#include <zinnia/percpu.h>
#include <zinnia/usercopy.h>
#include <arch/mem.h>
#include <arch/usercopy.h>

static bool is_user_range(uintptr_t addr, size_t len) {
    if (len == 0)
        return arch_mem_addr_is_user(addr);
    return addr + len > addr && arch_mem_addr_is_user(addr) && arch_mem_addr_is_user(addr + len - 1);
}

bool usercopy_read(void* dst, const __user void* src, size_t len) {
    if (!is_user_range((uintptr_t)src, len))
        return false;

    arch_usercopy_allow(true);
    bool success = arch_usercopy_read(dst, src, len, &percpu_get()->sched.current->usercopy_region);
    arch_usercopy_allow(false);
    return success;
}

bool usercopy_write(__user void* dst, const void* src, size_t len) {
    if (!is_user_range((uintptr_t)dst, len))
        return false;

    arch_usercopy_allow(true);
    bool success = arch_usercopy_write(dst, src, len, &percpu_get()->sched.current->usercopy_region);
    arch_usercopy_allow(false);
    return success;
}

bool usercopy_strlen(const __user char* str, size_t max, size_t* len) {
    if (!arch_mem_addr_is_user((uintptr_t)str))
        return false;

    size_t unused;
    if (len == nullptr)
        len = &unused;

    arch_usercopy_allow(true);
    bool success = arch_usercopy_strlen(str, max, len, &percpu_get()->sched.current->usercopy_region);
    arch_usercopy_allow(false);
    return success;
}