Replace sigframe sf_extramask by native sigset_t and use it to
store/restore the thread signal mask without conversion to/from
Linux signal mask.
Pointy hat to: dchagin
MFC after: 2 weeks
The Linux exports __kernel_sigreturn and __kernel_rt_sigreturn from the
vdso. Modern glibc's sigaction sets the sa_restorer field of sigaction
to the corresponding vdso __sigreturn, and sets the SA_RESTORER.
Our signal trampolines uses the FreeBSD-way to call a signal handler,
so does not use the sigaction's sa_restorer.
However, as glibc's runtime linker depends on the existment of the vdso
__sigreturn symbols, for all Linuxulators was added separate trampolines
named __sigcode with DWARF anotations and left separate __sigreturn
methods, which are exported.
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
Both uc_flags and uc_link are zeroed above. On amd64 and i386 the
uc_link field is not used at all. The UC_FP_XSTATE bit should be set
in the uc_flags if OS xsave knob is turned on (and xsave is implemented).
MFC after: 2 weeks
Historically 32-bit Linuxulator under amd64 emulated the real i386
behavior. Since 3d8dd983 the old i386 Linux world can't be used under
amd64 Linuxulator as it don't know anything about amd64 machine (which
is returned now by newuname() syscall). So, add a knob to allow to swith
the behavior and use i386 Linux binaries on amd64.
Set knob to the new behavior as I think this is common to the modern
Linux distros.
Reviewed by: Pau Amma (doc), emaste
Differential revision: https://reviews.freebsd.org/D34708
MFC after: 2 weeks
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
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
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
Hide the vDSO defines to the linux32_sysvec as they are not intended to
be used outside of it. Fix LINUX32_PS_STRINGS, use the size of
struct linux32_ps_strings instead of a numeric constant.
MFC after: 2 weeks
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
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
Retire ksiginfo_to_lsiginfo function, use siginfo_to_lsiginfo instead.
Convert rt_sigtimedwait siginfo variables to well known names.
MFC after: 2 weeks
This should be a no-op; the purpose of this is to reduce
a spurious difference between Linuxulator and Linux, to make
debugging core dumps slightly easier.
Note that AT_HWCAP2 we pass to Linux binaries is always 0,
instead of being equal to 'cpu_feature2'. This matches what
I've observed under Ubuntu Focal VM.
Reviewed By: chuck, dchagin
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D29609
linux_shared_page_init() creates an object and grabs and maps a single
page to back the VDSO. When destroying the VDSO object, we failed to
destroy the mapping and free KVA. Fix this.
Reviewed by: kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D28696
Use AUXARGS_ENTRY_PTR to export these pointers. This is a followup to
r359987 and r359988.
Reviewed by: jhb
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D24446
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT
Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718
than "/compat/linux". Useful when you have several compat directories
with different Linux versions and you don't want to clash with files
installed by linux-c7 packages.
Reviewed by: bcr (manpages)
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D22574
Partially revert r354741 and r354754 and go back to allocating a
fixed-size chunk of stack space for the auxiliary vector. Keep
sv_copyout_auxargs but change it to accept the address at the end of
the environment vector as an input stack address and no longer
allocate room on the stack. It is now called at the end of
copyout_strings after the argv and environment vectors have been
copied out.
This should fix a regression in r354754 that broke the stack alignment
for newer Linux amd64 binaries (and probably broke Linux arm64 as
well).
Reviewed by: kib
Tested on: amd64 (native, linux64 (only linux-base-c7), and i386)
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D22695
- Use ustringp for the location of the argv and environment strings
and allow destp to travel further down the stack for the stackgap
and auxv regions.
- Update the Linux copyout_strings variants to move destp down the
stack as was done for the native ABIs in r263349.
- Stop allocating a space for a stack gap in the Linux ABIs. This
used to hold translated system call arguments, but hasn't been used
since r159992.
Reviewed by: kib
Tested on: md64 (amd64, i386, linux64), i386 (i386, linux)
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D22501
