The following changes make it possible for Nuttx to load binaries in ELF format which are fully linked.
The change does not include the necessary modifications to produce such binaries. In order to build an applicable binary:
- The userspace applications linker script (`gnu-elf.ld`) needs to modified so the data and text section origin's match those setup by the address environment.
- The makefile used, in `apps/import/Make.defs` needs to remove the `-r` LDELFFLAG.
Instead of using a volatile storage for the address environment in the
binfmt / loadinfo structures, always allocate the address environment
from kheap.
This serves two purposes:
- If the task creation fails, any kernel thread that depends on the
address environment created during task creation will not lose their
mappings (because they hold a reference to it)
- The current address environment variable (g_addrenv) will NEVER contain
a stale / incorrect value
- Releasing the address environment is simplified as any pointer given
to addrenv_drop() can be assumed to be heap memory
- Makes the kludge function addrenv_clear_current irrelevant, as the
system will NEVER have invalid mappings any more
The function is not relevant any longer, remove it. Also remove
save_addrenv_t, the parameter taken by up_addrenv_restore.
Implement addrenv_select() / addrenv_restore() to handle the temporary
instantiation of address environments, e.g. when a process is being
created.
Summary:
- I noticed that the hello (ELF) application causes a memory leak.
- Finally, I found that the data section is not deallocated.
- This commit fixes this issue.
Impact:
- ELF loader with CONFIG_ARCH_ADDRENV=n
Testing:
- Tested with the following configs
- sprensense:elf, esp32-devkitc:elf, sabre-6quad:elf
- spresense:wifi_smp, rv-virt:nsh64, sabre-6quad:netnsh
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Summary:
- I noticed that the hello (ELF) application causes a memory leak.
- Finally, I found that the data section is not deallocated.
- This commit fixes this issue.
Impact:
- None
Testing:
- Tested with spresense:wifi_smp, rv-virt:nsh64, sabre-6quad:netnsh
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Basically, mirror the following two commits from modlib.
It's shame we have two copies of elf loaders.
```
commit 51490bad55
Author: YAMAMOTO Takashi <yamamoto@midokura.com>
Date: Wed Apr 14 17:07:39 2021 +0900
modlib: Implement sh_addralign handling
I've seen a module with 16 bytes .rodata alignment for xmm operations.
It was getting SEGV on sim/Linux because of the alignment issue.
The same module binary seems working fine after applying this patch.
Also, tested on sim/macOS and esp32 on qemu,
using a module with an artificially large alignment. (64 bytes)
```
```
commit 418e11b8b3
Author: YAMAMOTO Takashi <yamamoto@midokura.com>
Date: Thu Apr 15 11:33:48 2021 +0900
modlib: Always use separate allocation for text and data
Pros:
* Reduce code differences
* Smaller allocations for !CONFIG_ARCH_USE_MODULE_TEXT
Cons:
* Likely to use more memory for !CONFIG_ARCH_USE_MODULE_TEXT in total
Tested with:
* sim:module on macOS
* esp32-devkit:nsh + CONFIG_MODULE on qemu
* lm3s6965-ek:qemu-protected + CONFIG_EXAMPLES_SOTEST on qemu
```
elf_init open a elf file , if both enabled
CONFIG_NSH_BUIlTAPPS and CONFIG_NSH_FILE_APPS ,
elf_init will read elf file in /bin directory, but
that length is zero , elf_read failed return and NOT
close elf fd, so this line MUST be return to errout_with_init
* include: Introduce elf64.h and elf.h
Added elf64.h for 64bit ELF support and moved common definitions
from elf32.h to elf.h. Also introduced Elf_xxx to be used in
common libraries such as binfmt.
* binfmt, include, modlib, module: Add support for ELF64
Elf_xxx must be used instead of Elf32_xxx to support ELF64.
To use ELF64, CONFIG_ELF_64BIT must be enabled.
* binfmt, modlib: Add support for relocate address
* arch: risc-v: Add include/elf.h
* libs: machine: Add risc-v related files.
NOTE: Currently only supports ELF64
* boards: maix-bit: Add elf and posix_spawn configurations
* boards: maix-bit: Add support for module configuration
* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
