| From: |
| Nicolas Pitre <nicolas.pitre@linaro.org> |
| To: |
| linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org |
| Subject: |
| [PULL REQUEST] [PATCH v2 00/10] allow BFLT executables on systems with a MMU |
| Date: |
| Sun, 17 Jul 2016 23:31:46 -0400 |
| Message-ID: |
| <1468812716-30537-1-git-send-email-nicolas.pitre@linaro.org> |
| Cc: |
| Alexander Viro <viro@zeniv.linux.org.uk>, David Howells <dhowells@redhat.com>, Greg Ungerer <gerg@linux-m68k.org> |
| Archive‑link: | |
Article |
This series provides the necessary changes to allow "flat" executable
binaries meant for no-MMU systems to actually run on systems with a MMU.
This can also be found in the following git repo:
git://git.linaro.org/people/nicolas.pitre/linux binfmt_flat_with_mmu
*Why?*
Because developing and testing natively on a large system with lots of
RAM makes it so much more convenient to use all the existing profiling
tools and debugging facilities that a kernel with lots of RAM can give.
And incidentally, those systems with lots of RAM all have a MMU.
*Why not use elf_fdpic?*
The flat executable format is simple with very small footprint
overhead, either in the executables themselves or kernel support.
This makes the flat format more suitable than elf_fdpic for very small
single-user-app embedded systems.
And while elf_fdpic binaries can run on MMU systems, flat binaries still
couldn't, which just felt wrong.
So here it is. The no-MMU support should remain unaffected. Please consider
for pulling.
Tested on ARM only with a busybox build.
Changes since v1:
- Removed SuperH and Xtensa from the Kconfig rule as they fail to build
due to lack of get/put_unaligned_user().
- Clarified some commit logs a bit.
diffstat:
arch/arm/include/asm/flat.h | 5 +-
arch/m68k/include/asm/flat.h | 5 +-
fs/Kconfig.binfmt | 3 +-
fs/binfmt_elf_fdpic.c | 38 +---
fs/binfmt_flat.c | 372 +++++++++++++++++++++--------------
fs/exec.c | 33 ++++
include/linux/binfmts.h | 2 +
7 files changed, 268 insertions(+), 190 deletions(-)