Linux ARM v2 3/9

[emaste]

Test Plan

Linux ARM : Add syscalls definition from arch/arm/kernel/calls.S (linux sources)

[imp]

sys/arm/linux/syscalls.master

677

This is the only unimplemented one that I'm at all worried about.... Have you encountered any programs that use it?

[andrew]

sys/arm/linux/syscalls.master

49–50

This doesn't exist in Linux 2.6.32.

66–67

Also missing in 2.6.32

80–81

Also missing in 2.6.32

102–103

Also missing in 2.6.32

116

Also missing in 2.6.32

128–129

Also missing in 2.6.32

159

Also missing in 2.6.32

202

Also missing in 2.6.32

230

Also missing in 2.6.32

233

Also missing in 2.6.32

295–296

Also missing in 2.6.32

677

This range is also invalid, the syscalls start at 0x0f0000 and not 400

[soutade_gmail.com]

sys/arm/linux/syscalls.master

49–50

It all has been extracted and checked from Linux 4.7.

677

Not for now. Maybe some glibc flush functions could use it, but I'm not sure.

677

This is handled in linux_fetch_syscall_args() to avoid breaking syscall numbering.

[andrew]

sys/arm/linux/syscalls.master

49–50

None of the syscalls I pointed out exist in my recent git checkout.

677

In that case a comment would help.

[soutade_gmail.com]

Add more comments for ARM specific syscalls

[soutade_gmail.com]

sys/arm/linux/syscalls.master

49–50

They are marked as "sys_ni_syscall", but I decied to use the old value if it exists (for old kernel ABI)

[andrew]

There are also a few syscalls that were removed when they changed to EABI. I don't see a need for us to support the syscalls userspace will never call.

sys/arm/linux/syscalls.master

49–50

Linux hasn't supported them in a non-development kernel since 2.6. This was released in late 2003.

207

This is wrong, on arm this is the syscall syscall (although it's removed from EABI).

[soutade_gmail.com]

In D7972#167400, @andrew wrote:

There are also a few syscalls that were removed when they changed to EABI. I don't see a need for us to support the syscalls userspace will never call.

Should we also support OBSOLETE syscalls ? It seems related to OABI.

[soutade_gmail.com]

Remove old Linux syscalls (not presents in Linux calls.S). Add dummy linux_syscall.

[andrew]

Syscalls 13 (time), 22 (umount), 25 (stime), 27 (alarm), 30 (utime), 76 (getrlimir), 82 (select), 89 (readdir), 90 (mmap), 102 (socketcall), 113 (syscall), and 117 (ipc) dont seem to be exported to userspace. I would expect the only things that try calling these with the EABI are malicious.

sys/arm/linux/syscalls.master

290

vm86 should be removed.

294

Why was? It seems to be implemented in Linux.

[soutade_gmail.com]

sys/arm/linux/syscalls.master

290

I forgot it !

294

I use this file https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/kernel/calls.S as base, and it's currently not implemented

[soutade_gmail.com]

sys/arm/linux/syscalls.master

294

What about OBSOLETE syscalls ? Keep them or remove them ?

[andrew]

sys/arm/linux/syscalls.master

294

I've been looking through https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/include/uapi/asm/unistd.h to find the syscalls.

The OBSOLETE syscalls are marked as not implemented by https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/kernel/entry-common.S#n294

[soutade_gmail.com]

sys/arm/linux/syscalls.master

294

OK. I think the same thing, but I wanted to be sure before commit another patch.

[soutade_gmail.com]

Remove obsolete syscalls. Add linux_send() and linux_recv()

[brooks]

Since this is a new file, you might want to consider formatting it in the new, more readable style used in sys/kern/syscalls.master.

[emaste]

We'll also want to switch this to the new style -- see rS347186 for arm64.

[emaste]

Oh I see @brooks already mentioned that.

[emaste]

Reformat arm linux syscalls.master per current style

Equivalent to rS339958 for sys/kern/syscalls.master.

Sponsored by: The FreeBSD Foundation