<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/samples/bpf, branch v6.6.132</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>samples/bpf: Fix compilation failure for samples/bpf on LoongArch Fedora</title>
<updated>2025-06-04T12:41:53+00:00</updated>
<author>
<name>Haoran Jiang</name>
<email>jianghaoran@kylinos.cn</email>
</author>
<published>2025-04-25T09:50:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=adbb39eca39d11cc7bd512ac36d2130213c1d58c'/>
<id>adbb39eca39d11cc7bd512ac36d2130213c1d58c</id>
<content type='text'>
[ Upstream commit 548762f05d19c5542db7590bcdfb9be1fb928376 ]

When building the latest samples/bpf on LoongArch Fedora

     make M=samples/bpf

There are compilation errors as follows:

In file included from ./linux/samples/bpf/sockex2_kern.c:2:
In file included from ./include/uapi/linux/in.h:25:
In file included from ./include/linux/socket.h:8:
In file included from ./include/linux/uio.h:9:
In file included from ./include/linux/thread_info.h:60:
In file included from ./arch/loongarch/include/asm/thread_info.h:15:
In file included from ./arch/loongarch/include/asm/processor.h:13:
In file included from ./arch/loongarch/include/asm/cpu-info.h:11:
./arch/loongarch/include/asm/loongarch.h:13:10: fatal error: 'larchintrin.h' file not found
         ^~~~~~~~~~~~~~~
1 error generated.

larchintrin.h is included in /usr/lib64/clang/14.0.6/include,
and the header file location is specified at compile time.

Test on LoongArch Fedora:
https://github.com/fedora-remix-loongarch/releases-info

Signed-off-by: Haoran Jiang &lt;jianghaoran@kylinos.cn&gt;
Signed-off-by: zhangxi &lt;zhangxi@kylinos.cn&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250425095042.838824-1-jianghaoran@kylinos.cn
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 548762f05d19c5542db7590bcdfb9be1fb928376 ]

When building the latest samples/bpf on LoongArch Fedora

     make M=samples/bpf

There are compilation errors as follows:

In file included from ./linux/samples/bpf/sockex2_kern.c:2:
In file included from ./include/uapi/linux/in.h:25:
In file included from ./include/linux/socket.h:8:
In file included from ./include/linux/uio.h:9:
In file included from ./include/linux/thread_info.h:60:
In file included from ./arch/loongarch/include/asm/thread_info.h:15:
In file included from ./arch/loongarch/include/asm/processor.h:13:
In file included from ./arch/loongarch/include/asm/cpu-info.h:11:
./arch/loongarch/include/asm/loongarch.h:13:10: fatal error: 'larchintrin.h' file not found
         ^~~~~~~~~~~~~~~
1 error generated.

larchintrin.h is included in /usr/lib64/clang/14.0.6/include,
and the header file location is specified at compile time.

Test on LoongArch Fedora:
https://github.com/fedora-remix-loongarch/releases-info

Signed-off-by: Haoran Jiang &lt;jianghaoran@kylinos.cn&gt;
Signed-off-by: zhangxi &lt;zhangxi@kylinos.cn&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20250425095042.838824-1-jianghaoran@kylinos.cn
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples/bpf: Fix a resource leak</title>
<updated>2024-12-14T19:00:03+00:00</updated>
<author>
<name>Zhu Jun</name>
<email>zhujun2@cmss.chinamobile.com</email>
</author>
<published>2024-10-10T01:41:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=cf27f38254db7de703071c1dea3335dbc06f0f71'/>
<id>cf27f38254db7de703071c1dea3335dbc06f0f71</id>
<content type='text'>
[ Upstream commit f3ef53174b23246fe9bc2bbc2542f3a3856fa1e2 ]

The opened file should be closed in show_sockopts(), otherwise resource
leak will occur that this problem was discovered by reading code

Signed-off-by: Zhu Jun &lt;zhujun2@cmss.chinamobile.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20241010014126.2573-1-zhujun2@cmss.chinamobile.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit f3ef53174b23246fe9bc2bbc2542f3a3856fa1e2 ]

The opened file should be closed in show_sockopts(), otherwise resource
leak will occur that this problem was discovered by reading code

Signed-off-by: Zhu Jun &lt;zhujun2@cmss.chinamobile.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20241010014126.2573-1-zhujun2@cmss.chinamobile.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Fix the xdp_adjust_tail sample prog issue</title>
<updated>2024-12-09T09:32:02+00:00</updated>
<author>
<name>Yuan Chen</name>
<email>chenyuan@kylinos.cn</email>
</author>
<published>2024-09-30T02:41:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=e05f60981951752cc849845136f9886fc43e2201'/>
<id>e05f60981951752cc849845136f9886fc43e2201</id>
<content type='text'>
[ Upstream commit 4236f114a3ffbbfd217436c08852e94cae372f57 ]

During the xdp_adjust_tail test, probabilistic failure occurs and SKB package
is discarded by the kernel. After checking the issues by tracking SKB package,
it is identified that they were caused by checksum errors. Refer to checksum
of the arch/arm64/include/asm/checksum.h for fixing.

v2: Based on Alexei Starovoitov's suggestions, it is necessary to keep the code
 implementation consistent.

Fixes: c6ffd1ff7856 (bpf: add bpf_xdp_adjust_tail sample prog)
Signed-off-by: Yuan Chen &lt;chenyuan@kylinos.cn&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20240930024115.52841-1-chenyuan_fl@163.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 4236f114a3ffbbfd217436c08852e94cae372f57 ]

During the xdp_adjust_tail test, probabilistic failure occurs and SKB package
is discarded by the kernel. After checking the issues by tracking SKB package,
it is identified that they were caused by checksum errors. Refer to checksum
of the arch/arm64/include/asm/checksum.h for fixing.

v2: Based on Alexei Starovoitov's suggestions, it is necessary to keep the code
 implementation consistent.

Fixes: c6ffd1ff7856 (bpf: add bpf_xdp_adjust_tail sample prog)
Signed-off-by: Yuan Chen &lt;chenyuan@kylinos.cn&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20240930024115.52841-1-chenyuan_fl@163.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples/bpf: Fix compilation errors with cf-protection option</title>
<updated>2024-10-04T14:29:19+00:00</updated>
<author>
<name>Jiangshan Yi</name>
<email>yijiangshan@kylinos.cn</email>
</author>
<published>2024-08-15T13:55:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=fc2b89707e478ccc7127e59bb202dc847c8918f8'/>
<id>fc2b89707e478ccc7127e59bb202dc847c8918f8</id>
<content type='text'>
[ Upstream commit fdf1c728fac541891ef1aa773bfd42728626769c ]

Currently, compiling the bpf programs will result the compilation errors
with the cf-protection option as follows in arm64 and loongarch64 machine
when using gcc 12.3.1 and clang 17.0.6. This commit fixes the compilation
errors by limited the cf-protection option only used in x86 platform.

[root@localhost linux]# make M=samples/bpf
	......
  CLANG-bpf  samples/bpf/xdp2skb_meta_kern.o
error: option 'cf-protection=return' cannot be specified on this target
error: option 'cf-protection=branch' cannot be specified on this target
2 errors generated.
  CLANG-bpf  samples/bpf/syscall_tp_kern.o
error: option 'cf-protection=return' cannot be specified on this target
error: option 'cf-protection=branch' cannot be specified on this target
2 errors generated.
	......

Fixes: 34f6e38f58db ("samples/bpf: fix warning with ignored-attributes")
Reported-by: Jiangshan Yi &lt;yijiangshan@kylinos.cn&gt;
Signed-off-by: Jiangshan Yi &lt;yijiangshan@kylinos.cn&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Tested-by: Qiang Wang &lt;wangqiang1@kylinos.cn&gt;
Link: https://lore.kernel.org/bpf/20240815135524.140675-1-13667453960@163.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fdf1c728fac541891ef1aa773bfd42728626769c ]

Currently, compiling the bpf programs will result the compilation errors
with the cf-protection option as follows in arm64 and loongarch64 machine
when using gcc 12.3.1 and clang 17.0.6. This commit fixes the compilation
errors by limited the cf-protection option only used in x86 platform.

[root@localhost linux]# make M=samples/bpf
	......
  CLANG-bpf  samples/bpf/xdp2skb_meta_kern.o
error: option 'cf-protection=return' cannot be specified on this target
error: option 'cf-protection=branch' cannot be specified on this target
2 errors generated.
  CLANG-bpf  samples/bpf/syscall_tp_kern.o
error: option 'cf-protection=return' cannot be specified on this target
error: option 'cf-protection=branch' cannot be specified on this target
2 errors generated.
	......

Fixes: 34f6e38f58db ("samples/bpf: fix warning with ignored-attributes")
Reported-by: Jiangshan Yi &lt;yijiangshan@kylinos.cn&gt;
Signed-off-by: Jiangshan Yi &lt;yijiangshan@kylinos.cn&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Tested-by: Qiang Wang &lt;wangqiang1@kylinos.cn&gt;
Link: https://lore.kernel.org/bpf/20240815135524.140675-1-13667453960@163.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Replace bpf_lpm_trie_key 0-length array with flexible array</title>
<updated>2024-08-19T04:04:27+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2024-02-22T15:56:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=ef33f0296893356314a5c79e787bca977bb3c9ec'/>
<id>ef33f0296893356314a5c79e787bca977bb3c9ec</id>
<content type='text'>
[ 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 *)&amp;key-&gt;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 *)&amp;node-&gt;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 &amp; 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 &lt;mark.rutland@arm.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
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 &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ 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 *)&amp;key-&gt;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 *)&amp;node-&gt;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 &amp; 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 &lt;mark.rutland@arm.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
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 &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>work around gcc bugs with 'asm goto' with outputs</title>
<updated>2024-02-23T08:24:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-02-09T20:39:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=aaff74d886d08d0708f8d316ef09b5b4bd9dd7c1'/>
<id>aaff74d886d08d0708f8d316ef09b5b4bd9dd7c1</id>
<content type='text'>
commit 4356e9f841f7fbb945521cef3577ba394c65f3fc upstream.

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

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

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

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

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

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

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

 (b) Internal compiler errors:

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

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

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

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

Reported-and-tested-by: Sean Christopherson &lt;seanjc@google.com&gt;
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Uros Bizjak &lt;ubizjak@gmail.com&gt;
Cc: Jakub Jelinek &lt;jakub@redhat.com&gt;
Cc: Andrew Pinski &lt;quic_apinski@quicinc.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 4356e9f841f7fbb945521cef3577ba394c65f3fc upstream.

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

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

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

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

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

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

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

 (b) Internal compiler errors:

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

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

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

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

Reported-and-tested-by: Sean Christopherson &lt;seanjc@google.com&gt;
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Uros Bizjak &lt;ubizjak@gmail.com&gt;
Cc: Jakub Jelinek &lt;jakub@redhat.com&gt;
Cc: Andrew Pinski &lt;quic_apinski@quicinc.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples/bpf: syscall_tp_user: Fix array out-of-bound access</title>
<updated>2023-11-28T17:19:48+00:00</updated>
<author>
<name>Jinghao Jia</name>
<email>jinghao@linux.ibm.com</email>
</author>
<published>2023-09-17T21:42:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=de4825a444560f8cb78b03dda3ba873fab88bc4f'/>
<id>de4825a444560f8cb78b03dda3ba873fab88bc4f</id>
<content type='text'>
[ Upstream commit 9220c3ef6fefbf18f24aeedb1142a642b3de0596 ]

Commit 06744f24696e ("samples/bpf: Add openat2() enter/exit tracepoint
to syscall_tp sample") added two more eBPF programs to support the
openat2() syscall. However, it did not increase the size of the array
that holds the corresponding bpf_links. This leads to an out-of-bound
access on that array in the bpf_object__for_each_program loop and could
corrupt other variables on the stack. On our testing QEMU, it corrupts
the map1_fds array and causes the sample to fail:

  # ./syscall_tp
  prog #0: map ids 4 5
  verify map:4 val: 5
  map_lookup failed: Bad file descriptor

Dynamically allocate the array based on the number of programs reported
by libbpf to prevent similar inconsistencies in the future

Fixes: 06744f24696e ("samples/bpf: Add openat2() enter/exit tracepoint to syscall_tp sample")
Signed-off-by: Jinghao Jia &lt;jinghao@linux.ibm.com&gt;
Signed-off-by: Ruowen Qin &lt;ruowenq2@illinois.edu&gt;
Signed-off-by: Jinghao Jia &lt;jinghao7@illinois.edu&gt;
Link: https://lore.kernel.org/r/20230917214220.637721-4-jinghao7@illinois.edu
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 9220c3ef6fefbf18f24aeedb1142a642b3de0596 ]

Commit 06744f24696e ("samples/bpf: Add openat2() enter/exit tracepoint
to syscall_tp sample") added two more eBPF programs to support the
openat2() syscall. However, it did not increase the size of the array
that holds the corresponding bpf_links. This leads to an out-of-bound
access on that array in the bpf_object__for_each_program loop and could
corrupt other variables on the stack. On our testing QEMU, it corrupts
the map1_fds array and causes the sample to fail:

  # ./syscall_tp
  prog #0: map ids 4 5
  verify map:4 val: 5
  map_lookup failed: Bad file descriptor

Dynamically allocate the array based on the number of programs reported
by libbpf to prevent similar inconsistencies in the future

Fixes: 06744f24696e ("samples/bpf: Add openat2() enter/exit tracepoint to syscall_tp sample")
Signed-off-by: Jinghao Jia &lt;jinghao@linux.ibm.com&gt;
Signed-off-by: Ruowen Qin &lt;ruowenq2@illinois.edu&gt;
Signed-off-by: Jinghao Jia &lt;jinghao7@illinois.edu&gt;
Link: https://lore.kernel.org/r/20230917214220.637721-4-jinghao7@illinois.edu
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples/bpf: syscall_tp_user: Rename num_progs into nr_tests</title>
<updated>2023-11-28T17:19:48+00:00</updated>
<author>
<name>Jinghao Jia</name>
<email>jinghao@linux.ibm.com</email>
</author>
<published>2023-09-17T21:42:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=948189f679ac9820c57c7801d592442b7d122972'/>
<id>948189f679ac9820c57c7801d592442b7d122972</id>
<content type='text'>
[ Upstream commit 0ee352fe0d28015cab161b04d202fa3231c0ba3b ]

The variable name num_progs causes confusion because that variable
really controls the number of rounds the test should be executed.

Rename num_progs into nr_tests for the sake of clarity.

Signed-off-by: Jinghao Jia &lt;jinghao@linux.ibm.com&gt;
Signed-off-by: Ruowen Qin &lt;ruowenq2@illinois.edu&gt;
Signed-off-by: Jinghao Jia &lt;jinghao7@illinois.edu&gt;
Link: https://lore.kernel.org/r/20230917214220.637721-3-jinghao7@illinois.edu
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Stable-dep-of: 9220c3ef6fef ("samples/bpf: syscall_tp_user: Fix array out-of-bound access")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 0ee352fe0d28015cab161b04d202fa3231c0ba3b ]

The variable name num_progs causes confusion because that variable
really controls the number of rounds the test should be executed.

Rename num_progs into nr_tests for the sake of clarity.

Signed-off-by: Jinghao Jia &lt;jinghao@linux.ibm.com&gt;
Signed-off-by: Ruowen Qin &lt;ruowenq2@illinois.edu&gt;
Signed-off-by: Jinghao Jia &lt;jinghao7@illinois.edu&gt;
Link: https://lore.kernel.org/r/20230917214220.637721-3-jinghao7@illinois.edu
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Stable-dep-of: 9220c3ef6fef ("samples/bpf: syscall_tp_user: Fix array out-of-bound access")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples/bpf: Add note to README about the XDP utilities moved to xdp-tools</title>
<updated>2023-08-24T15:43:50+00:00</updated>
<author>
<name>Toke Høiland-Jørgensen</name>
<email>toke@redhat.com</email>
</author>
<published>2023-08-24T10:22:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=5a9fd0f778ebb2076fa1098df23e741c794d9992'/>
<id>5a9fd0f778ebb2076fa1098df23e741c794d9992</id>
<content type='text'>
To help users find the XDP utilities, add a note to the README about the
new location and the conversion documentation in the commit messages.

Signed-off-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Link: https://lore.kernel.org/r/20230824102255.1561885-8-toke@redhat.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
To help users find the XDP utilities, add a note to the README about the
new location and the conversion documentation in the commit messages.

Signed-off-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Link: https://lore.kernel.org/r/20230824102255.1561885-8-toke@redhat.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples/bpf: Cleanup .gitignore</title>
<updated>2023-08-24T15:43:50+00:00</updated>
<author>
<name>Toke Høiland-Jørgensen</name>
<email>toke@redhat.com</email>
</author>
<published>2023-08-24T10:22:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=91b965136d536a981ed22097bc2b72625f5c4211'/>
<id>91b965136d536a981ed22097bc2b72625f5c4211</id>
<content type='text'>
Remove no longer present XDP utilities from .gitignore. Apart from the
recently removed XDP utilities this also includes the previously removed
xdpsock and xsk utilities.

Signed-off-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Link: https://lore.kernel.org/r/20230824102255.1561885-7-toke@redhat.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove no longer present XDP utilities from .gitignore. Apart from the
recently removed XDP utilities this also includes the previously removed
xdpsock and xsk utilities.

Signed-off-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Link: https://lore.kernel.org/r/20230824102255.1561885-7-toke@redhat.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
