unwind-libunwind.c

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// SPDX-License-Identifier: GPL-2.0
#include "unwind.h"
#include "thread.h"
#include "session.h"
#include "debug.h"
#include "env.h"

struct unwind_libunwind_ops __weak *local_unwind_libunwind_ops;
struct unwind_libunwind_ops __weak *x86_32_unwind_libunwind_ops;
struct unwind_libunwind_ops __weak *arm64_unwind_libunwind_ops;

static void unwind__register_ops(struct thread *thread,
              struct unwind_libunwind_ops *ops)
{
    thread->unwind_libunwind_ops = ops;
}

int unwind__prepare_access(struct thread *thread, struct map *map,
               bool *initialized)
{
    const char *arch;
    enum dso_type dso_type;
    struct unwind_libunwind_ops *ops = local_unwind_libunwind_ops;
    int err;

    if (thread->addr_space) {
        pr_debug("unwind: thread map already set, dso=%s\n",
             map->dso->name);
        if (initialized)
            *initialized = true;
        return 0;
    }

    /* env->arch is NULL for live-mode (i.e. perf top) */
    if (!thread->mg->machine->env || !thread->mg->machine->env->arch)
        goto out_register;

    dso_type = dso__type(map->dso, thread->mg->machine);
    if (dso_type == DSO__TYPE_UNKNOWN)
        return 0;

    arch = perf_env__arch(thread->mg->machine->env);

    if (!strcmp(arch, "x86")) {
        if (dso_type != DSO__TYPE_64BIT)
            ops = x86_32_unwind_libunwind_ops;
    } else if (!strcmp(arch, "arm64") || !strcmp(arch, "arm")) {
        if (dso_type == DSO__TYPE_64BIT)
            ops = arm64_unwind_libunwind_ops;
    }

    if (!ops) {
        pr_err("unwind: target platform=%s is not supported\n", arch);
        return 0;
    }
out_register:
    unwind__register_ops(thread, ops);

    err = thread->unwind_libunwind_ops->prepare_access(thread);
    if (initialized)
        *initialized = err ? false : true;
    return err;
}

void unwind__flush_access(struct thread *thread)
{
    if (thread->unwind_libunwind_ops)
        thread->unwind_libunwind_ops->flush_access(thread);
}

void unwind__finish_access(struct thread *thread)
{
    if (thread->unwind_libunwind_ops)
        thread->unwind_libunwind_ops->finish_access(thread);
}

int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
             struct thread *thread,
             struct perf_sample *data, int max_stack)
{
    if (thread->unwind_libunwind_ops)
        return thread->unwind_libunwind_ops->get_entries(cb, arg, thread, data, max_stack);
    return 0;
}