[PATCH bpf-next v2] bpf, mips: Fix build errors about __NR_bpf undeclared

Subsystems: bpf [general] (safe dynamic programs and tools), bpf [library] (libbpf), the rest

STALE1716d LANDED

Landed in mainline as e32cb12ff52a on 2021-11-26.

4 messages, 4 authors, 2021-11-26 · open the first message on its own page

[PATCH bpf-next v2] bpf, mips: Fix build errors about __NR_bpf undeclared

From: Tiezhu Yang <yangtiezhu@loongson.cn>
Date: 2021-11-25 01:38:15 

Add the __NR_bpf definitions to fix the following build errors for mips.

 $ cd tools/bpf/bpftool
 $ make
 [...]
 bpf.c:54:4: error: #error __NR_bpf not defined. libbpf does not support your arch.
  #  error __NR_bpf not defined. libbpf does not support your arch.
     ^~~~~
 bpf.c: In function ‘sys_bpf’:
 bpf.c:66:17: error: ‘__NR_bpf’ undeclared (first use in this function); did you mean ‘__NR_brk’?
   return syscall(__NR_bpf, cmd, attr, size);
                  ^~~~~~~~
                  __NR_brk
 [...]
 In file included from gen_loader.c:15:0:
 skel_internal.h: In function ‘skel_sys_bpf’:
 skel_internal.h:53:17: error: ‘__NR_bpf’ undeclared (first use in this function); did you mean ‘__NR_brk’?
   return syscall(__NR_bpf, cmd, attr, size);
                  ^~~~~~~~
                  __NR_brk

We can see the following generated definitions:

 $ grep -r "#define __NR_bpf" arch/mips
 arch/mips/include/generated/uapi/asm/unistd_o32.h:#define __NR_bpf (__NR_Linux + 355)
 arch/mips/include/generated/uapi/asm/unistd_n64.h:#define __NR_bpf (__NR_Linux + 315)
 arch/mips/include/generated/uapi/asm/unistd_n32.h:#define __NR_bpf (__NR_Linux + 319)

The __NR_Linux is defined in arch/mips/include/uapi/asm/unistd.h:

 $ grep -r "#define __NR_Linux" arch/mips
 arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux	4000
 arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux	5000
 arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux	6000

That is to say, __NR_bpf is
4000 + 355 = 4355 for mips o32,
6000 + 319 = 6319 for mips n32,
5000 + 315 = 5315 for mips n64.

So use the GCC pre-defined macro _ABIO32, _ABIN32 and _ABI64 [1] to define
the corresponding __NR_bpf.

This patch is similar with commit bad1926dd2f6 ("bpf, s390: fix build for
libbpf and selftest suite").

[1] https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config/mips/mips.h#l549

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---

v2: use a final number without __NR_Linux to define __NR_bpf
    suggested by Andrii Nakryiko, thank you.

 tools/build/feature/test-bpf.c |  6 ++++++
 tools/lib/bpf/bpf.c            |  6 ++++++
 tools/lib/bpf/skel_internal.h  | 10 ++++++++++
 3 files changed, 22 insertions(+)

diff --git a/tools/build/feature/test-bpf.c b/tools/build/feature/test-bpf.c
index 82070ea..727d22e 100644
--- a/tools/build/feature/test-bpf.c
+++ b/tools/build/feature/test-bpf.c
@@ -14,6 +14,12 @@
 #  define __NR_bpf 349
 # elif defined(__s390__)
 #  define __NR_bpf 351
+# elif defined(__mips__) && defined(_ABIO32)
+#  define __NR_bpf 4355
+# elif defined(__mips__) && defined(_ABIN32)
+#  define __NR_bpf 6319
+# elif defined(__mips__) && defined(_ABI64)
+#  define __NR_bpf 5315
 # else
 #  error __NR_bpf not defined. libbpf does not support your arch.
 # endif
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 94560ba..17f9fe2 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -50,6 +50,12 @@
 #  define __NR_bpf 351
 # elif defined(__arc__)
 #  define __NR_bpf 280
+# elif defined(__mips__) && defined(_ABIO32)
+#  define __NR_bpf 4355
+# elif defined(__mips__) && defined(_ABIN32)
+#  define __NR_bpf 6319
+# elif defined(__mips__) && defined(_ABI64)
+#  define __NR_bpf 5315
 # else
 #  error __NR_bpf not defined. libbpf does not support your arch.
 # endif
diff --git a/tools/lib/bpf/skel_internal.h b/tools/lib/bpf/skel_internal.h
index 9cf6670..064da66 100644
--- a/tools/lib/bpf/skel_internal.h
+++ b/tools/lib/bpf/skel_internal.h
@@ -7,6 +7,16 @@
 #include <sys/syscall.h>
 #include <sys/mman.h>
 
+#ifndef __NR_bpf
+# if defined(__mips__) && defined(_ABIO32)
+#  define __NR_bpf 4355
+# elif defined(__mips__) && defined(_ABIN32)
+#  define __NR_bpf 6319
+# elif defined(__mips__) && defined(_ABI64)
+#  define __NR_bpf 5315
+# endif
+#endif
+
 /* This file is a base header for auto-generated *.lskel.h files.
  * Its contents will change and may become part of auto-generation in the future.
  *
-- 
2.1.0

Re: [PATCH bpf-next v2] bpf, mips: Fix build errors about __NR_bpf undeclared

From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2021-11-25 23:07:46 

[ +Johan ]

On 11/25/21 2:36 AM, Tiezhu Yang wrote:
quoted hunk
Add the __NR_bpf definitions to fix the following build errors for mips.

  $ cd tools/bpf/bpftool
  $ make
  [...]
  bpf.c:54:4: error: #error __NR_bpf not defined. libbpf does not support your arch.
   #  error __NR_bpf not defined. libbpf does not support your arch.
      ^~~~~
  bpf.c: In function ‘sys_bpf’:
  bpf.c:66:17: error: ‘__NR_bpf’ undeclared (first use in this function); did you mean ‘__NR_brk’?
    return syscall(__NR_bpf, cmd, attr, size);
                   ^~~~~~~~
                   __NR_brk
  [...]
  In file included from gen_loader.c:15:0:
  skel_internal.h: In function ‘skel_sys_bpf’:
  skel_internal.h:53:17: error: ‘__NR_bpf’ undeclared (first use in this function); did you mean ‘__NR_brk’?
    return syscall(__NR_bpf, cmd, attr, size);
                   ^~~~~~~~
                   __NR_brk

We can see the following generated definitions:

  $ grep -r "#define __NR_bpf" arch/mips
  arch/mips/include/generated/uapi/asm/unistd_o32.h:#define __NR_bpf (__NR_Linux + 355)
  arch/mips/include/generated/uapi/asm/unistd_n64.h:#define __NR_bpf (__NR_Linux + 315)
  arch/mips/include/generated/uapi/asm/unistd_n32.h:#define __NR_bpf (__NR_Linux + 319)

The __NR_Linux is defined in arch/mips/include/uapi/asm/unistd.h:

  $ grep -r "#define __NR_Linux" arch/mips
  arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux	4000
  arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux	5000
  arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux	6000

That is to say, __NR_bpf is
4000 + 355 = 4355 for mips o32,
6000 + 319 = 6319 for mips n32,
5000 + 315 = 5315 for mips n64.

So use the GCC pre-defined macro _ABIO32, _ABIN32 and _ABI64 [1] to define
the corresponding __NR_bpf.

This patch is similar with commit bad1926dd2f6 ("bpf, s390: fix build for
libbpf and selftest suite").

[1] https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config/mips/mips.h#l549

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---

v2: use a final number without __NR_Linux to define __NR_bpf
     suggested by Andrii Nakryiko, thank you.

  tools/build/feature/test-bpf.c |  6 ++++++
  tools/lib/bpf/bpf.c            |  6 ++++++
  tools/lib/bpf/skel_internal.h  | 10 ++++++++++
  3 files changed, 22 insertions(+)

diff --git a/tools/build/feature/test-bpf.c b/tools/build/feature/test-bpf.c
index 82070ea..727d22e 100644
--- a/tools/build/feature/test-bpf.c
+++ b/tools/build/feature/test-bpf.c
@@ -14,6 +14,12 @@
  #  define __NR_bpf 349
  # elif defined(__s390__)
  #  define __NR_bpf 351
+# elif defined(__mips__) && defined(_ABIO32)
+#  define __NR_bpf 4355
+# elif defined(__mips__) && defined(_ABIN32)
+#  define __NR_bpf 6319
+# elif defined(__mips__) && defined(_ABI64)
+#  define __NR_bpf 5315
  # else
  #  error __NR_bpf not defined. libbpf does not support your arch.
  # endif
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 94560ba..17f9fe2 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -50,6 +50,12 @@
  #  define __NR_bpf 351
  # elif defined(__arc__)
  #  define __NR_bpf 280
+# elif defined(__mips__) && defined(_ABIO32)
+#  define __NR_bpf 4355
+# elif defined(__mips__) && defined(_ABIN32)
+#  define __NR_bpf 6319
+# elif defined(__mips__) && defined(_ABI64)
+#  define __NR_bpf 5315
  # else
  #  error __NR_bpf not defined. libbpf does not support your arch.
  # endif
diff --git a/tools/lib/bpf/skel_internal.h b/tools/lib/bpf/skel_internal.h
index 9cf6670..064da66 100644
--- a/tools/lib/bpf/skel_internal.h
+++ b/tools/lib/bpf/skel_internal.h
@@ -7,6 +7,16 @@
  #include <sys/syscall.h>
  #include <sys/mman.h>
  
+#ifndef __NR_bpf
+# if defined(__mips__) && defined(_ABIO32)
+#  define __NR_bpf 4355
+# elif defined(__mips__) && defined(_ABIN32)
+#  define __NR_bpf 6319
+# elif defined(__mips__) && defined(_ABI64)
+#  define __NR_bpf 5315
+# endif
+#endif
Bit unfortunate that mips is the only arch where we run into this apparently? :/
Given we also redefine a skel_sys_bpf(), maybe libbpf should just provide something
like a `LIBBPF_API int libbpf_sys_bpf(enum bpf_cmd cmd, [...])` so we rely implicitly
only on the libbpf-internal __NR_bpf instead of duplicating again?

  /* This file is a base header for auto-generated *.lskel.h files.
   * Its contents will change and may become part of auto-generation in the future.
   *





  

    
Re: [PATCH bpf-next v2] bpf, mips: Fix build errors about __NR_bpf undeclared

    

      From: Andrii Nakryiko <hidden>

      Date: 2021-11-26 01:24:29 
    

  

  
On Thu, Nov 25, 2021 at 3:05 PM Daniel Borkmann [off-list ref] wrote:
[ +Johan ]

On 11/25/21 2:36 AM, Tiezhu Yang wrote:
quoted
Add the __NR_bpf definitions to fix the following build errors for mips.

  $ cd tools/bpf/bpftool
  $ make
  [...]
  bpf.c:54:4: error: #error __NR_bpf not defined. libbpf does not support your arch.
   #  error __NR_bpf not defined. libbpf does not support your arch.
      ^~~~~
  bpf.c: In function ‘sys_bpf’:
  bpf.c:66:17: error: ‘__NR_bpf’ undeclared (first use in this function); did you mean ‘__NR_brk’?
    return syscall(__NR_bpf, cmd, attr, size);
                   ^~~~~~~~
                   __NR_brk
  [...]
  In file included from gen_loader.c:15:0:
  skel_internal.h: In function ‘skel_sys_bpf’:
  skel_internal.h:53:17: error: ‘__NR_bpf’ undeclared (first use in this function); did you mean ‘__NR_brk’?
    return syscall(__NR_bpf, cmd, attr, size);
                   ^~~~~~~~
                   __NR_brk

We can see the following generated definitions:

  $ grep -r "#define __NR_bpf" arch/mips
  arch/mips/include/generated/uapi/asm/unistd_o32.h:#define __NR_bpf (__NR_Linux + 355)
  arch/mips/include/generated/uapi/asm/unistd_n64.h:#define __NR_bpf (__NR_Linux + 315)
  arch/mips/include/generated/uapi/asm/unistd_n32.h:#define __NR_bpf (__NR_Linux + 319)

The __NR_Linux is defined in arch/mips/include/uapi/asm/unistd.h:

  $ grep -r "#define __NR_Linux" arch/mips
  arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux      4000
  arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux      5000
  arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux      6000

That is to say, __NR_bpf is
4000 + 355 = 4355 for mips o32,
6000 + 319 = 6319 for mips n32,
5000 + 315 = 5315 for mips n64.

So use the GCC pre-defined macro _ABIO32, _ABIN32 and _ABI64 [1] to define
the corresponding __NR_bpf.

This patch is similar with commit bad1926dd2f6 ("bpf, s390: fix build for
libbpf and selftest suite").

[1] https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config/mips/mips.h#l549

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---

v2: use a final number without __NR_Linux to define __NR_bpf
     suggested by Andrii Nakryiko, thank you.

  tools/build/feature/test-bpf.c |  6 ++++++
  tools/lib/bpf/bpf.c            |  6 ++++++
  tools/lib/bpf/skel_internal.h  | 10 ++++++++++
  3 files changed, 22 insertions(+)

diff --git a/tools/build/feature/test-bpf.c b/tools/build/feature/test-bpf.c
index 82070ea..727d22e 100644
--- a/tools/build/feature/test-bpf.c
+++ b/tools/build/feature/test-bpf.c
@@ -14,6 +14,12 @@
  #  define __NR_bpf 349
  # elif defined(__s390__)
  #  define __NR_bpf 351
+# elif defined(__mips__) && defined(_ABIO32)
+#  define __NR_bpf 4355
+# elif defined(__mips__) && defined(_ABIN32)
+#  define __NR_bpf 6319
+# elif defined(__mips__) && defined(_ABI64)
+#  define __NR_bpf 5315
  # else
  #  error __NR_bpf not defined. libbpf does not support your arch.
  # endif
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 94560ba..17f9fe2 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -50,6 +50,12 @@
  #  define __NR_bpf 351
  # elif defined(__arc__)
  #  define __NR_bpf 280
+# elif defined(__mips__) && defined(_ABIO32)
+#  define __NR_bpf 4355
+# elif defined(__mips__) && defined(_ABIN32)
+#  define __NR_bpf 6319
+# elif defined(__mips__) && defined(_ABI64)
+#  define __NR_bpf 5315
  # else
  #  error __NR_bpf not defined. libbpf does not support your arch.
  # endif
diff --git a/tools/lib/bpf/skel_internal.h b/tools/lib/bpf/skel_internal.h
index 9cf6670..064da66 100644
--- a/tools/lib/bpf/skel_internal.h
+++ b/tools/lib/bpf/skel_internal.h
@@ -7,6 +7,16 @@
  #include <sys/syscall.h>
  #include <sys/mman.h>

+#ifndef __NR_bpf
+# if defined(__mips__) && defined(_ABIO32)
+#  define __NR_bpf 4355
+# elif defined(__mips__) && defined(_ABIN32)
+#  define __NR_bpf 6319
+# elif defined(__mips__) && defined(_ABI64)
+#  define __NR_bpf 5315
+# endif
+#endif
Bit unfortunate that mips is the only arch where we run into this apparently? :/
Given we also redefine a skel_sys_bpf(), maybe libbpf should just provide something
like a `LIBBPF_API int libbpf_sys_bpf(enum bpf_cmd cmd, [...])` so we rely implicitly
only on the libbpf-internal __NR_bpf instead of duplicating again?
Unfortunately the point of skel_internal.h is to not depend on libbpf
APIs. I think for now it should be fine to have this duplication (not
that those numbers are going to change ever) and we can improve this
later.

quoted
  /* This file is a base header for auto-generated *.lskel.h files.
   * Its contents will change and may become part of auto-generation in the future.
   *





  

    
Re: [PATCH bpf-next v2] bpf, mips: Fix build errors about __NR_bpf undeclared

    

      From: patchwork-bot+netdevbpf@kernel.org

      Date: 2021-11-26 21:22:11 
    

  

  
Hello:

This patch was applied to bpf/bpf-next.git (master)
by Daniel Borkmann [off-list ref]:

On Thu, 25 Nov 2021 09:36:07 +0800 you wrote:
Add the __NR_bpf definitions to fix the following build errors for mips.

 $ cd tools/bpf/bpftool
 $ make
 [...]
 bpf.c:54:4: error: #error __NR_bpf not defined. libbpf does not support your arch.
  #  error __NR_bpf not defined. libbpf does not support your arch.
     ^~~~~
 bpf.c: In function ‘sys_bpf’:
 bpf.c:66:17: error: ‘__NR_bpf’ undeclared (first use in this function); did you mean ‘__NR_brk’?
   return syscall(__NR_bpf, cmd, attr, size);
                  ^~~~~~~~
                  __NR_brk
 [...]
 In file included from gen_loader.c:15:0:
 skel_internal.h: In function ‘skel_sys_bpf’:
 skel_internal.h:53:17: error: ‘__NR_bpf’ undeclared (first use in this function); did you mean ‘__NR_brk’?
   return syscall(__NR_bpf, cmd, attr, size);
                  ^~~~~~~~
                  __NR_brk

[...]
Here is the summary with links:
  - [bpf-next,v2] bpf, mips: Fix build errors about __NR_bpf undeclared
    https://git.kernel.org/bpf/bpf-next/c/e32cb12ff52a

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html






    
  

  
    

      

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