- 根目录:
- arch
- xtensa
- kernel
- ptrace.c
// TODO some minor issues
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2007 Tensilica Inc.
*
* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
* Chris Zankel <chris@zankel.net>
* Scott Foehner<sfoehner@yahoo.com>,
* Kevin Chea
* Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca>
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/smp.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/uaccess.h>
#include <asm/ptrace.h>
#include <asm/elf.h>
#include <asm/coprocessor.h>
void user_enable_single_step(struct task_struct *child)
{
child->ptrace |= PT_SINGLESTEP;
}
void user_disable_single_step(struct task_struct *child)
{
child->ptrace &= ~PT_SINGLESTEP;
}
/*
* Called by kernel/ptrace.c when detaching to disable single stepping.
*/
void ptrace_disable(struct task_struct *child)
{
/* Nothing to do.. */
}
int ptrace_getregs(struct task_struct *child, void __user *uregs)
{
struct pt_regs *regs = task_pt_regs(child);
xtensa_gregset_t __user *gregset = uregs;
unsigned long wb = regs->windowbase;
int i;
if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
return -EIO;
__put_user(regs->pc, &gregset->pc);
__put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps);
__put_user(regs->lbeg, &gregset->lbeg);
__put_user(regs->lend, &gregset->lend);
__put_user(regs->lcount, &gregset->lcount);
__put_user(regs->windowstart, &gregset->windowstart);
__put_user(regs->windowbase, &gregset->windowbase);
__put_user(regs->threadptr, &gregset->threadptr);
for (i = 0; i < XCHAL_NUM_AREGS; i++)
__put_user(regs->areg[i],
gregset->a + ((wb * 4 + i) % XCHAL_NUM_AREGS));
return 0;
}
int ptrace_setregs(struct task_struct *child, void __user *uregs)
{
struct pt_regs *regs = task_pt_regs(child);
xtensa_gregset_t *gregset = uregs;
const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK;
unsigned long ps;
unsigned long wb, ws;
if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
return -EIO;
__get_user(regs->pc, &gregset->pc);
__get_user(ps, &gregset->ps);
__get_user(regs->lbeg, &gregset->lbeg);
__get_user(regs->lend, &gregset->lend);
__get_user(regs->lcount, &gregset->lcount);
__get_user(ws, &gregset->windowstart);
__get_user(wb, &gregset->windowbase);
__get_user(regs->threadptr, &gregset->threadptr);
regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT);
if (wb >= XCHAL_NUM_AREGS / 4)
return -EFAULT;
if (wb != regs->windowbase || ws != regs->windowstart) {
unsigned long rotws, wmask;
rotws = (((ws | (ws << WSBITS)) >> wb) &
((1 << WSBITS) - 1)) & ~1;
wmask = ((rotws ? WSBITS + 1 - ffs(rotws) : 0) << 4) |
(rotws & 0xF) | 1;
regs->windowbase = wb;
regs->windowstart = ws;
regs->wmask = wmask;
}
if (wb != 0 && __copy_from_user(regs->areg + XCHAL_NUM_AREGS - wb * 4,
gregset->a, wb * 16))
return -EFAULT;
if (__copy_from_user(regs->areg, gregset->a + wb * 4,
(WSBITS - wb) * 16))
return -EFAULT;
return 0;
}
int ptrace_getxregs(struct task_struct *child, void __user *uregs)
{
struct pt_regs *regs = task_pt_regs(child);
struct thread_info *ti = task_thread_info(child);
elf_xtregs_t __user *xtregs = uregs;
int ret = 0;
if (!access_ok(VERIFY_WRITE, uregs, sizeof(elf_xtregs_t)))
return -EIO;
#if XTENSA_HAVE_COPROCESSORS
/* Flush all coprocessor registers to memory. */
coprocessor_flush_all(ti);
ret |= __copy_to_user(&xtregs->cp0, &ti->xtregs_cp,
sizeof(xtregs_coprocessor_t));
#endif
ret |= __copy_to_user(&xtregs->opt, ®s->xtregs_opt,
sizeof(xtregs->opt));
ret |= __copy_to_user(&xtregs->user,&ti->xtregs_user,
sizeof(xtregs->user));
return ret ? -EFAULT : 0;
}
int ptrace_setxregs(struct task_struct *child, void __user *uregs)
{
struct thread_info *ti = task_thread_info(child);
struct pt_regs *regs = task_pt_regs(child);
elf_xtregs_t *xtregs = uregs;
int ret = 0;
if (!access_ok(VERIFY_READ, uregs, sizeof(elf_xtregs_t)))
return -EFAULT;
#if XTENSA_HAVE_COPROCESSORS
/* Flush all coprocessors before we overwrite them. */
coprocessor_flush_all(ti);
coprocessor_release_all(ti);
ret |= __copy_from_user(&ti->xtregs_cp, &xtregs->cp0,
sizeof(xtregs_coprocessor_t));
#endif
ret |= __copy_from_user(®s->xtregs_opt, &xtregs->opt,
sizeof(xtregs->opt));
ret |= __copy_from_user(&ti->xtregs_user, &xtregs->user,
sizeof(xtregs->user));
return ret ? -EFAULT : 0;
}
int ptrace_peekusr(struct task_struct *child, long regno, long __user *ret)
{
struct pt_regs *regs;
unsigned long tmp;
regs = task_pt_regs(child);
tmp = 0; /* Default return value. */
switch(regno) {
case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
tmp = regs->areg[regno - REG_AR_BASE];
break;
case REG_A_BASE ... REG_A_BASE + 15:
tmp = regs->areg[regno - REG_A_BASE];
break;
case REG_PC:
tmp = regs->pc;
break;
case REG_PS:
/* Note: PS.EXCM is not set while user task is running;
* its being set in regs is for exception handling
* convenience. */
tmp = (regs->ps & ~(1 << PS_EXCM_BIT));
break;
case REG_WB:
break; /* tmp = 0 */
case REG_WS:
{
unsigned long wb = regs->windowbase;
unsigned long ws = regs->windowstart;
tmp = ((ws>>wb) | (ws<<(WSBITS-wb))) & ((1<<WSBITS)-1);
break;
}
case REG_LBEG:
tmp = regs->lbeg;
break;
case REG_LEND:
tmp = regs->lend;
break;
case REG_LCOUNT:
tmp = regs->lcount;
break;
case REG_SAR:
tmp = regs->sar;
break;
case SYSCALL_NR:
tmp = regs->syscall;
break;
default:
return -EIO;
}
return put_user(tmp, ret);
}
int ptrace_pokeusr(struct task_struct *child, long regno, long val)
{
struct pt_regs *regs;
regs = task_pt_regs(child);
switch (regno) {
case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
regs->areg[regno - REG_AR_BASE] = val;
break;
case REG_A_BASE ... REG_A_BASE + 15:
regs->areg[regno - REG_A_BASE] = val;
break;
case REG_PC:
regs->pc = val;
break;
case SYSCALL_NR:
regs->syscall = val;
break;
default:
return -EIO;
}
return 0;
}
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
int ret = -EPERM;
void __user *datap = (void __user *) data;
switch (request) {
case PTRACE_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA:
ret = generic_ptrace_peekdata(child, addr, data);
break;
case PTRACE_PEEKUSR: /* read register specified by addr. */
ret = ptrace_peekusr(child, addr, datap);
break;
case PTRACE_POKETEXT: /* write the word at location addr. */
case PTRACE_POKEDATA:
ret = generic_ptrace_pokedata(child, addr, data);
break;
case PTRACE_POKEUSR: /* write register specified by addr. */
ret = ptrace_pokeusr(child, addr, data);
break;
case PTRACE_GETREGS:
ret = ptrace_getregs(child, datap);
break;
case PTRACE_SETREGS:
ret = ptrace_setregs(child, datap);
break;
case PTRACE_GETXTREGS:
ret = ptrace_getxregs(child, datap);
break;
case PTRACE_SETXTREGS:
ret = ptrace_setxregs(child, datap);
break;
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
void do_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;
}
}
void do_syscall_trace_enter(struct pt_regs *regs)
{
if (test_thread_flag(TIF_SYSCALL_TRACE)
&& (current->ptrace & PT_PTRACED))
do_syscall_trace();
#if 0
audit_syscall_entry(...);
#endif
}
void do_syscall_trace_leave(struct pt_regs *regs)
{
if ((test_thread_flag(TIF_SYSCALL_TRACE))
&& (current->ptrace & PT_PTRACED))
do_syscall_trace();
}