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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Colin Ian King <colin.king@canonical.com>,
        Leon Romanovsky <leonro@nvidia.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.4 09/46] gcov: Disable gcov build with GCC 10
Date:   Mon, 21 Sep 2020 18:27:25 +0200
Message-Id: <20200921162033.802338275@linuxfoundation.org>
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From: Leon Romanovsky <leonro@nvidia.com>

[ Upstream commit cfc905f158eaa099d6258031614d11869e7ef71c ]

GCOV built with GCC 10 doesn't initialize n_function variable.  This
produces different kernel panics as was seen by Colin in Ubuntu and me
in FC 32.

As a workaround, let's disable GCOV build for broken GCC 10 version.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1891288
Link: https://lore.kernel.org/lkml/20200827133932.3338519-1-leon@kernel.org
Link: https://lore.kernel.org/lkml/CAHk-=whbijeSdSvx-Xcr0DPMj0BiwhJ+uiNnDSVZcr_h_kg7UA@mail.gmail.com/
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/gcov/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig
index 1276aabaab550..1d78ed19a3512 100644
--- a/kernel/gcov/Kconfig
+++ b/kernel/gcov/Kconfig
@@ -3,6 +3,7 @@ menu "GCOV-based kernel profiling"
 config GCOV_KERNEL
 	bool "Enable gcov-based kernel profiling"
 	depends on DEBUG_FS
+	depends on !CC_IS_GCC || GCC_VERSION < 100000
 	select CONSTRUCTORS if !UML
 	default n
 	---help---
-- 
2.25.1