This option was never enabled in GENERIC and does not appear to work
(the cdevsw is stored in a global array but never passed to make_dev
to be associated with a character device).
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D35008
These files no longer depend on the macros required when these checks
were added.
PR: 263102 (exp-run)
Reviewed by: brooks, imp, emaste
Differential Revision: https://reviews.freebsd.org/D34804
All supported compilers (modern versions of GCC and clang) support
this.
PR: 263102 (exp-run)
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D34802
All supported compilers (modern versions of GCC and clang) support
this.
Many places didn't have an #else so would just silently do the wrong
thing. Ancient versions of icc (the original motivation for this) are
no longer a compiler FreeBSD supports.
PR: 263102 (exp-run)
Reviewed by: brooks, imp
Differential Revision: https://reviews.freebsd.org/D34797
These headers #include <sys/cdefs.h> right after checking if it has
already been #included. The nested #include already existed when the
check for _SYS_CDEFS_H_ was added, so the check shouldn't have been
added in the first place.
PR: 263102 (exp-run)
Reported by: brooks
Reviewed by: brooks, imp, emaste
Differential Revision: https://reviews.freebsd.org/D34796
This register set contains the values of the fsbase and gsbase
registers. Note that these registers can already be controlled
individually via ptrace(2) via MD operations, so the main reason for
adding this is to include these register values in core dumps. In
particular, this will enable looking up the value of TLS variables
from core dumps in gdb.
The value of NT_X86_SEGBASES was chosen to match the value of
NT_386_TLS on Linux. The notes serve similar purposes, but FreeBSD
will never dump a note equivalent to NT_386_TLS (which dumps a single
segment descriptor rather than a pair of addresses) and picking a
currently-unused value in the NT_X86_* range could result in a future
conflict.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D34650
Introduce a helper to fetch the TSC frequency from CPUID when running
under Xen.
Since the TSC can also be initialized early when running as a Xen
guest pull out the call to tsc_init() from the
early_clock_source_init() handlers and place it in clock_init(), as
otherwise all handlers would call tsc_init() anyway.
Reviewed by: markj
Sponsored by: Citrix Systems R&D
Differential revision: https://reviews.freebsd.org/D34581
This lets us use the TSC to implement early DELAY, limiting the use of
the sometimes-unreliable 8254 PIT.
PR: 262155
Reviewed by: emaste
Tested by: emaste, mike tancsa <mike@sentex.net>, Stefan Hegnauer <stefan.hegnauer@gmx.ch>
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D34367
In a subsequent commit clock_init() will attempt to determine the TSC
frequency, and this requires that CPU identification is finalized.
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Add a static assert for the siginfo_t, mcontext_t and ucontext_t
sizes. These are de-facto ABI options and cannot change size ever.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D34211
These headers originate with the Xen project and shouldn't be mixed with
the main portion of the FreeBSD kernel. Notably they shouldn't be the
target of clean-up commits.
Switch to use the headers in sys/contrib/xen.
Reviewed by: royger
Modules no longer call kernel functions for atomic ops, and since the
previous commit, we always use lock prefix.
Submitted by: Elliott Mitchell <ehem+freebsd@m5p.com>
Reviewed by: jhb, markj
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D34153
Atomics have significant other use besides providing in-system
primitives for safe memory updates. They are used for implementing
communication with out of system software or hardware following some
protocols.
For instance, even UP kernel might require a protocol using atomics to
communicate with the software-emulated device on SMP hypervisor. Or
real hardware might need atomic accesses as part of the proper
management protocol.
Another point is that UP configurations on x86 are extinct, so slight
performance hit by unconditionally use proper atomics is not important.
It is compensated by less code clutter, which in fact improves the
UP/i386 lifetime expectations.
Requested by: Elliott Mitchell <ehem+freebsd@m5p.com>
Reviewed by: Elliott Mitchell, imp, jhb, markj, royger
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D34153
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
The approach taken by the stack gap implementation was to insert a
random gap between the top of the fixed stack mapping and the true top
of the main process stack. This approach was chosen so as to avoid
randomizing the previously fixed address of certain process metadata
stored at the top of the stack, but had some shortcomings. In
particular, mlockall(2) calls would wire the gap, bloating the process'
memory usage, and RLIMIT_STACK included the size of the gap so small
(< several MB) limits could not be used.
There is little value in storing each process' ps_strings at a fixed
location, as only very old programs hard-code this address; consumers
were converted decades ago to use a sysctl-based interface for this
purpose. Thus, this change re-implements stack address randomization by
simply breaking the convention of storing ps_strings at a fixed
location, and randomizing the location of the entire stack mapping.
This implementation is simpler and avoids the problems mentioned above,
while being unlikely to break compatibility anywhere the default ASLR
settings are used.
The kern.elfN.aslr.stack_gap sysctl is renamed to kern.elfN.aslr.stack,
and is re-enabled by default.
PR: 260303
Reviewed by: kib
Discussed with: emaste, mw
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33704
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
