The following commit has been merged into the x86/urgent branch of tip: Commit-ID: 3cb73bc3fa2a3cb80b88aa63b48409939e0d996b Gitweb: https://git.kernel.org/tip/3cb73bc3fa2a3cb80b88aa63b48409939e0d996b Author: Kairui Song <kas...@redhat.com> AuthorDate: Wed, 14 Oct 2020 17:24:29 +08:00 Committer: Ingo Molnar <mi...@kernel.org> CommitterDate: Wed, 14 Oct 2020 17:05:26 +02:00
hyperv_fb: Update screen_info after removing old framebuffer On gen2 HyperV VM, hyperv_fb will remove the old framebuffer, and the new allocated framebuffer address could be at a differnt location, and it might be no longer a VGA framebuffer. Update screen_info so that after kexec the kernel won't try to reuse the old invalid/stale framebuffer address as VGA, corrupting memory. [ mingo: Tidied up the changelog. ] Signed-off-by: Kairui Song <kas...@redhat.com> Signed-off-by: Ingo Molnar <mi...@kernel.org> Cc: Dexuan Cui <de...@microsoft.com> Cc: Jake Oshins <ja...@microsoft.com> Cc: Wei Hu <w...@microsoft.com> Cc: "K. Y. Srinivasan" <k...@microsoft.com> Cc: Haiyang Zhang <haiya...@microsoft.com> Cc: Stephen Hemminger <sthem...@microsoft.com> Link: https://lore.kernel.org/r/20201014092429.1415040-3-kas...@redhat.com --- drivers/video/fbdev/hyperv_fb.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c index 02411d8..e36fb1a 100644 --- a/drivers/video/fbdev/hyperv_fb.c +++ b/drivers/video/fbdev/hyperv_fb.c @@ -1114,8 +1114,15 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info) getmem_done: remove_conflicting_framebuffers(info->apertures, KBUILD_MODNAME, false); - if (!gen2vm) + + if (gen2vm) { + /* framebuffer is reallocated, clear screen_info to avoid misuse from kexec */ + screen_info.lfb_size = 0; + screen_info.lfb_base = 0; + screen_info.orig_video_isVGA = 0; + } else { pci_dev_put(pdev); + } kfree(info->apertures); return 0;
