The patch titled
Subject: samples/bpf/test_overhead_kprobe_kern: replace bpf_probe_read_kernel with bpf_probe_read_kernel_str to get task comm
has been added to the -mm tree. Its filename is
samples-bpf-test_overhead_kprobe_kern-replace-bpf_probe_read_kernel-with-bpf_probe_read_kernel_str-to-get-task-comm.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/samples-bpf-test_overhead_kprobe_kern-replace-bpf_probe_read_kernel-with-bpf_probe_read_kernel_str-to-get-task-comm.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/samples-bpf-test_overhead_kprobe_kern-replace-bpf_probe_read_kernel-with-bpf_probe_read_kernel_str-to-get-task-comm.patch
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The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Yafang Shao <laoar.shao@xxxxxxxxx>
Subject: 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@xxxxxxxxx
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx>
Cc: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>
Cc: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx>
Cc: Michal Miroslaw <mirq-linux@xxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
samples/bpf/offwaketime_kern.c | 4 ++--
samples/bpf/test_overhead_kprobe_kern.c | 11 ++++++-----
samples/bpf/test_overhead_tp_kern.c | 5 +++--
3 files changed, 11 insertions(+), 9 deletions(-)
--- a/samples/bpf/offwaketime_kern.c~samples-bpf-test_overhead_kprobe_kern-replace-bpf_probe_read_kernel-with-bpf_probe_read_kernel_str-to-get-task-comm
+++ a/samples/bpf/offwaketime_kern.c
@@ -113,11 +113,11 @@ static inline int update_counts(void *ct
/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */
struct sched_switch_args {
unsigned long long pad;
- char prev_comm[16];
+ char prev_comm[TASK_COMM_LEN];
int prev_pid;
int prev_prio;
long long prev_state;
- char next_comm[16];
+ char next_comm[TASK_COMM_LEN];
int next_pid;
int next_prio;
};
--- a/samples/bpf/test_overhead_kprobe_kern.c~samples-bpf-test_overhead_kprobe_kern-replace-bpf_probe_read_kernel-with-bpf_probe_read_kernel_str-to-get-task-comm
+++ a/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;
--- a/samples/bpf/test_overhead_tp_kern.c~samples-bpf-test_overhead_kprobe_kern-replace-bpf_probe_read_kernel-with-bpf_probe_read_kernel_str-to-get-task-comm
+++ a/samples/bpf/test_overhead_tp_kern.c
@@ -4,6 +4,7 @@
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
+#include <linux/sched.h>
#include <uapi/linux/bpf.h>
#include <bpf/bpf_helpers.h>
@@ -11,8 +12,8 @@
struct task_rename {
__u64 pad;
__u32 pid;
- char oldcomm[16];
- char newcomm[16];
+ char oldcomm[TASK_COMM_LEN];
+ char newcomm[TASK_COMM_LEN];
__u16 oom_score_adj;
};
SEC("tracepoint/task/task_rename")
_
Patches currently in -mm which might be from laoar.shao@xxxxxxxxx are
fs-exec-replace-strlcpy-with-strscpy_pad-in-__set_task_comm.patch
fs-exec-replace-strncpy-with-strscpy_pad-in-__get_task_comm.patch
drivers-infiniband-replace-open-coded-string-copy-with-get_task_comm.patch
fs-binfmt_elf-replace-open-coded-string-copy-with-get_task_comm.patch
samples-bpf-test_overhead_kprobe_kern-replace-bpf_probe_read_kernel-with-bpf_probe_read_kernel_str-to-get-task-comm.patch
tools-bpf-bpftool-skeleton-replace-bpf_probe_read_kernel-with-bpf_probe_read_kernel_str-to-get-task-comm.patch
tools-testing-selftests-bpf-replace-open-coded-16-with-task_comm_len.patch
