From 1308c464a8414ce3c6f79e172255fb90b5aa313d Mon Sep 17 00:00:00 2001 From: Kwok Cheung Yeung Date: Mon, 9 Sep 2013 17:36:40 -0700 Subject: linux-user: Check type of microMIPS break instruction microMIPS instructions that cause breakpoint exceptions come in 16-bit and 32-bit variants. When handling exceptions caused by such instructions, the instruction type needs to be taken into account when extracting the break code. The code has also been restructured for better clarity. Signed-off-by: Kwok Cheung Yeung Signed-off-by: Riku Voipio --- linux-user/main.c | 56 ++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 35 insertions(+), 21 deletions(-) (limited to 'linux-user') diff --git a/linux-user/main.c b/linux-user/main.c index 016e2e1755..1561950bf5 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -2400,12 +2400,31 @@ done_syscall: if (env->hflags & MIPS_HFLAG_M16) { if (env->insn_flags & ASE_MICROMIPS) { /* microMIPS mode */ - abi_ulong instr[2]; - - ret = get_user_u16(instr[0], env->active_tc.PC) || - get_user_u16(instr[1], env->active_tc.PC + 2); + ret = get_user_u16(trap_instr, env->active_tc.PC); + if (ret != 0) { + goto error; + } - trap_instr = (instr[0] << 16) | instr[1]; + if ((trap_instr >> 10) == 0x11) { + /* 16-bit instruction */ + code = trap_instr & 0xf; + } else { + /* 32-bit instruction */ + abi_ulong instr_lo; + + ret = get_user_u16(instr_lo, + env->active_tc.PC + 2); + if (ret != 0) { + goto error; + } + trap_instr = (trap_instr << 16) | instr_lo; + code = ((trap_instr >> 6) & ((1 << 20) - 1)); + /* Unfortunately, microMIPS also suffers from + the old assembler bug... */ + if (code >= (1 << 10)) { + code >>= 10; + } + } } else { /* MIPS16e mode */ ret = get_user_u16(trap_instr, env->active_tc.PC); @@ -2413,26 +2432,21 @@ done_syscall: goto error; } code = (trap_instr >> 6) & 0x3f; - if (do_break(env, &info, code) != 0) { - goto error; - } - break; } } else { ret = get_user_ual(trap_instr, env->active_tc.PC); - } - - if (ret != 0) { - goto error; - } + if (ret != 0) { + goto error; + } - /* As described in the original Linux kernel code, the - * below checks on 'code' are to work around an old - * assembly bug. - */ - code = ((trap_instr >> 6) & ((1 << 20) - 1)); - if (code >= (1 << 10)) { - code >>= 10; + /* As described in the original Linux kernel code, the + * below checks on 'code' are to work around an old + * assembly bug. + */ + code = ((trap_instr >> 6) & ((1 << 20) - 1)); + if (code >= (1 << 10)) { + code >>= 10; + } } if (do_break(env, &info, code) != 0) { -- cgit v1.2.1