEDDED has stopped using this option,
remove it entirely.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Masahiro Yamada
f8f0d06438 kconfig: do not use allnoconfig_y option
allnoconfig_y is an ugly hack that sets a symbol to 'y' by allnoconfig.

allnoconfig does not mean a minimal set of CONFIG options because a
bunch of prompts are hidden by 'if EMBEDDED' or 'if EXPERT', but I do
not like to hack Kconfig this way.

Use the pre-existing feature, KCONFIG_ALLCONFIG, to provide a one
liner config fragment. CONFIG_EMBEDDED=y is still forced when
allnoconfig is invoked as a part of tinyconfig.

No change in the .config file produced by 'make tinyconfig'.

The output of 'make allnoconfig' will be changed; we will get
CONFIG_EMBEDDED=n because allnoconfig literally sets all symbols to n.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Masahiro Yamada
dd4659963a kconfig: move default KBUILD_DEFCONFIG back to scripts/kconfig/Makefile
This is a partial revert of commit 2a86f6612164 ("kbuild: use
KBUILD_DEFCONFIG as the fallback for DEFCONFIG_LIST").

Now that the reference to $(DEFCONFIG_LIST) was removed from
init/Kconfig, the default KBUILD_DEFCONFIG can go back home.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:49 +09:00
Masahiro Yamada
b75b0a819a kconfig: change defconfig_list option to environment variable
"defconfig_list" is a weird option that defines a static symbol that
declares the list of base config files in case the .config does not
exist yet.

This is quite different from other normal symbols; we just abused the
"string" type and the "default" properties to list out the input files.
They must be fixed values since these are searched for and loaded in
the parse stage.

It is an ugly hack, and should not exist in the first place. Providing
this feature as an environment variable is a saner approach.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:48 +09:00
Masahiro Yamada
406616213b kconfig: move JUMP_NB to mconf.c
This macro is only used in mconf.c.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:22:48 +09:00
Masahiro Yamada
98f8475c78 kconfig: move conf_set_all_new_symbols() to conf.c
This function is only used in conf.c. Move it there together with the
randomize_choice_values() helper.

Define 'enum conf_def_mode' locally in conf.c as well.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-14 15:20:14 +09:00
Ilya Leoshkevich
db16c1fe92 bpf: Generate BTF_KIND_FLOAT when linking vmlinux
pahole v1.21 supports the --btf_gen_floats flag, which makes it
generate the information about the floating-point types [1].

Adjust link-vmlinux.sh to pass this flag to pahole in case it's
supported, which is determined using a simple version check.

[1] https://lore.kernel.org/dwarves/YHRiXNX1JUF2Az0A@kernel.org/

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413190043.21918-1-iii@linux.ibm.com
2021-04-13 14:34:27 -07:00
Daniel Vetter
213cc929cb Merge drm/drm-fixes into drm-next
msm-next pull request has a baseline with stuff from -fixes, roll
forward first.

Some simple conflicts in amdgpu, ttm and one in i915 where git gets
confused and tries to add the same function twice.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2021-04-13 23:15:09 +02:00
Jakub Kicinski
8859a44ea0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:

MAINTAINERS
 - keep Chandrasekar
drivers/net/ethernet/mellanox/mlx5/core/en_main.c
 - simple fix + trust the code re-added to param.c in -next is fine
include/linux/bpf.h
 - trivial
include/linux/ethtool.h
 - trivial, fix kdoc while at it
include/linux/skmsg.h
 - move to relevant place in tcp.c, comment re-wrapped
net/core/skmsg.c
 - add the sk = sk // sk = NULL around calls
net/tipc/crypto.c
 - trivial

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-04-09 20:48:35 -07:00
Sami Tolvanen
28aad1c290 module: ensure __cfi_check alignment
CONFIG_CFI_CLANG_SHADOW assumes the __cfi_check() function is page
aligned and at the beginning of the .text section. While Clang would
normally align the function correctly, it fails to do so for modules
with no executable code.

This change ensures the correct __cfi_check() location and
alignment. It also discards the .eh_frame section, which Clang can
generate with certain sanitizers, such as CFI.

Link: https://bugs.llvm.org/show_bug.cgi?id=46293
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-5-samitolvanen@google.com
2021-04-08 16:04:21 -07:00
Sami Tolvanen
cf68fffb66 add support for Clang CFI
This change adds support for Clang’s forward-edge Control Flow
Integrity (CFI) checking. With CONFIG_CFI_CLANG, the compiler
injects a runtime check before each indirect function call to ensure
the target is a valid function with the correct static type. This
restricts possible call targets and makes it more difficult for
an attacker to exploit bugs that allow the modification of stored
function pointers. For more details, see:

  https://clang.llvm.org/docs/ControlFlowIntegrity.html

Clang requires CONFIG_LTO_CLANG to be enabled with CFI to gain
visibility to possible call targets. Kernel modules are supported
with Clang’s cross-DSO CFI mode, which allows checking between
independently compiled components.

With CFI enabled, the compiler injects a __cfi_check() function into
the kernel and each module for validating local call targets. For
cross-module calls that cannot be validated locally, the compiler
calls the global __cfi_slowpath_diag() function, which determines
the target module and calls the correct __cfi_check() function. This
patch includes a slowpath implementation that uses __module_address()
to resolve call targets, and with CONFIG_CFI_CLANG_SHADOW enabled, a
shadow map that speeds up module look-ups by ~3x.

Clang implements indirect call checking using jump tables and
offers two methods of generating them. With canonical jump tables,
the compiler renames each address-taken function to <function>.cfi
and points the original symbol to a jump table entry, which passes
__cfi_check() validation. This isn’t compatible with stand-alone
assembly code, which the compiler doesn’t instrument, and would
result in indirect calls to assembly code to fail. Therefore, we
default to using non-canonical jump tables instead, where the compiler
generates a local jump table entry <function>.cfi_jt for each
address-taken function, and replaces all references to the function
with the address of the jump table entry.

Note that because non-canonical jump table addresses are local
to each component, they break cross-module function address
equality. Specifically, the address of a global function will be
different in each module, as it's replaced with the address of a local
jump table entry. If this address is passed to a different module,
it won’t match the address of the same function taken there. This
may break code that relies on comparing addresses passed from other
components.

CFI checking can be disabled in a function with the __nocfi attribute.
Additionally, CFI can be disabled for an entire compilation unit by
filtering out CC_FLAGS_CFI.

By default, CFI failures result in a kernel panic to stop a potential
exploit. CONFIG_CFI_PERMISSIVE enables a permissive mode, where the
kernel prints out a rate-limited warning instead, and allows execution
to continue. This option is helpful for locating type mismatches, but
should only be enabled during development.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-2-samitolvanen@google.com
2021-04-08 16:04:20 -07:00
Mauro Carvalho Chehab
56ddc4cd4c docs: dt: update writing-schema.rst references
Changeset b83db5b84900 ("docs: dt: Group DT docs into relevant sub-sections")
renamed: Documentation/devicetree/writing-schema.rst
to: Documentation/devicetree/bindings/writing-schema.rst.

Update the cross-references accordingly.

Fixes: b83db5b84900 ("docs: dt: Group DT docs into relevant sub-sections")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/7cfddf303f1508d26f90d87546d3812faebfc5ba.1617279356.git.mchehab+huawei@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
2021-04-07 13:02:07 -05:00
Greg Kroah-Hartman
422d224513 Merge 5.12-rc6 into char-misc-next
We need the char/misc fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-05 08:43:50 +02:00
Sean Christopherson
6a3193cdd5 kbuild: lto: Merge module sections if and only if CONFIG_LTO_CLANG is enabled
Merge module sections only when using Clang LTO. With ld.bfd, merging
sections does not appear to update the symbol tables for the module,
e.g. 'readelf -s' shows the value that a symbol would have had, if
sections were not merged. ld.lld does not show this problem.

The stale symbol table breaks gdb's function disassembler, and presumably
other things, e.g.

  gdb -batch -ex "file arch/x86/kvm/kvm.ko" -ex "disassemble kvm_init"

reads the wrong bytes and dumps garbage.

Fixes: dd2776222abb ("kbuild: lto: merge module sections")
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210322234438.502582-1-seanjc@google.com
2021-04-01 14:15:59 -07:00
Mauro Carvalho Chehab
2ae7bb570e scripts: get_abi: ignore code blocks for cross-references
The script should not generate cross-references inside
literal blocks.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/a590f994f8a5742db333bde69e88241a080e4fe0.1616668017.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31 13:53:16 -06:00
Mauro Carvalho Chehab
c27c2e3441 scripts: get_abi.pl: parse description line per line
Change the description parsing logic in rst mode in order
to parse it line per line.

The end result is the same, but doing line per line allows
to add some code to escape literal blocks when seeking for
cross-references.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/d33cfa2e59ecf8f28d4ed7de7402468cf2168921.1616668017.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31 13:53:16 -06:00
Mauro Carvalho Chehab
87ec9ea1fc scripts: get_abi.pl: extend xref match to other types
Currently, there are "What:" symbols for more than just
/sys.

Extend the regex to also cover configfs, /proc /dev and /kvd
symbols.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/a1c7e2b2c37ed6e111dfc8641deb37ed96375a63.1616668017.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31 13:53:16 -06:00
Mauro Carvalho Chehab
50ebf8f493 get_abi.pl: fix xref boundaries
There are some issues with the regex that seeks for What:
cross references: basically, it is mis-identifying the start
and the end boundaries of the regex, which causes :ref: to
be inseerted for the wrong symbols at the wrong places.

Fix it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/79a14d2518499b76931b5f29c50979987108152d.1616668017.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31 13:53:16 -06:00
Mauro Carvalho Chehab
d3e6b2235e get_abi.pl: seek for all occurrences for Documentation/ABI
Instead of retrieving just one match at most, ensure that the entire
description will be parsed.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/17019b73e106d1b1b353b8880ed189bad3604c13.1616668017.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31 13:53:15 -06:00
Mauro Carvalho Chehab
b0f9580a88 scripts: get_abi.pl: better handle escape chars on what:
The parser for the symbols defined on What: doesn't cover all
chars that need to be scaped, like '{' and '}'. Change the logic
to be more generic, and ensure that the same regex will be used
on both What: and when parsing the cross-references.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/29cb56def89b508fe605bcd2ba74a4376cc08e35.1616668017.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31 13:53:15 -06:00
Carlos de Paula
7d0bc44bd0
kbuild: buildtar: add riscv support
Make 'make tar-pkg' and 'tarbz2-pkg' work on riscv.

Signed-off-by: Carlos de Paula <me@carlosedp.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-29 23:13:30 -07:00
Aditya Srivastava
3e58e83915 scripts: kernel-doc: add warning for comment not following kernel-doc syntax
Currently, kernel-doc start parsing the comment as a kernel-doc comment if
it starts with '/**', but does not take into account if the content inside
the comment too, adheres with the expected format.
This results in unexpected and unclear warnings for the user.

E.g., running scripts/kernel-doc -none mm/memcontrol.c emits:
"mm/memcontrol.c:961: warning: expecting prototype for do not fallback to current(). Prototype was for get_mem_cgroup_from_current() instead"

Here kernel-doc parses the corresponding comment as a kernel-doc comment
and expects prototype for it in the next lines, and as a result causing
this warning.

Provide a clearer warning message to the users regarding the same, if the
content inside the comment does not follow the kernel-doc expected format.

Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210329092945.13152-1-yashsri421@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-29 17:08:28 -06:00