summaryrefslogtreecommitdiffstats
path: root/samples
diff options
context:
space:
mode:
Diffstat (limited to 'samples')
-rw-r--r--samples/ftrace/Makefile1
-rw-r--r--samples/ftrace/ftrace-direct-modify.c3
-rw-r--r--samples/ftrace/ftrace-direct-multi-modify.c155
-rw-r--r--samples/ftrace/ftrace-direct-too.c3
-rw-r--r--samples/ftrace/ftrace-direct.c2
5 files changed, 164 insertions, 0 deletions
diff --git a/samples/ftrace/Makefile b/samples/ftrace/Makefile
index b9198e2eef28..faf8cdb79c5f 100644
--- a/samples/ftrace/Makefile
+++ b/samples/ftrace/Makefile
@@ -4,6 +4,7 @@ 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-$(CONFIG_SAMPLE_FTRACE_DIRECT_MULTI) += ftrace-direct-multi-modify.o
CFLAGS_sample-trace-array.o := -I$(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
index 690e4a9ff333..2877cb053a82 100644
--- a/samples/ftrace/ftrace-direct-modify.c
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -4,6 +4,9 @@
#include <linux/ftrace.h>
#include <asm/asm-offsets.h>
+extern void my_direct_func1(void);
+extern void my_direct_func2(void);
+
void my_direct_func1(void)
{
trace_printk("my direct func1\n");
diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
new file mode 100644
index 000000000000..6f43a39decd0
--- /dev/null
+++ b/samples/ftrace/ftrace-direct-multi-modify.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/ftrace.h>
+#include <asm/asm-offsets.h>
+
+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
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:"
+" pushq %rbp\n"
+" movq %rsp, %rbp\n"
+" pushq %rdi\n"
+" movq 8(%rbp), %rdi\n"
+" call my_direct_func1\n"
+" popq %rdi\n"
+" leave\n"
+" ret\n"
+" .size my_tramp1, .-my_tramp1\n"
+" .type my_tramp2, @function\n"
+"\n"
+" .globl my_tramp2\n"
+" my_tramp2:"
+" pushq %rbp\n"
+" movq %rsp, %rbp\n"
+" pushq %rdi\n"
+" movq 8(%rbp), %rdi\n"
+" call my_direct_func2\n"
+" popq %rdi\n"
+" leave\n"
+" ret\n"
+" .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 */
+
+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_multi(&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_multi(&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_multi(&direct, my_tramp);
+}
+
+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_multi()");
+MODULE_LICENSE("GPL");
diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
index 6e0de725bf22..b97e5ed46233 100644
--- a/samples/ftrace/ftrace-direct-too.c
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -5,6 +5,9 @@
#include <linux/ftrace.h>
#include <asm/asm-offsets.h>
+extern void my_direct_func(struct vm_area_struct *vma,
+ unsigned long address, unsigned int flags);
+
void my_direct_func(struct vm_area_struct *vma,
unsigned long address, unsigned int flags)
{
diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
index a30aa42ec76a..c918b13edb49 100644
--- a/samples/ftrace/ftrace-direct.c
+++ b/samples/ftrace/ftrace-direct.c
@@ -5,6 +5,8 @@
#include <linux/ftrace.h>
#include <asm/asm-offsets.h>
+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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-27 02:44:39 +0100