int
proc_bkptset(struct proc_handle *phdl, uintptr_t address,
unsigned long *saved)
{
struct ptrace_io_desc piod;
unsigned long paddr, caddr;
int ret = 0;
*saved = 0;
if (phdl->status == PS_DEAD || phdl->status == PS_UNDEAD ||
phdl->status == PS_IDLE) {
errno = ENOENT;
return (-1);
}
DPRINTFX("adding breakpoint at 0x%lx", address);
if (phdl->status != PS_STOP)
if (proc_stop(phdl) != 0)
return (-1);
/*
* Read the original instruction.
*/
caddr = address;
paddr = 0;
piod.piod_op = PIOD_READ_I;
piod.piod_offs = (void *)caddr;
piod.piod_addr = &paddr;
piod.piod_len = BREAKPOINT_INSTR_SZ;
if (ptrace(PT_IO, proc_getpid(phdl), (caddr_t)&piod, 0) < 0) {
DPRINTF("ERROR: couldn't read instruction at address 0x%"
PRIuPTR, address);
ret = -1;
goto done;
}
*saved = paddr;
/*
* Write a breakpoint instruction to that address.
*/
caddr = address;
paddr = BREAKPOINT_INSTR;
piod.piod_op = PIOD_WRITE_I;
piod.piod_offs = (void *)caddr;
piod.piod_addr = &paddr;
piod.piod_len = BREAKPOINT_INSTR_SZ;
if (ptrace(PT_IO, proc_getpid(phdl), (caddr_t)&piod, 0) < 0) {
DPRINTF("ERROR: couldn't write instruction at address 0x%"
PRIuPTR, address);
ret = -1;
goto done;
}
done:
if (phdl->status != PS_STOP)
/* Restart the process if we had to stop it. */
proc_cont(phdl);
return (ret);
}
int
proc_regset(struct proc_handle *phdl, proc_reg_t reg, unsigned long regvalue)
{
struct reg regs;
if (phdl->status == PS_DEAD || phdl->status == PS_UNDEAD ||
phdl->status == PS_IDLE) {
errno = ENOENT;
return (-1);
}
if (ptrace(PT_GETREGS, proc_getpid(phdl), (caddr_t)®s, 0) < 0)
return (-1);
switch (reg) {
case REG_PC:
#if defined(__aarch64__)
regs.elr = regvalue;
#elif defined(__amd64__)
regs.r_rip = regvalue;
#elif defined(__arm__)
regs.r_pc = regvalue;
#elif defined(__i386__)
regs.r_eip = regvalue;
#elif defined(__mips__)
regs.r_regs[PC] = regvalue;
#elif defined(__powerpc__)
regs.pc = regvalue;
#elif defined(__riscv__)
regs.sepc = regvalue;
#endif
break;
case REG_SP:
#if defined(__aarch64__)
regs.sp = regvalue;
#elif defined(__amd64__)
regs.r_rsp = regvalue;
#elif defined(__arm__)
regs.r_sp = regvalue;
#elif defined(__i386__)
regs.r_esp = regvalue;
#elif defined(__mips__)
regs.r_regs[PC] = regvalue;
#elif defined(__powerpc__)
regs.fixreg[1] = regvalue;
#elif defined(__riscv__)
regs.sp = regvalue;
#endif
break;
default:
DPRINTFX("ERROR: no support for reg number %d", reg);
return (-1);
}
if (ptrace(PT_SETREGS, proc_getpid(phdl), (caddr_t)®s, 0) < 0)
return (-1);
return (0);
}
int
proc_bkptdel(struct proc_handle *phdl, uintptr_t address,
unsigned long saved)
{
struct ptrace_io_desc piod;
unsigned long paddr, caddr;
if (phdl->status == PS_DEAD || phdl->status == PS_UNDEAD ||
phdl->status == PS_IDLE) {
errno = ENOENT;
return (-1);
}
DPRINTF("removing breakpoint at 0x%lx\n", address);
/*
* Overwrite the breakpoint instruction that we setup previously.
*/
caddr = address;
paddr = saved;
piod.piod_op = PIOD_WRITE_I;
piod.piod_offs = (void *)caddr;
piod.piod_addr = &paddr;
piod.piod_len = BREAKPOINT_INSTR_SZ;
if (ptrace(PT_IO, proc_getpid(phdl), (caddr_t)&piod, 0) < 0) {
DPRINTF("ERROR: couldn't write instruction at address 0x%" PRIuPTR,
address);
return (-1);
}
return (0);
}
int
proc_regget(struct proc_handle *phdl, proc_reg_t reg, unsigned long *regvalue)
{
struct reg regs;
if (phdl->status == PS_DEAD || phdl->status == PS_UNDEAD ||
phdl->status == PS_IDLE) {
errno = ENOENT;
return (-1);
}
memset(®s, 0, sizeof(regs));
if (ptrace(PT_GETREGS, proc_getpid(phdl), (caddr_t)®s, 0) < 0)
return (-1);
switch (reg) {
case REG_PC:
#if defined(__amd64__)
*regvalue = regs.r_rip;
#elif defined(__i386__)
*regvalue = regs.r_eip;
#endif
break;
case REG_SP:
#if defined(__amd64__)
*regvalue = regs.r_rsp;
#elif defined(__i386__)
*regvalue = regs.r_esp;
#endif
break;
default:
warn("ERROR: no support for reg number %d", reg);
return (-1);
}
return (0);
}
dt_proc_t *
dt_proc_lookup(dtrace_hdl_t *dtp, struct ps_prochandle *P, int remove)
{
dt_proc_hash_t *dph = dtp->dt_procs;
#if defined(sun)
pid_t pid = Pstatus(P)->pr_pid;
#else
pid_t pid = proc_getpid(P);
#endif
dt_proc_t *dpr, **dpp = &dph->dph_hash[pid & (dph->dph_hashlen - 1)];
for (dpr = *dpp; dpr != NULL; dpr = dpr->dpr_hash) {
if (dpr->dpr_pid == pid)
break;
else
dpp = &dpr->dpr_hash;
}
assert(dpr != NULL);
assert(dpr->dpr_proc == P);
if (remove)
*dpp = dpr->dpr_hash; /* remove from pid hash chain */
return (dpr);
}
int
proc_bkptset(struct proc_handle *phdl, uintptr_t address,
unsigned long *saved)
{
struct ptrace_io_desc piod;
unsigned long paddr, caddr;
*saved = 0;
if (phdl->status == PS_DEAD || phdl->status == PS_UNDEAD ||
phdl->status == PS_IDLE) {
errno = ENOENT;
return (-1);
}
/*
* Read the original instruction.
*/
caddr = address;
paddr = 0;
piod.piod_op = PIOD_READ_I;
piod.piod_offs = (void *)caddr;
piod.piod_addr = &paddr;
piod.piod_len = BREAKPOINT_INSTR_SZ;
if (ptrace(PT_IO, proc_getpid(phdl), (caddr_t)&piod, 0) < 0) {
DPRINTF("ERROR: couldn't read instruction at address 0x%" PRIuPTR,
address);
return (-1);
}
*saved = paddr;
/*
* Write a breakpoint instruction to that address.
*/
caddr = address;
paddr = BREAKPOINT_INSTR;
piod.piod_op = PIOD_WRITE_I;
piod.piod_offs = (void *)caddr;
piod.piod_addr = &paddr;
piod.piod_len = BREAKPOINT_INSTR_SZ;
if (ptrace(PT_IO, proc_getpid(phdl), (caddr_t)&piod, 0) < 0) {
warn("ERROR: couldn't write instruction at address 0x%" PRIuPTR,
address);
return (-1);
}
return (0);
}
static int
proc_stop(struct proc_handle *phdl)
{
int status;
if (kill(proc_getpid(phdl), SIGSTOP) == -1) {
DPRINTF("kill %d", proc_getpid(phdl));
return (-1);
} else if (waitpid(proc_getpid(phdl), &status, WSTOPPED) == -1) {
DPRINTF("waitpid %d", proc_getpid(phdl));
return (-1);
} else if (!WIFSTOPPED(status)) {
DPRINTFX("waitpid: unexpected status 0x%x", status);
return (-1);
}
return (0);
}
static int
dt_pid_has_jump_table(struct ps_prochandle *P, dtrace_hdl_t *dtp,
uint8_t *text, fasttrap_probe_spec_t *ftp, const GElf_Sym *symp)
{
ulong_t i;
int size;
#if defined(sun)
pid_t pid = Pstatus(P)->pr_pid;
char dmodel = Pstatus(P)->pr_dmodel;
#else
pid_t pid = proc_getpid(P);
#if __i386__
char dmodel = PR_MODEL_ILP32;
#elif __amd64__
char dmodel = PR_MODEL_LP64;
#endif
#endif
/*
* Take a pass through the function looking for a register-dependant
* jmp instruction. This could be a jump table so we have to be
* ultra conservative.
*/
for (i = 0; i < ftp->ftps_size; i += size) {
size = dt_instr_size(&text[i], dtp, pid, symp->st_value + i,
dmodel);
/*
* Assume the worst if we hit an illegal instruction.
*/
if (size <= 0) {
dt_dprintf("error at %#lx (assuming jump table)\n", i);
return (1);
}
#ifdef notyet
/*
* Register-dependant jmp instructions start with a 0xff byte
* and have the modrm.reg field set to 4. They can have an
* optional REX prefix on the 64-bit ISA.
*/
if ((text[i] == 0xff && DT_MODRM_REG(text[i + 1]) == 4) ||
(dmodel == PR_MODEL_LP64 && (text[i] & 0xf0) == 0x40 &&
text[i + 1] == 0xff && DT_MODRM_REG(text[i + 2]) == 4)) {
dt_dprintf("found a suspected jump table at %s:%lx\n",
ftp->ftps_func, i);
return (1);
}
#endif
}
return (0);
}
struct ps_prochandle *
dtrace_proc_create(dtrace_hdl_t *dtp, const char *file, char *const *argv)
{
dt_ident_t *idp = dt_idhash_lookup(dtp->dt_macros, "target");
struct ps_prochandle *P = dt_proc_create(dtp, file, argv);
if (P != NULL && idp != NULL && idp->di_id == 0)
#if defined(sun)
idp->di_id = Pstatus(P)->pr_pid; /* $target = created pid */
#else
idp->di_id = proc_getpid(P); /* $target = created pid */
#endif
return (P);
}
prmap_t *
proc_name2map(struct proc_handle *p, const char *name)
{
size_t i;
int cnt;
prmap_t *map;
char tmppath[MAXPATHLEN];
struct kinfo_vmentry *kves, *kve;
rd_loadobj_t *rdl;
/*
* If we haven't iterated over the list of loaded objects,
* librtld_db isn't yet initialized and it's very likely
* that librtld_db called us. We need to do the heavy
* lifting here to find the symbol librtld_db is looking for.
*/
if (p->nobjs == 0) {
if ((kves = kinfo_getvmmap(proc_getpid(p), &cnt)) == NULL)
return (NULL);
for (i = 0; i < (size_t)cnt; i++) {
kve = kves + i;
basename_r(kve->kve_path, tmppath);
if (strcmp(tmppath, name) == 0) {
map = proc_addr2map(p, kve->kve_start);
free(kves);
return (map);
}
}
free(kves);
return (NULL);
}
if (name == NULL || strcmp(name, "a.out") == 0) {
map = proc_addr2map(p, p->rdobjs[0].rdl_saddr);
return (map);
}
for (i = 0; i < p->nobjs; i++) {
rdl = &p->rdobjs[i];
basename_r(rdl->rdl_path, tmppath);
if (strcmp(tmppath, name) == 0) {
if ((map = malloc(sizeof(*map))) == NULL)
return (NULL);
proc_rdl2prmap(rdl, map);
return (map);
}
}
return (NULL);
}
int
proc_bkptdel(struct proc_handle *phdl, uintptr_t address,
unsigned long saved)
{
struct ptrace_io_desc piod;
uintptr_t caddr;
int ret = 0, stopped;
instr_t instr;
if (phdl->status == PS_DEAD || phdl->status == PS_UNDEAD ||
phdl->status == PS_IDLE) {
errno = ENOENT;
return (-1);
}
DPRINTFX("removing breakpoint at 0x%lx", address);
stopped = 0;
if (phdl->status != PS_STOP) {
if (proc_stop(phdl) != 0)
return (-1);
stopped = 1;
}
/*
* Overwrite the breakpoint instruction that we setup previously.
*/
caddr = address;
instr = saved;
piod.piod_op = PIOD_WRITE_I;
piod.piod_offs = (void *)caddr;
piod.piod_addr = &instr;
piod.piod_len = BREAKPOINT_INSTR_SZ;
if (ptrace(PT_IO, proc_getpid(phdl), (caddr_t)&piod, 0) < 0) {
DPRINTF("ERROR: couldn't write instruction at address 0x%"
PRIuPTR, address);
ret = -1;
}
if (stopped)
/* Restart the process if we had to stop it. */
proc_continue(phdl);
return (ret);
}
/*
* Step over the breakpoint.
*/
int
proc_bkptexec(struct proc_handle *phdl, unsigned long saved)
{
unsigned long pc;
unsigned long samesaved;
int status;
if (proc_regget(phdl, REG_PC, &pc) < 0) {
warn("ERROR: couldn't get PC register");
return (-1);
}
proc_bkptregadj(&pc);
if (proc_bkptdel(phdl, pc, saved) < 0) {
warn("ERROR: couldn't delete breakpoint");
return (-1);
}
/*
* Go back in time and step over the new instruction just
* set up by proc_bkptdel().
*/
proc_regset(phdl, REG_PC, pc);
if (ptrace(PT_STEP, proc_getpid(phdl), (caddr_t)1, 0) < 0) {
warn("ERROR: ptrace step failed");
return (-1);
}
proc_wstatus(phdl);
status = proc_getwstat(phdl);
if (!WIFSTOPPED(status)) {
warn("ERROR: don't know why process stopped");
return (-1);
}
/*
* Restore the breakpoint. The saved instruction should be
* the same as the one that we were passed in.
*/
if (proc_bkptset(phdl, pc, &samesaved) < 0) {
warn("ERROR: couldn't restore breakpoint");
return (-1);
}
assert(samesaved == saved);
return (0);
}
static int
dt_pid_create_usdt_probes(dtrace_probedesc_t *pdp, dtrace_hdl_t *dtp,
dt_pcb_t *pcb, dt_proc_t *dpr)
{
struct ps_prochandle *P = dpr->dpr_proc;
int ret = 0;
assert(DT_MUTEX_HELD(&dpr->dpr_lock));
#if defined(sun)
(void) Pupdate_maps(P);
if (Pobject_iter(P, dt_pid_usdt_mapping, P) != 0) {
ret = -1;
(void) dt_pid_error(dtp, pcb, dpr, NULL, D_PROC_USDT,
"failed to instantiate probes for pid %d: %s",
#if defined(sun)
(int)Pstatus(P)->pr_pid, strerror(errno));
#else
(int)proc_getpid(P), strerror(errno));
#endif
}
/*ARGSUSED*/
int
dt_pid_create_return_probe(struct ps_prochandle *P, dtrace_hdl_t *dtp,
fasttrap_probe_spec_t *ftp, const GElf_Sym *symp, uint64_t *stret)
{
uint8_t *text;
ulong_t i, end;
int size;
#if defined(sun)
pid_t pid = Pstatus(P)->pr_pid;
char dmodel = Pstatus(P)->pr_dmodel;
#else
pid_t pid = proc_getpid(P);
#if __i386__
char dmodel = PR_MODEL_ILP32;
#elif __amd64__
char dmodel = PR_MODEL_LP64;
#endif
#endif
/*
* We allocate a few extra bytes at the end so we don't have to check
* for overrunning the buffer.
*/
if ((text = calloc(1, symp->st_size + 4)) == NULL) {
dt_dprintf("mr sparkle: malloc() failed\n");
return (DT_PROC_ERR);
}
if (Pread(P, text, symp->st_size, symp->st_value) != symp->st_size) {
dt_dprintf("mr sparkle: Pread() failed\n");
free(text);
return (DT_PROC_ERR);
}
ftp->ftps_type = DTFTP_RETURN;
ftp->ftps_pc = (uintptr_t)symp->st_value;
ftp->ftps_size = (size_t)symp->st_size;
ftp->ftps_noffs = 0;
/*
* If there's a jump table in the function we're only willing to
* instrument these specific (and equivalent) instruction sequences:
* leave
* [rep] ret
* and
* movl %ebp,%esp
* popl %ebp
* [rep] ret
*
* We do this to avoid accidentally interpreting jump table
* offsets as actual instructions.
*/
if (dt_pid_has_jump_table(P, dtp, text, ftp, symp)) {
for (i = 0, end = ftp->ftps_size; i < end; i += size) {
size = dt_instr_size(&text[i], dtp, pid,
symp->st_value + i, dmodel);
/* bail if we hit an invalid opcode */
if (size <= 0)
break;
if (text[i] == DT_LEAVE && text[i + 1] == DT_RET) {
dt_dprintf("leave/ret at %lx\n", i + 1);
ftp->ftps_offs[ftp->ftps_noffs++] = i + 1;
size = 2;
} else if (text[i] == DT_LEAVE &&
text[i + 1] == DT_REP && text[i + 2] == DT_RET) {
dt_dprintf("leave/rep ret at %lx\n", i + 1);
ftp->ftps_offs[ftp->ftps_noffs++] = i + 1;
size = 3;
} else if (*(uint16_t *)&text[i] == DT_MOVL_EBP_ESP &&
text[i + 2] == DT_POPL_EBP &&
text[i + 3] == DT_RET) {
dt_dprintf("movl/popl/ret at %lx\n", i + 3);
ftp->ftps_offs[ftp->ftps_noffs++] = i + 3;
size = 4;
} else if (*(uint16_t *)&text[i] == DT_MOVL_EBP_ESP &&
text[i + 2] == DT_POPL_EBP &&
text[i + 3] == DT_REP &&
text[i + 4] == DT_RET) {
dt_dprintf("movl/popl/rep ret at %lx\n", i + 3);
ftp->ftps_offs[ftp->ftps_noffs++] = i + 3;
size = 5;
}
}
} else {
for (i = 0, end = ftp->ftps_size; i < end; i += size) {
size = dt_instr_size(&text[i], dtp, pid,
symp->st_value + i, dmodel);
/* bail if we hit an invalid opcode */
if (size <= 0)
break;
/* ordinary ret */
if (size == 1 && text[i] == DT_RET)
goto is_ret;
/* two-byte ret */
if (size == 2 && text[i] == DT_REP &&
text[i + 1] == DT_RET)
goto is_ret;
/* ret <imm16> */
if (size == 3 && text[i] == DT_RET16)
goto is_ret;
/* two-byte ret <imm16> */
if (size == 4 && text[i] == DT_REP &&
text[i + 1] == DT_RET16)
goto is_ret;
/* 32-bit displacement jmp outside of the function */
if (size == 5 && text[i] == DT_JMP32 && symp->st_size <=
(uintptr_t)(i + size + *(int32_t *)&text[i + 1]))
goto is_ret;
/* 8-bit displacement jmp outside of the function */
if (size == 2 && text[i] == DT_JMP8 && symp->st_size <=
(uintptr_t)(i + size + *(int8_t *)&text[i + 1]))
goto is_ret;
/* 32-bit disp. conditional jmp outside of the func. */
if (size == 6 && DT_ISJ32(*(uint16_t *)&text[i]) &&
symp->st_size <=
(uintptr_t)(i + size + *(int32_t *)&text[i + 2]))
goto is_ret;
/* 8-bit disp. conditional jmp outside of the func. */
if (size == 2 && DT_ISJ8(text[i]) && symp->st_size <=
(uintptr_t)(i + size + *(int8_t *)&text[i + 1]))
goto is_ret;
continue;
is_ret:
dt_dprintf("return at offset %lx\n", i);
ftp->ftps_offs[ftp->ftps_noffs++] = i;
}
}
free(text);
if (ftp->ftps_noffs > 0) {
if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
strerror(errno));
return (dt_set_errno(dtp, errno));
}
}
return (ftp->ftps_noffs);
}
/*ARGSUSED*/
static void
prochandler(struct ps_prochandle *P, const char *msg, void *arg)
{
#if defined(sun)
const psinfo_t *prp = Ppsinfo(P);
int pid = Pstatus(P)->pr_pid;
char name[SIG2STR_MAX];
#else
int wstatus = proc_getwstat(P);
int pid = proc_getpid(P);
#endif
if (msg != NULL) {
notice("pid %d: %s\n", pid, msg);
return;
}
#if defined(sun)
switch (Pstate(P)) {
#else
switch (proc_state(P)) {
#endif
case PS_UNDEAD:
#if defined(sun)
/*
* Ideally we would like to always report pr_wstat here, but it
* isn't possible given current /proc semantics. If we grabbed
* the process, Ppsinfo() will either fail or return a zeroed
* psinfo_t depending on how far the parent is in reaping it.
* When /proc provides a stable pr_wstat in the status file,
* this code can be improved by examining this new pr_wstat.
*/
if (prp != NULL && WIFSIGNALED(prp->pr_wstat)) {
notice("pid %d terminated by %s\n", pid,
proc_signame(WTERMSIG(prp->pr_wstat),
name, sizeof (name)));
#else
if (WIFSIGNALED(wstatus)) {
notice("pid %d terminated by %d\n", pid,
WTERMSIG(wstatus));
#endif
#if defined(sun)
} else if (prp != NULL && WEXITSTATUS(prp->pr_wstat) != 0) {
notice("pid %d exited with status %d\n",
pid, WEXITSTATUS(prp->pr_wstat));
#else
} else if (WEXITSTATUS(wstatus) != 0) {
notice("pid %d exited with status %d\n",
pid, WEXITSTATUS(wstatus));
#endif
} else {
notice("pid %d has exited\n", pid);
}
g_pslive--;
break;
case PS_LOST:
notice("pid %d exec'd a set-id or unobservable program\n", pid);
g_pslive--;
break;
}
}
/*ARGSUSED*/
static int
errhandler(const dtrace_errdata_t *data, void *arg)
{
error(data->dteda_msg);
return (DTRACE_HANDLE_OK);
}
/*ARGSUSED*/
static int
drophandler(const dtrace_dropdata_t *data, void *arg)
{
error(data->dtdda_msg);
return (DTRACE_HANDLE_OK);
}
/*ARGSUSED*/
int
dt_pid_create_glob_offset_probes(struct ps_prochandle *P, dtrace_hdl_t *dtp,
fasttrap_probe_spec_t *ftp, const GElf_Sym *symp, const char *pattern)
{
uint8_t *text;
int size;
ulong_t i, end = symp->st_size;
#if defined(sun)
pid_t pid = Pstatus(P)->pr_pid;
char dmodel = Pstatus(P)->pr_dmodel;
#else
pid_t pid = proc_getpid(P);
#if __i386__
char dmodel = PR_MODEL_ILP32;
#elif __amd64__
char dmodel = PR_MODEL_LP64;
#endif
#endif
ftp->ftps_type = DTFTP_OFFSETS;
ftp->ftps_pc = (uintptr_t)symp->st_value;
ftp->ftps_size = (size_t)symp->st_size;
ftp->ftps_noffs = 0;
if ((text = malloc(symp->st_size)) == NULL) {
dt_dprintf("mr sparkle: malloc() failed\n");
return (DT_PROC_ERR);
}
if (Pread(P, text, symp->st_size, symp->st_value) != symp->st_size) {
dt_dprintf("mr sparkle: Pread() failed\n");
free(text);
return (DT_PROC_ERR);
}
/*
* We can't instrument offsets in functions with jump tables as
* we might interpret a jump table offset as an instruction.
*/
if (dt_pid_has_jump_table(P, dtp, text, ftp, symp)) {
free(text);
return (0);
}
if (strcmp("*", pattern) == 0) {
for (i = 0; i < end; i += size) {
ftp->ftps_offs[ftp->ftps_noffs++] = i;
size = dt_instr_size(&text[i], dtp, pid,
symp->st_value + i, dmodel);
/* bail if we hit an invalid opcode */
if (size <= 0)
break;
}
} else {
char name[sizeof (i) * 2 + 1];
for (i = 0; i < end; i += size) {
(void) snprintf(name, sizeof (name), "%lx", i);
if (gmatch(name, pattern))
ftp->ftps_offs[ftp->ftps_noffs++] = i;
size = dt_instr_size(&text[i], dtp, pid,
symp->st_value + i, dmodel);
/* bail if we hit an invalid opcode */
if (size <= 0)
break;
}
}
free(text);
if (ftp->ftps_noffs > 0) {
if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
strerror(errno));
return (dt_set_errno(dtp, errno));
}
}
return (ftp->ftps_noffs);
}
/*
* Main loop for all victim process control threads. We initialize all the
* appropriate /proc control mechanisms, and then enter a loop waiting for
* the process to stop on an event or die. We process any events by calling
* appropriate subroutines, and exit when the victim dies or we lose control.
*
* The control thread synchronizes the use of dpr_proc with other libdtrace
* threads using dpr_lock. We hold the lock for all of our operations except
* waiting while the process is running: this is accomplished by writing a
* PCWSTOP directive directly to the underlying /proc/<pid>/ctl file. If the
* libdtrace client wishes to exit or abort our wait, SIGCANCEL can be used.
*/
static void *
dt_proc_control(void *arg)
{
dt_proc_control_data_t *datap = arg;
dtrace_hdl_t *dtp = datap->dpcd_hdl;
dt_proc_t *dpr = datap->dpcd_proc;
dt_proc_hash_t *dph = dpr->dpr_hdl->dt_procs;
struct ps_prochandle *P = dpr->dpr_proc;
#if defined(sun)
int pfd = Pctlfd(P);
const long wstop = PCWSTOP;
#endif
int notify = B_FALSE;
/*
* We disable the POSIX thread cancellation mechanism so that the
* client program using libdtrace can't accidentally cancel our thread.
* dt_proc_destroy() uses SIGCANCEL explicitly to simply poke us out
* of PCWSTOP with EINTR, at which point we will see dpr_quit and exit.
*/
(void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
dpr->dpr_pid = proc_getpid(P);
int pid = dpr->dpr_pid;
/*
* Set up the corresponding process for tracing by libdtrace. We want
* to be able to catch breakpoints and efficiently single-step over
* them, and we need to enable librtld_db to watch libdl activity.
*/
do_ptrace(__func__, PTRACE_ATTACH, dpr->dpr_pid, 0, 0);
(void) pthread_mutex_lock(&dpr->dpr_lock);
(void) Punsetflags(P, PR_ASYNC); /* require synchronous mode */
(void) Psetflags(P, PR_BPTADJ); /* always adjust eip on x86 */
(void) Punsetflags(P, PR_FORK); /* do not inherit on fork */
(void) Pfault(P, FLTBPT, B_TRUE); /* always trace breakpoints */
(void) Pfault(P, FLTTRACE, B_TRUE); /* always trace single-step */
/*
* We must trace exit from exec() system calls so that if the exec is
* successful, we can reset our breakpoints and re-initialize libproc.
*/
(void) Psysexit(P, SYS_exec, B_TRUE);
(void) Psysexit(P, SYS_execve, B_TRUE);
/*
* We must trace entry and exit for fork() system calls in order to
* disable our breakpoints temporarily during the fork. We do not set
* the PR_FORK flag, so if fork succeeds the child begins executing and
* does not inherit any other tracing behaviors or a control thread.
*/
(void) Psysentry(P, SYS_vfork, B_TRUE);
(void) Psysexit(P, SYS_vfork, B_TRUE);
(void) Psysentry(P, SYS_fork1, B_TRUE);
(void) Psysexit(P, SYS_fork1, B_TRUE);
(void) Psysentry(P, SYS_forkall, B_TRUE);
(void) Psysexit(P, SYS_forkall, B_TRUE);
(void) Psysentry(P, SYS_forksys, B_TRUE);
(void) Psysexit(P, SYS_forksys, B_TRUE);
Psync(P); /* enable all /proc changes */
dt_proc_attach(dpr, B_FALSE); /* enable rtld breakpoints */
/*
* If PR_KLC is set, we created the process; otherwise we grabbed it.
* Check for an appropriate stop request and wait for dt_proc_continue.
*/
dpr->dpr_stop |= DT_PROC_STOP_CREATE;
if (Pstatus(P)->pr_flags & PR_KLC)
dt_proc_stop(dpr, DT_PROC_STOP_CREATE);
else
dt_proc_stop(dpr, DT_PROC_STOP_GRAB);
if (Psetrun(P, 0, 0) == -1) {
dt_dprintf("pid %d: failed to set running: %s\n",
(int)dpr->dpr_pid, strerror(errno));
}
(void) pthread_mutex_unlock(&dpr->dpr_lock);
/*
* Wait for the process corresponding to this control thread to stop,
* process the event, and then set it running again. We want to sleep
* with dpr_lock *unheld* so that other parts of libdtrace can use the
* ps_prochandle in the meantime (e.g. ustack()). To do this, we write
* a PCWSTOP directive directly to the underlying /proc/<pid>/ctl file.
* Once the process stops, we wake up, grab dpr_lock, and then call
* Pwait() (which will return immediately) and do our processing.
*/
//printf("%s: waiting to quit\n", __func__);
while (!dpr->dpr_quit) {
const lwpstatus_t *psp;
#if defined(sun)
if (write(pfd, &wstop, sizeof (wstop)) == -1 && errno == EINTR)
continue; /* check dpr_quit and continue waiting */
#else
/* Wait for the process to report status. */
proc_wait(P);
#endif
(void) pthread_mutex_lock(&dpr->dpr_lock);
pwait_locked:
if (Pstopstatus(P, PCNULL, 0) == -1 && errno == EINTR) {
//printf("%s stopstatus (loop) pr_pid pid=%d\n", __func__, Pstatus(dpr->dpr_proc)->pr_pid);
(void) pthread_mutex_unlock(&dpr->dpr_lock);
continue; /* check dpr_quit and continue waiting */
}
switch (Pstate(P)) {
case PS_STOP:
psp = &Pstatus(P)->pr_lwp;
dt_dprintf("pid %d: proc stopped showing %d/%d\n",
pid, psp->pr_why, psp->pr_what);
#if defined(sun)
/*
* If the process stops showing PR_REQUESTED, then the
* DTrace stop() action was applied to it or another
* debugging utility (e.g. pstop(1)) asked it to stop.
* In either case, the user's intention is for the
* process to remain stopped until another external
* mechanism (e.g. prun(1)) is applied. So instead of
* setting the process running ourself, we wait for
* someone else to do so. Once that happens, we return
* to our normal loop waiting for an event of interest.
*/
if (psp->pr_why == PR_REQUESTED) {
dt_proc_waitrun(dpr);
(void) pthread_mutex_unlock(&dpr->dpr_lock);
continue;
}
/*
* If the process stops showing one of the events that
* we are tracing, perform the appropriate response.
* Note that we ignore PR_SUSPENDED, PR_CHECKPOINT, and
* PR_JOBCONTROL by design: if one of these conditions
* occurs, we will fall through to Psetrun() but the
* process will remain stopped in the kernel by the
* corresponding mechanism (e.g. job control stop).
*/
if (psp->pr_why == PR_FAULTED && psp->pr_what == FLTBPT)
dt_proc_bpmatch(dtp, dpr);
else if (psp->pr_why == PR_SYSENTRY &&
IS_SYS_FORK(psp->pr_what))
dt_proc_bpdisable(dpr);
else if (psp->pr_why == PR_SYSEXIT &&
IS_SYS_FORK(psp->pr_what))
dt_proc_bpenable(dpr);
else if (psp->pr_why == PR_SYSEXIT &&
IS_SYS_EXEC(psp->pr_what))
dt_proc_attach(dpr, B_TRUE);
#endif
//printf("In PS_STOP dpr_stop=%x\n", dpr->dpr_stop);
break;
case PS_LOST:
//printf("in PS_LOST\n");
if (Preopen(P) == 0)
goto pwait_locked;
dt_dprintf("pid %d: proc lost: %s\n",
pid, strerror(errno));
dpr->dpr_quit = B_TRUE;
notify = B_TRUE;
break;
case PS_UNDEAD:
case PS_DEAD:
dt_dprintf("pid %d: proc died\n", pid);
dpr->dpr_quit = B_TRUE;
notify = B_TRUE;
break;
}
if (Pstate(P) != PS_UNDEAD && Psetrun(P, 0, 0) == -1) {
dt_dprintf("pid %d: failed to set running: %s\n",
(int)dpr->dpr_pid, strerror(errno));
}
(void) pthread_mutex_unlock(&dpr->dpr_lock);
}
/*
* If the control thread detected PS_UNDEAD or PS_LOST, then enqueue
* the dt_proc_t structure on the dt_proc_hash_t notification list.
*/
if (notify)
dt_proc_notify(dtp, dph, dpr, NULL);
/*
* Destroy and remove any remaining breakpoints, set dpr_done and clear
* dpr_tid to indicate the control thread has exited, and notify any
* waiting thread in dt_proc_destroy() that we have succesfully exited.
*/
(void) pthread_mutex_lock(&dpr->dpr_lock);
dt_proc_bpdestroy(dpr, B_TRUE);
dpr->dpr_done = B_TRUE;
dpr->dpr_tid = 0;
(void) pthread_cond_broadcast(&dpr->dpr_cv);
(void) pthread_mutex_unlock(&dpr->dpr_lock);
return (NULL);
}
static void
proc_cont(struct proc_handle *phdl)
{
ptrace(PT_CONTINUE, proc_getpid(phdl), (caddr_t)1, 0);
}
static int
dt_pid_per_sym(dt_pid_probe_t *pp, const GElf_Sym *symp, const char *func)
{
dtrace_hdl_t *dtp = pp->dpp_dtp;
dt_pcb_t *pcb = pp->dpp_pcb;
dt_proc_t *dpr = pp->dpp_dpr;
fasttrap_probe_spec_t *ftp;
uint64_t off;
char *end;
uint_t nmatches = 0;
ulong_t sz;
int glob, err;
int isdash = strcmp("-", func) == 0;
pid_t pid;
#if defined(sun)
pid = Pstatus(pp->dpp_pr)->pr_pid;
#else
pid = proc_getpid(pp->dpp_pr);
#endif
dt_dprintf("creating probe pid%d:%s:%s:%s\n", (int)pid, pp->dpp_obj,
func, pp->dpp_name);
sz = sizeof (fasttrap_probe_spec_t) + (isdash ? 4 :
(symp->st_size - 1) * sizeof (ftp->ftps_offs[0]));
if ((ftp = dt_alloc(dtp, sz)) == NULL) {
dt_dprintf("proc_per_sym: dt_alloc(%lu) failed\n", sz);
return (1); /* errno is set for us */
}
ftp->ftps_pid = pid;
(void) strncpy(ftp->ftps_func, func, sizeof (ftp->ftps_func));
dt_pid_objname(ftp->ftps_mod, sizeof (ftp->ftps_mod), pp->dpp_lmid,
pp->dpp_obj);
if (!isdash && gmatch("return", pp->dpp_name)) {
if (dt_pid_create_return_probe(pp->dpp_pr, dtp, ftp, symp,
pp->dpp_stret) < 0) {
return (dt_pid_error(dtp, pcb, dpr, ftp,
D_PROC_CREATEFAIL, "failed to create return probe "
"for '%s': %s", func,
dtrace_errmsg(dtp, dtrace_errno(dtp))));
}
nmatches++;
}
if (!isdash && gmatch("entry", pp->dpp_name)) {
if (dt_pid_create_entry_probe(pp->dpp_pr, dtp, ftp, symp) < 0) {
return (dt_pid_error(dtp, pcb, dpr, ftp,
D_PROC_CREATEFAIL, "failed to create entry probe "
"for '%s': %s", func,
dtrace_errmsg(dtp, dtrace_errno(dtp))));
}
nmatches++;
}
glob = strisglob(pp->dpp_name);
if (!glob && nmatches == 0) {
off = strtoull(pp->dpp_name, &end, 16);
if (*end != '\0') {
return (dt_pid_error(dtp, pcb, dpr, ftp, D_PROC_NAME,
"'%s' is an invalid probe name", pp->dpp_name));
}
if (off >= symp->st_size) {
return (dt_pid_error(dtp, pcb, dpr, ftp, D_PROC_OFF,
"offset 0x%llx outside of function '%s'",
(u_longlong_t)off, func));
}
err = dt_pid_create_offset_probe(pp->dpp_pr, pp->dpp_dtp, ftp,
symp, off);
if (err == DT_PROC_ERR) {
return (dt_pid_error(dtp, pcb, dpr, ftp,
D_PROC_CREATEFAIL, "failed to create probe at "
"'%s+0x%llx': %s", func, (u_longlong_t)off,
dtrace_errmsg(dtp, dtrace_errno(dtp))));
}
if (err == DT_PROC_ALIGN) {
return (dt_pid_error(dtp, pcb, dpr, ftp, D_PROC_ALIGN,
"offset 0x%llx is not aligned on an instruction",
(u_longlong_t)off));
}
nmatches++;
} else if (glob && !isdash) {
if (dt_pid_create_glob_offset_probes(pp->dpp_pr,
pp->dpp_dtp, ftp, symp, pp->dpp_name) < 0) {
return (dt_pid_error(dtp, pcb, dpr, ftp,
D_PROC_CREATEFAIL,
"failed to create offset probes in '%s': %s", func,
dtrace_errmsg(dtp, dtrace_errno(dtp))));
}
nmatches++;
}
pp->dpp_nmatches += nmatches;
dt_free(dtp, ftp);
return (0);
}
/*ARGSUSED*/
int
dt_pid_create_offset_probe(struct ps_prochandle *P, dtrace_hdl_t *dtp,
fasttrap_probe_spec_t *ftp, const GElf_Sym *symp, ulong_t off)
{
ftp->ftps_type = DTFTP_OFFSETS;
ftp->ftps_pc = (uintptr_t)symp->st_value;
ftp->ftps_size = (size_t)symp->st_size;
ftp->ftps_noffs = 1;
if (strcmp("-", ftp->ftps_func) == 0) {
ftp->ftps_offs[0] = off;
} else {
uint8_t *text;
ulong_t i;
int size;
#if defined(sun)
pid_t pid = Pstatus(P)->pr_pid;
char dmodel = Pstatus(P)->pr_dmodel;
#else
pid_t pid = proc_getpid(P);
#if __i386__
char dmodel = PR_MODEL_ILP32;
#elif __amd64__
char dmodel = PR_MODEL_LP64;
#endif
#endif
if ((text = malloc(symp->st_size)) == NULL) {
dt_dprintf("mr sparkle: malloc() failed\n");
return (DT_PROC_ERR);
}
if (Pread(P, text, symp->st_size, symp->st_value) !=
symp->st_size) {
dt_dprintf("mr sparkle: Pread() failed\n");
free(text);
return (DT_PROC_ERR);
}
/*
* We can't instrument offsets in functions with jump tables
* as we might interpret a jump table offset as an
* instruction.
*/
if (dt_pid_has_jump_table(P, dtp, text, ftp, symp)) {
free(text);
return (0);
}
for (i = 0; i < symp->st_size; i += size) {
if (i == off) {
ftp->ftps_offs[0] = i;
break;
}
/*
* If we've passed the desired offset without a
* match, then the given offset must not lie on a
* instruction boundary.
*/
if (i > off) {
free(text);
return (DT_PROC_ALIGN);
}
size = dt_instr_size(&text[i], dtp, pid,
symp->st_value + i, dmodel);
/*
* If we hit an invalid instruction, bail as if we
* couldn't find the offset.
*/
if (size <= 0) {
free(text);
return (DT_PROC_ALIGN);
}
}
free(text);
}
if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
strerror(errno));
return (dt_set_errno(dtp, errno));
}
return (ftp->ftps_noffs);
}
