<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/tools/testing/selftests/bpf, branch v5.11-rc2</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>Merge tag 'kbuild-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild</title>
<updated>2020-12-22T22:02:39+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-12-22T22:02:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7b95f0563ab5a8f75195cdd4b2c3325c0c1df319'/>
<id>7b95f0563ab5a8f75195cdd4b2c3325c0c1df319</id>
<content type='text'>
Pull Kbuild updates from Masahiro Yamada:

 - Use /usr/bin/env for shebang lines in scripts

 - Remove useless -Wnested-externs warning flag

 - Update documents

 - Refactor log handling in modpost

 - Stop building modules without MODULE_LICENSE() tag

 - Make the insane combination of 'static' and EXPORT_SYMBOL an error

 - Improve genksyms to handle _Static_assert()

* tag 'kbuild-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  Documentation/kbuild: Document platform dependency practises
  Documentation/kbuild: Document COMPILE_TEST dependencies
  genksyms: Ignore module scoped _Static_assert()
  modpost: turn static exports into error
  modpost: turn section mismatches to error from fatal()
  modpost: change license incompatibility to error() from fatal()
  modpost: turn missing MODULE_LICENSE() into error
  modpost: refactor error handling and clarify error/fatal difference
  modpost: rename merror() to error()
  kbuild: don't hardcode depmod path
  kbuild: doc: document subdir-y syntax
  kbuild: doc: clarify the difference between extra-y and always-y
  kbuild: doc: split if_changed explanation to a separate section
  kbuild: doc: merge 'Special Rules' and 'Custom kbuild commands' sections
  kbuild: doc: fix 'List directories to visit when descending' section
  kbuild: doc: replace arch/$(ARCH)/ with arch/$(SRCARCH)/
  kbuild: doc: update the description about kbuild Makefiles
  Makefile.extrawarn: remove -Wnested-externs warning
  tweewide: Fix most Shebang lines
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull Kbuild updates from Masahiro Yamada:

 - Use /usr/bin/env for shebang lines in scripts

 - Remove useless -Wnested-externs warning flag

 - Update documents

 - Refactor log handling in modpost

 - Stop building modules without MODULE_LICENSE() tag

 - Make the insane combination of 'static' and EXPORT_SYMBOL an error

 - Improve genksyms to handle _Static_assert()

* tag 'kbuild-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  Documentation/kbuild: Document platform dependency practises
  Documentation/kbuild: Document COMPILE_TEST dependencies
  genksyms: Ignore module scoped _Static_assert()
  modpost: turn static exports into error
  modpost: turn section mismatches to error from fatal()
  modpost: change license incompatibility to error() from fatal()
  modpost: turn missing MODULE_LICENSE() into error
  modpost: refactor error handling and clarify error/fatal difference
  modpost: rename merror() to error()
  kbuild: don't hardcode depmod path
  kbuild: doc: document subdir-y syntax
  kbuild: doc: clarify the difference between extra-y and always-y
  kbuild: doc: split if_changed explanation to a separate section
  kbuild: doc: merge 'Special Rules' and 'Custom kbuild commands' sections
  kbuild: doc: fix 'List directories to visit when descending' section
  kbuild: doc: replace arch/$(ARCH)/ with arch/$(SRCARCH)/
  kbuild: doc: update the description about kbuild Makefiles
  Makefile.extrawarn: remove -Wnested-externs warning
  tweewide: Fix most Shebang lines
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2020-12-14T23:34:36+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2020-12-14T23:34:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a6b5e026e6238cbdd51e3c9b77cc3c79a7c24a9a'/>
<id>a6b5e026e6238cbdd51e3c9b77cc3c79a7c24a9a</id>
<content type='text'>
Daniel Borkmann says:

====================
pull-request: bpf-next 2020-12-14

1) Expose bpf_sk_storage_*() helpers to iterator programs, from Florent Revest.

2) Add AF_XDP selftests based on veth devs to BPF selftests, from Weqaar Janjua.

3) Support for finding BTF based kernel attach targets through libbpf's
   bpf_program__set_attach_target() API, from Andrii Nakryiko.

4) Permit pointers on stack for helper calls in the verifier, from Yonghong Song.

5) Fix overflows in hash map elem size after rlimit removal, from Eric Dumazet.

6) Get rid of direct invocation of llc in BPF selftests, from Andrew Delgadillo.

7) Fix xsk_recvmsg() to reorder socket state check before access, from Björn Töpel.

8) Add new libbpf API helper to retrieve ring buffer epoll fd, from Brendan Jackman.

9) Batch of minor BPF selftest improvements all over the place, from Florian Lehner,
   KP Singh, Jiri Olsa and various others.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (31 commits)
  selftests/bpf: Add a test for ptr_to_map_value on stack for helper access
  bpf: Permits pointers on stack for helper calls
  libbpf: Expose libbpf ring_buffer epoll_fd
  selftests/bpf: Add set_attach_target() API selftest for module target
  libbpf: Support modules in bpf_program__set_attach_target() API
  selftests/bpf: Silence ima_setup.sh when not running in verbose mode.
  selftests/bpf: Drop the need for LLVM's llc
  selftests/bpf: fix bpf_testmod.ko recompilation logic
  samples/bpf: Fix possible hang in xdpsock with multiple threads
  selftests/bpf: Make selftest compilation work on clang 11
  selftests/bpf: Xsk selftests - adding xdpxceiver to .gitignore
  selftests/bpf: Drop tcp-{client,server}.py from Makefile
  selftests/bpf: Xsk selftests - Bi-directional Sockets - SKB, DRV
  selftests/bpf: Xsk selftests - Socket Teardown - SKB, DRV
  selftests/bpf: Xsk selftests - DRV POLL, NOPOLL
  selftests/bpf: Xsk selftests - SKB POLL, NOPOLL
  selftests/bpf: Xsk selftests framework
  bpf: Only provide bpf_sock_from_file with CONFIG_NET
  bpf: Return -ENOTSUPP when attaching to non-kernel BTF
  xsk: Validate socket state in xsk_recvmsg, prior touching socket members
  ...
====================

Link: https://lore.kernel.org/r/20201214214316.20642-1-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 2020-12-14

1) Expose bpf_sk_storage_*() helpers to iterator programs, from Florent Revest.

2) Add AF_XDP selftests based on veth devs to BPF selftests, from Weqaar Janjua.

3) Support for finding BTF based kernel attach targets through libbpf's
   bpf_program__set_attach_target() API, from Andrii Nakryiko.

4) Permit pointers on stack for helper calls in the verifier, from Yonghong Song.

5) Fix overflows in hash map elem size after rlimit removal, from Eric Dumazet.

6) Get rid of direct invocation of llc in BPF selftests, from Andrew Delgadillo.

7) Fix xsk_recvmsg() to reorder socket state check before access, from Björn Töpel.

8) Add new libbpf API helper to retrieve ring buffer epoll fd, from Brendan Jackman.

9) Batch of minor BPF selftest improvements all over the place, from Florian Lehner,
   KP Singh, Jiri Olsa and various others.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (31 commits)
  selftests/bpf: Add a test for ptr_to_map_value on stack for helper access
  bpf: Permits pointers on stack for helper calls
  libbpf: Expose libbpf ring_buffer epoll_fd
  selftests/bpf: Add set_attach_target() API selftest for module target
  libbpf: Support modules in bpf_program__set_attach_target() API
  selftests/bpf: Silence ima_setup.sh when not running in verbose mode.
  selftests/bpf: Drop the need for LLVM's llc
  selftests/bpf: fix bpf_testmod.ko recompilation logic
  samples/bpf: Fix possible hang in xdpsock with multiple threads
  selftests/bpf: Make selftest compilation work on clang 11
  selftests/bpf: Xsk selftests - adding xdpxceiver to .gitignore
  selftests/bpf: Drop tcp-{client,server}.py from Makefile
  selftests/bpf: Xsk selftests - Bi-directional Sockets - SKB, DRV
  selftests/bpf: Xsk selftests - Socket Teardown - SKB, DRV
  selftests/bpf: Xsk selftests - DRV POLL, NOPOLL
  selftests/bpf: Xsk selftests - SKB POLL, NOPOLL
  selftests/bpf: Xsk selftests framework
  bpf: Only provide bpf_sock_from_file with CONFIG_NET
  bpf: Return -ENOTSUPP when attaching to non-kernel BTF
  xsk: Validate socket state in xsk_recvmsg, prior touching socket members
  ...
====================

Link: https://lore.kernel.org/r/20201214214316.20642-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: Add a test for ptr_to_map_value on stack for helper access</title>
<updated>2020-12-14T20:50:10+00:00</updated>
<author>
<name>Yonghong Song</name>
<email>yhs@fb.com</email>
</author>
<published>2020-12-10T01:33:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b4b638c36b7e7acd847b9c4b9c80f268e45ea30c'/>
<id>b4b638c36b7e7acd847b9c4b9c80f268e45ea30c</id>
<content type='text'>
Change bpf_iter_task.c such that pointer to map_value may appear
on the stack for bpf_seq_printf() to access. Without previous
verifier patch, the bpf_iter test will fail.

Signed-off-by: Yonghong Song &lt;yhs@fb.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Link: https://lore.kernel.org/bpf/20201210013350.943985-1-yhs@fb.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Change bpf_iter_task.c such that pointer to map_value may appear
on the stack for bpf_seq_printf() to access. Without previous
verifier patch, the bpf_iter test will fail.

Signed-off-by: Yonghong Song &lt;yhs@fb.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Link: https://lore.kernel.org/bpf/20201210013350.943985-1-yhs@fb.com
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: Add set_attach_target() API selftest for module target</title>
<updated>2020-12-14T15:39:42+00:00</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andrii@kernel.org</email>
</author>
<published>2020-12-11T21:58:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2e33f831fccd2df83836a8e255755f85d364aaeb'/>
<id>2e33f831fccd2df83836a8e255755f85d364aaeb</id>
<content type='text'>
Add test for bpf_program__set_attach_target() API, validating it can find
kernel module fentry target.

Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20201211215825.3646154-3-andrii@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add test for bpf_program__set_attach_target() API, validating it can find
kernel module fentry target.

Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20201211215825.3646154-3-andrii@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2020-12-12T06:29:38+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2020-12-12T04:12:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=46d5e62dd3c34770f3bfd0642daa9a7772a00362'/>
<id>46d5e62dd3c34770f3bfd0642daa9a7772a00362</id>
<content type='text'>
xdp_return_frame_bulk() needs to pass a xdp_buff
to __xdp_return().

strlcpy got converted to strscpy but here it makes no
functional difference, so just keep the right code.

Conflicts:
	net/netfilter/nf_tables_api.c

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
xdp_return_frame_bulk() needs to pass a xdp_buff
to __xdp_return().

strlcpy got converted to strscpy but here it makes no
functional difference, so just keep the right code.

Conflicts:
	net/netfilter/nf_tables_api.c

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: Silence ima_setup.sh when not running in verbose mode.</title>
<updated>2020-12-11T06:14:32+00:00</updated>
<author>
<name>KP Singh</name>
<email>kpsingh@kernel.org</email>
</author>
<published>2020-12-11T01:07:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b4fe9fec51ef48011f11c2da4099f0b530449c92'/>
<id>b4fe9fec51ef48011f11c2da4099f0b530449c92</id>
<content type='text'>
Currently, ima_setup.sh spews outputs from commands like mkfs and dd
on the terminal without taking into account the verbosity level of
the test framework. Update test_progs to set the environment variable
SELFTESTS_VERBOSE=1 when a verbose output is requested. This
environment variable is then used by ima_setup.sh (and can be used by
other similar scripts) to obey the verbosity level of the test harness
without needing to re-implement command line options for verbosity.

In "silent" mode, the script saves the output to a temporary file, the
contents of which are echoed back to stderr when the script encounters
an error.

Fixes: 34b82d3ac105 ("bpf: Add a selftest for bpf_ima_inode_hash")
Reported-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Suggested-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: KP Singh &lt;kpsingh@kernel.org&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20201211010711.3716917-1-kpsingh@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, ima_setup.sh spews outputs from commands like mkfs and dd
on the terminal without taking into account the verbosity level of
the test framework. Update test_progs to set the environment variable
SELFTESTS_VERBOSE=1 when a verbose output is requested. This
environment variable is then used by ima_setup.sh (and can be used by
other similar scripts) to obey the verbosity level of the test harness
without needing to re-implement command line options for verbosity.

In "silent" mode, the script saves the output to a temporary file, the
contents of which are echoed back to stderr when the script encounters
an error.

Fixes: 34b82d3ac105 ("bpf: Add a selftest for bpf_ima_inode_hash")
Reported-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Suggested-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: KP Singh &lt;kpsingh@kernel.org&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20201211010711.3716917-1-kpsingh@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: Drop the need for LLVM's llc</title>
<updated>2020-12-11T05:33:27+00:00</updated>
<author>
<name>Andrew Delgadillo</name>
<email>adelg@google.com</email>
</author>
<published>2020-12-11T00:43:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=89ad7420b25c2b40a4d916f4fd43b9ccacd50500'/>
<id>89ad7420b25c2b40a4d916f4fd43b9ccacd50500</id>
<content type='text'>
LLC is meant for compiler development and debugging. Consequently, it
exposes many low level options about its backend. To avoid future bugs
introduced by using the raw LLC tool, use clang directly so that all
appropriate options are passed to the back end.

Additionally, simplify the Makefile by removing the
CLANG_NATIVE_BPF_BUILD_RULE as it is not being use, stop passing
dwarfris attr since elfutils/libdw now supports the bpf backend (which
should work with any recent pahole), and stop passing alu32 since
-mcpu=v3 implies alu32.

Signed-off-by: Andrew Delgadillo &lt;adelg@google.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Yonghong Song &lt;yhs@fb.com&gt;
Link: https://lore.kernel.org/bpf/20201211004344.3355074-1-adelg@google.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
LLC is meant for compiler development and debugging. Consequently, it
exposes many low level options about its backend. To avoid future bugs
introduced by using the raw LLC tool, use clang directly so that all
appropriate options are passed to the back end.

Additionally, simplify the Makefile by removing the
CLANG_NATIVE_BPF_BUILD_RULE as it is not being use, stop passing
dwarfris attr since elfutils/libdw now supports the bpf backend (which
should work with any recent pahole), and stop passing alu32 since
-mcpu=v3 implies alu32.

Signed-off-by: Andrew Delgadillo &lt;adelg@google.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Yonghong Song &lt;yhs@fb.com&gt;
Link: https://lore.kernel.org/bpf/20201211004344.3355074-1-adelg@google.com
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: fix bpf_testmod.ko recompilation logic</title>
<updated>2020-12-11T05:16:29+00:00</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andrii@kernel.org</email>
</author>
<published>2020-12-11T01:59:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a67079b03165a17f9aceab3dd26b1638af68e0fc'/>
<id>a67079b03165a17f9aceab3dd26b1638af68e0fc</id>
<content type='text'>
bpf_testmod.ko build rule declared dependency on VMLINUX_BTF, but the variable
itself was initialized after the rule was declared, which often caused
bpf_testmod.ko to not be re-compiled. Fix by moving VMLINUX_BTF determination
sooner.

Also enforce bpf_testmod.ko recompilation when we detect that vmlinux image
changed by removing bpf_testmod/bpf_testmod.ko. This is necessary to generate
correct module's split BTF. Without it, Kbuild's module build logic might
determine that nothing changed on the kernel side and thus bpf_testmod.ko
shouldn't be rebuilt, so won't re-generate module BTF, which often leads to
module's BTF with wrong string offsets against vmlinux BTF. Removing .ko file
forces Kbuild to re-build the module.

Reported-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Fixes: 9f7fa225894c ("selftests/bpf: Add bpf_testmod kernel module for testing")
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/r/20201211015946.4062098-1-andrii@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>
bpf_testmod.ko build rule declared dependency on VMLINUX_BTF, but the variable
itself was initialized after the rule was declared, which often caused
bpf_testmod.ko to not be re-compiled. Fix by moving VMLINUX_BTF determination
sooner.

Also enforce bpf_testmod.ko recompilation when we detect that vmlinux image
changed by removing bpf_testmod/bpf_testmod.ko. This is necessary to generate
correct module's split BTF. Without it, Kbuild's module build logic might
determine that nothing changed on the kernel side and thus bpf_testmod.ko
shouldn't be rebuilt, so won't re-generate module BTF, which often leads to
module's BTF with wrong string offsets against vmlinux BTF. Removing .ko file
forces Kbuild to re-build the module.

Reported-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Fixes: 9f7fa225894c ("selftests/bpf: Add bpf_testmod kernel module for testing")
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/r/20201211015946.4062098-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: Fix "dubious pointer arithmetic" test</title>
<updated>2020-12-10T21:11:30+00:00</updated>
<author>
<name>Jean-Philippe Brucker</name>
<email>jean-philippe@linaro.org</email>
</author>
<published>2020-12-08T18:01:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3615bdf6d9b19db12b1589861609b4f1c6a8d303'/>
<id>3615bdf6d9b19db12b1589861609b4f1c6a8d303</id>
<content type='text'>
The verifier trace changed following a bugfix. After checking the 64-bit
sign, only the upper bit mask is known, not bit 31. Update the test
accordingly.

Signed-off-by: Jean-Philippe Brucker &lt;jean-philippe@linaro.org&gt;
Acked-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The verifier trace changed following a bugfix. After checking the 64-bit
sign, only the upper bit mask is known, not bit 31. Update the test
accordingly.

Signed-off-by: Jean-Philippe Brucker &lt;jean-philippe@linaro.org&gt;
Acked-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: Fix array access with signed variable test</title>
<updated>2020-12-10T21:11:30+00:00</updated>
<author>
<name>Jean-Philippe Brucker</name>
<email>jean-philippe@linaro.org</email>
</author>
<published>2020-12-08T18:01:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=77ce220c0549dcc3db8226c61c60e83fc59dfafc'/>
<id>77ce220c0549dcc3db8226c61c60e83fc59dfafc</id>
<content type='text'>
The test fails because of a recent fix to the verifier, even though this
program is valid. In details what happens is:

    7: (61) r1 = *(u32 *)(r0 +0)

Load a 32-bit value, with signed bounds [S32_MIN, S32_MAX]. The bounds
of the 64-bit value are [0, U32_MAX]...

    8: (65) if r1 s&gt; 0xffffffff goto pc+1

... therefore this is always true (the operand is sign-extended).

    10: (b4) w2 = 11
    11: (6d) if r2 s&gt; r1 goto pc+1

When true, the 64-bit bounds become [0, 10]. The 32-bit bounds are still
[S32_MIN, 10].

    13: (64) w1 &lt;&lt;= 2

Because this is a 32-bit operation, the verifier propagates the new
32-bit bounds to the 64-bit ones, and the knowledge gained from insn 11
is lost.

    14: (0f) r0 += r1
    15: (7a) *(u64 *)(r0 +0) = 4

Then the verifier considers r0 unbounded here, rejecting the test. To
make the test work, change insn 8 to check the sign of the 32-bit value.

Signed-off-by: Jean-Philippe Brucker &lt;jean-philippe@linaro.org&gt;
Acked-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The test fails because of a recent fix to the verifier, even though this
program is valid. In details what happens is:

    7: (61) r1 = *(u32 *)(r0 +0)

Load a 32-bit value, with signed bounds [S32_MIN, S32_MAX]. The bounds
of the 64-bit value are [0, U32_MAX]...

    8: (65) if r1 s&gt; 0xffffffff goto pc+1

... therefore this is always true (the operand is sign-extended).

    10: (b4) w2 = 11
    11: (6d) if r2 s&gt; r1 goto pc+1

When true, the 64-bit bounds become [0, 10]. The 32-bit bounds are still
[S32_MIN, 10].

    13: (64) w1 &lt;&lt;= 2

Because this is a 32-bit operation, the verifier propagates the new
32-bit bounds to the 64-bit ones, and the knowledge gained from insn 11
is lost.

    14: (0f) r0 += r1
    15: (7a) *(u64 *)(r0 +0) = 4

Then the verifier considers r0 unbounded here, rejecting the test. To
make the test work, change insn 8 to check the sign of the 32-bit value.

Signed-off-by: Jean-Philippe Brucker &lt;jean-philippe@linaro.org&gt;
Acked-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
