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// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd. */
#include <linux/perf_event.h>
#include <linux/uaccess.h>
#include <asm/stacktrace.h>
static bool fill_callchain(void *entry, unsigned long pc)
{
return perf_callchain_store(entry, pc) == 0;
}
/*
* This will be called when the target is in user mode
* This function will only be called when we use
* "PERF_SAMPLE_CALLCHAIN" in
* kernel/events/core.c:perf_prepare_sample()
*
* How to trigger perf_callchain_[user/kernel] :
* $ perf record -e cpu-clock --call-graph fp ./program
* $ perf report --call-graph
*
* On RISC-V platform, the program being sampled and the C library
* need to be compiled with -fno-omit-frame-pointer, otherwise
* the user stack will not contain function frame.
*/
void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
arch_stack_walk_user(fill_callchain, entry, regs);
}
void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
walk_stackframe(NULL, regs, fill_callchain, entry);
}
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