Merge pull request iovisor#3662 from chenhengqi/enable-warn-unused-vars

libbpf-tools: Enable compilation warnings for BPF programs
weibang6liu · Oct 16, 2021 · d1afbf6 · d1afbf6
2 parents 8b350fd + 531b698
commit d1afbf6
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Showing 9 changed files with 8 additions and 22 deletions.
diff --git a/libbpf-tools/Makefile b/libbpf-tools/Makefile
@@ -104,7 +104,7 @@ $(OUTPUT)/%.skel.h: $(OUTPUT)/%.bpf.o | $(OUTPUT)
 
 $(OUTPUT)/%.bpf.o: %.bpf.c $(LIBBPF_OBJ) $(wildcard %.h) $(ARCH)/vmlinux.h | $(OUTPUT)
  $(call msg,BPF,$@)
- $(Q)$(CLANG) -g -O2 -target bpf -D__TARGET_ARCH_$(ARCH)  \
+ $(Q)$(CLANG) $(CFLAGS) -target bpf -D__TARGET_ARCH_$(ARCH) \
  -I$(ARCH)/ $(INCLUDES) -c $(filter %.c,$^) -o $@ && \
  $(LLVM_STRIP) -g $@
 

diff --git a/libbpf-tools/biopattern.bpf.c b/libbpf-tools/biopattern.bpf.c
@@ -19,7 +19,7 @@ struct {
 SEC("tracepoint/block/block_rq_complete")
 int handle__block_rq_complete(struct trace_event_raw_block_rq_complete *ctx)
 {
- sector_t *last_sectorp, sector = ctx->sector;
+ sector_t sector = ctx->sector;
  struct counter *counterp, zero = {};
  u32 nr_sector = ctx->nr_sector;
  dev_t dev = ctx->dev;

diff --git a/libbpf-tools/biosnoop.bpf.c b/libbpf-tools/biosnoop.bpf.c
@@ -126,7 +126,7 @@ SEC("tp_btf/block_rq_complete")
 int BPF_PROG(block_rq_complete, struct request *rq, int error,
  unsigned int nr_bytes)
 {
- u64 slot, ts = bpf_ktime_get_ns();
+ u64 ts = bpf_ktime_get_ns();
  struct piddata *piddatap;
  struct event event = {};
  struct stage *stagep;

diff --git a/libbpf-tools/biostacks.bpf.c b/libbpf-tools/biostacks.bpf.c
@@ -84,7 +84,6 @@ int BPF_PROG(blk_account_io_done, struct request *rq)
 {
  u64 slot, ts = bpf_ktime_get_ns();
  struct internal_rqinfo *i_rqinfop;
- struct rqinfo *rqinfop;
  struct hist *histp;
  s64 delta;
 

diff --git a/libbpf-tools/filelife.bpf.c b/libbpf-tools/filelife.bpf.c
@@ -57,7 +57,6 @@ int BPF_KPROBE(vfs_unlink, struct inode *dir, struct dentry *dentry)
  const u8 *qs_name_ptr;
  u32 tgid = id >> 32;
  u64 *tsp, delta_ns;
- u32 qs_len;
 
  tsp = bpf_map_lookup_elem(&start, &dentry);
  if (!tsp)
@@ -67,7 +66,6 @@ int BPF_KPROBE(vfs_unlink, struct inode *dir, struct dentry *dentry)
  bpf_map_delete_elem(&start, &dentry);
 
  qs_name_ptr = BPF_CORE_READ(dentry, d_name.name);
- qs_len = BPF_CORE_READ(dentry, d_name.len);
  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;

diff --git a/libbpf-tools/fsdist.bpf.c b/libbpf-tools/fsdist.bpf.c
@@ -37,9 +37,7 @@ static int probe_entry()
 
 static int probe_return(enum fs_file_op op)
 {
- __u64 pid_tgid = bpf_get_current_pid_tgid();
- __u32 pid = pid_tgid >> 32;
- __u32 tid = (__u32)pid_tgid;
+ __u32 tid = (__u32)bpf_get_current_pid_tgid();
  __u64 ts = bpf_ktime_get_ns();
  __u64 *tsp, slot;
  __s64 delta;

diff --git a/libbpf-tools/gethostlatency.bpf.c b/libbpf-tools/gethostlatency.bpf.c
@@ -46,9 +46,7 @@ static int probe_entry(struct pt_regs *ctx)
 
 static int probe_return(struct pt_regs *ctx)
 {
- __u64 pid_tgid = bpf_get_current_pid_tgid();
- __u32 pid = pid_tgid >> 32;
- __u32 tid = (__u32)pid_tgid;
+ __u32 tid = (__u32)bpf_get_current_pid_tgid();
  struct event *eventp;
 
  eventp = bpf_map_lookup_elem(&starts, &tid);

diff --git a/libbpf-tools/ksnoop.bpf.c b/libbpf-tools/ksnoop.bpf.c
@@ -221,16 +221,14 @@ static void output_stashed_traces(struct pt_regs *ctx,
 {
  struct func_stack *func_stack;
  struct trace *trace = NULL;
- __u8 stack_depth, i;
+ __u8 i;
  __u64 task = 0;
 
  task = bpf_get_current_task();
  func_stack = bpf_map_lookup_elem(&ksnoop_func_stack, &task);
  if (!func_stack)
  return;
 
- stack_depth = func_stack->stack_depth;
-
  if (entry) {
  /* iterate from bottom to top of stack, outputting stashed
  * data we find. This corresponds to the set of functions
@@ -294,9 +292,7 @@ static int ksnoop(struct pt_regs *ctx, bool entry)
 {
  void *data_ptr = NULL;
  struct trace *trace;
- struct func *func;
- __u16 trace_len;
- __u64 data, pg;
+ __u64 data;
  __u32 currpid;
  int ret;
  __u8 i;
@@ -305,8 +301,6 @@ static int ksnoop(struct pt_regs *ctx, bool entry)
  if (!trace)
  return 0;
 
- func = &trace->func;
-
  /* make sure we want events from this pid */
  currpid = bpf_get_current_pid_tgid();
  if (trace->filter_pid && trace->filter_pid != currpid)
@@ -399,7 +393,7 @@ static int ksnoop(struct pt_regs *ctx, bool entry)
  if (!ok) {
  clear_trace(trace);
  return 0;
- } 
+ }
  }
 
  if (currtrace->flags & (KSNOOP_F_PTR | KSNOOP_F_MEMBER))

diff --git a/libbpf-tools/syscount.bpf.c b/libbpf-tools/syscount.bpf.c
@@ -62,7 +62,6 @@ int sys_enter(struct trace_event_raw_sys_enter *args)
 SEC("tracepoint/raw_syscalls/sys_exit")
 int sys_exit(struct trace_event_raw_sys_exit *args)
 {
- struct task_struct *current;
  u64 id = bpf_get_current_pid_tgid();
  static const struct data_t zero;
  pid_t pid = id >> 32;