kernel/samples/bpf/bpf_load.c, branch linux-5.1.y

samples, bpf: fix to change the buffer size for read()

2019-07-14T06:09:35Z

[ Upstream commit f7c2d64bac1be2ff32f8e4f500c6e5429c1003e0 ] If the trace for read is larger than 4096, the return value sz will be 4096. This results in off-by-one error on buf: static char buf[4096]; ssize_t sz; sz = read(trace_fd, buf, sizeof(buf)); if (sz > 0) { buf[sz] = 0; puts(buf); } Signed-off-by: Chang-Hsien Tsai Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin

samples: bpf: fix: seg fault with NULL pointer arg

2018-12-03T22:58:03Z

When NULL pointer accidentally passed to write_kprobe_events, due to strlen(NULL), segmentation fault happens. Changed code returns -1 to deal with this situation. Bug issued with Smatch, static analysis. Signed-off-by: Daniel T. Lee Acked-by: Song Liu Signed-off-by: Daniel Borkmann

samples: bpf: fix: error handling regarding kprobe_events

2018-11-23T21:39:09Z

Currently, kprobe_events failure won't be handled properly. Due to calling system() indirectly to write to kprobe_events, it can't be identified whether an error is derived from kprobe or system. // buf = "echo '%c:%s %s' >> /s/k/d/t/kprobe_events" err = system(buf); if (err < 0) { printf("failed to create kprobe .."); return -1; } For example, running ./tracex7 sample in ext4 partition, "echo p:open_ctree open_ctree >> /s/k/d/t/kprobe_events" gets 256 error code system() failure. => The error comes from kprobe, but it's not handled correctly. According to man of system(3), it's return value just passes the termination status of the child shell rather than treating the error as -1. (don't care success) Which means, currently it's not working as desired. (According to the upper code snippet) ex) running ./tracex7 with ext4 env. # Current Output sh: echo: I/O error failed to open event open_ctree # Desired Output failed to create kprobe 'open_ctree' error 'No such file or directory' The problem is, error can't be verified whether from child ps or system. But using write() directly can verify the command failure, and it will treat all error as -1. So I suggest using write() directly to 'kprobe_events' rather than calling system(). Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann

bpf_load: add map name to load_maps error message

2018-11-07T21:34:54Z

To help when debugging bpf/xdp load issues, have the load_map() error message include the number and name of the map that failed. Signed-off-by: Shannon Nelson Acked-by: John Fastabend Acked-by: Song Liu Signed-off-by: Daniel Borkmann

samples/bpf: remove duplicated includes

2018-09-18T15:49:33Z

Remove duplicated includes. Signed-off-by: YueHaibing Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann

samples: bpf: ensure that we don't load over MAX_PROGS programs

2018-07-16T22:00:56Z

I can't see that we check prog_cnt to ensure it doesn't go over MAX_PROGS. Signed-off-by: Dan Carpenter Signed-off-by: Alexei Starovoitov

samples: bpf: include bpf/bpf.h instead of local libbpf.h

2018-05-15T05:52:10Z

There are two files in the tree called libbpf.h which is becoming problematic. Most samples don't actually need the local libbpf.h they simply include it to get to bpf/bpf.h. Include bpf/bpf.h directly instead. Signed-off-by: Jakub Kicinski Acked-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov

samples: bpf: rename struct bpf_map_def to avoid conflict with libbpf

2018-05-10T23:40:51Z

Both tools/lib/bpf/libbpf.h and samples/bpf/bpf_load.h define their own version of struct bpf_map_def. The version in bpf_load.h has more fields. libbpf does not support inner maps and its definition of struct bpf_map_def lacks the related fields. Rename the definition in bpf_load.h (samples/bpf) to avoid conflicts. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann

samples/bpf: fix kprobe attachment issue on x64

2018-04-30T03:36:53Z

Commit d5a00528b58c ("syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()") renamed a lot of syscall function sys_*() to __x64_sys_*(). This caused several kprobe based samples/bpf tests failing. This patch fixed the problem in bpf_load.c. For x86_64 architecture, function name __x64_sys_*() will be first used for kprobe event creation. If the creation is successful, it will be used. Otherwise, function name sys_*() will be used for kprobe event creation. Fixes: d5a00528b58c ("syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()") Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov

samples/bpf: move common-purpose trace functions to selftests

2018-04-29T15:45:54Z

There is no functionality change in this patch. The common-purpose trace functions, including perf_event polling and ksym lookup, are moved from trace_output_user.c and bpf_load.c to selftests/bpf/trace_helpers.c so that these function can be reused later in selftests. Acked-by: Alexei Starovoitov Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov