On 6/25/22 15:03, Daniel Vetter wrote: > On Sat, Jun 25, 2022 at 02:25:02PM +0200, Helge Deller wrote: >> Make sure that we catch, report and fix up fbdev and drm graphic drivers which >> got the virtual screen resolution smaller than the physical screen resolution. >> >> Signed-off-by: Helge Deller <deller@xxxxxx> >> Cc: stable@xxxxxxxxxxxxxxx # v5.4+ > > No cc: stable for this, it's not fixing any bugs just helps validate > driver code. Ok. > Also if you just move the check from the ioctl code to here we don't need > to duplicate anything (and drivers which don't check their set_var are > kinda busted no matter what). See previous mail. We need to decide which way we go, then I'll change it. Thanks! Helge > -Daniel > >> --- >> drivers/video/fbdev/core/fbmem.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c >> index 50fb66b954d6..6d262e341023 100644 >> --- a/drivers/video/fbdev/core/fbmem.c >> +++ b/drivers/video/fbdev/core/fbmem.c >> @@ -1006,6 +1006,12 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var) >> if (var->xres < 8 || var->yres < 8) >> return -EINVAL; >> >> + /* make sure virtual resolution >= physical resolution */ >> + if (WARN_ON(var->xres_virtual < var->xres)) >> + var->xres_virtual = var->xres; >> + if (WARN_ON(var->yres_virtual < var->yres)) >> + var->yres_virtual = var->yres; >> + >> /* Too huge resolution causes multiplication overflow. */ >> if (check_mul_overflow(var->xres, var->yres, &unused) || >> check_mul_overflow(var->xres_virtual, var->yres_virtual, &unused)) >> -- >> 2.35.3 >> >
