Author: kib Date: Fri Sep 18 16:52:18 2015 New Revision: 287960 URL: https://svnweb.freebsd.org/changeset/base/287960
Log: Clear exclusive monitors when handling data aborts, the monitors are in unknown state per spec. Reviewed by: andrew (previous version) Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D3668 Modified: head/sys/arm64/arm64/trap.c head/sys/arm64/include/cpufunc.h Modified: head/sys/arm64/arm64/trap.c ============================================================================== --- head/sys/arm64/arm64/trap.c Fri Sep 18 13:44:15 2015 (r287959) +++ head/sys/arm64/arm64/trap.c Fri Sep 18 16:52:18 2015 (r287960) @@ -155,6 +155,13 @@ data_abort(struct trapframe *frame, uint uint64_t far; int error, sig, ucode; + /* + * According to the ARMv8-A rev. A.g, B2.10.5 "Load-Exclusive + * and Store-Exclusive instruction usage restrictions", state + * of the exclusive monitors after data abort exception is unknown. + */ + clrex(); + #ifdef KDB if (kdb_active) { kdb_reenter(); Modified: head/sys/arm64/include/cpufunc.h ============================================================================== --- head/sys/arm64/include/cpufunc.h Fri Sep 18 13:44:15 2015 (r287959) +++ head/sys/arm64/include/cpufunc.h Fri Sep 18 16:52:18 2015 (r287960) @@ -108,6 +108,17 @@ get_mpidr(void) return (mpidr); } +static __inline void +clrex(void) +{ + + /* + * Ensure compiler barrier, otherwise the monitor clear might + * occur too late for us ? + */ + __asm __volatile("clrex" : : : "memory"); +} + #define cpu_nullop() arm64_nullop() #define cpufunc_nullop() arm64_nullop() #define cpu_setttb(a) arm64_setttb(a) _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
