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
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
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
This makes it easier to compare the two. This involves moving
the mutex slightly lower down, but there should be no functional
changes.
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30541
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
instead of manually inlining it
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29687
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
The former clobbers some registers that shouldn't be touched.
Reviewed by: kib (earlier version)
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26406
Since LA57 was moved to the main SDM document with revision 072, it
seems that we should have a support for it, and silicons are coming.
This patch makes pmap support both LA48 and LA57 hardware. The
selection of page table level is done at startup, kernel always
receives control from loader with 4-level paging. It is not clear how
UEFI spec would adapt LA57, for instance it could hand out control in
LA57 mode sometimes.
To switch from LA48 to LA57 requires turning off long mode, requesting
LA57 in CR4, then re-entering long mode. This is somewhat delicate
and done in pmap_bootstrap_la57(). AP startup in LA57 mode is much
easier, we only need to toggle a bit in CR4 and load right value in CR3.
I decided to not change kernel map for now. Single PML5 entry is
created that points to the existing kernel_pml4 (KML4Phys) page, and a
pml5 entry to create our recursive mapping for vtopte()/vtopde().
This decision is motivated by the fact that we cannot overcommit for
KVA, so large space there is unusable until machines start providing
wider physical memory addressing. Another reason is that I do not
want to break our fragile autotuning, so the KVA expansion is not
included into this first step. Nice side effect is that minidumps are
compatible.
On the other hand, (very) large address space is definitely
immediately useful for some userspace applications.
For userspace, numbering of pte entries (or page table pages) is
always done for 5-level structures even if we operate in 4-level mode.
The pmap_is_la57() function is added to report the mode of the
specified pmap, this is done not to allow simultaneous 4-/5-levels
(which is not allowed by hw), but to accomodate for EPT which has
separate level control and in principle might not allow 5-leve EPT
despite x86 paging supports it. Anyway, it does not seems critical to
have 5-level EPT support now.
Tested by: pho (LA48 hardware)
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D25273
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
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
