commit 9562fd132985ea9185388a112e50f2a51557827d upstream.
LLVM changed the expected function signature for llvm_gcda_emit_function()
in the clang-11 release. Users of clang-11 or newer may have noticed
their kernels producing invalid coverage information:
$ llvm-cov gcov -a -c -u -f -b <input>.gcda -- gcno=<input>.gcno
1 <func>: checksum mismatch, \
(<lineno chksum A>, <cfg chksum B>) != (<lineno chksum A>, <cfg chksum C>)
2 Invalid .gcda File!
...
Fix up the function signatures so calling this function interprets its
parameters correctly and computes the correct cfg checksum. In
particular, in clang-11, the additional checksum is no longer optional.
Link: https://reviews.llvm.org/rG25544ce2df0daa4304c07e64b9c8b0f7df60c11d
Link: https://lkml.kernel.org/r/20210408184631.1156669-1-ndesaulniers@google.com
Reported-by: Prasad Sodagudi <psodagud@quicinc.com>
Tested-by: Prasad Sodagudi <psodagud@quicinc.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Cc: <stable@vger.kernel.org> [5.4+]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 60bcf728ee7c60ac2a1f9a0eaceb3a7b3954cd2b upstream.
LLVM changed the expected function signatures for llvm_gcda_start_file()
and llvm_gcda_emit_function() in the clang-11 release. Users of
clang-11 or newer may have noticed their kernels failing to boot due to
a panic when enabling CONFIG_GCOV_KERNEL=y +CONFIG_GCOV_PROFILE_ALL=y.
Fix up the function signatures so calling these functions doesn't panic
the kernel.
Link: https://reviews.llvm.org/rGcdd683b516d147925212724b09ec6fb792a40041
Link: https://reviews.llvm.org/rG13a633b438b6500ecad9e4f936ebadf3411d0f44
Link: https://lkml.kernel.org/r/20210312224132.3413602-2-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reported-by: Prasad Sodagudi <psodagud@quicinc.com>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Cc: <stable@vger.kernel.org> [5.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LLVM uses profiling data that's deliberately similar to GCC, but has a
very different way of exporting that data. LLVM calls llvm_gcov_init()
once per module, and provides a couple of callbacks that we can use to
ask for more data.
We care about the "writeout" callback, which in turn calls back into
compiler-rt/this module to dump all the gathered coverage data to disk:
llvm_gcda_start_file()
llvm_gcda_emit_function()
llvm_gcda_emit_arcs()
llvm_gcda_emit_function()
llvm_gcda_emit_arcs()
[... repeats for each function ...]
llvm_gcda_summary_info()
llvm_gcda_end_file()
This design is much more stateless and unstructured than gcc's, and is
intended to run at process exit. This forces us to keep some local
state about which module we're dealing with at the moment. On the other
hand, it also means we don't depend as much on how LLVM represents
profiling data internally.
See LLVM's lib/Transforms/Instrumentation/GCOVProfiling.cpp for more
details on how this works, particularly GCOVProfiler::emitProfileArcs(),
GCOVProfiler::insertCounterWriteout(), and GCOVProfiler::insertFlush().
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20190417225328.208129-1-trong@android.com
Signed-off-by: Greg Hackmann <ghackmann@android.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Tri Vo <trong@android.com>
Co-developed-by: Nick Desaulniers <ndesaulniers@google.com>
Co-developed-by: Tri Vo <trong@android.com>
Tested-by: Trilok Soni <tsoni@quicinc.com>
Tested-by: Prasad Sodagudi <psodagud@quicinc.com>
Tested-by: Tri Vo <trong@android.com>
Tested-by: Daniel Mentz <danielmentz@google.com>
Tested-by: Petri Gynther <pgynther@google.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
