mainlining shenanigans
Reading the 'prod' MMIO register in order to determine whether or not there is valid data beyond 'cons' for a given queue does not provide sufficient dependency ordering, as the resulting access is address dependent only on 'cons' and can therefore be speculated ahead of time, potentially allowing stale data to be read by the CPU. Use readl() instead of readl_relaxed() when updating the shadow copy of the 'prod' pointer, so that all speculated memory reads from the corresponding queue can occur only from valid slots. Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com> Link: https://lore.kernel.org/r/1601281922-117296-1-git-send-email-wangzhou1@hisilicon.com [will: Use readl() instead of explicit barrier. Update 'cons' side to match.] Signed-off-by: Will Deacon <will@kernel.org> |
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arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
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 |
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.