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authorYafang Shao2022-01-19 18:08:33 -0800
committerLinus Torvalds2022-01-20 08:52:53 +0200
commitd068144d3b2cae09062ed936a3865c093ff69590 (patch)
tree42b089f3e3f4a82553c10a095e7192d681e23c7d /samples/bpf/test_overhead_kprobe_kern.c
parent95af469c4f609de011debc08e7a35b45201623a8 (diff)
samples/bpf/test_overhead_kprobe_kern: replace bpf_probe_read_kernel with bpf_probe_read_kernel_str to get task comm
bpf_probe_read_kernel_str() will add a nul terminator to the dst, then we don't care about if the dst size is big enough. This patch also replaces the hard-coded 16 with TASK_COMM_LEN to make it grepable. Link: https://lkml.kernel.org/r/20211120112738.45980-6-laoar.shao@gmail.com Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'samples/bpf/test_overhead_kprobe_kern.c')
-rw-r--r--samples/bpf/test_overhead_kprobe_kern.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/samples/bpf/test_overhead_kprobe_kern.c b/samples/bpf/test_overhead_kprobe_kern.c
index f6d593e47037..8fdd2c9c56b2 100644
--- a/samples/bpf/test_overhead_kprobe_kern.c
+++ b/samples/bpf/test_overhead_kprobe_kern.c
@@ -6,6 +6,7 @@
*/
#include <linux/version.h>
#include <linux/ptrace.h>
+#include <linux/sched.h>
#include <uapi/linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
@@ -22,17 +23,17 @@ int prog(struct pt_regs *ctx)
{
struct signal_struct *signal;
struct task_struct *tsk;
- char oldcomm[16] = {};
- char newcomm[16] = {};
+ char oldcomm[TASK_COMM_LEN] = {};
+ char newcomm[TASK_COMM_LEN] = {};
u16 oom_score_adj;
u32 pid;
tsk = (void *)PT_REGS_PARM1(ctx);
pid = _(tsk->pid);
- bpf_probe_read_kernel(oldcomm, sizeof(oldcomm), &tsk->comm);
- bpf_probe_read_kernel(newcomm, sizeof(newcomm),
- (void *)PT_REGS_PARM2(ctx));
+ bpf_probe_read_kernel_str(oldcomm, sizeof(oldcomm), &tsk->comm);
+ bpf_probe_read_kernel_str(newcomm, sizeof(newcomm),
+ (void *)PT_REGS_PARM2(ctx));
signal = _(tsk->signal);
oom_score_adj = _(signal->oom_score_adj);
return 0;