e1ef78dce9
On ARM64 the stack pointer should be aligned at a 16 byte boundary or
the SPAlignmentFault can occur. The fexit_sleep selftest allocates the
stack for the child process as a character array, this is not guaranteed
to be aligned at 16 bytes.
Because of the SPAlignmentFault, the child process is killed before it
can do the nanosleep call and hence fentry_cnt remains as 0. This causes
the main thread to hang on the following line:
while (READ_ONCE(fexit_skel->bss->fentry_cnt) != 2);
Fix this by allocating the stack using mmap() as described in the
example in the man page of clone().
Remove the fexit_sleep test from the DENYLIST of arm64.
Fixes: eddbe8e65214 ("selftest/bpf: Add a test to check trampoline freeing logic.")
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240715173327.8657-1-puranjay@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.