v3: modify git message.
v2: add patch d48de54a9dab ("printk: Export is_console_locked") to fix a build error caused by v1 if CONFIG_FB = m. ERROR: "is_console_locked" [drivers/video/fbdev/core/fb.ko] undefined!
v1: https://lore.kernel.org/stable/20220729031140.21806-1-chenjun102@huawei.com/
Hans de Goede (1): printk: Export is_console_locked
Helge Deller (2): fbcon: Prevent that screen size is smaller than font size fbmem: Check virtual screen sizes in fb_set_var()
drivers/video/fbdev/core/fbcon.c | 28 ++++++++++++++++++++++++++++ drivers/video/fbdev/core/fbmem.c | 20 +++++++++++++++++--- include/linux/fbcon.h | 4 ++++ kernel/printk/printk.c | 1 + 4 files changed, 50 insertions(+), 3 deletions(-)
From: Hans de Goede hdegoede@redhat.com
commit d48de54a9dab5370edd2e991f78cc7996cf5483e upstream
This is a preparation patch for adding a number of WARN_CONSOLE_UNLOCKED() calls to the fbcon code, which may be built as a module (event though usually it is not).
Acked-by: Steven Rostedt (VMware) rostedt@goodmis.org Acked-by: Sergey Senozhatsky sergey.senozhatsky@gmail.com Acked-by: Petr Mladek pmladek@suse.com Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com Signed-off-by: Chen Jun chenjun102@huawei.com --- kernel/printk/printk.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 11173d0b51bc..ad4772869d48 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2259,6 +2259,7 @@ int is_console_locked(void) { return console_locked; } +EXPORT_SYMBOL(is_console_locked);
/* * Check if we have any console that is capable of printing while cpu is
From: Helge Deller deller@gmx.de
commit e64242caef18b4a5840b0e7a9bff37abd4f4f933 upstream
We need to prevent that users configure a screen size which is smaller than the currently selected font size. Otherwise rendering chars on the screen will access memory outside the graphics memory region.
This patch adds a new function fbcon_modechange_possible() which implements this check and which later may be extended with other checks if necessary. The new function is called from the FBIOPUT_VSCREENINFO ioctl handler in fbmem.c, which will return -EINVAL if userspace asked for a too small screen size.
Signed-off-by: Helge Deller deller@gmx.de Reviewed-by: Geert Uytterhoeven geert@linux-m68k.org [Chen Jun: adjust context] Signed-off-by: Chen Jun chenjun102@huawei.com --- drivers/video/fbdev/core/fbcon.c | 28 ++++++++++++++++++++++++++++ drivers/video/fbdev/core/fbmem.c | 10 +++++++--- include/linux/fbcon.h | 4 ++++ 3 files changed, 39 insertions(+), 3 deletions(-)
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index a97e94b1c84f..b84264e98929 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -2706,6 +2706,34 @@ static void fbcon_set_all_vcs(struct fb_info *info) fbcon_modechanged(info); }
+/* let fbcon check if it supports a new screen resolution */ +int fbcon_modechange_possible(struct fb_info *info, struct fb_var_screeninfo *var) +{ + struct fbcon_ops *ops = info->fbcon_par; + struct vc_data *vc; + unsigned int i; + + WARN_CONSOLE_UNLOCKED(); + + if (!ops) + return 0; + + /* prevent setting a screen size which is smaller than font size */ + for (i = first_fb_vc; i <= last_fb_vc; i++) { + vc = vc_cons[i].d; + if (!vc || vc->vc_mode != KD_TEXT || + registered_fb[con2fb_map[i]] != info) + continue; + + if (vc->vc_font.width > FBCON_SWAP(var->rotate, var->xres, var->yres) || + vc->vc_font.height > FBCON_SWAP(var->rotate, var->yres, var->xres)) + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL_GPL(fbcon_modechange_possible); + static int fbcon_mode_deleted(struct fb_info *info, struct fb_videomode *mode) { diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 9087d467cc46..264e8ca5efa7 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1134,9 +1134,13 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, console_unlock(); return -ENODEV; } - info->flags |= FBINFO_MISC_USEREVENT; - ret = fb_set_var(info, &var); - info->flags &= ~FBINFO_MISC_USEREVENT; + ret = fbcon_modechange_possible(info, &var); + if (!ret) { + info->flags |= FBINFO_MISC_USEREVENT; + ret = fb_set_var(info, &var); + info->flags &= ~FBINFO_MISC_USEREVENT; + } + lock_fb_info(info); unlock_fb_info(info); console_unlock(); if (!ret && copy_to_user(argp, &var, sizeof(var))) diff --git a/include/linux/fbcon.h b/include/linux/fbcon.h index f68a7db14165..39939d55c834 100644 --- a/include/linux/fbcon.h +++ b/include/linux/fbcon.h @@ -4,9 +4,13 @@ #ifdef CONFIG_FRAMEBUFFER_CONSOLE void __init fb_console_init(void); void __exit fb_console_exit(void); +int fbcon_modechange_possible(struct fb_info *info, + struct fb_var_screeninfo *var); #else static inline void fb_console_init(void) {} static inline void fb_console_exit(void) {} +static inline int fbcon_modechange_possible(struct fb_info *info, + struct fb_var_screeninfo *var) { return 0; } #endif
#endif /* _LINUX_FBCON_H */
On Thu, 2022-08-04 at 12:27 +0000, Chen Jun wrote:
From: Helge Deller deller@gmx.de
commit e64242caef18b4a5840b0e7a9bff37abd4f4f933 upstream
We need to prevent that users configure a screen size which is smaller than the currently selected font size. Otherwise rendering chars on the screen will access memory outside the graphics memory region.
This patch adds a new function fbcon_modechange_possible() which implements this check and which later may be extended with other checks if necessary. The new function is called from the FBIOPUT_VSCREENINFO ioctl handler in fbmem.c, which will return -EINVAL if userspace asked for a too small screen size.
Signed-off-by: Helge Deller deller@gmx.de Reviewed-by: Geert Uytterhoeven geert@linux-m68k.org [Chen Jun: adjust context] Signed-off-by: Chen Jun chenjun102@huawei.com
drivers/video/fbdev/core/fbcon.c | 28 ++++++++++++++++++++++++++++ drivers/video/fbdev/core/fbmem.c | 10 +++++++--- include/linux/fbcon.h | 4 ++++ 3 files changed, 39 insertions(+), 3 deletions(-)
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index a97e94b1c84f..b84264e98929 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -2706,6 +2706,34 @@ static void fbcon_set_all_vcs(struct fb_info *info) fbcon_modechanged(info); } +/* let fbcon check if it supports a new screen resolution */ +int fbcon_modechange_possible(struct fb_info *info, struct fb_var_screeninfo *var) +{
- struct fbcon_ops *ops = info->fbcon_par;
- struct vc_data *vc;
- unsigned int i;
- WARN_CONSOLE_UNLOCKED();
- if (!ops)
return 0;- /* prevent setting a screen size which is smaller than font size */
- for (i = first_fb_vc; i <= last_fb_vc; i++) {
vc = vc_cons[i].d;if (!vc || vc->vc_mode != KD_TEXT ||registered_fb[con2fb_map[i]] != info)continue;if (vc->vc_font.width > FBCON_SWAP(var->rotate, var->xres, var->yres) ||vc->vc_font.height > FBCON_SWAP(var->rotate, var->yres, var->xres))return -EINVAL;- }
- return 0;
+} +EXPORT_SYMBOL_GPL(fbcon_modechange_possible);
static int fbcon_mode_deleted(struct fb_info *info, struct fb_videomode *mode) { diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 9087d467cc46..264e8ca5efa7 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1134,9 +1134,13 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, console_unlock(); return -ENODEV; }
info->flags |= FBINFO_MISC_USEREVENT;ret = fb_set_var(info, &var);info->flags &= ~FBINFO_MISC_USEREVENT;
ret = fbcon_modechange_possible(info, &var);if (!ret) {info->flags |= FBINFO_MISC_USEREVENT;ret = fb_set_var(info, &var);info->flags &= ~FBINFO_MISC_USEREVENT;}lock_fb_info(info);
Why do we lock and unlock here consecutively?
Can it be a leftover?
Because in upstream commit, lock encapsulates `fb_set_var`, `fbcon_modechange_possible` and `fbcon_update_vcs` calls, which makes sense.
Here, it doesn't.
console_unlock(); if (!ret && copy_to_user(argp, &var, sizeof(var)))diff --git a/include/linux/fbcon.h b/include/linux/fbcon.h index f68a7db14165..39939d55c834 100644 --- a/include/linux/fbcon.h +++ b/include/linux/fbcon.h @@ -4,9 +4,13 @@ #ifdef CONFIG_FRAMEBUFFER_CONSOLE void __init fb_console_init(void); void __exit fb_console_exit(void); +int fbcon_modechange_possible(struct fb_info *info,
struct fb_var_screeninfo *var);#else static inline void fb_console_init(void) {} static inline void fb_console_exit(void) {} +static inline int fbcon_modechange_possible(struct fb_info *info,
struct fb_var_screeninfo *var) { return 0; }#endif #endif /* _LINUX_FBCON_H */
在 2022/8/5 14:09, Cengiz Can 写道:
On Thu, 2022-08-04 at 12:27 +0000, Chen Jun wrote:
From: Helge Deller deller@gmx.de
commit e64242caef18b4a5840b0e7a9bff37abd4f4f933 upstream
We need to prevent that users configure a screen size which is smaller than the currently selected font size. Otherwise rendering chars on the screen will access memory outside the graphics memory region.
This patch adds a new function fbcon_modechange_possible() which implements this check and which later may be extended with other checks if necessary. The new function is called from the FBIOPUT_VSCREENINFO ioctl handler in fbmem.c, which will return -EINVAL if userspace asked for a too small screen size.
Signed-off-by: Helge Deller deller@gmx.de Reviewed-by: Geert Uytterhoeven geert@linux-m68k.org [Chen Jun: adjust context] Signed-off-by: Chen Jun chenjun102@huawei.com
drivers/video/fbdev/core/fbcon.c | 28 ++++++++++++++++++++++++++++ drivers/video/fbdev/core/fbmem.c | 10 +++++++--- include/linux/fbcon.h | 4 ++++ 3 files changed, 39 insertions(+), 3 deletions(-)
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index a97e94b1c84f..b84264e98929 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -2706,6 +2706,34 @@ static void fbcon_set_all_vcs(struct fb_info *info) fbcon_modechanged(info); } +/* let fbcon check if it supports a new screen resolution */ +int fbcon_modechange_possible(struct fb_info *info, struct fb_var_screeninfo *var) +{
- struct fbcon_ops *ops = info->fbcon_par;
- struct vc_data *vc;
- unsigned int i;
- WARN_CONSOLE_UNLOCKED();
- if (!ops)
return 0;- /* prevent setting a screen size which is smaller than font size */
- for (i = first_fb_vc; i <= last_fb_vc; i++) {
vc = vc_cons[i].d;if (!vc || vc->vc_mode != KD_TEXT ||registered_fb[con2fb_map[i]] != info)continue;if (vc->vc_font.width > FBCON_SWAP(var->rotate, var->xres, var->yres) ||vc->vc_font.height > FBCON_SWAP(var->rotate, var->yres, var->xres))return -EINVAL;- }
- return 0;
+} +EXPORT_SYMBOL_GPL(fbcon_modechange_possible);
- static int fbcon_mode_deleted(struct fb_info *info, struct fb_videomode *mode) {
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 9087d467cc46..264e8ca5efa7 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1134,9 +1134,13 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, console_unlock(); return -ENODEV; }
info->flags |= FBINFO_MISC_USEREVENT;ret = fb_set_var(info, &var);info->flags &= ~FBINFO_MISC_USEREVENT;
ret = fbcon_modechange_possible(info, &var);if (!ret) {info->flags |= FBINFO_MISC_USEREVENT;ret = fb_set_var(info, &var);info->flags &= ~FBINFO_MISC_USEREVENT;}lock_fb_info(info);Why do we lock and unlock here consecutively?
Can it be a leftover?
Because in upstream commit, lock encapsulates `fb_set_var`, `fbcon_modechange_possible` and `fbcon_update_vcs` calls, which makes sense.
Here, it doesn't.
Thanks, lock_fb_info(info) is wrong here.
console_unlock(); if (!ret && copy_to_user(argp, &var, sizeof(var)))diff --git a/include/linux/fbcon.h b/include/linux/fbcon.h index f68a7db14165..39939d55c834 100644 --- a/include/linux/fbcon.h +++ b/include/linux/fbcon.h @@ -4,9 +4,13 @@ #ifdef CONFIG_FRAMEBUFFER_CONSOLE void __init fb_console_init(void); void __exit fb_console_exit(void); +int fbcon_modechange_possible(struct fb_info *info,
struct fb_var_screeninfo *var);+static inline int fbcon_modechange_possible(struct fb_info *info,
struct fb_var_screeninfo *var) { return 0; }#endif /* _LINUX_FBCON_H */
On Fri, Aug 05, 2022 at 06:22:03AM +0000, chenjun (AM) wrote:
在 2022/8/5 14:09, Cengiz Can 写道:
On Thu, 2022-08-04 at 12:27 +0000, Chen Jun wrote:
From: Helge Deller deller@gmx.de
commit e64242caef18b4a5840b0e7a9bff37abd4f4f933 upstream
We need to prevent that users configure a screen size which is smaller than the currently selected font size. Otherwise rendering chars on the screen will access memory outside the graphics memory region.
This patch adds a new function fbcon_modechange_possible() which implements this check and which later may be extended with other checks if necessary. The new function is called from the FBIOPUT_VSCREENINFO ioctl handler in fbmem.c, which will return -EINVAL if userspace asked for a too small screen size.
Signed-off-by: Helge Deller deller@gmx.de Reviewed-by: Geert Uytterhoeven geert@linux-m68k.org [Chen Jun: adjust context] Signed-off-by: Chen Jun chenjun102@huawei.com
drivers/video/fbdev/core/fbcon.c | 28 ++++++++++++++++++++++++++++ drivers/video/fbdev/core/fbmem.c | 10 +++++++--- include/linux/fbcon.h | 4 ++++ 3 files changed, 39 insertions(+), 3 deletions(-)
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index a97e94b1c84f..b84264e98929 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -2706,6 +2706,34 @@ static void fbcon_set_all_vcs(struct fb_info *info) fbcon_modechanged(info); } +/* let fbcon check if it supports a new screen resolution */ +int fbcon_modechange_possible(struct fb_info *info, struct fb_var_screeninfo *var) +{
- struct fbcon_ops *ops = info->fbcon_par;
- struct vc_data *vc;
- unsigned int i;
- WARN_CONSOLE_UNLOCKED();
- if (!ops)
return 0;- /* prevent setting a screen size which is smaller than font size */
- for (i = first_fb_vc; i <= last_fb_vc; i++) {
vc = vc_cons[i].d;if (!vc || vc->vc_mode != KD_TEXT ||registered_fb[con2fb_map[i]] != info)continue;if (vc->vc_font.width > FBCON_SWAP(var->rotate, var->xres, var->yres) ||vc->vc_font.height > FBCON_SWAP(var->rotate, var->yres, var->xres))return -EINVAL;- }
- return 0;
+} +EXPORT_SYMBOL_GPL(fbcon_modechange_possible);
- static int fbcon_mode_deleted(struct fb_info *info, struct fb_videomode *mode) {
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 9087d467cc46..264e8ca5efa7 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1134,9 +1134,13 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, console_unlock(); return -ENODEV; }
info->flags |= FBINFO_MISC_USEREVENT;ret = fb_set_var(info, &var);info->flags &= ~FBINFO_MISC_USEREVENT;
ret = fbcon_modechange_possible(info, &var);if (!ret) {info->flags |= FBINFO_MISC_USEREVENT;ret = fb_set_var(info, &var);info->flags &= ~FBINFO_MISC_USEREVENT;}lock_fb_info(info);Why do we lock and unlock here consecutively?
Can it be a leftover?
Because in upstream commit, lock encapsulates `fb_set_var`, `fbcon_modechange_possible` and `fbcon_update_vcs` calls, which makes sense.
Here, it doesn't.
Thanks, lock_fb_info(info) is wrong here.
Ok, I'm totally confused now.
I'm dropping all of these series from my queue now. Please fix them up and resend them for all pending stable trees (4.9.y, 4.14.y, and 4.19.y).
thanks,
greg k-h
From: Helge Deller deller@gmx.de
commit 6c11df58fd1ac0aefcb3b227f72769272b939e56 upstream
Verify that the fbdev or drm driver correctly adjusted the virtual screen sizes. On failure report the failing driver and reject the screen size change.
Signed-off-by: Helge Deller deller@gmx.de Reviewed-by: Geert Uytterhoeven geert@linux-m68k.org [Chen Jun: adjust context] Signed-off-by: Chen Jun chenjun102@huawei.com --- drivers/video/fbdev/core/fbmem.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 264e8ca5efa7..1238cc9f42c0 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1019,6 +1019,16 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var) if (ret) goto done;
+ /* verify that virtual resolution >= physical resolution */ + if (var->xres_virtual < var->xres || + var->yres_virtual < var->yres) { + pr_warn("WARNING: fbcon: Driver '%s' missed to adjust virtual screen size (%ux%u vs. %ux%u)\n", + info->fix.id, + var->xres_virtual, var->yres_virtual, + var->xres, var->yres); + return -EINVAL; + } + if ((var->activate & FB_ACTIVATE_MASK) == FB_ACTIVATE_NOW) { struct fb_var_screeninfo old_var; struct fb_videomode mode;
linux-stable-mirror@lists.linaro.org
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