gcov: add support for GCC 10.1

Using gcov to collect coverage data for kernels compiled with GCC 10.1
causes random malfunctions and kernel crashes.  This is the result of a
changed GCOV_COUNTERS value in GCC 10.1 that causes a mismatch between
the layout of the gcov_info structure created by GCC profiling code and
the related structure used by the kernel.

Fix this by updating the in-kernel GCOV_COUNTERS value.  Also re-enable
config GCOV_KERNEL for use with GCC 10.

Reported-by: Colin Ian King <colin.king@canonical.com>
Reported-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Tested-by: Leon Romanovsky <leonro@nvidia.com>
Tested-and-Acked-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig
index bb4b680e8455acdde880c21bdc7197dee5db9112..3110c77230c7f7729b7a4488680ee0003e1797f0 100644 (file)
--- a/kernel/gcov/Kconfig
+++ b/kernel/gcov/Kconfig
@@ -4,7 +4,6 @@ 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

diff --git a/kernel/gcov/gcc_4_7.c b/kernel/gcov/gcc_4_7.c
index 908fdf5098c32e088e1adff65d2c4f3f2472ecad..53c67c87f141bb483e1baa7a20546dac9c997263 100644 (file)
--- a/kernel/gcov/gcc_4_7.c
+++ b/kernel/gcov/gcc_4_7.c
@@ -19,7 +19,9 @@
 #include <linux/vmalloc.h>
 #include "gcov.h"
 
-#if (__GNUC__ >= 7)
+#if (__GNUC__ >= 10)
+#define GCOV_COUNTERS                  8
+#elif (__GNUC__ >= 7)
 #define GCOV_COUNTERS                  9
 #elif (__GNUC__ > 5) || (__GNUC__ == 5 && __GNUC_MINOR__ >= 1)
 #define GCOV_COUNTERS                  10