Author: markj
Date: Sat Jul 30 03:09:23 2016
New Revision: 303533
URL: https://svnweb.freebsd.org/changeset/base/303533
Log:
libproc: Add proc_getmodel().
This is used by libdtrace to determine the data model of target processes.
This allows for the creation of pid provider probes in 32-bit processes on
amd64.
MFC after: 1 month
Modified:
head/lib/libproc/Makefile
head/lib/libproc/_libproc.h
head/lib/libproc/libproc.h
head/lib/libproc/proc_create.c
head/lib/libproc/proc_rtld.c
head/lib/libproc/proc_util.c
head/share/mk/src.libnames.mk
Modified: head/lib/libproc/Makefile
==============================================================================
--- head/lib/libproc/Makefile Sat Jul 30 03:07:14 2016 (r303532)
+++ head/lib/libproc/Makefile Sat Jul 30 03:09:23 2016 (r303533)
@@ -24,7 +24,7 @@ LIBADD+= cxxrt
LIBADD+= supcplusplus
.endif
-LIBADD+= elf rtld_db util
+LIBADD+= elf procstat rtld_db util
.if ${MK_CDDL} != "no"
LIBADD+= ctf
Modified: head/lib/libproc/_libproc.h
==============================================================================
--- head/lib/libproc/_libproc.h Sat Jul 30 03:07:14 2016 (r303532)
+++ head/lib/libproc/_libproc.h Sat Jul 30 03:09:23 2016 (r303533)
@@ -33,18 +33,22 @@
#include "libproc.h"
+struct procstat;
+
struct proc_handle {
pid_t pid; /* Process ID. */
int flags; /* Process flags. */
int status; /* Process status (PS_*). */
int wstat; /* Process wait status. */
+ int model; /* Process data model. */
rd_agent_t *rdap; /* librtld_db agent */
rd_loadobj_t *rdobjs; /* Array of loaded objects. */
size_t rdobjsz; /* Array size. */
size_t nobjs; /* Num. objects currently loaded. */
rd_loadobj_t *rdexec; /* rdobj for program executable. */
struct lwpstatus lwps; /* Process status. */
- char execname[MAXPATHLEN]; /* Path to program executable. */
+ struct procstat *procstat; /* libprocstat handle. */
+ char execpath[MAXPATHLEN]; /* Path to program executable. */
};
#ifdef DEBUG
Modified: head/lib/libproc/libproc.h
==============================================================================
--- head/lib/libproc/libproc.h Sat Jul 30 03:07:14 2016 (r303532)
+++ head/lib/libproc/libproc.h Sat Jul 30 03:09:23 2016 (r303533)
@@ -113,6 +113,9 @@ typedef struct lwpstatus {
#define FLTBPT -1
} lwpstatus_t;
+#define PR_MODEL_ILP32 1
+#define PR_MODEL_LP64 2
+
/* Function prototype definitions. */
__BEGIN_DECLS
@@ -136,6 +139,7 @@ int proc_name2sym(struct proc_handle *,
struct ctf_file *proc_name2ctf(struct proc_handle *, const char *);
int proc_setflags(struct proc_handle *, int);
int proc_state(struct proc_handle *);
+int proc_getmodel(struct proc_handle *);
pid_t proc_getpid(struct proc_handle *);
int proc_wstatus(struct proc_handle *);
int proc_getwstat(struct proc_handle *);
Modified: head/lib/libproc/proc_create.c
==============================================================================
--- head/lib/libproc/proc_create.c Sat Jul 30 03:07:14 2016
(r303532)
+++ head/lib/libproc/proc_create.c Sat Jul 30 03:09:23 2016
(r303533)
@@ -28,6 +28,7 @@
#include <sys/types.h>
#include <sys/sysctl.h>
+#include <sys/user.h>
#include <sys/wait.h>
#include <err.h>
@@ -38,57 +39,103 @@
#include <string.h>
#include <unistd.h>
+#include <libelf.h>
+#include <libprocstat.h>
+
#include "_libproc.h"
-static int proc_init(pid_t, int, int, struct proc_handle *);
+static int getelfclass(int);
+static int proc_init(pid_t, int, int, struct proc_handle **);
+
+static int
+getelfclass(int fd)
+{
+ GElf_Ehdr ehdr;
+ Elf *e;
+ int class;
+
+ class = ELFCLASSNONE;
+
+ if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL)
+ goto out;
+ if (gelf_getehdr(e, &ehdr) == NULL)
+ goto out;
+ class = ehdr.e_ident[EI_CLASS];
+out:
+ (void)elf_end(e);
+ return (class);
+}
static int
-proc_init(pid_t pid, int flags, int status, struct proc_handle *phdl)
+proc_init(pid_t pid, int flags, int status, struct proc_handle **pphdl)
{
- int mib[4], error;
- size_t len;
+ struct kinfo_proc *kp;
+ struct proc_handle *phdl;
+ int error, class, count, fd;
+
+ *pphdl = NULL;
+ if ((phdl = malloc(sizeof(*phdl))) == NULL)
+ return (ENOMEM);
memset(phdl, 0, sizeof(*phdl));
phdl->pid = pid;
phdl->flags = flags;
phdl->status = status;
+ phdl->procstat = procstat_open_sysctl();
+ if (phdl->procstat == NULL)
+ return (ENOMEM);
- mib[0] = CTL_KERN;
- mib[1] = KERN_PROC;
- mib[2] = KERN_PROC_PATHNAME;
- mib[3] = pid;
- len = sizeof(phdl->execname);
- if (sysctl(mib, 4, phdl->execname, &len, NULL, 0) != 0) {
- error = errno;
- DPRINTF("ERROR: cannot get pathname for child process %d", pid);
+ /* Obtain a path to the executable. */
+ if ((kp = procstat_getprocs(phdl->procstat, KERN_PROC_PID, pid,
+ &count)) == NULL)
+ return (ENOMEM);
+ error = procstat_getpathname(phdl->procstat, kp, phdl->execpath,
+ sizeof(phdl->execpath));
+ procstat_freeprocs(phdl->procstat, kp);
+ if (error != 0)
return (error);
+
+ /* Use it to determine the data model for the process. */
+ if ((fd = open(phdl->execpath, O_RDONLY)) < 0) {
+ error = errno;
+ goto out;
}
- if (len == 0)
- phdl->execname[0] = '\0';
+ class = getelfclass(fd);
+ switch (class) {
+ case ELFCLASS64:
+ phdl->model = PR_MODEL_LP64;
+ break;
+ case ELFCLASS32:
+ phdl->model = PR_MODEL_ILP32;
+ break;
+ case ELFCLASSNONE:
+ default:
+ error = EINVAL;
+ break;
+ }
+ (void)close(fd);
- return (0);
+out:
+ *pphdl = phdl;
+ return (error);
}
int
proc_attach(pid_t pid, int flags, struct proc_handle **pphdl)
{
struct proc_handle *phdl;
- int error = 0;
- int status;
+ int error, status;
if (pid == 0 || pid == getpid())
return (EINVAL);
+ if (elf_version(EV_CURRENT) == EV_NONE)
+ return (ENOENT);
/*
* Allocate memory for the process handle, a structure containing
* all things related to the process.
*/
- if ((phdl = malloc(sizeof(struct proc_handle))) == NULL)
- return (ENOMEM);
-
- elf_version(EV_CURRENT);
-
- error = proc_init(pid, flags, PS_RUN, phdl);
+ error = proc_init(pid, flags, PS_RUN, &phdl);
if (error != 0)
goto out;
@@ -106,16 +153,17 @@ proc_attach(pid_t pid, int flags, struct
}
/* Check for an unexpected status. */
- if (WIFSTOPPED(status) == 0)
+ if (!WIFSTOPPED(status))
DPRINTFX("ERROR: child process %d status 0x%x", pid, status);
else
phdl->status = PS_STOP;
out:
- if (error)
+ if (error && phdl != NULL) {
proc_free(phdl);
- else
- *pphdl = phdl;
+ phdl = NULL;
+ }
+ *pphdl = phdl;
return (error);
}
@@ -128,14 +176,8 @@ proc_create(const char *file, char * con
int status;
pid_t pid;
- /*
- * Allocate memory for the process handle, a structure containing
- * all things related to the process.
- */
- if ((phdl = malloc(sizeof(struct proc_handle))) == NULL)
- return (ENOMEM);
-
- elf_version(EV_CURRENT);
+ if (elf_version(EV_CURRENT) == EV_NONE)
+ return (ENOENT);
/* Fork a new process. */
if ((pid = vfork()) == -1)
@@ -153,9 +195,10 @@ proc_create(const char *file, char * con
/* Couldn't execute the file. */
_exit(2);
+ /* NOTREACHED */
} else {
/* The parent owns the process handle. */
- error = proc_init(pid, 0, PS_IDLE, phdl);
+ error = proc_init(pid, 0, PS_IDLE, &phdl);
if (error != 0)
goto bad;
@@ -167,7 +210,7 @@ proc_create(const char *file, char * con
}
/* Check for an unexpected status. */
- if (WIFSTOPPED(status) == 0) {
+ if (!WIFSTOPPED(status)) {
error = errno;
DPRINTFX("ERROR: child process %d status 0x%x", pid,
status);
goto bad;
@@ -175,15 +218,19 @@ proc_create(const char *file, char * con
phdl->status = PS_STOP;
}
bad:
- if (error)
+ if (error && phdl != NULL) {
proc_free(phdl);
- else
- *pphdl = phdl;
+ phdl = NULL;
+ }
+ *pphdl = phdl;
return (error);
}
void
proc_free(struct proc_handle *phdl)
{
+
+ if (phdl->procstat != NULL)
+ procstat_close(phdl->procstat);
free(phdl);
}
Modified: head/lib/libproc/proc_rtld.c
==============================================================================
--- head/lib/libproc/proc_rtld.c Sat Jul 30 03:07:14 2016
(r303532)
+++ head/lib/libproc/proc_rtld.c Sat Jul 30 03:09:23 2016
(r303533)
@@ -49,7 +49,7 @@ map_iter(const rd_loadobj_t *lop, void *
if (phdl->rdobjs == NULL)
return (-1);
}
- if (strcmp(lop->rdl_path, phdl->execname) == 0 &&
+ if (strcmp(lop->rdl_path, phdl->execpath) == 0 &&
(lop->rdl_prot & RD_RDL_X) != 0)
phdl->rdexec = &phdl->rdobjs[phdl->nobjs];
memcpy(&phdl->rdobjs[phdl->nobjs++], lop, sizeof(*lop));
Modified: head/lib/libproc/proc_util.c
==============================================================================
--- head/lib/libproc/proc_util.c Sat Jul 30 03:07:14 2016
(r303532)
+++ head/lib/libproc/proc_util.c Sat Jul 30 03:09:23 2016
(r303533)
@@ -140,6 +140,16 @@ proc_getpid(struct proc_handle *phdl)
}
int
+proc_getmodel(struct proc_handle *phdl)
+{
+
+ if (phdl == NULL)
+ return (-1);
+
+ return (phdl->model);
+}
+
+int
proc_wstatus(struct proc_handle *phdl)
{
int status;
Modified: head/share/mk/src.libnames.mk
==============================================================================
--- head/share/mk/src.libnames.mk Sat Jul 30 03:07:14 2016
(r303532)
+++ head/share/mk/src.libnames.mk Sat Jul 30 03:09:23 2016
(r303533)
@@ -255,7 +255,7 @@ _DP_proc= supcplusplus
.if ${MK_CDDL} != "no"
_DP_proc+= ctf
.endif
-_DP_proc+= elf rtld_db util
+_DP_proc+= elf procstat rtld_db util
_DP_mp= crypto
_DP_memstat= kvm
_DP_magic= z
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