Hi Am 08.02.22 um 22:08 schrieb Daniel Vetter:
There's two minor behaviour changes in here: - in error paths we now consistently call fb_ops->fb_release - fb_release really can't fail (fbmem.c ignores it too) and there's no reasonable cleanup we can do anyway. Note that everything in fbcon.c is protected by the big console_lock() lock (especially all the global variables), so the minor changes in ordering of setup/cleanup do not matter. v2: Explain a bit better why this is all correct (Sam) Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: Claudio Suarez <cssk@xxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Cc: Du Cheng <ducheng2@xxxxxxxxx> --- drivers/video/fbdev/core/fbcon.c | 107 +++++++++++++++---------------- 1 file changed, 53 insertions(+), 54 deletions(-) diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index 058e885d24f6..3e1a3e7bf527 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -682,19 +682,37 @@ static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount)#endif /* CONFIG_MISC_TILEBLITTING */ +static int fbcon_open(struct fb_info *info)+{ + if (!try_module_get(info->fbops->owner)) + return -ENODEV; + + if (info->fbops->fb_open && + info->fbops->fb_open(info, 0)) { + module_put(info->fbops->owner); + return -ENODEV; + } + + return 0; +} + +static void fbcon_release(struct fb_info *info) +{ + if (info->fbops->fb_release) + info->fbops->fb_release(info, 0); + + module_put(info->fbops->owner); +}static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info,int unit, int oldidx) { struct fbcon_ops *ops = NULL; - int err = 0; - - if (!try_module_get(info->fbops->owner)) - err = -ENODEV; + int err;- if (!err && info->fbops->fb_open &&- info->fbops->fb_open(info, 0)) - err = -ENODEV; + err = fbcon_open(info); + if (err) + return err;if (!err) {ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); @@ -715,7 +733,7 @@ static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info,if (err) {con2fb_map[unit] = oldidx; - module_put(info->fbops->owner); + fbcon_release(info); }return err;@@ -726,45 +744,34 @@ static int con2fb_release_oldinfo(struct vc_data *vc, struct fb_info *oldinfo, int oldidx, int found) { struct fbcon_ops *ops = oldinfo->fbcon_par; - int err = 0, ret; + int ret;- if (oldinfo->fbops->fb_release &&- oldinfo->fbops->fb_release(oldinfo, 0)) { - con2fb_map[unit] = oldidx;
We don't need oldidx any longer?There's some logic wrt to the parameter 'found' here and in set_con2fb_map() that appears to be relevant.
Best regards Thomas
- if (!found && newinfo->fbops->fb_release) - newinfo->fbops->fb_release(newinfo, 0); - if (!found) - module_put(newinfo->fbops->owner); - err = -ENODEV; - } + fbcon_release(oldinfo);- if (!err) {- fbcon_del_cursor_work(oldinfo); - kfree(ops->cursor_state.mask); - kfree(ops->cursor_data); - kfree(ops->cursor_src); - kfree(ops->fontbuffer); - kfree(oldinfo->fbcon_par); - oldinfo->fbcon_par = NULL; - module_put(oldinfo->fbops->owner); - /* - If oldinfo and newinfo are driving the same hardware, - the fb_release() method of oldinfo may attempt to - restore the hardware state. This will leave the - newinfo in an undefined state. Thus, a call to - fb_set_par() may be needed for the newinfo. - */ - if (newinfo && newinfo->fbops->fb_set_par) { - ret = newinfo->fbops->fb_set_par(newinfo); + fbcon_del_cursor_work(oldinfo); + kfree(ops->cursor_state.mask); + kfree(ops->cursor_data); + kfree(ops->cursor_src); + kfree(ops->fontbuffer); + kfree(oldinfo->fbcon_par); + oldinfo->fbcon_par = NULL; + /* + If oldinfo and newinfo are driving the same hardware, + the fb_release() method of oldinfo may attempt to + restore the hardware state. This will leave the + newinfo in an undefined state. Thus, a call to + fb_set_par() may be needed for the newinfo. + */ + if (newinfo && newinfo->fbops->fb_set_par) { + ret = newinfo->fbops->fb_set_par(newinfo);- if (ret)- printk(KERN_ERR "con2fb_release_oldinfo: " - "detected unhandled fb_set_par error, " - "error code %d\n", ret); - } + if (ret) + printk(KERN_ERR "con2fb_release_oldinfo: " + "detected unhandled fb_set_par error, " + "error code %d\n", ret); }- return err;+ return 0; }static void con2fb_init_display(struct vc_data *vc, struct fb_info *info,@@ -919,7 +926,6 @@ static const char *fbcon_startup(void) struct fbcon_display *p = &fb_display[fg_console]; struct vc_data *vc = vc_cons[fg_console].d; const struct font_desc *font = NULL; - struct module *owner; struct fb_info *info = NULL; struct fbcon_ops *ops; int rows, cols; @@ -938,17 +944,12 @@ static const char *fbcon_startup(void) if (!info) return NULL; - owner = info->fbops->owner; - if (!try_module_get(owner)) + if (fbcon_open(info)) return NULL; - if (info->fbops->fb_open && info->fbops->fb_open(info, 0)) { - module_put(owner); - return NULL; - }ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);if (!ops) { - module_put(owner); + fbcon_release(info); return NULL; }@@ -3314,10 +3315,6 @@ static void fbcon_exit(void)}if (mapped) {- if (info->fbops->fb_release) - info->fbops->fb_release(info, 0); - module_put(info->fbops->owner); - if (info->fbcon_par) { struct fbcon_ops *ops = info->fbcon_par;@@ -3327,6 +3324,8 @@ static void fbcon_exit(void)kfree(info->fbcon_par); info->fbcon_par = NULL; } + + fbcon_release(info); } } }
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Ivo Totev
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