linuxdebug/tools/perf/util/arm64-frame-pointer-unwind-...

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2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0
#include "arm64-frame-pointer-unwind-support.h"
#include "callchain.h"
#include "event.h"
#include "perf_regs.h" // SMPL_REG_MASK
#include "unwind.h"
#define perf_event_arm_regs perf_event_arm64_regs
#include "../../arch/arm64/include/uapi/asm/perf_regs.h"
#undef perf_event_arm_regs
struct entries {
u64 stack[2];
size_t length;
};
static bool get_leaf_frame_caller_enabled(struct perf_sample *sample)
{
return callchain_param.record_mode == CALLCHAIN_FP && sample->user_regs.regs
&& sample->user_regs.mask & SMPL_REG_MASK(PERF_REG_ARM64_LR);
}
static int add_entry(struct unwind_entry *entry, void *arg)
{
struct entries *entries = arg;
entries->stack[entries->length++] = entry->ip;
return 0;
}
u64 get_leaf_frame_caller_aarch64(struct perf_sample *sample, struct thread *thread, int usr_idx)
{
int ret;
struct entries entries = {};
struct regs_dump old_regs = sample->user_regs;
if (!get_leaf_frame_caller_enabled(sample))
return 0;
/*
* If PC and SP are not recorded, get the value of PC from the stack
* and set its mask. SP is not used when doing the unwinding but it
* still needs to be set to prevent failures.
*/
if (!(sample->user_regs.mask & SMPL_REG_MASK(PERF_REG_ARM64_PC))) {
sample->user_regs.cache_mask |= SMPL_REG_MASK(PERF_REG_ARM64_PC);
sample->user_regs.cache_regs[PERF_REG_ARM64_PC] = sample->callchain->ips[usr_idx+1];
}
if (!(sample->user_regs.mask & SMPL_REG_MASK(PERF_REG_ARM64_SP))) {
sample->user_regs.cache_mask |= SMPL_REG_MASK(PERF_REG_ARM64_SP);
sample->user_regs.cache_regs[PERF_REG_ARM64_SP] = 0;
}
ret = unwind__get_entries(add_entry, &entries, thread, sample, 2, true);
sample->user_regs = old_regs;
if (ret || entries.length != 2)
return ret;
return callchain_param.order == ORDER_CALLER ? entries.stack[0] : entries.stack[1];
}