Commit f01a361b authored Jun 29, 2015 by Andrew Bennett Committed by Leon Alrae Jul 15, 2015

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>

parent 26e7e982

linux-user/main.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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) {