kvm_vgic_map_resources() is called when a VCPU if first run and it maps all the VGIC MMIO regions. To prevent double-initialization, the VGIC uses the ready variable to keep track of the state of resources and the global KVM mutex to protect against concurrent accesses. After the lock is taken, the variable is checked again in case another VCPU took the lock between the current VCPU reading ready equals false and taking the lock. The double-checked lock pattern is spread across four different functions: in kvm_vcpu_first_run_init(), in kvm_vgic_map_resource() and in vgic_{v2,v3}_map_resources(), which makes it hard to reason about and introduces minor code duplication. Consolidate the checks in kvm_vgic_map_resources(), where the lock is taken. No functional change intended. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201201150157.223625-4-alexandru.elisei@arm.com |
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Documentation | ||
LICENSES | ||
arch | ||
block | ||
certs | ||
crypto | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
README
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.