wireguard-linux/kernel/bpf/btf.c, branch jd/bump-compilers

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2024-09-13T03:22:44Z

Daniel Borkmann says: ==================== pull-request: bpf-next 2024-09-11 We've added 12 non-merge commits during the last 16 day(s) which contain a total of 20 files changed, 228 insertions(+), 30 deletions(-). There's a minor merge conflict in drivers/net/netkit.c: 00d066a4d4ed ("netdev_features: convert NETIF_F_LLTX to dev->lltx") d96608794889 ("netkit: Disable netpoll support") The main changes are: 1) Enable bpf_dynptr_from_skb for tp_btf such that this can be used to easily parse skbs in BPF programs attached to tracepoints, from Philo Lu. 2) Add a cond_resched() point in BPF's sock_hash_free() as there have been several syzbot soft lockup reports recently, from Eric Dumazet. 3) Fix xsk_buff_can_alloc() to account for queue_empty_descs which got noticed when zero copy ice driver started to use it, from Maciej Fijalkowski. 4) Move the xdp:xdp_cpumap_kthread tracepoint before cpumap pushes skbs up via netif_receive_skb_list() to better measure latencies, from Daniel Xu. 5) Follow-up to disable netpoll support from netkit, from Daniel Borkmann. 6) Improve xsk selftests to not assume a fixed MAX_SKB_FRAGS of 17 but instead gather the actual value via /proc/sys/net/core/max_skb_frags, also from Maciej Fijalkowski. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: sock_map: Add a cond_resched() in sock_hash_free() selftests/bpf: Expand skb dynptr selftests for tp_btf bpf: Allow bpf_dynptr_from_skb() for tp_btf tcp: Use skb__nullable in trace_tcp_send_reset selftests/bpf: Add test for __nullable suffix in tp_btf bpf: Support __nullable argument suffix for tp_btf bpf, cpumap: Move xdp:xdp_cpumap_kthread tracepoint before rcv selftests/xsk: Read current MAX_SKB_FRAGS from sysctl knob xsk: Bump xsk_queue::queue_empty_descs in xp_can_alloc() tcp_bpf: Remove an unused parameter for bpf_tcp_ingress() bpf, sockmap: Correct spelling skmsg.c netkit: Disable netpoll support Signed-off-by: Jakub Kicinski ==================== Link: https://patch.msgid.link/20240911211525.13834-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski

bpf: Support __nullable argument suffix for tp_btf

2024-09-11T15:56:37Z

Pointers passed to tp_btf were trusted to be valid, but some tracepoints do take NULL pointer as input, such as trace_tcp_send_reset(). Then the invalid memory access cannot be detected by verifier. This patch fix it by add a suffix "__nullable" to the unreliable argument. The suffix is shown in btf, and PTR_MAYBE_NULL will be added to nullable arguments. Then users must check the pointer before use it. A problem here is that we use "btf_trace_##call" to search func_proto. As it is a typedef, argument names as well as the suffix are not recorded. To solve this, I use bpf_raw_event_map to find "__bpf_trace##template" from "btf_trace_##call", and then we can see the suffix. Suggested-by: Alexei Starovoitov Signed-off-by: Philo Lu Link: https://lore.kernel.org/r/20240911033719.91468-2-lulie@linux.alibaba.com Signed-off-by: Martin KaFai Lau

bpf: add check for invalid name in btf_name_valid_section()

2024-09-04T18:56:34Z

If the length of the name string is 1 and the value of name[0] is NULL byte, an OOB vulnerability occurs in btf_name_valid_section() and the return value is true, so the invalid name passes the check. To solve this, you need to check if the first position is NULL byte and if the first character is printable. Suggested-by: Eduard Zingerman Fixes: bd70a8fb7ca4 ("bpf: Allow all printable characters in BTF DATASEC names") Signed-off-by: Jeongjun Park Link: https://lore.kernel.org/r/20240831054702.364455-1-aha310510@gmail.com Signed-off-by: Alexei Starovoitov Acked-by: Eduard Zingerman

bpf: Fix a crash when btf_parse_base() returns an error pointer

2024-08-30T17:34:47Z

The pointer returned by btf_parse_base could be an error pointer. IS_ERR() check is needed before calling btf_free(base_btf). Fixes: 8646db238997 ("libbpf,bpf: Share BTF relocate-related code with kernel") Signed-off-by: Martin KaFai Lau Signed-off-by: Andrii Nakryiko Reviewed-by: Alan Maguire Acked-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20240830012214.1646005-1-martin.lau@linux.dev

bpf: Eliminate remaining "make W=1" warnings in kernel/bpf/btf.o

2024-07-12T15:02:26Z

As reported by Mirsad [1] we still see format warnings in kernel/bpf/btf.o at W=1 warning level: CC kernel/bpf/btf.o ./kernel/bpf/btf.c: In function ‘btf_type_seq_show_flags’: ./kernel/bpf/btf.c:7553:21: warning: assignment left-hand side might be a candidate for a format attribute [-Wsuggest-attribute=format] 7553 | sseq.showfn = btf_seq_show; | ^ ./kernel/bpf/btf.c: In function ‘btf_type_snprintf_show’: ./kernel/bpf/btf.c:7604:31: warning: assignment left-hand side might be a candidate for a format attribute [-Wsuggest-attribute=format] 7604 | ssnprintf.show.showfn = btf_snprintf_show; | ^ Combined with CONFIG_WERROR=y these can halt the build. The fix (annotating the structure field with __printf()) suggested by Mirsad resolves these. Apologies I missed this last time. No other W=1 warnings were observed in kernel/bpf after this fix. [1] https://lore.kernel.org/bpf/92c9d047-f058-400c-9c7d-81d4dc1ef71b@gmail.com/ Fixes: b3470da314fd ("bpf: annotate BTF show functions with __printf") Reported-by: Mirsad Todorovac Suggested-by: Mirsad Todorovac Signed-off-by: Alan Maguire Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20240712092859.1390960-1-alan.maguire@oracle.com

bpf: annotate BTF show functions with __printf

2024-07-11T21:15:17Z

-Werror=suggest-attribute=format warns about two functions in kernel/bpf/btf.c [1]; add __printf() annotations to silence these warnings since for CONFIG_WERROR=y they will trigger build failures. [1] https://lore.kernel.org/bpf/a8b20c72-6631-4404-9e1f-0410642d7d20@gmail.com/ Fixes: 31d0bc81637d ("bpf: Move to generic BTF show support, apply it to seq files/strings") Reported-by: Mirsad Todorovac Signed-off-by: Alan Maguire Tested-by: Mirsad Todorovac Link: https://lore.kernel.org/r/20240711182321.963667-1-alan.maguire@oracle.com Signed-off-by: Alexei Starovoitov

bpf: fix build when CONFIG_DEBUG_INFO_BTF[_MODULES] is undefined

2024-06-23T19:50:02Z

Kernel test robot reports that kernel build fails with resilient split BTF changes. Examining the associated config and code we see that btf_relocate_id() is defined under CONFIG_DEBUG_INFO_BTF_MODULES. Moving it outside the #ifdef solves the issue. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202406221742.d2srFLVI-lkp@intel.com/ Signed-off-by: Alan Maguire Link: https://lore.kernel.org/r/20240623135224.27981-1-alan.maguire@oracle.com Signed-off-by: Alexei Starovoitov

libbpf,bpf: Share BTF relocate-related code with kernel

2024-06-21T21:45:07Z

Share relocation implementation with the kernel. As part of this, we also need the type/string iteration functions so also share btf_iter.c file. Relocation code in kernel and userspace is identical save for the impementation of the reparenting of split BTF to the relocated base BTF and retrieval of the BTF header from "struct btf"; these small functions need separate user-space and kernel implementations for the separate "struct btf"s they operate upon. One other wrinkle on the kernel side is we have to map .BTF.ids in modules as they were generated with the type ids used at BTF encoding time. btf_relocate() optionally returns an array mapping from old BTF ids to relocated ids, so we use that to fix up these references where needed for kfuncs. Signed-off-by: Alan Maguire Signed-off-by: Andrii Nakryiko Acked-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20240620091733.1967885-5-alan.maguire@oracle.com

bpf: verifier: Relax caller requirements for kfunc projection type args

2024-06-12T18:01:31Z

Currently, if a kfunc accepts a projection type as an argument (eg struct __sk_buff *), the caller must exactly provide exactly the same type with provable provenance. However in practice, kfuncs that accept projection types _must_ cast to the underlying type before use b/c projection type layouts are completely made up. Thus, it is ok to relax the verifier rules around implicit conversions. We will use this functionality in the next commit when we align kfuncs to user-facing types. Signed-off-by: Daniel Xu Link: https://lore.kernel.org/r/e2c025cb09ccfd4af1ec9e18284dc3cecff7514d.1718207789.git.dxu@dxuuu.xyz Signed-off-by: Alexei Starovoitov

bpf: limit the number of levels of a nested struct type.

2024-06-04T03:52:42Z

Limit the number of levels looking into struct types to avoid running out of stack space. Acked-by: Eduard Zingerman Signed-off-by: Kui-Feng Lee Link: https://lore.kernel.org/r/20240523174202.461236-7-thinker.li@gmail.com Signed-off-by: Alexei Starovoitov