In __sanitizer_cov_trace_pc(), previously we write pc before updating pos. However, some early interrupt code could bypass check_kcov_mode() check and invoke __sanitizer_cov_trace_pc(). If such interrupt is raised between writing pc and updating pos, the pc could be overitten by the recursive __sanitizer_cov_trace_pc(). As suggested by Dmitry, we cold update pos before writing pc to avoid such interleaving. Apply the same change to write_comp_data(). Link: https://lkml.kernel.org/r/20220523053531.1572793-1-liu3101@purdue.edu Signed-off-by: Congyu Liu <liu3101@purdue.edu> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.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.
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