1
0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-25 11:37:56 +00:00
freebsd/sys/kern/sys_process.c

359 lines
8.9 KiB
C
Raw Normal View History

/*
* Copyright (c) 1994, Sean Eric Fagan
* All rights reserved.
1994-05-24 10:09:53 +00:00
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Sean Eric Fagan.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
1994-05-24 10:09:53 +00:00
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
1994-05-24 10:09:53 +00:00
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
1994-05-24 10:09:53 +00:00
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
1995-05-30 08:16:23 +00:00
* $Id: sys_process.c,v 1.13 1995/05/12 21:39:48 davidg Exp $
1994-05-24 10:09:53 +00:00
*/
#include <sys/param.h>
#include <sys/systm.h>
1994-05-24 10:09:53 +00:00
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/ptrace.h>
1994-05-24 10:09:53 +00:00
#include <sys/errno.h>
#include <machine/reg.h>
#include <machine/psl.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_kern.h>
#include <sys/user.h>
static int
pread (struct proc *procp, unsigned int addr, unsigned int *retval) {
int rv;
vm_map_t map, tmap;
vm_object_t object;
vm_offset_t kva = 0;
int page_offset; /* offset into page */
vm_offset_t pageno; /* page number */
vm_map_entry_t out_entry;
vm_prot_t out_prot;
boolean_t wired, single_use;
vm_offset_t off;
/* Map page into kernel space */
map = &procp->p_vmspace->vm_map;
page_offset = addr - trunc_page(addr);
pageno = trunc_page(addr);
1995-05-30 08:16:23 +00:00
tmap = map;
rv = vm_map_lookup (&tmap, pageno, VM_PROT_READ, &out_entry,
&object, &off, &out_prot, &wired, &single_use);
if (rv != KERN_SUCCESS)
return EINVAL;
1995-05-30 08:16:23 +00:00
vm_map_lookup_done (tmap, out_entry);
1995-05-30 08:16:23 +00:00
/* Find space in kernel_map for the page we're interested in */
rv = vm_map_find (kernel_map, object, off, &kva, PAGE_SIZE, 1);
if (!rv) {
vm_object_reference (object);
rv = vm_map_pageable (kernel_map, kva, kva + PAGE_SIZE, 0);
if (!rv) {
*retval = 0;
bcopy ((caddr_t)kva + page_offset,
retval, sizeof *retval);
}
vm_map_remove (kernel_map, kva, kva + PAGE_SIZE);
}
return rv;
}
static int
pwrite (struct proc *procp, unsigned int addr, unsigned int datum) {
int rv;
vm_map_t map, tmap;
vm_object_t object;
vm_offset_t kva = 0;
int page_offset; /* offset into page */
vm_offset_t pageno; /* page number */
vm_map_entry_t out_entry;
vm_prot_t out_prot;
boolean_t wired, single_use;
vm_offset_t off;
boolean_t fix_prot = 0;
/* Map page into kernel space */
1995-05-30 08:16:23 +00:00
map = &procp->p_vmspace->vm_map;
1995-05-30 08:16:23 +00:00
page_offset = addr - trunc_page(addr);
pageno = trunc_page(addr);
1995-05-30 08:16:23 +00:00
/*
* Check the permissions for the area we're interested in.
*/
if (vm_map_check_protection (map, pageno, pageno + PAGE_SIZE,
VM_PROT_WRITE) == FALSE) {
/*
* If the page was not writable, we make it so.
* XXX It is possible a page may *not* be read/executable,
* if a process changes that!
*/
fix_prot = 1;
/* The page isn't writable, so let's try making it so... */
if ((rv = vm_map_protect (map, pageno, pageno + PAGE_SIZE,
VM_PROT_ALL, 0)) != KERN_SUCCESS)
return EFAULT; /* I guess... */
}
/*
* Now we need to get the page. out_entry, out_prot, wired, and
* single_use aren't used. One would think the vm code would be
* a *bit* nicer... We use tmap because vm_map_lookup() can
* change the map argument.
*/
tmap = map;
rv = vm_map_lookup (&tmap, pageno, VM_PROT_WRITE, &out_entry,
&object, &off, &out_prot, &wired, &single_use);
if (rv != KERN_SUCCESS) {
return EINVAL;
}
/*
* Okay, we've got the page. Let's release tmap.
*/
vm_map_lookup_done (tmap, out_entry);
1995-05-30 08:16:23 +00:00
/*
* Fault the page in...
*/
vm_map_pageable(map, trunc_page(vtopte(pageno)),
trunc_page(vtopte(pageno)) + PAGE_SIZE, FALSE);
rv = vm_fault(map, pageno, VM_PROT_WRITE|VM_PROT_READ, FALSE);
vm_map_pageable(map, trunc_page(vtopte(pageno)),
trunc_page(vtopte(pageno)) + PAGE_SIZE, TRUE);
if (rv != KERN_SUCCESS)
return EFAULT;
/* Find space in kernel_map for the page we're interested in */
rv = vm_map_find (kernel_map, object, off, &kva, PAGE_SIZE, 1);
if (!rv) {
vm_object_reference (object);
rv = vm_map_pageable (kernel_map, kva, kva + PAGE_SIZE, 0);
if (!rv) {
bcopy (&datum, (caddr_t)kva + page_offset, sizeof datum);
}
vm_map_remove (kernel_map, kva, kva + PAGE_SIZE);
}
1995-05-30 08:16:23 +00:00
if (fix_prot)
vm_map_protect (map, pageno, pageno + PAGE_SIZE,
VM_PROT_READ|VM_PROT_EXECUTE, 0);
return rv;
}
1994-05-24 10:09:53 +00:00
/*
* Process debugging system call.
*/
struct ptrace_args {
int req;
pid_t pid;
caddr_t addr;
int data;
};
int
ptrace(curp, uap, retval)
struct proc *curp;
struct ptrace_args *uap;
int *retval;
1994-05-24 10:09:53 +00:00
{
struct proc *p;
int error = 0;
*retval = 0;
if (uap->req == PT_TRACE_ME) {
curp->p_flag |= P_TRACED;
return 0;
}
if ((p = pfind(uap->pid)) == NULL) {
return ESRCH;
}
1994-05-24 10:09:53 +00:00
#ifdef PT_ATTACH
if (uap->req != PT_ATTACH && (
(p->p_flag & P_TRACED) == 0 ||
(p->p_tptr && curp != p->p_tptr) ||
(!p->p_tptr && curp != p->p_pptr)))
return ESRCH;
#endif
#ifdef PT_ATTACH
if (uap->req != PT_ATTACH) {
#endif
if ((p->p_flag & P_TRACED) == 0)
return EPERM;
if (p->p_stat != SSTOP || (p->p_flag & P_WAITED) == 0)
return EBUSY;
#ifdef PT_ATTACH
}
#endif
1994-05-24 10:09:53 +00:00
/*
* XXX The PT_ATTACH code is completely broken. It will
* be obsoleted by a /proc filesystem, so is it worth it
* to fix it? (Answer, probably. So that'll be next,
* I guess.)
1994-05-24 10:09:53 +00:00
*/
switch (uap->req) {
#ifdef PT_ATTACH
case PT_ATTACH:
if (curp->p_ucred->cr_uid != 0 && (
curp->p_ucred->cr_uid != p->p_ucred->cr_uid ||
curp->p_ucred->cr_uid != p->p_cred->p_svuid))
return EACCES;
p->p_tptr = curp;
p->p_flag |= P_TRACED;
psignal(p, SIGSTOP);
return 0;
case PT_DETACH:
if ((unsigned)uap->data >= NSIG)
return EINVAL;
p->p_flag &= ~P_TRACED;
p->p_tptr = NULL;
psignal(p->p_pptr, SIGCHLD);
wakeup((caddr_t)p->p_pptr);
s = splhigh();
if (p->p_stat == SSTOP) {
p->p_xstat = uap->data;
setrunnable(p);
} else if (uap->data) {
psignal(p, uap->data);
}
splx(s);
return 0;
# ifdef PT_INHERIT
case PT_INHERIT:
if ((p->p_flag & P_TRACED) == 0)
return ESRCH;
return 0;
# endif /* PT_INHERIT */
#endif /* PT_ATTACH */
case PT_READ_I:
case PT_READ_D:
if ((error = pread (p, (unsigned int)uap->addr, retval)))
return error;
return 0;
case PT_WRITE_I:
case PT_WRITE_D:
if ((error = pwrite (p, (unsigned int)uap->addr,
(unsigned int)uap->data)))
return error;
return 0;
case PT_STEP:
if ((error = ptrace_single_step (p)))
return error;
/* fallthrough */
case PT_CONTINUE:
/*
* Continue at addr uap->addr with signal
* uap->data; if uap->addr is 1, then we just
* let the chips fall where they may.
*
* The only check I'll make right now is for
* uap->data to be larger than NSIG; if so, we return
* EINVAL.
*/
if (uap->data >= NSIG)
return EINVAL;
if (uap->addr != (caddr_t)1) {
fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
if ((error = ptrace_set_pc (p, (u_int)uap->addr)))
return error;
}
p->p_xstat = uap->data;
/* if (p->p_stat == SSTOP) */
setrunnable (p);
return 0;
case PT_READ_U:
if ((u_int)uap->addr > (UPAGES * NBPG - sizeof(int))) {
return EFAULT;
}
p->p_addr->u_kproc.kp_proc = *p;
fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
*retval = *(int*)((u_int)p->p_addr + (u_int)uap->addr);
return 0;
case PT_WRITE_U:
p->p_addr->u_kproc.kp_proc = *p;
fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
Fix security holes in sigreturn(), ptrace() and procfs. sigreturn() attempted to check for insecure and fatal eflags and segment selectors, but missed many cases and got the IOPL check back to front. The other syscalls didn't check at all. sys_process.c, machdep.c: Only allow PT_WRITE_U to write to the registers (ordinary and FP). psl.h, locore.s, machdep.c: Eliminate PSL_MBZ, PSL_MBO and PSL_USERCLR. We are not supposed to assume anything about the reserved bits. Use PSL_USERCHANGE and PSL_KERNEL instead. Rename PSL_USERSET to PSL_USER. exception.s: Define a private label for use by doreti when returning to user mode fails. machdep.c: In syscalls, allow changing only the eflags that can be changed on 486's in user mode (no longer attempt to allow benign IOPL changes; allow changing the nasty PSL_NT; don't allow changing the i586 bits). Don't attempt to check all the cases involving invalid selectors and %eip's. Just check for privilege violations and let the invalid things cause a trap. procfs_machdep.c: Call the ptrace register functions to do all the work for reading and writing ordinary registers and for single stepping. trap.c: Ignore traps caused by PSL_NT being set. Previously, users could cause a fatal trap in user mode by setting PSL_NT and executing an iret, and a fatal trap in kernel mode by setting PSL_NT and making a syscall. PSL_NT was cleared too late and not in enough modes to fix the problem. Make all traps in user mode (except T_NMI) nonfatal. Recover from traps caused by attempting to load invalid user registers in doreti by restarting the traps so that they appear to occur in user mode. --- Fix bogons that I noticed while fixing the above: psl.h: Fix some comments. Uniformize idempotency ifdef. exception.s, machdep.c: Remove rsvd[0-14]. rsvd0 hasn't been reserved since the 486 came out. Replace rsvd0 by `align'. rsvd[0-11] used wrong (magic non-unique) trap numbers. Replace rsvd[1-14] by rsvd. locore.s: Enable alignment check flag on 486's and 586's. machdep.c: Use a better type for kstack[]. Use TFREGP() to find the registers. Reformat ptrace functions from SEF to something closer to KNF. procfs_machdep.c: The wrong pointer to the registers got fixed as a side effect. Implement reading and writing of FP registers. /proc/*/*regs now work (only) for processes that are in memory. Clean up comments. trap.c, trap.h: Remove unused trap types.
1995-01-14 13:20:26 +00:00
return ptrace_write_u(p, (vm_offset_t)uap->addr, uap->data);
case PT_KILL:
p->p_xstat = SIGKILL;
setrunnable(p);
return 0;
#ifdef PT_GETREGS
case PT_GETREGS:
/*
* copyout the registers into addr. There's no
* size constraint!!! *GRRR*
*/
return ptrace_getregs(p, uap->addr);
case PT_SETREGS:
/*
* copyin the registers from addr. Again, no
* size constraint!!! *GRRRR*
*/
return ptrace_setregs (p, uap->addr);
#endif /* PT_GETREGS */
default:
break;
}
return 0;
1994-05-24 10:09:53 +00:00
}
int
trace_req(p)
struct proc *p;
1994-05-24 10:09:53 +00:00
{
return 1;
1994-05-24 10:09:53 +00:00
}