- 17 4月, 2015 1 次提交
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由 Alexei Starovoitov 提交于
1. first bug is a silly mistake. It broke tracing examples and prevented simple bpf programs from loading. In the following code: if (insn->imm == 0 && BPF_SIZE(insn->code) == BPF_W) { } else if (...) { // this part should have been executed when // insn->code == BPF_W and insn->imm != 0 } Obviously it's not doing that. So simple instructions like: r2 = *(u64 *)(r1 + 8) will be rejected. Note the comments in the code around these branches were and still valid and indicate the true intent. Replace it with: if (BPF_SIZE(insn->code) != BPF_W) continue; if (insn->imm == 0) { } else if (...) { // now this code will be executed when // insn->code == BPF_W and insn->imm != 0 } 2. second bug is more subtle. If malicious code is using the same dest register as source register, the checks designed to prevent the same instruction to be used with different pointer types will fail to trigger, since we were assigning src_reg_type when it was already overwritten by check_mem_access(). The fix is trivial. Just move line: src_reg_type = regs[insn->src_reg].type; before check_mem_access(). Add new 'access skb fields bad4' test to check this case. Fixes: 9bac3d6d ("bpf: allow extended BPF programs access skb fields") Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 02 4月, 2015 1 次提交
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由 Alexei Starovoitov 提交于
tracex1_kern.c - C program compiled into BPF. It attaches to kprobe:netif_receive_skb() When skb->dev->name == "lo", it prints sample debug message into trace_pipe via bpf_trace_printk() helper function. tracex1_user.c - corresponding user space component that: - loads BPF program via bpf() syscall - opens kprobes:netif_receive_skb event via perf_event_open() syscall - attaches the program to event via ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); - prints from trace_pipe Note, this BPF program is non-portable. It must be recompiled with current kernel headers. kprobe is not a stable ABI and BPF+kprobe scripts may no longer be meaningful when kernel internals change. No matter in what way the kernel changes, neither the kprobe, nor the BPF program can ever crash or corrupt the kernel, assuming the kprobes, perf and BPF subsystem has no bugs. The verifier will detect that the program is using bpf_trace_printk() and the kernel will print 'this is a DEBUG kernel' warning banner, which means that bpf_trace_printk() should be used for debugging of the BPF program only. Usage: $ sudo tracex1 ping-19826 [000] d.s2 63103.382648: : skb ffff880466b1ca00 len 84 ping-19826 [000] d.s2 63103.382684: : skb ffff880466b1d300 len 84 ping-19826 [000] d.s2 63104.382533: : skb ffff880466b1ca00 len 84 ping-19826 [000] d.s2 63104.382594: : skb ffff880466b1d300 len 84 Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1427312966-8434-7-git-send-email-ast@plumgrid.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 18 3月, 2015 1 次提交
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由 Alexei Starovoitov 提交于
as a follow on to patch 70006af9 ("bpf: allow eBPF access skb fields") this patch allows 'protocol' and 'vlan_tci' fields to be accessible from extended BPF programs. The usage of 'protocol', 'vlan_present' and 'vlan_tci' fields is the same as corresponding SKF_AD_PROTOCOL, SKF_AD_VLAN_TAG_PRESENT and SKF_AD_VLAN_TAG accesses in classic BPF. Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 16 3月, 2015 1 次提交
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由 Alexei Starovoitov 提交于
- modify sockex1 example to count number of bytes in outgoing packets - modify sockex2 example to count number of bytes and packets per flow - add 4 stress tests that exercise 'skb->field' code path of verifier Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 02 3月, 2015 1 次提交
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由 Daniel Borkmann 提交于
Now that we have BPF_PROG_TYPE_SOCKET_FILTER up and running, we can remove the test stubs which were added to get the verifier suite up. We can just let the test cases probe under socket filter type instead. In the fill/spill test case, we cannot (yet) access fields from the context (skb), but we may adapt that test case in future. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@plumgrid.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 19 11月, 2014 1 次提交
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由 Alexei Starovoitov 提交于
proper types and function helpers are ready. Use them in verifier testsuite. Remove temporary stubs Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 31 10月, 2014 1 次提交
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由 Alexei Starovoitov 提交于
- add a test specifically targeting verifier state pruning. It checks state propagation between registers, storing that state into stack and state pruning algorithm recognizing equivalent stack and register states. - add summary line to spot failures easier Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 22 10月, 2014 1 次提交
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由 Alexei Starovoitov 提交于
while comparing for verifier state equivalency the comparison was missing a check for uninitialized register. Make sure it does so and add a testcase. Fixes: f1bca824 ("bpf: add search pruning optimization to verifier") Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com> Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 02 10月, 2014 1 次提交
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由 Alexei Starovoitov 提交于
add 4 extra tests to cover jump verification better Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 27 9月, 2014 1 次提交
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由 Alexei Starovoitov 提交于
1. the library includes a trivial set of BPF syscall wrappers: int bpf_create_map(int key_size, int value_size, int max_entries); int bpf_update_elem(int fd, void *key, void *value); int bpf_lookup_elem(int fd, void *key, void *value); int bpf_delete_elem(int fd, void *key); int bpf_get_next_key(int fd, void *key, void *next_key); int bpf_prog_load(enum bpf_prog_type prog_type, const struct sock_filter_int *insns, int insn_len, const char *license); bpf_prog_load() stores verifier log into global bpf_log_buf[] array and BPF_*() macros to build instructions 2. test stubs configure eBPF infra with 'unspec' map and program types. These are fake types used by user space testsuite only. 3. verifier tests valid and invalid programs and expects predefined error log messages from kernel. 40 tests so far. $ sudo ./test_verifier #0 add+sub+mul OK #1 unreachable OK #2 unreachable2 OK #3 out of range jump OK #4 out of range jump2 OK #5 test1 ld_imm64 OK ... Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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