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| author | Daniel T. Lee <danieltimlee@gmail.com> | 2023-08-18 12:01:15 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-08-22 01:39:09 +0300 |
| commit | 11430421b440427e10dfb4bd2bdc418fab0ff166 (patch) | |
| tree | f156649f07571863b44b63965dc80f318ef4cff5 /samples/bpf/offwaketime.bpf.c | |
| parent | 02dabc247ad68b41758bf39f11e2d682b8b32dd7 (diff) | |
| download | linux-11430421b440427e10dfb4bd2bdc418fab0ff166.tar.xz | |
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outdated BPF programs to be more CO-RE centric.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/offwaketime.bpf.c')
| -rw-r--r-- | samples/bpf/offwaketime.bpf.c | 18 |
1 files changed, 5 insertions, 13 deletions
diff --git a/samples/bpf/offwaketime.bpf.c b/samples/bpf/offwaketime.bpf.c index 3200a0f44969..4a65ba76c1b1 100644 --- a/samples/bpf/offwaketime.bpf.c +++ b/samples/bpf/offwaketime.bpf.c @@ -8,18 +8,12 @@ #include <linux/version.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> +#include <bpf/bpf_core_read.h> #ifndef PERF_MAX_STACK_DEPTH #define PERF_MAX_STACK_DEPTH 127 #endif -#define _(P) \ - ({ \ - typeof(P) val; \ - bpf_probe_read_kernel(&val, sizeof(val), &(P)); \ - val; \ - }) - #define MINBLOCK_US 1 #define MAX_ENTRIES 10000 @@ -68,11 +62,9 @@ struct { SEC("kprobe/try_to_wake_up") int waker(struct pt_regs *ctx) { - struct task_struct *p = (void *) PT_REGS_PARM1(ctx); + struct task_struct *p = (void *)PT_REGS_PARM1_CORE(ctx); + u32 pid = BPF_CORE_READ(p, pid); struct wokeby_t woke; - u32 pid; - - pid = _(p->pid); bpf_get_current_comm(&woke.name, sizeof(woke.name)); woke.ret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS); @@ -121,9 +113,9 @@ int oncpu(struct trace_event_raw_sched_switch *ctx) SEC("kprobe.multi/finish_task_switch*") int oncpu(struct pt_regs *ctx) { - struct task_struct *p = (void *) PT_REGS_PARM1(ctx); + struct task_struct *p = (void *)PT_REGS_PARM1_CORE(ctx); /* record previous thread sleep time */ - u32 pid = _(p->pid); + u32 pid = BPF_CORE_READ(p, pid); #endif u64 delta, ts, *tsp; |