Date: Sat, 30 Oct 2010 23:07:30 +0000 (UTC) From: Nathan Whitehorn <nwhitehorn@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/sys/powerpc/aim copyinout.c slb.c swtch64.S trap.c trap_subr32.S trap_subr64.S vm_machdep.c src/sys/powerpc/include pcb.h slb.h sr.h src/sys/powerpc/powerpc exec_machdep.c genassym.c Message-ID: <201010302307.o9UN7mF3034137@repoman.freebsd.org>
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nwhitehorn 2010-10-30 23:07:30 UTC
FreeBSD src repository
Modified files:
sys/powerpc/aim copyinout.c slb.c swtch64.S trap.c
trap_subr32.S trap_subr64.S vm_machdep.c
sys/powerpc/include pcb.h slb.h sr.h
sys/powerpc/powerpc exec_machdep.c genassym.c
Log:
SVN rev 214574 on 2010-10-30 23:07:30Z by nwhitehorn
Restructure the way the copyin/copyout segment is stored to prevent a
concurrency bug. Since all SLB/SR entries were invalidated during an
exception, a decrementer exception could cause the user segment to be
invalidated during a copyin()/copyout() without a thread switch that
would cause it to be restored from the PCB, potentially causing the
operation to continue on invalid memory. This is now handled by explicit
restoration of segment 12 from the PCB on 32-bit systems and a check in
the Data Segment Exception handler on 64-bit.
While here, cause copyin()/copyout() to check whether the requested
user segment is already installed, saving some pipeline flushes, and
fix the synchronization primitives around the mtsr and slbmte
instructions to prevent accessing stale segments.
MFC after: 2 weeks
Revision Changes Path
1.20 +16 -13 src/sys/powerpc/aim/copyinout.c
1.5 +7 -7 src/sys/powerpc/aim/slb.c
1.2 +8 -8 src/sys/powerpc/aim/swtch64.S
1.87 +9 -1 src/sys/powerpc/aim/trap.c
1.2 +9 -2 src/sys/powerpc/aim/trap_subr32.S
1.3 +1 -1 src/sys/powerpc/aim/trap_subr64.S
1.130 +0 -1 src/sys/powerpc/aim/vm_machdep.c
1.16 +0 -1 src/sys/powerpc/include/pcb.h
1.3 +7 -0 src/sys/powerpc/include/slb.h
1.9 +0 -4 src/sys/powerpc/include/sr.h
1.4 +0 -1 src/sys/powerpc/powerpc/exec_machdep.c
1.68 +3 -2 src/sys/powerpc/powerpc/genassym.c
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