/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END * * Portions Copyright 2006-2008 John Birrell jb@freebsd.org * Portions Copyright 2013 Justin Hibbits jhibbits@freebsd.org * * $FreeBSD$ * */ /* * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #include #include #include #include #include "fbt.h" #define FBT_PATCHVAL 0x7c810808 #define FBT_MFLR_R0 0x7c0802a6 #define FBT_MTLR_R0 0x7c0803a6 #define FBT_BLR 0x4e800020 #define FBT_BCTR 0x4e800030 #define FBT_BRANCH 0x48000000 #define FBT_BR_MASK 0x03fffffc #define FBT_IS_JUMP(instr) ((instr & ~FBT_BR_MASK) == FBT_BRANCH) #define FBT_ENTRY "entry" #define FBT_RETURN "return" #define FBT_AFRAMES 7 int fbt_invop(uintptr_t addr, uintptr_t *stack, uintptr_t rval) { struct trapframe *frame = (struct trapframe *)stack; solaris_cpu_t *cpu = &solaris_cpu[curcpu]; fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)]; uintptr_t tmp; for (; fbt != NULL; fbt = fbt->fbtp_hashnext) { if ((uintptr_t)fbt->fbtp_patchpoint == addr) { if (fbt->fbtp_roffset == 0) { cpu->cpu_dtrace_caller = addr; dtrace_probe(fbt->fbtp_id, frame->fixreg[3], frame->fixreg[4], frame->fixreg[5], frame->fixreg[6], frame->fixreg[7]); cpu->cpu_dtrace_caller = 0; } else { dtrace_probe(fbt->fbtp_id, fbt->fbtp_roffset, rval, 0, 0, 0); /* * The caller doesn't have the fbt item, so * fixup tail calls here. */ if (fbt->fbtp_rval == DTRACE_INVOP_JUMP) { frame->srr0 = (uintptr_t)fbt->fbtp_patchpoint; tmp = fbt->fbtp_savedval & FBT_BR_MASK; /* Sign extend. */ if (tmp & 0x02000000) #ifdef __powerpc64__ tmp |= 0xfffffffffc000000ULL; #else tmp |= 0xfc000000UL; #endif frame->srr0 += tmp; } cpu->cpu_dtrace_caller = 0; } return (fbt->fbtp_rval); } } return (0); } void fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val) { *fbt->fbtp_patchpoint = val; __syncicache(fbt->fbtp_patchpoint, 4); } int fbt_provide_module_function(linker_file_t lf, int symindx, linker_symval_t *symval, void *opaque) { char *modname = opaque; const char *name = symval->name; fbt_probe_t *fbt, *retfbt; int j; uint32_t *instr, *limit; #ifdef __powerpc64__ /* * PowerPC64 uses '.' prefixes on symbol names, ignore it, but only * allow symbols with the '.' prefix, so that we don't get the function * descriptor instead. */ if (name[0] == '.') name++; else return (0); #endif if (strncmp(name, "dtrace_", 7) == 0 && strncmp(name, "dtrace_safe_", 12) != 0) { /* * Anything beginning with "dtrace_" may be called * from probe context unless it explicitly indicates * that it won't be called from probe context by * using the prefix "dtrace_safe_". */ return (0); } if (name[0] == '_' && name[1] == '_') return (0); instr = (uint32_t *) symval->value; limit = (uint32_t *) (symval->value + symval->size); for (; instr < limit; instr++) if (*instr == FBT_MFLR_R0) break; if (*instr != FBT_MFLR_R0) return (0); fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); fbt->fbtp_name = name; fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, name, FBT_ENTRY, FBT_AFRAMES, fbt); fbt->fbtp_patchpoint = instr; fbt->fbtp_ctl = lf; fbt->fbtp_loadcnt = lf->loadcnt; fbt->fbtp_savedval = *instr; fbt->fbtp_patchval = FBT_PATCHVAL; fbt->fbtp_rval = DTRACE_INVOP_MFLR_R0; fbt->fbtp_symindx = symindx; fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; lf->fbt_nentries++; retfbt = NULL; again: if (instr >= limit) return (0); /* * We (desperately) want to avoid erroneously instrumenting a * jump table. To determine if we're looking at a true instruction * sequence or an inline jump table that happens to contain the same * byte sequences, we resort to some heuristic sleeze: we treat this * instruction as being contained within a pointer, and see if that * pointer points to within the body of the function. If it does, we * refuse to instrument it. */ { uint32_t *ptr; ptr = *(uint32_t **)instr; if (ptr >= (uint32_t *) symval->value && ptr < limit) { instr++; goto again; } } if (*instr != FBT_MTLR_R0) { instr++; goto again; } instr++; for (j = 0; j < 12 && instr < limit; j++, instr++) { if ((*instr == FBT_BCTR) || (*instr == FBT_BLR) || FBT_IS_JUMP(*instr)) break; } if (!(*instr == FBT_BCTR || *instr == FBT_BLR || FBT_IS_JUMP(*instr))) goto again; /* * We have a winner! */ fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); fbt->fbtp_name = name; if (retfbt == NULL) { fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, name, FBT_RETURN, FBT_AFRAMES, fbt); } else { retfbt->fbtp_next = fbt; fbt->fbtp_id = retfbt->fbtp_id; } retfbt = fbt; fbt->fbtp_patchpoint = instr; fbt->fbtp_ctl = lf; fbt->fbtp_loadcnt = lf->loadcnt; fbt->fbtp_symindx = symindx; if (*instr == FBT_BCTR) fbt->fbtp_rval = DTRACE_INVOP_BCTR; else if (*instr == FBT_BLR) fbt->fbtp_rval = DTRACE_INVOP_RET; else fbt->fbtp_rval = DTRACE_INVOP_JUMP; fbt->fbtp_roffset = (uintptr_t)((uint8_t *)instr - (uint8_t *)symval->value); fbt->fbtp_savedval = *instr; fbt->fbtp_patchval = FBT_PATCHVAL; fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; lf->fbt_nentries++; instr += 4; goto again; }