<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel/trace/bpf_trace.c, branch v5.19-rc1</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>bpf: Add bpf_skc_to_mptcp_sock_proto</title>
<updated>2022-05-20T22:29:00+00:00</updated>
<author>
<name>Geliang Tang</name>
<email>geliang.tang@suse.com</email>
</author>
<published>2022-05-19T23:30:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3bc253c2e652cf5f12cd8c00d80d8ec55d67d1a7'/>
<id>3bc253c2e652cf5f12cd8c00d80d8ec55d67d1a7</id>
<content type='text'>
This patch implements a new struct bpf_func_proto, named
bpf_skc_to_mptcp_sock_proto. Define a new bpf_id BTF_SOCK_TYPE_MPTCP,
and a new helper bpf_skc_to_mptcp_sock(), which invokes another new
helper bpf_mptcp_sock_from_subflow() in net/mptcp/bpf.c to get struct
mptcp_sock from a given subflow socket.

v2: Emit BTF type, add func_id checks in verifier.c and bpf_trace.c,
remove build check for CONFIG_BPF_JIT
v5: Drop EXPORT_SYMBOL (Martin)

Co-developed-by: Nicolas Rybowski &lt;nicolas.rybowski@tessares.net&gt;
Co-developed-by: Matthieu Baerts &lt;matthieu.baerts@tessares.net&gt;
Signed-off-by: Nicolas Rybowski &lt;nicolas.rybowski@tessares.net&gt;
Signed-off-by: Matthieu Baerts &lt;matthieu.baerts@tessares.net&gt;
Signed-off-by: Geliang Tang &lt;geliang.tang@suse.com&gt;
Signed-off-by: Mat Martineau &lt;mathew.j.martineau@linux.intel.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20220519233016.105670-2-mathew.j.martineau@linux.intel.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch implements a new struct bpf_func_proto, named
bpf_skc_to_mptcp_sock_proto. Define a new bpf_id BTF_SOCK_TYPE_MPTCP,
and a new helper bpf_skc_to_mptcp_sock(), which invokes another new
helper bpf_mptcp_sock_from_subflow() in net/mptcp/bpf.c to get struct
mptcp_sock from a given subflow socket.

v2: Emit BTF type, add func_id checks in verifier.c and bpf_trace.c,
remove build check for CONFIG_BPF_JIT
v5: Drop EXPORT_SYMBOL (Martin)

Co-developed-by: Nicolas Rybowski &lt;nicolas.rybowski@tessares.net&gt;
Co-developed-by: Matthieu Baerts &lt;matthieu.baerts@tessares.net&gt;
Signed-off-by: Nicolas Rybowski &lt;nicolas.rybowski@tessares.net&gt;
Signed-off-by: Matthieu Baerts &lt;matthieu.baerts@tessares.net&gt;
Signed-off-by: Geliang Tang &lt;geliang.tang@suse.com&gt;
Signed-off-by: Mat Martineau &lt;mathew.j.martineau@linux.intel.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20220519233016.105670-2-mathew.j.martineau@linux.intel.com
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: add bpf_map_lookup_percpu_elem for percpu map</title>
<updated>2022-05-12T01:16:54+00:00</updated>
<author>
<name>Feng Zhou</name>
<email>zhoufeng.zf@bytedance.com</email>
</author>
<published>2022-05-11T09:38:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=07343110b293456d30393e89b86c4dee1ac051c8'/>
<id>07343110b293456d30393e89b86c4dee1ac051c8</id>
<content type='text'>
Add new ebpf helpers bpf_map_lookup_percpu_elem.

The implementation method is relatively simple, refer to the implementation
method of map_lookup_elem of percpu map, increase the parameters of cpu, and
obtain it according to the specified cpu.

Signed-off-by: Feng Zhou &lt;zhoufeng.zf@bytedance.com&gt;
Link: https://lore.kernel.org/r/20220511093854.411-2-zhoufeng.zf@bytedance.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add new ebpf helpers bpf_map_lookup_percpu_elem.

The implementation method is relatively simple, refer to the implementation
method of map_lookup_elem of percpu map, increase the parameters of cpu, and
obtain it according to the specified cpu.

Signed-off-by: Feng Zhou &lt;zhoufeng.zf@bytedance.com&gt;
Link: https://lore.kernel.org/r/20220511093854.411-2-zhoufeng.zf@bytedance.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf, x86: Attach a cookie to fentry/fexit/fmod_ret/lsm.</title>
<updated>2022-05-11T04:58:31+00:00</updated>
<author>
<name>Kui-Feng Lee</name>
<email>kuifeng@fb.com</email>
</author>
<published>2022-05-10T20:59:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2fcc82411e74e5e6aba336561cf56fb899bfae4e'/>
<id>2fcc82411e74e5e6aba336561cf56fb899bfae4e</id>
<content type='text'>
Pass a cookie along with BPF_LINK_CREATE requests.

Add a bpf_cookie field to struct bpf_tracing_link to attach a cookie.
The cookie of a bpf_tracing_link is available by calling
bpf_get_attach_cookie when running the BPF program of the attached
link.

The value of a cookie will be set at bpf_tramp_run_ctx by the
trampoline of the link.

Signed-off-by: Kui-Feng Lee &lt;kuifeng@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20220510205923.3206889-4-kuifeng@fb.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pass a cookie along with BPF_LINK_CREATE requests.

Add a bpf_cookie field to struct bpf_tracing_link to attach a cookie.
The cookie of a bpf_tracing_link is available by calling
bpf_get_attach_cookie when running the BPF program of the attached
link.

The value of a cookie will be set at bpf_tramp_run_ctx by the
trampoline of the link.

Signed-off-by: Kui-Feng Lee &lt;kuifeng@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20220510205923.3206889-4-kuifeng@fb.com
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Resolve symbols with ftrace_lookup_symbols for kprobe multi link</title>
<updated>2022-05-10T21:42:06+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2022-05-10T12:26:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0236fec57a15dc2a068dfe4488e0c2ab4559b1ec'/>
<id>0236fec57a15dc2a068dfe4488e0c2ab4559b1ec</id>
<content type='text'>
Using kallsyms_lookup_names function to speed up symbols lookup in
kprobe multi link attachment and replacing with it the current
kprobe_multi_resolve_syms function.

This speeds up bpftrace kprobe attachment:

  # perf stat -r 5 -e cycles ./src/bpftrace -e 'kprobe:x* {  } i:ms:1 { exit(); }'
  ...
  6.5681 +- 0.0225 seconds time elapsed  ( +-  0.34% )

After:

  # perf stat -r 5 -e cycles ./src/bpftrace -e 'kprobe:x* {  } i:ms:1 { exit(); }'
  ...
  0.5661 +- 0.0275 seconds time elapsed  ( +-  4.85% )

Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: https://lore.kernel.org/r/20220510122616.2652285-5-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Using kallsyms_lookup_names function to speed up symbols lookup in
kprobe multi link attachment and replacing with it the current
kprobe_multi_resolve_syms function.

This speeds up bpftrace kprobe attachment:

  # perf stat -r 5 -e cycles ./src/bpftrace -e 'kprobe:x* {  } i:ms:1 { exit(); }'
  ...
  6.5681 +- 0.0225 seconds time elapsed  ( +-  0.34% )

After:

  # perf stat -r 5 -e cycles ./src/bpftrace -e 'kprobe:x* {  } i:ms:1 { exit(); }'
  ...
  0.5661 +- 0.0275 seconds time elapsed  ( +-  4.85% )

Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: https://lore.kernel.org/r/20220510122616.2652285-5-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Move rcu lock management out of BPF_PROG_RUN routines</title>
<updated>2022-04-19T16:45:47+00:00</updated>
<author>
<name>Stanislav Fomichev</name>
<email>sdf@google.com</email>
</author>
<published>2022-04-14T16:12:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=055eb95533273bc334794dbc598400d10800528f'/>
<id>055eb95533273bc334794dbc598400d10800528f</id>
<content type='text'>
Commit 7d08c2c91171 ("bpf: Refactor BPF_PROG_RUN_ARRAY family of macros
into functions") switched a bunch of BPF_PROG_RUN macros to inline
routines. This changed the semantic a bit. Due to arguments expansion
of macros, it used to be:

	rcu_read_lock();
	array = rcu_dereference(cgrp-&gt;bpf.effective[atype]);
	...

Now, with with inline routines, we have:
	array_rcu = rcu_dereference(cgrp-&gt;bpf.effective[atype]);
	/* array_rcu can be kfree'd here */
	rcu_read_lock();
	array = rcu_dereference(array_rcu);

I'm assuming in practice rcu subsystem isn't fast enough to trigger
this but let's use rcu API properly.

Also, rename to lower caps to not confuse with macros. Additionally,
drop and expand BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY.

See [1] for more context.

  [1] https://lore.kernel.org/bpf/CAKH8qBs60fOinFdxiiQikK_q0EcVxGvNTQoWvHLEUGbgcj1UYg@mail.gmail.com/T/#u

v2
- keep rcu locks inside by passing cgroup_bpf

Fixes: 7d08c2c91171 ("bpf: Refactor BPF_PROG_RUN_ARRAY family of macros into functions")
Signed-off-by: Stanislav Fomichev &lt;sdf@google.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Martin KaFai Lau &lt;kafai@fb.com&gt;
Link: https://lore.kernel.org/bpf/20220414161233.170780-1-sdf@google.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 7d08c2c91171 ("bpf: Refactor BPF_PROG_RUN_ARRAY family of macros
into functions") switched a bunch of BPF_PROG_RUN macros to inline
routines. This changed the semantic a bit. Due to arguments expansion
of macros, it used to be:

	rcu_read_lock();
	array = rcu_dereference(cgrp-&gt;bpf.effective[atype]);
	...

Now, with with inline routines, we have:
	array_rcu = rcu_dereference(cgrp-&gt;bpf.effective[atype]);
	/* array_rcu can be kfree'd here */
	rcu_read_lock();
	array = rcu_dereference(array_rcu);

I'm assuming in practice rcu subsystem isn't fast enough to trigger
this but let's use rcu API properly.

Also, rename to lower caps to not confuse with macros. Additionally,
drop and expand BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY.

See [1] for more context.

  [1] https://lore.kernel.org/bpf/CAKH8qBs60fOinFdxiiQikK_q0EcVxGvNTQoWvHLEUGbgcj1UYg@mail.gmail.com/T/#u

v2
- keep rcu locks inside by passing cgroup_bpf

Fixes: 7d08c2c91171 ("bpf: Refactor BPF_PROG_RUN_ARRAY family of macros into functions")
Signed-off-by: Stanislav Fomichev &lt;sdf@google.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Martin KaFai Lau &lt;kafai@fb.com&gt;
Link: https://lore.kernel.org/bpf/20220414161233.170780-1-sdf@google.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2022-04-09T00:07:29+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2022-04-09T00:07:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=34ba23b44c664792a4308ec37b5788a3162944ec'/>
<id>34ba23b44c664792a4308ec37b5788a3162944ec</id>
<content type='text'>
Daniel Borkmann says:

====================
pull-request: bpf-next 2022-04-09

We've added 63 non-merge commits during the last 9 day(s) which contain
a total of 68 files changed, 4852 insertions(+), 619 deletions(-).

The main changes are:

1) Add libbpf support for USDT (User Statically-Defined Tracing) probes.
   USDTs are an abstraction built on top of uprobes, critical for tracing
   and BPF, and widely used in production applications, from Andrii Nakryiko.

2) While Andrii was adding support for x86{-64}-specific logic of parsing
   USDT argument specification, Ilya followed-up with USDT support for s390
   architecture, from Ilya Leoshkevich.

3) Support name-based attaching for uprobe BPF programs in libbpf. The format
   supported is `u[ret]probe/binary_path:[raw_offset|function[+offset]]`, e.g.
   attaching to libc malloc can be done in BPF via SEC("uprobe/libc.so.6:malloc")
   now, from Alan Maguire.

4) Various load/store optimizations for the arm64 JIT to shrink the image
   size by using arm64 str/ldr immediate instructions. Also enable pointer
   authentication to verify return address for JITed code, from Xu Kuohai.

5) BPF verifier fixes for write access checks to helper functions, e.g.
   rd-only memory from bpf_*_cpu_ptr() must not be passed to helpers that
   write into passed buffers, from Kumar Kartikeya Dwivedi.

6) Fix overly excessive stack map allocation for its base map structure and
   buckets which slipped-in from cleanups during the rlimit accounting removal
   back then, from Yuntao Wang.

7) Extend the unstable CT lookup helpers for XDP and tc/BPF to report netfilter
   connection tracking tuple direction, from Lorenzo Bianconi.

8) Improve bpftool dump to show BPF program/link type names, Milan Landaverde.

9) Minor cleanups all over the place from various others.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (63 commits)
  bpf: Fix excessive memory allocation in stack_map_alloc()
  selftests/bpf: Fix return value checks in perf_event_stackmap test
  selftests/bpf: Add CO-RE relos into linked_funcs selftests
  libbpf: Use weak hidden modifier for USDT BPF-side API functions
  libbpf: Don't error out on CO-RE relos for overriden weak subprogs
  samples, bpf: Move routes monitor in xdp_router_ipv4 in a dedicated thread
  libbpf: Allow WEAK and GLOBAL bindings during BTF fixup
  libbpf: Use strlcpy() in path resolution fallback logic
  libbpf: Add s390-specific USDT arg spec parsing logic
  libbpf: Make BPF-side of USDT support work on big-endian machines
  libbpf: Minor style improvements in USDT code
  libbpf: Fix use #ifdef instead of #if to avoid compiler warning
  libbpf: Potential NULL dereference in usdt_manager_attach_usdt()
  selftests/bpf: Uprobe tests should verify param/return values
  libbpf: Improve string parsing for uprobe auto-attach
  libbpf: Improve library identification for uprobe binary path resolution
  selftests/bpf: Test for writes to map key from BPF helpers
  selftests/bpf: Test passing rdonly mem to global func
  bpf: Reject writes for PTR_TO_MAP_KEY in check_helper_mem_access
  bpf: Check PTR_TO_MEM | MEM_RDONLY in check_helper_mem_access
  ...
====================

Link: https://lore.kernel.org/r/20220408231741.19116-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Daniel Borkmann says:

====================
pull-request: bpf-next 2022-04-09

We've added 63 non-merge commits during the last 9 day(s) which contain
a total of 68 files changed, 4852 insertions(+), 619 deletions(-).

The main changes are:

1) Add libbpf support for USDT (User Statically-Defined Tracing) probes.
   USDTs are an abstraction built on top of uprobes, critical for tracing
   and BPF, and widely used in production applications, from Andrii Nakryiko.

2) While Andrii was adding support for x86{-64}-specific logic of parsing
   USDT argument specification, Ilya followed-up with USDT support for s390
   architecture, from Ilya Leoshkevich.

3) Support name-based attaching for uprobe BPF programs in libbpf. The format
   supported is `u[ret]probe/binary_path:[raw_offset|function[+offset]]`, e.g.
   attaching to libc malloc can be done in BPF via SEC("uprobe/libc.so.6:malloc")
   now, from Alan Maguire.

4) Various load/store optimizations for the arm64 JIT to shrink the image
   size by using arm64 str/ldr immediate instructions. Also enable pointer
   authentication to verify return address for JITed code, from Xu Kuohai.

5) BPF verifier fixes for write access checks to helper functions, e.g.
   rd-only memory from bpf_*_cpu_ptr() must not be passed to helpers that
   write into passed buffers, from Kumar Kartikeya Dwivedi.

6) Fix overly excessive stack map allocation for its base map structure and
   buckets which slipped-in from cleanups during the rlimit accounting removal
   back then, from Yuntao Wang.

7) Extend the unstable CT lookup helpers for XDP and tc/BPF to report netfilter
   connection tracking tuple direction, from Lorenzo Bianconi.

8) Improve bpftool dump to show BPF program/link type names, Milan Landaverde.

9) Minor cleanups all over the place from various others.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (63 commits)
  bpf: Fix excessive memory allocation in stack_map_alloc()
  selftests/bpf: Fix return value checks in perf_event_stackmap test
  selftests/bpf: Add CO-RE relos into linked_funcs selftests
  libbpf: Use weak hidden modifier for USDT BPF-side API functions
  libbpf: Don't error out on CO-RE relos for overriden weak subprogs
  samples, bpf: Move routes monitor in xdp_router_ipv4 in a dedicated thread
  libbpf: Allow WEAK and GLOBAL bindings during BTF fixup
  libbpf: Use strlcpy() in path resolution fallback logic
  libbpf: Add s390-specific USDT arg spec parsing logic
  libbpf: Make BPF-side of USDT support work on big-endian machines
  libbpf: Minor style improvements in USDT code
  libbpf: Fix use #ifdef instead of #if to avoid compiler warning
  libbpf: Potential NULL dereference in usdt_manager_attach_usdt()
  selftests/bpf: Uprobe tests should verify param/return values
  libbpf: Improve string parsing for uprobe auto-attach
  libbpf: Improve library identification for uprobe binary path resolution
  selftests/bpf: Test for writes to map key from BPF helpers
  selftests/bpf: Test passing rdonly mem to global func
  bpf: Reject writes for PTR_TO_MAP_KEY in check_helper_mem_access
  bpf: Check PTR_TO_MEM | MEM_RDONLY in check_helper_mem_access
  ...
====================

Link: https://lore.kernel.org/r/20220408231741.19116-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Use swap() instead of open coding it</title>
<updated>2022-04-01T20:27:07+00:00</updated>
<author>
<name>Jiapeng Chong</name>
<email>jiapeng.chong@linux.alibaba.com</email>
</author>
<published>2022-03-22T06:21:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=11e17ae423778f48c84da6a2e215f140610e1973'/>
<id>11e17ae423778f48c84da6a2e215f140610e1973</id>
<content type='text'>
Clean the following coccicheck warning:

./kernel/trace/bpf_trace.c:2263:34-35: WARNING opportunity for swap().
./kernel/trace/bpf_trace.c:2264:40-41: WARNING opportunity for swap().

Reported-by: Abaci Robot &lt;abaci@linux.alibaba.com&gt;
Signed-off-by: Jiapeng Chong &lt;jiapeng.chong@linux.alibaba.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20220322062149.109180-1-jiapeng.chong@linux.alibaba.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Clean the following coccicheck warning:

./kernel/trace/bpf_trace.c:2263:34-35: WARNING opportunity for swap().
./kernel/trace/bpf_trace.c:2264:40-41: WARNING opportunity for swap().

Reported-by: Abaci Robot &lt;abaci@linux.alibaba.com&gt;
Signed-off-by: Jiapeng Chong &lt;jiapeng.chong@linux.alibaba.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20220322062149.109180-1-jiapeng.chong@linux.alibaba.com
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Fix sparse warnings in kprobe_multi_resolve_syms</title>
<updated>2022-03-30T12:10:06+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2022-03-30T11:05:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d31e0386a2f122b40b605eb0120a2fbcfca77868'/>
<id>d31e0386a2f122b40b605eb0120a2fbcfca77868</id>
<content type='text'>
Adding missing __user tags to fix sparse warnings:

kernel/trace/bpf_trace.c:2370:34: warning: incorrect type in argument 2 (different address spaces)
kernel/trace/bpf_trace.c:2370:34:    expected void const [noderef] __user *from
kernel/trace/bpf_trace.c:2370:34:    got void const *usyms
kernel/trace/bpf_trace.c:2376:51: warning: incorrect type in argument 2 (different address spaces)
kernel/trace/bpf_trace.c:2376:51:    expected char const [noderef] __user *src
kernel/trace/bpf_trace.c:2376:51:    got char const *
kernel/trace/bpf_trace.c:2443:49: warning: incorrect type in argument 1 (different address spaces)
kernel/trace/bpf_trace.c:2443:49:    expected void const *usyms
kernel/trace/bpf_trace.c:2443:49:    got void [noderef] __user *[assigned] usyms

Fixes: 0dcac2725406 ("bpf: Add multi kprobe link")
Reported-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Reported-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20220330110510.398558-1-jolsa@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Adding missing __user tags to fix sparse warnings:

kernel/trace/bpf_trace.c:2370:34: warning: incorrect type in argument 2 (different address spaces)
kernel/trace/bpf_trace.c:2370:34:    expected void const [noderef] __user *from
kernel/trace/bpf_trace.c:2370:34:    got void const *usyms
kernel/trace/bpf_trace.c:2376:51: warning: incorrect type in argument 2 (different address spaces)
kernel/trace/bpf_trace.c:2376:51:    expected char const [noderef] __user *src
kernel/trace/bpf_trace.c:2376:51:    got char const *
kernel/trace/bpf_trace.c:2443:49: warning: incorrect type in argument 1 (different address spaces)
kernel/trace/bpf_trace.c:2443:49:    expected void const *usyms
kernel/trace/bpf_trace.c:2443:49:    got void [noderef] __user *[assigned] usyms

Fixes: 0dcac2725406 ("bpf: Add multi kprobe link")
Reported-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Reported-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20220330110510.398558-1-jolsa@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next</title>
<updated>2022-03-24T20:13:26+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-24T20:13:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=169e77764adc041b1dacba84ea90516a895d43b2'/>
<id>169e77764adc041b1dacba84ea90516a895d43b2</id>
<content type='text'>
Pull networking updates from Jakub Kicinski:
 "The sprinkling of SPI drivers is because we added a new one and Mark
  sent us a SPI driver interface conversion pull request.

  Core
  ----

   - Introduce XDP multi-buffer support, allowing the use of XDP with
     jumbo frame MTUs and combination with Rx coalescing offloads (LRO).

   - Speed up netns dismantling (5x) and lower the memory cost a little.
     Remove unnecessary per-netns sockets. Scope some lists to a netns.
     Cut down RCU syncing. Use batch methods. Allow netdev registration
     to complete out of order.

   - Support distinguishing timestamp types (ingress vs egress) and
     maintaining them across packet scrubbing points (e.g. redirect).

   - Continue the work of annotating packet drop reasons throughout the
     stack.

   - Switch netdev error counters from an atomic to dynamically
     allocated per-CPU counters.

   - Rework a few preempt_disable(), local_irq_save() and busy waiting
     sections problematic on PREEMPT_RT.

   - Extend the ref_tracker to allow catching use-after-free bugs.

  BPF
  ---

   - Introduce "packing allocator" for BPF JIT images. JITed code is
     marked read only, and used to be allocated at page granularity.
     Custom allocator allows for more efficient memory use, lower iTLB
     pressure and prevents identity mapping huge pages from getting
     split.

   - Make use of BTF type annotations (e.g. __user, __percpu) to enforce
     the correct probe read access method, add appropriate helpers.

   - Convert the BPF preload to use light skeleton and drop the
     user-mode-driver dependency.

   - Allow XDP BPF_PROG_RUN test infra to send real packets, enabling
     its use as a packet generator.

   - Allow local storage memory to be allocated with GFP_KERNEL if
     called from a hook allowed to sleep.

   - Introduce fprobe (multi kprobe) to speed up mass attachment (arch
     bits to come later).

   - Add unstable conntrack lookup helpers for BPF by using the BPF
     kfunc infra.

   - Allow cgroup BPF progs to return custom errors to user space.

   - Add support for AF_UNIX iterator batching.

   - Allow iterator programs to use sleepable helpers.

   - Support JIT of add, and, or, xor and xchg atomic ops on arm64.

   - Add BTFGen support to bpftool which allows to use CO-RE in kernels
     without BTF info.

   - Large number of libbpf API improvements, cleanups and deprecations.

  Protocols
  ---------

   - Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev.

   - Adjust TSO packet sizes based on min_rtt, allowing very low latency
     links (data centers) to always send full-sized TSO super-frames.

   - Make IPv6 flow label changes (AKA hash rethink) more configurable,
     via sysctl and setsockopt. Distinguish between server and client
     behavior.

   - VxLAN support to "collect metadata" devices to terminate only
     configured VNIs. This is similar to VLAN filtering in the bridge.

   - Support inserting IPv6 IOAM information to a fraction of frames.

   - Add protocol attribute to IP addresses to allow identifying where
     given address comes from (kernel-generated, DHCP etc.)

   - Support setting socket and IPv6 options via cmsg on ping6 sockets.

   - Reject mis-use of ECN bits in IP headers as part of DSCP/TOS.
     Define dscp_t and stop taking ECN bits into account in fib-rules.

   - Add support for locked bridge ports (for 802.1X).

   - tun: support NAPI for packets received from batched XDP buffs,
     doubling the performance in some scenarios.

   - IPv6 extension header handling in Open vSwitch.

   - Support IPv6 control message load balancing in bonding, prevent
     neighbor solicitation and advertisement from using the wrong port.
     Support NS/NA monitor selection similar to existing ARP monitor.

   - SMC
      - improve performance with TCP_CORK and sendfile()
      - support auto-corking
      - support TCP_NODELAY

   - MCTP (Management Component Transport Protocol)
      - add user space tag control interface
      - I2C binding driver (as specified by DMTF DSP0237)

   - Multi-BSSID beacon handling in AP mode for WiFi.

   - Bluetooth:
      - handle MSFT Monitor Device Event
      - add MGMT Adv Monitor Device Found/Lost events

   - Multi-Path TCP:
      - add support for the SO_SNDTIMEO socket option
      - lots of selftest cleanups and improvements

   - Increase the max PDU size in CAN ISOTP to 64 kB.

  Driver API
  ----------

   - Add HW counters for SW netdevs, a mechanism for devices which
     offload packet forwarding to report packet statistics back to
     software interfaces such as tunnels.

   - Select the default NIC queue count as a fraction of number of
     physical CPU cores, instead of hard-coding to 8.

   - Expose devlink instance locks to drivers. Allow device layer of
     drivers to use that lock directly instead of creating their own
     which always runs into ordering issues in devlink callbacks.

   - Add header/data split indication to guide user space enabling of
     TCP zero-copy Rx.

   - Allow configuring completion queue event size.

   - Refactor page_pool to enable fragmenting after allocation.

   - Add allocation and page reuse statistics to page_pool.

   - Improve Multiple Spanning Trees support in the bridge to allow
     reuse of topologies across VLANs, saving HW resources in switches.

   - DSA (Distributed Switch Architecture):
      - replay and offload of host VLAN entries
      - offload of static and local FDB entries on LAG interfaces
      - FDB isolation and unicast filtering

  New hardware / drivers
  ----------------------

   - Ethernet:
      - LAN937x T1 PHYs
      - Davicom DM9051 SPI NIC driver
      - Realtek RTL8367S, RTL8367RB-VB switch and MDIO
      - Microchip ksz8563 switches
      - Netronome NFP3800 SmartNICs
      - Fungible SmartNICs
      - MediaTek MT8195 switches

   - WiFi:
      - mt76: MediaTek mt7916
      - mt76: MediaTek mt7921u USB adapters
      - brcmfmac: Broadcom BCM43454/6

   - Mobile:
      - iosm: Intel M.2 7360 WWAN card

  Drivers
  -------

   - Convert many drivers to the new phylink API built for split PCS
     designs but also simplifying other cases.

   - Intel Ethernet NICs:
      - add TTY for GNSS module for E810T device
      - improve AF_XDP performance
      - GTP-C and GTP-U filter offload
      - QinQ VLAN support

   - Mellanox Ethernet NICs (mlx5):
      - support xdp-&gt;data_meta
      - multi-buffer XDP
      - offload tc push_eth and pop_eth actions

   - Netronome Ethernet NICs (nfp):
      - flow-independent tc action hardware offload (police / meter)
      - AF_XDP

   - Other Ethernet NICs:
      - at803x: fiber and SFP support
      - xgmac: mdio: preamble suppression and custom MDC frequencies
      - r8169: enable ASPM L1.2 if system vendor flags it as safe
      - macb/gem: ZynqMP SGMII
      - hns3: add TX push mode
      - dpaa2-eth: software TSO
      - lan743x: multi-queue, mdio, SGMII, PTP
      - axienet: NAPI and GRO support

   - Mellanox Ethernet switches (mlxsw):
      - source and dest IP address rewrites
      - RJ45 ports

   - Marvell Ethernet switches (prestera):
      - basic routing offload
      - multi-chain TC ACL offload

   - NXP embedded Ethernet switches (ocelot &amp; felix):
      - PTP over UDP with the ocelot-8021q DSA tagging protocol
      - basic QoS classification on Felix DSA switch using dcbnl
      - port mirroring for ocelot switches

   - Microchip high-speed industrial Ethernet (sparx5):
      - offloading of bridge port flooding flags
      - PTP Hardware Clock

   - Other embedded switches:
      - lan966x: PTP Hardward Clock
      - qca8k: mdio read/write operations via crafted Ethernet packets

   - Qualcomm 802.11ax WiFi (ath11k):
      - add LDPC FEC type and 802.11ax High Efficiency data in radiotap
      - enable RX PPDU stats in monitor co-exist mode

   - Intel WiFi (iwlwifi):
      - UHB TAS enablement via BIOS
      - band disablement via BIOS
      - channel switch offload
      - 32 Rx AMPDU sessions in newer devices

   - MediaTek WiFi (mt76):
      - background radar detection
      - thermal management improvements on mt7915
      - SAR support for more mt76 platforms
      - MBSSID and 6 GHz band on mt7915

   - RealTek WiFi:
      - rtw89: AP mode
      - rtw89: 160 MHz channels and 6 GHz band
      - rtw89: hardware scan

   - Bluetooth:
      - mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS)

   - Microchip CAN (mcp251xfd):
      - multiple RX-FIFOs and runtime configurable RX/TX rings
      - internal PLL, runtime PM handling simplification
      - improve chip detection and error handling after wakeup"

* tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2521 commits)
  llc: fix netdevice reference leaks in llc_ui_bind()
  drivers: ethernet: cpsw: fix panic when interrupt coaleceing is set via ethtool
  ice: don't allow to run ice_send_event_to_aux() in atomic ctx
  ice: fix 'scheduling while atomic' on aux critical err interrupt
  net/sched: fix incorrect vlan_push_eth dest field
  net: bridge: mst: Restrict info size queries to bridge ports
  net: marvell: prestera: add missing destroy_workqueue() in prestera_module_init()
  drivers: net: xgene: Fix regression in CRC stripping
  net: geneve: add missing netlink policy and size for IFLA_GENEVE_INNER_PROTO_INHERIT
  net: dsa: fix missing host-filtered multicast addresses
  net/mlx5e: Fix build warning, detected write beyond size of field
  iwlwifi: mvm: Don't fail if PPAG isn't supported
  selftests/bpf: Fix kprobe_multi test.
  Revert "rethook: x86: Add rethook x86 implementation"
  Revert "arm64: rethook: Add arm64 rethook implementation"
  Revert "powerpc: Add rethook support"
  Revert "ARM: rethook: Add rethook arm implementation"
  netdevice: add missing dm_private kdoc
  net: bridge: mst: prevent NULL deref in br_mst_info_size()
  selftests: forwarding: Use same VRF for port and VLAN upper
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking updates from Jakub Kicinski:
 "The sprinkling of SPI drivers is because we added a new one and Mark
  sent us a SPI driver interface conversion pull request.

  Core
  ----

   - Introduce XDP multi-buffer support, allowing the use of XDP with
     jumbo frame MTUs and combination with Rx coalescing offloads (LRO).

   - Speed up netns dismantling (5x) and lower the memory cost a little.
     Remove unnecessary per-netns sockets. Scope some lists to a netns.
     Cut down RCU syncing. Use batch methods. Allow netdev registration
     to complete out of order.

   - Support distinguishing timestamp types (ingress vs egress) and
     maintaining them across packet scrubbing points (e.g. redirect).

   - Continue the work of annotating packet drop reasons throughout the
     stack.

   - Switch netdev error counters from an atomic to dynamically
     allocated per-CPU counters.

   - Rework a few preempt_disable(), local_irq_save() and busy waiting
     sections problematic on PREEMPT_RT.

   - Extend the ref_tracker to allow catching use-after-free bugs.

  BPF
  ---

   - Introduce "packing allocator" for BPF JIT images. JITed code is
     marked read only, and used to be allocated at page granularity.
     Custom allocator allows for more efficient memory use, lower iTLB
     pressure and prevents identity mapping huge pages from getting
     split.

   - Make use of BTF type annotations (e.g. __user, __percpu) to enforce
     the correct probe read access method, add appropriate helpers.

   - Convert the BPF preload to use light skeleton and drop the
     user-mode-driver dependency.

   - Allow XDP BPF_PROG_RUN test infra to send real packets, enabling
     its use as a packet generator.

   - Allow local storage memory to be allocated with GFP_KERNEL if
     called from a hook allowed to sleep.

   - Introduce fprobe (multi kprobe) to speed up mass attachment (arch
     bits to come later).

   - Add unstable conntrack lookup helpers for BPF by using the BPF
     kfunc infra.

   - Allow cgroup BPF progs to return custom errors to user space.

   - Add support for AF_UNIX iterator batching.

   - Allow iterator programs to use sleepable helpers.

   - Support JIT of add, and, or, xor and xchg atomic ops on arm64.

   - Add BTFGen support to bpftool which allows to use CO-RE in kernels
     without BTF info.

   - Large number of libbpf API improvements, cleanups and deprecations.

  Protocols
  ---------

   - Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev.

   - Adjust TSO packet sizes based on min_rtt, allowing very low latency
     links (data centers) to always send full-sized TSO super-frames.

   - Make IPv6 flow label changes (AKA hash rethink) more configurable,
     via sysctl and setsockopt. Distinguish between server and client
     behavior.

   - VxLAN support to "collect metadata" devices to terminate only
     configured VNIs. This is similar to VLAN filtering in the bridge.

   - Support inserting IPv6 IOAM information to a fraction of frames.

   - Add protocol attribute to IP addresses to allow identifying where
     given address comes from (kernel-generated, DHCP etc.)

   - Support setting socket and IPv6 options via cmsg on ping6 sockets.

   - Reject mis-use of ECN bits in IP headers as part of DSCP/TOS.
     Define dscp_t and stop taking ECN bits into account in fib-rules.

   - Add support for locked bridge ports (for 802.1X).

   - tun: support NAPI for packets received from batched XDP buffs,
     doubling the performance in some scenarios.

   - IPv6 extension header handling in Open vSwitch.

   - Support IPv6 control message load balancing in bonding, prevent
     neighbor solicitation and advertisement from using the wrong port.
     Support NS/NA monitor selection similar to existing ARP monitor.

   - SMC
      - improve performance with TCP_CORK and sendfile()
      - support auto-corking
      - support TCP_NODELAY

   - MCTP (Management Component Transport Protocol)
      - add user space tag control interface
      - I2C binding driver (as specified by DMTF DSP0237)

   - Multi-BSSID beacon handling in AP mode for WiFi.

   - Bluetooth:
      - handle MSFT Monitor Device Event
      - add MGMT Adv Monitor Device Found/Lost events

   - Multi-Path TCP:
      - add support for the SO_SNDTIMEO socket option
      - lots of selftest cleanups and improvements

   - Increase the max PDU size in CAN ISOTP to 64 kB.

  Driver API
  ----------

   - Add HW counters for SW netdevs, a mechanism for devices which
     offload packet forwarding to report packet statistics back to
     software interfaces such as tunnels.

   - Select the default NIC queue count as a fraction of number of
     physical CPU cores, instead of hard-coding to 8.

   - Expose devlink instance locks to drivers. Allow device layer of
     drivers to use that lock directly instead of creating their own
     which always runs into ordering issues in devlink callbacks.

   - Add header/data split indication to guide user space enabling of
     TCP zero-copy Rx.

   - Allow configuring completion queue event size.

   - Refactor page_pool to enable fragmenting after allocation.

   - Add allocation and page reuse statistics to page_pool.

   - Improve Multiple Spanning Trees support in the bridge to allow
     reuse of topologies across VLANs, saving HW resources in switches.

   - DSA (Distributed Switch Architecture):
      - replay and offload of host VLAN entries
      - offload of static and local FDB entries on LAG interfaces
      - FDB isolation and unicast filtering

  New hardware / drivers
  ----------------------

   - Ethernet:
      - LAN937x T1 PHYs
      - Davicom DM9051 SPI NIC driver
      - Realtek RTL8367S, RTL8367RB-VB switch and MDIO
      - Microchip ksz8563 switches
      - Netronome NFP3800 SmartNICs
      - Fungible SmartNICs
      - MediaTek MT8195 switches

   - WiFi:
      - mt76: MediaTek mt7916
      - mt76: MediaTek mt7921u USB adapters
      - brcmfmac: Broadcom BCM43454/6

   - Mobile:
      - iosm: Intel M.2 7360 WWAN card

  Drivers
  -------

   - Convert many drivers to the new phylink API built for split PCS
     designs but also simplifying other cases.

   - Intel Ethernet NICs:
      - add TTY for GNSS module for E810T device
      - improve AF_XDP performance
      - GTP-C and GTP-U filter offload
      - QinQ VLAN support

   - Mellanox Ethernet NICs (mlx5):
      - support xdp-&gt;data_meta
      - multi-buffer XDP
      - offload tc push_eth and pop_eth actions

   - Netronome Ethernet NICs (nfp):
      - flow-independent tc action hardware offload (police / meter)
      - AF_XDP

   - Other Ethernet NICs:
      - at803x: fiber and SFP support
      - xgmac: mdio: preamble suppression and custom MDC frequencies
      - r8169: enable ASPM L1.2 if system vendor flags it as safe
      - macb/gem: ZynqMP SGMII
      - hns3: add TX push mode
      - dpaa2-eth: software TSO
      - lan743x: multi-queue, mdio, SGMII, PTP
      - axienet: NAPI and GRO support

   - Mellanox Ethernet switches (mlxsw):
      - source and dest IP address rewrites
      - RJ45 ports

   - Marvell Ethernet switches (prestera):
      - basic routing offload
      - multi-chain TC ACL offload

   - NXP embedded Ethernet switches (ocelot &amp; felix):
      - PTP over UDP with the ocelot-8021q DSA tagging protocol
      - basic QoS classification on Felix DSA switch using dcbnl
      - port mirroring for ocelot switches

   - Microchip high-speed industrial Ethernet (sparx5):
      - offloading of bridge port flooding flags
      - PTP Hardware Clock

   - Other embedded switches:
      - lan966x: PTP Hardward Clock
      - qca8k: mdio read/write operations via crafted Ethernet packets

   - Qualcomm 802.11ax WiFi (ath11k):
      - add LDPC FEC type and 802.11ax High Efficiency data in radiotap
      - enable RX PPDU stats in monitor co-exist mode

   - Intel WiFi (iwlwifi):
      - UHB TAS enablement via BIOS
      - band disablement via BIOS
      - channel switch offload
      - 32 Rx AMPDU sessions in newer devices

   - MediaTek WiFi (mt76):
      - background radar detection
      - thermal management improvements on mt7915
      - SAR support for more mt76 platforms
      - MBSSID and 6 GHz band on mt7915

   - RealTek WiFi:
      - rtw89: AP mode
      - rtw89: 160 MHz channels and 6 GHz band
      - rtw89: hardware scan

   - Bluetooth:
      - mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS)

   - Microchip CAN (mcp251xfd):
      - multiple RX-FIFOs and runtime configurable RX/TX rings
      - internal PLL, runtime PM handling simplification
      - improve chip detection and error handling after wakeup"

* tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2521 commits)
  llc: fix netdevice reference leaks in llc_ui_bind()
  drivers: ethernet: cpsw: fix panic when interrupt coaleceing is set via ethtool
  ice: don't allow to run ice_send_event_to_aux() in atomic ctx
  ice: fix 'scheduling while atomic' on aux critical err interrupt
  net/sched: fix incorrect vlan_push_eth dest field
  net: bridge: mst: Restrict info size queries to bridge ports
  net: marvell: prestera: add missing destroy_workqueue() in prestera_module_init()
  drivers: net: xgene: Fix regression in CRC stripping
  net: geneve: add missing netlink policy and size for IFLA_GENEVE_INNER_PROTO_INHERIT
  net: dsa: fix missing host-filtered multicast addresses
  net/mlx5e: Fix build warning, detected write beyond size of field
  iwlwifi: mvm: Don't fail if PPAG isn't supported
  selftests/bpf: Fix kprobe_multi test.
  Revert "rethook: x86: Add rethook x86 implementation"
  Revert "arm64: rethook: Add arm64 rethook implementation"
  Revert "powerpc: Add rethook support"
  Revert "ARM: rethook: Add rethook arm implementation"
  netdevice: add missing dm_private kdoc
  net: bridge: mst: prevent NULL deref in br_mst_info_size()
  selftests: forwarding: Use same VRF for port and VLAN upper
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Fix kprobe_multi return probe backtrace</title>
<updated>2022-03-21T13:54:15+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2022-03-21T07:01:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f70986902c86f88612ed45a96aa7cf4caa65f7c1'/>
<id>f70986902c86f88612ed45a96aa7cf4caa65f7c1</id>
<content type='text'>
Andrii reported that backtraces from kprobe_multi program attached
as return probes are not complete and showing just initial entry [1].

It's caused by changing registers to have original function ip address
as instruction pointer even for return probe, which will screw backtrace
from return probe.

This change keeps registers intact and store original entry ip and
link address on the stack in bpf_kprobe_multi_run_ctx struct, where
bpf_get_func_ip and bpf_get_attach_cookie helpers for kprobe_multi
programs can find it.

[1] https://lore.kernel.org/bpf/CAEf4BzZDDqK24rSKwXNp7XL3ErGD4bZa1M6c_c4EvDSt3jrZcg@mail.gmail.com/T/#m8d1301c0ea0892ddf9dc6fba57a57b8cf11b8c51

Fixes: ca74823c6e16 ("bpf: Add cookie support to programs attached with kprobe multi link")
Reported-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20220321070113.1449167-3-jolsa@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Andrii reported that backtraces from kprobe_multi program attached
as return probes are not complete and showing just initial entry [1].

It's caused by changing registers to have original function ip address
as instruction pointer even for return probe, which will screw backtrace
from return probe.

This change keeps registers intact and store original entry ip and
link address on the stack in bpf_kprobe_multi_run_ctx struct, where
bpf_get_func_ip and bpf_get_attach_cookie helpers for kprobe_multi
programs can find it.

[1] https://lore.kernel.org/bpf/CAEf4BzZDDqK24rSKwXNp7XL3ErGD4bZa1M6c_c4EvDSt3jrZcg@mail.gmail.com/T/#m8d1301c0ea0892ddf9dc6fba57a57b8cf11b8c51

Fixes: ca74823c6e16 ("bpf: Add cookie support to programs attached with kprobe multi link")
Reported-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20220321070113.1449167-3-jolsa@kernel.org
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