adding dtracy (crude early version)

1 files changed, 286 insertions, 0 deletions

diff --git a/sys/src/libdtracy/prog.c b/sys/src/libdtracy/prog.c
new file mode 100644
index 000000000..7aced0815
--- /dev/null
+++ b/sys/src/libdtracy/prog.c
@@ -0,0 +1,286 @@
+#include <u.h>
+#include <libc.h>
+#include <dtracy.h>
+
+int
+dteverify(DTExpr *p)
+{
+	int i, nregs;
+	u32int ins;
+	u8int a, b, c;
+	
+	nregs = 16;
+	for(i = 0; i < p->n; i++){
+		ins = p->b[i];
+		
+		a = ins >> 16;
+		b = ins >> 8;
+		c = ins;
+		switch(ins>>24){
+		case DTE_ADD:
+			if(ins == 0) continue;
+			/* wet floor */
+		case DTE_SUB:
+		case DTE_MUL:
+		case DTE_UDIV:
+		case DTE_UMOD:
+		case DTE_SDIV:
+		case DTE_SMOD:
+		case DTE_AND:
+		case DTE_OR:
+		case DTE_XOR:
+		case DTE_XNOR:
+		case DTE_LSL:
+		case DTE_LSR:
+		case DTE_ASR:
+		case DTE_SEQ:
+		case DTE_SNE:
+		case DTE_SLT:
+		case DTE_SLE:
+			if(a >= nregs || b >= nregs || c >= nregs || c == 0)
+				goto invalid;
+			break;
+		case DTE_LDI:
+		case DTE_XORI:
+			if(c >= nregs || c == 0)
+				goto invalid;
+			break;
+		case DTE_BEQ:
+		case DTE_BNE:
+		case DTE_BLT:
+		case DTE_BLE:
+			if(a >= nregs || b >= nregs || i + 1 + c >= p->n)
+				goto invalid;
+			break;
+		case DTE_RET:
+			if(a >= nregs || b != 0 || c != 0)
+				goto invalid;
+			break;
+		case DTE_LDV:
+			if(a >= DTNVARS || b >= nregs)
+				goto invalid;
+			break;
+		case DTE_ZXT:
+		case DTE_SXT:
+			if(a >= nregs || b == 0 || b > 64 || c >= nregs)
+				goto invalid;
+		default: goto invalid;
+		}
+	}
+	if(p->n == 0 || p->b[p->n - 1] >> 24 != DTE_RET){
+		werrstr("must end with RET");
+		return -1;
+	}
+	return 0;
+
+invalid:
+	werrstr("invalid instruction %#.8ux @ %#.4ux", ins, i);
+	return -1;
+}
+
+int
+dtgverify(DTActGr *g)
+{
+	int i;
+
+	if(g->pred != nil && dteverify(g->pred) < 0)
+		return -1;
+	for(i = 0; i < g->nact; i++)
+		switch(g->acts[i].type){
+		case ACTTRACE:
+			if(g->acts[i].p == nil || dteverify(g->acts[i].p) < 0 || (uint)g->acts[i].size > 8)
+				return -1;
+			break;
+		case ACTTRACESTR:
+			if(g->acts[i].p == nil || dteverify(g->acts[i].p) < 0 || (uint)g->acts[i].size > DTRECMAX)
+				return -1;
+			break;
+		default:
+			return -1;
+		}
+	return 0;
+}
+
+typedef struct ExecInfo ExecInfo;
+struct ExecInfo {
+	int machno;
+	int epid;
+	u64int ts;
+	u64int arg[10];
+	DTChan *ch;
+};
+
+int
+dteexec(DTExpr *p, ExecInfo *info, s64int *retv)
+{
+	s64int R[16];
+	u32int ins;
+	u8int a, b, c;
+	int i;
+	
+	R[0] = 0;
+	for(i = 0;; i++){
+		ins = p->b[i];
+		a = ins >> 16;
+		b = ins >> 8;
+		c = ins;
+		switch(ins >> 24){
+		case DTE_ADD: R[c] = R[a] + R[b]; break;
+		case DTE_SUB: R[c] = R[a] - R[b]; break;
+		case DTE_MUL: R[c] = R[a] * R[b]; break;
+		case DTE_SDIV: if(R[b] == 0) goto div0; R[c] = R[a] / R[b]; break;
+		case DTE_SMOD: if(R[b] == 0) goto div0; R[c] = R[a] % R[b]; break;
+		case DTE_UDIV: if(R[b] == 0) goto div0; R[c] = (uvlong)R[a] / (uvlong)R[b]; break;
+		case DTE_UMOD: if(R[b] == 0) goto div0; R[c] = (uvlong)R[a] % (uvlong)R[b]; break;
+		case DTE_AND: R[c] = R[a] & R[b]; break;
+		case DTE_OR: R[c] = R[a] | R[b]; break;
+		case DTE_XOR: R[c] = R[a] ^ R[b]; break;
+		case DTE_XNOR: R[c] = ~(R[a] ^ R[b]); break;
+		case DTE_LDI: R[c] = (s64int)ins << 40 >> 54 << (ins >> 8 & 63); break;
+		case DTE_XORI: R[c] |= (s64int)ins << 40 >> 54 << (ins >> 8 & 63); break;
+		case DTE_LSL:
+			if((u64int)R[b] >= 64)
+				R[c] = 0;
+			else
+				R[c] = R[a] << R[b];
+			break;
+		case DTE_LSR:
+			if((u64int)R[b] >= 64)
+				R[c] = 0;
+			else
+				R[c] = (u64int)R[a] >> R[b];
+			break;
+		case DTE_ASR:
+			if((u64int)R[b] >= 64)
+				R[c] = R[a] >> 63;
+			else
+				R[c] = R[a] >> R[b];
+			break;
+		case DTE_SEQ: R[c] = R[a] == R[b]; break;
+		case DTE_SNE: R[c] = R[a] != R[b]; break;
+		case DTE_SLT: R[c] = R[a] < R[b]; break;
+		case DTE_SLE: R[c] = R[a] <= R[b]; break;
+		case DTE_BEQ: if(R[a] == R[b]) i += c; break;
+		case DTE_BNE: if(R[a] != R[b]) i += c; break;
+		case DTE_BLT: if(R[a] < R[b]) i += c; break;
+		case DTE_BLE: if(R[a] <= R[b]) i += c; break;
+		case DTE_LDV:
+			switch(a){
+			case DTV_ARG0:
+			case DTV_ARG1:
+			case DTV_ARG2:
+			case DTV_ARG3:
+			case DTV_ARG4:
+			case DTV_ARG5:
+			case DTV_ARG6:
+			case DTV_ARG7:
+			case DTV_ARG8:
+			case DTV_ARG9:
+				R[b] = info->arg[a - DTV_ARG0];
+				break;
+			case DTV_TIME: R[b] = info->ts; break;
+			case DTV_MACHNO: R[b] = info->machno; break;
+			default:
+				R[b] = dtgetvar(a);
+				break;
+			}
+		case DTE_ZXT: R[c] = (uvlong)R[a] << 64 - b >> 64 - b; break;
+		case DTE_SXT: R[c] = (vlong)R[a] << 64 - b >> 64 - b; break;
+		case DTE_RET: *retv = R[a]; return 0;
+		}
+	}
+
+div0:
+	snprint(info->ch->errstr, sizeof(info->ch->errstr), "division by zero");
+	return -1;
+}
+
+int
+dtpeekstr(uvlong addr, u8int *v, int len)
+{
+	int i;
+	
+	for(i = 0; i < len; i++){
+		if(addr + i < addr || dtpeek(addr + i, &v[i], 1) < 0){
+			memset(v, 0, len);
+			return -1;
+		}
+		if(v[i] == 0)
+			break;
+	}
+	if(i < len)
+		memset(&v[i], 0, len - i);
+	return 0;
+}
+
+#define PUT1(c) *bp++ = c;
+#define PUT2(c) *bp++ = c; *bp++ = c >> 8;
+#define PUT4(c) *bp++ = c; *bp++ = c >> 8; *bp++ = c >> 16; *bp++ = c >> 24;
+#define PUT8(c) PUT4(c); PUT4(c>>32);
+
+static int
+dtgexec(DTActGr *g, ExecInfo *info)
+{
+	DTBuf *b;
+	u8int *bp;
+	s64int v;
+	int i, j;
+	
+	b = g->chan->wrbufs[info->machno];
+	if(b->wr + g->reclen > DTBUFSZ)
+		return 0;
+	if(g->pred != nil){
+		if(dteexec(g->pred, info, &v) < 0)
+			return -1;
+		if(v == 0)
+			return 0;
+	}
+	bp = &b->data[b->wr];
+	PUT4(info->epid);
+	PUT8(info->ts);
+	for(i = 0; i < g->nact; i++){
+		if(dteexec(g->acts[i].p, info, &v) < 0)
+			return -1;
+		switch(g->acts[i].type){
+		case ACTTRACE:
+			for(j = 0; j < g->acts[i].size; j++){
+				*bp++ = v;
+				v >>= 8;
+			}
+			break;
+		case ACTTRACESTR:
+			if(dtpeekstr(v, bp, g->acts[i].size) < 0){
+				snprint(info->ch->errstr, sizeof(info->ch->errstr), "fault @ %#llux", v);
+				return -1;
+			}
+			bp += g->acts[i].size;
+			break;
+		}
+	}
+	assert(bp - b->data - b->wr == g->reclen);
+	b->wr = bp - b->data;
+	return 0;
+}
+
+void
+dtptrigger(DTProbe *p, int machno, uvlong arg0, uvlong arg1, uvlong arg2, uvlong arg3)
+{
+	DTEnab *e;
+	ExecInfo info;
+	
+	info.ts = dttime();
+	dtmachlock(machno);
+	info.machno = machno;
+	info.arg[0] = arg0;
+	info.arg[1] = arg1;
+	info.arg[2] = arg2;
+	info.arg[3] = arg3;
+	for(e = p->enablist.probnext; e != &p->enablist; e = e->probnext)
+		if(e->gr->chan->state == DTCGO){
+			info.ch = e->gr->chan;
+			info.epid = e->epid;
+			if(dtgexec(e->gr, &info) < 0)
+				e->gr->chan->state = DTCFAULT;
+		}
+	dtmachunlock(machno);
+}