kernel.git/tools/net/bpf_dbg.c, branch linux-4.14.y

bpf: fix uninitialized variable in bpf tools

2018-06-20T19:02:49Z

[ Upstream commit 815425567dea6c54494e85050631d6bdda907c5d ] Here the variable cont is used as the saved_pointer for a call to strtok_r(). It is safe to use the value uninitialized in this context however and the later reference is only ever used if the strtok_r is successful. But, 'gcc-5' at least doesn't have all this knowledge so initialize cont to NULL. Additionally, do the natural NULL check before accessing just for completness. The warning is the following: ./bpf/tools/bpf/bpf_dbg.c: In function ‘cmd_load’: ./bpf/tools/bpf/bpf_dbg.c:1077:13: warning: ‘cont’ may be used uninitialized in this function [-Wmaybe-uninitialized] } else if (matches(subcmd, "pcap") == 0) { Fixes: fd981e3c321a "filter: bpf_dbg: add minimal bpf debugger" Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

bpf_dbg: do not initialise statics to 0

2016-02-11T09:24:45Z

This patch fixes the checkpatch.pl error to bpf_dbg.c: ERROR: do not initialise statics to 0 Signed-off-by: Wei Tang Signed-off-by: David S. Miller

bpf_dbg: fix wrong register usage

2014-04-30T20:12:22Z

The AND instruction is erroneously using the X register instead of the K register. Signed-off-by: Brendan Hickey Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

tools: bpf_dbg: various misc code cleanups

2014-02-25T00:02:10Z

Lets clean up bpf_dbg a bit and improve its code slightly in various areas: i) Get rid of some macros as there's no good reason for keeping them, ii) remove one unused variable and reduce scope of various variables found by cppcheck, iii) Close non-default file descriptors when exiting the shell. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

bpf_dbg: always close socket in bpf_runnable

2013-12-17T22:11:00Z

We must not leave the socket intact in bpf_runnable(). The socket is used to test if the filter code is being accepted by the kernel or not. So right after we do the setsockopt(2), we need to close it again. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

filter: bpf_dbg: add minimal bpf debugger

2013-12-12T01:28:35Z

This patch adds a minimal BPF debugger that "emulates" the kernel's BPF engine (w/o extensions) and allows for single stepping (forwards and backwards through BPF code) or running with >=1 breakpoints through selected or all packets from a pcap file with a provided user filter in order to facilitate verification of a BPF program. When a breakpoint is being hit, it dumps all register contents, decoded instructions and in case of branches both decoded branch targets as well as other useful information. Having this facility is in particular useful to verify BPF programs against given test traffic *before* attaching to a live system. With the general availability of cls_bpf, xt_bpf, socket filters, team driver and e.g. PTP code, all BPF users, quite often a single more complex BPF program is being used. Reasons for a more complex BPF program are primarily to optimize execution time for making a verdict when multiple simple BPF programs are combined into one in order to prevent parsing same headers multiple times. In particular, for cls_bpf that can have various return paths for encoding flowids, and xt_bpf to come to a fw verdict this can be the case. Therefore, as this can result in more complex and harder to debug code, it would be very useful to have this minimal tool for testing purposes. It can also be of help for BPF JIT developers as filters are "test attached" to the kernel on a temporary socket thus triggering a JIT image dump when enabled. The tool uses an interactive libreadline shell with auto-completion and history support. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller