linux-stable.git/kernel, branch v5.4.68

kprobes: fix kill kprobe which has been marked as gone

2020-09-26T16:03:11+00:00

[ Upstream commit b0399092ccebd9feef68d4ceb8d6219a8c0caa05 ]

If a kprobe is marked as gone, we should not kill it again.  Otherwise, we
can disarm the kprobe more than once.  In that case, the statistics of
kprobe_ftrace_enabled can unbalance which can lead to that kprobe do not
work.

Fixes: e8386a0cb22f ("kprobes: support probing module __exit function")
Co-developed-by: Chengming Zhou 
Signed-off-by: Muchun Song 
Signed-off-by: Chengming Zhou 
Signed-off-by: Andrew Morton 
Acked-by: Masami Hiramatsu 
Cc: "Naveen N . Rao" 
Cc: Anil S Keshavamurthy 
Cc: David S. Miller 
Cc: Song Liu 
Cc: Steven Rostedt 
Cc: 
Link: https://lkml.kernel.org/r/20200822030055.32383-1-songmuchun@bytedance.com
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

gcov: add support for GCC 10.1

2020-09-17T11:47:56+00:00

[ Upstream commit 40249c6962075c040fd071339acae524f18bfac9 ]

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 
Signed-off-by: Sasha Levin

gcov: Disable gcov build with GCC 10

2020-09-17T11:47:49+00:00

[ 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 
Signed-off-by: Leon Romanovsky 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

kbuild: add variables for compression tools

2020-09-03T09:27:10+00:00

commit 8dfb61dcbaceb19a5ded5e9c9dcf8d05acc32294 upstream.

Allow user to use alternative implementations of compression tools,
such as pigz, pbzip2, pxz. For example, multi-threaded tools to
speed up the build:
$ make GZIP=pigz BZIP2=pbzip2

Variables _GZIP, _BZIP2, _LZOP are used internally because original env
vars are reserved by the tools. The use of GZIP in gzip tool is obsolete
since 2015. However, alternative implementations (e.g., pigz) still rely
on it. BZIP2, BZIP, LZOP vars are not obsolescent.

The credit goes to @grsecurity.

As a sidenote, for multi-threaded lzma, xz compression one can use:
$ export XZ_OPT="--threads=0"

Signed-off-by: Denis Efremov 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Matthias Maennich 
Signed-off-by: Greg Kroah-Hartman

kheaders: explain why include/config/autoconf.h is excluded from md5sum

2020-09-03T09:27:10+00:00

commit f276031b4e2f4c961ed6d8a42f0f0124ccac2e09 upstream.

This comment block explains why include/generated/compile.h is omitted,
but nothing about include/generated/autoconf.h, which might be more
difficult to understand. Add more comments.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Matthias Maennich 
Signed-off-by: Greg Kroah-Hartman

kheaders: remove the last bashism to allow sh to run it

2020-09-03T09:27:10+00:00

commit 1463f74f492eea7191f0178e01f3d38371a48210 upstream.

'pushd' ... 'popd' is the last bash-specific code in this script.
One way to avoid it is to run the code in a sub-shell.

With that addressed, you can run this script with sh.

I replaced $(BASH) with $(CONFIG_SHELL), and I changed the hashbang
to #!/bin/sh.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Matthias Maennich 
Signed-off-by: Greg Kroah-Hartman

kheaders: optimize header copy for in-tree builds

2020-09-03T09:27:10+00:00

commit ea79e5168be644fdaf7d4e6a73eceaf07b3da76a upstream.

This script copies headers by the cpio command twice; first from
srctree, and then from objtree. However, when we building in-tree,
we know the srctree and the objtree are the same. That is, all the
headers copied by the first cpio are overwritten by the second one.

Skip the first cpio when we are building in-tree.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Matthias Maennich 
Signed-off-by: Greg Kroah-Hartman

kheaders: optimize md5sum calculation for in-tree builds

2020-09-03T09:27:10+00:00

commit 0e11773e76098729552b750ccff79374d1e62002 upstream.

This script computes md5sum of headers in srctree and in objtree.
However, when we are building in-tree, we know the srctree and the
objtree are the same. That is, we end up with the same computation
twice. In fact, the first two lines of kernel/kheaders.md5 are always
the same for in-tree builds.

Unify the two md5sum calculations.

For in-tree builds ($building_out_of_srctree is empty), we check
only two directories, "include", and "arch/$SRCARCH/include".

For out-of-tree builds ($building_out_of_srctree is 1), we check
4 directories, "$srctree/include", "$srctree/arch/$SRCARCH/include",
"include", and "arch/$SRCARCH/include" since we know they are all
different.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Matthias Maennich 
Signed-off-by: Greg Kroah-Hartman

kheaders: remove unneeded 'cat' command piped to 'head' / 'tail'

2020-09-03T09:27:09+00:00

commit 9a066357184485784f782719093ff804d05b85db upstream.

The 'head' and 'tail' commands can take a file path directly.
So, you do not need to run 'cat'.

  cat kernel/kheaders.md5 | head -1

... is equivalent to:

  head -1 kernel/kheaders.md5

and the latter saves forking one process.

While I was here, I replaced 'head -1' with 'head -n 1'.

I also replaced '==' with '=' since we do not have a good reason to
use the bashism.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Matthias Maennich 
Signed-off-by: Greg Kroah-Hartman

genirq/matrix: Deal with the sillyness of for_each_cpu() on UP

2020-09-03T09:27:06+00:00

commit 784a0830377d0761834e385975bc46861fea9fa0 upstream.

Most of the CPU mask operations behave the same way, but for_each_cpu() and
it's variants ignore the cpumask argument and claim that CPU0 is always in
the mask. This is historical, inconsistent and annoying behaviour.

The matrix allocator uses for_each_cpu() and can be called on UP with an
empty cpumask. The calling code does not expect that this succeeds but
until commit e027fffff799 ("x86/irq: Unbreak interrupt affinity setting")
this went unnoticed. That commit added a WARN_ON() to catch cases which
move an interrupt from one vector to another on the same CPU. The warning
triggers on UP.

Add a check for the cpumask being empty to prevent this.

Fixes: 2f75d9e1c905 ("genirq: Implement bitmap matrix allocator")
Reported-by: kernel test robot 
Signed-off-by: Thomas Gleixner 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman