leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity
3b2ce0b178
linux/arch/ia64/kernel/ptrace.c
Petr Tesarik 3b2ce0b178 [IA64] Synchronize kernel RSE to user-space and back 
This is base kernel patch for ptrace RSE bug. It's basically a backport
from the utrace RSE patch I sent out several weeks ago. please review.

when a thread is stopped (ptraced), debugger might change thread's user
stack (change memory directly), and we must avoid the RSE stored in
kernel to override user stack (user space's RSE is newer than kernel's
in the case). To workaround the issue, we copy kernel RSE to user RSE
before the task is stopped, so user RSE has updated data.  we then copy
user RSE to kernel after the task is resummed from traced stop and
kernel will use the newer RSE to return to user.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
CC: Roland McGrath <roland@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-02-08 12:01:18 -08:00

1757 lines
46 KiB
C
Raw Blame History

/*
* Kernel support for the ptrace() and syscall tracing interfaces.
*
* Copyright (C) 1999-2005 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* Derived from the x86 and Alpha versions.
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/smp_lock.h>
#include <linux/user.h>
#include <linux/security.h>
#include <linux/audit.h>
#include <linux/signal.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/ptrace_offsets.h>
#include <asm/rse.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/unwind.h>
#ifdef CONFIG_PERFMON
#include <asm/perfmon.h>
#endif
#include "entry.h"
/*
* Bits in the PSR that we allow ptrace() to change:
* be, up, ac, mfl, mfh (the user mask; five bits total)
* db (debug breakpoint fault; one bit)
* id (instruction debug fault disable; one bit)
* dd (data debug fault disable; one bit)
* ri (restart instruction; two bits)
* is (instruction set; one bit)
*/
#define IPSR_MASK (IA64_PSR_UM | IA64_PSR_DB | IA64_PSR_IS \
| IA64_PSR_ID | IA64_PSR_DD | IA64_PSR_RI)
#define MASK(nbits) ((1UL << (nbits)) - 1) /* mask with NBITS bits set */
#define PFM_MASK MASK(38)
#define PTRACE_DEBUG 0
#if PTRACE_DEBUG
# define dprintk(format...) printk(format)
# define inline
#else
# define dprintk(format...)
#endif
/* Return TRUE if PT was created due to kernel-entry via a system-call. */
static inline int
in_syscall (struct pt_regs *pt)
{
return (long) pt->cr_ifs >= 0;
}
/*
* Collect the NaT bits for r1-r31 from scratch_unat and return a NaT
* bitset where bit i is set iff the NaT bit of register i is set.
*/
unsigned long
ia64_get_scratch_nat_bits (struct pt_regs *pt, unsigned long scratch_unat)
{
# define GET_BITS(first, last, unat) \
({ \
unsigned long bit = ia64_unat_pos(&pt->r##first); \
unsigned long nbits = (last - first + 1); \
unsigned long mask = MASK(nbits) << first; \
unsigned long dist; \
if (bit < first) \
dist = 64 + bit - first; \
else \
dist = bit - first; \
ia64_rotr(unat, dist) & mask; \
})
unsigned long val;
/*
* Registers that are stored consecutively in struct pt_regs
* can be handled in parallel. If the register order in
* struct_pt_regs changes, this code MUST be updated.
*/
val = GET_BITS( 1, 1, scratch_unat);
val |= GET_BITS( 2, 3, scratch_unat);
val |= GET_BITS(12, 13, scratch_unat);
val |= GET_BITS(14, 14, scratch_unat);
val |= GET_BITS(15, 15, scratch_unat);
val |= GET_BITS( 8, 11, scratch_unat);
val |= GET_BITS(16, 31, scratch_unat);
return val;
# undef GET_BITS
}
/*
* Set the NaT bits for the scratch registers according to NAT and
* return the resulting unat (assuming the scratch registers are
* stored in PT).
*/
unsigned long
ia64_put_scratch_nat_bits (struct pt_regs *pt, unsigned long nat)
{
# define PUT_BITS(first, last, nat) \
({ \
unsigned long bit = ia64_unat_pos(&pt->r##first); \
unsigned long nbits = (last - first + 1); \
unsigned long mask = MASK(nbits) << first; \
long dist; \
if (bit < first) \
dist = 64 + bit - first; \
else \
dist = bit - first; \
ia64_rotl(nat & mask, dist); \
})
unsigned long scratch_unat;
/*
* Registers that are stored consecutively in struct pt_regs
* can be handled in parallel. If the register order in
* struct_pt_regs changes, this code MUST be updated.
*/
scratch_unat = PUT_BITS( 1, 1, nat);
scratch_unat |= PUT_BITS( 2, 3, nat);
scratch_unat |= PUT_BITS(12, 13, nat);
scratch_unat |= PUT_BITS(14, 14, nat);
scratch_unat |= PUT_BITS(15, 15, nat);
scratch_unat |= PUT_BITS( 8, 11, nat);
scratch_unat |= PUT_BITS(16, 31, nat);
return scratch_unat;
# undef PUT_BITS
}
#define IA64_MLX_TEMPLATE 0x2
#define IA64_MOVL_OPCODE 6
void
ia64_increment_ip (struct pt_regs *regs)
{
unsigned long w0, ri = ia64_psr(regs)->ri + 1;
if (ri > 2) {
ri = 0;
regs->cr_iip += 16;
} else if (ri == 2) {
get_user(w0, (char __user *) regs->cr_iip + 0);
if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) {
/*
* rfi'ing to slot 2 of an MLX bundle causes
* an illegal operation fault. We don't want
* that to happen...
*/
ri = 0;
regs->cr_iip += 16;
}
}
ia64_psr(regs)->ri = ri;
}
void
ia64_decrement_ip (struct pt_regs *regs)
{
unsigned long w0, ri = ia64_psr(regs)->ri - 1;
if (ia64_psr(regs)->ri == 0) {
regs->cr_iip -= 16;
ri = 2;
get_user(w0, (char __user *) regs->cr_iip + 0);
if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) {
/*
* rfi'ing to slot 2 of an MLX bundle causes
* an illegal operation fault. We don't want
* that to happen...
*/
ri = 1;
}
}
ia64_psr(regs)->ri = ri;
}
/*
* This routine is used to read an rnat bits that are stored on the
* kernel backing store. Since, in general, the alignment of the user
* and kernel are different, this is not completely trivial. In
* essence, we need to construct the user RNAT based on up to two
* kernel RNAT values and/or the RNAT value saved in the child's
* pt_regs.
*
* user rbs
*
* +--------+ <-- lowest address
* | slot62 |
* +--------+
* | rnat | 0x....1f8
* +--------+
* | slot00 | \
* +--------+ |
* | slot01 | > child_regs->ar_rnat
* +--------+ |
* | slot02 | / kernel rbs
* +--------+ +--------+
* <- child_regs->ar_bspstore | slot61 | <-- krbs
* +- - - - + +--------+
* | slot62 |
* +- - - - + +--------+
* | rnat |
* +- - - - + +--------+
* vrnat | slot00 |
* +- - - - + +--------+
* = =
* +--------+
* | slot00 | \
* +--------+ |
* | slot01 | > child_stack->ar_rnat
* +--------+ |
* | slot02 | /
* +--------+
* <--- child_stack->ar_bspstore
*
* The way to think of this code is as follows: bit 0 in the user rnat
* corresponds to some bit N (0 <= N <= 62) in one of the kernel rnat
* value. The kernel rnat value holding this bit is stored in
* variable rnat0. rnat1 is loaded with the kernel rnat value that
* form the upper bits of the user rnat value.
*
* Boundary cases:
*
* o when reading the rnat "below" the first rnat slot on the kernel
* backing store, rnat0/rnat1 are set to 0 and the low order bits are
* merged in from pt->ar_rnat.
*
* o when reading the rnat "above" the last rnat slot on the kernel
* backing store, rnat0/rnat1 gets its value from sw->ar_rnat.
*/
static unsigned long
get_rnat (struct task_struct *task, struct switch_stack *sw,
unsigned long *krbs, unsigned long *urnat_addr,
unsigned long *urbs_end)
{
unsigned long rnat0 = 0, rnat1 = 0, urnat = 0, *slot0_kaddr;
unsigned long umask = 0, mask, m;
unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift;
long num_regs, nbits;
struct pt_regs *pt;
pt = task_pt_regs(task);
kbsp = (unsigned long *) sw->ar_bspstore;
ubspstore = (unsigned long *) pt->ar_bspstore;
if (urbs_end < urnat_addr)
nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_end);
else
nbits = 63;
mask = MASK(nbits);
/*
* First, figure out which bit number slot 0 in user-land maps
* to in the kernel rnat. Do this by figuring out how many
* register slots we're beyond the user's backingstore and
* then computing the equivalent address in kernel space.
*/
num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1);
slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs);
shift = ia64_rse_slot_num(slot0_kaddr);
rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr);
rnat0_kaddr = rnat1_kaddr - 64;
if (ubspstore + 63 > urnat_addr) {
/* some bits need to be merged in from pt->ar_rnat */
umask = MASK(ia64_rse_slot_num(ubspstore)) & mask;
urnat = (pt->ar_rnat & umask);
mask &= ~umask;
if (!mask)
return urnat;
}
m = mask << shift;
if (rnat0_kaddr >= kbsp)
rnat0 = sw->ar_rnat;
else if (rnat0_kaddr > krbs)
rnat0 = *rnat0_kaddr;
urnat |= (rnat0 & m) >> shift;
m = mask >> (63 - shift);
if (rnat1_kaddr >= kbsp)
rnat1 = sw->ar_rnat;
else if (rnat1_kaddr > krbs)
rnat1 = *rnat1_kaddr;
urnat |= (rnat1 & m) << (63 - shift);
return urnat;
}
/*
* The reverse of get_rnat.
*/
static void
put_rnat (struct task_struct *task, struct switch_stack *sw,
unsigned long *krbs, unsigned long *urnat_addr, unsigned long urnat,
unsigned long *urbs_end)
{
unsigned long rnat0 = 0, rnat1 = 0, *slot0_kaddr, umask = 0, mask, m;
unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift;
long num_regs, nbits;
struct pt_regs *pt;
unsigned long cfm, *urbs_kargs;
pt = task_pt_regs(task);
kbsp = (unsigned long *) sw->ar_bspstore;
ubspstore = (unsigned long *) pt->ar_bspstore;
urbs_kargs = urbs_end;
if (in_syscall(pt)) {
/*
* If entered via syscall, don't allow user to set rnat bits
* for syscall args.
*/
cfm = pt->cr_ifs;
urbs_kargs = ia64_rse_skip_regs(urbs_end, -(cfm & 0x7f));
}
if (urbs_kargs >= urnat_addr)
nbits = 63;
else {
if ((urnat_addr - 63) >= urbs_kargs)
return;
nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_kargs);
}
mask = MASK(nbits);
/*
* First, figure out which bit number slot 0 in user-land maps
* to in the kernel rnat. Do this by figuring out how many
* register slots we're beyond the user's backingstore and
* then computing the equivalent address in kernel space.
*/
num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1);
slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs);
shift = ia64_rse_slot_num(slot0_kaddr);
rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr);
rnat0_kaddr = rnat1_kaddr - 64;
if (ubspstore + 63 > urnat_addr) {
/* some bits need to be place in pt->ar_rnat: */
umask = MASK(ia64_rse_slot_num(ubspstore)) & mask;
pt->ar_rnat = (pt->ar_rnat & ~umask) | (urnat & umask);
mask &= ~umask;
if (!mask)
return;
}
/*
* Note: Section 11.1 of the EAS guarantees that bit 63 of an
* rnat slot is ignored. so we don't have to clear it here.
*/
rnat0 = (urnat << shift);
m = mask << shift;
if (rnat0_kaddr >= kbsp)
sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat0 & m);
else if (rnat0_kaddr > krbs)
*rnat0_kaddr = ((*rnat0_kaddr & ~m) | (rnat0 & m));
rnat1 = (urnat >> (63 - shift));
m = mask >> (63 - shift);
if (rnat1_kaddr >= kbsp)
sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat1 & m);
else if (rnat1_kaddr > krbs)
*rnat1_kaddr = ((*rnat1_kaddr & ~m) | (rnat1 & m));
}
static inline int
on_kernel_rbs (unsigned long addr, unsigned long bspstore,
unsigned long urbs_end)
{
unsigned long *rnat_addr = ia64_rse_rnat_addr((unsigned long *)
urbs_end);
return (addr >= bspstore && addr <= (unsigned long) rnat_addr);
}
/*
* Read a word from the user-level backing store of task CHILD. ADDR
* is the user-level address to read the word from, VAL a pointer to
* the return value, and USER_BSP gives the end of the user-level
* backing store (i.e., it's the address that would be in ar.bsp after
* the user executed a "cover" instruction).
*
* This routine takes care of accessing the kernel register backing
* store for those registers that got spilled there. It also takes
* care of calculating the appropriate RNaT collection words.
*/
long
ia64_peek (struct task_struct *child, struct switch_stack *child_stack,
unsigned long user_rbs_end, unsigned long addr, long *val)
{
unsigned long *bspstore, *krbs, regnum, *laddr, *urbs_end, *rnat_addr;
struct pt_regs *child_regs;
size_t copied;
long ret;
urbs_end = (long *) user_rbs_end;
laddr = (unsigned long *) addr;
child_regs = task_pt_regs(child);
bspstore = (unsigned long *) child_regs->ar_bspstore;
krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
if (on_kernel_rbs(addr, (unsigned long) bspstore,
(unsigned long) urbs_end))
{
/*
* Attempt to read the RBS in an area that's actually
* on the kernel RBS => read the corresponding bits in
* the kernel RBS.
*/
rnat_addr = ia64_rse_rnat_addr(laddr);
ret = get_rnat(child, child_stack, krbs, rnat_addr, urbs_end);
if (laddr == rnat_addr) {
/* return NaT collection word itself */
*val = ret;
return 0;
}
if (((1UL << ia64_rse_slot_num(laddr)) & ret) != 0) {
/*
* It is implementation dependent whether the
* data portion of a NaT value gets saved on a
* st8.spill or RSE spill (e.g., see EAS 2.6,
* 4.4.4.6 Register Spill and Fill). To get
* consistent behavior across all possible
* IA-64 implementations, we return zero in
* this case.
*/
*val = 0;
return 0;
}
if (laddr < urbs_end) {
/*
* The desired word is on the kernel RBS and
* is not a NaT.
*/
regnum = ia64_rse_num_regs(bspstore, laddr);
*val = *ia64_rse_skip_regs(krbs, regnum);
return 0;
}
}
copied = access_process_vm(child, addr, &ret, sizeof(ret), 0);
if (copied != sizeof(ret))
return -EIO;
*val = ret;
return 0;
}
long
ia64_poke (struct task_struct *child, struct switch_stack *child_stack,
unsigned long user_rbs_end, unsigned long addr, long val)
{
unsigned long *bspstore, *krbs, regnum, *laddr;
unsigned long *urbs_end = (long *) user_rbs_end;
struct pt_regs *child_regs;
laddr = (unsigned long *) addr;
child_regs = task_pt_regs(child);
bspstore = (unsigned long *) child_regs->ar_bspstore;
krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
if (on_kernel_rbs(addr, (unsigned long) bspstore,
(unsigned long) urbs_end))
{
/*
* Attempt to write the RBS in an area that's actually
* on the kernel RBS => write the corresponding bits
* in the kernel RBS.
*/
if (ia64_rse_is_rnat_slot(laddr))
put_rnat(child, child_stack, krbs, laddr, val,
urbs_end);
else {
if (laddr < urbs_end) {
regnum = ia64_rse_num_regs(bspstore, laddr);
*ia64_rse_skip_regs(krbs, regnum) = val;
}
}
} else if (access_process_vm(child, addr, &val, sizeof(val), 1)
!= sizeof(val))
return -EIO;
return 0;
}
/*
* Calculate the address of the end of the user-level register backing
* store. This is the address that would have been stored in ar.bsp
* if the user had executed a "cover" instruction right before
* entering the kernel. If CFMP is not NULL, it is used to return the
* "current frame mask" that was active at the time the kernel was
* entered.
*/
unsigned long
ia64_get_user_rbs_end (struct task_struct *child, struct pt_regs *pt,
unsigned long *cfmp)
{
unsigned long *krbs, *bspstore, cfm = pt->cr_ifs;
long ndirty;
krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
bspstore = (unsigned long *) pt->ar_bspstore;
ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));
if (in_syscall(pt))
ndirty += (cfm & 0x7f);
else
cfm &= ~(1UL << 63); /* clear valid bit */
if (cfmp)
*cfmp = cfm;
return (unsigned long) ia64_rse_skip_regs(bspstore, ndirty);
}
/*
* Synchronize (i.e, write) the RSE backing store living in kernel
* space to the VM of the CHILD task. SW and PT are the pointers to
* the switch_stack and pt_regs structures, respectively.
* USER_RBS_END is the user-level address at which the backing store
* ends.
*/
long
ia64_sync_user_rbs (struct task_struct *child, struct switch_stack *sw,
unsigned long user_rbs_start, unsigned long user_rbs_end)
{
unsigned long addr, val;
long ret;
/* now copy word for word from kernel rbs to user rbs: */
for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
ret = ia64_peek(child, sw, user_rbs_end, addr, &val);
if (ret < 0)
return ret;
if (access_process_vm(child, addr, &val, sizeof(val), 1)
!= sizeof(val))
return -EIO;
}
return 0;
}
static long
ia64_sync_kernel_rbs (struct task_struct *child, struct switch_stack *sw,
unsigned long user_rbs_start, unsigned long user_rbs_end)
{
unsigned long addr, val;
long ret;
/* now copy word for word from user rbs to kernel rbs: */
for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
if (access_process_vm(child, addr, &val, sizeof(val), 0)
!= sizeof(val))
return -EIO;
ret = ia64_poke(child, sw, user_rbs_end, addr, val);
if (ret < 0)
return ret;
}
return 0;
}
typedef long (*syncfunc_t)(struct task_struct *, struct switch_stack *,
unsigned long, unsigned long);
static void do_sync_rbs(struct unw_frame_info *info, void *arg)
{
struct pt_regs *pt;
unsigned long urbs_end;
syncfunc_t fn = arg;
if (unw_unwind_to_user(info) < 0)
return;
pt = task_pt_regs(info->task);
urbs_end = ia64_get_user_rbs_end(info->task, pt, NULL);
fn(info->task, info->sw, pt->ar_bspstore, urbs_end);
}
/*
* when a thread is stopped (ptraced), debugger might change thread's user
* stack (change memory directly), and we must avoid the RSE stored in kernel
* to override user stack (user space's RSE is newer than kernel's in the
* case). To workaround the issue, we copy kernel RSE to user RSE before the
* task is stopped, so user RSE has updated data. we then copy user RSE to
* kernel after the task is resummed from traced stop and kernel will use the
* newer RSE to return to user. TIF_RESTORE_RSE is the flag to indicate we need
* synchronize user RSE to kernel.
*/
void ia64_ptrace_stop(void)
{
if (test_and_set_tsk_thread_flag(current, TIF_RESTORE_RSE))
return;
tsk_set_notify_resume(current);
unw_init_running(do_sync_rbs, ia64_sync_user_rbs);
}
/*
* This is called to read back the register backing store.
*/
void ia64_sync_krbs(void)
{
clear_tsk_thread_flag(current, TIF_RESTORE_RSE);
tsk_clear_notify_resume(current);
unw_init_running(do_sync_rbs, ia64_sync_kernel_rbs);
}
static inline int
thread_matches (struct task_struct *thread, unsigned long addr)
{
unsigned long thread_rbs_end;
struct pt_regs *thread_regs;
if (ptrace_check_attach(thread, 0) < 0)
/*
* If the thread is not in an attachable state, we'll
* ignore it. The net effect is that if ADDR happens
* to overlap with the portion of the thread's
* register backing store that is currently residing
* on the thread's kernel stack, then ptrace() may end
* up accessing a stale value. But if the thread
* isn't stopped, that's a problem anyhow, so we're
* doing as well as we can...
*/
return 0;
thread_regs = task_pt_regs(thread);
thread_rbs_end = ia64_get_user_rbs_end(thread, thread_regs, NULL);
if (!on_kernel_rbs(addr, thread_regs->ar_bspstore, thread_rbs_end))
return 0;
return 1; /* looks like we've got a winner */
}
/*
* GDB apparently wants to be able to read the register-backing store
* of any thread when attached to a given process. If we are peeking
* or poking an address that happens to reside in the kernel-backing
* store of another thread, we need to attach to that thread, because
* otherwise we end up accessing stale data.
*
* task_list_lock must be read-locked before calling this routine!
*/
static struct task_struct *
find_thread_for_addr (struct task_struct *child, unsigned long addr)
{
struct task_struct *p;
struct mm_struct *mm;
struct list_head *this, *next;
int mm_users;
if (!(mm = get_task_mm(child)))
return child;
/* -1 because of our get_task_mm(): */
mm_users = atomic_read(&mm->mm_users) - 1;
if (mm_users <= 1)
goto out; /* not multi-threaded */
/*
* Traverse the current process' children list. Every task that
* one attaches to becomes a child. And it is only attached children
* of the debugger that are of interest (ptrace_check_attach checks
* for this).
*/
list_for_each_safe(this, next, &current->children) {
p = list_entry(this, struct task_struct, sibling);
if (p->tgid != child->tgid)
continue;
if (thread_matches(p, addr)) {
child = p;
goto out;
}
}
out:
mmput(mm);
return child;
}
/*
* Write f32-f127 back to task->thread.fph if it has been modified.
*/
inline void
ia64_flush_fph (struct task_struct *task)
{
struct ia64_psr *psr = ia64_psr(task_pt_regs(task));
/*
* Prevent migrating this task while
* we're fiddling with the FPU state
*/
preempt_disable();
if (ia64_is_local_fpu_owner(task) && psr->mfh) {
psr->mfh = 0;
task->thread.flags |= IA64_THREAD_FPH_VALID;
ia64_save_fpu(&task->thread.fph[0]);
}
preempt_enable();
}
/*
* Sync the fph state of the task so that it can be manipulated
* through thread.fph. If necessary, f32-f127 are written back to
* thread.fph or, if the fph state hasn't been used before, thread.fph
* is cleared to zeroes. Also, access to f32-f127 is disabled to
* ensure that the task picks up the state from thread.fph when it
* executes again.
*/
void
ia64_sync_fph (struct task_struct *task)
{
struct ia64_psr *psr = ia64_psr(task_pt_regs(task));
ia64_flush_fph(task);
if (!(task->thread.flags & IA64_THREAD_FPH_VALID)) {
task->thread.flags |= IA64_THREAD_FPH_VALID;
memset(&task->thread.fph, 0, sizeof(task->thread.fph));
}
ia64_drop_fpu(task);
psr->dfh = 1;
}
static int
access_fr (struct unw_frame_info *info, int regnum, int hi,
unsigned long *data, int write_access)
{
struct ia64_fpreg fpval;
int ret;
ret = unw_get_fr(info, regnum, &fpval);
if (ret < 0)
return ret;
if (write_access) {
fpval.u.bits[hi] = *data;
ret = unw_set_fr(info, regnum, fpval);
} else
*data = fpval.u.bits[hi];
return ret;
}
/*
* Change the machine-state of CHILD such that it will return via the normal
* kernel exit-path, rather than the syscall-exit path.
*/
static void
convert_to_non_syscall (struct task_struct *child, struct pt_regs *pt,
unsigned long cfm)
{
struct unw_frame_info info, prev_info;
unsigned long ip, sp, pr;
unw_init_from_blocked_task(&info, child);
while (1) {
prev_info = info;
if (unw_unwind(&info) < 0)
return;
unw_get_sp(&info, &sp);
if ((long)((unsigned long)child + IA64_STK_OFFSET - sp)
< IA64_PT_REGS_SIZE) {
dprintk("ptrace.%s: ran off the top of the kernel "
"stack\n", __FUNCTION__);
return;
}
if (unw_get_pr (&prev_info, &pr) < 0) {
unw_get_rp(&prev_info, &ip);
dprintk("ptrace.%s: failed to read "
"predicate register (ip=0x%lx)\n",
__FUNCTION__, ip);
return;
}
if (unw_is_intr_frame(&info)
&& (pr & (1UL << PRED_USER_STACK)))
break;
}
/*
* Note: at the time of this call, the target task is blocked
* in notify_resume_user() and by clearling PRED_LEAVE_SYSCALL
* (aka, "pLvSys") we redirect execution from
* .work_pending_syscall_end to .work_processed_kernel.
*/
unw_get_pr(&prev_info, &pr);
pr &= ~((1UL << PRED_SYSCALL) | (1UL << PRED_LEAVE_SYSCALL));
pr |= (1UL << PRED_NON_SYSCALL);
unw_set_pr(&prev_info, pr);
pt->cr_ifs = (1UL << 63) | cfm;
/*
* Clear the memory that is NOT written on syscall-entry to
* ensure we do not leak kernel-state to user when execution
* resumes.
*/
pt->r2 = 0;
pt->r3 = 0;
pt->r14 = 0;
memset(&pt->r16, 0, 16*8); /* clear r16-r31 */
memset(&pt->f6, 0, 6*16); /* clear f6-f11 */
pt->b7 = 0;
pt->ar_ccv = 0;
pt->ar_csd = 0;
pt->ar_ssd = 0;
}
static int
access_nat_bits (struct task_struct *child, struct pt_regs *pt,
struct unw_frame_info *info,
unsigned long *data, int write_access)
{
unsigned long regnum, nat_bits, scratch_unat, dummy = 0;
char nat = 0;
if (write_access) {
nat_bits = *data;
scratch_unat = ia64_put_scratch_nat_bits(pt, nat_bits);
if (unw_set_ar(info, UNW_AR_UNAT, scratch_unat) < 0) {
dprintk("ptrace: failed to set ar.unat\n");
return -1;
}
for (regnum = 4; regnum <= 7; ++regnum) {
unw_get_gr(info, regnum, &dummy, &nat);
unw_set_gr(info, regnum, dummy,
(nat_bits >> regnum) & 1);
}
} else {
if (unw_get_ar(info, UNW_AR_UNAT, &scratch_unat) < 0) {
dprintk("ptrace: failed to read ar.unat\n");
return -1;
}
nat_bits = ia64_get_scratch_nat_bits(pt, scratch_unat);
for (regnum = 4; regnum <= 7; ++regnum) {
unw_get_gr(info, regnum, &dummy, &nat);
nat_bits |= (nat != 0) << regnum;
}
*data = nat_bits;
}
return 0;
}
static int
access_uarea (struct task_struct *child, unsigned long addr,
unsigned long *data, int write_access)
{
unsigned long *ptr, regnum, urbs_end, rnat_addr, cfm;
struct switch_stack *sw;
struct pt_regs *pt;
# define pt_reg_addr(pt, reg) ((void *) \
((unsigned long) (pt) \
+ offsetof(struct pt_regs, reg)))
pt = task_pt_regs(child);
sw = (struct switch_stack *) (child->thread.ksp + 16);
if ((addr & 0x7) != 0) {
dprintk("ptrace: unaligned register address 0x%lx\n", addr);
return -1;
}
if (addr < PT_F127 + 16) {
/* accessing fph */
if (write_access)
ia64_sync_fph(child);
else
ia64_flush_fph(child);
ptr = (unsigned long *)
((unsigned long) &child->thread.fph + addr);
} else if ((addr >= PT_F10) && (addr < PT_F11 + 16)) {
/* scratch registers untouched by kernel (saved in pt_regs) */
ptr = pt_reg_addr(pt, f10) + (addr - PT_F10);
} else if (addr >= PT_F12 && addr < PT_F15 + 16) {
/*
* Scratch registers untouched by kernel (saved in
* switch_stack).
*/
ptr = (unsigned long *) ((long) sw
+ (addr - PT_NAT_BITS - 32));
} else if (addr < PT_AR_LC + 8) {
/* preserved state: */
struct unw_frame_info info;
char nat = 0;
int ret;
unw_init_from_blocked_task(&info, child);
if (unw_unwind_to_user(&info) < 0)
return -1;
switch (addr) {
case PT_NAT_BITS:
return access_nat_bits(child, pt, &info,
data, write_access);
case PT_R4: case PT_R5: case PT_R6: case PT_R7:
if (write_access) {
/* read NaT bit first: */
unsigned long dummy;
ret = unw_get_gr(&info, (addr - PT_R4)/8 + 4,
&dummy, &nat);
if (ret < 0)
return ret;
}
return unw_access_gr(&info, (addr - PT_R4)/8 + 4, data,
&nat, write_access);
case PT_B1: case PT_B2: case PT_B3:
case PT_B4: case PT_B5:
return unw_access_br(&info, (addr - PT_B1)/8 + 1, data,
write_access);
case PT_AR_EC:
return unw_access_ar(&info, UNW_AR_EC, data,
write_access);
case PT_AR_LC:
return unw_access_ar(&info, UNW_AR_LC, data,
write_access);
default:
if (addr >= PT_F2 && addr < PT_F5 + 16)
return access_fr(&info, (addr - PT_F2)/16 + 2,
(addr & 8) != 0, data,
write_access);
else if (addr >= PT_F16 && addr < PT_F31 + 16)
return access_fr(&info,
(addr - PT_F16)/16 + 16,
(addr & 8) != 0,
data, write_access);
else {
dprintk("ptrace: rejecting access to register "
"address 0x%lx\n", addr);
return -1;
}
}
} else if (addr < PT_F9+16) {
/* scratch state */
switch (addr) {
case PT_AR_BSP:
/*
* By convention, we use PT_AR_BSP to refer to
* the end of the user-level backing store.
* Use ia64_rse_skip_regs(PT_AR_BSP, -CFM.sof)
* to get the real value of ar.bsp at the time
* the kernel was entered.
*
* Furthermore, when changing the contents of
* PT_AR_BSP (or PT_CFM) we MUST copy any
* users-level stacked registers that are
* stored on the kernel stack back to
* user-space because otherwise, we might end
* up clobbering kernel stacked registers.
* Also, if this happens while the task is
* blocked in a system call, which convert the
* state such that the non-system-call exit
* path is used. This ensures that the proper
* state will be picked up when resuming
* execution. However, it *also* means that
* once we write PT_AR_BSP/PT_CFM, it won't be
* possible to modify the syscall arguments of
* the pending system call any longer. This
* shouldn't be an issue because modifying
* PT_AR_BSP/PT_CFM generally implies that
* we're either abandoning the pending system
* call or that we defer it's re-execution
* (e.g., due to GDB doing an inferior
* function call).
*/
urbs_end = ia64_get_user_rbs_end(child, pt, &cfm);
if (write_access) {
if (*data != urbs_end) {
if (ia64_sync_user_rbs(child, sw,
pt->ar_bspstore,
urbs_end) < 0)
return -1;
if (in_syscall(pt))
convert_to_non_syscall(child,
pt,
cfm);
/*
* Simulate user-level write
* of ar.bsp:
*/
pt->loadrs = 0;
pt->ar_bspstore = *data;
}
} else
*data = urbs_end;
return 0;
case PT_CFM:
urbs_end = ia64_get_user_rbs_end(child, pt, &cfm);
if (write_access) {
if (((cfm ^ *data) & PFM_MASK) != 0) {
if (ia64_sync_user_rbs(child, sw,
pt->ar_bspstore,
urbs_end) < 0)
return -1;
if (in_syscall(pt))
convert_to_non_syscall(child,
pt,
cfm);
pt->cr_ifs = ((pt->cr_ifs & ~PFM_MASK)
| (*data & PFM_MASK));
}
} else
*data = cfm;
return 0;
case PT_CR_IPSR:
if (write_access) {
unsigned long tmp = *data;
/* psr.ri==3 is a reserved value: SDM 2:25 */
if ((tmp & IA64_PSR_RI) == IA64_PSR_RI)
tmp &= ~IA64_PSR_RI;
pt->cr_ipsr = ((tmp & IPSR_MASK)
| (pt->cr_ipsr & ~IPSR_MASK));
} else
*data = (pt->cr_ipsr & IPSR_MASK);
return 0;
case PT_AR_RSC:
if (write_access)
pt->ar_rsc = *data | (3 << 2); /* force PL3 */
else
*data = pt->ar_rsc;
return 0;
case PT_AR_RNAT:
urbs_end = ia64_get_user_rbs_end(child, pt, NULL);
rnat_addr = (long) ia64_rse_rnat_addr((long *)
urbs_end);
if (write_access)
return ia64_poke(child, sw, urbs_end,
rnat_addr, *data);
else
return ia64_peek(child, sw, urbs_end,
rnat_addr, data);
case PT_R1:
ptr = pt_reg_addr(pt, r1);
break;
case PT_R2: case PT_R3:
ptr = pt_reg_addr(pt, r2) + (addr - PT_R2);
break;
case PT_R8: case PT_R9: case PT_R10: case PT_R11:
ptr = pt_reg_addr(pt, r8) + (addr - PT_R8);
break;
case PT_R12: case PT_R13:
ptr = pt_reg_addr(pt, r12) + (addr - PT_R12);
break;
case PT_R14:
ptr = pt_reg_addr(pt, r14);
break;
case PT_R15:
ptr = pt_reg_addr(pt, r15);
break;
case PT_R16: case PT_R17: case PT_R18: case PT_R19:
case PT_R20: case PT_R21: case PT_R22: case PT_R23:
case PT_R24: case PT_R25: case PT_R26: case PT_R27:
case PT_R28: case PT_R29: case PT_R30: case PT_R31:
ptr = pt_reg_addr(pt, r16) + (addr - PT_R16);
break;
case PT_B0:
ptr = pt_reg_addr(pt, b0);
break;
case PT_B6:
ptr = pt_reg_addr(pt, b6);
break;
case PT_B7:
ptr = pt_reg_addr(pt, b7);
break;
case PT_F6: case PT_F6+8: case PT_F7: case PT_F7+8:
case PT_F8: case PT_F8+8: case PT_F9: case PT_F9+8:
ptr = pt_reg_addr(pt, f6) + (addr - PT_F6);
break;
case PT_AR_BSPSTORE:
ptr = pt_reg_addr(pt, ar_bspstore);
break;
case PT_AR_UNAT:
ptr = pt_reg_addr(pt, ar_unat);
break;
case PT_AR_PFS:
ptr = pt_reg_addr(pt, ar_pfs);
break;
case PT_AR_CCV:
ptr = pt_reg_addr(pt, ar_ccv);
break;
case PT_AR_FPSR:
ptr = pt_reg_addr(pt, ar_fpsr);
break;
case PT_CR_IIP:
ptr = pt_reg_addr(pt, cr_iip);
break;
case PT_PR:
ptr = pt_reg_addr(pt, pr);
break;
/* scratch register */
default:
/* disallow accessing anything else... */
dprintk("ptrace: rejecting access to register "
"address 0x%lx\n", addr);
return -1;
}
} else if (addr <= PT_AR_SSD) {
ptr = pt_reg_addr(pt, ar_csd) + (addr - PT_AR_CSD);
} else {
/* access debug registers */
if (addr >= PT_IBR) {
regnum = (addr - PT_IBR) >> 3;
ptr = &child->thread.ibr[0];
} else {
regnum = (addr - PT_DBR) >> 3;
ptr = &child->thread.dbr[0];
}
if (regnum >= 8) {
dprintk("ptrace: rejecting access to register "
"address 0x%lx\n", addr);
return -1;
}
#ifdef CONFIG_PERFMON
/*
* Check if debug registers are used by perfmon. This
* test must be done once we know that we can do the
* operation, i.e. the arguments are all valid, but
* before we start modifying the state.
*
* Perfmon needs to keep a count of how many processes
* are trying to modify the debug registers for system
* wide monitoring sessions.
*
* We also include read access here, because they may
* cause the PMU-installed debug register state
* (dbr[], ibr[]) to be reset. The two arrays are also
* used by perfmon, but we do not use
* IA64_THREAD_DBG_VALID. The registers are restored
* by the PMU context switch code.
*/
if (pfm_use_debug_registers(child)) return -1;
#endif
if (!(child->thread.flags & IA64_THREAD_DBG_VALID)) {
child->thread.flags |= IA64_THREAD_DBG_VALID;
memset(child->thread.dbr, 0,
sizeof(child->thread.dbr));
memset(child->thread.ibr, 0,
sizeof(child->thread.ibr));
}
ptr += regnum;
if ((regnum & 1) && write_access) {
/* don't let the user set kernel-level breakpoints: */
*ptr = *data & ~(7UL << 56);
return 0;
}
}
if (write_access)
*ptr = *data;
else
*data = *ptr;
return 0;
}
static long
ptrace_getregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
{
unsigned long psr, ec, lc, rnat, bsp, cfm, nat_bits, val;
struct unw_frame_info info;
struct ia64_fpreg fpval;
struct switch_stack *sw;
struct pt_regs *pt;
long ret, retval = 0;
char nat = 0;
int i;
if (!access_ok(VERIFY_WRITE, ppr, sizeof(struct pt_all_user_regs)))
return -EIO;
pt = task_pt_regs(child);
sw = (struct switch_stack *) (child->thread.ksp + 16);
unw_init_from_blocked_task(&info, child);
if (unw_unwind_to_user(&info) < 0) {
return -EIO;
}
if (((unsigned long) ppr & 0x7) != 0) {
dprintk("ptrace:unaligned register address %p\n", ppr);
return -EIO;
}
if (access_uarea(child, PT_CR_IPSR, &psr, 0) < 0
|| access_uarea(child, PT_AR_EC, &ec, 0) < 0
|| access_uarea(child, PT_AR_LC, &lc, 0) < 0
|| access_uarea(child, PT_AR_RNAT, &rnat, 0) < 0
|| access_uarea(child, PT_AR_BSP, &bsp, 0) < 0
|| access_uarea(child, PT_CFM, &cfm, 0)
|| access_uarea(child, PT_NAT_BITS, &nat_bits, 0))
return -EIO;
/* control regs */
retval |= __put_user(pt->cr_iip, &ppr->cr_iip);
retval |= __put_user(psr, &ppr->cr_ipsr);
/* app regs */
retval |= __put_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
retval |= __put_user(pt->ar_rsc, &ppr->ar[PT_AUR_RSC]);
retval |= __put_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
retval |= __put_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
retval |= __put_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
retval |= __put_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);
retval |= __put_user(ec, &ppr->ar[PT_AUR_EC]);
retval |= __put_user(lc, &ppr->ar[PT_AUR_LC]);
retval |= __put_user(rnat, &ppr->ar[PT_AUR_RNAT]);
retval |= __put_user(bsp, &ppr->ar[PT_AUR_BSP]);
retval |= __put_user(cfm, &ppr->cfm);
/* gr1-gr3 */
retval |= __copy_to_user(&ppr->gr[1], &pt->r1, sizeof(long));
retval |= __copy_to_user(&ppr->gr[2], &pt->r2, sizeof(long) *2);
/* gr4-gr7 */
for (i = 4; i < 8; i++) {
if (unw_access_gr(&info, i, &val, &nat, 0) < 0)
return -EIO;
retval |= __put_user(val, &ppr->gr[i]);
}
/* gr8-gr11 */
retval |= __copy_to_user(&ppr->gr[8], &pt->r8, sizeof(long) * 4);
/* gr12-gr15 */
retval |= __copy_to_user(&ppr->gr[12], &pt->r12, sizeof(long) * 2);
retval |= __copy_to_user(&ppr->gr[14], &pt->r14, sizeof(long));
retval |= __copy_to_user(&ppr->gr[15], &pt->r15, sizeof(long));
/* gr16-gr31 */
retval |= __copy_to_user(&ppr->gr[16], &pt->r16, sizeof(long) * 16);
/* b0 */
retval |= __put_user(pt->b0, &ppr->br[0]);
/* b1-b5 */
for (i = 1; i < 6; i++) {
if (unw_access_br(&info, i, &val, 0) < 0)
return -EIO;
__put_user(val, &ppr->br[i]);
}
/* b6-b7 */
retval |= __put_user(pt->b6, &ppr->br[6]);
retval |= __put_user(pt->b7, &ppr->br[7]);
/* fr2-fr5 */
for (i = 2; i < 6; i++) {
if (unw_get_fr(&info, i, &fpval) < 0)
return -EIO;
retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
}
/* fr6-fr11 */
retval |= __copy_to_user(&ppr->fr[6], &pt->f6,
sizeof(struct ia64_fpreg) * 6);
/* fp scratch regs(12-15) */
retval |= __copy_to_user(&ppr->fr[12], &sw->f12,
sizeof(struct ia64_fpreg) * 4);
/* fr16-fr31 */
for (i = 16; i < 32; i++) {
if (unw_get_fr(&info, i, &fpval) < 0)
return -EIO;
retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
}
/* fph */
ia64_flush_fph(child);
retval |= __copy_to_user(&ppr->fr[32], &child->thread.fph,
sizeof(ppr->fr[32]) * 96);
/* preds */
retval |= __put_user(pt->pr, &ppr->pr);
/* nat bits */
retval |= __put_user(nat_bits, &ppr->nat);
ret = retval ? -EIO : 0;
return ret;
}
static long
ptrace_setregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
{
unsigned long psr, rsc, ec, lc, rnat, bsp, cfm, nat_bits, val = 0;
struct unw_frame_info info;
struct switch_stack *sw;
struct ia64_fpreg fpval;
struct pt_regs *pt;
long ret, retval = 0;
int i;
memset(&fpval, 0, sizeof(fpval));
if (!access_ok(VERIFY_READ, ppr, sizeof(struct pt_all_user_regs)))
return -EIO;
pt = task_pt_regs(child);
sw = (struct switch_stack *) (child->thread.ksp + 16);
unw_init_from_blocked_task(&info, child);
if (unw_unwind_to_user(&info) < 0) {
return -EIO;
}
if (((unsigned long) ppr & 0x7) != 0) {
dprintk("ptrace:unaligned register address %p\n", ppr);
return -EIO;
}
/* control regs */
retval |= __get_user(pt->cr_iip, &ppr->cr_iip);
retval |= __get_user(psr, &ppr->cr_ipsr);
/* app regs */
retval |= __get_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
retval |= __get_user(rsc, &ppr->ar[PT_AUR_RSC]);
retval |= __get_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
retval |= __get_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
retval |= __get_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
retval |= __get_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);
retval |= __get_user(ec, &ppr->ar[PT_AUR_EC]);
retval |= __get_user(lc, &ppr->ar[PT_AUR_LC]);
retval |= __get_user(rnat, &ppr->ar[PT_AUR_RNAT]);
retval |= __get_user(bsp, &ppr->ar[PT_AUR_BSP]);
retval |= __get_user(cfm, &ppr->cfm);
/* gr1-gr3 */
retval |= __copy_from_user(&pt->r1, &ppr->gr[1], sizeof(long));
retval |= __copy_from_user(&pt->r2, &ppr->gr[2], sizeof(long) * 2);
/* gr4-gr7 */
for (i = 4; i < 8; i++) {
retval |= __get_user(val, &ppr->gr[i]);
/* NaT bit will be set via PT_NAT_BITS: */
if (unw_set_gr(&info, i, val, 0) < 0)
return -EIO;
}
/* gr8-gr11 */
retval |= __copy_from_user(&pt->r8, &ppr->gr[8], sizeof(long) * 4);
/* gr12-gr15 */
retval |= __copy_from_user(&pt->r12, &ppr->gr[12], sizeof(long) * 2);
retval |= __copy_from_user(&pt->r14, &ppr->gr[14], sizeof(long));
retval |= __copy_from_user(&pt->r15, &ppr->gr[15], sizeof(long));
/* gr16-gr31 */
retval |= __copy_from_user(&pt->r16, &ppr->gr[16], sizeof(long) * 16);
/* b0 */
retval |= __get_user(pt->b0, &ppr->br[0]);
/* b1-b5 */
for (i = 1; i < 6; i++) {
retval |= __get_user(val, &ppr->br[i]);
unw_set_br(&info, i, val);
}
/* b6-b7 */
retval |= __get_user(pt->b6, &ppr->br[6]);
retval |= __get_user(pt->b7, &ppr->br[7]);
/* fr2-fr5 */
for (i = 2; i < 6; i++) {
retval |= __copy_from_user(&fpval, &ppr->fr[i], sizeof(fpval));
if (unw_set_fr(&info, i, fpval) < 0)
return -EIO;
}
/* fr6-fr11 */
retval |= __copy_from_user(&pt->f6, &ppr->fr[6],
sizeof(ppr->fr[6]) * 6);
/* fp scratch regs(12-15) */
retval |= __copy_from_user(&sw->f12, &ppr->fr[12],
sizeof(ppr->fr[12]) * 4);
/* fr16-fr31 */
for (i = 16; i < 32; i++) {
retval |= __copy_from_user(&fpval, &ppr->fr[i],
sizeof(fpval));
if (unw_set_fr(&info, i, fpval) < 0)
return -EIO;
}
/* fph */
ia64_sync_fph(child);
retval |= __copy_from_user(&child->thread.fph, &ppr->fr[32],
sizeof(ppr->fr[32]) * 96);
/* preds */
retval |= __get_user(pt->pr, &ppr->pr);
/* nat bits */
retval |= __get_user(nat_bits, &ppr->nat);
retval |= access_uarea(child, PT_CR_IPSR, &psr, 1);
retval |= access_uarea(child, PT_AR_RSC, &rsc, 1);
retval |= access_uarea(child, PT_AR_EC, &ec, 1);
retval |= access_uarea(child, PT_AR_LC, &lc, 1);
retval |= access_uarea(child, PT_AR_RNAT, &rnat, 1);
retval |= access_uarea(child, PT_AR_BSP, &bsp, 1);
retval |= access_uarea(child, PT_CFM, &cfm, 1);
retval |= access_uarea(child, PT_NAT_BITS, &nat_bits, 1);
ret = retval ? -EIO : 0;
return ret;
}
/*
* Called by kernel/ptrace.c when detaching..
*
* Make sure the single step bit is not set.
*/
void
ptrace_disable (struct task_struct *child)
{
struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
/* make sure the single step/taken-branch trap bits are not set: */
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
child_psr->ss = 0;
child_psr->tb = 0;
}
asmlinkage long
sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data)
{
struct pt_regs *pt;
unsigned long urbs_end, peek_or_poke;
struct task_struct *child;
struct switch_stack *sw;
long ret;
struct unw_frame_info info;
lock_kernel();
ret = -EPERM;
if (request == PTRACE_TRACEME) {
ret = ptrace_traceme();
goto out;
}
peek_or_poke = (request == PTRACE_PEEKTEXT
|| request == PTRACE_PEEKDATA
|| request == PTRACE_POKETEXT
|| request == PTRACE_POKEDATA);
ret = -ESRCH;
read_lock(&tasklist_lock);
{
child = find_task_by_pid(pid);
if (child) {
if (peek_or_poke)
child = find_thread_for_addr(child, addr);
get_task_struct(child);
}
}
read_unlock(&tasklist_lock);
if (!child)
goto out;
ret = -EPERM;
if (pid == 1) /* no messing around with init! */
goto out_tsk;
if (request == PTRACE_ATTACH) {
ret = ptrace_attach(child);
if (!ret)
arch_ptrace_attach(child);
goto out_tsk;
}
ret = ptrace_check_attach(child, request == PTRACE_KILL);
if (ret < 0)
goto out_tsk;
pt = task_pt_regs(child);
sw = (struct switch_stack *) (child->thread.ksp + 16);
switch (request) {
case PTRACE_PEEKTEXT:
case PTRACE_PEEKDATA:
/* read word at location addr */
urbs_end = ia64_get_user_rbs_end(child, pt, NULL);
ret = ia64_peek(child, sw, urbs_end, addr, &data);
if (ret == 0) {
ret = data;
/* ensure "ret" is not mistaken as an error code: */
force_successful_syscall_return();
}
goto out_tsk;
case PTRACE_POKETEXT:
case PTRACE_POKEDATA:
/* write the word at location addr */
urbs_end = ia64_get_user_rbs_end(child, pt, NULL);
ret = ia64_poke(child, sw, urbs_end, addr, data);
/* Make sure user RBS has the latest data */
unw_init_from_blocked_task(&info, child);
do_sync_rbs(&info, ia64_sync_user_rbs);
goto out_tsk;
case PTRACE_PEEKUSR:
/* read the word at addr in the USER area */
if (access_uarea(child, addr, &data, 0) < 0) {
ret = -EIO;
goto out_tsk;
}
ret = data;
/* ensure "ret" is not mistaken as an error code */
force_successful_syscall_return();
goto out_tsk;
case PTRACE_POKEUSR:
/* write the word at addr in the USER area */
if (access_uarea(child, addr, &data, 1) < 0) {
ret = -EIO;
goto out_tsk;
}
ret = 0;
goto out_tsk;
case PTRACE_OLD_GETSIGINFO:
/* for backwards-compatibility */
ret = ptrace_request(child, PTRACE_GETSIGINFO, addr, data);
goto out_tsk;
case PTRACE_OLD_SETSIGINFO:
/* for backwards-compatibility */
ret = ptrace_request(child, PTRACE_SETSIGINFO, addr, data);
goto out_tsk;
case PTRACE_SYSCALL:
/* continue and stop at next (return from) syscall */
case PTRACE_CONT:
/* restart after signal. */
ret = -EIO;
if (!valid_signal(data))
goto out_tsk;
if (request == PTRACE_SYSCALL)
set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
else
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
child->exit_code = data;
/*
* Make sure the single step/taken-branch trap bits
* are not set:
*/
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
ia64_psr(pt)->ss = 0;
ia64_psr(pt)->tb = 0;
wake_up_process(child);
ret = 0;
goto out_tsk;
case PTRACE_KILL:
/*
* Make the child exit. Best I can do is send it a
* sigkill. Perhaps it should be put in the status
* that it wants to exit.
*/
if (child->exit_state == EXIT_ZOMBIE)
/* already dead */
goto out_tsk;
child->exit_code = SIGKILL;
ptrace_disable(child);
wake_up_process(child);
ret = 0;
goto out_tsk;
case PTRACE_SINGLESTEP:
/* let child execute for one instruction */
case PTRACE_SINGLEBLOCK:
ret = -EIO;
if (!valid_signal(data))
goto out_tsk;
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
set_tsk_thread_flag(child, TIF_SINGLESTEP);
if (request == PTRACE_SINGLESTEP) {
ia64_psr(pt)->ss = 1;
} else {
ia64_psr(pt)->tb = 1;
}
child->exit_code = data;
/* give it a chance to run. */
wake_up_process(child);
ret = 0;
goto out_tsk;
case PTRACE_DETACH:
/* detach a process that was attached. */
ret = ptrace_detach(child, data);
goto out_tsk;
case PTRACE_GETREGS:
ret = ptrace_getregs(child,
(struct pt_all_user_regs __user *) data);
goto out_tsk;
case PTRACE_SETREGS:
ret = ptrace_setregs(child,
(struct pt_all_user_regs __user *) data);
goto out_tsk;
default:
ret = ptrace_request(child, request, addr, data);
goto out_tsk;
}
out_tsk:
put_task_struct(child);
out:
unlock_kernel();
return ret;
}
static void
syscall_trace (void)
{
/*
* The 0x80 provides a way for the tracing parent to
* distinguish between a syscall stop and SIGTRAP delivery.
*/
ptrace_notify(SIGTRAP
| ((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
/*
* This isn't the same as continuing with a signal, but it
* will do for normal use. strace only continues with a
* signal if the stopping signal is not SIGTRAP. -brl
*/
if (current->exit_code) {
send_sig(current->exit_code, current, 1);
current->exit_code = 0;
}
}
/* "asmlinkage" so the input arguments are preserved... */
asmlinkage void
syscall_trace_enter (long arg0, long arg1, long arg2, long arg3,
long arg4, long arg5, long arg6, long arg7,
struct pt_regs regs)
{
if (test_thread_flag(TIF_SYSCALL_TRACE)
&& (current->ptrace & PT_PTRACED))
syscall_trace();
/* copy user rbs to kernel rbs */
if (test_thread_flag(TIF_RESTORE_RSE))
ia64_sync_krbs();
if (unlikely(current->audit_context)) {
long syscall;
int arch;
if (IS_IA32_PROCESS(&regs)) {
syscall = regs.r1;
arch = AUDIT_ARCH_I386;
} else {
syscall = regs.r15;
arch = AUDIT_ARCH_IA64;
}
audit_syscall_entry(arch, syscall, arg0, arg1, arg2, arg3);
}
}
/* "asmlinkage" so the input arguments are preserved... */
asmlinkage void
syscall_trace_leave (long arg0, long arg1, long arg2, long arg3,
long arg4, long arg5, long arg6, long arg7,
struct pt_regs regs)
{
if (unlikely(current->audit_context)) {
int success = AUDITSC_RESULT(regs.r10);
long result = regs.r8;
if (success != AUDITSC_SUCCESS)
result = -result;
audit_syscall_exit(success, result);
}
if ((test_thread_flag(TIF_SYSCALL_TRACE)
|| test_thread_flag(TIF_SINGLESTEP))
&& (current->ptrace & PT_PTRACED))
syscall_trace();
/* copy user rbs to kernel rbs */
if (test_thread_flag(TIF_RESTORE_RSE))
ia64_sync_krbs();
}
Reference in New Issue View Git Blame Copy Permalink