f8f261f9ad
[ Upstream commit 71052dcf4be70be4077817297dcde7b155e745f2 ] Two per-CPU variables are allocated as pointer to per-CPU memory which then are used as scratch buffers. We could be smart about this and use instead a per-CPU struct which contains the pointers already and then we need to allocate just the scratch buffers. Add a lock to the struct. By doing so we can avoid the get_cpu() statement and gain lockdep coverage (if enabled) to ensure that the lock is always acquired in the right context. On non-preemptible kernels the lock vanishes. It is okay to use raw_cpu_ptr() in order to get a pointer to the struct since it is protected by the spinlock. The diffstat of this is negative and according to size scompress.o: text data bss dec hex filename 1847 160 24 2031 7ef dbg_before.o 1754 232 4 1990 7c6 dbg_after.o 1799 64 24 1887 75f no_dbg-before.o 1703 88 4 1795 703 no_dbg-after.o The overall size increase difference is also negative. The increase in the data section is only four bytes without lockdep. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Stable-dep-of: 744e1885922a ("crypto: scomp - fix req->dst buffer overflow") Signed-off-by: Sasha Levin <sashal@kernel.org>
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.