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-rw-r--r--samples/ftrace/Makefile11
-rw-r--r--samples/ftrace/ftrace-direct-modify.c221
-rw-r--r--samples/ftrace/ftrace-direct-multi-modify.c243
-rw-r--r--samples/ftrace/ftrace-direct-multi.c139
-rw-r--r--samples/ftrace/ftrace-direct-too.c147
-rw-r--r--samples/ftrace/ftrace-direct.c132
-rw-r--r--samples/ftrace/ftrace-ops.c252
-rw-r--r--samples/ftrace/sample-trace-array.c143
-rw-r--r--samples/ftrace/sample-trace-array.h84
9 files changed, 1372 insertions, 0 deletions
diff --git a/samples/ftrace/Makefile b/samples/ftrace/Makefile
new file mode 100644
index 0000000000..589baf2ec4
--- /dev/null
+++ b/samples/ftrace/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct.o
+obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct-too.o
+obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct-modify.o
+obj-$(CONFIG_SAMPLE_FTRACE_DIRECT_MULTI) += ftrace-direct-multi.o
+obj-$(CONFIG_SAMPLE_FTRACE_DIRECT_MULTI) += ftrace-direct-multi-modify.o
+obj-$(CONFIG_SAMPLE_FTRACE_OPS) += ftrace-ops.o
+
+CFLAGS_sample-trace-array.o := -I$(src)
+obj-$(CONFIG_SAMPLE_TRACE_ARRAY) += sample-trace-array.o
diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
new file mode 100644
index 0000000000..e2a6a69352
--- /dev/null
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/ftrace.h>
+#ifndef CONFIG_ARM64
+#include <asm/asm-offsets.h>
+#endif
+
+extern void my_direct_func1(void);
+extern void my_direct_func2(void);
+
+void my_direct_func1(void)
+{
+ trace_printk("my direct func1\n");
+}
+
+void my_direct_func2(void)
+{
+ trace_printk("my direct func2\n");
+}
+
+extern void my_tramp1(void *);
+extern void my_tramp2(void *);
+
+static unsigned long my_ip = (unsigned long)schedule;
+
+#ifdef CONFIG_X86_64
+
+#include <asm/ibt.h>
+#include <asm/nospec-branch.h>
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:"
+ ASM_ENDBR
+" pushq %rbp\n"
+" movq %rsp, %rbp\n"
+ CALL_DEPTH_ACCOUNT
+" call my_direct_func1\n"
+" leave\n"
+" .size my_tramp1, .-my_tramp1\n"
+ ASM_RET
+
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:"
+ ASM_ENDBR
+" pushq %rbp\n"
+" movq %rsp, %rbp\n"
+ CALL_DEPTH_ACCOUNT
+" call my_direct_func2\n"
+" leave\n"
+ ASM_RET
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_X86_64 */
+
+#ifdef CONFIG_S390
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:"
+" lgr %r1,%r15\n"
+" stmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" stg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" aghi %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n"
+" stg %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n"
+" brasl %r14,my_direct_func1\n"
+" aghi %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n"
+" lmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" lg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" lgr %r1,%r0\n"
+" br %r1\n"
+" .size my_tramp1, .-my_tramp1\n"
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:"
+" lgr %r1,%r15\n"
+" stmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" stg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" aghi %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n"
+" stg %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n"
+" brasl %r14,my_direct_func2\n"
+" aghi %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n"
+" lmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" lg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" lgr %r1,%r0\n"
+" br %r1\n"
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_S390 */
+
+#ifdef CONFIG_ARM64
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:"
+" hint 34\n" // bti c
+" sub sp, sp, #16\n"
+" stp x9, x30, [sp]\n"
+" bl my_direct_func1\n"
+" ldp x30, x9, [sp]\n"
+" add sp, sp, #16\n"
+" ret x9\n"
+" .size my_tramp1, .-my_tramp1\n"
+
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:"
+" hint 34\n" // bti c
+" sub sp, sp, #16\n"
+" stp x9, x30, [sp]\n"
+" bl my_direct_func2\n"
+" ldp x30, x9, [sp]\n"
+" add sp, sp, #16\n"
+" ret x9\n"
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_ARM64 */
+
+#ifdef CONFIG_LOONGARCH
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:\n"
+" addi.d $sp, $sp, -16\n"
+" st.d $t0, $sp, 0\n"
+" st.d $ra, $sp, 8\n"
+" bl my_direct_func1\n"
+" ld.d $t0, $sp, 0\n"
+" ld.d $ra, $sp, 8\n"
+" addi.d $sp, $sp, 16\n"
+" jr $t0\n"
+" .size my_tramp1, .-my_tramp1\n"
+
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:\n"
+" addi.d $sp, $sp, -16\n"
+" st.d $t0, $sp, 0\n"
+" st.d $ra, $sp, 8\n"
+" bl my_direct_func2\n"
+" ld.d $t0, $sp, 0\n"
+" ld.d $ra, $sp, 8\n"
+" addi.d $sp, $sp, 16\n"
+" jr $t0\n"
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_LOONGARCH */
+
+static struct ftrace_ops direct;
+
+static unsigned long my_tramp = (unsigned long)my_tramp1;
+static unsigned long tramps[2] = {
+ (unsigned long)my_tramp1,
+ (unsigned long)my_tramp2,
+};
+
+static int simple_thread(void *arg)
+{
+ static int t;
+ int ret = 0;
+
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(2 * HZ);
+
+ if (ret)
+ continue;
+ t ^= 1;
+ ret = modify_ftrace_direct(&direct, tramps[t]);
+ if (!ret)
+ my_tramp = tramps[t];
+ WARN_ON_ONCE(ret);
+ }
+
+ return 0;
+}
+
+static struct task_struct *simple_tsk;
+
+static int __init ftrace_direct_init(void)
+{
+ int ret;
+
+ ftrace_set_filter_ip(&direct, (unsigned long) my_ip, 0, 0);
+ ret = register_ftrace_direct(&direct, my_tramp);
+
+ if (!ret)
+ simple_tsk = kthread_run(simple_thread, NULL, "event-sample-fn");
+ return ret;
+}
+
+static void __exit ftrace_direct_exit(void)
+{
+ kthread_stop(simple_tsk);
+ unregister_ftrace_direct(&direct, my_tramp, true);
+}
+
+module_init(ftrace_direct_init);
+module_exit(ftrace_direct_exit);
+
+MODULE_AUTHOR("Steven Rostedt");
+MODULE_DESCRIPTION("Example use case of using modify_ftrace_direct()");
+MODULE_LICENSE("GPL");
diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
new file mode 100644
index 0000000000..2e349834d6
--- /dev/null
+++ b/samples/ftrace/ftrace-direct-multi-modify.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/ftrace.h>
+#ifndef CONFIG_ARM64
+#include <asm/asm-offsets.h>
+#endif
+
+extern void my_direct_func1(unsigned long ip);
+extern void my_direct_func2(unsigned long ip);
+
+void my_direct_func1(unsigned long ip)
+{
+ trace_printk("my direct func1 ip %lx\n", ip);
+}
+
+void my_direct_func2(unsigned long ip)
+{
+ trace_printk("my direct func2 ip %lx\n", ip);
+}
+
+extern void my_tramp1(void *);
+extern void my_tramp2(void *);
+
+#ifdef CONFIG_X86_64
+
+#include <asm/ibt.h>
+#include <asm/nospec-branch.h>
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:"
+ ASM_ENDBR
+" pushq %rbp\n"
+" movq %rsp, %rbp\n"
+ CALL_DEPTH_ACCOUNT
+" pushq %rdi\n"
+" movq 8(%rbp), %rdi\n"
+" call my_direct_func1\n"
+" popq %rdi\n"
+" leave\n"
+ ASM_RET
+" .size my_tramp1, .-my_tramp1\n"
+
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:"
+ ASM_ENDBR
+" pushq %rbp\n"
+" movq %rsp, %rbp\n"
+ CALL_DEPTH_ACCOUNT
+" pushq %rdi\n"
+" movq 8(%rbp), %rdi\n"
+" call my_direct_func2\n"
+" popq %rdi\n"
+" leave\n"
+ ASM_RET
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_X86_64 */
+
+#ifdef CONFIG_S390
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:"
+" lgr %r1,%r15\n"
+" stmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" stg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" aghi %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n"
+" stg %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n"
+" lgr %r2,%r0\n"
+" brasl %r14,my_direct_func1\n"
+" aghi %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n"
+" lmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" lg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" lgr %r1,%r0\n"
+" br %r1\n"
+" .size my_tramp1, .-my_tramp1\n"
+"\n"
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:"
+" lgr %r1,%r15\n"
+" stmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" stg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" aghi %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n"
+" stg %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n"
+" lgr %r2,%r0\n"
+" brasl %r14,my_direct_func2\n"
+" aghi %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n"
+" lmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" lg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" lgr %r1,%r0\n"
+" br %r1\n"
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_S390 */
+
+#ifdef CONFIG_ARM64
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:"
+" hint 34\n" // bti c
+" sub sp, sp, #32\n"
+" stp x9, x30, [sp]\n"
+" str x0, [sp, #16]\n"
+" mov x0, x30\n"
+" bl my_direct_func1\n"
+" ldp x30, x9, [sp]\n"
+" ldr x0, [sp, #16]\n"
+" add sp, sp, #32\n"
+" ret x9\n"
+" .size my_tramp1, .-my_tramp1\n"
+
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:"
+" hint 34\n" // bti c
+" sub sp, sp, #32\n"
+" stp x9, x30, [sp]\n"
+" str x0, [sp, #16]\n"
+" mov x0, x30\n"
+" bl my_direct_func2\n"
+" ldp x30, x9, [sp]\n"
+" ldr x0, [sp, #16]\n"
+" add sp, sp, #32\n"
+" ret x9\n"
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_ARM64 */
+
+#ifdef CONFIG_LOONGARCH
+#include <asm/asm.h>
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:\n"
+" addi.d $sp, $sp, -32\n"
+" st.d $a0, $sp, 0\n"
+" st.d $t0, $sp, 8\n"
+" st.d $ra, $sp, 16\n"
+" move $a0, $t0\n"
+" bl my_direct_func1\n"
+" ld.d $a0, $sp, 0\n"
+" ld.d $t0, $sp, 8\n"
+" ld.d $ra, $sp, 16\n"
+" addi.d $sp, $sp, 32\n"
+" jr $t0\n"
+" .size my_tramp1, .-my_tramp1\n"
+
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:\n"
+" addi.d $sp, $sp, -32\n"
+" st.d $a0, $sp, 0\n"
+" st.d $t0, $sp, 8\n"
+" st.d $ra, $sp, 16\n"
+" move $a0, $t0\n"
+" bl my_direct_func2\n"
+" ld.d $a0, $sp, 0\n"
+" ld.d $t0, $sp, 8\n"
+" ld.d $ra, $sp, 16\n"
+" addi.d $sp, $sp, 32\n"
+" jr $t0\n"
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_LOONGARCH */
+
+static unsigned long my_tramp = (unsigned long)my_tramp1;
+static unsigned long tramps[2] = {
+ (unsigned long)my_tramp1,
+ (unsigned long)my_tramp2,
+};
+
+static struct ftrace_ops direct;
+
+static int simple_thread(void *arg)
+{
+ static int t;
+ int ret = 0;
+
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(2 * HZ);
+
+ if (ret)
+ continue;
+ t ^= 1;
+ ret = modify_ftrace_direct(&direct, tramps[t]);
+ if (!ret)
+ my_tramp = tramps[t];
+ WARN_ON_ONCE(ret);
+ }
+
+ return 0;
+}
+
+static struct task_struct *simple_tsk;
+
+static int __init ftrace_direct_multi_init(void)
+{
+ int ret;
+
+ ftrace_set_filter_ip(&direct, (unsigned long) wake_up_process, 0, 0);
+ ftrace_set_filter_ip(&direct, (unsigned long) schedule, 0, 0);
+
+ ret = register_ftrace_direct(&direct, my_tramp);
+
+ if (!ret)
+ simple_tsk = kthread_run(simple_thread, NULL, "event-sample-fn");
+ return ret;
+}
+
+static void __exit ftrace_direct_multi_exit(void)
+{
+ kthread_stop(simple_tsk);
+ unregister_ftrace_direct(&direct, my_tramp, true);
+}
+
+module_init(ftrace_direct_multi_init);
+module_exit(ftrace_direct_multi_exit);
+
+MODULE_AUTHOR("Jiri Olsa");
+MODULE_DESCRIPTION("Example use case of using modify_ftrace_direct()");
+MODULE_LICENSE("GPL");
diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
new file mode 100644
index 0000000000..9243dbfe4d
--- /dev/null
+++ b/samples/ftrace/ftrace-direct-multi.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+
+#include <linux/mm.h> /* for handle_mm_fault() */
+#include <linux/ftrace.h>
+#include <linux/sched/stat.h>
+#ifndef CONFIG_ARM64
+#include <asm/asm-offsets.h>
+#endif
+
+extern void my_direct_func(unsigned long ip);
+
+void my_direct_func(unsigned long ip)
+{
+ trace_printk("ip %lx\n", ip);
+}
+
+extern void my_tramp(void *);
+
+#ifdef CONFIG_X86_64
+
+#include <asm/ibt.h>
+#include <asm/nospec-branch.h>
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:"
+ ASM_ENDBR
+" pushq %rbp\n"
+" movq %rsp, %rbp\n"
+ CALL_DEPTH_ACCOUNT
+" pushq %rdi\n"
+" movq 8(%rbp), %rdi\n"
+" call my_direct_func\n"
+" popq %rdi\n"
+" leave\n"
+ ASM_RET
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_X86_64 */
+
+#ifdef CONFIG_S390
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:"
+" lgr %r1,%r15\n"
+" stmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" stg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" aghi %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n"
+" stg %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n"
+" lgr %r2,%r0\n"
+" brasl %r14,my_direct_func\n"
+" aghi %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n"
+" lmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" lg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" lgr %r1,%r0\n"
+" br %r1\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_S390 */
+
+#ifdef CONFIG_ARM64
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:"
+" hint 34\n" // bti c
+" sub sp, sp, #32\n"
+" stp x9, x30, [sp]\n"
+" str x0, [sp, #16]\n"
+" mov x0, x30\n"
+" bl my_direct_func\n"
+" ldp x30, x9, [sp]\n"
+" ldr x0, [sp, #16]\n"
+" add sp, sp, #32\n"
+" ret x9\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_ARM64 */
+
+#ifdef CONFIG_LOONGARCH
+
+#include <asm/asm.h>
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:\n"
+" addi.d $sp, $sp, -32\n"
+" st.d $a0, $sp, 0\n"
+" st.d $t0, $sp, 8\n"
+" st.d $ra, $sp, 16\n"
+" move $a0, $t0\n"
+" bl my_direct_func\n"
+" ld.d $a0, $sp, 0\n"
+" ld.d $t0, $sp, 8\n"
+" ld.d $ra, $sp, 16\n"
+" addi.d $sp, $sp, 32\n"
+" jr $t0\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_LOONGARCH */
+
+static struct ftrace_ops direct;
+
+static int __init ftrace_direct_multi_init(void)
+{
+ ftrace_set_filter_ip(&direct, (unsigned long) wake_up_process, 0, 0);
+ ftrace_set_filter_ip(&direct, (unsigned long) schedule, 0, 0);
+
+ return register_ftrace_direct(&direct, (unsigned long) my_tramp);
+}
+
+static void __exit ftrace_direct_multi_exit(void)
+{
+ unregister_ftrace_direct(&direct, (unsigned long) my_tramp, true);
+}
+
+module_init(ftrace_direct_multi_init);
+module_exit(ftrace_direct_multi_exit);
+
+MODULE_AUTHOR("Jiri Olsa");
+MODULE_DESCRIPTION("Example use case of using register_ftrace_direct_multi()");
+MODULE_LICENSE("GPL");
diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
new file mode 100644
index 0000000000..e39c3563ae
--- /dev/null
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+
+#include <linux/mm.h> /* for handle_mm_fault() */
+#include <linux/ftrace.h>
+#ifndef CONFIG_ARM64
+#include <asm/asm-offsets.h>
+#endif
+
+extern void my_direct_func(struct vm_area_struct *vma, unsigned long address,
+ unsigned int flags, struct pt_regs *regs);
+
+void my_direct_func(struct vm_area_struct *vma, unsigned long address,
+ unsigned int flags, struct pt_regs *regs)
+{
+ trace_printk("handle mm fault vma=%p address=%lx flags=%x regs=%p\n",
+ vma, address, flags, regs);
+}
+
+extern void my_tramp(void *);
+
+#ifdef CONFIG_X86_64
+
+#include <asm/ibt.h>
+#include <asm/nospec-branch.h>
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:"
+ ASM_ENDBR
+" pushq %rbp\n"
+" movq %rsp, %rbp\n"
+ CALL_DEPTH_ACCOUNT
+" pushq %rdi\n"
+" pushq %rsi\n"
+" pushq %rdx\n"
+" pushq %rcx\n"
+" call my_direct_func\n"
+" popq %rcx\n"
+" popq %rdx\n"
+" popq %rsi\n"
+" popq %rdi\n"
+" leave\n"
+ ASM_RET
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_X86_64 */
+
+#ifdef CONFIG_S390
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:"
+" lgr %r1,%r15\n"
+" stmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" stg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" aghi %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n"
+" stg %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n"
+" brasl %r14,my_direct_func\n"
+" aghi %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n"
+" lmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" lg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" lgr %r1,%r0\n"
+" br %r1\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_S390 */
+
+#ifdef CONFIG_ARM64
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:"
+" hint 34\n" // bti c
+" sub sp, sp, #48\n"
+" stp x9, x30, [sp]\n"
+" stp x0, x1, [sp, #16]\n"
+" stp x2, x3, [sp, #32]\n"
+" bl my_direct_func\n"
+" ldp x30, x9, [sp]\n"
+" ldp x0, x1, [sp, #16]\n"
+" ldp x2, x3, [sp, #32]\n"
+" add sp, sp, #48\n"
+" ret x9\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_ARM64 */
+
+#ifdef CONFIG_LOONGARCH
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:\n"
+" addi.d $sp, $sp, -48\n"
+" st.d $a0, $sp, 0\n"
+" st.d $a1, $sp, 8\n"
+" st.d $a2, $sp, 16\n"
+" st.d $t0, $sp, 24\n"
+" st.d $ra, $sp, 32\n"
+" bl my_direct_func\n"
+" ld.d $a0, $sp, 0\n"
+" ld.d $a1, $sp, 8\n"
+" ld.d $a2, $sp, 16\n"
+" ld.d $t0, $sp, 24\n"
+" ld.d $ra, $sp, 32\n"
+" addi.d $sp, $sp, 48\n"
+" jr $t0\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_LOONGARCH */
+
+static struct ftrace_ops direct;
+
+static int __init ftrace_direct_init(void)
+{
+ ftrace_set_filter_ip(&direct, (unsigned long) handle_mm_fault, 0, 0);
+
+ return register_ftrace_direct(&direct, (unsigned long) my_tramp);
+}
+
+static void __exit ftrace_direct_exit(void)
+{
+ unregister_ftrace_direct(&direct, (unsigned long)my_tramp, true);
+}
+
+module_init(ftrace_direct_init);
+module_exit(ftrace_direct_exit);
+
+MODULE_AUTHOR("Steven Rostedt");
+MODULE_DESCRIPTION("Another example use case of using register_ftrace_direct()");
+MODULE_LICENSE("GPL");
diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
new file mode 100644
index 0000000000..32c477da1e
--- /dev/null
+++ b/samples/ftrace/ftrace-direct.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+
+#include <linux/sched.h> /* for wake_up_process() */
+#include <linux/ftrace.h>
+#ifndef CONFIG_ARM64
+#include <asm/asm-offsets.h>
+#endif
+
+extern void my_direct_func(struct task_struct *p);
+
+void my_direct_func(struct task_struct *p)
+{
+ trace_printk("waking up %s-%d\n", p->comm, p->pid);
+}
+
+extern void my_tramp(void *);
+
+#ifdef CONFIG_X86_64
+
+#include <asm/ibt.h>
+#include <asm/nospec-branch.h>
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:"
+ ASM_ENDBR
+" pushq %rbp\n"
+" movq %rsp, %rbp\n"
+ CALL_DEPTH_ACCOUNT
+" pushq %rdi\n"
+" call my_direct_func\n"
+" popq %rdi\n"
+" leave\n"
+ ASM_RET
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_X86_64 */
+
+#ifdef CONFIG_S390
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:"
+" lgr %r1,%r15\n"
+" stmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" stg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" aghi %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n"
+" stg %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n"
+" brasl %r14,my_direct_func\n"
+" aghi %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n"
+" lmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+" lg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+" lgr %r1,%r0\n"
+" br %r1\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_S390 */
+
+#ifdef CONFIG_ARM64
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:"
+" hint 34\n" // bti c
+" sub sp, sp, #32\n"
+" stp x9, x30, [sp]\n"
+" str x0, [sp, #16]\n"
+" bl my_direct_func\n"
+" ldp x30, x9, [sp]\n"
+" ldr x0, [sp, #16]\n"
+" add sp, sp, #32\n"
+" ret x9\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_ARM64 */
+
+#ifdef CONFIG_LOONGARCH
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:\n"
+" addi.d $sp, $sp, -32\n"
+" st.d $a0, $sp, 0\n"
+" st.d $t0, $sp, 8\n"
+" st.d $ra, $sp, 16\n"
+" bl my_direct_func\n"
+" ld.d $a0, $sp, 0\n"
+" ld.d $t0, $sp, 8\n"
+" ld.d $ra, $sp, 16\n"
+" addi.d $sp, $sp, 32\n"
+" jr $t0\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_LOONGARCH */
+
+static struct ftrace_ops direct;
+
+static int __init ftrace_direct_init(void)
+{
+ ftrace_set_filter_ip(&direct, (unsigned long) wake_up_process, 0, 0);
+
+ return register_ftrace_direct(&direct, (unsigned long) my_tramp);
+}
+
+static void __exit ftrace_direct_exit(void)
+{
+ unregister_ftrace_direct(&direct, (unsigned long)my_tramp, true);
+}
+
+module_init(ftrace_direct_init);
+module_exit(ftrace_direct_exit);
+
+MODULE_AUTHOR("Steven Rostedt");
+MODULE_DESCRIPTION("Example use case of using register_ftrace_direct()");
+MODULE_LICENSE("GPL");
diff --git a/samples/ftrace/ftrace-ops.c b/samples/ftrace/ftrace-ops.c
new file mode 100644
index 0000000000..68d6685c80
--- /dev/null
+++ b/samples/ftrace/ftrace-ops.c
@@ -0,0 +1,252 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/ftrace.h>
+#include <linux/ktime.h>
+#include <linux/module.h>
+
+#include <asm/barrier.h>
+
+/*
+ * Arbitrary large value chosen to be sufficiently large to minimize noise but
+ * sufficiently small to complete quickly.
+ */
+static unsigned int nr_function_calls = 100000;
+module_param(nr_function_calls, uint, 0);
+MODULE_PARM_DESC(nr_function_calls, "How many times to call the relevant tracee");
+
+/*
+ * The number of ops associated with a call site affects whether a tracer can
+ * be called directly or whether it's necessary to go via the list func, which
+ * can be significantly more expensive.
+ */
+static unsigned int nr_ops_relevant = 1;
+module_param(nr_ops_relevant, uint, 0);
+MODULE_PARM_DESC(nr_ops_relevant, "How many ftrace_ops to associate with the relevant tracee");
+
+/*
+ * On architectures where all call sites share the same trampoline, having
+ * tracers enabled for distinct functions can force the use of the list func
+ * and incur overhead for all call sites.
+ */
+static unsigned int nr_ops_irrelevant;
+module_param(nr_ops_irrelevant, uint, 0);
+MODULE_PARM_DESC(nr_ops_irrelevant, "How many ftrace_ops to associate with the irrelevant tracee");
+
+/*
+ * On architectures with DYNAMIC_FTRACE_WITH_REGS, saving the full pt_regs can
+ * be more expensive than only saving the minimal necessary regs.
+ */
+static bool save_regs;
+module_param(save_regs, bool, 0);
+MODULE_PARM_DESC(save_regs, "Register ops with FTRACE_OPS_FL_SAVE_REGS (save all registers in the trampoline)");
+
+static bool assist_recursion;
+module_param(assist_recursion, bool, 0);
+MODULE_PARM_DESC(assist_reursion, "Register ops with FTRACE_OPS_FL_RECURSION");
+
+static bool assist_rcu;
+module_param(assist_rcu, bool, 0);
+MODULE_PARM_DESC(assist_reursion, "Register ops with FTRACE_OPS_FL_RCU");
+
+/*
+ * By default, a trivial tracer is used which immediately returns to mimimize
+ * overhead. Sometimes a consistency check using a more expensive tracer is
+ * desireable.
+ */
+static bool check_count;
+module_param(check_count, bool, 0);
+MODULE_PARM_DESC(check_count, "Check that tracers are called the expected number of times\n");
+
+/*
+ * Usually it's not interesting to leave the ops registered after the test
+ * runs, but sometimes it can be useful to leave them registered so that they
+ * can be inspected through the tracefs 'enabled_functions' file.
+ */
+static bool persist;
+module_param(persist, bool, 0);
+MODULE_PARM_DESC(persist, "Successfully load module and leave ftrace ops registered after test completes\n");
+
+/*
+ * Marked as noinline to ensure that an out-of-line traceable copy is
+ * generated by the compiler.
+ *
+ * The barrier() ensures the compiler won't elide calls by determining there
+ * are no side-effects.
+ */
+static noinline void tracee_relevant(void)
+{
+ barrier();
+}
+
+/*
+ * Marked as noinline to ensure that an out-of-line traceable copy is
+ * generated by the compiler.
+ *
+ * The barrier() ensures the compiler won't elide calls by determining there
+ * are no side-effects.
+ */
+static noinline void tracee_irrelevant(void)
+{
+ barrier();
+}
+
+struct sample_ops {
+ struct ftrace_ops ops;
+ unsigned int count;
+};
+
+static void ops_func_nop(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op,
+ struct ftrace_regs *fregs)
+{
+ /* do nothing */
+}
+
+static void ops_func_count(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op,
+ struct ftrace_regs *fregs)
+{
+ struct sample_ops *self;
+
+ self = container_of(op, struct sample_ops, ops);
+ self->count++;
+}
+
+static struct sample_ops *ops_relevant;
+static struct sample_ops *ops_irrelevant;
+
+static struct sample_ops *ops_alloc_init(void *tracee, ftrace_func_t func,
+ unsigned long flags, int nr)
+{
+ struct sample_ops *ops;
+
+ ops = kcalloc(nr, sizeof(*ops), GFP_KERNEL);
+ if (WARN_ON_ONCE(!ops))
+ return NULL;
+
+ for (unsigned int i = 0; i < nr; i++) {
+ ops[i].ops.func = func;
+ ops[i].ops.flags = flags;
+ WARN_ON_ONCE(ftrace_set_filter_ip(&ops[i].ops, (unsigned long)tracee, 0, 0));
+ WARN_ON_ONCE(register_ftrace_function(&ops[i].ops));
+ }
+
+ return ops;
+}
+
+static void ops_destroy(struct sample_ops *ops, int nr)
+{
+ if (!ops)
+ return;
+
+ for (unsigned int i = 0; i < nr; i++) {
+ WARN_ON_ONCE(unregister_ftrace_function(&ops[i].ops));
+ ftrace_free_filter(&ops[i].ops);
+ }
+
+ kfree(ops);
+}
+
+static void ops_check(struct sample_ops *ops, int nr,
+ unsigned int expected_count)
+{
+ if (!ops || !check_count)
+ return;
+
+ for (unsigned int i = 0; i < nr; i++) {
+ if (ops->count == expected_count)
+ continue;
+ pr_warn("Counter called %u times (expected %u)\n",
+ ops->count, expected_count);
+ }
+}
+
+static ftrace_func_t tracer_relevant = ops_func_nop;
+static ftrace_func_t tracer_irrelevant = ops_func_nop;
+
+static int __init ftrace_ops_sample_init(void)
+{
+ unsigned long flags = 0;
+ ktime_t start, end;
+ u64 period;
+
+ if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && save_regs) {
+ pr_info("this kernel does not support saving registers\n");
+ save_regs = false;
+ } else if (save_regs) {
+ flags |= FTRACE_OPS_FL_SAVE_REGS;
+ }
+
+ if (assist_recursion)
+ flags |= FTRACE_OPS_FL_RECURSION;
+
+ if (assist_rcu)
+ flags |= FTRACE_OPS_FL_RCU;
+
+ if (check_count) {
+ tracer_relevant = ops_func_count;
+ tracer_irrelevant = ops_func_count;
+ }
+
+ pr_info("registering:\n"
+ " relevant ops: %u\n"
+ " tracee: %ps\n"
+ " tracer: %ps\n"
+ " irrelevant ops: %u\n"
+ " tracee: %ps\n"
+ " tracer: %ps\n"
+ " saving registers: %s\n"
+ " assist recursion: %s\n"
+ " assist RCU: %s\n",
+ nr_ops_relevant, tracee_relevant, tracer_relevant,
+ nr_ops_irrelevant, tracee_irrelevant, tracer_irrelevant,
+ save_regs ? "YES" : "NO",
+ assist_recursion ? "YES" : "NO",
+ assist_rcu ? "YES" : "NO");
+
+ ops_relevant = ops_alloc_init(tracee_relevant, tracer_relevant,
+ flags, nr_ops_relevant);
+ ops_irrelevant = ops_alloc_init(tracee_irrelevant, tracer_irrelevant,
+ flags, nr_ops_irrelevant);
+
+ start = ktime_get();
+ for (unsigned int i = 0; i < nr_function_calls; i++)
+ tracee_relevant();
+ end = ktime_get();
+
+ ops_check(ops_relevant, nr_ops_relevant, nr_function_calls);
+ ops_check(ops_irrelevant, nr_ops_irrelevant, 0);
+
+ period = ktime_to_ns(ktime_sub(end, start));
+
+ pr_info("Attempted %u calls to %ps in %lluns (%lluns / call)\n",
+ nr_function_calls, tracee_relevant,
+ period, div_u64(period, nr_function_calls));
+
+ if (persist)
+ return 0;
+
+ ops_destroy(ops_relevant, nr_ops_relevant);
+ ops_destroy(ops_irrelevant, nr_ops_irrelevant);
+
+ /*
+ * The benchmark completed sucessfully, but there's no reason to keep
+ * the module around. Return an error do the user doesn't have to
+ * manually unload the module.
+ */
+ return -EINVAL;
+}
+module_init(ftrace_ops_sample_init);
+
+static void __exit ftrace_ops_sample_exit(void)
+{
+ ops_destroy(ops_relevant, nr_ops_relevant);
+ ops_destroy(ops_irrelevant, nr_ops_irrelevant);
+}
+module_exit(ftrace_ops_sample_exit);
+
+MODULE_AUTHOR("Mark Rutland");
+MODULE_DESCRIPTION("Example of using custom ftrace_ops");
+MODULE_LICENSE("GPL");
diff --git a/samples/ftrace/sample-trace-array.c b/samples/ftrace/sample-trace-array.c
new file mode 100644
index 0000000000..6aba02a31c
--- /dev/null
+++ b/samples/ftrace/sample-trace-array.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/trace.h>
+#include <linux/trace_events.h>
+#include <linux/timer.h>
+#include <linux/err.h>
+#include <linux/jiffies.h>
+#include <linux/workqueue.h>
+
+/*
+ * Any file that uses trace points, must include the header.
+ * But only one file, must include the header by defining
+ * CREATE_TRACE_POINTS first. This will make the C code that
+ * creates the handles for the trace points.
+ */
+#define CREATE_TRACE_POINTS
+#include "sample-trace-array.h"
+
+struct trace_array *tr;
+static void mytimer_handler(struct timer_list *unused);
+static struct task_struct *simple_tsk;
+
+static void trace_work_fn(struct work_struct *work)
+{
+ /*
+ * Disable tracing for event "sample_event".
+ */
+ trace_array_set_clr_event(tr, "sample-subsystem", "sample_event",
+ false);
+}
+static DECLARE_WORK(trace_work, trace_work_fn);
+
+/*
+ * mytimer: Timer setup to disable tracing for event "sample_event". This
+ * timer is only for the purposes of the sample module to demonstrate access of
+ * Ftrace instances from within kernel.
+ */
+static DEFINE_TIMER(mytimer, mytimer_handler);
+
+static void mytimer_handler(struct timer_list *unused)
+{
+ schedule_work(&trace_work);
+}
+
+static void simple_thread_func(int count)
+{
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(HZ);
+
+ /*
+ * Printing count value using trace_array_printk() - trace_printk()
+ * equivalent for the instance buffers.
+ */
+ trace_array_printk(tr, _THIS_IP_, "trace_array_printk: count=%d\n",
+ count);
+ /*
+ * Tracepoint for event "sample_event". This will print the
+ * current value of count and current jiffies.
+ */
+ trace_sample_event(count, jiffies);
+}
+
+static int simple_thread(void *arg)
+{
+ int count = 0;
+ unsigned long delay = msecs_to_jiffies(5000);
+
+ /*
+ * Enable tracing for "sample_event".
+ */
+ trace_array_set_clr_event(tr, "sample-subsystem", "sample_event", true);
+
+ /*
+ * Adding timer - mytimer. This timer will disable tracing after
+ * delay seconds.
+ *
+ */
+ add_timer(&mytimer);
+ mod_timer(&mytimer, jiffies+delay);
+
+ while (!kthread_should_stop())
+ simple_thread_func(count++);
+
+ del_timer(&mytimer);
+ cancel_work_sync(&trace_work);
+
+ /*
+ * trace_array_put() decrements the reference counter associated with
+ * the trace array - "tr". We are done using the trace array, hence
+ * decrement the reference counter so that it can be destroyed using
+ * trace_array_destroy().
+ */
+ trace_array_put(tr);
+
+ return 0;
+}
+
+static int __init sample_trace_array_init(void)
+{
+ /*
+ * Return a pointer to the trace array with name "sample-instance" if it
+ * exists, else create a new trace array.
+ *
+ * NOTE: This function increments the reference counter
+ * associated with the trace array - "tr".
+ */
+ tr = trace_array_get_by_name("sample-instance");
+
+ if (!tr)
+ return -1;
+ /*
+ * If context specific per-cpu buffers havent already been allocated.
+ */
+ trace_printk_init_buffers();
+
+ simple_tsk = kthread_run(simple_thread, NULL, "sample-instance");
+ if (IS_ERR(simple_tsk)) {
+ trace_array_put(tr);
+ trace_array_destroy(tr);
+ return -1;
+ }
+
+ return 0;
+}
+
+static void __exit sample_trace_array_exit(void)
+{
+ kthread_stop(simple_tsk);
+
+ /*
+ * We are unloading our module and no longer require the trace array.
+ * Remove/destroy "tr" using trace_array_destroy()
+ */
+ trace_array_destroy(tr);
+}
+
+module_init(sample_trace_array_init);
+module_exit(sample_trace_array_exit);
+
+MODULE_AUTHOR("Divya Indi");
+MODULE_DESCRIPTION("Sample module for kernel access to Ftrace instances");
+MODULE_LICENSE("GPL");
diff --git a/samples/ftrace/sample-trace-array.h b/samples/ftrace/sample-trace-array.h
new file mode 100644
index 0000000000..6f89624281
--- /dev/null
+++ b/samples/ftrace/sample-trace-array.h
@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * If TRACE_SYSTEM is defined, that will be the directory created
+ * in the ftrace directory under /sys/kernel/tracing/events/<system>
+ *
+ * The define_trace.h below will also look for a file name of
+ * TRACE_SYSTEM.h where TRACE_SYSTEM is what is defined here.
+ * In this case, it would look for sample-trace.h
+ *
+ * If the header name will be different than the system name
+ * (as in this case), then you can override the header name that
+ * define_trace.h will look up by defining TRACE_INCLUDE_FILE
+ *
+ * This file is called sample-trace-array.h but we want the system
+ * to be called "sample-subsystem". Therefore we must define the name of this
+ * file:
+ *
+ * #define TRACE_INCLUDE_FILE sample-trace-array
+ *
+ * As we do in the bottom of this file.
+ *
+ * Notice that TRACE_SYSTEM should be defined outside of #if
+ * protection, just like TRACE_INCLUDE_FILE.
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM sample-subsystem
+
+/*
+ * TRACE_SYSTEM is expected to be a C valid variable (alpha-numeric
+ * and underscore), although it may start with numbers. If for some
+ * reason it is not, you need to add the following lines:
+ */
+#undef TRACE_SYSTEM_VAR
+#define TRACE_SYSTEM_VAR sample_subsystem
+
+/*
+ * But the above is only needed if TRACE_SYSTEM is not alpha-numeric
+ * and underscored. By default, TRACE_SYSTEM_VAR will be equal to
+ * TRACE_SYSTEM. As TRACE_SYSTEM_VAR must be alpha-numeric, if
+ * TRACE_SYSTEM is not, then TRACE_SYSTEM_VAR must be defined with
+ * only alpha-numeric and underscores.
+ *
+ * The TRACE_SYSTEM_VAR is only used internally and not visible to
+ * user space.
+ */
+
+/*
+ * Notice that this file is not protected like a normal header.
+ * We also must allow for rereading of this file. The
+ *
+ * || defined(TRACE_HEADER_MULTI_READ)
+ *
+ * serves this purpose.
+ */
+#if !defined(_SAMPLE_TRACE_ARRAY_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _SAMPLE_TRACE_ARRAY_H
+
+#include <linux/tracepoint.h>
+TRACE_EVENT(sample_event,
+
+ TP_PROTO(int count, unsigned long time),
+
+ TP_ARGS(count, time),
+
+ TP_STRUCT__entry(
+ __field(int, count)
+ __field(unsigned long, time)
+ ),
+
+ TP_fast_assign(
+ __entry->count = count;
+ __entry->time = time;
+ ),
+
+ TP_printk("count value=%d at jiffies=%lu", __entry->count,
+ __entry->time)
+ );
+#endif
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE sample-trace-array
+#include <trace/define_trace.h>
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 15:09:25 +0000