[PATCH v5 00/23] ILP32 for ARM64

From: Yury Norov
Date: Tue Sep 29 2015 - 18:15:05 EST

V5 reincarnation for ILP32.

This is mostly the same code as Andrew suggested in v3:
https://lkml.org/lkml/2014/9/3/704.

V4 series and discussion:
https://lkml.org/lkml/2015/4/13/691

Discussion on v3 and v4 raised questions and some disagreement in community,
and therefore patches are not accepted till now. In this v5 I tried to avoid any
changes that are not about obvious fixes, so all interface and implementation
questions are still here.

In v5:
- rebased on top of 4.3.0-rc3;
- build fixed if ILP32 enabled without AARCH32;
- PATCH v4 22/24 (use compat for stack_t) dropped because it confuses
debug tools like gdb and strace;
- PATCH v4 20/24 (use compat-syscalls for msgsnd and msgrcv for ILP32)
dropped as breaking tests;
- PATCH v5 22/23 (msgrcv, msgsnd handlers) introduced for proper
handling of msgrcv, msgsnd;
- other minor fixes.

Questions under discussion:
- What for ILP32 on ARM64?
See https://lkml.org/lkml/2015/4/13/814
and http://permalink.gmane.org/gmane.comp.lib.uclibc.buildroot/121100
Briefly,
- for compatibility;
- for performance;
- for memory saving.

- ABI questions: time_t and so on;
I think we are out of choice now. Patches to GCC and Glibc are
upstreamed more than a year ago, and there already might be a code compiled
against existing ABI. At the end, there is no major disagreement, and final
word is after ABI users. And I found no objections from that side.

- Implementation questions: use ILP32 separated table or not, and others;
Code proposed by Andrew works just fine for more than a year,
and it even shows slightly better performance comparing to LP64:
http://permalink.gmane.org/gmane.comp.lib.uclibc.buildroot/121100
So I see no reason to change something except obvious bugs, if found.

Andrew Pinski (18):
arm64: ensure the kernel is compiled for LP64
arm64: rename COMPAT to AARCH32_EL0 in Kconfig
arm64: change some CONFIG_COMPAT over to use CONFIG_AARCH32_EL0
instead
arm64:ilp32: expose 'kernel_long' as 'long long' for ILP32
arm64:uapi: set __BITS_PER_LONG correctly for ILP32 and LP64
arm64:ilp32: share signal structures between ILP32 and LP64 ABIs
arm64:ilp32: use 64bit syscall-names for ILP32 when passing 64bit
registers
arm64:ilp32: use non-compat syscall names for ILP32 as for LP64
arm64: introduce is_a32_task and is_a32_thread (for AArch32 compat)
arm64:ilp32: add is_ilp32_compat_{task,thread} and TIF_32BIT_AARCH64
arm64:ilp32: share HWCAP between LP64 and ILP32
arm64:ilp32 use the native LP64 'start_thread' for ILP32 threads
arm64:ilp32: support core dump generation for ILP32
arm64: add support for starting ILP32 (ELFCLASS32) binaries
ptrace: Allow compat to use the native siginfo
arm64:ilp32: add sys_ilp32.c and a separate table (in entry.S) to use
it
arm64:ilp32: use the native siginfo instead of the compat siginfo
arm64:ilp32: add ARM64_ILP32 to Kconfig

Philipp Tomsich (4):
arm64:ilp32: add documentation on the ILP32 ABI for ARM64
arm64:ilp32: COMPAT_USE_64BIT_TIME is true for ILP32 tasks
arm64:ilp32: add vdso-ilp32 and use for signal return
arm64:ilp32: change COMPAT_ELF_PLATFORM to report a a subplatform for
ILP32

Yury Norov (1):
aarch64: ilp32: msgrcv, msgsnd handlers

Documentation/arm64/ilp32.txt | 64 ++++++
arch/arm64/Kconfig | 14 +-
arch/arm64/Makefile | 6 +-
arch/arm64/include/asm/compat.h | 65 +++++-
arch/arm64/include/asm/elf.h | 105 ++++++++--
arch/arm64/include/asm/fpsimd.h | 2 +-
arch/arm64/include/asm/hwcap.h | 12 +-
arch/arm64/include/asm/memory.h | 2 +-
arch/arm64/include/asm/processor.h | 12 +-
arch/arm64/include/asm/ptrace.h | 2 +-
arch/arm64/include/asm/signal32.h | 2 +
arch/arm64/include/asm/stat.h | 2 +
arch/arm64/include/asm/thread_info.h | 3 +-
arch/arm64/include/asm/unistd.h | 8 +-
arch/arm64/include/asm/vdso.h | 4 +
arch/arm64/include/uapi/asm/bitsperlong.h | 9 +-
arch/arm64/include/uapi/asm/posix_types.h | 12 +-
arch/arm64/include/uapi/asm/siginfo.h | 21 ++
arch/arm64/include/uapi/asm/signal.h | 32 +++
arch/arm64/include/uapi/asm/unistd.h | 7 +
arch/arm64/kernel/Makefile | 8 +-
arch/arm64/kernel/asm-offsets.c | 2 +-
arch/arm64/kernel/entry.S | 18 +-
arch/arm64/kernel/head.S | 2 +-
arch/arm64/kernel/hw_breakpoint.c | 6 +-
arch/arm64/kernel/process.c | 4 +-
arch/arm64/kernel/ptrace.c | 51 +++--
arch/arm64/kernel/signal.c | 23 ++-
arch/arm64/kernel/sys_ilp32.c | 223 +++++++++++++++++++++
arch/arm64/kernel/traps.c | 4 +-
arch/arm64/kernel/vdso-ilp32/.gitignore | 2 +
arch/arm64/kernel/vdso-ilp32/Makefile | 72 +++++++
.../siginfo.h => kernel/vdso-ilp32/vdso-ilp32.S} | 22 +-
arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S | 98 +++++++++
arch/arm64/kernel/vdso.c | 73 +++++--
include/linux/compat.h | 4 +
include/uapi/asm-generic/siginfo.h | 17 +-
include/uapi/asm-generic/signal.h | 27 ++-
include/uapi/asm-generic/unistd.h | 5 +-
kernel/ptrace.c | 24 ++-
40 files changed, 973 insertions(+), 96 deletions(-)
create mode 100644 Documentation/arm64/ilp32.txt
create mode 100644 arch/arm64/kernel/sys_ilp32.c
create mode 100644 arch/arm64/kernel/vdso-ilp32/.gitignore
create mode 100644 arch/arm64/kernel/vdso-ilp32/Makefile
copy arch/arm64/{include/uapi/asm/siginfo.h => kernel/vdso-ilp32/vdso-ilp32.S} (60%)
create mode 100644 arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S

--
2.1.4

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