linux-stable.git/tools/include, branch linux-5.4.y

tools: move alignment-related macros to new

2024-09-04T11:15:02+00:00

commit 10a04ff09bcc39e0044190ffe9f00f998f13647c upstream.

Currently, tools have *ALIGN*() macros scattered across the unrelated
headers, as there are only 3 of them and they were added separately
each time on an as-needed basis.
Anyway, let's make it more consistent with the kernel headers and allow
using those macros outside of the mentioned headers. Create
 inside the tools/ folder and include it where needed.

Signed-off-by: Yury Norov 
Signed-off-by: Alexander Lobakin 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

bitmap: introduce generic optimized bitmap_size()

2024-09-04T11:14:50+00:00

commit a37fbe666c016fd89e4460d0ebfcea05baba46dc upstream.

The number of times yet another open coded
`BITS_TO_LONGS(nbits) * sizeof(long)` can be spotted is huge.
Some generic helper is long overdue.

Add one, bitmap_size(), but with one detail.
BITS_TO_LONGS() uses DIV_ROUND_UP(). The latter works well when both
divident and divisor are compile-time constants or when the divisor
is not a pow-of-2. When it is however, the compilers sometimes tend
to generate suboptimal code (GCC 13):

48 83 c0 3f          	add    $0x3f,%rax
48 c1 e8 06          	shr    $0x6,%rax
48 8d 14 c5 00 00 00 00	lea    0x0(,%rax,8),%rdx

%BITS_PER_LONG is always a pow-2 (either 32 or 64), but GCC still does
full division of `nbits + 63` by it and then multiplication by 8.
Instead of BITS_TO_LONGS(), use ALIGN() and then divide by 8. GCC:

8d 50 3f             	lea    0x3f(%rax),%edx
c1 ea 03             	shr    $0x3,%edx
81 e2 f8 ff ff 1f    	and    $0x1ffffff8,%edx

Now it shifts `nbits + 63` by 3 positions (IOW performs fast division
by 8) and then masks bits[2:0]. bloat-o-meter:

add/remove: 0/0 grow/shrink: 20/133 up/down: 156/-773 (-617)

Clang does it better and generates the same code before/after starting
from -O1, except that with the ALIGN() approach it uses %edx and thus
still saves some bytes:

add/remove: 0/0 grow/shrink: 9/133 up/down: 18/-538 (-520)

Note that we can't expand DIV_ROUND_UP() by adding a check and using
this approach there, as it's used in array declarations where
expressions are not allowed.
Add this helper to tools/ as well.

Reviewed-by: Przemek Kitszel 
Acked-by: Yury Norov 
Signed-off-by: Alexander Lobakin 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

hugetlb_encode.h: fix undefined behaviour (34 << 26)

2024-07-05T07:08:20+00:00

commit 710bb68c2e3a24512e2d2bae470960d7488e97b1 upstream.

Left-shifting past the size of your datatype is undefined behaviour in C.
The literal 34 gets the type `int`, and that one is not big enough to be
left shifted by 26 bits.

An `unsigned` is long enough (on any machine that has at least 32 bits for
their ints.)

For uniformity, we mark all the literals as unsigned.  But it's only
really needed for HUGETLB_FLAG_ENCODE_16GB.

Thanks to Randy Dunlap for an initial review and suggestion.

Link: https://lkml.kernel.org/r/20220905031904.150925-1-matthias.goergens@gmail.com
Signed-off-by: Matthias Goergens 
Acked-by: Randy Dunlap 
Cc: Mike Kravetz 
Cc: Muchun Song 
Signed-off-by: Andrew Morton 
[cmllamas: fix trivial conflict due to missing page encondigs]
Signed-off-by: Carlos Llamas 
Signed-off-by: Greg Kroah-Hartman

tools headers UAPI: Sync linux/perf_event.h with the kernel sources

2023-12-13T17:18:17+00:00

commit 65ba872a6971c11ceb342c3330f059289c0e6bdb upstream.

To pick the trivial change in:

  119a784c81270eb8 ("perf/core: Add a new read format to get a number of lost samples")

Signed-off-by: Namhyung Kim 
Acked-by: Jiri Olsa 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20220819003644.508916-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

bpf: Clarify error expectations from bpf_clone_redirect

2023-10-10T19:46:40+00:00

[ Upstream commit 7cb779a6867fea00b4209bcf6de2f178a743247d ]

Commit 151e887d8ff9 ("veth: Fixing transmit return status for dropped
packets") exposed the fact that bpf_clone_redirect is capable of
returning raw NET_XMIT_XXX return codes.

This is in the conflict with its UAPI doc which says the following:
"0 on success, or a negative error in case of failure."

Update the UAPI to reflect the fact that bpf_clone_redirect can
return positive error numbers, but don't explicitly define
their meaning.

Reported-by: Daniel Borkmann 
Signed-off-by: Stanislav Fomichev 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20230911194731.286342-1-sdf@google.com
Signed-off-by: Sasha Levin

tools/nolibc/string: Fix memcmp() implementation

2022-11-10T16:57:55+00:00

commit b3f4f51ea68a495f8a5956064c33dce711a2df91 upstream.

The C standard says that memcmp() must treat the buffers as consisting
of "unsigned chars". If char happens to be unsigned, the casts are ok,
but then obviously the c1 variable can never contain a negative
value. And when char is signed, the casts are wrong, and there's still
a problem with using an 8-bit quantity to hold the difference, because
that can range from -255 to +255.

For example, assuming char is signed, comparing two 1-byte buffers,
one containing 0x00 and another 0x80, the current implementation would
return -128 for both memcmp(a, b, 1) and memcmp(b, a, 1), whereas one
of those should of course return something positive.

Signed-off-by: Rasmus Villemoes 
Fixes: 66b6f755ad45 ("rcutorture: Import a copy of nolibc")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney 
Signed-off-by: Greg Kroah-Hartman

selftests/bpf: Extend verifier and bpf_sock tests for dst_port loads

2022-08-11T10:57:51+00:00

commit 8f50f16ff39dd4e2d43d1548ca66925652f8aff7 upstream.

Add coverage to the verifier tests and tests for reading bpf_sock fields to
ensure that 32-bit, 16-bit, and 8-bit loads from dst_port field are allowed
only at intended offsets and produce expected values.

While 16-bit and 8-bit access to dst_port field is straight-forward, 32-bit
wide loads need be allowed and produce a zero-padded 16-bit value for
backward compatibility.

Signed-off-by: Jakub Sitnicki 
Link: https://lore.kernel.org/r/20220130115518.213259-3-jakub@cloudflare.com
Signed-off-by: Alexei Starovoitov 
[OP: backport to 5.4: cherry-pick verifier changes only]
Signed-off-by: Ovidiu Panait 
Signed-off-by: Greg Kroah-Hartman

bpf: Fix comment for helper bpf_current_task_under_cgroup()

2022-04-15T12:18:30+00:00

commit 58617014405ad5c9f94f464444f4972dabb71ca7 upstream.

Fix the descriptions of the return values of helper bpf_current_task_under_cgroup().

Fixes: c6b5fb8690fa ("bpf: add documentation for eBPF helpers (42-50)")
Signed-off-by: Hengqi Chen 
Signed-off-by: Daniel Borkmann 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20220310155335.1278783-1-hengqi.chen@gmail.com
Signed-off-by: Greg Kroah-Hartman

tools/nolibc: fix incorrect truncation of exit code

2022-01-27T08:19:27+00:00

commit de0244ae40ae91145faaf164a4252347607c3711 upstream.

Ammar Faizi reported that our exit code handling is wrong. We truncate
it to the lowest 8 bits but the syscall itself is expected to take a
regular 32-bit signed integer, not an unsigned char. It's the kernel
that later truncates it to the lowest 8 bits. The difference is visible
in strace, where the program below used to show exit(255) instead of
exit(-1):

  int main(void)
  {
        return -1;
  }

This patch applies the fix to all archs. x86_64, i386, arm64, armv7 and
mips were all tested and confirmed to work fine now. Risc-v was not
tested but the change is trivial and exactly the same as for other archs.

Reported-by: Ammar Faizi 
Cc: stable@vger.kernel.org
Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney 
Signed-off-by: Greg Kroah-Hartman

tools/nolibc: i386: fix initial stack alignment

2022-01-27T08:19:27+00:00

commit ebbe0d8a449d183fa43b42d84fcb248e25303985 upstream.

After re-checking in the spec and comparing stack offsets with glibc,
The last pushed argument must be 16-byte aligned (i.e. aligned before the
call) so that in the callee esp+4 is multiple of 16, so the principle is
the 32-bit equivalent to what Ammar fixed for x86_64. It's possible that
32-bit code using SSE2 or MMX could have been affected. In addition the
frame pointer ought to be zero at the deepest level.

Link: https://gitlab.com/x86-psABIs/i386-ABI/-/wikis/Intel386-psABI
Cc: Ammar Faizi 
Cc: stable@vger.kernel.org
Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney 
Signed-off-by: Greg Kroah-Hartman