It doesn't make any sense to parse ABI entries under
/sys/firmware, as those are either specified by ACPI specs
or by Documentation/devicetree.
The current logic to ignore firmware entries is incomplete,
as it ignores just the relative name of the file, and not
its absolute name. This cause errors while parsing the
symlinks.
So, rewrite the logic for it to do a better job.
Tested with both x86 and arm64 (HiKey970) systems.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/1c806eaec96f6706db4b041bbe6a0e2519e9637e.1632750315.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As warned, /sys/bus/iio/devices/iio:deviceX/fault_ovuv is defined 2 times:
Warning: /sys/bus/iio/devices/iio:deviceX/fault_ovuv is defined 2 times: ./Documentation/ABI/testing/sysfs-bus-iio-temperature-max31856:14 ./Documentation/ABI/testing/sysfs-bus-iio-temperature-max31865:0
The logic with joins the two entries is just places the paragraph
for the second entry after the previous one. That could cause more
warnings, as the produced ReST may become invalid, as in the case of
this specific symbol, which ends with a table:
/new_devel/v4l/docs/Documentation/ABI/testing/sysfs-bus-iio-temperature-max31856:2: WARNING: Malformed table.
No bottom table border found or no blank line after table bottom.
=== =======================================================
'1' The input voltage is negative or greater than VDD.
'0' The input voltage is positive and less than VDD (normal
state).
=== =======================================================
/new_devel/v4l/docs/Documentation/ABI/testing/sysfs-bus-iio-temperature-max31856:2: WARNING: Blank line required after table.
Address it by adding two blank lines before joining duplicated
symbols.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/4ad2e3a65f781f0f8d40bb75aa5a07aca80564d6.1632740376.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We will be enabling THREAD_INFO_IN_TASK support for ARM, which means
that we can no longer load the stack canary value by masking the stack
pointer and taking the copy that lives in thread_info. Instead, we will
be able to load it from the task_struct directly, by using the TPIDRURO
register which will hold the current task pointer when
THREAD_INFO_IN_TASK is in effect. This is much more straight-forward,
and allows us to declutter this code a bit while at it.
Note that this means that ARMv6 (non-v6K) SMP systems can no longer use
this feature, but those are quite rare to begin with, so this is a
reasonable trade off.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Kernel code has a regular need to describe groups of members within a
structure usually when they need to be copied or initialized separately
from the rest of the surrounding structure. The generally accepted design
pattern in C is to use a named sub-struct:
struct foo {
int one;
struct {
int two;
int three, four;
} thing;
int five;
};
This would allow for traditional references and sizing:
memcpy(&dst.thing, &src.thing, sizeof(dst.thing));
However, doing this would mean that referencing struct members enclosed
by such named structs would always require including the sub-struct name
in identifiers:
do_something(dst.thing.three);
This has tended to be quite inflexible, especially when such groupings
need to be added to established code which causes huge naming churn.
Three workarounds exist in the kernel for this problem, and each have
other negative properties.
To avoid the naming churn, there is a design pattern of adding macro
aliases for the named struct:
#define f_three thing.three
This ends up polluting the global namespace, and makes it difficult to
search for identifiers.
Another common work-around in kernel code avoids the pollution by avoiding
the named struct entirely, instead identifying the group's boundaries using
either a pair of empty anonymous structs of a pair of zero-element arrays:
struct foo {
int one;
struct { } start;
int two;
int three, four;
struct { } finish;
int five;
};
struct foo {
int one;
int start[0];
int two;
int three, four;
int finish[0];
int five;
};
This allows code to avoid needing to use a sub-struct named for member
references within the surrounding structure, but loses the benefits of
being able to actually use such a struct, making it rather fragile. Using
these requires open-coded calculation of sizes and offsets. The efforts
made to avoid common mistakes include lots of comments, or adding various
BUILD_BUG_ON()s. Such code is left with no way for the compiler to reason
about the boundaries (e.g. the "start" object looks like it's 0 bytes
in length), making bounds checking depend on open-coded calculations:
if (length > offsetof(struct foo, finish) -
offsetof(struct foo, start))
return -EINVAL;
memcpy(&dst.start, &src.start, offsetof(struct foo, finish) -
offsetof(struct foo, start));
However, the vast majority of places in the kernel that operate on
groups of members do so without any identification of the grouping,
relying either on comments or implicit knowledge of the struct contents,
which is even harder for the compiler to reason about, and results in
even more fragile manual sizing, usually depending on member locations
outside of the region (e.g. to copy "two" and "three", use the start of
"four" to find the size):
BUILD_BUG_ON((offsetof(struct foo, four) <
offsetof(struct foo, two)) ||
(offsetof(struct foo, four) <
offsetof(struct foo, three));
if (length > offsetof(struct foo, four) -
offsetof(struct foo, two))
return -EINVAL;
memcpy(&dst.two, &src.two, length);
In order to have a regular programmatic way to describe a struct
region that can be used for references and sizing, can be examined for
bounds checking, avoids forcing the use of intermediate identifiers,
and avoids polluting the global namespace, introduce the struct_group()
macro. This macro wraps the member declarations to create an anonymous
union of an anonymous struct (no intermediate name) and a named struct
(for references and sizing):
struct foo {
int one;
struct_group(thing,
int two;
int three, four;
);
int five;
};
if (length > sizeof(src.thing))
return -EINVAL;
memcpy(&dst.thing, &src.thing, length);
do_something(dst.three);
There are some rare cases where the resulting struct_group() needs
attributes added, so struct_group_attr() is also introduced to allow
for specifying struct attributes (e.g. __align(x) or __packed).
Additionally, there are places where such declarations would like to
have the struct be tagged, so struct_group_tagged() is added.
Given there is a need for a handful of UAPI uses too, the underlying
__struct_group() macro has been defined in UAPI so it can be used there
too.
To avoid confusing scripts/kernel-doc, hide the macro from its struct
parsing.
Co-developed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/lkml/20210728023217.GC35706@embeddedor
Enhanced-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/lkml/41183a98-bdb9-4ad6-7eab-5a7292a6df84@rasmusvillemoes.dk
Enhanced-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/lkml/1d9a2e6df2a9a35b2cdd50a9a68cac5991e7e5f0.camel@intel.com
Enhanced-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lore.kernel.org/lkml/YQKa76A6XuFqgM03@phenom.ffwll.local
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
When one searches for a main menu item, links aren't created for it like
with the rest of the symbols.
This happens because we trace the item until we get to the rootmenu, but
we don't include it in the path of the item. The rationale was probably
that we don't want to show the main menu in the path of all items,
because it is redundant.
However, when an item has only the rootmenu in its path it should be
included, because this way the user can jump to its location.
Add a 'Main menu' entry in the 'Location:' section for the kconfig
items.
This makes the 'if (i > 0)' superfluous because each item with prompt
will have at least one menu in its path.
Signed-off-by: Ariel Marcovitch <arielmarcovitch@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently, the asan-stack parameter is only passed along if
CFLAGS_KASAN_SHADOW is not empty, which requires KASAN_SHADOW_OFFSET to
be defined in Kconfig so that the value can be checked. In RISC-V's
case, KASAN_SHADOW_OFFSET is not defined in Kconfig, which means that
asan-stack does not get disabled with clang even when CONFIG_KASAN_STACK
is disabled, resulting in large stack warnings with allmodconfig:
drivers/video/fbdev/omap2/omapfb/displays/panel-lgphilips-lb035q02.c:117:12: error: stack frame size (14400) exceeds limit (2048) in function 'lb035q02_connect' [-Werror,-Wframe-larger-than]
static int lb035q02_connect(struct omap_dss_device *dssdev)
^
1 error generated.
Ensure that the value of CONFIG_KASAN_STACK is always passed along to
the compiler so that these warnings do not happen when
CONFIG_KASAN_STACK is disabled.
Link: https://github.com/ClangBuiltLinux/linux/issues/1453
References: 6baec880d7 ("kasan: turn off asan-stack for clang-8 and earlier")
Link: https://lkml.kernel.org/r/20210922205525.570068-1-nathan@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The way the search algorithm works is that reduces the number of regex
expressions that will be checked for a given file entry at sysfs. It
does that by looking at the devnode name. For instance, when it checks for
this file:
/sys/bus/pci/drivers/iosf_mbi_pci/bind
The logic will seek only the "What:" expressions that end with "bind".
Currently, there are just a couple of What expressions that matches
it:
What: /sys/bus/fsl\-mc/drivers/.*/bind
What: /sys/bus/pci/drivers/.*/bind
It will then run an O(n²) algorithm to seek, which runs quickly
when there are few regexs to seek. There are, however, some What:
expressions that end with a wildcard. Those are harder to process.
Right now, they're all grouped together at the "others" group.
As those don't depend on the basename of the node, add an extra
loop to ensure that those will be processed at the end, if
not done yet.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9fe7ab46f67575def5db9e83034e9fab43846d84.1632411447.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For CONFIG_LTO_CLANG=y, the objtool processing is not possible at the
compilation, hence postponed by the link time.
Reuse $(cmd_objtool) for CONFIG_LTO_CLANG=y by defining objtool-enabled
properly.
For CONFIG_LTO_CLANG=y:
objtool-enabled is off for %.o compilation
objtool-enabled is on for %.lto link
For CONFIG_LTO_CLANG=n:
objtool-enabled is on for %.o compilation
(but, it depends on OBJECT_FILE_NON_STANDARD)
Set part-of-module := y for %.lto.o to avoid repeating --module.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Redo commit 8852c55240 ("kbuild: Fix objtool dependency for
'OBJECT_FILES_NON_STANDARD_<obj> := n'") to add the objtool
dependency in a cleaner way.
Using .SECONDEXPANSION ends up with unreadable code due to escaped
dollars. Also, it is not efficient because the second half of
Makefile.build is parsed twice every time.
Append the objtool dependency to the *.cmd files at the build time.
This is what fixdep and gen_ksymdeps.sh already do. So, following the
same pattern seems a natural solution.
This allows us to drop $$(objtool_dep) entirely.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
objtool_dep includes include/config/{ORC_UNWINDER,STACK_VALIDATION}
so that all the objects are rebuilt when CONFIG_ORC_UNWINDER or
CONFIG_STACK_VALIDATION is toggled.
BTW, the correct option name is not CONFIG_ORC_UNWINDER, but
CONFIG_UNWINDER_ORC. Commit 11af847446 ("x86/unwind: Rename
unwinder config options to 'CONFIG_UNWINDER_*'") missed to
adjust this part. So, this dependency has been broken for a
long time.
As you can see in 'objtool_args', there are more CONFIG options
that affect the objtool command line.
Adding more and more include/config/* is ugly and unmaintainable.
Another issue is that non-standard objects are needlessly rebuilt.
Objects specified as OBJECT_FILES_NON_STANDARD is not processed by
objtool, but they are rebuilt anyway when CONFIG_STACK_VALIDATION
is toggled. This is not a big deal, but better to fix.
A cleaner and more precise fix is to include the objtool command in
*.cmd files so any command change is naturally detected by if_change.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Rename __objtool_obj to objtool, and move it out of the
'ifndef CONFIG_LTO_CLANG' conditional, so it can be used for
cmd_cc_lto_link_modules as well.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Commit b1a1a1a09b ("kbuild: lto: postpone objtool") moved objtool_args
to Makefile.lib, so the arguments can be used in Makefile.modfinal as
well as Makefile.build.
With commit 850ded46c6 ("kbuild: Fix TRIM_UNUSED_KSYMS with
LTO_CLANG"), module LTO linking came back to scripts/Makefile.build
again.
So, there is no more reason to keep objtool_args in a separate file.
Get it back to the original place, close to the objtool command.
Remove the stale comment too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
