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/*
* 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
*
* $FreeBSD: release/9.1.0/sys/cddl/dev/fbt/fbt.c 179237 2008-05-23 05:59:42Z jb $
*
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/cpuvar.h>
#include <sys/fcntl.h>
#include <sys/filio.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/kmem.h>
#include <sys/kthread.h>
#include <sys/limits.h>
#include <sys/linker.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/pcpu.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/selinfo.h>
#include <sys/smp.h>
#include <sys/syscall.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/uio.h>
#include <sys/unistd.h>
#include <machine/stdarg.h>
#include <sys/dtrace.h>
#include <sys/dtrace_bsd.h>
MALLOC_DEFINE(M_FBT, "fbt", "Function Boundary Tracing");
#define FBT_PUSHL_EBP 0x55
#define FBT_MOVL_ESP_EBP0_V0 0x8b
#define FBT_MOVL_ESP_EBP1_V0 0xec
#define FBT_MOVL_ESP_EBP0_V1 0x89
#define FBT_MOVL_ESP_EBP1_V1 0xe5
#define FBT_REX_RSP_RBP 0x48
#define FBT_POPL_EBP 0x5d
#define FBT_RET 0xc3
#define FBT_RET_IMM16 0xc2
#define FBT_LEAVE 0xc9
#ifdef __amd64__
#define FBT_PATCHVAL 0xcc
#else
#define FBT_PATCHVAL 0xf0
#endif
static d_open_t fbt_open;
static int fbt_unload(void);
static void fbt_getargdesc(void *, dtrace_id_t, void *, dtrace_argdesc_t *);
static void fbt_provide_module(void *, modctl_t *);
static void fbt_destroy(void *, dtrace_id_t, void *);
static void fbt_enable(void *, dtrace_id_t, void *);
static void fbt_disable(void *, dtrace_id_t, void *);
static void fbt_load(void *);
static void fbt_suspend(void *, dtrace_id_t, void *);
static void fbt_resume(void *, dtrace_id_t, void *);
#define FBT_ENTRY "entry"
#define FBT_RETURN "return"
#define FBT_ADDR2NDX(addr) ((((uintptr_t)(addr)) >> 4) & fbt_probetab_mask)
#define FBT_PROBETAB_SIZE 0x8000 /* 32k entries -- 128K total */
static struct cdevsw fbt_cdevsw = {
.d_version = D_VERSION,
.d_open = fbt_open,
.d_name = "fbt",
};
static dtrace_pattr_t fbt_attr = {
{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
};
static dtrace_pops_t fbt_pops = {
NULL,
fbt_provide_module,
fbt_enable,
fbt_disable,
fbt_suspend,
fbt_resume,
fbt_getargdesc,
NULL,
NULL,
fbt_destroy
};
typedef struct fbt_probe {
struct fbt_probe *fbtp_hashnext;
uint8_t *fbtp_patchpoint;
int8_t fbtp_rval;
uint8_t fbtp_patchval;
uint8_t fbtp_savedval;
uintptr_t fbtp_roffset;
dtrace_id_t fbtp_id;
const char *fbtp_name;
modctl_t *fbtp_ctl;
int fbtp_loadcnt;
int fbtp_primary;
int fbtp_invop_cnt;
int fbtp_symindx;
struct fbt_probe *fbtp_next;
} fbt_probe_t;
static struct cdev *fbt_cdev;
static dtrace_provider_id_t fbt_id;
static fbt_probe_t **fbt_probetab;
static int fbt_probetab_size;
static int fbt_probetab_mask;
static int fbt_verbose = 0;
static void
fbt_doubletrap(void)
{
fbt_probe_t *fbt;
int i;
for (i = 0; i < fbt_probetab_size; i++) {
fbt = fbt_probetab[i];
for (; fbt != NULL; fbt = fbt->fbtp_next)
*fbt->fbtp_patchpoint = fbt->fbtp_savedval;
}
}
static int
fbt_invop(uintptr_t addr, uintptr_t *stack, uintptr_t rval)
{
solaris_cpu_t *cpu = &solaris_cpu[curcpu];
uintptr_t stack0, stack1, stack2, stack3, stack4;
fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)];
for (; fbt != NULL; fbt = fbt->fbtp_hashnext) {
if ((uintptr_t)fbt->fbtp_patchpoint == addr) {
fbt->fbtp_invop_cnt++;
if (fbt->fbtp_roffset == 0) {
int i = 0;
/*
* When accessing the arguments on the stack,
* we must protect against accessing beyond
* the stack. We can safely set NOFAULT here
* -- we know that interrupts are already
* disabled.
*/
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
cpu->cpu_dtrace_caller = stack[i++];
stack0 = stack[i++];
stack1 = stack[i++];
stack2 = stack[i++];
stack3 = stack[i++];
stack4 = stack[i++];
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT |
CPU_DTRACE_BADADDR);
dtrace_probe(fbt->fbtp_id, stack0, stack1,
stack2, stack3, stack4);
cpu->cpu_dtrace_caller = 0;
} else {
#ifdef __amd64__
/*
* On amd64, we instrument the ret, not the
* leave. We therefore need to set the caller
* to assure that the top frame of a stack()
* action is correct.
*/
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
cpu->cpu_dtrace_caller = stack[0];
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT |
CPU_DTRACE_BADADDR);
#endif
dtrace_probe(fbt->fbtp_id, fbt->fbtp_roffset,
rval, 0, 0, 0);
cpu->cpu_dtrace_caller = 0;
}
return (fbt->fbtp_rval);
}
}
return (0);
}
static 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;
int size;
u_int8_t *instr, *limit;
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);
size = symval->size;
instr = (u_int8_t *) symval->value;
limit = (u_int8_t *) symval->value + symval->size;
#ifdef __amd64__
while (instr < limit) {
if (*instr == FBT_PUSHL_EBP)
break;
if ((size = dtrace_instr_size(instr)) <= 0)
break;
instr += size;
}
if (instr >= limit || *instr != FBT_PUSHL_EBP) {
/*
* We either don't save the frame pointer in this
* function, or we ran into some disassembly
* screw-up. Either way, we bail.
*/
return (0);
}
#else
if (instr[0] != FBT_PUSHL_EBP)
return (0);
if (!(instr[1] == FBT_MOVL_ESP_EBP0_V0 &&
instr[2] == FBT_MOVL_ESP_EBP1_V0) &&
!(instr[1] == FBT_MOVL_ESP_EBP0_V1 &&
instr[2] == FBT_MOVL_ESP_EBP1_V1))
return (0);
#endif
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, 3, fbt);
fbt->fbtp_patchpoint = instr;
fbt->fbtp_ctl = lf;
fbt->fbtp_loadcnt = lf->loadcnt;
fbt->fbtp_rval = DTRACE_INVOP_PUSHL_EBP;
fbt->fbtp_savedval = *instr;
fbt->fbtp_patchval = FBT_PATCHVAL;
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);
/*
* If this disassembly fails, then we've likely walked off into
* a jump table or some other unsuitable area. Bail out of the
* disassembly now.
*/
if ((size = dtrace_instr_size(instr)) <= 0)
return (0);
#ifdef __amd64__
/*
* We only instrument "ret" on amd64 -- we don't yet instrument
* ret imm16, largely because the compiler doesn't seem to
* (yet) emit them in the kernel...
*/
if (*instr != FBT_RET) {
instr += size;
goto again;
}
#else
if (!(size == 1 &&
(*instr == FBT_POPL_EBP || *instr == FBT_LEAVE) &&
(*(instr + 1) == FBT_RET ||
*(instr + 1) == FBT_RET_IMM16))) {
instr += size;
goto again;
}
#endif
/*
* We (desperately) want to avoid erroneously instrumenting a
* jump table, especially given that our markers are pretty
* short: two bytes on x86, and just one byte on amd64. 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.
*/
for (j = 0; j < sizeof (uintptr_t); j++) {
caddr_t check = (caddr_t) instr - j;
uint8_t *ptr;
if (check < symval->value)
break;
if (check + sizeof (caddr_t) > (caddr_t)limit)
continue;
ptr = *(uint8_t **)check;
if (ptr >= (uint8_t *) symval->value && ptr < limit) {
instr += size;
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, 3, 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;
#ifndef __amd64__
if (*instr == FBT_POPL_EBP) {
fbt->fbtp_rval = DTRACE_INVOP_POPL_EBP;
} else {
ASSERT(*instr == FBT_LEAVE);
fbt->fbtp_rval = DTRACE_INVOP_LEAVE;
}
fbt->fbtp_roffset =
(uintptr_t)(instr - (uint8_t *) symval->value) + 1;
#else
ASSERT(*instr == FBT_RET);
fbt->fbtp_rval = DTRACE_INVOP_RET;
fbt->fbtp_roffset =
(uintptr_t)(instr - (uint8_t *) symval->value);
#endif
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 += size;
goto again;
}
static void
fbt_provide_module(void *arg, modctl_t *lf)
{
char modname[MAXPATHLEN];
int i;
size_t len;
strlcpy(modname, lf->filename, sizeof(modname));
len = strlen(modname);
if (len > 3 && strcmp(modname + len - 3, ".ko") == 0)
modname[len - 3] = '\0';
/*
* Employees of dtrace and their families are ineligible. Void
* where prohibited.
*/
if (strcmp(modname, "dtrace") == 0)
return;
/*
* The cyclic timer subsystem can be built as a module and DTrace
* depends on that, so it is ineligible too.
*/
if (strcmp(modname, "cyclic") == 0)
return;
/*
* To register with DTrace, a module must list 'dtrace' as a
* dependency in order for the kernel linker to resolve
* symbols like dtrace_register(). All modules with such a
* dependency are ineligible for FBT tracing.
*/
for (i = 0; i < lf->ndeps; i++)
if (strncmp(lf->deps[i]->filename, "dtrace", 6) == 0)
return;
if (lf->fbt_nentries) {
/*
* This module has some FBT entries allocated; we're afraid
* to screw with it.
*/
return;
}
/*
* List the functions in the module and the symbol values.
*/
(void) linker_file_function_listall(lf, fbt_provide_module_function, modname);
}
static void
fbt_destroy(void *arg, dtrace_id_t id, void *parg)
{
fbt_probe_t *fbt = parg, *next, *hash, *last;
modctl_t *ctl;
int ndx;
do {
ctl = fbt->fbtp_ctl;
ctl->fbt_nentries--;
/*
* Now we need to remove this probe from the fbt_probetab.
*/
ndx = FBT_ADDR2NDX(fbt->fbtp_patchpoint);
last = NULL;
hash = fbt_probetab[ndx];
while (hash != fbt) {
ASSERT(hash != NULL);
last = hash;
hash = hash->fbtp_hashnext;
}
if (last != NULL) {
last->fbtp_hashnext = fbt->fbtp_hashnext;
} else {
fbt_probetab[ndx] = fbt->fbtp_hashnext;
}
next = fbt->fbtp_next;
free(fbt, M_FBT);
fbt = next;
} while (fbt != NULL);
}
static void
fbt_enable(void *arg, dtrace_id_t id, void *parg)
{
fbt_probe_t *fbt = parg;
modctl_t *ctl = fbt->fbtp_ctl;
ctl->nenabled++;
/*
* Now check that our modctl has the expected load count. If it
* doesn't, this module must have been unloaded and reloaded -- and
* we're not going to touch it.
*/
if (ctl->loadcnt != fbt->fbtp_loadcnt) {
if (fbt_verbose) {
printf("fbt is failing for probe %s "
"(module %s reloaded)",
fbt->fbtp_name, ctl->filename);
}
return;
}
for (; fbt != NULL; fbt = fbt->fbtp_next) {
*fbt->fbtp_patchpoint = fbt->fbtp_patchval;
}
}
static void
fbt_disable(void *arg, dtrace_id_t id, void *parg)
{
fbt_probe_t *fbt = parg;
modctl_t *ctl = fbt->fbtp_ctl;
ASSERT(ctl->nenabled > 0);
ctl->nenabled--;
if ((ctl->loadcnt != fbt->fbtp_loadcnt))
return;
for (; fbt != NULL; fbt = fbt->fbtp_next)
*fbt->fbtp_patchpoint = fbt->fbtp_savedval;
}
static void
fbt_suspend(void *arg, dtrace_id_t id, void *parg)
{
fbt_probe_t *fbt = parg;
modctl_t *ctl = fbt->fbtp_ctl;
ASSERT(ctl->nenabled > 0);
if ((ctl->loadcnt != fbt->fbtp_loadcnt))
return;
for (; fbt != NULL; fbt = fbt->fbtp_next)
*fbt->fbtp_patchpoint = fbt->fbtp_savedval;
}
static void
fbt_resume(void *arg, dtrace_id_t id, void *parg)
{
fbt_probe_t *fbt = parg;
modctl_t *ctl = fbt->fbtp_ctl;
ASSERT(ctl->nenabled > 0);
if ((ctl->loadcnt != fbt->fbtp_loadcnt))
return;
for (; fbt != NULL; fbt = fbt->fbtp_next)
*fbt->fbtp_patchpoint = fbt->fbtp_patchval;
}
static int
fbt_ctfoff_init(modctl_t *lf, linker_ctf_t *lc)
{
const Elf_Sym *symp = lc->symtab;;
const char *name;
const ctf_header_t *hp = (const ctf_header_t *) lc->ctftab;
const uint8_t *ctfdata = lc->ctftab + sizeof(ctf_header_t);
int i;
uint32_t *ctfoff;
uint32_t objtoff = hp->cth_objtoff;
uint32_t funcoff = hp->cth_funcoff;
ushort_t info;
ushort_t vlen;
/* Sanity check. */
if (hp->cth_magic != CTF_MAGIC) {
printf("Bad magic value in CTF data of '%s'\n",lf->pathname);
return (EINVAL);
}
if (lc->symtab == NULL) {
printf("No symbol table in '%s'\n",lf->pathname);
return (EINVAL);
}
if ((ctfoff = malloc(sizeof(uint32_t) * lc->nsym, M_LINKER, M_WAITOK)) == NULL)
return (ENOMEM);
*lc->ctfoffp = ctfoff;
for (i = 0; i < lc->nsym; i++, ctfoff++, symp++) {
if (symp->st_name == 0 || symp->st_shndx == SHN_UNDEF) {
*ctfoff = 0xffffffff;
continue;
}
if (symp->st_name < lc->strcnt)
name = lc->strtab + symp->st_name;
else
name = "(?)";
switch (ELF_ST_TYPE(symp->st_info)) {
case STT_OBJECT:
if (objtoff >= hp->cth_funcoff ||
(symp->st_shndx == SHN_ABS && symp->st_value == 0)) {
*ctfoff = 0xffffffff;
break;
}
*ctfoff = objtoff;
objtoff += sizeof (ushort_t);
break;
case STT_FUNC:
if (funcoff >= hp->cth_typeoff) {
*ctfoff = 0xffffffff;
break;
}
*ctfoff = funcoff;
info = *((const ushort_t *)(ctfdata + funcoff));
vlen = CTF_INFO_VLEN(info);
/*
* If we encounter a zero pad at the end, just skip it.
* Otherwise skip over the function and its return type
* (+2) and the argument list (vlen).
*/
if (CTF_INFO_KIND(info) == CTF_K_UNKNOWN && vlen == 0)
funcoff += sizeof (ushort_t); /* skip pad */
else
funcoff += sizeof (ushort_t) * (vlen + 2);
break;
default:
*ctfoff = 0xffffffff;
break;
}
}
return (0);
}
static ssize_t
fbt_get_ctt_size(uint8_t version, const ctf_type_t *tp, ssize_t *sizep,
ssize_t *incrementp)
{
ssize_t size, increment;
if (version > CTF_VERSION_1 &&
tp->ctt_size == CTF_LSIZE_SENT) {
size = CTF_TYPE_LSIZE(tp);
increment = sizeof (ctf_type_t);
} else {
size = tp->ctt_size;
increment = sizeof (ctf_stype_t);
}
if (sizep)
*sizep = size;
if (incrementp)
*incrementp = increment;
return (size);
}
static int
fbt_typoff_init(linker_ctf_t *lc)
{
const ctf_header_t *hp = (const ctf_header_t *) lc->ctftab;
const ctf_type_t *tbuf;
const ctf_type_t *tend;
const ctf_type_t *tp;
const uint8_t *ctfdata = lc->ctftab + sizeof(ctf_header_t);
int ctf_typemax = 0;
uint32_t *xp;
ulong_t pop[CTF_K_MAX + 1] = { 0 };
/* Sanity check. */
if (hp->cth_magic != CTF_MAGIC)
return (EINVAL);
tbuf = (const ctf_type_t *) (ctfdata + hp->cth_typeoff);
tend = (const ctf_type_t *) (ctfdata + hp->cth_stroff);
int child = hp->cth_parname != 0;
/*
* We make two passes through the entire type section. In this first
* pass, we count the number of each type and the total number of types.
*/
for (tp = tbuf; tp < tend; ctf_typemax++) {
ushort_t kind = CTF_INFO_KIND(tp->ctt_info);
ulong_t vlen = CTF_INFO_VLEN(tp->ctt_info);
ssize_t size, increment;
size_t vbytes;
uint_t n;
(void) fbt_get_ctt_size(hp->cth_version, tp, &size, &increment);
switch (kind) {
case CTF_K_INTEGER:
case CTF_K_FLOAT:
vbytes = sizeof (uint_t);
break;
case CTF_K_ARRAY:
vbytes = sizeof (ctf_array_t);
break;
case CTF_K_FUNCTION:
vbytes = sizeof (ushort_t) * (vlen + (vlen & 1));
break;
case CTF_K_STRUCT:
case CTF_K_UNION:
if (size < CTF_LSTRUCT_THRESH) {
ctf_member_t *mp = (ctf_member_t *)
((uintptr_t)tp + increment);
vbytes = sizeof (ctf_member_t) * vlen;
for (n = vlen; n != 0; n--, mp++)
child |= CTF_TYPE_ISCHILD(mp->ctm_type);
} else {
ctf_lmember_t *lmp = (ctf_lmember_t *)
((uintptr_t)tp + increment);
vbytes = sizeof (ctf_lmember_t) * vlen;
for (n = vlen; n != 0; n--, lmp++)
child |=
CTF_TYPE_ISCHILD(lmp->ctlm_type);
}
break;
case CTF_K_ENUM:
vbytes = sizeof (ctf_enum_t) * vlen;
break;
case CTF_K_FORWARD:
/*
* For forward declarations, ctt_type is the CTF_K_*
* kind for the tag, so bump that population count too.
* If ctt_type is unknown, treat the tag as a struct.
*/
if (tp->ctt_type == CTF_K_UNKNOWN ||
tp->ctt_type >= CTF_K_MAX)
pop[CTF_K_STRUCT]++;
else
pop[tp->ctt_type]++;
/*FALLTHRU*/
case CTF_K_UNKNOWN:
vbytes = 0;
break;
case CTF_K_POINTER:
case CTF_K_TYPEDEF:
case CTF_K_VOLATILE:
case CTF_K_CONST:
case CTF_K_RESTRICT:
child |= CTF_TYPE_ISCHILD(tp->ctt_type);
vbytes = 0;
break;
default:
printf("%s(%d): detected invalid CTF kind -- %u\n", __func__, __LINE__, kind);
return (EIO);
}
tp = (ctf_type_t *)((uintptr_t)tp + increment + vbytes);
pop[kind]++;
}
*lc->typlenp = ctf_typemax;
if ((xp = malloc(sizeof(uint32_t) * ctf_typemax, M_LINKER, M_ZERO | M_WAITOK)) == NULL)
return (ENOMEM);
*lc->typoffp = xp;
/* type id 0 is used as a sentinel value */
*xp++ = 0;
/*
* In the second pass, fill in the type offset.
*/
for (tp = tbuf; tp < tend; xp++) {
ushort_t kind = CTF_INFO_KIND(tp->ctt_info);
ulong_t vlen = CTF_INFO_VLEN(tp->ctt_info);
ssize_t size, increment;
size_t vbytes;
uint_t n;
(void) fbt_get_ctt_size(hp->cth_version, tp, &size, &increment);
switch (kind) {
case CTF_K_INTEGER:
case CTF_K_FLOAT:
vbytes = sizeof (uint_t);
break;
case CTF_K_ARRAY:
vbytes = sizeof (ctf_array_t);
break;
case CTF_K_FUNCTION:
vbytes = sizeof (ushort_t) * (vlen + (vlen & 1));
break;
case CTF_K_STRUCT:
case CTF_K_UNION:
if (size < CTF_LSTRUCT_THRESH) {
ctf_member_t *mp = (ctf_member_t *)
((uintptr_t)tp + increment);
vbytes = sizeof (ctf_member_t) * vlen;
for (n = vlen; n != 0; n--, mp++)
child |= CTF_TYPE_ISCHILD(mp->ctm_type);
} else {
ctf_lmember_t *lmp = (ctf_lmember_t *)
((uintptr_t)tp + increment);
vbytes = sizeof (ctf_lmember_t) * vlen;
for (n = vlen; n != 0; n--, lmp++)
child |=
CTF_TYPE_ISCHILD(lmp->ctlm_type);
}
break;
case CTF_K_ENUM:
vbytes = sizeof (ctf_enum_t) * vlen;
break;
case CTF_K_FORWARD:
case CTF_K_UNKNOWN:
vbytes = 0;
break;
case CTF_K_POINTER:
case CTF_K_TYPEDEF:
case CTF_K_VOLATILE:
case CTF_K_CONST:
case CTF_K_RESTRICT:
vbytes = 0;
break;
default:
printf("%s(%d): detected invalid CTF kind -- %u\n", __func__, __LINE__, kind);
return (EIO);
}
*xp = (uint32_t)((uintptr_t) tp - (uintptr_t) ctfdata);
tp = (ctf_type_t *)((uintptr_t)tp + increment + vbytes);
}
return (0);
}
/*
* CTF Declaration Stack
*
* In order to implement ctf_type_name(), we must convert a type graph back
* into a C type declaration. Unfortunately, a type graph represents a storage
* class ordering of the type whereas a type declaration must obey the C rules
* for operator precedence, and the two orderings are frequently in conflict.
* For example, consider these CTF type graphs and their C declarations:
*
* CTF_K_POINTER -> CTF_K_FUNCTION -> CTF_K_INTEGER : int (*)()
* CTF_K_POINTER -> CTF_K_ARRAY -> CTF_K_INTEGER : int (*)[]
*
* In each case, parentheses are used to raise operator * to higher lexical
* precedence, so the string form of the C declaration cannot be constructed by
* walking the type graph links and forming the string from left to right.
*
* The functions in this file build a set of stacks from the type graph nodes
* corresponding to the C operator precedence levels in the appropriate order.
* The code in ctf_type_name() can then iterate over the levels and nodes in
* lexical precedence order and construct the final C declaration string.
*/
typedef struct ctf_list {
struct ctf_list *l_prev; /* previous pointer or tail pointer */
struct ctf_list *l_next; /* next pointer or head pointer */
} ctf_list_t;
#define ctf_list_prev(elem) ((void *)(((ctf_list_t *)(elem))->l_prev))
#define ctf_list_next(elem) ((void *)(((ctf_list_t *)(elem))->l_next))
typedef enum {
CTF_PREC_BASE,
CTF_PREC_POINTER,
CTF_PREC_ARRAY,
CTF_PREC_FUNCTION,
CTF_PREC_MAX
} ctf_decl_prec_t;
typedef struct ctf_decl_node {
ctf_list_t cd_list; /* linked list pointers */
ctf_id_t cd_type; /* type identifier */
uint_t cd_kind; /* type kind */
uint_t cd_n; /* type dimension if array */
} ctf_decl_node_t;
typedef struct ctf_decl {
ctf_list_t cd_nodes[CTF_PREC_MAX]; /* declaration node stacks */
int cd_order[CTF_PREC_MAX]; /* storage order of decls */
ctf_decl_prec_t cd_qualp; /* qualifier precision */
ctf_decl_prec_t cd_ordp; /* ordered precision */
char *cd_buf; /* buffer for output */
char *cd_ptr; /* buffer location */
char *cd_end; /* buffer limit */
size_t cd_len; /* buffer space required */
int cd_err; /* saved error value */
} ctf_decl_t;
/*
* Simple doubly-linked list append routine. This implementation assumes that
* each list element contains an embedded ctf_list_t as the first member.
* An additional ctf_list_t is used to store the head (l_next) and tail
* (l_prev) pointers. The current head and tail list elements have their
* previous and next pointers set to NULL, respectively.
*/
static void
ctf_list_append(ctf_list_t *lp, void *new)
{
ctf_list_t *p = lp->l_prev; /* p = tail list element */
ctf_list_t *q = new; /* q = new list element */
lp->l_prev = q;
q->l_prev = p;
q->l_next = NULL;
if (p != NULL)
p->l_next = q;
else
lp->l_next = q;
}
/*
* Prepend the specified existing element to the given ctf_list_t. The
* existing pointer should be pointing at a struct with embedded ctf_list_t.
*/
static void
ctf_list_prepend(ctf_list_t *lp, void *new)
{
ctf_list_t *p = new; /* p = new list element */
ctf_list_t *q = lp->l_next; /* q = head list element */
lp->l_next = p;
p->l_prev = NULL;
p->l_next = q;
if (q != NULL)
q->l_prev = p;
else
lp->l_prev = p;
}
static void
ctf_decl_init(ctf_decl_t *cd, char *buf, size_t len)
{
int i;
bzero(cd, sizeof (ctf_decl_t));
for (i = CTF_PREC_BASE; i < CTF_PREC_MAX; i++)
cd->cd_order[i] = CTF_PREC_BASE - 1;
cd->cd_qualp = CTF_PREC_BASE;
cd->cd_ordp = CTF_PREC_BASE;
cd->cd_buf = buf;
cd->cd_ptr = buf;
cd->cd_end = buf + len;
}
static void
ctf_decl_fini(ctf_decl_t *cd)
{
ctf_decl_node_t *cdp, *ndp;
int i;
for (i = CTF_PREC_BASE; i < CTF_PREC_MAX; i++) {
for (cdp = ctf_list_next(&cd->cd_nodes[i]);
cdp != NULL; cdp = ndp) {
ndp = ctf_list_next(cdp);
free(cdp, M_FBT);
}
}
}
static const ctf_type_t *
ctf_lookup_by_id(linker_ctf_t *lc, ctf_id_t type)
{
const ctf_type_t *tp;
uint32_t offset;
uint32_t *typoff = *lc->typoffp;
if (type >= *lc->typlenp) {
printf("%s(%d): type %d exceeds max %ld\n",__func__,__LINE__,(int) type,*lc->typlenp);
return(NULL);
}
/* Check if the type isn't cross-referenced. */
if ((offset = typoff[type]) == 0) {
printf("%s(%d): type %d isn't cross referenced\n",__func__,__LINE__, (int) type);
return(NULL);
}
tp = (const ctf_type_t *)(lc->ctftab + offset + sizeof(ctf_header_t));
return (tp);
}
static void
fbt_array_info(linker_ctf_t *lc, ctf_id_t type, ctf_arinfo_t *arp)
{
const ctf_header_t *hp = (const ctf_header_t *) lc->ctftab;
const ctf_type_t *tp;
const ctf_array_t *ap;
ssize_t increment;
bzero(arp, sizeof(*arp));
if ((tp = ctf_lookup_by_id(lc, type)) == NULL)
return;
if (CTF_INFO_KIND(tp->ctt_info) != CTF_K_ARRAY)
return;
(void) fbt_get_ctt_size(hp->cth_version, tp, NULL, &increment);
ap = (const ctf_array_t *)((uintptr_t)tp + increment);
arp->ctr_contents = ap->cta_contents;
arp->ctr_index = ap->cta_index;
arp->ctr_nelems = ap->cta_nelems;
}
static const char *
ctf_strptr(linker_ctf_t *lc, int name)
{
const ctf_header_t *hp = (const ctf_header_t *) lc->ctftab;;
const char *strp = "";
if (name < 0 || name >= hp->cth_strlen)
return(strp);
strp = (const char *)(lc->ctftab + hp->cth_stroff + name + sizeof(ctf_header_t));
return (strp);
}
static void
ctf_decl_push(ctf_decl_t *cd, linker_ctf_t *lc, ctf_id_t type)
{
ctf_decl_node_t *cdp;
ctf_decl_prec_t prec;
uint_t kind, n = 1;
int is_qual = 0;
const ctf_type_t *tp;
ctf_arinfo_t ar;
if ((tp = ctf_lookup_by_id(lc, type)) == NULL) {
cd->cd_err = ENOENT;
return;
}
switch (kind = CTF_INFO_KIND(tp->ctt_info)) {
case CTF_K_ARRAY:
fbt_array_info(lc, type, &ar);
ctf_decl_push(cd, lc, ar.ctr_contents);
n = ar.ctr_nelems;
prec = CTF_PREC_ARRAY;
break;
case CTF_K_TYPEDEF:
if (ctf_strptr(lc, tp->ctt_name)[0] == '\0') {
ctf_decl_push(cd, lc, tp->ctt_type);
return;
}
prec = CTF_PREC_BASE;
break;
case CTF_K_FUNCTION:
ctf_decl_push(cd, lc, tp->ctt_type);
prec = CTF_PREC_FUNCTION;
break;
case CTF_K_POINTER:
ctf_decl_push(cd, lc, tp->ctt_type);
prec = CTF_PREC_POINTER;
break;
case CTF_K_VOLATILE:
case CTF_K_CONST:
case CTF_K_RESTRICT:
ctf_decl_push(cd, lc, tp->ctt_type);
prec = cd->cd_qualp;
is_qual++;
break;
default:
prec = CTF_PREC_BASE;
}
if ((cdp = malloc(sizeof (ctf_decl_node_t), M_FBT, M_WAITOK)) == NULL) {
cd->cd_err = EAGAIN;
return;
}
cdp->cd_type = type;
cdp->cd_kind = kind;
cdp->cd_n = n;
if (ctf_list_next(&cd->cd_nodes[prec]) == NULL)
cd->cd_order[prec] = cd->cd_ordp++;
/*
* Reset cd_qualp to the highest precedence level that we've seen so
* far that can be qualified (CTF_PREC_BASE or CTF_PREC_POINTER).
*/
if (prec > cd->cd_qualp && prec < CTF_PREC_ARRAY)
cd->cd_qualp = prec;
/*
* C array declarators are ordered inside out so prepend them. Also by
* convention qualifiers of base types precede the type specifier (e.g.
* const int vs. int const) even though the two forms are equivalent.
*/
if (kind == CTF_K_ARRAY || (is_qual && prec == CTF_PREC_BASE))
ctf_list_prepend(&cd->cd_nodes[prec], cdp);
else
ctf_list_append(&cd->cd_nodes[prec], cdp);
}
static void
ctf_decl_sprintf(ctf_decl_t *cd, const char *format, ...)
{
size_t len = (size_t)(cd->cd_end - cd->cd_ptr);
va_list ap;
size_t n;
va_start(ap, format);
n = vsnprintf(cd->cd_ptr, len, format, ap);
va_end(ap);
cd->cd_ptr += MIN(n, len);
cd->cd_len += n;
}
static ssize_t
fbt_type_name(linker_ctf_t *lc, ctf_id_t type, char *buf, size_t len)
{
ctf_decl_t cd;
ctf_decl_node_t *cdp;
ctf_decl_prec_t prec, lp, rp;
int ptr, arr;
uint_t k;
if (lc == NULL && type == CTF_ERR)
return (-1); /* simplify caller code by permitting CTF_ERR */
ctf_decl_init(&cd, buf, len);
ctf_decl_push(&cd, lc, type);
if (cd.cd_err != 0) {
ctf_decl_fini(&cd);
return (-1);
}
/*
* If the type graph's order conflicts with lexical precedence order
* for pointers or arrays, then we need to surround the declarations at
* the corresponding lexical precedence with parentheses. This can
* result in either a parenthesized pointer (*) as in int (*)() or
* int (*)[], or in a parenthesized pointer and array as in int (*[])().
*/
ptr = cd.cd_order[CTF_PREC_POINTER] > CTF_PREC_POINTER;
arr = cd.cd_order[CTF_PREC_ARRAY] > CTF_PREC_ARRAY;
rp = arr ? CTF_PREC_ARRAY : ptr ? CTF_PREC_POINTER : -1;
lp = ptr ? CTF_PREC_POINTER : arr ? CTF_PREC_ARRAY : -1;
k = CTF_K_POINTER; /* avoid leading whitespace (see below) */
for (prec = CTF_PREC_BASE; prec < CTF_PREC_MAX; prec++) {
for (cdp = ctf_list_next(&cd.cd_nodes[prec]);
cdp != NULL; cdp = ctf_list_next(cdp)) {
const ctf_type_t *tp =
ctf_lookup_by_id(lc, cdp->cd_type);
const char *name = ctf_strptr(lc, tp->ctt_name);
if (k != CTF_K_POINTER && k != CTF_K_ARRAY)
ctf_decl_sprintf(&cd, " ");
if (lp == prec) {
ctf_decl_sprintf(&cd, "(");
lp = -1;
}
switch (cdp->cd_kind) {
case CTF_K_INTEGER:
case CTF_K_FLOAT:
case CTF_K_TYPEDEF:
ctf_decl_sprintf(&cd, "%s", name);
break;
case CTF_K_POINTER:
ctf_decl_sprintf(&cd, "*");
break;
case CTF_K_ARRAY:
ctf_decl_sprintf(&cd, "[%u]", cdp->cd_n);
break;
case CTF_K_FUNCTION:
ctf_decl_sprintf(&cd, "()");
break;
case CTF_K_STRUCT:
case CTF_K_FORWARD:
ctf_decl_sprintf(&cd, "struct %s", name);
break;
case CTF_K_UNION:
ctf_decl_sprintf(&cd, "union %s", name);
break;
case CTF_K_ENUM:
ctf_decl_sprintf(&cd, "enum %s", name);
break;
case CTF_K_VOLATILE:
ctf_decl_sprintf(&cd, "volatile");
break;
case CTF_K_CONST:
ctf_decl_sprintf(&cd, "const");
break;
case CTF_K_RESTRICT:
ctf_decl_sprintf(&cd, "restrict");
break;
}
k = cdp->cd_kind;
}
if (rp == prec)
ctf_decl_sprintf(&cd, ")");
}
ctf_decl_fini(&cd);
return (cd.cd_len);
}
static void
fbt_getargdesc(void *arg __unused, dtrace_id_t id __unused, void *parg, dtrace_argdesc_t *desc)
{
const ushort_t *dp;
fbt_probe_t *fbt = parg;
linker_ctf_t lc;
modctl_t *ctl = fbt->fbtp_ctl;
int ndx = desc->dtargd_ndx;
int symindx = fbt->fbtp_symindx;
uint32_t *ctfoff;
uint32_t offset;
ushort_t info, kind, n;
desc->dtargd_ndx = DTRACE_ARGNONE;
/* Get a pointer to the CTF data and it's length. */
if (linker_ctf_get(ctl, &lc) != 0)
/* No CTF data? Something wrong? *shrug* */
return;
/* Check if this module hasn't been initialised yet. */
if (*lc.ctfoffp == NULL) {
/*
* Initialise the CTF object and function symindx to
* byte offset array.
*/
if (fbt_ctfoff_init(ctl, &lc) != 0)
return;
/* Initialise the CTF type to byte offset array. */
if (fbt_typoff_init(&lc) != 0)
return;
}
ctfoff = *lc.ctfoffp;
if (ctfoff == NULL || *lc.typoffp == NULL)
return;
/* Check if the symbol index is out of range. */
if (symindx >= lc.nsym)
return;
/* Check if the symbol isn't cross-referenced. */
if ((offset = ctfoff[symindx]) == 0xffffffff)
return;
dp = (const ushort_t *)(lc.ctftab + offset + sizeof(ctf_header_t));
info = *dp++;
kind = CTF_INFO_KIND(info);
n = CTF_INFO_VLEN(info);
if (kind == CTF_K_UNKNOWN && n == 0) {
printf("%s(%d): Unknown function!\n",__func__,__LINE__);
return;
}
if (kind != CTF_K_FUNCTION) {
printf("%s(%d): Expected a function!\n",__func__,__LINE__);
return;
}
/* Check if the requested argument doesn't exist. */
if (ndx >= n)
return;
/* Skip the return type and arguments up to the one requested. */
dp += ndx + 1;
if (fbt_type_name(&lc, *dp, desc->dtargd_native, sizeof(desc->dtargd_native)) > 0)
desc->dtargd_ndx = ndx;
return;
}
static void
fbt_load(void *dummy)
{
/* Create the /dev/dtrace/fbt entry. */
fbt_cdev = make_dev(&fbt_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
"dtrace/fbt");
/* Default the probe table size if not specified. */
if (fbt_probetab_size == 0)
fbt_probetab_size = FBT_PROBETAB_SIZE;
/* Choose the hash mask for the probe table. */
fbt_probetab_mask = fbt_probetab_size - 1;
/* Allocate memory for the probe table. */
fbt_probetab =
malloc(fbt_probetab_size * sizeof (fbt_probe_t *), M_FBT, M_WAITOK | M_ZERO);
dtrace_doubletrap_func = fbt_doubletrap;
dtrace_invop_add(fbt_invop);
if (dtrace_register("fbt", &fbt_attr, DTRACE_PRIV_USER,
NULL, &fbt_pops, NULL, &fbt_id) != 0)
return;
}
static int
fbt_unload()
{
int error = 0;
/* De-register the invalid opcode handler. */
dtrace_invop_remove(fbt_invop);
dtrace_doubletrap_func = NULL;
/* De-register this DTrace provider. */
if ((error = dtrace_unregister(fbt_id)) != 0)
return (error);
/* Free the probe table. */
free(fbt_probetab, M_FBT);
fbt_probetab = NULL;
fbt_probetab_mask = 0;
destroy_dev(fbt_cdev);
return (error);
}
static int
fbt_modevent(module_t mod __unused, int type, void *data __unused)
{
int error = 0;
switch (type) {
case MOD_LOAD:
break;
case MOD_UNLOAD:
break;
case MOD_SHUTDOWN:
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
static int
fbt_open(struct cdev *dev __unused, int oflags __unused, int devtype __unused, struct thread *td __unused)
{
return (0);
}
SYSINIT(fbt_load, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, fbt_load, NULL);
SYSUNINIT(fbt_unload, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, fbt_unload, NULL);
DEV_MODULE(fbt, fbt_modevent, NULL);
MODULE_VERSION(fbt, 1);
MODULE_DEPEND(fbt, dtrace, 1, 1, 1);
MODULE_DEPEND(fbt, opensolaris, 1, 1, 1);