[PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

Subsystems: bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest

STALE1736d

10 messages, 4 authors, 2022-01-06 · open the first message on its own page

[PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

From: Tyler Wear <hidden>
Date: 2021-12-22 02:29:03

Need to modify the ds field to support upcoming
Wifi QoS Alliance spec. Instead of adding generic
function for just modifying the ds field, add
skb_store_bytes for BPF_PROG_TYPE_CGROUP_SKB. This
allows other fields in the network and transport header
to be modified in the future.

Signed-off-by: Tyler Wear <redacted>
---
 net/core/filter.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c
index 6102f093d59a..0c25aa2212a2 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c

@@ -7289,6 +7289,8 @@ static const struct bpf_func_proto *
 cg_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
 	switch (func_id) {
+	case BPF_FUNC_skb_store_bytes:
+		return &bpf_skb_store_bytes_proto;
 	case BPF_FUNC_get_local_storage:
 		return &bpf_get_local_storage_proto;
 	case BPF_FUNC_sk_fullsock:

-- 
2.17.1

Re: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

From: Yonghong Song <hidden>
Date: 2021-12-22 03:44:04


On 12/21/21 6:27 PM, Tyler Wear wrote:

Need to modify the ds field to support upcoming
Wifi QoS Alliance spec. Instead of adding generic
function for just modifying the ds field, add
skb_store_bytes for BPF_PROG_TYPE_CGROUP_SKB. This
allows other fields in the network and transport header
to be modified in the future.

Could change tag from "[PATCH]" to "[PATCH bpf-next]"?
Please also indicate the version of the patch, so in
this case, it should be "[PATCH bpf-next v2]".

I think you can add more contents in the commit
message about why existing bpf_setsockopt() won't work
and why CGROUP_UDP[4|6]_SENDMSG is not preferred.
These have been discussed in v1 of this patch and they
are valuable for people to understand full context
and reasoning.

quoted hunk

Signed-off-by: Tyler Wear <redacted>
---
  net/core/filter.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c
index 6102f093d59a..0c25aa2212a2 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c

@@ -7289,6 +7289,8 @@ static const struct bpf_func_proto *
  cg_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
  {
  	switch (func_id) {
+	case BPF_FUNC_skb_store_bytes:
+		return &bpf_skb_store_bytes_proto;

Typically different 'case's are added in chronological order to people
can guess what is added earlier and what is added later. Maybe add
the new helper after BPF_FUNC_perf_event_output?

  	case BPF_FUNC_get_local_storage:
  		return &bpf_get_local_storage_proto;
  	case BPF_FUNC_sk_fullsock:

Please add a test case to exercise the new usage of bpf_skb_store_bytes() helper. You may piggy back on
some existing cg_skb progs if it is easier to do.

RE: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

From: Tyler Wear <hidden>
Date: 2021-12-22 22:49:49

On 12/21/21 6:27 PM, Tyler Wear wrote:

quoted

Need to modify the ds field to support upcoming Wifi QoS Alliance
spec. Instead of adding generic function for just modifying the ds
field, add skb_store_bytes for BPF_PROG_TYPE_CGROUP_SKB. This allows
other fields in the network and transport header to be modified in the
future.

Could change tag from "[PATCH]" to "[PATCH bpf-next]"?
Please also indicate the version of the patch, so in this case, it should be "[PATCH bpf-next v2]".

I think you can add more contents in the commit message about why existing bpf_setsockopt() won't work and why
CGROUP_UDP[4|6]_SENDMSG is not preferred.
These have been discussed in v1 of this patch and they are valuable for people to understand full context and reasoning.

quoted

Signed-off-by: Tyler Wear <redacted>
---
  net/core/filter.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c index

6102f093d59a..0c25aa2212a2 100644

--- a/net/core/filter.c
+++ b/net/core/filter.c

@@ -7289,6 +7289,8 @@ static const struct bpf_func_proto *
  cg_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
  {
      switch (func_id) {
+     case BPF_FUNC_skb_store_bytes:
+             return &bpf_skb_store_bytes_proto;

Typically different 'case's are added in chronological order to people can guess what is added earlier and what is added later. Maybe
add the new helper after BPF_FUNC_perf_event_output?

quoted

      case BPF_FUNC_get_local_storage:
              return &bpf_get_local_storage_proto;
      case BPF_FUNC_sk_fullsock:

Please add a test case to exercise the new usage of
bpf_skb_store_bytes() helper. You may piggy back on some existing cg_skb progs if it is easier to do.

Would it be sufficient to change the dscp value in tools/testing/selftests/bpf/progs/test_sock_fields.c via bpf_skb_store_bytes()

Re: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

From: Martin KaFai Lau <hidden>
Date: 2021-12-22 23:51:05

On Wed, Dec 22, 2021 at 10:49:45PM +0000, Tyler Wear wrote:

quoted

On 12/21/21 6:27 PM, Tyler Wear wrote:

quoted

Need to modify the ds field to support upcoming Wifi QoS Alliance
spec. Instead of adding generic function for just modifying the ds
field, add skb_store_bytes for BPF_PROG_TYPE_CGROUP_SKB. This allows
other fields in the network and transport header to be modified in the
future.

Could change tag from "[PATCH]" to "[PATCH bpf-next]"?
Please also indicate the version of the patch, so in this case, it should be "[PATCH bpf-next v2]".

I think you can add more contents in the commit message about why existing bpf_setsockopt() won't work and why
CGROUP_UDP[4|6]_SENDMSG is not preferred.
These have been discussed in v1 of this patch and they are valuable for people to understand full context and reasoning.

quoted

Signed-off-by: Tyler Wear <redacted>
---
  net/core/filter.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c index

6102f093d59a..0c25aa2212a2 100644

--- a/net/core/filter.c
+++ b/net/core/filter.c

@@ -7289,6 +7289,8 @@ static const struct bpf_func_proto *
  cg_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
  {
      switch (func_id) {
+     case BPF_FUNC_skb_store_bytes:
+             return &bpf_skb_store_bytes_proto;

Typically different 'case's are added in chronological order to people can guess what is added earlier and what is added later. Maybe
add the new helper after BPF_FUNC_perf_event_output?

quoted

      case BPF_FUNC_get_local_storage:
              return &bpf_get_local_storage_proto;
      case BPF_FUNC_sk_fullsock:

Please add a test case to exercise the new usage of
bpf_skb_store_bytes() helper. You may piggy back on some existing cg_skb progs if it is easier to do.

Would it be sufficient to change the dscp value in tools/testing/selftests/bpf/progs/test_sock_fields.c via bpf_skb_store_bytes()

test_sock_fields focus on sk instead of skb, so it will not be a good fit.

load_bytes_relative.c may be a better fit.
The minimal is to write the dscp value by bpf_skb_store_bytes()
and be able to read it back at the receiver side (e.g.
by making a TCP connection like load_bytes_relative).

RE: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

From: Tyler Wear <hidden>
Date: 2021-12-29 18:29:12

-----Original Message-----
From: Martin KaFai Lau <redacted>
Sent: Wednesday, December 22, 2021 3:51 PM
To: Tyler Wear <redacted>
Cc: Yonghong Song <redacted>; Tyler Wear (QUIC) <redacted>; netdev@vger.kernel.org; bpf@vger.kernel.org;
maze@google.com
Subject: Re: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.

On Wed, Dec 22, 2021 at 10:49:45PM +0000, Tyler Wear wrote:

quoted

On 12/21/21 6:27 PM, Tyler Wear wrote:

quoted

Need to modify the ds field to support upcoming Wifi QoS Alliance
spec. Instead of adding generic function for just modifying the ds
field, add skb_store_bytes for BPF_PROG_TYPE_CGROUP_SKB. This
allows other fields in the network and transport header to be
modified in the future.

Could change tag from "[PATCH]" to "[PATCH bpf-next]"?
Please also indicate the version of the patch, so in this case, it should be "[PATCH bpf-next v2]".

I think you can add more contents in the commit message about why
existing bpf_setsockopt() won't work and why CGROUP_UDP[4|6]_SENDMSG is not preferred.
These have been discussed in v1 of this patch and they are valuable for people to understand full context and reasoning.

quoted

Signed-off-by: Tyler Wear <redacted>
---
  net/core/filter.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c index

6102f093d59a..0c25aa2212a2 100644

--- a/net/core/filter.c
+++ b/net/core/filter.c

@@ -7289,6 +7289,8 @@ static const struct bpf_func_proto *
  cg_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
  {
      switch (func_id) {
+     case BPF_FUNC_skb_store_bytes:
+             return &bpf_skb_store_bytes_proto;

Typically different 'case's are added in chronological order to
people can guess what is added earlier and what is added later. Maybe add the new helper after BPF_FUNC_perf_event_output?

quoted

      case BPF_FUNC_get_local_storage:
              return &bpf_get_local_storage_proto;
      case BPF_FUNC_sk_fullsock:

Please add a test case to exercise the new usage of
bpf_skb_store_bytes() helper. You may piggy back on some existing cg_skb progs if it is easier to do.

Would it be sufficient to change the dscp value in
tools/testing/selftests/bpf/progs/test_sock_fields.c via
bpf_skb_store_bytes()

test_sock_fields focus on sk instead of skb, so it will not be a good fit.

load_bytes_relative.c may be a better fit.
The minimal is to write the dscp value by bpf_skb_store_bytes() and be able to read it back at the receiver side (e.g.
by making a TCP connection like load_bytes_relative).

Unable to run any bpf tests do to errors below. These occur with and without the new patch. Is this a known issue?
Is the new test case required since bpf_skb_store_bytes() is already a tested function for other prog types?

libbpf: failed to find BTF for extern 'bpf_testmod_invalid_mod_kfunc' [18] section: -2
Error: failed to open BPF object file: No such file or directory
libbpf: failed to find BTF info for global/extern symbol 'my_tid'
Error: failed to link '/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/linked_funcs1.o': Unknown error -2 (-2)
libbpf: failed to find BTF for extern 'bpf_kfunc_call_test1' [27] section: -2
Error: failed to open BPF object file: No such file or directory
make: *** [Makefile:484: /local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/test_ksyms_module.skel.h] Error 255
make: *** Deleting file '/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/test_ksyms_module.skel.h'
make: *** Waiting for unfinished jobs....
make: *** [Makefile:484: /local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/kfunc_call_test_subprog.skel.h] Error 255
make: *** Deleting file '/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/kfunc_call_test_subprog.skel.h'
make: *** [Makefile:482: /local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/linked_funcs.skel.h] Error 254
libbpf: failed to find BTF info for global/extern symbol 'input_rodata_weak'
Error: failed to link '/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/linked_vars1.o': Unknown error -2 (-2)
make: *** [Makefile:482: /local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/linked_vars.skel.h] Error 254
libbpf: failed to find BTF for extern 'tcp_cong_avoid_ai' [27] section: -2
Error: failed to open BPF object file: No such file or directory
make: *** [Makefile:486: /local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/bpf_cubic.skel.h] Error 255
make: *** Deleting file '/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/bpf_cubic.skel.h'
libbpf: failed to find BTF for extern 'bpf_kfunc_call_test1' [28] section: -2
Error: failed to open BPF object file: No such file or directory
make: *** [Makefile:486: /local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/kfunc_call_test.lskel.h] Error 255
make: *** Deleting file '/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/kfunc_call_test.lskel.h'
libbpf: failed to find BTF for extern 'tcp_reno_cong_avoid' [38] section: -2
Error: failed to open BPF object file: No such file or directory
libbpf: failed to find BTF for extern 'bpf_testmod_invalid_mod_kfunc' [18] section: -2
Error: failed to open BPF object file: No such file or directory
make: *** [Makefile:486: /local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/bpf_dctcp.skel.h] Error 255
make: *** Deleting file '/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/bpf_dctcp.skel.h'
make: *** [Makefile:486: /local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/test_ksyms_module.lskel.h] Error 255
make: *** Deleting file '/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/test_ksyms_module.lskel.h'

Re: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

From: Martin KaFai Lau <hidden>
Date: 2021-12-29 21:05:59

On Wed, Dec 29, 2021 at 06:29:05PM +0000, Tyler Wear wrote:

Unable to run any bpf tests do to errors below. These occur with and without the new patch. Is this a known issue?
Is the new test case required since bpf_skb_store_bytes() is already a tested function for other prog types?

libbpf: failed to find BTF for extern 'bpf_testmod_invalid_mod_kfunc' [18] section: -2
Error: failed to open BPF object file: No such file or directory
libbpf: failed to find BTF info for global/extern symbol 'my_tid'
Error: failed to link '/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/linked_funcs1.o': Unknown error -2 (-2)
libbpf: failed to find BTF for extern 'bpf_kfunc_call_test1' [27] section: -2

tools/testing/selftests/bpf/README.rst has details on these.

Ensure the llvm and pahole are up to date.
Also take a look at the "Testing patches" and "LLVM" section
in Documentation/bpf/bpf_devel_QA.rst.

RE: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

From: Tyler Wear (QUIC) <hidden>
Date: 2022-01-05 00:27:45

-----Original Message-----
From: Martin KaFai Lau <redacted>
Sent: Wednesday, December 29, 2021 1:06 PM
To: Tyler Wear <redacted>
Cc: Yonghong Song <redacted>; Tyler Wear (QUIC) <redacted>; netdev@vger.kernel.org; bpf@vger.kernel.org;
maze@google.com
Subject: Re: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.

On Wed, Dec 29, 2021 at 06:29:05PM +0000, Tyler Wear wrote:

quoted

Unable to run any bpf tests do to errors below. These occur with and without the new patch. Is this a known issue?
Is the new test case required since bpf_skb_store_bytes() is already a tested function for other prog types?

libbpf: failed to find BTF for extern 'bpf_testmod_invalid_mod_kfunc'
[18] section: -2
Error: failed to open BPF object file: No such file or directory
libbpf: failed to find BTF info for global/extern symbol 'my_tid'
Error: failed to link
'/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/linked_
funcs1.o': Unknown error -2 (-2)
libbpf: failed to find BTF for extern 'bpf_kfunc_call_test1' [27]
section: -2

tools/testing/selftests/bpf/README.rst has details on these.

Ensure the llvm and pahole are up to date.
Also take a look at the "Testing patches" and "LLVM" section in Documentation/bpf/bpf_devel_QA.rst.

This will also require adding the l3/l4_ csum_replace() api's then. Adding the csum_replace() to a cgroup test case results in the below error during bpf program validation:
"BPF_LD_[ABS|IND] instructions not allowed for this program type"

Is there something else that needs to be added? Or would it be better to create the function just for ds_field?

Re: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

From: Yonghong Song <hidden>
Date: 2022-01-06 07:51:10


On 1/4/22 4:27 PM, Tyler Wear (QUIC) wrote:

quoted

-----Original Message-----
From: Martin KaFai Lau <redacted>
Sent: Wednesday, December 29, 2021 1:06 PM
To: Tyler Wear <redacted>
Cc: Yonghong Song <redacted>; Tyler Wear (QUIC) <redacted>; netdev@vger.kernel.org; bpf@vger.kernel.org;
maze@google.com
Subject: Re: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.

On Wed, Dec 29, 2021 at 06:29:05PM +0000, Tyler Wear wrote:

quoted

Unable to run any bpf tests do to errors below. These occur with and without the new patch. Is this a known issue?
Is the new test case required since bpf_skb_store_bytes() is already a tested function for other prog types?

libbpf: failed to find BTF for extern 'bpf_testmod_invalid_mod_kfunc'
[18] section: -2
Error: failed to open BPF object file: No such file or directory
libbpf: failed to find BTF info for global/extern symbol 'my_tid'
Error: failed to link
'/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/linked_
funcs1.o': Unknown error -2 (-2)
libbpf: failed to find BTF for extern 'bpf_kfunc_call_test1' [27]
section: -2

tools/testing/selftests/bpf/README.rst has details on these.

Ensure the llvm and pahole are up to date.
Also take a look at the "Testing patches" and "LLVM" section in Documentation/bpf/bpf_devel_QA.rst.

This will also require adding the l3/l4_ csum_replace() api's then. Adding the csum_replace() to a cgroup test case results in the below error during bpf program validation:
"BPF_LD_[ABS|IND] instructions not allowed for this program type"

I saw you posted a new patch, so it seems you have resolved this BPF_LD_[ABS|IND] issue. Do you know what is the reason for this verification error? Here, the program type is cgroup_skb which should not mess up with BPF_LD_[ABS|IND] which is mostly for classic bpf to extended bpf conversion. Did I miss anything here?

Is there something else that needs to be added? Or would it be better to create the function just for ds_field?

RE: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

From: Tyler Wear (QUIC) <hidden>
Date: 2022-01-06 17:18:57

-----Original Message-----
From: Yonghong Song <redacted>
Sent: Wednesday, January 5, 2022 11:51 PM
To: Tyler Wear (QUIC) <redacted>; Martin KaFai Lau <redacted>
Cc: netdev@vger.kernel.org; bpf@vger.kernel.org; maze@google.com
Subject: Re: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.

On 1/4/22 4:27 PM, Tyler Wear (QUIC) wrote:

quoted

-----Original Message-----
From: Martin KaFai Lau <redacted>
Sent: Wednesday, December 29, 2021 1:06 PM
To: Tyler Wear <redacted>
Cc: Yonghong Song <redacted>; Tyler Wear (QUIC)
[off-list ref]; netdev@vger.kernel.org;
bpf@vger.kernel.org; maze@google.com
Subject: Re: [PATCH] Add skb_store_bytes() for
BPF_PROG_TYPE_CGROUP_SKB

WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable

macros.

quoted

On Wed, Dec 29, 2021 at 06:29:05PM +0000, Tyler Wear wrote:

quoted

Unable to run any bpf tests do to errors below. These occur with and without the new patch. Is this a known issue?
Is the new test case required since bpf_skb_store_bytes() is already a tested function for other prog types?

libbpf: failed to find BTF for extern 'bpf_testmod_invalid_mod_kfunc'
[18] section: -2
Error: failed to open BPF object file: No such file or directory
libbpf: failed to find BTF info for global/extern symbol 'my_tid'
Error: failed to link
'/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/linke
d_
funcs1.o': Unknown error -2 (-2)
libbpf: failed to find BTF for extern 'bpf_kfunc_call_test1' [27]
section: -2

tools/testing/selftests/bpf/README.rst has details on these.

Ensure the llvm and pahole are up to date.
Also take a look at the "Testing patches" and "LLVM" section in Documentation/bpf/bpf_devel_QA.rst.

This will also require adding the l3/l4_ csum_replace() api's then. Adding the csum_replace() to a cgroup test case results in the

below error during bpf program validation:

quoted

"BPF_LD_[ABS|IND] instructions not allowed for this program type"

I saw you posted a new patch, so it seems you have resolved this BPF_LD_[ABS|IND] issue. Do you know what is the reason for this
verification error? Here, the program type is cgroup_skb which should not mess up with BPF_LD_[ABS|IND] which is mostly for classic
bpf to extended bpf conversion. Did I miss anything here?

Was an issue with using bpf_legacy.h to load bytes.

Re: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

From: Yonghong Song <hidden>
Date: 2022-01-06 22:36:04


On 1/6/22 9:18 AM, Tyler Wear (QUIC) wrote:

quoted

-----Original Message-----
From: Yonghong Song <redacted>
Sent: Wednesday, January 5, 2022 11:51 PM
To: Tyler Wear (QUIC) <redacted>; Martin KaFai Lau <redacted>
Cc: netdev@vger.kernel.org; bpf@vger.kernel.org; maze@google.com
Subject: Re: [PATCH] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.

On 1/4/22 4:27 PM, Tyler Wear (QUIC) wrote:

quoted

-----Original Message-----
From: Martin KaFai Lau <redacted>
Sent: Wednesday, December 29, 2021 1:06 PM
To: Tyler Wear <redacted>
Cc: Yonghong Song <redacted>; Tyler Wear (QUIC)
[off-list ref]; netdev@vger.kernel.org;
bpf@vger.kernel.org; maze@google.com
Subject: Re: [PATCH] Add skb_store_bytes() for
BPF_PROG_TYPE_CGROUP_SKB

WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable

macros.

quoted

On Wed, Dec 29, 2021 at 06:29:05PM +0000, Tyler Wear wrote:

quoted

Unable to run any bpf tests do to errors below. These occur with and without the new patch. Is this a known issue?
Is the new test case required since bpf_skb_store_bytes() is already a tested function for other prog types?

libbpf: failed to find BTF for extern 'bpf_testmod_invalid_mod_kfunc'
[18] section: -2
Error: failed to open BPF object file: No such file or directory
libbpf: failed to find BTF info for global/extern symbol 'my_tid'
Error: failed to link
'/local/mnt/workspace/linux-stable/tools/testing/selftests/bpf/linke
d_
funcs1.o': Unknown error -2 (-2)
libbpf: failed to find BTF for extern 'bpf_kfunc_call_test1' [27]
section: -2

tools/testing/selftests/bpf/README.rst has details on these.

Ensure the llvm and pahole are up to date.
Also take a look at the "Testing patches" and "LLVM" section in Documentation/bpf/bpf_devel_QA.rst.

This will also require adding the l3/l4_ csum_replace() api's then. Adding the csum_replace() to a cgroup test case results in the

below error during bpf program validation:

quoted

"BPF_LD_[ABS|IND] instructions not allowed for this program type"

I saw you posted a new patch, so it seems you have resolved this BPF_LD_[ABS|IND] issue. Do you know what is the reason for this
verification error? Here, the program type is cgroup_skb which should not mess up with BPF_LD_[ABS|IND] which is mostly for classic
bpf to extended bpf conversion. Did I miss anything here?

Was an issue with using bpf_legacy.h to load bytes.

Okay, I see. that makes sense. The helper bpf_skb_load_bytes() is the way to go.

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