3538a0fbbd
Hou Tao says: ==================== From: Hou Tao <houtao1@huawei.com> Hi, The patchset tries to fix the hard-up problem found when checking how htab handles element reuse in bpf memory allocator. The immediate reuse of freed elements will reinitialize special fields (e.g., bpf_spin_lock) in htab map value and it may corrupt lookup procedure with BFP_F_LOCK flag which acquires bpf-spin-lock during value copying, and lead to hard-lock as shown in patch #2. Patch #1 fixes it by using __GFP_ZERO when allocating the object from slab and the behavior is similar with the preallocated hash-table case. Please see individual patches for more details. And comments are always welcome. Regards, Change Log: v1: * Use __GFP_ZERO instead of ctor to avoid retpoline overhead (from Alexei) * Add comments for check_and_init_map_value() (from Alexei) * split __GFP_ZERO patches out of the original patchset to unblock the development work of others. RFC: https://lore.kernel.org/bpf/20221230041151.1231169-1-houtao@huaweicloud.com ==================== Signed-off-by: Alexei Starovoitov <ast@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.
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.