Date: Fri, 27 Sep 2013 07:02:48 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org Subject: svn commit: r255906 - stable/8/sys/amd64/amd64 Message-ID: <201309270702.r8R72mvg093497@svn.freebsd.org>
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Author: kib Date: Fri Sep 27 07:02:48 2013 New Revision: 255906 URL: http://svnweb.freebsd.org/changeset/base/255906 Log: MFC r255844: Ensure that the ERESTART return from the syscall reloads the registers, to make the restarted syscall instruction pass the correct arguments. PR: kern/182161 Modified: stable/8/sys/amd64/amd64/vm_machdep.c Directory Properties: stable/8/sys/ (props changed) stable/8/sys/amd64/ (props changed) Modified: stable/8/sys/amd64/amd64/vm_machdep.c ============================================================================== --- stable/8/sys/amd64/amd64/vm_machdep.c Fri Sep 27 06:56:58 2013 (r255905) +++ stable/8/sys/amd64/amd64/vm_machdep.c Fri Sep 27 07:02:48 2013 (r255906) @@ -395,9 +395,13 @@ 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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