target_ulong do_common_semihosting()

in semihosting/arm-compat-semi.c [814:1290]


target_ulong do_common_semihosting(CPUState *cs)
{
    CPUArchState *env = cs->env_ptr;
    target_ulong args;
    target_ulong arg0, arg1, arg2, arg3;
    target_ulong ul_ret;
    char * s;
    int nr;
    uint32_t ret;
    uint32_t len;
    GuestFD *gf;
    int64_t elapsed;

    (void) env; /* Used implicitly by arm lock_user macro */
    nr = common_semi_arg(cs, 0) & 0xffffffffU;
    args = common_semi_arg(cs, 1);

    switch (nr) {
    case TARGET_SYS_OPEN:
    {
        int guestfd;

        GET_ARG(0);
        GET_ARG(1);
        GET_ARG(2);
        s = lock_user_string(arg0);
        if (!s) {
            errno = EFAULT;
            return set_swi_errno(cs, -1);
        }
        if (arg1 >= 12) {
            unlock_user(s, arg0, 0);
            errno = EINVAL;
            return set_swi_errno(cs, -1);
        }

        guestfd = alloc_guestfd();
        if (guestfd < 0) {
            unlock_user(s, arg0, 0);
            errno = EMFILE;
            return set_swi_errno(cs, -1);
        }

        if (strcmp(s, ":tt") == 0) {
            int result_fileno;

            /*
             * We implement SH_EXT_STDOUT_STDERR, so:
             *  open for read == stdin
             *  open for write == stdout
             *  open for append == stderr
             */
            if (arg1 < 4) {
                result_fileno = STDIN_FILENO;
            } else if (arg1 < 8) {
                result_fileno = STDOUT_FILENO;
            } else {
                result_fileno = STDERR_FILENO;
            }
            associate_guestfd(guestfd, result_fileno);
            unlock_user(s, arg0, 0);
            return guestfd;
        }
        if (strcmp(s, ":semihosting-features") == 0) {
            unlock_user(s, arg0, 0);
            /* We must fail opens for modes other than 0 ('r') or 1 ('rb') */
            if (arg1 != 0 && arg1 != 1) {
                dealloc_guestfd(guestfd);
                errno = EACCES;
                return set_swi_errno(cs, -1);
            }
            init_featurefile_guestfd(guestfd);
            return guestfd;
        }

        if (use_gdb_syscalls()) {
            common_semi_open_guestfd = guestfd;
            ret = common_semi_gdb_syscall(cs, common_semi_open_cb,
                                          "open,%s,%x,1a4", arg0, (int)arg2 + 1,
                                          gdb_open_modeflags[arg1]);
        } else {
            ret = set_swi_errno(cs, open(s, open_modeflags[arg1], 0644));
            if (ret == (uint32_t)-1) {
                dealloc_guestfd(guestfd);
            } else {
                associate_guestfd(guestfd, ret);
                ret = guestfd;
            }
        }
        unlock_user(s, arg0, 0);
        return ret;
    }
    case TARGET_SYS_CLOSE:
        GET_ARG(0);

        gf = get_guestfd(arg0);
        if (!gf) {
            errno = EBADF;
            return set_swi_errno(cs, -1);
        }

        ret = guestfd_fns[gf->type].closefn(cs, gf);
        dealloc_guestfd(arg0);
        return ret;
    case TARGET_SYS_WRITEC:
        qemu_semihosting_console_outc(cs->env_ptr, args);
        return 0xdeadbeef;
    case TARGET_SYS_WRITE0:
        return qemu_semihosting_console_outs(cs->env_ptr, args);
    case TARGET_SYS_WRITE:
        GET_ARG(0);
        GET_ARG(1);
        GET_ARG(2);
        len = arg2;

        gf = get_guestfd(arg0);
        if (!gf) {
            errno = EBADF;
            return set_swi_errno(cs, -1);
        }

        return guestfd_fns[gf->type].writefn(cs, gf, arg1, len);
    case TARGET_SYS_READ:
        GET_ARG(0);
        GET_ARG(1);
        GET_ARG(2);
        len = arg2;

        gf = get_guestfd(arg0);
        if (!gf) {
            errno = EBADF;
            return set_swi_errno(cs, -1);
        }

        return guestfd_fns[gf->type].readfn(cs, gf, arg1, len);
    case TARGET_SYS_READC:
        return qemu_semihosting_console_inc(cs->env_ptr);
    case TARGET_SYS_ISERROR:
        GET_ARG(0);
        return (target_long) arg0 < 0 ? 1 : 0;
    case TARGET_SYS_ISTTY:
        GET_ARG(0);

        gf = get_guestfd(arg0);
        if (!gf) {
            errno = EBADF;
            return set_swi_errno(cs, -1);
        }

        return guestfd_fns[gf->type].isattyfn(cs, gf);
    case TARGET_SYS_SEEK:
        GET_ARG(0);
        GET_ARG(1);

        gf = get_guestfd(arg0);
        if (!gf) {
            errno = EBADF;
            return set_swi_errno(cs, -1);
        }

        return guestfd_fns[gf->type].seekfn(cs, gf, arg1);
    case TARGET_SYS_FLEN:
        GET_ARG(0);

        gf = get_guestfd(arg0);
        if (!gf) {
            errno = EBADF;
            return set_swi_errno(cs, -1);
        }

        return guestfd_fns[gf->type].flenfn(cs, gf);
    case TARGET_SYS_TMPNAM:
        GET_ARG(0);
        GET_ARG(1);
        GET_ARG(2);
        if (asprintf(&s, "/tmp/qemu-%x%02x", getpid(),
                     (int) (arg1 & 0xff)) < 0) {
            return -1;
        }
        ul_ret = (target_ulong) -1;

        /* Make sure there's enough space in the buffer */
        if (strlen(s) < arg2) {
            char *output = lock_user(VERIFY_WRITE, arg0, arg2, 0);
            strcpy(output, s);
            unlock_user(output, arg0, arg2);
            ul_ret = 0;
        }
        free(s);
        return ul_ret;
    case TARGET_SYS_REMOVE:
        GET_ARG(0);
        GET_ARG(1);
        if (use_gdb_syscalls()) {
            ret = common_semi_gdb_syscall(cs, common_semi_cb, "unlink,%s",
                                          arg0, (int)arg1 + 1);
        } else {
            s = lock_user_string(arg0);
            if (!s) {
                errno = EFAULT;
                return set_swi_errno(cs, -1);
            }
            ret =  set_swi_errno(cs, remove(s));
            unlock_user(s, arg0, 0);
        }
        return ret;
    case TARGET_SYS_RENAME:
        GET_ARG(0);
        GET_ARG(1);
        GET_ARG(2);
        GET_ARG(3);
        if (use_gdb_syscalls()) {
            return common_semi_gdb_syscall(cs, common_semi_cb, "rename,%s,%s",
                                           arg0, (int)arg1 + 1, arg2,
                                           (int)arg3 + 1);
        } else {
            char *s2;
            s = lock_user_string(arg0);
            s2 = lock_user_string(arg2);
            if (!s || !s2) {
                errno = EFAULT;
                ret = set_swi_errno(cs, -1);
            } else {
                ret = set_swi_errno(cs, rename(s, s2));
            }
            if (s2)
                unlock_user(s2, arg2, 0);
            if (s)
                unlock_user(s, arg0, 0);
            return ret;
        }
    case TARGET_SYS_CLOCK:
        return clock() / (CLOCKS_PER_SEC / 100);
    case TARGET_SYS_TIME:
        return set_swi_errno(cs, time(NULL));
    case TARGET_SYS_SYSTEM:
        GET_ARG(0);
        GET_ARG(1);
        if (use_gdb_syscalls()) {
            return common_semi_gdb_syscall(cs, common_semi_cb, "system,%s",
                                           arg0, (int)arg1 + 1);
        } else {
            s = lock_user_string(arg0);
            if (!s) {
                errno = EFAULT;
                return set_swi_errno(cs, -1);
            }
            ret = set_swi_errno(cs, system(s));
            unlock_user(s, arg0, 0);
            return ret;
        }
    case TARGET_SYS_ERRNO:
        return get_swi_errno(cs);
    case TARGET_SYS_GET_CMDLINE:
        {
            /* Build a command-line from the original argv.
             *
             * The inputs are:
             *     * arg0, pointer to a buffer of at least the size
             *               specified in arg1.
             *     * arg1, size of the buffer pointed to by arg0 in
             *               bytes.
             *
             * The outputs are:
             *     * arg0, pointer to null-terminated string of the
             *               command line.
             *     * arg1, length of the string pointed to by arg0.
             */

            char *output_buffer;
            size_t input_size;
            size_t output_size;
            int status = 0;
#if !defined(CONFIG_USER_ONLY)
            const char *cmdline;
#else
            TaskState *ts = cs->opaque;
#endif
            GET_ARG(0);
            GET_ARG(1);
            input_size = arg1;
            /* Compute the size of the output string.  */
#if !defined(CONFIG_USER_ONLY)
            cmdline = semihosting_get_cmdline();
            if (cmdline == NULL) {
                cmdline = ""; /* Default to an empty line. */
            }
            output_size = strlen(cmdline) + 1; /* Count terminating 0. */
#else
            unsigned int i;

            output_size = ts->info->arg_end - ts->info->arg_start;
            if (!output_size) {
                /*
                 * We special-case the "empty command line" case (argc==0).
                 * Just provide the terminating 0.
                 */
                output_size = 1;
            }
#endif

            if (output_size > input_size) {
                /* Not enough space to store command-line arguments.  */
                errno = E2BIG;
                return set_swi_errno(cs, -1);
            }

            /* Adjust the command-line length.  */
            if (SET_ARG(1, output_size - 1)) {
                /* Couldn't write back to argument block */
                errno = EFAULT;
                return set_swi_errno(cs, -1);
            }

            /* Lock the buffer on the ARM side.  */
            output_buffer = lock_user(VERIFY_WRITE, arg0, output_size, 0);
            if (!output_buffer) {
                errno = EFAULT;
                return set_swi_errno(cs, -1);
            }

            /* Copy the command-line arguments.  */
#if !defined(CONFIG_USER_ONLY)
            pstrcpy(output_buffer, output_size, cmdline);
#else
            if (output_size == 1) {
                /* Empty command-line.  */
                output_buffer[0] = '\0';
                goto out;
            }

            if (copy_from_user(output_buffer, ts->info->arg_start,
                               output_size)) {
                errno = EFAULT;
                status = set_swi_errno(cs, -1);
                goto out;
            }

            /* Separate arguments by white spaces.  */
            for (i = 0; i < output_size - 1; i++) {
                if (output_buffer[i] == 0) {
                    output_buffer[i] = ' ';
                }
            }
        out:
#endif
            /* Unlock the buffer on the ARM side.  */
            unlock_user(output_buffer, arg0, output_size);

            return status;
        }
    case TARGET_SYS_HEAPINFO:
        {
            target_ulong retvals[4];
            target_ulong limit;
            int i;
#ifdef CONFIG_USER_ONLY
            TaskState *ts = cs->opaque;
#else
            target_ulong rambase = common_semi_rambase(cs);
#endif

            GET_ARG(0);

#ifdef CONFIG_USER_ONLY
            /*
             * Some C libraries assume the heap immediately follows .bss, so
             * allocate it using sbrk.
             */
            if (!ts->heap_limit) {
                abi_ulong ret;

                ts->heap_base = do_brk(0);
                limit = ts->heap_base + COMMON_SEMI_HEAP_SIZE;
                /* Try a big heap, and reduce the size if that fails.  */
                for (;;) {
                    ret = do_brk(limit);
                    if (ret >= limit) {
                        break;
                    }
                    limit = (ts->heap_base >> 1) + (limit >> 1);
                }
                ts->heap_limit = limit;
            }

            retvals[0] = ts->heap_base;
            retvals[1] = ts->heap_limit;
            retvals[2] = ts->stack_base;
            retvals[3] = 0; /* Stack limit.  */
#else
            limit = current_machine->ram_size;
            /* TODO: Make this use the limit of the loaded application.  */
            retvals[0] = rambase + limit / 2;
            retvals[1] = rambase + limit;
            retvals[2] = rambase + limit; /* Stack base */
            retvals[3] = rambase; /* Stack limit.  */
#endif

            for (i = 0; i < ARRAY_SIZE(retvals); i++) {
                bool fail;

                if (is_64bit_semihosting(env)) {
                    fail = put_user_u64(retvals[i], arg0 + i * 8);
                } else {
                    fail = put_user_u32(retvals[i], arg0 + i * 4);
                }

                if (fail) {
                    /* Couldn't write back to argument block */
                    errno = EFAULT;
                    return set_swi_errno(cs, -1);
                }
            }
            return 0;
        }
    case TARGET_SYS_EXIT:
    case TARGET_SYS_EXIT_EXTENDED:
        if (common_semi_sys_exit_extended(cs, nr)) {
            /*
             * The A64 version of SYS_EXIT takes a parameter block,
             * so the application-exit type can return a subcode which
             * is the exit status code from the application.
             * SYS_EXIT_EXTENDED is an a new-in-v2.0 optional function
             * which allows A32/T32 guests to also provide a status code.
             */
            GET_ARG(0);
            GET_ARG(1);

            if (arg0 == ADP_Stopped_ApplicationExit) {
                ret = arg1;
            } else {
                ret = 1;
            }
        } else {
            /*
             * The A32/T32 version of SYS_EXIT specifies only
             * Stopped_ApplicationExit as normal exit, but does not
             * allow the guest to specify the exit status code.
             * Everything else is considered an error.
             */
            ret = (args == ADP_Stopped_ApplicationExit) ? 0 : 1;
        }
        gdb_exit(ret);
        exit(ret);
    case TARGET_SYS_ELAPSED:
        elapsed = get_clock() - clock_start;
        if (sizeof(target_ulong) == 8) {
            SET_ARG(0, elapsed);
        } else {
            SET_ARG(0, (uint32_t) elapsed);
            SET_ARG(1, (uint32_t) (elapsed >> 32));
        }
        return 0;
    case TARGET_SYS_TICKFREQ:
        /* qemu always uses nsec */
        return 1000000000;
    case TARGET_SYS_SYNCCACHE:
        /*
         * Clean the D-cache and invalidate the I-cache for the specified
         * virtual address range. This is a nop for us since we don't
         * implement caches. This is only present on A64.
         */
#ifdef TARGET_ARM
        if (is_a64(cs->env_ptr)) {
            return 0;
        }
#endif
#ifdef TARGET_RISCV
        return 0;
#endif
        /* fall through -- invalid for A32/T32 */
    default:
        fprintf(stderr, "qemu: Unsupported SemiHosting SWI 0x%02x\n", nr);
        cpu_dump_state(cs, stderr, 0);
        abort();
    }
}