arm64: Support passing more registers to signals

To support recent extensions to the Arm architecture we may need to
store more or larger registers when sending a signal.

To support this create a l

arm64: Support passing more registers to signals

To support recent extensions to the Arm architecture we may need to
store more or larger registers when sending a signal.

To support this create a list of these extra registers. Userspace that
needs to access a register in the signal handler can then walk the list
to find the correct register struct and read/write its contents.

Reviewed by: kib, markj (earlier version)
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D43302

show more ...

sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remov

sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

show more ...

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Add compat support for struct reg on arm64

The size of the spsr field in struct reg has changed. Mask the bits
that userspace doesn't know about out as they may be invalid.

While here add a comment

Add compat support for struct reg on arm64

The size of the spsr field in struct reg has changed. Mask the bits
that userspace doesn't know about out as they may be invalid.

While here add a comment why we don't need compat support in set_regs.

Sponsored by: Arm Ltd

show more ...

arm64: extend ESR/SPSR registers to 64b

For the Exception Syndrome Register, ESR_ELx, the upper 32b were
previously unused, but now may contain additional exception info as of
Armv8.7 (FEAT_LS64).

arm64: extend ESR/SPSR registers to 64b

For the Exception Syndrome Register, ESR_ELx, the upper 32b were
previously unused, but now may contain additional exception info as of
Armv8.7 (FEAT_LS64).

Extend ESR from u32->u64 in exception handling code to support this. In
addition, also extend Saved Program Status Register SPSR_ELx in the same
way to allow for future extensions.

Reviewed by: andrew
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D38983

show more ...

Reduce an arm64 VFP critical section

In set_fpcontext we only need a critical section around vfp_discard.
The remainder of the code can run without it.

While here add an assert to check the passed

Reduce an arm64 VFP critical section

In set_fpcontext we only need a critical section around vfp_discard.
The remainder of the code can run without it.

While here add an assert to check the passed in thread is the
current thread as the code already this.

Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D38000

show more ...

Always store the arm64 VFP context

If a thread enters a kernel FP context the PCB_FP_STARTED may be
unset when calling get_fpcontext even if the VFP unit has been used
by the current thread.

Reduce

Always store the arm64 VFP context

If a thread enters a kernel FP context the PCB_FP_STARTED may be
unset when calling get_fpcontext even if the VFP unit has been used
by the current thread.

Reduce the use of this flag to just decide when to store the VFP state.

While here add an assert to check the assumption that the passed in
thread is the current thread and remove the unneeded critical section.
The latter is unneeded as the only place we would need it is in
vfp_save_state and this already has a critical section when needed.

Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D37998

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Always read the VFP regs in the arm64 fill_fpregs

The PCB_FP_STARTED is used to indicate that the current VFP context
has been used since either 1. the start of the thread, or 2. exiting
a kernel FP

Always read the VFP regs in the arm64 fill_fpregs

The PCB_FP_STARTED is used to indicate that the current VFP context
has been used since either 1. the start of the thread, or 2. exiting
a kernel FP context.

When case 2 was added to the kernel this could cause incorrect results
to be returned when a thread exits the kernel FP context and fill_fpregs
is called before it has restored the VFP state, e.g. by trappin on a
userspace VFP instruction.

In both of the cases the base save area is still valid so reduce the
use of the PCB_FP_STARTED flag check to help decide if we need to
store the current threads VFP state.

Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D37994

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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

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Introduce the PROC_SIGCODE() macro

Use a getter macro instead of fetching the sigcode address directly
from a sysent of a given process. It assumes that the sigcode is stored
in the shared page, whi

Introduce the PROC_SIGCODE() macro

Use a getter macro instead of fetching the sigcode address directly
from a sysent of a given process. It assumes that the sigcode is stored
in the shared page, which is true in all cases, except for a.out
binaries. This will be later useful when the shared page address
randomization is introduced.
No functional change intended.

Approved by: mw(mentor)
Sponsored by: Stormshield
Obtained from: Semihalf
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D35392

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Rework the arm64 sigtramp code to be a trampoline

To help with switching to a vdso sigtramp switch to passing through the
sigcode function when entering a signal. This ensures the return address
is

Rework the arm64 sigtramp code to be a trampoline

To help with switching to a vdso sigtramp switch to passing through the
sigcode function when entering a signal. This ensures the return address
is within the function.

Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33690

show more ...

aarch64: Add static asssert for context size

Add a static assert for the siginfo{,32}_t, mcontext{,32}_t and
ucontext{,32}_t sizes. These are de-facto ABI options and cannot change
size ever.

Revie

aarch64: Add static asssert for context size

Add a static assert for the siginfo{,32}_t, mcontext{,32}_t and
ucontext{,32}_t sizes. These are de-facto ABI options and cannot change
size ever.

Reviewed by: kib, andrew, jhb
Differential Revision: https://reviews.freebsd.org/D32958

show more ...

Stop single stepping in signal handers on arm64

We should clear the single step flag when entering a signal hander and
set it when returning. This fixes the ptrace__PT_STEP_with_signal test.

While

Stop single stepping in signal handers on arm64

We should clear the single step flag when entering a signal hander and
set it when returning. This fixes the ptrace__PT_STEP_with_signal test.

While here add support for userspace to set the single step bit as on
x86. This can be used by userspace for self tracing.

Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D34170

show more ...

Sort the names of the arm64 debug registers

While here clean up the names for the naming convention of the other
registers in this file.

Reviewed by: kib, mhorne (earlier version)
Sponsored by: The

Sort the names of the arm64 debug registers

While here clean up the names for the naming convention of the other
registers in this file.

Reviewed by: kib, mhorne (earlier version)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D34060

show more ...

Add arm64 pointer authentication support

Pointer authentication allows userspace to add instructions to insert
a Pointer Authentication Code (PAC) into a register based on an address
and modifier an

Add arm64 pointer authentication support

Pointer authentication allows userspace to add instructions to insert
a Pointer Authentication Code (PAC) into a register based on an address
and modifier and check if the PAC is correct. If the check fails it will
either return an invalid address or fault to the kernel.

As many of these instructions are a NOP when disabled and in earlier
revisions of the architecture this can be used, for example, to sign
the return address before pushing it to the stack making Return-oriented
programming (ROP) attack more difficult on hardware that supports them.

The kernel manages five 128 bit signing keys: 2 instruction keys, 2 data
keys, and a generic key. The instructions then use one of these when
signing the registers. Instructions that use the first four store the
PAC in the register being signed, however the instructions that use the
generic key store the PAC in a separate register.

Currently all userspace threads share all the keys within a process
with a new set of userspace keys being generated when executing a new
process. This means a forked child will share its keys with its parent
until it calls an appropriate exec system call.

In the kernel we allow the use of one of the instruction keys, the ia
key. This will be used to sign return addresses in function calls.
Unlike userspace each kernel thread has its own randomly generated.

Thread0 has a static key as does the early code on secondary CPUs.
This should be safe as there is minimal user interaction with these
threads, however we could generate random keys when the Armv8.5
Random number generation instructions are present.

Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31261

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Add a missing space in the arm64 sendsig

Sponsored by: The FreeBSD Foundation

Remove the sigcode base check on arm64

This was added with the shared page support. It is unused as we always
enable the shared page on FreeBSD executables on arm64.

Fix set but not used warnings in arm64 core code

arm64: move signal delivery code to exec_machdep.c

also move ptrace-related helpers to ptrace_machdep.c.

Reviewed by: emaste, imp
Discussed with: jrtc27
Sponsored by: The FreeBSD Foundation
MFC aft

arm64: move signal delivery code to exec_machdep.c

also move ptrace-related helpers to ptrace_machdep.c.

Reviewed by: emaste, imp
Discussed with: jrtc27
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32310

show more ...

arm64: Support passing more registers to signals

To support recent extensions to the Arm architecture we may need to
store more or larger registers when sending a signal.

To support this create a l

arm64: Support passing more registers to signals

To support recent extensions to the Arm architecture we may need to
store more or larger registers when sending a signal.

To support this create a list of these extra registers. Userspace that
needs to access a register in the signal handler can then walk the list
to find the correct register struct and read/write its contents.

Reviewed by: kib, markj (earlier version)
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D43302

show more ...

sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remov

sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

show more ...

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Add compat support for struct reg on arm64

The size of the spsr field in struct reg has changed. Mask the bits
that userspace doesn't know about out as they may be invalid.

While here add a comment

Add compat support for struct reg on arm64

The size of the spsr field in struct reg has changed. Mask the bits
that userspace doesn't know about out as they may be invalid.

While here add a comment why we don't need compat support in set_regs.

Sponsored by: Arm Ltd

show more ...

arm64: extend ESR/SPSR registers to 64b

For the Exception Syndrome Register, ESR_ELx, the upper 32b were
previously unused, but now may contain additional exception info as of
Armv8.7 (FEAT_LS64).

arm64: extend ESR/SPSR registers to 64b

For the Exception Syndrome Register, ESR_ELx, the upper 32b were
previously unused, but now may contain additional exception info as of
Armv8.7 (FEAT_LS64).

Extend ESR from u32->u64 in exception handling code to support this. In
addition, also extend Saved Program Status Register SPSR_ELx in the same
way to allow for future extensions.

Reviewed by: andrew
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D38983

show more ...

Reduce an arm64 VFP critical section

In set_fpcontext we only need a critical section around vfp_discard.
The remainder of the code can run without it.

While here add an assert to check the passed

Reduce an arm64 VFP critical section

In set_fpcontext we only need a critical section around vfp_discard.
The remainder of the code can run without it.

While here add an assert to check the passed in thread is the
current thread as the code already this.

Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D38000

show more ...