The explanation from https://reviews.freebsd.org/D39637 by stevek: The "use_xsave" variable is a global and that is only supposed to be initialized early before scheduling gets started. However, with the way the ifuncs for "fpusave" and "fpurestore" are implemented, the value could be changed at runtime when scheduling is active if "use_xsave" was set to 0 by the tunable. This leaves a window of opportunity where "use_xsave" gets re-initialized to 1 and a context switch could occur with a thread that was not set up to be able to use xsave functionality. This can lead to an "privileged instruction fault". The fix is to protect "use_xsave" from being initialized more than once. Reported and reviewed by: stevek Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D39660 |
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.. | ||
amd64 | ||
arm | ||
arm64 | ||
bsm | ||
cam | ||
cddl | ||
compat | ||
conf | ||
contrib | ||
crypto | ||
ddb | ||
dev | ||
dts | ||
fs | ||
gdb | ||
geom | ||
gnu | ||
i386 | ||
isa | ||
kern | ||
kgssapi | ||
libkern | ||
modules | ||
net | ||
net80211 | ||
netgraph | ||
netinet | ||
netinet6 | ||
netipsec | ||
netlink | ||
netpfil | ||
netsmb | ||
nfs | ||
nfsclient | ||
nfsserver | ||
nlm | ||
ofed | ||
opencrypto | ||
powerpc | ||
riscv | ||
rpc | ||
security | ||
sys | ||
teken | ||
tests | ||
tools | ||
ufs | ||
vm | ||
x86 | ||
xdr | ||
xen | ||
Makefile | ||
README.md |
FreeBSD Kernel Source:
This directory contains the source files and build glue that make up the FreeBSD kernel and its modules, including both original and contributed software.
Kernel configuration files are located in the conf/
subdirectory of each
architecture. GENERIC
is the configuration used in release builds. NOTES
contains documentation of all possible entries. LINT
is a compile-only
configuration used to maximize build coverage and detect regressions.
Source Roadmap:
Directory | Description |
---|---|
amd64 | AMD64 (64-bit x86) architecture support |
arm | 32-bit ARM architecture support |
arm64 | 64-bit ARM (AArch64) architecture support |
cam | Common Access Method storage subsystem - cam(4) and ctl(4) |
cddl | CDDL-licensed optional sources such as DTrace |
conf | kernel build glue |
compat | Linux compatibility layer, FreeBSD 32-bit compatibility |
contrib | 3rd-party imported software such as OpenZFS |
crypto | crypto drivers |
ddb | interactive kernel debugger - ddb(4) |
fs | most filesystems, excluding UFS, NFS, and ZFS |
dev | device drivers and other arch independent code |
gdb | kernel remote GDB stub - gdb(4) |
geom | GEOM framework - geom(4) |
i386 | i386 (32-bit x86) architecture support |
kern | main part of the kernel |
libkern | libc-like and other support functions for kernel use |
modules | kernel module infrastructure |
net | core networking code |
net80211 | wireless networking (IEEE 802.11) - net80211(4) |
netgraph | graph-based networking subsystem - netgraph(4) |
netinet | IPv4 protocol implementation - inet(4) |
netinet6 | IPv6 protocol implementation - inet6(4) |
netipsec | IPsec protocol implementation - ipsec(4) |
netpfil | packet filters - ipfw(4) , pf(4) , and ipfilter(4) |
opencrypto | OpenCrypto framework - crypto(7) |
powerpc | PowerPC/POWER (32 and 64-bit) architecture support |
riscv | 64-bit RISC-V architecture support |
security | security facilities - audit(4) and mac(4) |
sys | kernel headers |
tests | kernel unit tests |
ufs | Unix File System - ffs(7) |
vm | virtual memory system |
x86 | code shared by AMD64 and i386 architectures |