gcc complains about undefined behavior in calling snprintf() with the same buffer as input and output: drivers/net/wireless/ti/wl18xx/debugfs.c: In function 'diversity_num_of_packets_per_ant_read': drivers/net/wireless/ti/wl18xx/../wlcore/debugfs.h:86:3: error: 'snprintf' argument 4 overlaps destination object 'buf' [-Werror=restrict] 86 | snprintf(buf, sizeof(buf), "%s[%d] = %d\n", \ | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 87 | buf, i, stats->sub.name[i]); \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/wireless/ti/wl18xx/debugfs.c:24:2: note: in expansion of macro 'DEBUGFS_FWSTATS_FILE_ARRAY' 24 | DEBUGFS_FWSTATS_FILE_ARRAY(a, b, c, wl18xx_acx_statistics) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/wireless/ti/wl18xx/debugfs.c:159:1: note: in expansion of macro 'WL18XX_DEBUGFS_FWSTATS_FILE_ARRAY' 159 | WL18XX_DEBUGFS_FWSTATS_FILE_ARRAY(diversity, num_of_packets_per_ant, There are probably other ways of handling the debugfs file, without using on-stack buffers, but a simple workaround here is to remember the current position in the buffer and just keep printing in there. Fixes: bcca1bbdd412 ("wlcore: add debugfs macro to help print fw statistics arrays") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Link: https://lore.kernel.org/r/20210323125723.1961432-1-arnd@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.
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