linux-toradex.git/kernel/gcov, branch v5.12-rc5

gcov: fix clang-11+ support

2021-03-25T16:22:55+00:00

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 
Reported-by: Prasad Sodagudi 
Suggested-by: Nathan Chancellor 
Reviewed-by: Fangrui Song 
Tested-by: Nathan Chancellor 
Acked-by: Peter Oberparleiter 
Reviewed-by: Nathan Chancellor 
Cc: 	[5.4+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

init/gcov: allow CONFIG_CONSTRUCTORS on UML to fix module gcov

2021-02-05T19:03:47+00:00

On ARCH=um, loading a module doesn't result in its constructors getting
called, which breaks module gcov since the debugfs files are never
registered.  On the other hand, in-kernel constructors have already been
called by the dynamic linker, so we can't call them again.

Get out of this conundrum by allowing CONFIG_CONSTRUCTORS to be
selected, but avoiding the in-kernel constructor calls.

Also remove the "if !UML" from GCOV selecting CONSTRUCTORS now, since we
really do want CONSTRUCTORS, just not kernel binary ones.

Link: https://lkml.kernel.org/r/20210120172041.c246a2cac2fb.I1358f584b76f1898373adfed77f4462c8705b736@changeid
Signed-off-by: Johannes Berg 
Reviewed-by: Peter Oberparleiter 
Cc: Arnd Bergmann 
Cc: Jessica Yu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

gcov: fix kernel-doc markup issue

2020-12-16T06:46:18+00:00

Fix the following kernel-doc issue in gcov:

  kernel/gcov/gcc_4_7.c:238: warning: Function parameter or member 'dst' not described in 'gcov_info_add'
  kernel/gcov/gcc_4_7.c:238: warning: Function parameter or member 'src' not described in 'gcov_info_add'
  kernel/gcov/gcc_4_7.c:238: warning: Excess function parameter 'dest' description in 'gcov_info_add'
  kernel/gcov/gcc_4_7.c:238: warning: Excess function parameter 'source' description in 'gcov_info_add'

Link: https://lkml.kernel.org/r/1605252352-63983-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi 
Acked-by: Peter Oberparleiter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

gcov: remove support for GCC < 4.9

2020-12-16T06:46:18+00:00

Since commit 0bddd227f3dc ("Documentation: update for gcc 4.9
requirement") the minimum supported version of GCC is gcc-4.9.  It's now
safe to remove this code.

Similar to commit 10415533a906 ("gcov: Remove old GCC 3.4 support") but
that was for GCC 4.8 and this is for GCC 4.9.

Link: https://github.com/ClangBuiltLinux/linux/issues/427
Link: https://lkml.kernel.org/r/20201111030557.2015680-1-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers 
Reviewed-by: Peter Oberparleiter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

gcov: add support for GCC 10.1

2020-09-11T16:33:54+00:00

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 
Reported-by: Leon Romanovsky 
Signed-off-by: Peter Oberparleiter 
Tested-by: Leon Romanovsky 
Tested-and-Acked-by: Colin Ian King 
Signed-off-by: Linus Torvalds

gcov: Disable gcov build with GCC 10

2020-09-04T16:19:49+00:00

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 
Signed-off-by: Leon Romanovsky 
Signed-off-by: Linus Torvalds

treewide: replace '---help---' in Kconfig files with 'help'

2020-06-13T16:57:21+00:00

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada

gcov: Remove old GCC 3.4 support

2020-04-16T11:28:35+00:00

The kernel requires at least GCC 4.8 in order to build, and so there is
no need to cater for the pre-4.7 gcov format.

Remove the obsolete code.

Acked-by: Peter Oberparleiter 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Will Deacon

kernel/gcov/fs.c: gcov_seq_next() should increase position index

2020-04-10T22:36:22+00:00

If seq_file .next function does not change position index, read after
some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin 
Signed-off-by: Andrew Morton 
Acked-by: Peter Oberparleiter 
Cc: Al Viro 
Cc: Davidlohr Bueso 
Cc: Ingo Molnar 
Cc: Manfred Spraul 
Cc: NeilBrown 
Cc: Steven Rostedt 
Cc: Waiman Long 
Link: http://lkml.kernel.org/r/f65c6ee7-bd00-f910-2f8a-37cc67e4ff88@virtuozzo.com
Signed-off-by: Linus Torvalds

kernel/gcov/fs.c: replace zero-length array with flexible-array member

2020-04-07T17:43:44+00:00

The current codebase makes use of the zero-length array language extension
to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning in
case the flexible array does not occur last in the structure, which will
help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by this
change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied.  As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva 
Signed-off-by: Andrew Morton 
Cc: Peter Oberparleiter 
Link: http://lkml.kernel.org/r/20200302224851.GA26467@embeddedor
Signed-off-by: Linus Torvalds