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Add three tests for struct_ops using private stack. ./test_progs -t struct_ops_private_stack #336/1 struct_ops_private_stack/private_stack:OK #336/2 struct_ops_private_stack/private_stack_fail:OK #336/3 struct_ops_private_stack/private_stack_recur:OK #336 struct_ops_private_stack:OK The following is a snippet of a struct_ops check_member() implementation: u32 moff = __btf_member_bit_offset(t, member) / 8; switch (moff) { case offsetof(struct bpf_testmod_ops3, test_1): prog->aux->priv_stack_requested = true; prog->aux->recursion_detected = test_1_recursion_detected; fallthrough; default: break; } return 0; The first test is with nested two different callback functions where the first prog has more than 512 byte stack size (including subprogs) with private stack enabled. The second test is a negative test where the second prog has more than 512 byte stack size without private stack enabled. The third test is the same callback function recursing itself. At run time, the jit trampoline recursion check kicks in to prevent the recursion. The recursion_detected() callback function is implemented by the bpf_testmod, the following message in dmesg bpf_testmod: oh no, recursing into test_1, recursion_misses 1 demonstrates the callback function is indeed triggered when recursion miss happens. Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20241112163938.2225528-1-yonghong.song@linux.dev 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 reStructuredText 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.