From 0284b03ba3f47da53b6b46293a3d586c08829f7e Mon Sep 17 00:00:00 2001 From: Timothy E Baldwin Date: Thu, 12 May 2016 18:47:30 +0100 Subject: linux-user: Support for restarting system calls for x86 targets Update the x86 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 rather than passing it back out as the "return code" from do_sigreturn() * handle TARGET_QEMU_ESIGRETURN in the main loop as the indication that the main loop should not touch EAX Signed-off-by: Timothy Edward Baldwin Message-id: 1441497448-32489-5-git-send-email-T.E.Baldwin99@members.leeds.ac.uk Reviewed-by: Peter Maydell [PMM: Commit message tweaks; drop TARGET_USE_ERESTARTSYS define] Signed-off-by: Peter Maydell Signed-off-by: Riku Voipio --- linux-user/main.c | 47 +++++++++++++++++++++++++++++------------------ 1 file changed, 29 insertions(+), 18 deletions(-) (limited to 'linux-user/main.c') diff --git a/linux-user/main.c b/linux-user/main.c index 95ed11d85c..da5a0333b6 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -285,6 +285,7 @@ void cpu_loop(CPUX86State *env) CPUState *cs = CPU(x86_env_get_cpu(env)); int trapnr; abi_ulong pc; + abi_ulong ret; target_siginfo_t info; for(;;) { @@ -294,28 +295,38 @@ void cpu_loop(CPUX86State *env) switch(trapnr) { case 0x80: /* linux syscall from int $0x80 */ - env->regs[R_EAX] = do_syscall(env, - env->regs[R_EAX], - env->regs[R_EBX], - env->regs[R_ECX], - env->regs[R_EDX], - env->regs[R_ESI], - env->regs[R_EDI], - env->regs[R_EBP], - 0, 0); + ret = do_syscall(env, + env->regs[R_EAX], + env->regs[R_EBX], + env->regs[R_ECX], + env->regs[R_EDX], + env->regs[R_ESI], + env->regs[R_EDI], + env->regs[R_EBP], + 0, 0); + if (ret == -TARGET_ERESTARTSYS) { + env->eip -= 2; + } else if (ret != -TARGET_QEMU_ESIGRETURN) { + env->regs[R_EAX] = ret; + } break; #ifndef TARGET_ABI32 case EXCP_SYSCALL: /* linux syscall from syscall instruction */ - env->regs[R_EAX] = do_syscall(env, - env->regs[R_EAX], - env->regs[R_EDI], - env->regs[R_ESI], - env->regs[R_EDX], - env->regs[10], - env->regs[8], - env->regs[9], - 0, 0); + ret = do_syscall(env, + env->regs[R_EAX], + env->regs[R_EDI], + env->regs[R_ESI], + env->regs[R_EDX], + env->regs[10], + env->regs[8], + env->regs[9], + 0, 0); + if (ret == -TARGET_ERESTARTSYS) { + env->eip -= 2; + } else if (ret != -TARGET_QEMU_ESIGRETURN) { + env->regs[R_EAX] = ret; + } break; #endif case EXCP0B_NOSEG: -- cgit 1.4.1