The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 0ca3418272a230a16d87d3302839d0ca1255f378 Mon Sep 17 00:00:00 2001

From: Takashi Iwai tiwai@suse.de Date: Fri, 23 Oct 2020 09:46:55 +0200 Subject: [PATCH] drm/amd/display: Don't invoke kgdb_breakpoint() unconditionally

ASSERT_CRITICAL() invokes kgdb_breakpoint() whenever either CONFIG_KGDB or CONFIG_HAVE_KGDB is set. This, however, may lead to a kernel panic when no kdb stuff is attached, since the kgdb_breakpoint() call issues INT3. It's nothing but a surprise for normal end-users.

For avoiding the pitfall, make the kgdb_breakpoint() call only when CONFIG_DEBUG_KERNEL_DC is set.

https://bugzilla.opensuse.org/show_bug.cgi?id=1177973 Cc: stable@vger.kernel.org Acked-by: Alex Deucher alexander.deucher@amd.com Reviewed-by: Nicholas Kazlauskas nicholas.kazlauskas@amd.com Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Alex Deucher alexander.deucher@amd.com

diff --git a/drivers/gpu/drm/amd/display/dc/os_types.h b/drivers/gpu/drm/amd/display/dc/os_types.h index 330acaaed79a..32758b245754 100644 --- a/drivers/gpu/drm/amd/display/dc/os_types.h +++ b/drivers/gpu/drm/amd/display/dc/os_types.h @@ -94,7 +94,7 @@ * general debug capabilities * */ -#if defined(CONFIG_HAVE_KGDB) || defined(CONFIG_KGDB) +#if defined(CONFIG_DEBUG_KERNEL_DC) && (defined(CONFIG_HAVE_KGDB) || defined(CONFIG_KGDB)) #define ASSERT_CRITICAL(expr) do { \ if (WARN_ON(!(expr))) { \ kgdb_breakpoint(); \