Per the GCC bug listed below, the way we do linker lists is relying on
undefined behavior that seems to work in gcc, but doesn't always work in
clang. Andrew suggests rewriting our start/end macros in a different way
(as implemented here, from what he said in comment 1) to avoid these
problems.
Reported-by: AdityaK <appujee@google.com>
Suggested-by: Andrew Pinski <apinski@marvell.com>
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108915
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andrew Pinski <apinski@marvell.com>
Rename the sections used to implement linker lists so they begin with
'__u_boot_list' rather than '.u_boot_list'. The double underscore at the
start is still distinct from the single underscore used by the symbol
names.
Having a '.' in the section names conflicts with clang's ASAN
instrumentation which tries to add redzones between the linker list
elements, causing expected accesses to fail. However, clang doesn't try
to add redzones to user sections, which are names with all alphanumeric
and underscore characters.
Signed-off-by: Andrew Scull <ascull@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commit does the same thing as Linux commit 33def8498fdd.
Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.
Remove the quote operator # from compiler_attributes.h __section macro.
Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Avoid 'make htmldocs' build warnings:
./include/linker_lists.h:224: warning:
Function parameter or member '_type' not described in 'll_entry_ref'
./include/linker_lists.h:224: warning:
Function parameter or member '_name' not described in 'll_entry_ref'
./include/linker_lists.h:224: warning:
Function parameter or member '_list' not described in 'll_entry_ref'
Fixes: 851144350b ("linker_lists: Allow use in data structures")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Add macros which work with instantiated devices and uclasses, as created
at build time by dtoc. Include variants that can be used in data
structures.
These are mostly used by dtoc but it is worth documenting them fully for
the occasional case where they might come up in user code.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
At present linker lists are designed for use in code. They make use of
statements within expressions ({...}), for example.
It is possible to generate a reference to a linker_list entry that can
be used in data structures, where such features are not permitted. It
requires that the reference first be declared as extern. In other
words the existing macro needs to be split into two parts.
Add new macros to support this.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
The linker script uses alphabetic sorting to group the different linker
lists together. Each group has its own struct and potentially its own
alignment. But when the linker packs the structs together it cannot ensure
that a linker list starts on the expected alignment boundary.
For example, if the first list has a struct size of 8 and we place 3 of
them in the image, that means that the next struct will start at offset
0x18 from the start of the linker_list section. If the next struct has
a size of 16 then it will start at an 8-byte aligned offset, but not a
16-byte aligned offset.
With sandbox on x86_64, a reference to a linker list item using
ll_entry_get() can force alignment of that particular linker_list item,
if it is in the same file as the linker_list item is declared.
Consider this example, where struct driver is 0x80 bytes:
ll_entry_declare(struct driver, fred, driver)
...
void *p = ll_entry_get(struct driver, fred, driver)
If these two lines of code are in the same file, then the entry is forced
to be aligned at the 'struct driver' alignment, which is 16 bytes. If the
second line of code is in a different file, then no action is taken, since
the compiler cannot update the alignment of the linker_list item.
In the first case, an 8-byte 'fill' region is added:
.u_boot_list_2_driver_2_testbus_drv
0x0000000000270018 0x80 test/built-in.o
0x0000000000270018 _u_boot_list_2_driver_2_testbus_drv
.u_boot_list_2_driver_2_testfdt1_drv
0x0000000000270098 0x80 test/built-in.o
0x0000000000270098 _u_boot_list_2_driver_2_testfdt1_drv
*fill* 0x0000000000270118 0x8
.u_boot_list_2_driver_2_testfdt_drv
0x0000000000270120 0x80 test/built-in.o
0x0000000000270120 _u_boot_list_2_driver_2_testfdt_drv
.u_boot_list_2_driver_2_testprobe_drv
0x00000000002701a0 0x80 test/built-in.o
0x00000000002701a0 _u_boot_list_2_driver_2_testprobe_drv
With this, the linker_list no-longer works since items after testfdt1_drv
are not at the expected address.
Ideally we would have a way to tell gcc not to align structs in this way.
It is not clear how we could do this, and in any case it would require us
to adjust every struct used by the linker_list feature.
One possible fix is to force each separate linker_list to start on the
largest possible boundary that can be required by the compiler. However
that does not seem to work on x86_64, which uses 16-byte alignment in this
case but needs 32-byte alignment.
So add a Kconfig option to handle this. Set the default value to 4 so
as to avoid changing platforms that don't need it.
Update the ll_entry_start() accordingly.
Signed-off-by: Simon Glass <sjg@chromium.org>
The Linux kernel moved to sphinx-based documentation and got rid of the
DocBook based documentation quite a while ago. Hence, the DocBook
documentation for U-Boot should be converted as well.
To achieve this, import the necessary files from Linux v4.17, and
convert the current DocBook documentation (three files altogether) to
sphinx/reStructuredText.
For now, all old DocBook documentation was merged into a single
handbook, tentatively named "U-Boot Hacker Manual".
For some source files, the documentation style was changed to comply
with kernel-doc; no functional changes were applied.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from. So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry. Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.
In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.
This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents. There's also a few places where I found we did not have a tag
and have introduced one.
Signed-off-by: Tom Rini <trini@konsulko.com>
This corrects several typos in the comment block as well as some
indentions and nits in the linker_lists.h.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Once declared, you cannot access a linker_list entry since you do not have
a symbol name for it. Add llsym() macro to provide this. This avoids
searching for the symbol at run-time based on name.
An example usage is to declare a driver with U_BOOT_DRIVER(), then obtain
a pointer to that driver later.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Marek Vasut <marex@denx.de>
The existing ll_entry_declare() permits a single element of the list to
be added to a linker list. Sometimes we want to add several objects at
once. To avoid lots of messy declarations, add a macro to support this.
Signed-off-by: Simon Glass <sjg@chromium.org>
The header file include/linker_lists.h uses __aligned();
therefore it depends on include/linux/compiler.h
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>
The section name and the C variable name seem to be opposite.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Marek Vasut <marex@denx.de>
Acked-by: Marek Vasut <marex@denx.de>
Last argument shouldn't be there.
Signed-off-by: Mateusz Zalega <m.zalega@samsung.com>
Acked-by: Marek Vasut <marex@denx.de>
Cc: Tom Rini <trini@ti.com>
- Delete fs.xml from DOCBOOKS to fix an error.
Commit e3ff797c added fs.xml to DOCBOOKS
but missed to add doc/DocBook/fs.tmpl.
- Fix the location of include guard in include/linker_lists.h.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reported-by: Abraham Varricatt <abraham.varricatt@vvdntech.com>
Acked-by: Simon Glass <sjg@chromium.org>
Refactor linker-generated array code so that symbols
which were previously linker-generated are now compiler-
generated. This causes relocation records of type
R_ARM_ABS32 to become R_ARM_RELATIVE, which makes
code which uses LGA able to run before relocation as
well as after.
Note: this affects more than ARM targets, as linker-
lists span possibly all target architectures, notably
PowerPC.
Conflicts:
arch/arm/cpu/arm926ejs/mxs/u-boot-spl.lds
arch/arm/cpu/arm926ejs/spear/u-boot-spl.lds
arch/arm/cpu/armv7/omap-common/u-boot-spl.lds
board/ait/cam_enc_4xx/u-boot-spl.lds
board/davinci/da8xxevm/u-boot-spl-da850evm.lds
board/davinci/da8xxevm/u-boot-spl-hawk.lds
board/vpac270/u-boot-spl.lds
Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
This patch adds support for linker-generated array. These arrays
are a generalization of the U-Boot command declaration approach.
Basically, the idea is to generate an array, where elements of the
array are statically initialized at compile time and each element
is declared separatelly at different place. Such array is assembled
together into continuous piece of memory by linker and a pointer to
it's first entry can then be retrieved via accessor.
The actual implementation relies on placing any variable that is to
represent an element of LG-array into particular subsection of the
.u_boot_list linker section . The subsection is determined by user
options. Once compiled, it is possible to dump all symbols placed
in .u_boot_list section and the subsections in which they should be
and generate appropriate bounds for each requested subsection of the
.u_boot_list section. Each such subsection thus contains __start and
__end entries at the begining and end respecitively.
This allows for simple run-time traversing of the array, since the
symbols are properly defined.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Joe Hershberger <joe.hershberger@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
