linux-user: Verify MIPS syscall arguments

On MIPS, some syscall arguments are taken from the stack. This patch adds
verification such that do_syscall() is only invoked if all arguments
have been successfully taken from the stack.

Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: An-Cheng Huang <ancheng@ubnt.com>
This commit is contained in:
An-Cheng Huang 2011-08-09 12:32:38 -07:00 committed by Riku Voipio
parent 29fb0f2530
commit 94c19610a6

View File

@ -2170,11 +2170,22 @@ void cpu_loop(CPUMIPSState *env)
sp_reg = env->active_tc.gpr[29];
switch (nb_args) {
/* these arguments are taken from the stack */
/* FIXME - what to do if get_user() fails? */
case 8: get_user_ual(arg8, sp_reg + 28);
case 7: get_user_ual(arg7, sp_reg + 24);
case 6: get_user_ual(arg6, sp_reg + 20);
case 5: get_user_ual(arg5, sp_reg + 16);
case 8:
if ((ret = get_user_ual(arg8, sp_reg + 28)) != 0) {
goto done_syscall;
}
case 7:
if ((ret = get_user_ual(arg7, sp_reg + 24)) != 0) {
goto done_syscall;
}
case 6:
if ((ret = get_user_ual(arg6, sp_reg + 20)) != 0) {
goto done_syscall;
}
case 5:
if ((ret = get_user_ual(arg5, sp_reg + 16)) != 0) {
goto done_syscall;
}
default:
break;
}
@ -2185,6 +2196,7 @@ void cpu_loop(CPUMIPSState *env)
env->active_tc.gpr[7],
arg5, arg6, arg7, arg8);
}
done_syscall:
if (ret == -TARGET_QEMU_ESIGRETURN) {
/* Returning from a successful sigreturn syscall.
Avoid clobbering register state. */