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authorKees Cook <kees+treewide@kernel.org>2026-09-02 15:31:14 -0700
committerKees Cook <kees@kernel.org>2026-09-04 21:37:00 -0700
commit3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch)
treec65086f9bdcd48c6360fb7cb4598bca084da1f32 /samples/bpf/offwaketime.bpf.c
downloadlinux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz
linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'samples/bpf/offwaketime.bpf.c')
-rw-r--r--samples/bpf/offwaketime.bpf.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/samples/bpf/offwaketime.bpf.c b/samples/bpf/offwaketime.bpf.c
new file mode 100644
index 000000000..4a65ba76c
--- /dev/null
+++ b/samples/bpf/offwaketime.bpf.c
@@ -0,0 +1,141 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include "vmlinux.h"
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+#ifndef PERF_MAX_STACK_DEPTH
+#define PERF_MAX_STACK_DEPTH 127
+#endif
+
+#define MINBLOCK_US 1
+#define MAX_ENTRIES 10000
+
+struct key_t {
+ char waker[TASK_COMM_LEN];
+ char target[TASK_COMM_LEN];
+ u32 wret;
+ u32 tret;
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, struct key_t);
+ __type(value, u64);
+ __uint(max_entries, MAX_ENTRIES);
+} counts SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, u32);
+ __type(value, u64);
+ __uint(max_entries, MAX_ENTRIES);
+} start SEC(".maps");
+
+struct wokeby_t {
+ char name[TASK_COMM_LEN];
+ u32 ret;
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, u32);
+ __type(value, struct wokeby_t);
+ __uint(max_entries, MAX_ENTRIES);
+} wokeby SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_STACK_TRACE);
+ __uint(key_size, sizeof(u32));
+ __uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
+ __uint(max_entries, MAX_ENTRIES);
+} stackmap SEC(".maps");
+
+#define STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
+
+SEC("kprobe/try_to_wake_up")
+int waker(struct pt_regs *ctx)
+{
+ struct task_struct *p = (void *)PT_REGS_PARM1_CORE(ctx);
+ u32 pid = BPF_CORE_READ(p, pid);
+ struct wokeby_t woke;
+
+ bpf_get_current_comm(&woke.name, sizeof(woke.name));
+ woke.ret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
+
+ bpf_map_update_elem(&wokeby, &pid, &woke, BPF_ANY);
+ return 0;
+}
+
+static inline int update_counts(void *ctx, u32 pid, u64 delta)
+{
+ struct wokeby_t *woke;
+ u64 zero = 0, *val;
+ struct key_t key;
+
+ __builtin_memset(&key.waker, 0, sizeof(key.waker));
+ bpf_get_current_comm(&key.target, sizeof(key.target));
+ key.tret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
+ key.wret = 0;
+
+ woke = bpf_map_lookup_elem(&wokeby, &pid);
+ if (woke) {
+ key.wret = woke->ret;
+ __builtin_memcpy(&key.waker, woke->name, sizeof(key.waker));
+ bpf_map_delete_elem(&wokeby, &pid);
+ }
+
+ val = bpf_map_lookup_elem(&counts, &key);
+ if (!val) {
+ bpf_map_update_elem(&counts, &key, &zero, BPF_NOEXIST);
+ val = bpf_map_lookup_elem(&counts, &key);
+ if (!val)
+ return 0;
+ }
+ (*val) += delta;
+ return 0;
+}
+
+#if 1
+/* taken from /sys/kernel/tracing/events/sched/sched_switch/format */
+SEC("tracepoint/sched/sched_switch")
+int oncpu(struct trace_event_raw_sched_switch *ctx)
+{
+ /* record previous thread sleep time */
+ u32 pid = ctx->prev_pid;
+#else
+SEC("kprobe.multi/finish_task_switch*")
+int oncpu(struct pt_regs *ctx)
+{
+ struct task_struct *p = (void *)PT_REGS_PARM1_CORE(ctx);
+ /* record previous thread sleep time */
+ u32 pid = BPF_CORE_READ(p, pid);
+#endif
+ u64 delta, ts, *tsp;
+
+ ts = bpf_ktime_get_ns();
+ bpf_map_update_elem(&start, &pid, &ts, BPF_ANY);
+
+ /* calculate current thread's delta time */
+ pid = bpf_get_current_pid_tgid();
+ tsp = bpf_map_lookup_elem(&start, &pid);
+ if (!tsp)
+ /* missed start or filtered */
+ return 0;
+
+ delta = bpf_ktime_get_ns() - *tsp;
+ bpf_map_delete_elem(&start, &pid);
+ delta = delta / 1000;
+ if (delta < MINBLOCK_US)
+ return 0;
+
+ return update_counts(ctx, pid, delta);
+}
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;