linux(4): Add AT_MINSIGSTKSZ to arm64 port

MFC after: 2 weeks

linux(4): Implement signal trampoline for arm64 in a FreeBSD-way

The implemenation differs from others Linuxulators.
For unwinders Linux ucontext_t is stored, however native machine context
is used

linux(4): Implement signal trampoline for arm64 in a FreeBSD-way

The implemenation differs from others Linuxulators.
For unwinders Linux ucontext_t is stored, however native machine context
is used to store/restore process state to avoid code duplication.

As DWARF Aarch64 does not define a register number for PC and provides no
direct way to encode the PC of the previous frame, CFI cannot describe a
signal trampoline frame. So, modified the vdso linker script to discard
unused sections.

Extensions are not implemented.

MFC after: 2 weeks

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linux(4): Move sigframe definitions to separate headers

The signal trampoine-related definitions are used only in the MD part
of code, wherefore moved from everywhere used linux.h to separate MD
hea

linux(4): Move sigframe definitions to separate headers

The signal trampoine-related definitions are used only in the MD part
of code, wherefore moved from everywhere used linux.h to separate MD
headers.

MFC after: 2 weeks

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exec: Introduce the PROC_PS_STRINGS() macro

Rather than fetching the ps_strings address directly from a process'
sysentvec, use this macro. With stack address randomization the
ps_strings address i

exec: Introduce the PROC_PS_STRINGS() macro

Rather than fetching the ps_strings address directly from a process'
sysentvec, use this macro. With stack address randomization the
ps_strings address is no longer fixed.

Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33704

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sysent: Add a sv_psstringssz field to struct sysentvec

The size of the ps_strings structure varies between ABIs, so this is
useful for computing the address of the ps_strings structure relative to
t

sysent: Add a sv_psstringssz field to struct sysentvec

The size of the ps_strings structure varies between ABIs, so this is
useful for computing the address of the ps_strings structure relative to
the top of the stack when stack address randomization is enabled.

Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33704

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exec: Simplify sv_copyout_strings implementations a bit

Simplify control flow around handling of the execpath length and signal
trampoline. Cache the sysentvec pointer in a local variable.

No func

exec: Simplify sv_copyout_strings implementations a bit

Simplify control flow around handling of the execpath length and signal
trampoline. Cache the sysentvec pointer in a local variable.

No functional change intended.

Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33703

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linux(4): Remove unused arm64 SDT declarations

Those tracepoints have been removed somewhere in the past.

Sponsored By: EPSRC

syscall_args: remove MAXARGS define

Use nitems instead and just use a magic `8` for the size of the args
array. MAXARGS was rarely used (only in arm64 code) and is an overly
generic name to polute

syscall_args: remove MAXARGS define

Use nitems instead and just use a magic `8` for the size of the args
array. MAXARGS was rarely used (only in arm64 code) and is an overly
generic name to polute the namespace with.

Requested by: kib in D33308

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linux(4): Fix "set but not used" warnings

No functional changes.

Sponsored By: EPSRC

linux(4): Add struct clone_args for future clone3 system call.

In preparation for clone3 system call add struct clone_args and use it in
clone implementation.
Move all of clone related bits to the n

linux(4): Add struct clone_args for future clone3 system call.

In preparation for clone3 system call add struct clone_args and use it in
clone implementation.
Move all of clone related bits to the newly created linux_fork.h header.

Differential revision: https://reviews.freebsd.org/D31474
MFC after: 2 weeks

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linux: implement signal delivery on arm64

Note that this still uses FreeBSD-style sigframe;
this will be addressed later.

Reviewed By: dchagin
Sponsored By: EPSRC
Differential Revision: https://rev

linux: implement signal delivery on arm64

Note that this still uses FreeBSD-style sigframe;
this will be addressed later.

Reviewed By: dchagin
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D31258

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linux(4): Add arch name to the some printfs.

Reviewed by: emaste
Differential revision: https://reviews.freebsd.org/D30904
MFC after: 2 weeks

linux(4): Fixup the vDSO initialization order.

The vDSO initialisation order should be as follows:
- native abi init via exec_sysvec_init();
- vDSO symbols queued to the linux_vdso_syms list;
- linu

linux(4): Fixup the vDSO initialization order.

The vDSO initialisation order should be as follows:
- native abi init via exec_sysvec_init();
- vDSO symbols queued to the linux_vdso_syms list;
- linux_vdso_install();
- linux_exec_sysvec_init();

As the exec_sysvec_init() called with SI_ORDER_ANY (last) at SI_SUB_EXEC
order, move linux_vdso_install() and linux_exec_sysvec_init() to the
SI_SUB_EXEC+1 order.

Reviewed by: trasz
Differential Revision: https://reviews.freebsd.org/D30902
MFC after 2 weeks

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linux(4); Almost complete the vDSO.

The vDSO (virtual dynamic shared object) is a small shared library that the
kernel maps R/O into the address space of all Linux processes on image
activation. The

linux(4); Almost complete the vDSO.

The vDSO (virtual dynamic shared object) is a small shared library that the
kernel maps R/O into the address space of all Linux processes on image
activation. The vDSO is a fully formed ELF image, shared by all processes
with the same ABI, has no process private data.

The primary purpose of the vDSO:
- non-executable stack, signal trampolines not copied to the stack;
- signal trampolines unwind, mandatory for the NPTL;
- to avoid contex-switch overhead frequently used system calls can be
implemented in the vDSO: for now gettimeofday, clock_gettime.

The first two have been implemented, so add the implementation of system
calls.

System calls implemenation based on a native timekeeping code with some
limitations:
- ifunc can't be used, as vDSO r/o mapped to the process VA and rtld
can't relocate symbols;
- reading HPET memory is not implemented for now (TODO).

In case on any error vDSO system calls fallback to the kernel system
calls. For unimplemented vDSO system calls added prototypes which call
corresponding kernel system call.

Tested by: trasz (arm64)
Differential revision: https://reviews.freebsd.org/D30900
MFC after: 2 weeks

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linux(4): Modify sv_onexec hook to return an error.

Temporary add stubs to the Linux emulation layer which calls the existing hook.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.

linux(4): Modify sv_onexec hook to return an error.

Temporary add stubs to the Linux emulation layer which calls the existing hook.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D30911
MFC after: 2 weeks

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Pass the syscall number to capsicum permission-denied signals

The syscall number is stored in the same register as the syscall return
on amd64 (and possibly other architectures) and so it is impossi

Pass the syscall number to capsicum permission-denied signals

The syscall number is stored in the same register as the syscall return
on amd64 (and possibly other architectures) and so it is impossible to
recover in the signal handler after the call has returned. This small
tweak delivers it in the `si_value` field of the signal, which is
sufficient to catch capability violations and emulate them with a call
to a more-privileged process in the signal handler.

This reapplies 3a522ba1bc852c3d4660a4fa32e4a94999d09a47 with a fix for
the static assertion failure on i386.

Approved by: markj (mentor)

Reviewed by: kib, bcr (manpages)

Differential Revision: https://reviews.freebsd.org/D29185

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linux(4): remove unfinished vsyscall bits on arm64

The vsyscall mechanism is obsolete.

Reviewed By: dchagin, emaste
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D31091

Revert "Pass the syscall number to capsicum permission-denied signals"

This broke the i386 build.

This reverts commit 3a522ba1bc852c3d4660a4fa32e4a94999d09a47.

Pass the syscall number to capsicum permission-denied signals

The syscall number is stored in the same register as the syscall return
on amd64 (and possibly other architectures) and so it is impossi

Pass the syscall number to capsicum permission-denied signals

The syscall number is stored in the same register as the syscall return
on amd64 (and possibly other architectures) and so it is impossible to
recover in the signal handler after the call has returned. This small
tweak delivers it in the `si_value` field of the signal, which is
sufficient to catch capability violations and emulate them with a call
to a more-privileged process in the signal handler.

Approved by: markj (mentor)

Reviewed by: kib, bcr (manpages)

Differential Revision: https://reviews.freebsd.org/D29185

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linux(4): implement coredumps on arm64

Previously they only worked on amd64.

Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30975

linux(4): revert arm64 part of 447636e43c0

The arm64 part of the patch was incomplete and prevented
linux64.ko from loading due to missing symbol.

Sponsored By: EPSRC

linux(4): implement coredump support

Implement dumping core for Linux binaries on amd64, for both
32- and 64-bit executables. Some bits are still missing.

This is based on a prototype by chuck@.

linux(4): implement coredump support

Implement dumping core for Linux binaries on amd64, for both
32- and 64-bit executables. Some bits are still missing.

This is based on a prototype by chuck@.

Reviewed By: kib
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30019

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Add infrastructure required for Linux coredump support

This adds `sv_elf_core_osabi`, `sv_elf_core_abi_vendor`,
and `sv_elf_core_prepare_notes` fields to `struct sysentvec`,
and modifies imgact_elf.

Add infrastructure required for Linux coredump support

This adds `sv_elf_core_osabi`, `sv_elf_core_abi_vendor`,
and `sv_elf_core_prepare_notes` fields to `struct sysentvec`,
and modifies imgact_elf.c to make use of them instead
of hardcoding FreeBSD-specific values. It also updates all
of the ABI definitions to preserve current behaviour.

This makes it possible to implement non-native ELF coredump
support without unnecessary code duplication. It will be used
for Linux coredumps.

Reviewed By: kib
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30921

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linux(4): Retire linux_kplatform.

Assuming we can't run on i486, i586 class cpu, retire linux_kplatform var
and use hardcoded 'machine' value in linux_newuname().

I have added linux_kplatform for c

linux(4): Retire linux_kplatform.

Assuming we can't run on i486, i586 class cpu, retire linux_kplatform var
and use hardcoded 'machine' value in linux_newuname().

I have added linux_kplatform for consistency with linux_platform which is
placed in to vdso to avoid excess copyout it on stack for AT_PLATFORM at
exec time.

This is the first stage of Linuxulator's vdso revision.

Reviewed by: trasz, imp
Differential Revision: https://reviews.freebsd.org/D30774
MFC after: 2 weeks

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Add quirks for Linux ABI signals handling

Require queueing of the signals with default action, and disable
dequeueing SIGCHLD on wait for live process.

Reported and tested by: dchagin
Reviewed by:

Add quirks for Linux ABI signals handling

Require queueing of the signals with default action, and disable
dequeueing SIGCHLD on wait for live process.

Reported and tested by: dchagin
Reviewed by: dchagin, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D30675

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