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RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DKIM_TRACE(0.00)[suse.de:+] X-Spam-Flag: NO Hi Am 23.09.26 um 14:57 schrieb Greg KH: [...] >> + * Returns: >> + * The index of the cursor's first scanline within the character cell >> + */ >> +unsigned int vc_cursor_start(unsigned int cell_height, unsigned int cursor_size) >> +{ >> + const unsigned int cursor_default_size = CUR_SIZE(READ_ONCE(cur_default)); >> + >> +retry: >> + switch (cursor_size) { >> + case CUR_NONE: >> + return cell_height; >> + case CUR_UNDERLINE: >> + if (cell_height < 10) >> + return cell_height - 1; >> + else >> + return cell_height - 3; >> + case CUR_LOWER_THIRD: >> + return cell_height - cell_height / 3; >> + case CUR_LOWER_HALF: >> + return cell_height - cell_height / 2; >> + case CUR_TWO_THIRDS: >> + return cell_height - (cell_height * 2) / 3; >> + case CUR_BLOCK: >> + return 0; >> + default: >> + pr_warn_once("Unknown cursor %u\n", cursor_size); > Can userspace trigger this? If not, who can? Yes. There's the "vt.cur_default" parameter on the kernel's command line [1], and apparently there's some escape sequence. [2]  The cursor size is the lowest 4 bits of that value, while [1] https://elixir.bootlin.com/linux/v7.2.6/source/drivers/tty/vt/vt.c#L167 [2] https://elixir.bootlin.com/linux/v7.2.6/source/drivers/tty/vt/vt.c#L2523 Apart from that, I just noticed that this switch should certainly handle CUR_DEF without printing a warning. > >> + if (cursor_size != cursor_default_size) >> + cursor_size = cursor_default_size; >> + else >> + cursor_size = CUR_UNDERLINE; > Why underline as a default? This has been the default all along. It is the default value of the cur_default parameter and picked up by vt when starting up a console. [3] VGA BIOSes tend to default to underline as well AFAICT. Only the old cursor code in fbcon falls back to full-size blocks if nothing else works. Using underline harmonizes behavior across components. [3] https://elixir.bootlin.com/linux/v7.2.6/source/drivers/tty/vt/vt.c#L2297 Best regards Thomas > > thanks, > > greg k-h -- -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com GF: Stefan Gaiser, Jochen Jaser, Abhinav Puri, (HRB 36809, AG Nürnberg)