On Tue, Oct 26, 2021 at 12:26:22AM +0200, Maciej W. Rozycki wrote:
Fix a division by zero in `vgacon_resize' with a backtrace like: ... linux-vt-vgacon-init-cell-height-fix.diff Index: linux-macro-ide-tty/drivers/video/console/vgacon.c =================================================================== --- linux-macro-ide-tty.orig/drivers/video/console/vgacon.c +++ linux-macro-ide-tty/drivers/video/console/vgacon.c @@ -366,11 +366,17 @@ static void vgacon_init(struct vc_data * struct uni_pagedir *p;
/*
* We cannot be loaded as a module, therefore init is always 1,* but vgacon_init can be called more than once, and init will* not be 1.
* We cannot be loaded as a module, therefore init will be 1* if we are the default console, however if we are a fallback* console, for example if fbcon has failed registration, then* init will be 0, so we need to make sure our boot parameters* have been copied to the console structure for vgacon_resize* ultimately called by vc_resize. Any subsequent calls to* vgacon_init init will have init set to 0 too.*/ c->vc_can_do_color = vga_can_do_color;
c->vc_scan_lines = vga_scan_lines;
c->vc_font.height = c->vc_cell_height = vga_video_font_height;
/* set dimensions manually if init != 0 since vc_resize() will fail */ if (init) {
@@ -379,8 +385,6 @@ static void vgacon_init(struct vc_data * } else vc_resize(c, vga_video_num_columns, vga_video_num_lines);
- c->vc_scan_lines = vga_scan_lines;
- c->vc_font.height = c->vc_cell_height = vga_video_font_height; c->vc_complement_mask = 0x7700; if (vga_512_chars) c->vc_hi_font_mask = 0x0800;
Just to let you know that the above patch fixes the crashes I experienced. Tried in kernel 4.9.287. The git tree is broken in the sense that it doesn't know the tags v4.9.284, v4.9.285, v4.9.286 and v2.4.287.
Wim.