From 00bb01a40c811f9645a4b4a956a94e76b0ba5d43 Mon Sep 17 00:00:00 2001 From: "George V. Neville-Neil" Date: Fri, 3 Feb 2017 22:26:19 +0000 Subject: [PATCH] Replace the implementation of DTrace's RAND subroutine for generating low-quality random numbers with a modern implementation (xoroshiro128+) that is capable of generating better quality randomness without compromising performance. Submitted by: Graeme Jenkinson Reviewed by: markj MFC after: 2 weeks Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D9051 --- .../opensolaris/uts/common/dtrace/dtrace.c | 23 +++++++++++++++++-- .../opensolaris/uts/common/sys/dtrace_impl.h | 6 +++++ sys/modules/dtrace/dtrace/Makefile | 2 ++ sys/modules/dtrace/fasttrap/Makefile | 1 + sys/modules/dtrace/systrace/Makefile | 1 + 5 files changed, 31 insertions(+), 2 deletions(-) diff --git a/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c b/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c index 7c97c2db056..1e3d21491b3 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c +++ b/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c @@ -124,6 +124,7 @@ #include #include #include +#include #include #include #include @@ -136,6 +137,8 @@ #include "dtrace_debug.c" #endif +#include "dtrace_xoroshiro128_plus.h" + /* * DTrace Tunable Variables * @@ -298,7 +301,6 @@ static kmutex_t dtrace_meta_lock; /* meta-provider state lock */ #define vuprintf vprintf #define ttoproc(_a) ((_a)->td_proc) #define crgetzoneid(_a) 0 -#define NCPU MAXCPU #define SNOCD 0 #define CPU_ON_INTR(_a) 0 @@ -4236,7 +4238,8 @@ dtrace_dif_subr(uint_t subr, uint_t rd, uint64_t *regs, switch (subr) { case DIF_SUBR_RAND: - regs[rd] = (dtrace_gethrtime() * 2416 + 374441) % 1771875; + regs[rd] = dtrace_xoroshiro128_plus_next( + state->dts_rstate[curcpu]); break; #ifdef illumos @@ -14495,6 +14498,7 @@ dtrace_state_create(struct cdev *dev, struct ucred *cred __unused) dtrace_state_t *state; dtrace_optval_t *opt; int bufsize = NCPU * sizeof (dtrace_buffer_t), i; + int cpu_it; ASSERT(MUTEX_HELD(&dtrace_lock)); ASSERT(MUTEX_HELD(&cpu_lock)); @@ -14550,6 +14554,21 @@ dtrace_state_create(struct cdev *dev, struct ucred *cred __unused) state->dts_buffer = kmem_zalloc(bufsize, KM_SLEEP); state->dts_aggbuffer = kmem_zalloc(bufsize, KM_SLEEP); + /* + * Allocate and initialise the per-process per-CPU random state. + * SI_SUB_RANDOM < SI_SUB_DTRACE_ANON therefore entropy device is + * assumed to be seeded at this point (if from Fortuna seed file). + */ + (void) read_random(&state->dts_rstate[0], 2 * sizeof(uint64_t)); + for (cpu_it = 1; cpu_it < NCPU; cpu_it++) { + /* + * Each CPU is assigned a 2^64 period, non-overlapping + * subsequence. + */ + dtrace_xoroshiro128_plus_jump(state->dts_rstate[cpu_it-1], + state->dts_rstate[cpu_it]); + } + #ifdef illumos state->dts_cleaner = CYCLIC_NONE; state->dts_deadman = CYCLIC_NONE; diff --git a/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace_impl.h b/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace_impl.h index 130511de037..0b8df9834fa 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace_impl.h +++ b/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace_impl.h @@ -50,6 +50,7 @@ extern "C" { */ #include + #ifndef illumos #ifdef __sparcv9 typedef uint32_t pc_t; @@ -65,6 +66,10 @@ typedef u_long greg_t; #define DTRACE_MAXPROPLEN 128 #define DTRACE_DYNVAR_CHUNKSIZE 256 +#ifdef __FreeBSD__ +#define NCPU MAXCPU +#endif /* __FreeBSD__ */ + struct dtrace_probe; struct dtrace_ecb; struct dtrace_predicate; @@ -1169,6 +1174,7 @@ struct dtrace_state { dtrace_cred_t dts_cred; /* credentials */ size_t dts_nretained; /* number of retained enabs */ int dts_getf; /* number of getf() calls */ + uint64_t dts_rstate[NCPU][2]; /* per-CPU random state */ }; struct dtrace_provider { diff --git a/sys/modules/dtrace/dtrace/Makefile b/sys/modules/dtrace/dtrace/Makefile index 0889646f88c..35287d12730 100644 --- a/sys/modules/dtrace/dtrace/Makefile +++ b/sys/modules/dtrace/dtrace/Makefile @@ -12,6 +12,7 @@ ARCHDIR= ${MACHINE_CPUARCH} KMOD= dtrace SRCS= dtrace.c \ + dtrace_xoroshiro128_plus.c \ dtrace_asm.S \ dtrace_subr.c @@ -42,6 +43,7 @@ CFLAGS+= -I${SYSDIR}/cddl/compat/opensolaris \ -I${SYSDIR}/cddl/dev/dtrace \ -I${SYSDIR}/cddl/dev/dtrace/${ARCHDIR} \ -I${SYSDIR}/cddl/contrib/opensolaris/uts/common \ + -I${SYSDIR}/cddl/contrib/opensolaris/uts/common/dtrace \ -I${SYSDIR}/cddl/contrib/opensolaris/common/util \ -I${SYSDIR} -DDIS_MEM diff --git a/sys/modules/dtrace/fasttrap/Makefile b/sys/modules/dtrace/fasttrap/Makefile index 260e4953e3c..be65a3d1d8f 100644 --- a/sys/modules/dtrace/fasttrap/Makefile +++ b/sys/modules/dtrace/fasttrap/Makefile @@ -10,6 +10,7 @@ SRCS+= vnode_if.h CFLAGS+= -I${SYSDIR}/cddl/compat/opensolaris \ -I${SYSDIR}/cddl/contrib/opensolaris/uts/common \ + -I${SYSDIR}/cddl/contrib/opensolaris/uts/common/dtrace \ -I${SYSDIR} .if ${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386" diff --git a/sys/modules/dtrace/systrace/Makefile b/sys/modules/dtrace/systrace/Makefile index 88daa0bf6f4..1d6f1875b3f 100644 --- a/sys/modules/dtrace/systrace/Makefile +++ b/sys/modules/dtrace/systrace/Makefile @@ -10,6 +10,7 @@ SRCS+= vnode_if.h CFLAGS+= -I${SYSDIR}/cddl/compat/opensolaris \ -I${SYSDIR}/cddl/contrib/opensolaris/uts/common \ + -I${SYSDIR}/cddl/contrib/opensolaris/uts/common/dtrace \ -I${SYSDIR} .include