bcc/libbpf-tools: Replace bpf_probe_read with bpf_probe_read_kernel.

As kernel commit b8ebce86ffe6 ("libbpf: Provide CO-RE variants of
PT_REGS macros") is introduced after bpf_probe_read_kernel changes, it
is safe to use bpf_probe_read_kernel directly

Signed-off-by: Sumanth Korikkar <[email protected]>
Acked-by: Ilya Leoshkevich <[email protected]>

libbpf-tools/drsnoop.bpf.c

@@ -42,7 +42,7 @@ int handle__mm_vmscan_direct_reclaim_begin(u64 *ctx)
 
  piddata.ts = bpf_ktime_get_ns();
  if (vm_zone_stat_kaddrp) {
- bpf_probe_read(&piddata.nr_free_pages,
+ bpf_probe_read_kernel(&piddata.nr_free_pages,
  sizeof(*vm_zone_stat_kaddrp),
  &vm_zone_stat_kaddrp[NR_FREE_PAGES]);
  }

libbpf-tools/filelife.bpf.c

@@ -68,7 +68,7 @@ int BPF_KPROBE(kprobe__vfs_unlink, struct inode *dir, struct dentry *dentry)
 
  qs_name_ptr = BPF_CORE_READ(dentry, d_name.name);
  qs_len = BPF_CORE_READ(dentry, d_name.len);
- bpf_probe_read_str(&event.file, sizeof(event.file), qs_name_ptr);
+ bpf_probe_read_kernel_str(&event.file, sizeof(event.file), qs_name_ptr);
  bpf_get_current_comm(&event.task, sizeof(event.task));
  event.delta_ns = delta_ns;
  event.tgid = tgid;

libbpf-tools/runqslower.bpf.c

@@ -89,7 +89,7 @@ int handle__sched_switch(u64 *ctx)
 
  event.pid = pid;
  event.delta_us = delta_us;
- bpf_probe_read_str(&event.task, sizeof(event.task), next->comm);
+ bpf_probe_read_kernel_str(&event.task, sizeof(event.task), next->comm);
 
  /* output */
  bpf_perf_event_output(ctx, &events, BPF_F_CURRENT_CPU,

libbpf-tools/xfsslower.bpf.c

@@ -115,7 +115,7 @@ probe_exit(struct pt_regs *ctx, char type, ssize_t size)
  dentry = BPF_CORE_READ(fp, f_path.dentry);
  qs_len = BPF_CORE_READ(dentry, d_name.len);
  qs_name_ptr = BPF_CORE_READ(dentry, d_name.name);
- bpf_probe_read_str(&event.file, sizeof(event.file), qs_name_ptr);
+ bpf_probe_read_kernel_str(&event.file, sizeof(event.file), qs_name_ptr);
  bpf_get_current_comm(&event.task, sizeof(event.task));
  event.delta_us = delta_us;
  event.end_ns = end_ns;