If trace_seq becomes full, trace_seq_vprintf() no longer consumes arguments from va_list, making va_list out of sync with format processing by trace_check_vprintf(). This causes va_arg() in trace_check_vprintf() to return wrong positional argument, which results into a WARN_ON_ONCE() hit. ftrace_stress_test from LTP triggers this situation. Fix it by explicitly avoiding further use if va_list at the point when it's consistency can no longer be guaranteed. Link: https://lkml.kernel.org/r/20211118145516.13219-1-nikita.yushchenko@virtuozzo.com Signed-off-by: Nikita Yushchenko <nikita.yushchenko@virtuozzo.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.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.
Description
Languages
C
97.6%
Assembly
1%
Shell
0.5%
Python
0.3%
Makefile
0.3%