From ec860426dfbebe0c9995e12cd82935a94fde5215 Mon Sep 17 00:00:00 2001 From: Alex Richardson Date: Sun, 2 Feb 2020 15:34:09 +0000 Subject: [PATCH] target/mips: Fix handling of LL/SC instructions after 7dd547e5ab MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit After 7dd547e5ab6b31e7a0cfc182d3ad131dd55a948f the env->llval value is loaded as an unsigned value (instead of sign-extended as before). Therefore, the CMPXCHG in gen_st_cond() in translate.c fails if the sign bit is set in the loaded value. Fix this by sign-extending the llval value for the 32-bit case. I discovered this issue because FreeBSD MIPS64 was looping forever in an atomic helper function when trying to start /sbin/init. Signed-off-by: Alex Richardson Fixes: 7dd547e5ab ("target/mips: Use cpu_*_mmuidx_ra instead of MMU_MODE*_SUFFIX") Buglink: https://bugs.launchpad.net/qemu/+bug/1861605 Cc: Aurelien Jarno Cc: Aleksandar Markovic Cc: Aleksandar Rikalo Cc: Richard Henderson Signed-off-by: James Clarke Signed-off-by: Aleksandar Markovic Reviewed-by: Richard Henderson Tested-by: Philippe Mathieu-Daudé Message-Id: <20200202153409.28534-1-jrtc27@jrtc27.com> --- target/mips/op_helper.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/target/mips/op_helper.c b/target/mips/op_helper.c index 15d05a5fbc..467914d1ca 100644 --- a/target/mips/op_helper.c +++ b/target/mips/op_helper.c @@ -305,7 +305,7 @@ static inline hwaddr do_translate_address(CPUMIPSState *env, } } -#define HELPER_LD_ATOMIC(name, insn, almask) \ +#define HELPER_LD_ATOMIC(name, insn, almask, do_cast) \ target_ulong helper_##name(CPUMIPSState *env, target_ulong arg, int mem_idx) \ { \ if (arg & almask) { \ @@ -316,12 +316,12 @@ target_ulong helper_##name(CPUMIPSState *env, target_ulong arg, int mem_idx) \ } \ env->CP0_LLAddr = do_translate_address(env, arg, 0, GETPC()); \ env->lladdr = arg; \ - env->llval = cpu_##insn##_mmuidx_ra(env, arg, mem_idx, GETPC()); \ + env->llval = do_cast cpu_##insn##_mmuidx_ra(env, arg, mem_idx, GETPC()); \ return env->llval; \ } -HELPER_LD_ATOMIC(ll, ldl, 0x3) +HELPER_LD_ATOMIC(ll, ldl, 0x3, (target_long)(int32_t)) #ifdef TARGET_MIPS64 -HELPER_LD_ATOMIC(lld, ldq, 0x7) +HELPER_LD_ATOMIC(lld, ldq, 0x7, (target_ulong)) #endif #undef HELPER_LD_ATOMIC #endif -- GitLab