Commit Graph

4 Commits

Author SHA1 Message Date
Neale Ferguson
5d7f2fdf16 Fix loading of ET_DYN type of shared objects
* build-globals.sh
  - Only look in the nuttx for external symbols used when loading
    dynamic shared objects

* include/elf64.h
  - Correct the type of fields in the Elf64_Phdr structure

* libs/libc/dlfcn/lib_dlclose.c
  - Distinguish between ET_DYN and other objects as the former
    has both text and data in a single allocation to reserve
    GOT offsets

* libs/libc/dlfcn/lib_dlopen.c
  - Code formatting

* libs/libc/modlib/modlib_bind.c
  - Distinguish between relocation entry sizes by section type
  - Handle RELA style relocations

* libs/libc/modlib/modlib_globals.S
  - Formatting fixes
  - Symbols should not be weak - they exist or they don't

* include/nuttx/lib/modlib.h
  - Add an inidcator to module_s to distinguish between ET_DYN and other

* libs/libc/modlib/modlib_load.c
  - ET_DYN objects need to keep the relative displacement between the text
    and data sections due to GOT references from the former to the latter.
    This also implies that linking may require modification from the default
    for the shared objects being produced. For example, default alignment may
    mean nearly 64K of wasted space.

* libs/libc/modlib/modlib_unload.c
  sched/module/mod_rmmod.c
  - Distingusih between freeing of ET_DYN storage and other as the former
    is a single allocation.

* libs/libc/modlib/mod_insmod.c
  - Cater for ET_DYN objects having init and preinit sections
2023-09-20 09:35:28 -04:00
Xiang Xiao
9dc59e9109 Fix error: Mixed case identifier found
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2023-07-10 23:03:17 +03:00
Neale Ferguson
b5cd7c2a82 libs/libc/modlib: fix dynamic loader issues
* build-globals.sh
    - Macros for defining symbols etc. based on assembler in use
    - Use the System.map to get all the nuttx symbols

  * libs/libc/modlib/modlib_globals.S
    - Provide an empty skeleton. If the dynamic loading functions
      are required then run build-global.sh after a clean build
      using the skeleton. This will fill out the skeleton with the
      symbols to be available to dynamically loaded modules.

  * libs/libc/modlib/modlib_loadhdrs.c
    - Fix case where there are no program headers are avaiable
2023-07-07 13:43:20 -04:00
Neale Ferguson
fec789047a Add support for the loading of ET_DYN objects
* libs/libc/machine/arm/armv7-m/arch_elf.c
      - Fix cast of error message parameters

    * build-globals.sh
      - Build the modlib_globals.S file used to resolve symbols when dynamically loading

    * libs/libc/modlib/Make.defs
      - Build modlib_globals.S for all targets

    * libs/libc/modlib/modlib_load.c
      - Calculate sizes and text/data addresses based on program headers rather than section headers
      - Handle objects with no program headers

    * libs/libc/modlib/modlib_bind.c
      - Call modlib_readsym with pointer to symbol table
      - Add modlib_relocatedyn to manage relocation of symbols with shared object (ET_DYN)
      - Differentiate between ET_REL and ET_DYN objects
      - Use arch independent symbol ELF_R_SYM
      - Cast sizes to avoid warnings

    * libs/libc/modlib/modlib_load.c
      - Cast sizes to avoid warnings

    * include/elf.h
      - Add definitions that may be found in shared objects

    * include/nuttx/lib/modlib.h
      - Add parameter to modlib_readsym prototype
      - Add prototypes for:
        - modlib_insertsymtab
        - modlib_findglobal
      - Define Elf_Dyn and Elf_Off according to the elf architecture
      - Add fields to mod_loadifno_s:
        - Program headers
        - Exported symbols
        - Data section address
        - Padding requirement
        - Section index for dynamic symbol table
        - Number of symbols exported
      - Add prottotype for modlib_freesymtab

    * libs/libc/dlfcn/lib_dlclose.c
      - Free the symbol table when the dll is closed

    * libs/libc/dlfcn/lib_dlopen.c
      - Add dump of program headers to debug routine
      - Differentiate between ET_REL and ET_DYN objects

    * libs/libc/machine/arm/armv7-m/arch_elf.c
      - Add handling of R_ARM_RELATIVE and R_ARM_JUMP slot relocation types

    * libs/libc/modlib/modlib_loadshdrs.c
      - Rename modlib_loadshdrs.c to modlib_loadhdrs.c
      - Rename modlib_loadshdrs to modlib_loadhdrs
      - Add code to load program headers

    * libs/libc/modlib/modlib_symbols.c
      - Define entry point structure
      - Add offset parameter to modlib_symname() and use to find symbol names
      - Add symtab section header parameter to modlib_readsym()
      - Add offset parameter to modlib_symvalue() to locate symbol names
      - Add modlib_insertsyntab() to create a symbol table for exporting and resolution
      - Add findEP() to resolve a symbol in the modlib_global table
      - Add modlib_findglobal() to find symbol in the modlib_global table
      - Add modlib_freesymtab() to free the symbol table

    * libs/libc/modlib/modlib_uninit.c
      - Free header and sections from a module_loadinfo_s control block

    * libs/libc/modlib/modlib_verify.c
      - Handle ET_DYN shared objects

    * libs/libc/modlib/modlib_globals.S
      - Multi-target global table
      - Define library APIs that may be resolved when loading a shared object
2023-07-06 09:13:38 -03:00