[PATCH v2 0/2] Embedding Position Independent Executables

Alexandre Belloni alexandre.belloni at free-electrons.com
Tue Jun 28 15:44:44 PDT 2016


Hi,

This series introduces Position Independent Executables (PIEs) for the
ARM architecture.
The main goal is to avoid having to write low level code in assembly as
this is currently the case for suspend/resume. Multiple platforms will
benefit from this infrastructure: at91, rockchip, sunxi, am335x.

Changes in v2:
 - handle big endian
 - handle gcov and ftrace by disabling them before compilling the PIE
 - Get the alignment from the original ELF to ensure the PIE is
   properly aligned in SRAM.
 - stop using fncpy
 - rebased on v4.7-rc1

I've still avoided using the ELF header itself to be more efficient.
For example, for atmel, the PIE is 66772 bytes when embedded in an ELF
versus 344 bytes standalone. This is working properly because the PIE
is self standing and correctly padded.

Alexandre Belloni (2):
  ARM: PIE infrastructure
  ARM: at91: pm: switch to the PIE infrastructure

 arch/arm/Kconfig                 |   2 +
 arch/arm/Makefile                |   1 +
 arch/arm/mach-at91/Kconfig       |   1 +
 arch/arm/mach-at91/Makefile      |   2 +-
 arch/arm/mach-at91/pm.c          |  31 ++--
 arch/arm/mach-at91/pm/.gitignore |   2 +
 arch/arm/mach-at91/pm/Makefile   |   3 +
 arch/arm/mach-at91/pm/atmel_pm.c |  97 +++++++++++
 arch/arm/mach-at91/pm_suspend.S  | 338 ---------------------------------------
 arch/arm/pie/Kconfig             |   8 +
 arch/arm/pie/Makefile            |   1 +
 arch/arm/pie/Makefile.pie        |  86 ++++++++++
 arch/arm/pie/lib/empty.c         |  15 ++
 arch/arm/pie/pie.c               |  97 +++++++++++
 arch/arm/pie/pie.lds.S           |  40 +++++
 include/linux/pie.h              | 146 +++++++++++++++++
 16 files changed, 510 insertions(+), 360 deletions(-)
 create mode 100644 arch/arm/mach-at91/pm/.gitignore
 create mode 100644 arch/arm/mach-at91/pm/Makefile
 create mode 100644 arch/arm/mach-at91/pm/atmel_pm.c
 delete mode 100644 arch/arm/mach-at91/pm_suspend.S
 create mode 100644 arch/arm/pie/Kconfig
 create mode 100644 arch/arm/pie/Makefile
 create mode 100644 arch/arm/pie/Makefile.pie
 create mode 100644 arch/arm/pie/lib/empty.c
 create mode 100644 arch/arm/pie/pie.c
 create mode 100644 arch/arm/pie/pie.lds.S
 create mode 100644 include/linux/pie.h

-- 
2.8.1




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