scftorture: Count single_rpc offline failures in statistics outputgrafted

scf_torture_stats_print() aggregates each invoker thread's counters
into a local scf_statistics structure before printing, but the
n_single_rpc_ofl field is missing from the aggregation loop.  As a
result, the "single_rpc_ofl" value printed in the statistics line is
always zero, even when smp_call_function_single() invocations for the
RPC test have failed due to offline CPUs and been counted by the
invoker threads.

Add the missing accumulation so that the printed value reflects the
actual counts.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

1 files changed, 339 insertions, 0 deletions

diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
new file mode 100644
index 000000000..1ba1927b5
--- /dev/null
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -0,0 +1,339 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/ftrace.h>
+#if !defined(CONFIG_ARM64) && !defined(CONFIG_PPC32)
+#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_RISCV
+#include <asm/asm.h>
+
+asm (
+"	.pushsection    .text, \"ax\", @progbits\n"
+"	.type		my_tramp1, @function\n"
+"	.globl		my_tramp1\n"
+"   my_tramp1:\n"
+"	addi	sp,sp,-2*"SZREG"\n"
+"	"REG_S"	t0,0*"SZREG"(sp)\n"
+"	"REG_S"	ra,1*"SZREG"(sp)\n"
+"	call	my_direct_func1\n"
+"	"REG_L"	t0,0*"SZREG"(sp)\n"
+"	"REG_L"	ra,1*"SZREG"(sp)\n"
+"	addi	sp,sp,2*"SZREG"\n"
+"	jr	t0\n"
+"	.size		my_tramp1, .-my_tramp1\n"
+"	.type		my_tramp2, @function\n"
+"	.globl		my_tramp2\n"
+
+"   my_tramp2:\n"
+"	addi	sp,sp,-2*"SZREG"\n"
+"	"REG_S"	t0,0*"SZREG"(sp)\n"
+"	"REG_S"	ra,1*"SZREG"(sp)\n"
+"	call	my_direct_func2\n"
+"	"REG_L"	t0,0*"SZREG"(sp)\n"
+"	"REG_L"	ra,1*"SZREG"(sp)\n"
+"	addi	sp,sp,2*"SZREG"\n"
+"	jr	t0\n"
+"	.size		my_tramp2, .-my_tramp2\n"
+"	.popsection\n"
+);
+
+#endif /* CONFIG_RISCV */
+
+#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"
+	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
+"	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	$ra, $sp, 0\n"
+"	ld.d	$t0, $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	$ra, $sp, 0\n"
+"	ld.d	$t0, $sp, 8\n"
+"	addi.d	$sp, $sp, 16\n"
+"	jr	$t0\n"
+"	.size		my_tramp2, .-my_tramp2\n"
+"	.popsection\n"
+);
+
+#endif /* CONFIG_LOONGARCH */
+
+#ifdef CONFIG_PPC
+#include <asm/ppc_asm.h>
+
+#ifdef CONFIG_PPC64
+#define STACK_FRAME_SIZE 48
+#else
+#define STACK_FRAME_SIZE 24
+#endif
+
+#if defined(CONFIG_PPC64_ELF_ABI_V2) && !defined(CONFIG_PPC_KERNEL_PCREL)
+#define PPC64_TOC_SAVE_AND_UPDATE			\
+"	std		2, 24(1)\n"			\
+"	bcl		20, 31, 1f\n"			\
+"   1:	mflr		12\n"				\
+"	ld		2, (99f - 1b)(12)\n"
+#define PPC64_TOC_RESTORE				\
+"	ld		2, 24(1)\n"
+#define PPC64_TOC					\
+"   99:	.quad		.TOC.@tocbase\n"
+#else
+#define PPC64_TOC_SAVE_AND_UPDATE ""
+#define PPC64_TOC_RESTORE ""
+#define PPC64_TOC ""
+#endif
+
+#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE
+#define PPC_FTRACE_RESTORE_LR				\
+	PPC_LL"		0, "__stringify(PPC_LR_STKOFF)"(1)\n"	\
+"	mtlr		0\n"
+#define PPC_FTRACE_RET					\
+"	blr\n"
+#else
+#define PPC_FTRACE_RESTORE_LR				\
+	PPC_LL"		0, "__stringify(PPC_LR_STKOFF)"(1)\n"	\
+"	mtctr		0\n"
+#define PPC_FTRACE_RET					\
+"	mtlr		0\n"				\
+"	bctr\n"
+#endif
+
+asm (
+"	.pushsection	.text, \"ax\", @progbits\n"
+"	.type		my_tramp1, @function\n"
+"	.globl		my_tramp1\n"
+"   my_tramp1:\n"
+	PPC_STL"	0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+	PPC_STLU"	1, -"__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+"	mflr		0\n"
+	PPC_STL"	0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+	PPC_STLU"	1, -"__stringify(STACK_FRAME_SIZE)"(1)\n"
+	PPC64_TOC_SAVE_AND_UPDATE
+"	bl		my_direct_func1\n"
+	PPC64_TOC_RESTORE
+"	addi		1, 1, "__stringify(STACK_FRAME_SIZE)"\n"
+	PPC_FTRACE_RESTORE_LR
+"	addi		1, 1, "__stringify(STACK_FRAME_MIN_SIZE)"\n"
+	PPC_LL"		0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+	PPC_FTRACE_RET
+"	.size		my_tramp1, .-my_tramp1\n"
+
+"	.type		my_tramp2, @function\n"
+"	.globl		my_tramp2\n"
+"   my_tramp2:\n"
+	PPC_STL"	0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+	PPC_STLU"	1, -"__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+"	mflr		0\n"
+	PPC_STL"	0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+	PPC_STLU"	1, -"__stringify(STACK_FRAME_SIZE)"(1)\n"
+	PPC64_TOC_SAVE_AND_UPDATE
+"	bl		my_direct_func2\n"
+	PPC64_TOC_RESTORE
+"	addi		1, 1, "__stringify(STACK_FRAME_SIZE)"\n"
+	PPC_FTRACE_RESTORE_LR
+"	addi		1, 1, "__stringify(STACK_FRAME_MIN_SIZE)"\n"
+	PPC_LL"		0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+	PPC_FTRACE_RET
+	PPC64_TOC
+"	.size		my_tramp2, .-my_tramp2\n"
+"	.popsection\n"
+);
+
+#endif /* CONFIG_PPC */
+
+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");