History log of /linux-master/tools/include/asm-generic/unaligned.h
Revision Date Author Comments
# fdd0ae72 31-Jan-2024 Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools headers: update the asm-generic/unaligned.h copy with the kernel sources

To pick up the changes in:

1ab33c03145d0f6c ("asm-generic: make sparse happy with odd-sized put_unaligned_*()")

Addressing this perf tools build warning:

Warning: Kernel ABI header differences:
diff -u tools/include/asm-generic/unaligned.h include/asm-generic/unaligned.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/Zbp9I7rmFj1Owhug@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# a399ee67 09-Nov-2023 Arnaldo Carvalho de Melo <acme@redhat.com>

tools: Disable __packed attribute compiler warning due to -Werror=attributes

Noticed on several perf tools cross build test containers:

[perfbuilder@five ~]$ grep FAIL ~/dm.log/summary
19 10.18 debian:experimental-x-mips : FAIL gcc version 12.3.0 (Debian 12.3.0-6)
20 11.21 debian:experimental-x-mips64 : FAIL gcc version 12.3.0 (Debian 12.3.0-6)
21 11.30 debian:experimental-x-mipsel : FAIL gcc version 12.3.0 (Debian 12.3.0-6)
37 12.07 ubuntu:18.04-x-arm : FAIL gcc version 7.5.0 (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04)
42 11.91 ubuntu:18.04-x-riscv64 : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
44 13.17 ubuntu:18.04-x-sh4 : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
45 12.09 ubuntu:18.04-x-sparc64 : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
[perfbuilder@five ~]$

In file included from util/intel-pt-decoder/intel-pt-pkt-decoder.c:10:
/tmp/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h: In function 'get_unaligned_le16':
/tmp/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h:13:29: error: packed attribute causes inefficient alignment for 'x' [-Werror=attributes]
13 | const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \
| ^
/tmp/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h:27:28: note: in expansion of macro '__get_unaligned_t'
27 | return le16_to_cpu(__get_unaligned_t(__le16, p));
| ^~~~~~~~~~~~~~~~~

This comes from the kernel, where the -Wattributes and -Wpacked isn't
used, -Wpacked is already disabled, do it for the attributes as well.

Fixes: a91c987254651443 ("perf tools: Add get_unaligned_leNN()")
Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/7c5b626c-1de9-4c12-a781-e44985b4a797@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 57686a72 09-Nov-2023 Arnaldo Carvalho de Melo <acme@redhat.com>

tools: Disable __packed attribute compiler warning due to -Werror=attributes

Noticed on several perf tools cross build test containers:

[perfbuilder@five ~]$ grep FAIL ~/dm.log/summary
19 10.18 debian:experimental-x-mips : FAIL gcc version 12.3.0 (Debian 12.3.0-6)
20 11.21 debian:experimental-x-mips64 : FAIL gcc version 12.3.0 (Debian 12.3.0-6)
21 11.30 debian:experimental-x-mipsel : FAIL gcc version 12.3.0 (Debian 12.3.0-6)
37 12.07 ubuntu:18.04-x-arm : FAIL gcc version 7.5.0 (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04)
42 11.91 ubuntu:18.04-x-riscv64 : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
44 13.17 ubuntu:18.04-x-sh4 : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
45 12.09 ubuntu:18.04-x-sparc64 : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
[perfbuilder@five ~]$

In file included from util/intel-pt-decoder/intel-pt-pkt-decoder.c:10:
/tmp/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h: In function 'get_unaligned_le16':
/tmp/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h:13:29: error: packed attribute causes inefficient alignment for 'x' [-Werror=attributes]
13 | const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \
| ^
/tmp/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h:27:28: note: in expansion of macro '__get_unaligned_t'
27 | return le16_to_cpu(__get_unaligned_t(__le16, p));
| ^~~~~~~~~~~~~~~~~

This comes from the kernel, where the -Wattributes and -Wpacked isn't
used, -Wpacked is already disabled, do it for the attributes as well.

Fixes: a91c987254651443 ("perf tools: Add get_unaligned_leNN()")
Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/7c5b626c-1de9-4c12-a781-e44985b4a797@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>


# a91c9872 05-Oct-2023 Adrian Hunter <adrian.hunter@intel.com>

perf tools: Add get_unaligned_leNN()

Add get_unaligned_le16(), get_unaligned_le32 and get_unaligned_le64, same
as include/asm-generic/unaligned.h. And add include/asm-generic/unaligned.h
to check-headers.sh bringing tools/include/asm-generic/unaligned.h up to
date so that the kernel and tools versions match.

Use diagnostic pragmas to ignore -Wpacked used by perf build.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20231005190451.175568-2-adrian.hunter@intel.com
Link: https://lore.kernel.org/r/20231010142234.20061-1-adrian.hunter@intel.com
[ squashed check-header.sh addition ]
Signed-off-by: Namhyung Kim <namhyung@kernel.org>


# f96b4675 29-Sep-2021 Borislav Petkov <bp@suse.de>

x86/insn: Use get_unaligned() instead of memcpy()

Use get_unaligned() instead of memcpy() to access potentially unaligned
memory, which, when accessed through a pointer, leads to undefined
behavior. get_unaligned() describes much better what is happening there
anyway even if memcpy() does the job.

In addition, since perf tool builds with -Werror, it would fire with:

util/intel-pt-decoder/../../../arch/x86/lib/insn.c: In function '__insn_get_emulate_prefix':
tools/include/../include/asm-generic/unaligned.h:10:15: error: packed attribute is unnecessary [-Werror=packed]
10 | const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \

because -Werror=packed would complain if the packed attribute would have
no effect on the layout of the structure.

In this case, that is intentional so disable the warning only for that
compilation unit.

That part is Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>

No functional changes.

Fixes: 5ba1071f7554 ("x86/insn, tools/x86: Fix undefined behavior due to potential unaligned accesses")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lkml.kernel.org/r/YVSsIkj9Z29TyUjE@zn.tnic