dbe3061729
kernel profiling remains broken). memmove() was broken using ALTENTRY(). ALTENTRY() is only different from ENTRY() in the profiling case, and its use in that case was sort of backwards. The backwardness magically turned memmove() into memcpy() instead of completely breaking it. Only the high resolution parts of profiling itself were broken. Use ordinary ENTRY() for memmove(). Turn bcopy() into a tail call to memmove() to reduce complications. This gives slightly different pessimizations and profiling lossage. The pessimizations are minimized by not using a frame pointer() for bcopy(). Calls to profiling functions from exception trampolines were not relocated. This caused crashes on the first exception. Fix this using function pointers. Addresses of exception handlers in trampolines were not relocated. This caused unknown offsets in the profiling data. Relocate by abusing setidt_disp as for pmc although this is slower than necessary and requires namespace pollution. pmc seems to be missing some relocations. Stack traces and lots of other things in debuggers need similar relocations. Most user addresses were misclassified as unknown kernel addresses and then ignored. Treat all unknown addresses as user. Now only user addresses in the kernel text range are significantly misclassified (as known kernel addresses). The ibrs functions didn't preserve enough registers. This is the only recent breakage on amd64. Although these functions are written in asm, in the profiling case they call profiling functions which are mostly for the C ABI, so they only have to save call-used registers. They also have to save arg and return registers in some cases and actually save them in all cases to reduce complications. They end up saving all registers except %ecx on i386 and %r10 and %r11 on amd64. Saving these is only needed for 1 caller on each of amd64 and i386. Save them there. This is slightly simpler. Remove saving %ecx in handle_ibrs_exit on i386. Both handle_ibrs_entry and handle_ibrs_exit use %ecx, but only the latter needed to or did save it. But saving it there doesn't work for the profiling case. amd64 has more automatic saving of the most common scratch registers %rax, %rcx and %rdx (its complications for %r10 are from unusual use of %r10 by SYSCALL). Thus profiling of handle_ibrs_exit_rs() was not broken, and I didn't simplify the saving by moving the saving of these registers from it to the caller.
FreeBSD Source:
This is the top level of the FreeBSD source directory. This file
was last revised on:
FreeBSD
FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms. A large community has continually developed it for more than thirty years. Its advanced networking, security, and storage features have made FreeBSD the platform of choice for many of the busiest web sites and most pervasive embedded networking and storage devices.
For copyright information, please see the file COPYRIGHT in this directory. Additional copyright information also exists for some sources in this tree - please see the specific source directories for more information.
The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7), config(8), https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html, and https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html for more information, including setting make(1) variables.
Source Roadmap:
bin System/user commands.
cddl Various commands and libraries under the Common Development
and Distribution License.
contrib Packages contributed by 3rd parties.
crypto Cryptography stuff (see crypto/README).
etc Template files for /etc.
gnu Various commands and libraries under the GNU Public License.
Please see gnu/COPYING* for more information.
include System include files.
kerberos5 Kerberos5 (Heimdal) package.
lib System libraries.
libexec System daemons.
release Release building Makefile & associated tools.
rescue Build system for statically linked /rescue utilities.
sbin System commands.
secure Cryptographic libraries and commands.
share Shared resources.
stand Boot loader sources.
sys Kernel sources.
sys/<arch>/conf Kernel configuration file
tests Regression tests which can be run by Kyua. See tests/README
for additional information.
tools Utilities for regression testing and miscellaneous tasks.
usr.bin User commands.
usr.sbin System administration commands.
For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see:
https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/current-stable.html