linux-user: Fix MIPS N64 trap and break instruction bug

For the MIPS N64 ABI when QEMU reads the break/trap instruction so that
it can inspect the break/trap code it reads 8 rather than 4 bytes
which means it finds the code field from the instruction after the
break/trap instruction.  This then causes the break/trap handling
code to fail because it does not understand the code number.

The fix forces QEMU to always read 4 bytes of instruction data rather
than deciding how much to read based on the ABI.

Signed-off-by: Andrew Bennett <andrew.bennett@imgtec.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
This commit is contained in:
Andrew Bennett 2015-06-29 10:20:07 +00:00 committed by Leon Alrae
parent 26e7e982b2
commit f01a361bfc

View File

@ -2577,7 +2577,7 @@ done_syscall:
code = (trap_instr >> 6) & 0x3f;
}
} else {
ret = get_user_ual(trap_instr, env->active_tc.PC);
ret = get_user_u32(trap_instr, env->active_tc.PC);
if (ret != 0) {
goto error;
}
@ -2611,7 +2611,7 @@ done_syscall:
trap_instr = (instr[0] << 16) | instr[1];
} else {
ret = get_user_ual(trap_instr, env->active_tc.PC);
ret = get_user_u32(trap_instr, env->active_tc.PC);
}
if (ret != 0) {