linux-stable.git/tools/include, branch v6.1.78

bpf: Add crosstask check to __bpf_get_stack

2024-01-25T23:27:24+00:00

[ Upstream commit b8e3a87a627b575896e448021e5c2f8a3bc19931 ]

Currently get_perf_callchain only supports user stack walking for
the current task. Passing the correct *crosstask* param will return
0 frames if the task passed to __bpf_get_stack isn't the current
one instead of a single incorrect frame/address. This change
passes the correct *crosstask* param but also does a preemptive
check in __bpf_get_stack if the task is current and returns
-EOPNOTSUPP if it is not.

This issue was found using bpf_get_task_stack inside a BPF
iterator ("iter/task"), which iterates over all tasks.
bpf_get_task_stack works fine for fetching kernel stacks
but because get_perf_callchain relies on the caller to know
if the requested *task* is the current one (via *crosstask*)
it was failing in a confusing way.

It might be possible to get user stacks for all tasks utilizing
something like access_process_vm but that requires the bpf
program calling bpf_get_task_stack to be sleepable and would
therefore be a breaking change.

Fixes: fa28dcb82a38 ("bpf: Introduce helper bpf_get_task_stack()")
Signed-off-by: Jordan Rome 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20231108112334.3433136-1-jordalgo@meta.com
Signed-off-by: Sasha Levin

maple_tree: add GFP_KERNEL to allocations in mas_expected_entries()

2023-11-02T08:35:24+00:00

commit 099d7439ce03d0e7bc8f0c3d7878b562f3a48d3d upstream.

Users complained about OOM errors during fork without triggering
compaction.  This can be fixed by modifying the flags used in
mas_expected_entries() so that the compaction will be triggered in low
memory situations.  Since mas_expected_entries() is only used during fork,
the extra argument does not need to be passed through.

Additionally, the two test_maple_tree test cases and one benchmark test
were altered to use the correct locking type so that allocations would not
trigger sleeping and thus fail.  Testing was completed with lockdep atomic
sleep detection.

The additional locking change requires rwsem support additions to the
tools/ directory through the use of pthreads pthread_rwlock_t.  With this
change test_maple_tree works in userspace, as a module, and in-kernel.

Users may notice that the system gave up early on attempting to start new
processes instead of attempting to reclaim memory.

Link: https://lkml.kernel.org/r/20230915093243epcms1p46fa00bbac1ab7b7dca94acb66c44c456@epcms1p4
Link: https://lkml.kernel.org/r/20231012155233.2272446-1-Liam.Howlett@oracle.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett 
Reviewed-by: Peng Zhang 
Cc: 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

bpf: Add BPF_FIB_LOOKUP_SKIP_NEIGH for bpf_fib_lookup

2023-10-10T20:00:42+00:00

[ Upstream commit 31de4105f00d64570139bc5494a201b0bd57349f ]

The bpf_fib_lookup() also looks up the neigh table.
This was done before bpf_redirect_neigh() was added.

In the use case that does not manage the neigh table
and requires bpf_fib_lookup() to lookup a fib to
decide if it needs to redirect or not, the bpf prog can
depend only on using bpf_redirect_neigh() to lookup the
neigh. It also keeps the neigh entries fresh and connected.

This patch adds a bpf_fib_lookup flag, SKIP_NEIGH, to avoid
the double neigh lookup when the bpf prog always call
bpf_redirect_neigh() to do the neigh lookup. The params->smac
output is skipped together when SKIP_NEIGH is set because
bpf_redirect_neigh() will figure out the smac also.

Signed-off-by: Martin KaFai Lau 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20230217205515.3583372-1-martin.lau@linux.dev
Stable-dep-of: 5baa0433a15e ("neighbour: fix data-races around n->output")
Signed-off-by: Sasha Levin

bpf: Fix BTF_ID symbol generation collision in tools/

2023-10-06T12:57:04+00:00

commit c0bb9fb0e52a64601d38b3739b729d9138d4c8a1 upstream.

Marcus and Satya reported an issue where BTF_ID macro generates same
symbol in separate objects and that breaks final vmlinux link.

  ld.lld: error: ld-temp.o :14577:1: symbol
  '__BTF_ID__struct__cgroup__624' is already defined

This can be triggered under specific configs when __COUNTER__ happens to
be the same for the same symbol in two different translation units,
which is already quite unlikely to happen.

Add __LINE__ number suffix to make BTF_ID symbol more unique, which is
not a complete fix, but it would help for now and meanwhile we can work
on better solution as suggested by Andrii.

Cc: stable@vger.kernel.org
Reported-by: Satya Durga Srinivasu Prabhala 
Reported-by: Marcus Seyfarth 
Closes: https://github.com/ClangBuiltLinux/linux/issues/1913
Debugged-by: Nathan Chancellor 
Co-developed-by: Jiri Olsa 
Link: https://lore.kernel.org/bpf/CAEf4Bzb5KQ2_LmhN769ifMeSJaWfebccUasQOfQKaOd0nQ51tw@mail.gmail.com/
Signed-off-by: Nick Desaulniers 
Link: https://lore.kernel.org/r/20230915-bpf_collision-v3-2-263fc519c21f@google.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Greg Kroah-Hartman

memblock tests: fix warning ‘struct seq_file’ declared inside parameter list

2023-10-06T12:56:56+00:00

[ Upstream commit 55122e0130e51eb71f5ec62d10525db0468f28e8 ]

Building memblock tests produces the following warning:

cc -I. -I../../include -Wall -O2 -fsanitize=address -fsanitize=undefined -D CONFIG_PHYS_ADDR_T_64BIT   -c -o main.o main.c
In file included from tests/common.h:9,
                 from tests/basic_api.h:5,
                 from main.c:2:
./linux/memblock.h:601:50: warning: ‘struct seq_file’ declared inside parameter list will not be visible outside of this definition or declaration
  601 | static inline void memtest_report_meminfo(struct seq_file *m) { }
      |                                                  ^~~~~~~~

Add declaration of 'struct seq_file' to tools/include/linux/seq_file.h
to fix it.

Signed-off-by: Mike Rapoport (IBM) 
Signed-off-by: Sasha Levin

memblock tests: fix warning: "__ALIGN_KERNEL" redefined

2023-10-06T12:56:56+00:00

[ Upstream commit 5e1bffbdb63baf89f3bf0b6bafb50903432a7434 ]

Building memblock tests produces the following warning:

cc -I. -I../../include -Wall -O2 -fsanitize=address -fsanitize=undefined -D CONFIG_PHYS_ADDR_T_64BIT   -c -o main.o main.c
In file included from ../../include/linux/pfn.h:5,
                 from ./linux/memory_hotplug.h:6,
                 from ./linux/init.h:7,
                 from ./linux/memblock.h:11,
                 from tests/common.h:8,
                 from tests/basic_api.h:5,
                 from main.c:2:
../../include/linux/mm.h:14: warning: "__ALIGN_KERNEL" redefined
   14 | #define __ALIGN_KERNEL(x, a)            __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
      |
In file included from ../../include/linux/mm.h:6,
                 from ../../include/linux/pfn.h:5,
                 from ./linux/memory_hotplug.h:6,
                 from ./linux/init.h:7,
                 from ./linux/memblock.h:11,
                 from tests/common.h:8,
                 from tests/basic_api.h:5,
                 from main.c:2:
../../include/uapi/linux/const.h:31: note: this is the location of the previous definition
   31 | #define __ALIGN_KERNEL(x, a)            __ALIGN_KERNEL_MASK(x, (__typeof__(x))(a) - 1)
      |

Remove definitions of __ALIGN_KERNEL and __ALIGN_KERNEL_MASK from
tools/include/linux/mm.h to fix it.

Signed-off-by: Mike Rapoport (IBM) 
Signed-off-by: Sasha Levin

bpf: Clarify error expectations from bpf_clone_redirect

2023-10-06T12:56:55+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 headers UAPI: Sync the linux/in.h with the kernel sources

2023-06-05T07:26:22+00:00

commit 5d1ac59ff7445e51a0e4958fa39ac8aa23691698 upstream.

Picking the changes from:

  91d0b78c5177f3e4 ("inet: Add IP_LOCAL_PORT_RANGE socket option")

Silencing these perf build warnings:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/in.h' differs from latest version at 'include/uapi/linux/in.h'
  diff -u tools/include/uapi/linux/in.h include/uapi/linux/in.h

Signed-off-by: Yanteng Si 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: loongson-kernel@lists.loongnix.cn
Link: https://lore.kernel.org/r/23aabc69956ac94fbf388b05c8be08a64e8c7ccc.1683712945.git.siyanteng@loongson.cn
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

open: return EINVAL for O_DIRECTORY | O_CREAT

2023-05-24T16:32:34+00:00

[ Upstream commit 43b450632676fb60e9faeddff285d9fac94a4f58 ]

After a couple of years and multiple LTS releases we received a report
that the behavior of O_DIRECTORY | O_CREAT changed starting with v5.7.

On kernels prior to v5.7 combinations of O_DIRECTORY, O_CREAT, O_EXCL
had the following semantics:

(1) open("/tmp/d", O_DIRECTORY | O_CREAT)
    * d doesn't exist:                create regular file
    * d exists and is a regular file: ENOTDIR
    * d exists and is a directory:    EISDIR

(2) open("/tmp/d", O_DIRECTORY | O_CREAT | O_EXCL)
    * d doesn't exist:                create regular file
    * d exists and is a regular file: EEXIST
    * d exists and is a directory:    EEXIST

(3) open("/tmp/d", O_DIRECTORY | O_EXCL)
    * d doesn't exist:                ENOENT
    * d exists and is a regular file: ENOTDIR
    * d exists and is a directory:    open directory

On kernels since to v5.7 combinations of O_DIRECTORY, O_CREAT, O_EXCL
have the following semantics:

(1) open("/tmp/d", O_DIRECTORY | O_CREAT)
    * d doesn't exist:                ENOTDIR (create regular file)
    * d exists and is a regular file: ENOTDIR
    * d exists and is a directory:    EISDIR

(2) open("/tmp/d", O_DIRECTORY | O_CREAT | O_EXCL)
    * d doesn't exist:                ENOTDIR (create regular file)
    * d exists and is a regular file: EEXIST
    * d exists and is a directory:    EEXIST

(3) open("/tmp/d", O_DIRECTORY | O_EXCL)
    * d doesn't exist:                ENOENT
    * d exists and is a regular file: ENOTDIR
    * d exists and is a directory:    open directory

This is a fairly substantial semantic change that userspace didn't
notice until Pedro took the time to deliberately figure out corner
cases. Since no one noticed this breakage we can somewhat safely assume
that O_DIRECTORY | O_CREAT combinations are likely unused.

The v5.7 breakage is especially weird because while ENOTDIR is returned
indicating failure a regular file is actually created. This doesn't make
a lot of sense.

Time was spent finding potential users of this combination. Searching on
codesearch.debian.net showed that codebases often express semantical
expectations about O_DIRECTORY | O_CREAT which are completely contrary
to what our code has done and currently does.

The expectation often is that this particular combination would create
and open a directory. This suggests users who tried to use that
combination would stumble upon the counterintuitive behavior no matter
if pre-v5.7 or post v5.7 and quickly realize neither semantics give them
what they want. For some examples see the code examples in [1] to [3]
and the discussion in [4].

There are various ways to address this issue. The lazy/simple option
would be to restore the pre-v5.7 behavior and to just live with that bug
forever. But since there's a real chance that the O_DIRECTORY | O_CREAT
quirk isn't relied upon we should try to get away with murder(ing bad
semantics) first. If we need to Frankenstein pre-v5.7 behavior later so
be it.

So let's simply return EINVAL categorically for O_DIRECTORY | O_CREAT
combinations. In addition to cleaning up the old bug this also opens up
the possiblity to make that flag combination do something more intuitive
in the future.

Starting with this commit the following semantics apply:

(1) open("/tmp/d", O_DIRECTORY | O_CREAT)
    * d doesn't exist:                EINVAL
    * d exists and is a regular file: EINVAL
    * d exists and is a directory:    EINVAL

(2) open("/tmp/d", O_DIRECTORY | O_CREAT | O_EXCL)
    * d doesn't exist:                EINVAL
    * d exists and is a regular file: EINVAL
    * d exists and is a directory:    EINVAL

(3) open("/tmp/d", O_DIRECTORY | O_EXCL)
    * d doesn't exist:                ENOENT
    * d exists and is a regular file: ENOTDIR
    * d exists and is a directory:    open directory

One additional note, O_TMPFILE is implemented as:

    #define __O_TMPFILE    020000000
    #define O_TMPFILE      (__O_TMPFILE | O_DIRECTORY)
    #define O_TMPFILE_MASK (__O_TMPFILE | O_DIRECTORY | O_CREAT)

For older kernels it was important to return an explicit error when
O_TMPFILE wasn't supported. So O_TMPFILE requires that O_DIRECTORY is
raised alongside __O_TMPFILE. It also enforced that O_CREAT wasn't
specified. Since O_DIRECTORY | O_CREAT could be used to create a regular
allowing that combination together with __O_TMPFILE would've meant that
false positives were possible, i.e., that a regular file was created
instead of a O_TMPFILE. This could've been used to trick userspace into
thinking it operated on a O_TMPFILE when it wasn't.

Now that we block O_DIRECTORY | O_CREAT completely the check for O_CREAT
in the __O_TMPFILE branch via if ((flags & O_TMPFILE_MASK) != O_TMPFILE)
can be dropped. Instead we can simply check verify that O_DIRECTORY is
raised via if (!(flags & O_DIRECTORY)) and explain this in two comments.

As Aleksa pointed out O_PATH is unaffected by this change since it
always returned EINVAL if O_CREAT was specified - with or without
O_DIRECTORY.

Link: https://lore.kernel.org/lkml/20230320071442.172228-1-pedro.falcato@gmail.com
Link: https://sources.debian.org/src/flatpak/1.14.4-1/subprojects/libglnx/glnx-dirfd.c/?hl=324#L324 [1]
Link: https://sources.debian.org/src/flatpak-builder/1.2.3-1/subprojects/libglnx/glnx-shutil.c/?hl=251#L251 [2]
Link: https://sources.debian.org/src/ostree/2022.7-2/libglnx/glnx-dirfd.c/?hl=324#L324 [3]
Link: https://www.openwall.com/lists/oss-security/2014/11/26/14 [4]
Reported-by: Pedro Falcato 
Cc: Aleksa Sarai 
Signed-off-by: Linus Torvalds 
Signed-off-by: Christian Brauner 
Signed-off-by: Sasha Levin

tools/nolibc: prevent gcc from making memset() loop over itself

2023-02-01T07:34:31+00:00

[ Upstream commit 1bfbe1f3e96720daf185f03d101f072d69753f88 ]

When building on ARM in thumb mode with gcc-11.3 at -O2 or -O3,
nolibc-test segfaults during the select() tests. It turns out that at
this level, gcc recognizes an opportunity for using memset() to zero
the fd_set, but it miscompiles it because it also recognizes a memset
pattern as well, and decides to call memset() from the memset() code:

  000122bc :
     122bc:       b510            push    {r4, lr}
     122be:       0004            movs    r4, r0
     122c0:       2a00            cmp     r2, #0
     122c2:       d003            beq.n   122cc 
     122c4:       23ff            movs    r3, #255        ; 0xff
     122c6:       4019            ands    r1, r3
     122c8:       f7ff fff8       bl      122bc 
     122cc:       0020            movs    r0, r4
     122ce:       bd10            pop     {r4, pc}

Simply placing an empty asm() statement inside the loop suffices to
avoid this.

Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney 
Signed-off-by: Sasha Levin