Due to fxsave area is os independent reimplement fxsave handmade code
using copying of a whole area.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D40443
MFC after: 2 weeks
Perhaps, this does not makes much sense as destroyng %rcx declared by
the x86_64 Linux syscall ABI. However,:
a) if we get a signal while we are in the kernel, we should restore
tf_rcx when preparing machine context for signal handlers.
b) the Linux world is strange, someone can depend on %rcx value
after syscall, something like go.
Differential Revision: https://reviews.freebsd.org/D40155
MFC after: 1 month
I agree, it would be great to avoid PCB_FULL_IRET, however we should
follow Linux system call ABI.
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D40152
MFC after: 1 month
Export default MINSIGSTKSZ value for the x86 until we do not preserve AVX
registers in the signal context.
Differential Revision: https://reviews.freebsd.org/D39644
MFC after: 1 month
Use native routines to fixup initial process stack. On Arm64 linux_elf_fixup() is
noop, as it do the stack fixup (room for argc) in the linux_copyout_strings().
MFC after: 1 week
This allows the syscallname() function to give a usable result for Linux
ABIs.
Reported by: jrtc27
Reviewed by: jrtc27, markj, jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D37199
Store the shared page address in struct vmspace.
Also instead of storing absolute addresses of various shared page
segments save their offsets with respect to the shared page address.
This will be more useful when the shared page address is randomized.
Approved by: mw(mentor)
Sponsored by: Stormshield
Obtained from: Semihalf
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D35393
On amd64 Linux saves the thread signal mask in both contexts, in the machine
dependent and in the machine independent. Both contexts are user accessible.
Convert the mask once, then copy it.
MFC after: 2 weeks
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
This is the first stage of a signal trampolines refactoring.
From trampolines retired emulation of the 'call' instruction, which is
replaced by direct call of a signal handler. The signal handler address
is in the register.
The previous trampoline implemenatation used semi-Linux-way to call
a signal handler via the 'jmp' instruction. Wherefore the trampoline
emulated a 'call' instruction to into the stack the return address for
signal handler's 'ret' instruction. Wherefore handmade DWARD annotations
was used.
While here rephrased and removed excessive comments.
MFC after: 2 weeks
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
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
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
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
At least Linux x86 ABI's does not use carry bit and expects that the dx register
is preserved. For this add a new sv_set_fork_retval hook and call it from cpu_fork().
Add a short comment about touching dx in x86_set_fork_retval(), for more details
see phab comments from kib@ and imp@.
Reviewed by: kib
Differential revision: https://reviews.freebsd.org/D31472
MFC after: 2 weeks
To determine whether to use alternate signal stack or not,
we need to use the native signal number, not the one translated
with bsd_to_linux_signal().
In practical terms, this fixes golang.
Reviewed By: dchagin
Fixes: 135dd0cab5
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D31298
Initial patch from submitter was adapted by me to prevent unconditional
FUTEX_REQUEUE use.
PR: 255947
Submitted by: Philippe Michaud-Boudreault
Differential Revision: https://reviews.freebsd.org/D30332
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
In order to reduce diff between arches constify vdso install/deinstall
functions like arm64.
Reviewed by: emaste
Differential revision: https://reviews.freebsd.org/D30901
MFC after: 2 weeks
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
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
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 3a522ba1bc 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
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
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
