linux-stable.git/scripts, branch v5.4.48

bpf: Support llvm-objcopy for vmlinux BTF

2020-06-17T14:40:20+00:00

commit 90ceddcb495008ac8ba7a3dce297841efcd7d584 upstream.

Simplify gen_btf logic to make it work with llvm-objcopy. The existing
'file format' and 'architecture' parsing logic is brittle and does not
work with llvm-objcopy/llvm-objdump.

'file format' output of llvm-objdump>=11 will match GNU objdump, but
'architecture' (bfdarch) may not.

.BTF in .tmp_vmlinux.btf is non-SHF_ALLOC. Add the SHF_ALLOC flag
because it is part of vmlinux image used for introspection. C code
can reference the section via linker script defined __start_BTF and
__stop_BTF. This fixes a small problem that previous .BTF had the
SHF_WRITE flag (objcopy -I binary -O elf* synthesized .data).

Additionally, `objcopy -I binary` synthesized symbols
_binary__btf_vmlinux_bin_start and _binary__btf_vmlinux_bin_stop (not
used elsewhere) are replaced with more commonplace __start_BTF and
__stop_BTF.

Add 2>/dev/null because GNU objcopy (but not llvm-objcopy) warns
"empty loadable segment detected at vaddr=0xffffffff81000000, is this intentional?"

We use a dd command to change the e_type field in the ELF header from
ET_EXEC to ET_REL so that lld will accept .btf.vmlinux.bin.o.  Accepting
ET_EXEC as an input file is an extremely rare GNU ld feature that lld
does not intend to support, because this is error-prone.

The output section description .BTF in include/asm-generic/vmlinux.lds.h
avoids potential subtle orphan section placement issues and suppresses
--orphan-handling=warn warnings.

Fixes: df786c9b9476 ("bpf: Force .BTF section start to zero when dumping from vmlinux")
Fixes: cb0cc635c7a9 ("powerpc: Include .BTF section")
Reported-by: Nathan Chancellor 
Signed-off-by: Fangrui Song 
Signed-off-by: Daniel Borkmann 
Tested-by: Stanislav Fomichev 
Tested-by: Andrii Nakryiko 
Reviewed-by: Stanislav Fomichev 
Reviewed-by: Kees Cook 
Acked-by: Andrii Nakryiko 
Acked-by: Michael Ellerman  (powerpc)
Link: https://github.com/ClangBuiltLinux/linux/issues/871
Link: https://lore.kernel.org/bpf/20200318222746.173648-1-maskray@google.com
Signed-off-by: Maria Teguiani 
Tested-by: Matthias Maennich 
Signed-off-by: Greg Kroah-Hartman

kbuild: Remove debug info from kallsyms linking

2020-05-27T15:46:44+00:00

[ Upstream commit af73d78bd384aa9b8789aa6e7ddbb165f971276f ]

When CONFIG_DEBUG_INFO is enabled, the two kallsyms linking steps spend
time collecting and writing the dwarf sections to the temporary output
files. kallsyms does not need this information, and leaving it off
halves their linking time. This is especially noticeable without
CONFIG_DEBUG_INFO_REDUCED. The BTF linking stage, however, does still
need those details.

Refactor the BTF and kallsyms generation stages slightly for more
regularized temporary names. Skip debug during kallsyms links.
Additionally move "info BTF" to the correct place since commit
8959e39272d6 ("kbuild: Parameterize kallsyms generation and correct
reporting"), which added "info LD ..." to vmlinux_link calls.

For a full debug info build with BTF, my link time goes from 1m06s to
0m54s, saving about 12 seconds, or 18%.

Signed-off-by: Kees Cook 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/202003031814.4AEA3351@keescook
Signed-off-by: Sasha Levin

scripts/gdb: repair rb_first() and rb_last()

2020-05-27T15:46:36+00:00

[ Upstream commit 50e36be1fb9572b2e4f2753340bdce3116bf2ce7 ]

The current implementations of the rb_first() and rb_last() gdb
functions have a variable that references itself in its instanciation,
which causes the function to throw an error if a specific condition on
the argument is met.  The original author rather intended to reference
the argument and made a typo.  Referring the argument instead makes the
function work as intended.

Signed-off-by: Aymeric Agon-Rambosson 
Signed-off-by: Andrew Morton 
Reviewed-by: Stephen Boyd 
Cc: Jan Kiszka 
Cc: Kieran Bingham 
Cc: Douglas Anderson 
Cc: Nikolay Borisov 
Cc: Jackie Liu 
Cc: Jason Wessel 
Link: http://lkml.kernel.org/r/20200427051029.354840-1-aymeric.agon@yandex.com
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

gcc-common.h: Update for GCC 10

2020-05-27T15:46:24+00:00

[ Upstream commit c7527373fe28f97d8a196ab562db5589be0d34b9 ]

Remove "params.h" include, which has been dropped in GCC 10.

Remove is_a_helper() macro, which is now defined in gimple.h, as seen
when running './scripts/gcc-plugin.sh g++ g++ gcc':

In file included from :1:
./gcc-plugins/gcc-common.h:852:13: error: redefinition of ‘static bool is_a_helper::test(U*) [with U = const gimple; T = const ggoto*]’
  852 | inline bool is_a_helper::test(const_gimple gs)
      |             ^~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from ./gcc-plugins/gcc-common.h:125,
                 from :1:
/usr/lib/gcc/x86_64-redhat-linux/10/plugin/include/gimple.h:1037:1: note: ‘static bool is_a_helper::test(U*) [with U = const gimple; T = const ggoto*]’ previously declared here
 1037 | is_a_helper ::test (const gimple *gs)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~

Add -Wno-format-diag to scripts/gcc-plugins/Makefile to avoid
meaningless warnings from error() formats used by plugins:

scripts/gcc-plugins/structleak_plugin.c: In function ‘int plugin_init(plugin_name_args*, plugin_gcc_version*)’:
scripts/gcc-plugins/structleak_plugin.c:253:12: warning: unquoted sequence of 2 consecutive punctuation characters ‘'-’ in format [-Wformat-diag]
  253 |   error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key);
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Frédéric Pierret (fepitre) 
Link: https://lore.kernel.org/r/20200407113259.270172-1-frederic.pierret@qubes-os.org
[kees: include -Wno-format-diag for plugin builds]
Signed-off-by: Kees Cook 
Signed-off-by: Sasha Levin

scripts/decodecode: fix trapping instruction formatting

2020-05-14T05:58:29+00:00

commit e08df079b23e2e982df15aa340bfbaf50f297504 upstream.

If the trapping instruction contains a ':', for a memory access through
segment registers for example, the sed substitution will insert the '*'
marker in the middle of the instruction instead of the line address:

	2b:   65 48 0f c7 0f          cmpxchg16b %gs:*(%rdi)          <-- trapping instruction

I started to think I had forgotten some quirk of the assembly syntax
before noticing that it was actually coming from the script.  Fix it to
add the address marker at the right place for these instructions:

	28:   49 8b 06                mov    (%r14),%rax
	2b:*  65 48 0f c7 0f          cmpxchg16b %gs:(%rdi)           <-- trapping instruction
	30:   0f 94 c0                sete   %al

Fixes: 18ff44b189e2 ("scripts/decodecode: make faulting insn ptr more robust")
Signed-off-by: Ivan Delalande 
Signed-off-by: Andrew Morton 
Reviewed-by: Borislav Petkov 
Link: http://lkml.kernel.org/r/20200419223653.GA31248@visor
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

scripts/config: allow colons in option strings for sed

2020-05-10T08:31:27+00:00

[ Upstream commit e461bc9f9ab105637b86065d24b0b83f182d477c ]

Sed broke on some strings as it used colon as a separator.
I made it more robust by using \001, which is legit POSIX AFAIK.

E.g. ./config --set-str CONFIG_USBNET_DEVADDR "de:ad:be:ef:00:01"
failed with: sed: -e expression #1, char 55: unknown option to `s'

Signed-off-by: Jeremie Francois (on alpha) 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

kbuild: fix DT binding schema rule again to avoid needless rebuilds

2020-05-02T06:48:42+00:00

commit 3d4b2238684ac919394eba7fb51bb7eeeec6ab57 upstream.

Since commit 7a0496056064 ("kbuild: fix DT binding schema rule to detect
command line changes"), this rule is every time re-run even if you change
nothing.

cmd_dtc takes one additional parameter to pass to the -O option of dtc.

We need to pass 'yaml' to if_changed_rule. Otherwise, cmd-check invoked
from if_changed_rule is false positive.

Fixes: 7a0496056064 ("kbuild: fix DT binding schema rule to detect command line changes")
Signed-off-by: Masahiro Yamada 
Signed-off-by: Greg Kroah-Hartman

kconfig: qconf: Fix a few alignment issues

2020-04-29T14:33:00+00:00

[ Upstream commit 60969f02f07ae1445730c7b293c421d179da729c ]

There are a few items with wrong alignments. Solve them.

Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

kconfig: introduce m32-flag and m64-flag

2020-04-08T07:08:37+00:00

[ Upstream commit 8cc4fd73501d9f1370c3eebb70cfe8cc9e24062b ]

When a compiler supports multiple architectures, some compiler features
can be dependent on the target architecture.

This is typical for Clang, which supports multiple LLVM backends.
Even for GCC, we need to take care of biarch compiler cases.

It is not a problem when we evaluate cc-option in Makefiles because
cc-option is tested against the flag in question + $(KBUILD_CFLAGS).

The cc-option in Kconfig, on the other hand, does not accumulate
tested flags. Due to this simplification, it could potentially test
cc-option against a different target.

At first, Kconfig always evaluated cc-option against the host
architecture.

Since commit e8de12fb7cde ("kbuild: Check for unknown options with
cc-option usage in Kconfig and clang"), in case of cross-compiling
with Clang, the target triple is correctly passed to Kconfig.

The case with biarch GCC (and native build with Clang) is still not
handled properly. We need to pass some flags to specify the target
machine bit.

Due to the design, all the macros in Kconfig are expanded in the
parse stage, where we do not know the target bit size yet.

For example, arch/x86/Kconfig allows a user to toggle CONFIG_64BIT.
If a compiler flag -foo depends on the machine bit, it must be tested
twice, one with -m32 and the other with -m64.

However, -m32/-m64 are not always recognized. So, this commits adds
m64-flag and m32-flag macros. They expand to -m32, -m64, respectively
if supported. Or, they expand to an empty string if unsupported.

The typical usage is like this:

  config FOO
          bool
          default $(cc-option,$(m64-flag) -foo) if 64BIT
          default $(cc-option,$(m32-flag) -foo)

This is clumsy, but there is no elegant way to handle this in the
current static macro expansion.

There was discussion for static functions vs dynamic functions.
The consensus was to go as far as possible with the static functions.
(https://lkml.org/lkml/2018/3/2/22)

Signed-off-by: Masahiro Yamada 
Tested-by: George Spelvin 
Reviewed-by: Nathan Chancellor 
Signed-off-by: Sasha Levin

scripts/dtc: Remove redundant YYLOC global declaration

2020-04-01T09:02:00+00:00

commit e33a814e772cdc36436c8c188d8c42d019fda639 upstream.

gcc 10 will default to -fno-common, which causes this error at link
time:

  (.text+0x0): multiple definition of `yylloc'; dtc-lexer.lex.o (symbol from plugin):(.text+0x0): first defined here

This is because both dtc-lexer as well as dtc-parser define the same
global symbol yyloc. Before with -fcommon those were merged into one
defintion. The proper solution would be to to mark this as "extern",
however that leads to:

  dtc-lexer.l:26:16: error: redundant redeclaration of 'yylloc' [-Werror=redundant-decls]
   26 | extern YYLTYPE yylloc;
      |                ^~~~~~
In file included from dtc-lexer.l:24:
dtc-parser.tab.h:127:16: note: previous declaration of 'yylloc' was here
  127 | extern YYLTYPE yylloc;
      |                ^~~~~~
cc1: all warnings being treated as errors

which means the declaration is completely redundant and can just be
dropped.

Signed-off-by: Dirk Mueller 
Signed-off-by: David Gibson 
[robh: cherry-pick from upstream]
Cc: stable@vger.kernel.org
Signed-off-by: Rob Herring 
Signed-off-by: Greg Kroah-Hartman