When building relocatable extensions, exported symbol names might end
up in a separate section (in my case ".rodata.str1.1") for which
storage address don't match section address. To access those names
addresses have to be relalculated.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
The new CONFIG_LLEXT_IMPORT_ALL_GLOBALS option allows all global symbols
from extensions to be used by the main application. This is useful to
load basic extensions that have been compiled without the full Zephyr
EDK.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
Make sure the buffer used to load the hex file is aligned to a sensible
value; at least word size is assumed by the LLEXT APIs.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
The shell command 'llext list_symbols' currently iterates over the
'sym_tab' table. This is valid only inside 'llext_load' and is freed
before returning, so it will always be empty in shell context.
Fix it to display 'exp_tab', which is the one used at runtime by LLEXT
to provide symbols to the main application.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
The ELF format allows for multiple string and symbol tables with
complex references between them. This is especially evident when
debugging information is included.
This patch fixes the issues that have been identified with multiple
string tables to allow LLEXT to properly parse those files:
* The symbol table used by LLEXT (LLEXT_MEM_SYMTAB) is now chosen
depending on the loaded file type, and other tables are ignored.
This change is also applied to the SLID injection script.
* The LLEXT string table (LLEXT_MEM_SYMTAB) is now correctly identified
by the symbol table reference, instead of picking the first one.
* VMA range checks only make sense for allocated sections.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
This patch adds a debug log message to display the addresses of the
sections in a format that can be used with the gdb 'add-symbol-file'
command to properly inform the debugger about the final addresses for
the loaded sections.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
When building an ELF file with debugging information, the compiler
places this data in sections that do not need to be loaded in memory for
the program to run. These sections are marked as "not allocated" in the
ELF section header, and can be safely ignored when loading the file.
This patch adds a check to the relocation processing code to skip
relocations acting on those non-allocated sections, allowing to load ELF
files with debugging information.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
This new option allows to export devices using identifiers generated
from the hash of the devicetree node path, instead of the device's
ordinal number. Identifiers generated this way are stable across
rebuilds.
Add new test cases to test this new option.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
Ensure all pending log messages are processed by the log processing
thread when log_flush is called, blocking the caller until done.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
The check combination of "is zero" and then "less than zero" leaves open
the theoretical possibility of a positive return value, which would
continue on with an uinitialized 'sym'.
Checking for "not zero" has the same effect and covers all situations.
Commit 56fd85442 did the same thing for 'rela' a few lines above, but
missed this instance. No other places in the llext code have this issue.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
Currently llext_link_plt() calculates offsets to relocation addresses
relative to the .text section and passes them to
arch_elf_relocate_global() and arch_elf_relocate_local(), where then
.text memory address is added to them. Instead it's more logical to
concentrate the entire calculation in the caller, which then also
removes the assumption, that all sections have the same VMA - LMA
offset from those functions.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Some ARC processor configurations have separate memory for code (ICCM)
and for data (DCCM). Such configurations are unsuitable for LLEXT,
except for some quite special cases. For now, disable LLEXT and its
tests for these devices completely.
Signed-off-by: Ilya Tagunov <Ilya.Tagunov@synopsys.com>
The weak syscall symbols generated by gen_syscalls.py are currently
compiled in the LLEXT subsystem library, which is then linked among all
other Zephyr libraries in an unspecified order. This can cause the weak
symbols to override the actual syscall implementations, leading to
undefined behaviour.
To fix this, the currently generated file is split in two elements:
- syscall_exports_llext.c contains the EXPORT_SYMBOL directives for all
syscalls. This part can be compiled with the LLEXT library and linked
among all other Zephyr libraries, and ensures all syscalls symbols
are preserved by the linker.
- syscall_weakdefs_llext.c contains the weak definitions for all syscalls.
This file is compiled in a separate library that is linked last, so
that the weak symbols are only used if no other implementation is
available.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
The check combination of "is zero" and then "less than zero" leaves open
the theoretical possibility of a positive return value, which would
continue on with an uinitialized 'rela'.
Checking for "not zero" has the same effect and covers all situations.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
When linking and relocations are performed on the ELF object itself
with no copying, also global binding linking can break references.
Disable linking globally for such cases.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Now that section header cache is persistent, it can be used for
finding sections. Add a new function, similar to llext_find_section()
to use it and deprecate llext_find_section().
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Move cached section headers to struct llext from struct llext_loader
to preserve them after llext_load() returns.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Currently when building LLEXT for Xtensa we use the -fPIC compiler
option, but this cannot be used when using detached sections in
extensions. Add a Kconfig option to switch between the two
compilation modes and switch -fPIC off when building relocatable
(partially linked) ELF binaries.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
When detached sections are used, STB_GLOBAL relocations also have to
be processed depending on the relocation type. This commit unified
STB_GLOBAL and STB_LOCAL flows by making them use the same relocation
type parser, adds support for R_XTENSA_GLOB_DAT and R_XTENSA_JMP_SLOT
type relocations on Xtensa and fixes STT_SECTION address calculation
for such sections.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Detached sections are used in situ without being copied to or
referenced from ext->mem[] LLEXT region arrays. Their caches must be
synchronised accordingly.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
When CONFIG_LLEXT_STORAGE_WRITABLE is selected and .pre_located is
set, the BSS section is allocated by the user too, no need to
allocate it internally.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
This commit introduces architecture-specific ELF relocations for RISC-V,
in accordance with the RISC-V PSABI specification:
https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc
Also, the necessary compiler configurations for compiling LLEXT
extensions on RISC-V are added, and the llext tests are executed on
RISC-V targets.
Calling llext extensions from user threads in RISC-V is still
unsupported as of this commit.
Signed-off-by: Eric Ackermann <eric.ackermann@cispa.de>
Some LLEXT objects can include sections, that should not be merged
with other sections of the same type. E.g. when such sections should
be placed into locations, other than the default. Add support for
such sections.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
To simplify LLEXT loader parameter extension pass the whole
struct llext_load_param to final consumers instead of extracting
individual fields from it in the caller function.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
It's more common in the LLEXT code base to call elf_sym_t instances
"sym" and not "sym_tbl." Convert llext_link_plt() to follow this
convention.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Make llext_loaded_sect_ptr() a proper function to be able to call it
from platform LLEXT code.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
This change adds a new configuration option, LLEXT_EXPORT_DEVICES, which
enables exporting all devices defined in the device tree to llext
extensions. When enabled, all devices are made available to extensions
via the standard DT_ / DEVICE_* macros.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
There's no reason for the .exported_sym data to always land at one end of a
data region; the order of sections depends on the whim of the compiler and
assembler.
Ignore overlaps between that region and other data regions.
Signed-off-by: Keith Packard <keithp@keithp.com>
Adds support for all relocation type produced by GCC
on AARCH64 platform using partial linking (-r flag) or
shared link (-fpic and -shared flag).
Signed-off-by: Adam Wojasinski <awojasinski@baylibre.com>
Replace use of 32-bit architecture macro to macro arch agnostic that
is resolved in compilation.
Signed-off-by: Adam Wojasinski <awojasinski@baylibre.com>
Some function pointers were being passed via `%p` to LOG_DBG, and this
was causing the following issues in SOF CI with the `sparse` checker:
subsys/llext/llext.c: error: arithmetics on pointers to functions
subsys/llext/llext.c: error: incompatible types for operation (+)
This patch fixes the issue by casting the function pointers to void*.
Also fix a misleading error message in `llext_get_fn_table()`.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
Add missing braces to comply with MISRA C:2012 Rule 15.6 and
also following Zephyr's style guideline.
Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>
llext_bringup() and llext_teardown() are intended to be used to call the
extension's own initialization and cleanup functions, respectively. They
are meant to be called by the developer after loading an extension and
before unloading it. The list of function pointers to be called is
obtained via the new llext_get_fn_table() syscall, so that they are
compatible with user mode.
llext_bootstrap() is intended to be used as the entry point for a thread
created to run an extension, in either user or kernel contexts. It will
call the extension's own initialization functions and then an additional
entry point in the same context (if desired). The same function can also
be called directly in the main thread, if only initialization is
required.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
Load the .preinit_array, .init_array and .fini_array sections in ELF
files. These sections are arrays of function pointers that are filled by
the compiler with the addresses of functions that need to be called at
startup or termination by the loader, such as C++ constructors and
destructors.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
This patch extends LLEXT shell commands with support for loading
LLEXT from a filesystem. Use of the command requires absolute path
to the llext file.
Example use:
`llext load_llext hello_world /lfs/hello_world.llext`
Signed-off-by: Adam Wojasinski <awojasinski@baylibre.com>
Introducing `llext_prepare()` and `llext_finalize()` APIs
that are invoked and the beginning and the end of the `llext_load()`
function.
The purpose of these functions is to bring possibility of initializing
loader before it is used and uninitialize or clean up when
it is no longer needed. Both functions are optional.
The buffer loader has been aligned to methods introduced in the patch.
Signed-off-by: Adam Wojasinski <awojasinski@baylibre.com>
By default, normal memory is set readable+writable and not executable.
Adjust those permissions according to each region:
LLEXT_MEM_TEXT --> K_MEM_PERM_EXEC
LLEXT_MEM_DATA, LLEXT_MEM_BSS --> K_MEM_PERM_RW
LLEXT_MEM_RODATA --> K_MEM_PERM_RO aka 0
This must be done only at the end of an LLEXT load operation as memory
needs to remain RW for reloc processing, etc.
And while at it, flush/invalidate the cache accordingly.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
When an LLEXT object uses symbols of another such object, it depends
on it. Such dependencies have to be tracked to prevent their
accidental unloading. Ideally we should be able to track arbitrary
numbers of such dependencies, but this is a bit difficult. In this
first implementation we use a fixed-size array, currently consisting
of 8 entries.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
When deciding which sections to group together, only the low 3
section attribute bits are relevant, ignore the rest.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
LLEXT objects can also export symbols for use by other such objects.
That means, that when linking an LLEXT object we have to look for
unresolved symbols in previously loaded objects too.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Extensions could have used logging, when log processing is
deferred, the logging thread can run after the extension has
been unloaded and thereby access invalid memory addresses.
Make sure to flush all logs before unloading extensions.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Add missing braces to comply with MISRA C:2012 Rule 15.6 and
also following Zephyr's style guideline.
Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>
Review and improve comments in source code to better describe the API
and the functionality provided by the llext library.
No actual code changes are performed in this commit.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
The term "section" has a very specific meaning in the ELF file format.
After 709b2e4 ("llext: automatically merge sections by type"), some of
the code that was originally dealing with ELF sections is now handling
"memory regions" made of multiple ELF sections of the same type.
Make sure to use the term "region" consistently in the code and
log messages to avoid confusion with the original ELF sections.
Notable exception to this is the "ldr->sect" array, which is actively
used outside Zephyr and will need to be phased out in the future.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
This patch changes the error codes returned by the ELF subsystem to be
more consistent with the standard error descriptions. In particular:
- issues with the ELF file are now reported as -ENOEXEC;
- valid but unsupported edge cases are reported as -ENOTSUP;
- failures in searching for an entry are reported as -ENOENT.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
