Commit Graph

1846 Commits

Author SHA1 Message Date
Wei Yang
85e4923bcb memblock tests: fix implicit declaration of function 'numa_valid_node'
commit 9364a7e40d54e6858479f0a96e1a04aa1204be16 upstream.

commit 8043832e2a12 ("memblock: use numa_valid_node() helper to check
for invalid node ID") introduce a new helper numa_valid_node(), which is
not defined in memblock tests.

Let's add it in the corresponding header file.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Mike Rapoport (IBM) <rppt@kernel.org>
Link: https://lore.kernel.org/r/20240624015432.31134-1-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17 13:36:14 +01:00
Alexander Lobakin
23681bc4b5 stddef: make __struct_group() UAPI C++-friendly
[ Upstream commit 724c6ce38bbaeb4b3f109b0e066d6c0ecd15446c ]

For the most part of the C++ history, it couldn't have type
declarations inside anonymous unions for different reasons. At the
same time, __struct_group() relies on the latters, so when the @TAG
argument is not empty, C++ code doesn't want to build (even under
`extern "C"`):

../linux/include/uapi/linux/pkt_cls.h:25:24: error:
'struct tc_u32_sel::<unnamed union>::tc_u32_sel_hdr,' invalid;
an anonymous union may only have public non-static data members
[-fpermissive]

The safest way to fix this without trying to switch standards (which
is impossible in UAPI anyway) etc., is to disable tag declaration
for that language. This won't break anything since for now it's not
buildable at all.
Use a separate definition for __struct_group() when __cplusplus is
defined to mitigate the error, including the version from tools/.

Fixes: 50d7bd38c3 ("stddef: Introduce struct_group() helper macro")
Reported-by: Christopher Ferris <cferris@google.com>
Closes: https://lore.kernel.org/linux-hardening/Z1HZpe3WE5As8UAz@google.com
Suggested-by: Kees Cook <kees@kernel.org> # __struct_group_tag()
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20241219135734.2130002-1-aleksander.lobakin@intel.com
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-02 10:32:03 +01:00
Thomas Weißschuh
ee68555b97 tools/nolibc: s390: include std.h
commit 711b5875814b2a0e9a5aaf7a85ba7c80f5a389b1 upstream.

arch-s390.h uses types from std.h, but does not include it.
Depending on the inclusion order the compilation can fail.
Include std.h explicitly to avoid these errors.

Fixes: 404fa87c0e ("tools/nolibc: s390: provide custom implementation for sys_fork")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://lore.kernel.org/r/20240927-nolibc-s390-std-h-v1-1-30442339a6b9@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-09 10:32:45 +01:00
Jiri Olsa
cfd63c3a45 bpf: Add cookie to perf_event bpf_link_info records
[ Upstream commit d5c16492c66fbfca85f36e42363d32212df5927b ]

At the moment we don't store cookie for perf_event probes,
while we do that for the rest of the probes.

Adding cookie fields to struct bpf_link_info perf event
probe records:

  perf_event.uprobe
  perf_event.kprobe
  perf_event.tracepoint
  perf_event.perf_event

And the code to store that in bpf_link_info struct.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20240119110505.400573-2-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: 4deecdd29cf2 ("bpf: fix unpopulated name_len field in perf_event link info")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-01 01:58:19 +01:00
Jiri Olsa
99bf10e92a bpf: Add missed value to kprobe perf link info
[ Upstream commit 3acf8ace68230e9558cf916847f1cc9f208abdf1 ]

Add missed value to kprobe attached through perf link info to
hold the stats of missed kprobe handler execution.

The kprobe's missed counter gets incremented when kprobe handler
is not executed due to another kprobe running on the same cpu.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230920213145.1941596-4-jolsa@kernel.org
Stable-dep-of: 4deecdd29cf2 ("bpf: fix unpopulated name_len field in perf_event link info")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-01 01:58:19 +01:00
Thomas Weißschuh
fc975b8dab tools/nolibc: powerpc: limit stack-protector workaround to GCC
[ Upstream commit 1daea158d0aae0770371f3079305a29fdb66829e ]

As mentioned in the comment, the workaround for
__attribute__((no_stack_protector)) is only necessary on GCC.
Avoid applying the workaround on clang, as clang does not recognize
__attribute__((__optimize__)) and would fail.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20240807-nolibc-llvm-v2-3-c20f2f5fc7c2@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-10 11:57:30 +02:00
Alexander Lobakin
a2081b8cab tools: move alignment-related macros to new <linux/align.h>
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
<linux/align.h> inside the tools/ folder and include it where needed.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-29 17:33:59 +02:00
Alexander Lobakin
97a532c3ac bitmap: introduce generic optimized bitmap_size()
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 <przemyslaw.kitszel@intel.com>
Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-29 17:33:14 +02:00
Kees Cook
ef33f02968 bpf: Replace bpf_lpm_trie_key 0-length array with flexible array
[ Upstream commit 896880ff30866f386ebed14ab81ce1ad3710cfc4 ]

Replace deprecated 0-length array in struct bpf_lpm_trie_key with
flexible array. Found with GCC 13:

../kernel/bpf/lpm_trie.c:207:51: warning: array subscript i is outside array bounds of 'const __u8[0]' {aka 'const unsigned char[]'} [-Warray-bounds=]
  207 |                                        *(__be16 *)&key->data[i]);
      |                                                   ^~~~~~~~~~~~~
../include/uapi/linux/swab.h:102:54: note: in definition of macro '__swab16'
  102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
      |                                                      ^
../include/linux/byteorder/generic.h:97:21: note: in expansion of macro '__be16_to_cpu'
   97 | #define be16_to_cpu __be16_to_cpu
      |                     ^~~~~~~~~~~~~
../kernel/bpf/lpm_trie.c:206:28: note: in expansion of macro 'be16_to_cpu'
  206 |                 u16 diff = be16_to_cpu(*(__be16 *)&node->data[i]
^
      |                            ^~~~~~~~~~~
In file included from ../include/linux/bpf.h:7:
../include/uapi/linux/bpf.h:82:17: note: while referencing 'data'
   82 |         __u8    data[0];        /* Arbitrary size */
      |                 ^~~~

And found at run-time under CONFIG_FORTIFY_SOURCE:

  UBSAN: array-index-out-of-bounds in kernel/bpf/lpm_trie.c:218:49
  index 0 is out of range for type '__u8 [*]'

Changing struct bpf_lpm_trie_key is difficult since has been used by
userspace. For example, in Cilium:

	struct egress_gw_policy_key {
	        struct bpf_lpm_trie_key lpm_key;
	        __u32 saddr;
	        __u32 daddr;
	};

While direct references to the "data" member haven't been found, there
are static initializers what include the final member. For example,
the "{}" here:

        struct egress_gw_policy_key in_key = {
                .lpm_key = { 32 + 24, {} },
                .saddr   = CLIENT_IP,
                .daddr   = EXTERNAL_SVC_IP & 0Xffffff,
        };

To avoid the build time and run time warnings seen with a 0-sized
trailing array for struct bpf_lpm_trie_key, introduce a new struct
that correctly uses a flexible array for the trailing bytes,
struct bpf_lpm_trie_key_u8. As part of this, include the "header"
portion (which is just the "prefixlen" member), so it can be used
by anything building a bpf_lpr_trie_key that has trailing members that
aren't a u8 flexible array (like the self-test[1]), which is named
struct bpf_lpm_trie_key_hdr.

Unfortunately, C++ refuses to parse the __struct_group() helper, so
it is not possible to define struct bpf_lpm_trie_key_hdr directly in
struct bpf_lpm_trie_key_u8, so we must open-code the union directly.

Adjust the kernel code to use struct bpf_lpm_trie_key_u8 through-out,
and for the selftest to use struct bpf_lpm_trie_key_hdr. Add a comment
to the UAPI header directing folks to the two new options.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Closes: https://paste.debian.net/hidden/ca500597/
Link: https://lore.kernel.org/all/202206281009.4332AA33@keescook/ [1]
Link: https://lore.kernel.org/bpf/20240222155612.it.533-kees@kernel.org
Stable-dep-of: 59f2f841179a ("bpf: Avoid kfree_rcu() under lock in bpf_lpm_trie.")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-19 06:04:27 +02:00
Anton Protopopov
7a7d4237e3 bpf: Pack struct bpf_fib_lookup
[ Upstream commit f91717007217d975aa975ddabd91ae1a107b9bff ]

The struct bpf_fib_lookup is supposed to be of size 64. A recent commit
59b418c7063d ("bpf: Add a check for struct bpf_fib_lookup size") added
a static assertion to check this property so that future changes to the
structure will not accidentally break this assumption.

As it immediately turned out, on some 32-bit arm systems, when AEABI=n,
the total size of the structure was equal to 68, see [1]. This happened
because the bpf_fib_lookup structure contains a union of two 16-bit
fields:

    union {
            __u16 tot_len;
            __u16 mtu_result;
    };

which was supposed to compile to a 16-bit-aligned 16-bit field. On the
aforementioned setups it was instead both aligned and padded to 32-bits.

Declare this inner union as __attribute__((packed, aligned(2))) such
that it always is of size 2 and is aligned to 16 bits.

  [1] https://lore.kernel.org/all/CA+G9fYtsoP51f-oP_Sp5MOq-Ffv8La2RztNpwvE6+R1VtFiLrw@mail.gmail.com/#t

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Fixes: e1850ea9bd ("bpf: bpf_fib_lookup return MTU value as output when looked up")
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240403123303.1452184-1-aspsk@isovalent.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:11:38 +02:00
Brennan Xavier McManus
f678c3c336 tools/nolibc/stdlib: fix memory error in realloc()
commit 791f4641142e2aced85de082e5783b4fb0b977c2 upstream.

Pass user_p_len to memcpy() instead of heap->len to prevent realloc()
from copying an extra sizeof(heap) bytes from beyond the allocated
region.

Signed-off-by: Brennan Xavier McManus <bxmcmanus@gmail.com>
Cc: stable@vger.kernel.org
Reviewed-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Fixes: 0e0ff63840 ("tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`")
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-12 11:11:19 +02:00
Wei Yang
85907602db memblock tests: fix undefined reference to `panic'
[ Upstream commit e0f5a8e74be88f2476e58b25d3b49a9521bdc4ec ]

commit e96c6b8f212a ("memblock: report failures when memblock_can_resize
is not set") introduced the usage of panic, which is not defined in
memblock test.

Let's define it directly in panic.h to fix it.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Song Shuai <songshuaishuai@tinylab.org>
CC: Mike Rapoport <rppt@kernel.org>
Link: https://lore.kernel.org/r/20240402132701.29744-3-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17 12:02:14 +02:00
Wei Yang
63e58e5aef memblock tests: fix undefined reference to `early_pfn_to_nid'
[ Upstream commit 7d8ed162e6a92268d4b2b84d364a931216102c8e ]

commit 6a9531c3a880 ("memblock: fix crash when reserved memory is not
added to memory") introduce the usage of early_pfn_to_nid, which is not
defined in memblock tests.

The original definition of early_pfn_to_nid is defined in mm.h, so let
add this in the corresponding mm.h.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Yajun Deng <yajun.deng@linux.dev>
CC: Mike Rapoport <rppt@kernel.org>
Link: https://lore.kernel.org/r/20240402132701.29744-2-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17 12:02:14 +02:00
Natanael Copa
3a9569441b tools/resolve_btfids: fix build with musl libc
commit 62248b22d01e96a4d669cde0d7005bd51ebf9e76 upstream.

Include the header that defines u32.
This fixes build of 6.6.23 and 6.1.83 kernels for Alpine Linux, which
uses musl libc. I assume that GNU libc indirecly pulls in linux/types.h.

Fixes: 9707ac4fe2f5 ("tools/resolve_btfids: Refactor set sorting with types from btf_ids.h")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218647
Cc: stable@vger.kernel.org
Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Tested-by: Greg Thelen <gthelen@google.com>
Link: https://lore.kernel.org/r/20240328110103.28734-1-ncopa@alpinelinux.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-03 15:29:03 +02:00
Viktor Malik
29d1ee8e7a tools/resolve_btfids: Refactor set sorting with types from btf_ids.h
[ 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 <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Daniel Xu <dxu@dxuuu.xyz>
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 <sashal@kernel.org>
2024-03-26 18:19:27 -04:00
Martynas Pumputis
b96f500dbb bpf: Derive source IP addr via bpf_*_fib_lookup()
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 <m@lambda.lt>
Link: https://lore.kernel.org/r/20231007081415.33502-2-m@lambda.lt
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-01 13:35:04 +01:00
Linus Torvalds
aaff74d886 work around gcc bugs with 'asm goto' with outputs
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
3f0116c323 ("compiler/gcc4: Add quirk for 'asm goto' miscompilation
bug") and a9f180345f ("compiler/gcc4: Make quirk for
asm_volatile_goto() unconditional").

Then, much later, we ended up removing the workaround in commit
43c249ea0b ("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 <seanjc@google.com>
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 09:24:47 +01:00
Jordan Rome
a341738951 bpf: Add crosstask check to __bpf_get_stack
[ 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: fa28dcb82a ("bpf: Introduce helper bpf_get_task_stack()")
Signed-off-by: Jordan Rome <jordalgo@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231108112334.3433136-1-jordalgo@meta.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:35:19 -08:00
Florent Revest
2b00d1fd9a mm: add a NO_INHERIT flag to the PR_SET_MDWE prctl
[ 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 <revest@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexey Izbyshev <izbyshev@ispras.ru>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ayush Jain <ayush.jain3@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Cc: Topi Miettinen <toiwoton@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 793838138c15 ("prctl: Disable prctl(PR_SET_MDWE) on parisc")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-03 07:33:06 +01:00
Florent Revest
2500a33323 mm: make PR_MDWE_REFUSE_EXEC_GAIN an unsigned long
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: b507808ebc ("mm: implement memory-deny-write-execute as a prctl")
Signed-off-by: Florent Revest <revest@chromium.org>
Suggested-by: Alexey Izbyshev <izbyshev@ispras.ru>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ayush Jain <ayush.jain3@amd.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Cc: Topi Miettinen <toiwoton@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:20:06 +00:00
Linus Torvalds
4f82870119 Merge tag 'mm-hotfixes-stable-2023-10-24-09-40' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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
2023-10-24 09:52:16 -10:00
Linus Torvalds
84186fcb83 Merge tag 'urgent/nolibc.2023.10.16a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
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
2023-10-23 14:19:11 -10:00
Liam R. Howlett
099d7439ce maple_tree: add GFP_KERNEL to allocations in mas_expected_entries()
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: 54a611b605 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: <jason.sim@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 12:12:41 -07:00
Thomas Weißschuh
921992229b tools/nolibc: mark start_c as weak
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: 1733675515 ("tools/nolibc: add new crt.h with _start_c")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
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 <w@1wt.eu>
2023-10-12 21:13:51 +02:00
Ammar Faizi
d873a364ef tools/nolibc: i386: Fix a stack misalign bug on _start
The ABI mandates that the %esp register must be a multiple of 16 when
executing a 'call' instruction.

Commit 2ab446336b ("tools/nolibc: i386: shrink _start with _start_c")
simplified the _start function, but it didn't take care of the %esp
alignment, causing SIGSEGV on SSE and AVX programs that use aligned move
instruction (e.g., movdqa, movaps, and vmovdqa).

The 'and $-16, %esp' aligns the %esp at a multiple of 16. Then 'push
%eax' will subtract the %esp by 4; thus, it breaks the 16-byte
alignment. Make sure the %esp is correctly aligned after the push by
subtracting 12 before the push.

Extra:
Add 'add $12, %esp' before the 'and $-16, %esp' to avoid over-estimating
for particular cases as suggested by Willy.

A test program to validate the %esp alignment on _start can be found at:

   https://lore.kernel.org/lkml/ZOoindMFj1UKqo+s@biznet-home.integral.gnuweeb.org

[ Thomas: trim Fixes tag commit id ]

Cc: Zhangjin Wu <falcon@tinylab.org>
Fixes: 2ab446336b ("tools/nolibc: i386: shrink _start with _start_c")
Reported-by: Nicholas Rosenberg <inori@vnlx.org>
Acked-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Reviewed-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2023-10-12 21:10:37 +02:00