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o Add support for COMPAT_IA32.

Browse Source 
o  Incorporate review comments:
   -  Properly reference and lock the map
   -  Take into account that the VM map can change inbetween requests
   -  Add the fileid and fsid attributes

Credits: kib@
Reviewed by: kib@
This commit is contained in:
Marcel Moolenaar 2010-02-11 18:00:53 +00:00
parent f634c39527
commit 162110273c
3 changed files with 151 additions and 86 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
lib/libc/sys/ptrace.2
View File

@ -2,7 +2,7 @@
.\" $NetBSD: ptrace.2,v 1.2 1995/02/27 12:35:37 cgd Exp $
.\"
.\" This file is in the public domain.
.Dd February 8, 2010
.Dd February 11, 2010
.Dt PTRACE 2
.Os
.Sh NAME
@ -343,23 +343,30 @@ argument specifies a pointer to a
which is defined as follows:
.Bd -literal
struct ptrace_vm_entry {
void *pve_cookie;
u_long pve_start;
u_long pve_end;
u_long pve_offset;
u_int pve_prot;
u_int pve_pathlen;
char *pve_path;
int pve_entry;
int pve_timestamp;
u_long pve_start;
u_long pve_end;
u_long pve_offset;
u_int pve_prot;
u_int pve_pathlen;
long pve_fileid;
uint32_t pve_fsid;
char *pve_path;
};
.Ed
.Pp
The first entry is returned by setting
.Va pve_cookie
to
.Dv NULL .
.Va pve_entry
to zero.
Subsequent entries are returned by leaving
.Va pve_cookie
.Va pve_entry
unmodified from the value returned by previous requests.
The
.Va pve_timestamp
field can be used to detect changes to the VM map while iterating over the
entries.
The tracing process can then take appropriate action, such as restarting.
By setting
.Va pve_pathlen
to a non-zero value on entry, the pathname of the backing object is returned
@ -434,7 +441,8 @@ was attempted on a process with no valid register set.
.It
.Dv PT_VM_ENTRY
was given an invalid value for
.Fa pve_cookie .
.Fa pve_entry .
This can also be caused by changes to the VM map of the process.
.El
.It Bq Er EBUSY
.Bl -bullet -compact

186
sys/kern/sys_process.c
View File

@ -75,12 +75,15 @@ struct ptrace_io_desc32 {
};
struct ptrace_vm_entry32 {
uint32_t pve_cookie;
int pve_entry;
int pve_timestamp;
uint32_t pve_start;
uint32_t pve_end;
uint32_t pve_offset;
u_int pve_prot;
u_int pve_pathlen;
int32_t pve_fileid;
u_int pve_fsid;
uint32_t pve_path;
};
@ -360,89 +363,142 @@ proc_rwmem(struct proc *p, struct uio *uio)
static int
ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
{
struct vattr vattr;
vm_map_t map;
vm_map_entry_t entry;
vm_object_t obj, tobj, lobj;
struct vmspace *vm;
struct vnode *vp;
char *freepath, *fullpath;
u_int pathlen;
int error, vfslocked;
int error, index, vfslocked;
map = &p->p_vmspace->vm_map;
entry = map->header.next;
if (pve->pve_cookie != NULL) {
while (entry != &map->header && entry != pve->pve_cookie)
error = 0;
obj = NULL;
vm = vmspace_acquire_ref(p);
map = &vm->vm_map;
vm_map_lock_read(map);
do {
entry = map->header.next;
index = 0;
while (index < pve->pve_entry && entry != &map->header) {
entry = entry->next;
if (entry != pve->pve_cookie)
return (EINVAL);
entry = entry->next;
}
while (entry != &map->header && (entry->eflags & MAP_ENTRY_IS_SUB_MAP))
entry = entry->next;
if (entry == &map->header)
return (ENOENT);
index++;
}
if (index != pve->pve_entry) {
error = EINVAL;
break;
}
while (entry != &map->header &&
(entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
entry = entry->next;
index++;
}
if (entry == &map->header) {
error = ENOENT;
break;
}
/* We got an entry. */
pve->pve_cookie = entry;
pve->pve_start = entry->start;
pve->pve_end = entry->end - 1;
pve->pve_offset = entry->offset;
pve->pve_prot = entry->protection;
/* We got an entry. */
pve->pve_entry = index + 1;
pve->pve_timestamp = map->timestamp;
pve->pve_start = entry->start;
pve->pve_end = entry->end - 1;
pve->pve_offset = entry->offset;
pve->pve_prot = entry->protection;
/* Backing object's path needed? */
if (pve->pve_pathlen == 0)
return (0);
/* Backing object's path needed? */
if (pve->pve_pathlen == 0)
break;
pathlen = pve->pve_pathlen;
pve->pve_pathlen = 0;
pathlen = pve->pve_pathlen;
pve->pve_pathlen = 0;
obj = entry->object.vm_object;
if (obj == NULL)
return (0);
obj = entry->object.vm_object;
if (obj != NULL)
VM_OBJECT_LOCK(obj);
} while (0);
VM_OBJECT_LOCK(obj);
for (lobj = tobj = obj; tobj; tobj = tobj->backing_object) {
if (tobj != obj)
VM_OBJECT_LOCK(tobj);
if (lobj != obj)
VM_OBJECT_UNLOCK(lobj);
lobj = tobj;
pve->pve_offset += tobj->backing_object_offset;
}
if (lobj != NULL) {
vm_map_unlock_read(map);
vmspace_free(vm);
if (error == 0 && obj != NULL) {
lobj = obj;
for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
if (tobj != obj)
VM_OBJECT_LOCK(tobj);
if (lobj != obj)
VM_OBJECT_UNLOCK(lobj);
lobj = tobj;
pve->pve_offset += tobj->backing_object_offset;
}
vp = (lobj->type == OBJT_VNODE) ? lobj->handle : NULL;
if (vp != NULL)
vref(vp);
if (lobj != obj)
VM_OBJECT_UNLOCK(lobj);
VM_OBJECT_UNLOCK(obj);
} else
vp = NULL;
if (vp == NULL)
return (0);
if (vp != NULL) {
freepath = NULL;
fullpath = NULL;
vn_fullpath(td, vp, &fullpath, &freepath);
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
vn_lock(vp, LK_SHARED | LK_RETRY);
if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
pve->pve_fileid = vattr.va_fileid;
pve->pve_fsid = vattr.va_fsid;
}
vput(vp);
VFS_UNLOCK_GIANT(vfslocked);
freepath = NULL;
fullpath = NULL;
vn_fullpath(td, vp, &fullpath, &freepath);
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
vrele(vp);
VFS_UNLOCK_GIANT(vfslocked);
error = 0;
if (fullpath != NULL) {
pve->pve_pathlen = strlen(fullpath) + 1;
if (pve->pve_pathlen <= pathlen) {
error = copyout(fullpath, pve->pve_path,
pve->pve_pathlen);
} else
error = ENAMETOOLONG;
if (fullpath != NULL) {
pve->pve_pathlen = strlen(fullpath) + 1;
if (pve->pve_pathlen <= pathlen) {
error = copyout(fullpath, pve->pve_path,
pve->pve_pathlen);
} else
error = ENAMETOOLONG;
}
if (freepath != NULL)
free(freepath, M_TEMP);
}
}
if (freepath != NULL)
free(freepath, M_TEMP);
return (error);
}
#ifdef COMPAT_IA32
static int
ptrace_vm_entry32(struct thread *td, struct proc *p,
struct ptrace_vm_entry32 *pve32)
{
struct ptrace_vm_entry pve;
int error;
pve.pve_entry = pve32->pve_entry;
pve.pve_pathlen = pve32->pve_pathlen;
pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
error = ptrace_vm_entry(td, p, &pve);
if (error == 0) {
pve32->pve_entry = pve.pve_entry;
pve32->pve_timestamp = pve.pve_timestamp;
pve32->pve_start = pve.pve_start;
pve32->pve_end = pve.pve_end;
pve32->pve_offset = pve.pve_offset;
pve32->pve_prot = pve.pve_prot;
pve32->pve_fileid = pve.pve_fileid;
pve32->pve_fsid = pve.pve_fsid;
}
pve32->pve_pathlen = pve.pve_pathlen;
return (error);
}
#endif /* COMPAT_IA32 */
/*
* Process debugging system call.
*/
@ -1087,14 +1143,12 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
break;
case PT_VM_ENTRY:
#ifdef COMPAT_IA32
/* XXX to be implemented. */
if (wrap32) {
error = EDOOFUS;
break;
}
#endif
PROC_UNLOCK(p);
#ifdef COMPAT_IA32
if (wrap32)
error = ptrace_vm_entry32(td, p, addr);
else
#endif
error = ptrace_vm_entry(td, p, addr);
PROC_LOCK(p);
break;

17
sys/sys/ptrace.h
View File

@ -104,13 +104,16 @@ struct ptrace_lwpinfo {
/* Argument structure for PT_VM_ENTRY. */
struct ptrace_vm_entry {
void *pve_cookie; /* Token used to iterate. */
u_long pve_start; /* Start VA of range. */
u_long pve_end; /* End VA of range (incl). */
u_long pve_offset; /* Offset in backing object. */
u_int pve_prot; /* Protection of memory range. */
u_int pve_pathlen; /* Size of path. */
char *pve_path; /* Path name of object. */
int pve_entry; /* Entry number used for iteration. */
int pve_timestamp; /* Generation number of VM map. */
u_long pve_start; /* Start VA of range. */
u_long pve_end; /* End VA of range (incl). */
u_long pve_offset; /* Offset in backing object. */
u_int pve_prot; /* Protection of memory range. */
u_int pve_pathlen; /* Size of path. */
long pve_fileid; /* File ID. */
uint32_t pve_fsid; /* File system ID. */
char *pve_path; /* Path name of object. */
};
#ifdef _KERNEL