Date: Tue, 24 Sep 2013 12:24:48 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r255844 - head/sys/amd64/amd64 Message-ID: <201309241224.r8OCOmxB063332@svn.freebsd.org>
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Author: kib Date: Tue Sep 24 12:24:48 2013 New Revision: 255844 URL: http://svnweb.freebsd.org/changeset/base/255844 Log: Ensure that the ERESTART return from the syscall reloads the registers, to make the restarted syscall instruction pass the correct arguments. PR: kern/182161 Reported by: Russ Cox <rsc@swtch.com> Sponsored by: The FreeBSD Foundation MFC after: 3 days Approved by: re (marius) Modified: head/sys/amd64/amd64/vm_machdep.c Modified: head/sys/amd64/amd64/vm_machdep.c ============================================================================== --- head/sys/amd64/amd64/vm_machdep.c Tue Sep 24 11:49:04 2013 (r255843) +++ head/sys/amd64/amd64/vm_machdep.c Tue Sep 24 12:24:48 2013 (r255844) @@ -400,9 +400,13 @@ cpu_set_syscall_retval(struct thread *td * for the next iteration. * %r10 restore is only required for freebsd/amd64 processes, * but shall be innocent for any ia32 ABI. + * + * Require full context restore to get the arguments + * in the registers reloaded at return to usermode. */ td->td_frame->tf_rip -= td->td_frame->tf_err; td->td_frame->tf_r10 = td->td_frame->tf_rcx; + set_pcb_flags(td->td_pcb, PCB_FULL_IRET); break; case EJUSTRETURN:
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