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-rw-r--r--samples/ftrace/ftrace-direct-multi.c139
1 files changed, 139 insertions, 0 deletions
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");