kernel/linux.git/samples/bpf, branch v6.1.87

work around gcc bugs with 'asm goto' with outputs

2024-02-23T08:12:28+00:00

commit 68fb3ca0e408e00db1c3f8fccdfa19e274c033be 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'. 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 Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/ Cc: Nick Desaulniers Cc: Uros Bizjak Cc: Jakub Jelinek Cc: Andrew Pinski Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

samples/bpf: fix broken map lookup probe

2023-09-13T07:42:34+00:00

[ Upstream commit d93a7cf6ca2cfcd7de5d06f753ce8d5e863316ac ] In the commit 7c4cd051add3 ("bpf: Fix syscall's stackmap lookup potential deadlock"), a potential deadlock issue was addressed, which resulted in *_map_lookup_elem not triggering BPF programs. (prior to lookup, bpf_disable_instrumentation() is used) To resolve the broken map lookup probe using "htab_map_lookup_elem", this commit introduces an alternative approach. Instead, it utilize "bpf_map_copy_value" and apply a filter specifically for the hash table with map_type. Signed-off-by: Daniel T. Lee Fixes: 7c4cd051add3 ("bpf: Fix syscall's stackmap lookup potential deadlock") Link: https://lore.kernel.org/r/20230818090119.477441-8-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

samples/bpf: fix bio latency check with tracepoint

2023-09-13T07:42:34+00:00

[ Upstream commit 92632115fb57ff9e368f256913e96d6fd5abf5ab ] Recently, a new tracepoint for the block layer, specifically the block_io_start/done tracepoints, was introduced in commit 5a80bd075f3b ("block: introduce block_io_start/block_io_done tracepoints"). Previously, the kprobe entry used for this purpose was quite unstable and inherently broke relevant probes [1]. Now that a stable tracepoint is available, this commit replaces the bio latency check with it. One of the changes made during this replacement is the key used for the hash table. Since 'struct request' cannot be used as a hash key, the approach taken follows that which was implemented in bcc/biolatency [2]. (uses dev:sector for the key) [1]: https://github.com/iovisor/bcc/issues/4261 [2]: https://github.com/iovisor/bcc/pull/4691 Fixes: 450b7879e345 ("block: move blk_account_io_{start,done} to blk-mq.c") Signed-off-by: Daniel T. Lee Link: https://lore.kernel.org/r/20230818090119.477441-7-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

samples/bpf: xdp1 and xdp2 reduce XDPBUFSIZE to 60

2023-07-19T14:21:07+00:00

[ Upstream commit 60548b825b082cedf89b275c21c28b1e1d030e50 ] Default samples/pktgen scripts send 60 byte packets as hardware adds 4-bytes FCS checksum, which fulfils minimum Ethernet 64 bytes frame size. XDP layer will not necessary have access to the 4-bytes FCS checksum. This leads to bpf_xdp_load_bytes() failing as it tries to copy 64-bytes from an XDP packet that only have 60-bytes available. Fixes: 772251742262 ("samples/bpf: fixup some tools to be able to support xdp multibuffer") Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann Reviewed-by: Tariq Toukan Link: https://lore.kernel.org/bpf/168545704139.2996228.2516528552939485216.stgit@firesoul Signed-off-by: Sasha Levin

samples/bpf: Fix buffer overflow in tcp_basertt

2023-07-19T14:21:04+00:00

[ Upstream commit f4dea9689c5fea3d07170c2cb0703e216f1a0922 ] Using sizeof(nv) or strlen(nv)+1 is correct. Fixes: c890063e4404 ("bpf: sample BPF_SOCKET_OPS_BASE_RTT program") Signed-off-by: Pengcheng Yang Link: https://lore.kernel.org/r/1683276658-2860-1-git-send-email-yangpc@wangsu.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

samples/bpf: Fix fout leak in hbm's run_bpf_prog

2023-05-24T16:32:38+00:00

[ Upstream commit 23acb14af1914010dd0aae1bbb7fab28bf518b8e ] Fix fout being fopen'ed but then not subsequently fclose'd. In the affected branch, fout is otherwise going out of scope. Signed-off-by: Hao Zeng Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20230411084349.1999628-1-zenghao@kylinos.cn Signed-off-by: Sasha Levin

samples/bpf: Fix MAC address swapping in xdp2_kern

2022-12-31T12:32:03+00:00

[ Upstream commit 7a698edf954cb3f8b6e8dacdb77615355170420c ] xdp2_kern rewrites and forwards packets out on the same interface. Forwarding still works but rewrite got broken when xdp multibuffer support has been added. With xdp multibuffer a local copy of the packet has been introduced. The MAC address is now swapped in the local copy, but the local copy in not written back. Fix MAC address swapping be adding write back of modified packet. Fixes: 772251742262 ("samples/bpf: fixup some tools to be able to support xdp multibuffer") Signed-off-by: Gerhard Engleder Reviewed-by: Andy Gospodarek Link: https://lore.kernel.org/r/20221015213050.65222-1-gerhard@engleder-embedded.com Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin

samples/bpf: Fix map iteration in xdp1_user

2022-12-31T12:32:03+00:00

[ Upstream commit 05ee658c654bacda03f7fecef367e62aaf8e1cfe ] BPF map iteration in xdp1_user results in endless loop without any output, because the return value of bpf_map_get_next_key() is checked against the wrong value. Other call locations of bpf_map_get_next_key() check for equal 0 for continuing the iteration. xdp1_user checks against unequal -1. This is wrong for a function which can return arbitrary negative errno values, because a return value of e.g. -2 results in an endless loop. With this fix xdp1_user is printing statistics again: proto 0: 1 pkt/s proto 0: 1 pkt/s proto 17: 107383 pkt/s proto 17: 881655 pkt/s proto 17: 882083 pkt/s proto 17: 881758 pkt/s Fixes: bd054102a8c7 ("libbpf: enforce strict libbpf 1.0 behaviors") Signed-off-by: Gerhard Engleder Acked-by: Song Liu Link: https://lore.kernel.org/r/20221013200922.17167-1-gerhard@engleder-embedded.com Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin

samples/bpf: Fix typo in xdp_router_ipv4 sample

2022-09-30T22:04:23+00:00

Fix typo in xdp_router_ipv4 sample. Signed-off-by: Deming Wang Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220927192527.8722-1-wangdeming@inspur.com

samples/bpf: Replace blk_account_io_done() with __blk_account_io_done()

2022-09-21T00:25:59+00:00

Since commit be6bfe36db17 ("block: inline hot paths of blk_account_io_*()") blk_account_io_*() become inline functions. Signed-off-by: Rong Tao Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/tencent_1CC476835C219FACD84B6715F0D785517E07@qq.com