| Message ID | 20220131210552.482606-14-daniel.vetter@ffwll.ch |
|---|---|
| State | Superseded |
| Headers | show |
| Series | some fbcon patches, mostly locking | expand |
On Mon, Jan 31, 2022 at 10:05:44PM +0100, Daniel Vetter wrote: > No idea why con2fb_acquire_newinfo() initializes much less than > fbcon_startup(), but so be it. From a quick look most of the > un-initialized stuff should be fairly harmless, but who knows. > > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> > Cc: Daniel Vetter <daniel@ffwll.ch> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> > Cc: Thomas Zimmermann <tzimmermann@suse.de> > Cc: Claudio Suarez <cssk@net-c.es> > Cc: Du Cheng <ducheng2@gmail.com> > --- > drivers/video/fbdev/core/fbcon.c | 74 +++++++++++++------------------- > 1 file changed, 31 insertions(+), 43 deletions(-) > > diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c > index b83a5a77d8a8..5a3391ff038d 100644 > --- a/drivers/video/fbdev/core/fbcon.c > +++ b/drivers/video/fbdev/core/fbcon.c > @@ -680,8 +680,18 @@ static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount) > > #endif /* CONFIG_MISC_TILEBLITTING */ > > +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 fbcon_open(struct fb_info *info) > { > + struct fbcon_ops *ops; > + > if (!try_module_get(info->fbops->owner)) > return -ENODEV; > > @@ -691,19 +701,22 @@ static int fbcon_open(struct fb_info *info) > return -ENODEV; > } > > - return 0; > -} > + ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); > + if (!ops) { > + fbcon_release(info); > + return -ENOMEM; > + } > > -static void fbcon_release(struct fb_info *info) > -{ > - if (info->fbops->fb_release) > - info->fbops->fb_release(info, 0); > + INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor); > + ops->info = info; > + info->fbcon_par = ops; > + ops->cur_blink_jiffies = HZ / 5; > > - module_put(info->fbops->owner); > + return 0; > } > > static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, > - int unit, int oldidx) > + int unit) > { > struct fbcon_ops *ops = NULL; > int err; > @@ -712,27 +725,10 @@ static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, > if (err) > return err; > > - if (!err) { > - ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); > - if (!ops) > - err = -ENOMEM; > - > - INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor); > - } > - > - if (!err) { > - ops->cur_blink_jiffies = HZ / 5; > - ops->info = info; > - info->fbcon_par = ops; > - > - if (vc) > - set_blitting_type(vc, info); > - } > + ops = info->fbcon_par; > > - if (err) { > - con2fb_map[unit] = oldidx; > - fbcon_release(info); > - } > + if (vc) > + set_blitting_type(vc, info); > > return err; > } > @@ -840,9 +836,11 @@ static int set_con2fb_map(int unit, int newidx, int user) > > found = search_fb_in_map(newidx); > > - con2fb_map[unit] = newidx; > - if (!err && !found) > - err = con2fb_acquire_newinfo(vc, info, unit, oldidx); > + if (!err && !found) { > + err = con2fb_acquire_newinfo(vc, info, unit); > + if (!err) > + con2fb_map[unit] = newidx; > + } This looks like an unintentional change of functionality as con2fb_map[unit] is only assigned when we do a con2fb_acquire_newinfo(). Staring at the code I could not say it is wrong, but not nice to hide the change in this patch. Sam > > /* > * If old fb is not mapped to any of the consoles, > @@ -939,20 +937,10 @@ static const char *fbcon_startup(void) > if (fbcon_open(info)) > return NULL; > > - ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); > - if (!ops) { > - fbcon_release(info); > - return NULL; > - } > - > - INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor); > - > + ops = info->fbcon_par; > ops->currcon = -1; > ops->graphics = 1; > ops->cur_rotate = -1; > - ops->cur_blink_jiffies = HZ / 5; > - ops->info = info; > - info->fbcon_par = ops; > > p->con_rotate = initial_rotation; > if (p->con_rotate == -1) > @@ -1022,7 +1010,7 @@ static void fbcon_init(struct vc_data *vc, int init) > return; > > if (!info->fbcon_par) > - con2fb_acquire_newinfo(vc, info, vc->vc_num, -1); > + con2fb_acquire_newinfo(vc, info, vc->vc_num); > > /* If we are not the first console on this > fb, copy the font from that console */ > -- > 2.33.0
On Tue, Feb 08, 2022 at 02:53:59PM +0100, Daniel Vetter wrote: > On Fri, Feb 04, 2022 at 08:35:31PM +0100, Sam Ravnborg wrote: > > On Mon, Jan 31, 2022 at 10:05:44PM +0100, Daniel Vetter wrote: > > > No idea why con2fb_acquire_newinfo() initializes much less than > > > fbcon_startup(), but so be it. From a quick look most of the > > > un-initialized stuff should be fairly harmless, but who knows. > > > > > > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> > > > Cc: Daniel Vetter <daniel@ffwll.ch> > > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > > Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> > > > Cc: Thomas Zimmermann <tzimmermann@suse.de> > > > Cc: Claudio Suarez <cssk@net-c.es> > > > Cc: Du Cheng <ducheng2@gmail.com> > > > --- > > > drivers/video/fbdev/core/fbcon.c | 74 +++++++++++++------------------- > > > 1 file changed, 31 insertions(+), 43 deletions(-) > > > > > > diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c > > > index b83a5a77d8a8..5a3391ff038d 100644 > > > --- a/drivers/video/fbdev/core/fbcon.c > > > +++ b/drivers/video/fbdev/core/fbcon.c > > > @@ -680,8 +680,18 @@ static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount) > > > > > > #endif /* CONFIG_MISC_TILEBLITTING */ > > > > > > +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 fbcon_open(struct fb_info *info) > > > { > > > + struct fbcon_ops *ops; > > > + > > > if (!try_module_get(info->fbops->owner)) > > > return -ENODEV; > > > > > > @@ -691,19 +701,22 @@ static int fbcon_open(struct fb_info *info) > > > return -ENODEV; > > > } > > > > > > - return 0; > > > -} > > > + ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); > > > + if (!ops) { > > > + fbcon_release(info); > > > + return -ENOMEM; > > > + } > > > > > > -static void fbcon_release(struct fb_info *info) > > > -{ > > > - if (info->fbops->fb_release) > > > - info->fbops->fb_release(info, 0); > > > + INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor); > > > + ops->info = info; > > > + info->fbcon_par = ops; > > > + ops->cur_blink_jiffies = HZ / 5; > > > > > > - module_put(info->fbops->owner); > > > + return 0; > > > } > > > > > > static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, > > > - int unit, int oldidx) > > > + int unit) > > > { > > > struct fbcon_ops *ops = NULL; > > > int err; > > > @@ -712,27 +725,10 @@ static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, > > > if (err) > > > return err; > > > > > > - if (!err) { > > > - ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); > > > - if (!ops) > > > - err = -ENOMEM; > > > - > > > - INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor); > > > - } > > > - > > > - if (!err) { > > > - ops->cur_blink_jiffies = HZ / 5; > > > - ops->info = info; > > > - info->fbcon_par = ops; > > > - > > > - if (vc) > > > - set_blitting_type(vc, info); > > > - } > > > + ops = info->fbcon_par; > > > > > > - if (err) { > > > - con2fb_map[unit] = oldidx; > > > - fbcon_release(info); > > > - } > > > + if (vc) > > > + set_blitting_type(vc, info); > > > > > > return err; > > > } > > > @@ -840,9 +836,11 @@ static int set_con2fb_map(int unit, int newidx, int user) > > > > > > found = search_fb_in_map(newidx); > > > > > > - con2fb_map[unit] = newidx; > > > - if (!err && !found) > > > - err = con2fb_acquire_newinfo(vc, info, unit, oldidx); > > > + if (!err && !found) { > > > + err = con2fb_acquire_newinfo(vc, info, unit); > > > + if (!err) > > > + con2fb_map[unit] = newidx; > > > + } > > This looks like an unintentional change of functionality as con2fb_map[unit] is > > only assigned when we do a con2fb_acquire_newinfo(). > > > > Staring at the code I could not say it is wrong, but not nice to hide > > the change in this patch. > > Nope, it's not an unintentional bugfix. The old con2fb_acquire_newinfo did > reset con2fb_map to oldidx upon failure, which I've found to be a most > bizarre calling convention. So this sorts this out. > > The reason I smashed this into the same patch is that I had to remove the > fbcon_release call, and so the error handling in there looked even more > funny. But I indeed failed to explain this all in the commit message. > > Ack with that explainer, or do you want me to split this out properly? Please update the commit message, then this patch has my: Acked-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index b83a5a77d8a8..5a3391ff038d 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -680,8 +680,18 @@ static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount) #endif /* CONFIG_MISC_TILEBLITTING */ +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 fbcon_open(struct fb_info *info) { + struct fbcon_ops *ops; + if (!try_module_get(info->fbops->owner)) return -ENODEV; @@ -691,19 +701,22 @@ static int fbcon_open(struct fb_info *info) return -ENODEV; } - return 0; -} + ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); + if (!ops) { + fbcon_release(info); + return -ENOMEM; + } -static void fbcon_release(struct fb_info *info) -{ - if (info->fbops->fb_release) - info->fbops->fb_release(info, 0); + INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor); + ops->info = info; + info->fbcon_par = ops; + ops->cur_blink_jiffies = HZ / 5; - module_put(info->fbops->owner); + return 0; } static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, - int unit, int oldidx) + int unit) { struct fbcon_ops *ops = NULL; int err; @@ -712,27 +725,10 @@ static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, if (err) return err; - if (!err) { - ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); - if (!ops) - err = -ENOMEM; - - INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor); - } - - if (!err) { - ops->cur_blink_jiffies = HZ / 5; - ops->info = info; - info->fbcon_par = ops; - - if (vc) - set_blitting_type(vc, info); - } + ops = info->fbcon_par; - if (err) { - con2fb_map[unit] = oldidx; - fbcon_release(info); - } + if (vc) + set_blitting_type(vc, info); return err; } @@ -840,9 +836,11 @@ static int set_con2fb_map(int unit, int newidx, int user) found = search_fb_in_map(newidx); - con2fb_map[unit] = newidx; - if (!err && !found) - err = con2fb_acquire_newinfo(vc, info, unit, oldidx); + if (!err && !found) { + err = con2fb_acquire_newinfo(vc, info, unit); + if (!err) + con2fb_map[unit] = newidx; + } /* * If old fb is not mapped to any of the consoles, @@ -939,20 +937,10 @@ static const char *fbcon_startup(void) if (fbcon_open(info)) return NULL; - ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); - if (!ops) { - fbcon_release(info); - return NULL; - } - - INIT_DELAYED_WORK(&ops->cursor_work, fb_flashcursor); - + ops = info->fbcon_par; ops->currcon = -1; ops->graphics = 1; ops->cur_rotate = -1; - ops->cur_blink_jiffies = HZ / 5; - ops->info = info; - info->fbcon_par = ops; p->con_rotate = initial_rotation; if (p->con_rotate == -1) @@ -1022,7 +1010,7 @@ static void fbcon_init(struct vc_data *vc, int init) return; if (!info->fbcon_par) - con2fb_acquire_newinfo(vc, info, vc->vc_num, -1); + con2fb_acquire_newinfo(vc, info, vc->vc_num); /* If we are not the first console on this fb, copy the font from that console */
No idea why con2fb_acquire_newinfo() initializes much less than fbcon_startup(), but so be it. From a quick look most of the un-initialized stuff should be fairly harmless, but who knows. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Claudio Suarez <cssk@net-c.es> Cc: Du Cheng <ducheng2@gmail.com> --- drivers/video/fbdev/core/fbcon.c | 74 +++++++++++++------------------- 1 file changed, 31 insertions(+), 43 deletions(-)