diff options
| author | Daniel T. Lee <danieltimlee@gmail.com> | 2023-08-18 18:01:15 +0900 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-08-21 15:39:09 -0700 |
| commit | 11430421b440427e10dfb4bd2bdc418fab0ff166 (patch) | |
| tree | f156649f07571863b44b63965dc80f318ef4cff5 /samples/bpf/tracex1.bpf.c | |
| parent | 02dabc247ad68b41758bf39f11e2d682b8b32dd7 (diff) | |
samples/bpf: make tracing programs to be more CO-RE centric
The existing tracing programs have been developed for a considerable
period of time and, as a result, do not properly incorporate the
features of the current libbpf, such as CO-RE. This is evident in
frequent usage of functions like PT_REGS* and the persistence of "hack"
methods using underscore-style bpf_probe_read_kernel from the past.
These programs are far behind the current level of libbpf and can
potentially confuse users. Therefore, this commit aims to convert the
outdated BPF programs to be more CO-RE centric.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-6-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'samples/bpf/tracex1.bpf.c')
| -rw-r--r-- | samples/bpf/tracex1.bpf.c | 17 |
1 files changed, 5 insertions, 12 deletions
diff --git a/samples/bpf/tracex1.bpf.c b/samples/bpf/tracex1.bpf.c index f3be14a03964..0ab39d76ff8f 100644 --- a/samples/bpf/tracex1.bpf.c +++ b/samples/bpf/tracex1.bpf.c @@ -8,15 +8,9 @@ #include "net_shared.h" #include <linux/version.h> #include <bpf/bpf_helpers.h> +#include <bpf/bpf_core_read.h> #include <bpf/bpf_tracing.h> -#define _(P) \ - ({ \ - typeof(P) val = 0; \ - bpf_probe_read_kernel(&val, sizeof(val), &(P)); \ - val; \ - }) - /* kprobe is NOT a stable ABI * kernel functions can be removed, renamed or completely change semantics. * Number of arguments and their positions can change, etc. @@ -34,12 +28,11 @@ int bpf_prog1(struct pt_regs *ctx) struct sk_buff *skb; int len; - /* non-portable! works for the given kernel only */ - bpf_probe_read_kernel(&skb, sizeof(skb), (void *)PT_REGS_PARM1(ctx)); - dev = _(skb->dev); - len = _(skb->len); + bpf_core_read(&skb, sizeof(skb), (void *)PT_REGS_PARM1(ctx)); + dev = BPF_CORE_READ(skb, dev); + len = BPF_CORE_READ(skb, len); - bpf_probe_read_kernel(devname, sizeof(devname), dev->name); + BPF_CORE_READ_STR_INTO(&devname, dev, name); if (devname[0] == 'l' && devname[1] == 'o') { char fmt[] = "skb %p len %d\n"; |