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40249c6962
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>
54 lines
1.4 KiB
Text
54 lines
1.4 KiB
Text
# SPDX-License-Identifier: GPL-2.0-only
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menu "GCOV-based kernel profiling"
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config GCOV_KERNEL
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bool "Enable gcov-based kernel profiling"
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depends on DEBUG_FS
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select CONSTRUCTORS if !UML
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default n
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help
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This option enables gcov-based code profiling (e.g. for code coverage
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measurements).
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If unsure, say N.
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Additionally specify CONFIG_GCOV_PROFILE_ALL=y to get profiling data
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for the entire kernel. To enable profiling for specific files or
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directories, add a line similar to the following to the respective
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Makefile:
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For a single file (e.g. main.o):
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GCOV_PROFILE_main.o := y
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For all files in one directory:
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GCOV_PROFILE := y
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To exclude files from being profiled even when CONFIG_GCOV_PROFILE_ALL
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is specified, use:
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GCOV_PROFILE_main.o := n
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and:
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GCOV_PROFILE := n
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Note that the debugfs filesystem has to be mounted to access
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profiling data.
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config ARCH_HAS_GCOV_PROFILE_ALL
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def_bool n
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config GCOV_PROFILE_ALL
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bool "Profile entire Kernel"
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depends on !COMPILE_TEST
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depends on GCOV_KERNEL
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depends on ARCH_HAS_GCOV_PROFILE_ALL
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default n
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help
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This options activates profiling for the entire kernel.
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If unsure, say N.
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Note that a kernel compiled with profiling flags will be significantly
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larger and run slower. Also be sure to exclude files from profiling
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which are not linked to the kernel image to prevent linker errors.
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endmenu
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