kernel/samples/bpf, branch linux-5.7.y

samples: bpf: Fix bpf programs with kprobe/sys_connect event

2020-08-19T06:23:52Z

[ Upstream commit af9bd3e3331b8af42b6606c75797d041ab39380c ] Currently, BPF programs with kprobe/sys_connect does not work properly. Commit 34745aed515c ("samples/bpf: fix kprobe attachment issue on x64") This commit modifies the bpf_load behavior of kprobe events in the x64 architecture. If the current kprobe event target starts with "sys_*", add the prefix "__x64_" to the front of the event. Appending "__x64_" prefix with kprobe/sys_* event was appropriate as a solution to most of the problems caused by the commit below. commit d5a00528b58c ("syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()") However, there is a problem with the sys_connect kprobe event that does not work properly. For __sys_connect event, parameters can be fetched normally, but for __x64_sys_connect, parameters cannot be fetched. ffffffff818d3520 <__x64_sys_connect>: ffffffff818d3520: e8 fb df 32 00 callq 0xffffffff81c01520 <__fentry__> ffffffff818d3525: 48 8b 57 60 movq 96(%rdi), %rdx ffffffff818d3529: 48 8b 77 68 movq 104(%rdi), %rsi ffffffff818d352d: 48 8b 7f 70 movq 112(%rdi), %rdi ffffffff818d3531: e8 1a ff ff ff callq 0xffffffff818d3450 <__sys_connect> ffffffff818d3536: 48 98 cltq ffffffff818d3538: c3 retq ffffffff818d3539: 0f 1f 80 00 00 00 00 nopl (%rax) As the assembly code for __x64_sys_connect shows, parameters should be fetched and set into rdi, rsi, rdx registers prior to calling __sys_connect. Because of this problem, this commit fixes the sys_connect event by first getting the value of the rdi register and then the value of the rdi, rsi, and rdx register through an offset based on that value. Fixes: 34745aed515c ("samples/bpf: fix kprobe attachment issue on x64") Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200707184855.30968-2-danieltimlee@gmail.com Signed-off-by: Sasha Levin

bpf: Fix fds_example SIGSEGV error

2020-08-19T06:23:39Z

[ Upstream commit eef8a42d6ce087d1c81c960ae0d14f955b742feb ] The `BPF_LOG_BUF_SIZE`'s value is `UINT32_MAX >> 8`, so define an array with it on stack caused an overflow. Signed-off-by: Wenbo Zhang Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200710092035.28919-1-ethercflow@gmail.com Signed-off-by: Sasha Levin

bpf, xdp, samples: Fix null pointer dereference in *_user code

2020-06-30T19:36:03Z

[ Upstream commit 6903cdae9f9f08d61e49c16cbef11c293e33a615 ] Memset on the pointer right after malloc can cause a NULL pointer deference if it failed to allocate memory. A simple fix is to replace malloc()/memset() pair with a simple call to calloc(). Fixes: 0fca931a6f21 ("samples/bpf: program demonstrating access to xdp_rxq_info") Signed-off-by: Gaurav Singh Signed-off-by: Daniel Borkmann Acked-by: Jesper Dangaard Brouer Acked-by: John Fastabend Signed-off-by: Sasha Levin

samples/bpf: xdp_redirect_cpu: Set MAX_CPUS according to NR_CPUS

2020-06-30T19:36:03Z

[ Upstream commit 6a09815428547657f3ffd2f5c31ac2a191e7fdf3 ] xdp_redirect_cpu is currently failing in bpf_prog_load_xattr() allocating cpu_map map if CONFIG_NR_CPUS is less than 64 since cpu_map_alloc() requires max_entries to be less than NR_CPUS. Set cpu_map max_entries according to NR_CPUS in xdp_redirect_cpu_kern.c and get currently running cpus in xdp_redirect_cpu_user.c Signed-off-by: Lorenzo Bianconi Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/374472755001c260158c4e4b22f193bdd3c56fb7.1589300442.git.lorenzo@kernel.org Signed-off-by: Sasha Levin

samples: bpf: Fix build error

2020-05-14T19:37:39Z

GCC 10 is very strict about symbol clash, and lwt_len_hist_user contains a symbol which clashes with libbpf: /usr/bin/ld: samples/bpf/lwt_len_hist_user.o:(.bss+0x0): multiple definition of `bpf_log_buf'; samples/bpf/bpf_load.o:(.bss+0x8c0): first defined here collect2: error: ld returned 1 exit status bpf_log_buf here seems to be a leftover, so removing it. Signed-off-by: Matteo Croce Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200511113234.80722-1-mcroce@redhat.com

Merge tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx

2020-04-03T20:12:26Z

Pull SPDX updates from Greg KH: "Here are three SPDX patches for 5.7-rc1. One fixes up the SPDX tag for a single driver, while the other two go through the tree and add SPDX tags for all of the .gitignore files as needed. Nothing too complex, but you will get a merge conflict with your current tree, that should be trivial to handle (one file modified by two things, one file deleted.) All three of these have been in linux-next for a while, with no reported issues other than the merge conflict" * tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: ASoC: MT6660: make spdxcheck.py happy .gitignore: add SPDX License Identifier .gitignore: remove too obvious comments

.gitignore: add SPDX License Identifier

2020-03-25T10:50:48Z

Add SPDX License Identifier to all .gitignore files. Signed-off-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman

samples, bpf: Refactor perf_event user program with libbpf bpf_link

2020-03-23T21:27:57Z

The bpf_program__attach of libbpf(using bpf_link) is much more intuitive than the previous method using ioctl. bpf_program__attach_perf_event manages the enable of perf_event and attach of BPF programs to it, so there's no neeed to do this directly with ioctl. In addition, bpf_link provides consistency in the use of API because it allows disable (detach, destroy) for multiple events to be treated as one bpf_link__destroy. Also, bpf_link__destroy manages the close() of perf_event fd. This commit refactors samples that attach the bpf program to perf_event by using libbbpf instead of ioctl. Also the bpf_load in the samples were removed and migrated to use libbbpf API. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200321100424.1593964-3-danieltimlee@gmail.com

samples, bpf: Move read_trace_pipe to trace_helpers

2020-03-23T21:27:51Z

To reduce the reliance of trace samples (trace*_user) on bpf_load, move read_trace_pipe to trace_helpers. By moving this bpf_loader helper elsewhere, trace functions can be easily migrated to libbbpf. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200321100424.1593964-2-danieltimlee@gmail.com

Merge tag 'kbuild-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2020-02-10T00:05:50Z

Pull more Kbuild updates from Masahiro Yamada: - fix randconfig to generate a sane .config - rename hostprogs-y / always to hostprogs / always-y, which are more natual syntax. - optimize scripts/kallsyms - fix yes2modconfig and mod2yesconfig - make multiple directory targets ('make foo/ bar/') work * tag 'kbuild-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: make multiple directory targets work kconfig: Invalidate all symbols after changing to y or m. kallsyms: fix type of kallsyms_token_table[] scripts/kallsyms: change table to store (strcut sym_entry *) scripts/kallsyms: rename local variables in read_symbol() kbuild: rename hostprogs-y/always to hostprogs/always-y kbuild: fix the document to use extra-y for vmlinux.lds kconfig: fix broken dependency in randconfig-generated .config