From: Thomas Zimmermann Date: Fri, 19 Apr 2024 08:28:59 +0000 (+0200) Subject: fbdev/deferred-io: Always call get_page() for framebuffer pages X-Git-Tag: v6.11-rc1~141^2~24^2~235 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1ecbc7dd29020d335e1f6f789c23b36a84cd5214;p=thirdparty%2Fkernel%2Flinux.git fbdev/deferred-io: Always call get_page() for framebuffer pages Unconditionally call get_page() after looking up a page from the framebuffer memory. Guarantees that we always hold a reference. This change also refactors the code such that it can support a driver-supplied get_page helper. This will be useful for DRM's fbdev emulation. Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20240419083331.7761-7-tzimmermann@suse.de --- diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c index 37910753759cd..c68c51d0ef70e 100644 --- a/drivers/video/fbdev/core/fb_defio.c +++ b/drivers/video/fbdev/core/fb_defio.c @@ -23,7 +23,7 @@ #include #include -static struct page *fb_deferred_io_page(struct fb_info *info, unsigned long offs) +static struct page *fb_deferred_io_get_page(struct fb_info *info, unsigned long offs) { const void *screen_buffer = info->screen_buffer; struct page *page = NULL; @@ -33,6 +33,9 @@ static struct page *fb_deferred_io_page(struct fb_info *info, unsigned long offs else if (info->fix.smem_start) page = pfn_to_page((info->fix.smem_start + offs) >> PAGE_SHIFT); + if (page) + get_page(page); + return page; } @@ -129,12 +132,10 @@ static vm_fault_t fb_deferred_io_fault(struct vm_fault *vmf) if (offset >= info->fix.smem_len) return VM_FAULT_SIGBUS; - page = fb_deferred_io_page(info, offset); + page = fb_deferred_io_get_page(info, offset); if (!page) return VM_FAULT_SIGBUS; - get_page(page); - if (vmf->vma->vm_file) page->mapping = vmf->vma->vm_file->f_mapping; else