linux.git/tools/include, branch v6.6.23

tools/resolve_btfids: Refactor set sorting with types from btf_ids.h

2024-03-26T22:19:27+00:00

[ Upstream commit 9707ac4fe2f5bac6406d2403f8b8a64d7b3d8e43 ]

Instead of using magic offsets to access BTF ID set data, leverage types
from btf_ids.h (btf_id_set and btf_id_set8) which define the actual
layout of the data. Thanks to this change, set sorting should also
continue working if the layout changes.

This requires to sync the definition of 'struct btf_id_set8' from
include/linux/btf_ids.h to tools/include/linux/btf_ids.h. We don't sync
the rest of the file at the moment, b/c that would require to also sync
multiple dependent headers and we don't need any other defs from
btf_ids.h.

Signed-off-by: Viktor Malik 
Signed-off-by: Andrii Nakryiko 
Acked-by: Daniel Xu 
Link: https://lore.kernel.org/bpf/ff7f062ddf6a00815fda3087957c4ce667f50532.1707223196.git.vmalik@redhat.com
Stable-dep-of: 903fad439466 ("tools/resolve_btfids: Fix cross-compilation to non-host endianness")
Signed-off-by: Sasha Levin

bpf: Derive source IP addr via bpf_*_fib_lookup()

2024-03-01T12:35:04+00:00

commit dab4e1f06cabb6834de14264394ccab197007302 upstream.

Extend the bpf_fib_lookup() helper by making it to return the source
IPv4/IPv6 address if the BPF_FIB_LOOKUP_SRC flag is set.

For example, the following snippet can be used to derive the desired
source IP address:

    struct bpf_fib_lookup p = { .ipv4_dst = ip4->daddr };

    ret = bpf_skb_fib_lookup(skb, p, sizeof(p),
            BPF_FIB_LOOKUP_SRC | BPF_FIB_LOOKUP_SKIP_NEIGH);
    if (ret != BPF_FIB_LKUP_RET_SUCCESS)
        return TC_ACT_SHOT;

    /* the p.ipv4_src now contains the source address */

The inability to derive the proper source address may cause malfunctions
in BPF-based dataplanes for hosts containing netdevs with more than one
routable IP address or for multi-homed hosts.

For example, Cilium implements packet masquerading in BPF. If an
egressing netdev to which the Cilium's BPF prog is attached has
multiple IP addresses, then only one [hardcoded] IP address can be used for
masquerading. This breaks connectivity if any other IP address should have
been selected instead, for example, when a public and private addresses
are attached to the same egress interface.

The change was tested with Cilium [1].

Nikolay Aleksandrov helped to figure out the IPv6 addr selection.

[1]: https://github.com/cilium/cilium/pull/28283

Signed-off-by: Martynas Pumputis 
Link: https://lore.kernel.org/r/20231007081415.33502-2-m@lambda.lt
Signed-off-by: Martin KaFai Lau 
Cc: Daniel Borkmann 
Signed-off-by: Greg Kroah-Hartman

work around gcc bugs with 'asm goto' with outputs

2024-02-23T08:24:47+00:00

commit 4356e9f841f7fbb945521cef3577ba394c65f3fc upstream.

We've had issues with gcc and 'asm goto' before, and we created a
'asm_volatile_goto()' macro for that in the past: see commits
3f0116c3238a ("compiler/gcc4: Add quirk for 'asm goto' miscompilation
bug") and a9f180345f53 ("compiler/gcc4: Make quirk for
asm_volatile_goto() unconditional").

Then, much later, we ended up removing the workaround in commit
43c249ea0b1e ("compiler-gcc.h: remove ancient workaround for gcc PR
58670") because we no longer supported building the kernel with the
affected gcc versions, but we left the macro uses around.

Now, Sean Christopherson reports a new version of a very similar
problem, which is fixed by re-applying that ancient workaround.  But the
problem in question is limited to only the 'asm goto with outputs'
cases, so instead of re-introducing the old workaround as-is, let's
rename and limit the workaround to just that much less common case.

It looks like there are at least two separate issues that all hit in
this area:

 (a) some versions of gcc don't mark the asm goto as 'volatile' when it
     has outputs:

        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619
        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420

     which is easy to work around by just adding the 'volatile' by hand.

 (b) Internal compiler errors:

        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422

     which are worked around by adding the extra empty 'asm' as a
     barrier, as in the original workaround.

but the problem Sean sees may be a third thing since it involves bad
code generation (not an ICE) even with the manually added 'volatile'.

but the same old workaround works for this case, even if this feels a
bit like voodoo programming and may only be hiding the issue.

Reported-and-tested-by: Sean Christopherson 
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers 
Cc: Uros Bizjak 
Cc: Jakub Jelinek 
Cc: Andrew Pinski 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

bpf: Add crosstask check to __bpf_get_stack

2024-01-25T23:35:19+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

mm: add a NO_INHERIT flag to the PR_SET_MDWE prctl

2023-12-03T06:33:06+00:00

[ Upstream commit 24e41bf8a6b424c76c5902fb999e9eca61bdf83d ]

This extends the current PR_SET_MDWE prctl arg with a bit to indicate that
the process doesn't want MDWE protection to propagate to children.

To implement this no-inherit mode, the tag in current->mm->flags must be
absent from MMF_INIT_MASK.  This means that the encoding for "MDWE but
without inherit" is different in the prctl than in the mm flags.  This
leads to a bit of bit-mangling in the prctl implementation.

Link: https://lkml.kernel.org/r/20230828150858.393570-6-revest@chromium.org
Signed-off-by: Florent Revest 
Reviewed-by: Kees Cook 
Reviewed-by: Catalin Marinas 
Cc: Alexey Izbyshev 
Cc: Anshuman Khandual 
Cc: Ayush Jain 
Cc: David Hildenbrand 
Cc: Greg Thelen 
Cc: Joey Gouly 
Cc: KP Singh 
Cc: Mark Brown 
Cc: Michal Hocko 
Cc: Peter Xu 
Cc: Ryan Roberts 
Cc: Szabolcs Nagy 
Cc: Topi Miettinen 
Signed-off-by: Andrew Morton 
Stable-dep-of: 793838138c15 ("prctl: Disable prctl(PR_SET_MDWE) on parisc")
Signed-off-by: Sasha Levin

mm: make PR_MDWE_REFUSE_EXEC_GAIN an unsigned long

2023-11-28T17:20:06+00:00

commit 0da668333fb07805c2836d5d50e26eda915b24a1 upstream.

Defining a prctl flag as an int is a footgun because on a 64 bit machine
and with a variadic implementation of prctl (like in musl and glibc), when
used directly as a prctl argument, it can get casted to long with garbage
upper bits which would result in unexpected behaviors.

This patch changes the constant to an unsigned long to eliminate that
possibilities.  This does not break UAPI.

I think that a stable backport would be "nice to have": to reduce the
chances that users build binaries that could end up with garbage bits in
their MDWE prctl arguments.  We are not aware of anyone having yet
encountered this corner case with MDWE prctls but a backport would reduce
the likelihood it happens, since this sort of issues has happened with
other prctls.  But If this is perceived as a backporting burden, I suppose
we could also live without a stable backport.

Link: https://lkml.kernel.org/r/20230828150858.393570-5-revest@chromium.org
Fixes: b507808ebce2 ("mm: implement memory-deny-write-execute as a prctl")
Signed-off-by: Florent Revest 
Suggested-by: Alexey Izbyshev 
Reviewed-by: David Hildenbrand 
Reviewed-by: Kees Cook 
Acked-by: Catalin Marinas 
Cc: Anshuman Khandual 
Cc: Ayush Jain 
Cc: Greg Thelen 
Cc: Joey Gouly 
Cc: KP Singh 
Cc: Mark Brown 
Cc: Michal Hocko 
Cc: Peter Xu 
Cc: Ryan Roberts 
Cc: Szabolcs Nagy 
Cc: Topi Miettinen 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'mm-hotfixes-stable-2023-10-24-09-40' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-10-24T19:52:16+00:00

Pull misc fixes from Andrew Morton:
 "20 hotfixes. 12 are cc:stable and the remainder address post-6.5
  issues or aren't considered necessary for earlier kernel versions"

* tag 'mm-hotfixes-stable-2023-10-24-09-40' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  maple_tree: add GFP_KERNEL to allocations in mas_expected_entries()
  selftests/mm: include mman header to access MREMAP_DONTUNMAP identifier
  mailmap: correct email aliasing for Oleksij Rempel
  mailmap: map Bartosz's old address to the current one
  mm/damon/sysfs: check DAMOS regions update progress from before_terminate()
  MAINTAINERS: Ondrej has moved
  kasan: disable kasan_non_canonical_hook() for HW tags
  kasan: print the original fault addr when access invalid shadow
  hugetlbfs: close race between MADV_DONTNEED and page fault
  hugetlbfs: extend hugetlb_vma_lock to private VMAs
  hugetlbfs: clear resv_map pointer if mmap fails
  mm: zswap: fix pool refcount bug around shrink_worker()
  mm/migrate: fix do_pages_move for compat pointers
  riscv: fix set_huge_pte_at() for NAPOT mappings when a swap entry is set
  riscv: handle VM_FAULT_[HWPOISON|HWPOISON_LARGE] faults instead of panicking
  mmap: fix error paths with dup_anon_vma()
  mmap: fix vma_iterator in error path of vma_merge()
  mm: fix vm_brk_flags() to not bail out while holding lock
  mm/mempolicy: fix set_mempolicy_home_node() previous VMA pointer
  mm/page_alloc: correct start page when guard page debug is enabled

Merge tag 'urgent/nolibc.2023.10.16a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

2023-10-24T00:19:11+00:00

Pull nolibc fixes from Paul McKenney:

 - tools/nolibc: i386: Fix a stack misalign bug on _start

 - MAINTAINERS: nolibc: update tree location

 - tools/nolibc: mark start_c as weak to avoid linker errors

* tag 'urgent/nolibc.2023.10.16a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  tools/nolibc: mark start_c as weak
  MAINTAINERS: nolibc: update tree location
  tools/nolibc: i386: Fix a stack misalign bug on _start

maple_tree: add GFP_KERNEL to allocations in mas_expected_entries()

2023-10-18T19:12:41+00:00

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

tools/nolibc: mark start_c as weak

2023-10-12T19:13:51+00:00

Otherwise the different instances of _start_c from each compilation unit
will lead to linker errors:

/usr/bin/ld: /tmp/ccSNvRqs.o: in function `_start_c':
nolibc-test-foo.c:(.text.nolibc_memset+0x9): multiple definition of `_start_c'; /tmp/ccG25101.o:nolibc-test.c:(.text+0x1ea3): first defined here

Fixes: 17336755150b ("tools/nolibc: add new crt.h with _start_c")
Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/lkml/20231012-nolibc-start_c-multiple-v1-1-fbfc73e0283f@weissschuh.net/
Link: https://lore.kernel.org/lkml/20231012-nolibc-linkage-test-v1-1-315e682768b4@weissschuh.net/
Acked-by: Willy Tarreau