[PATCH v5 11/15] tools/bpf/bpftool: use TASK_COMM_LEN_16 instead of hard-coded 16
From: Yafang Shao <hidden>
Date: 2021-10-21 03:47:28
Also in:
bpf, linux-fsdevel, linux-perf-users, lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [tooling] (bpftool), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Quentin Monnet, Linus Torvalds
Use TASK_COMM_LEN_16 instead of hard-coded 16 to make it more grepable. It uses bpf_probe_read_kernel() to get task comm, which may return a string without nul terminator. We should use bpf_probe_read_kernel_str() instead. Signed-off-by: Yafang Shao <redacted> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Arnaldo Carvalho de Melo <redacted> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Kees Cook <redacted> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Petr Mladek <pmladek@suse.com> --- tools/bpf/bpftool/Makefile | 1 + tools/bpf/bpftool/main.h | 3 ++- tools/bpf/bpftool/skeleton/pid_iter.bpf.c | 4 ++-- tools/bpf/bpftool/skeleton/pid_iter.h | 4 +++- 4 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index d73232be1e99..33fbde84993c 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile@@ -164,6 +164,7 @@ $(OUTPUT)%.bpf.o: skeleton/%.bpf.c $(OUTPUT)vmlinux.h $(LIBBPF) $(QUIET_CLANG)$(CLANG) \ -I$(if $(OUTPUT),$(OUTPUT),.) \ -I$(srctree)/tools/include/uapi/ \ + -I$(srctree)/tools/include/ \ -I$(LIBBPF_PATH) \ -I$(srctree)/tools/lib \ -g -O2 -Wall -target bpf -c $< -o $@ && $(LLVM_STRIP) -g $@
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index 90caa42aac4c..5efa27188f68 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h@@ -12,6 +12,7 @@ #include <linux/compiler.h> #include <linux/kernel.h> #include <linux/hashtable.h> +#include <linux/sched/task.h> #include <tools/libc_compat.h> #include <bpf/libbpf.h>
@@ -124,7 +125,7 @@ struct obj_refs_table { struct obj_ref { int pid; - char comm[16]; + char comm[TASK_COMM_LEN_16]; }; struct obj_refs {
diff --git a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
index d9b420972934..f70702fcb224 100644
--- a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
+++ b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c@@ -71,8 +71,8 @@ int iter(struct bpf_iter__task_file *ctx) e.pid = task->tgid; e.id = get_obj_id(file->private_data, obj_type); - bpf_probe_read_kernel(&e.comm, sizeof(e.comm), - task->group_leader->comm); + bpf_probe_read_kernel_str(&e.comm, sizeof(e.comm), + task->group_leader->comm); bpf_seq_write(ctx->meta->seq, &e, sizeof(e)); return 0;
diff --git a/tools/bpf/bpftool/skeleton/pid_iter.h b/tools/bpf/bpftool/skeleton/pid_iter.h
index 5692cf257adb..675b2916567e 100644
--- a/tools/bpf/bpftool/skeleton/pid_iter.h
+++ b/tools/bpf/bpftool/skeleton/pid_iter.h@@ -3,10 +3,12 @@ #ifndef __PID_ITER_H #define __PID_ITER_H +#include <linux/sched/task.h> + struct pid_iter_entry { __u32 id; int pid; - char comm[16]; + char comm[TASK_COMM_LEN_16]; }; #endif
--
2.17.1