fix uprobe examples to read correct argument

linux-kern · Jul 25, 2016 · eb1b70d · eb1b70d
1 parent 239e863
commit eb1b70d
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Showing 2 changed files with 4 additions and 4 deletions.
diff --git a/examples/tracing/strlen_count.py b/examples/tracing/strlen_count.py
@@ -24,13 +24,13 @@
 BPF_HASH(counts, struct key_t);
 
 int count(struct pt_regs *ctx) {
- if (!PT_REGS_PARM2(ctx))
+ if (!PT_REGS_PARM1(ctx))
  return 0;
 
  struct key_t key = {};
  u64 zero = 0, *val;
 
- bpf_probe_read(&key.c, sizeof(key.c), (void *)PT_REGS_PARM2(ctx));
+ bpf_probe_read(&key.c, sizeof(key.c), (void *)PT_REGS_PARM1(ctx));
  val = counts.lookup_or_init(&key, &zero);
  (*val)++;
  return 0;

diff --git a/examples/tracing/strlen_snoop.py b/examples/tracing/strlen_snoop.py
@@ -26,15 +26,15 @@
 bpf_text = """
 #include <uapi/linux/ptrace.h>
 int printarg(struct pt_regs *ctx) {
- if (!PT_REGS_PARM2(ctx))
+ if (!PT_REGS_PARM1(ctx))
  return 0;
 
  u32 pid = bpf_get_current_pid_tgid();
  if (pid != PID)
  return 0;
 
  char str[80] = {};
- bpf_probe_read(&str, sizeof(str), (void *)PT_REGS_PARM2(ctx));
+ bpf_probe_read(&str, sizeof(str), (void *)PT_REGS_PARM1(ctx));
  bpf_trace_printk("%s\\n", &str);
 
  return 0;