dwarf-unwind.c

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// SPDX-License-Identifier: GPL-2.0
#include <string.h>
#include "perf_regs.h"
#include "thread.h"
#include "map.h"
#include "event.h"
#include "debug.h"
#include "tests/tests.h"

#define STACK_SIZE 8192

static int sample_ustack(struct perf_sample *sample,
             struct thread *thread, u64 *regs)
{
    struct stack_dump *stack = &sample->user_stack;
    struct map *map;
    unsigned long sp;
    u64 stack_size, *buf;

    buf = malloc(STACK_SIZE);
    if (!buf) {
        pr_debug("failed to allocate sample uregs data\n");
        return -1;
    }

    sp = (unsigned long) regs[PERF_REG_ARM_SP];

    map = map_groups__find(thread->mg, (u64)sp);
    if (!map) {
        pr_debug("failed to get stack map\n");
        free(buf);
        return -1;
    }

    stack_size = map->end - sp;
    stack_size = stack_size > STACK_SIZE ? STACK_SIZE : stack_size;

    memcpy(buf, (void *) sp, stack_size);
    stack->data = (char *) buf;
    stack->size = stack_size;
    return 0;
}

int test__arch_unwind_sample(struct perf_sample *sample,
                 struct thread *thread)
{
    struct regs_dump *regs = &sample->user_regs;
    u64 *buf;

    buf = calloc(1, sizeof(u64) * PERF_REGS_MAX);
    if (!buf) {
        pr_debug("failed to allocate sample uregs data\n");
        return -1;
    }

    perf_regs_load(buf);
    regs->abi  = PERF_SAMPLE_REGS_ABI;
    regs->regs = buf;
    regs->mask = PERF_REGS_MASK;

    return sample_ustack(sample, thread, buf);
}