Fix commandline handling for ARM semihosted executables
Use the copy of the command line that loader_build_argptr() sets up in guest memory as the command line to return from the ARM SYS_GET_CMDLINE semihosting call. Previously we were using a pointer to memory which had already been freed before the guest program started. This fixes https://bugs.launchpad.net/qemu/+bug/673613 . Signed-off-by: Wolfgang Schildbach <wschi@dolby.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
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								arm-semi.c
									
									
									
									
									
								
							@ -373,45 +373,64 @@ uint32_t do_arm_semihosting(CPUState *env)
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#ifdef CONFIG_USER_ONLY
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					#ifdef CONFIG_USER_ONLY
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        /* Build a commandline from the original argv.  */
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					        /* Build a commandline from the original argv.  */
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        {
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					        {
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            char **arg = ts->info->host_argv;
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					            char *arm_cmdline_buffer;
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            int len = ARG(1);
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					            const char *host_cmdline_buffer;
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            /* lock the buffer on the ARM side */
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            char *cmdline_buffer = (char*)lock_user(VERIFY_WRITE, ARG(0), len, 0);
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            if (!cmdline_buffer)
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					            unsigned int i;
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                /* FIXME - should this error code be -TARGET_EFAULT ? */
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					            unsigned int arm_cmdline_len = ARG(1);
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                return (uint32_t)-1;
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					            unsigned int host_cmdline_len =
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					                ts->info->arg_end-ts->info->arg_start;
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            s = cmdline_buffer;
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					            if (!arm_cmdline_len || host_cmdline_len > arm_cmdline_len) {
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            while (*arg && len > 2) {
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					                return -1; /* not enough space to store command line */
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                int n = strlen(*arg);
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                if (s != cmdline_buffer) {
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                    *(s++) = ' ';
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                    len--;
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                }
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                if (n >= len)
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                    n = len - 1;
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                memcpy(s, *arg, n);
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                s += n;
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                len -= n;
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                arg++;
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            }
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					            }
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            /* Null terminate the string.  */
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            *s = 0;
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            len = s - cmdline_buffer;
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            /* Unlock the buffer on the ARM side.  */
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					            if (!host_cmdline_len) {
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            unlock_user(cmdline_buffer, ARG(0), len);
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					                /* We special-case the "empty command line" case (argc==0).
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					                   Just provide the terminating 0. */
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					                arm_cmdline_buffer = lock_user(VERIFY_WRITE, ARG(0), 1, 0);
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					                arm_cmdline_buffer[0] = 0;
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					                unlock_user(arm_cmdline_buffer, ARG(0), 1);
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            /* Adjust the commandline length argument.  */
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					                /* Adjust the commandline length argument. */
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            SET_ARG(1, len);
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					                SET_ARG(1, 0);
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					                return 0;
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					            }
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            /* Return success if commandline fit into buffer.  */
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					            /* lock the buffers on the ARM side */
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            return *arg ? -1 : 0;
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					            arm_cmdline_buffer =
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					                lock_user(VERIFY_WRITE, ARG(0), host_cmdline_len, 0);
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					            host_cmdline_buffer =
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					                lock_user(VERIFY_READ, ts->info->arg_start,
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					                                       host_cmdline_len, 1);
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					            if (arm_cmdline_buffer && host_cmdline_buffer)
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					            {
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					                /* the last argument is zero-terminated;
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					                   no need for additional termination */
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					                memcpy(arm_cmdline_buffer, host_cmdline_buffer,
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					                       host_cmdline_len);
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					                /* separate arguments by white spaces */
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					                for (i = 0; i < host_cmdline_len-1; i++) {
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					                    if (arm_cmdline_buffer[i] == 0) {
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					                        arm_cmdline_buffer[i] = ' ';
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					                    }
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					                }
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					                /* Adjust the commandline length argument. */
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					                SET_ARG(1, host_cmdline_len-1);
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					            }
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					            /* Unlock the buffers on the ARM side.  */
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					            unlock_user(arm_cmdline_buffer, ARG(0), host_cmdline_len);
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					            unlock_user((void*)host_cmdline_buffer, ts->info->arg_start, 0);
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					            /* Return success if we could return a commandline.  */
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					            return (arm_cmdline_buffer && host_cmdline_buffer) ? 0 : -1;
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        }
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					        }
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#else
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					#else
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      return -1;
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					        return -1;
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#endif
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					#endif
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    case SYS_HEAPINFO:
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					    case SYS_HEAPINFO:
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        {
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					        {
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