sysent: Add sv_protect

To allow for architecture specific protections add sv_protect to struct
sysent. This can be used to apply these after the executable is loaded
into the new address space.

Rev

sysent: Add sv_protect

To allow for architecture specific protections add sv_protect to struct
sysent. This can be used to apply these after the executable is loaded
into the new address space.

Reviewed by: kib
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D42440

show more ...

sysent: Trim trailing whitespaces

MFC after: 1 week

sysentvec: add SV_SIGSYS flag

to allow ABIs to indicate that SIGSYS is needed. Mark all native
FreeBSD ABIs with the flag.

This implicitly marks Linux' ABIs as not delivering SIGSYS on invalid
sys

sysentvec: add SV_SIGSYS flag

to allow ABIs to indicate that SIGSYS is needed. Mark all native
FreeBSD ABIs with the flag.

This implicitly marks Linux' ABIs as not delivering SIGSYS on invalid
syscall.

Reviewed by: dchagin, markj
Discussed with: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D41976

show more ...

syscalls: fix missing SIGSYS for several ENOSYS errors

In particular, when the syscall number is too large, or when syscall is
dynamic. For that, add nosys_sysent structure to pass fake sysent to
s

syscalls: fix missing SIGSYS for several ENOSYS errors

In particular, when the syscall number is too large, or when syscall is
dynamic. For that, add nosys_sysent structure to pass fake sysent to
syscall top code.

Reviewed by: dchagin, markj
Discussed with: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D41976

show more ...

sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

sysentvec: Retire sv_imgact_try as unneeded anymore

The sysentvec sv_imgact_try was used by kern_exec() to allow
non-native ABI to fixup shell path according to ABI root directory.
Since the non-nat

sysentvec: Retire sv_imgact_try as unneeded anymore

The sysentvec sv_imgact_try was used by kern_exec() to allow
non-native ABI to fixup shell path according to ABI root directory.
Since the non-native ABI can now specify its root directory directly
to namei() via pwd_altroot() call this facility is not needed anymore.

Differential Revision: https://reviews.freebsd.org/D40092
MFC after: 2 month

show more ...

Rework how shared page related data is stored

Store the shared page address in struct vmspace.
Also instead of storing absolute addresses of various shared page
segments save their offsets with resp

Rework how shared page related data is stored

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

show more ...

Retire sv_transtrap

Call translate_traps directly from sendsig().

MFC after: 2 weeks

Add PT_GETREGSET

This adds the PT_GETREGSET and PT_SETREGSET ptrace types. These can be
used to access all the registers from a specified core dump note type.
The NT_PRSTATUS and NT_FPREGSET notes a

Add PT_GETREGSET

This adds the PT_GETREGSET and PT_SETREGSET ptrace types. These can be
used to access all the registers from a specified core dump note type.
The NT_PRSTATUS and NT_FPREGSET notes are initially supported. Other
machine-dependant types are expected to be added in the future.

The ptrace addr points to a struct iovec pointing at memory to hold the
registers along with its length. On success the length in the iovec is
updated to tell userspace the actual length the kernel wrote or, if the
base address is NULL, the length the kernel would have written.

Because the data field is an int the arguments are backwards when
compared to the Linux PTRACE_GETREGSET call.

Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19831

show more ...

exec: Remove the stack gap implementation

ASLR stack randomization will reappear in a forthcoming commit. Rather
than inserting a random gap into the stack mapping, the entire stack
mapping itself

exec: Remove the stack gap implementation

ASLR stack randomization will reappear in a forthcoming commit. Rather
than inserting a random gap into the stack mapping, the entire stack
mapping itself will be randomized in the same way that other mappings
are when ASLR is enabled.

No functional change intended, as the stack gap implementation is
currently disabled by default.

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

show more ...

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

show more ...

Pass vdso address to userspace

Reviewed by: emaste
Discussed with: jrtc27
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D3

Pass vdso address to userspace

Reviewed by: emaste
Discussed with: jrtc27
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D32960

show more ...

amd64: wrap 64bit sigtramp into vdso

Reviewed by: emaste
Discussed with: jrtc27
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.

amd64: wrap 64bit sigtramp into vdso

Reviewed by: emaste
Discussed with: jrtc27
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D32960

show more ...

syscalls: make syscall and __syscall SYSMUX

Rather than combining the declearation of nosys with the registration
of SYS_syscall, declare syscall(2) and __syscall(2) with the new
SYSMUX type in sysc

syscalls: make syscall and __syscall SYSMUX

Rather than combining the declearation of nosys with the registration
of SYS_syscall, declare syscall(2) and __syscall(2) with the new
SYSMUX type in syscalls.master and declare nosys directly. This
eliminates the last use of syscall aliases in the tree.

Reviewed by: kib, imp

show more ...

Unmap shared page manually before doing vm_map_remove() on exit or exec

This allows the pmap_remove(min, max) call to see empty pmap and exploit
empty pmap optimization.

Reviewed by: markj
Tested b

Unmap shared page manually before doing vm_map_remove() on exit or exec

This allows the pmap_remove(min, max) call to see empty pmap and exploit
empty pmap optimization.

Reviewed by: markj
Tested by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32569

show more ...

setrlimit: Take stack gap into account.

Calling setrlimit with stack gap enabled and with low values of stack
resource limit often caused the program to abort immediately after
exiting the syscall.

setrlimit: Take stack gap into account.

Calling setrlimit with stack gap enabled and with low values of stack
resource limit often caused the program to abort immediately after
exiting the syscall. This happened due to the fact that the resource
limit was calculated assuming that the stack started at sv_usrstack,
while with stack gap enabled the stack is moved by a random number
of bytes.

Save information about stack size in struct vmspace and adjust the
rlim_cur value. If the rlim_cur and stack gap is bigger than rlim_max,
then the value is truncated to rlim_max.

PR: 253208
Reviewed by: kib
Obtained from: Semihalf
Sponsored by: Stormshield
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D31516

show more ...

Remove SV_CAPSICUM

It was only needed for cloudabi

Reviewed by: emaste
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D31923

Drop cloudabi

According to https://github.com/NuxiNL/cloudlibc:
CloudABI is no longer being maintained. It was an awesome experiment,
but it never got enough traction to be sustainable.

There is no

Drop cloudabi

According to https://github.com/NuxiNL/cloudlibc:
CloudABI is no longer being maintained. It was an awesome experiment,
but it never got enough traction to be sustainable.

There is no reason to keep it in FreeBSD.

Approved by: ed (private mail)
Reviewed by: emaste
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D31923

show more ...

fork: Allow ABI to specify fork return values for child.

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

fork: Allow ABI to specify fork return values for child.

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

show more ...

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

show more ...

Do not call FreeBSD-ABI specific code for all ABIs

Use sysentvec hooks to only call umtx_thread_exit/umtx_exec, which handle
robust mutexes, for native FreeBSD ABI. Similarly, there is no sense
in

Do not call FreeBSD-ABI specific code for all ABIs

Use sysentvec hooks to only call umtx_thread_exit/umtx_exec, which handle
robust mutexes, for native FreeBSD ABI. Similarly, there is no sense
in calling sigfastblock_clear() for non-native ABIs.

Requested by: dchagin
Reviewed by: dchagin, markj (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D30987

show more ...

Add sv_onexec_old() sysent hook for exec event

Unlike sv_onexec(), it is called from the old (pre-exec) sysentvec structure.
The old vmspace for the process is still intact during the call.

Reviewe

Add sv_onexec_old() sysent hook for exec event

Unlike sv_onexec(), it is called from the old (pre-exec) sysentvec structure.
The old vmspace for the process is still intact during the call.

Reviewed by: dchagin, markj
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D30987

show more ...

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

show more ...

Add a knob to disable dequeueing SIGCHLD on waiting for live process

It seems that Linux does not dequeue siginfo for SIGCHLD when wait*(2)
reports status of the running process. In particular, sig

Add a knob to disable dequeueing SIGCHLD on waiting for live process

It seems that Linux does not dequeue siginfo for SIGCHLD when wait*(2)
reports status of the running process. In particular, sigwaitinfo(2)
and other signal querying syscalls can observe the siginfo after wait.

FreeBSD dequeued siginfo from the beginning, so we cannot change the
default ABI to be more compatible. Still, add a knob to enable to
change to the other behavior for debugging purposes.

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

show more ...

Add a knob to not drop signal with default ignored or ignored actions

Traditionally, BSD drops signals with the default action during send,
not even putting them to the destination process queue. T

Add a knob to not drop signal with default ignored or ignored actions

Traditionally, BSD drops signals with the default action during send,
not even putting them to the destination process queue. This semantic
is not shared with other operating systems (Linux), which do queue
such signals. In particular, sigtimedwait(2) and related syscalls can
observe the delivery.

Add a global knob kern.sig_discard_ign which can be set to false to force
enqueuing of the signals with default action. Also add an ABI flag to
indicate that signals should be queued.

Note that it is not practical to run with the knob turned on, because almost
all software that care about the delivery of such signals, is aware of the
difference, and misbehaves if the signals are actually queued. The purpose
of the knob as is is to allow for easier diagnostic of the programs that
need the adjustments, to confirm the cause of problem.

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

show more ...