From f0267ef7115656119bf00ed77857789adc036bda Mon Sep 17 00:00:00 2001 From: Timothy E Baldwin Date: Thu, 12 May 2016 18:47:31 +0100 Subject: [PATCH] linux-user: Support for restarting system calls for ARM targets Update the 32-bit and 64-bit ARM main loop and sigreturn code: * on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn * set all guest CPU state within signal.c code on sigreturn * handle TARGET_QEMU_ESIGRETURN in the main loop as the indication that the main loop should not touch any guest CPU state Signed-off-by: Timothy Edward Baldwin Message-id: 1441497448-32489-6-git-send-email-T.E.Baldwin99@members.leeds.ac.uk Reviewed-by: Peter Maydell [PMM: tweak commit message; drop TARGET_USE_ERESTARTSYS define] Signed-off-by: Peter Maydell Signed-off-by: Riku Voipio --- linux-user/arm/target_signal.h | 1 + linux-user/main.c | 48 ++++++++++++++++++++++++++---------------- linux-user/signal.c | 10 ++++----- 3 files changed, 36 insertions(+), 23 deletions(-) diff --git a/linux-user/arm/target_signal.h b/linux-user/arm/target_signal.h index 2b3281312b..fb31f4c5ec 100644 --- a/linux-user/arm/target_signal.h +++ b/linux-user/arm/target_signal.h @@ -26,4 +26,5 @@ static inline abi_ulong get_sp_from_cpustate(CPUARMState *state) return state->regs[13]; } + #endif /* TARGET_SIGNAL_H */ diff --git a/linux-user/main.c b/linux-user/main.c index da5a0333b6..7916efc0e2 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -727,6 +727,7 @@ void cpu_loop(CPUARMState *env) unsigned int n, insn; target_siginfo_t info; uint32_t addr; + abi_ulong ret; for(;;) { cpu_exec_start(cs); @@ -865,15 +866,20 @@ void cpu_loop(CPUARMState *env) break; } } else { - env->regs[0] = do_syscall(env, - n, - env->regs[0], - env->regs[1], - env->regs[2], - env->regs[3], - env->regs[4], - env->regs[5], - 0, 0); + ret = do_syscall(env, + n, + env->regs[0], + env->regs[1], + env->regs[2], + env->regs[3], + env->regs[4], + env->regs[5], + 0, 0); + if (ret == -TARGET_ERESTARTSYS) { + env->regs[15] -= env->thumb ? 2 : 4; + } else if (ret != -TARGET_QEMU_ESIGRETURN) { + env->regs[0] = ret; + } } } else { goto error; @@ -1056,6 +1062,7 @@ void cpu_loop(CPUARMState *env) { CPUState *cs = CPU(arm_env_get_cpu(env)); int trapnr, sig; + abi_long ret; target_siginfo_t info; for (;;) { @@ -1065,15 +1072,20 @@ void cpu_loop(CPUARMState *env) switch (trapnr) { case EXCP_SWI: - env->xregs[0] = do_syscall(env, - env->xregs[8], - env->xregs[0], - env->xregs[1], - env->xregs[2], - env->xregs[3], - env->xregs[4], - env->xregs[5], - 0, 0); + ret = do_syscall(env, + env->xregs[8], + env->xregs[0], + env->xregs[1], + env->xregs[2], + env->xregs[3], + env->xregs[4], + env->xregs[5], + 0, 0); + if (ret == -TARGET_ERESTARTSYS) { + env->pc -= 4; + } else if (ret != -TARGET_QEMU_ESIGRETURN) { + env->xregs[0] = ret; + } break; case EXCP_INTERRUPT: /* just indicate that signals should be handled asap */ diff --git a/linux-user/signal.c b/linux-user/signal.c index 11ddd05173..14e58b05b2 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -1390,7 +1390,7 @@ long do_rt_sigreturn(CPUARMState *env) } unlock_user_struct(frame, frame_addr, 0); - return env->xregs[0]; + return -TARGET_QEMU_ESIGRETURN; badframe: unlock_user_struct(frame, frame_addr, 0); @@ -1902,7 +1902,7 @@ static long do_sigreturn_v1(CPUARMState *env) send_sig(SIGTRAP, current, 1); #endif unlock_user_struct(frame, frame_addr, 0); - return env->regs[0]; + return -TARGET_QEMU_ESIGRETURN; badframe: force_sig(TARGET_SIGSEGV /* , current */); @@ -2028,7 +2028,7 @@ static long do_sigreturn_v2(CPUARMState *env) } unlock_user_struct(frame, frame_addr, 0); - return env->regs[0]; + return -TARGET_QEMU_ESIGRETURN; badframe: unlock_user_struct(frame, frame_addr, 0); @@ -2082,7 +2082,7 @@ static long do_rt_sigreturn_v1(CPUARMState *env) send_sig(SIGTRAP, current, 1); #endif unlock_user_struct(frame, frame_addr, 0); - return env->regs[0]; + return -TARGET_QEMU_ESIGRETURN; badframe: unlock_user_struct(frame, frame_addr, 0); @@ -2115,7 +2115,7 @@ static long do_rt_sigreturn_v2(CPUARMState *env) } unlock_user_struct(frame, frame_addr, 0); - return env->regs[0]; + return -TARGET_QEMU_ESIGRETURN; badframe: unlock_user_struct(frame, frame_addr, 0); -- 2.11.4.GIT