ref: c5393d612fd2a0e4ff3f9557dcb6adb2ad27391f
dir: /sys/src/libdtracy/prog.c/
#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; break; 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); }