x86: x86-32 thread_struct.debugreg

This replaces the debugreg[7] member of thread_struct with individual
members debugreg0, etc.  This saves two words for the dummies 4 and 5,
and harmonizes the code between 32 and 64.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Roland McGrath 2008-01-30 13:30:59 +01:00 committed by Ingo Molnar
parent d277fb89df
commit 0f5340933f
6 changed files with 61 additions and 28 deletions

View File

@ -445,7 +445,12 @@ void flush_thread(void)
{
struct task_struct *tsk = current;
memset(tsk->thread.debugreg, 0, sizeof(unsigned long)*8);
tsk->thread.debugreg0 = 0;
tsk->thread.debugreg1 = 0;
tsk->thread.debugreg2 = 0;
tsk->thread.debugreg3 = 0;
tsk->thread.debugreg6 = 0;
tsk->thread.debugreg7 = 0;
memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
clear_tsk_thread_flag(tsk, TIF_DEBUG);
/*
@ -522,7 +527,6 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
*/
void dump_thread(struct pt_regs * regs, struct user * dump)
{
int i;
u16 gs;
/* changed the size calculations - should hopefully work better. lbt */
@ -533,8 +537,14 @@ void dump_thread(struct pt_regs * regs, struct user * dump)
dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
dump->u_dsize -= dump->u_tsize;
dump->u_ssize = 0;
for (i = 0; i < 8; i++)
dump->u_debugreg[i] = current->thread.debugreg[i];
dump->u_debugreg[0] = current->thread.debugreg0;
dump->u_debugreg[1] = current->thread.debugreg1;
dump->u_debugreg[2] = current->thread.debugreg2;
dump->u_debugreg[3] = current->thread.debugreg3;
dump->u_debugreg[4] = 0;
dump->u_debugreg[5] = 0;
dump->u_debugreg[6] = current->thread.debugreg6;
dump->u_debugreg[7] = current->thread.debugreg7;
if (dump->start_stack < TASK_SIZE)
dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
@ -612,13 +622,13 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
wrmsr(MSR_IA32_DEBUGCTLMSR, next->debugctlmsr, 0);
if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
set_debugreg(next->debugreg[0], 0);
set_debugreg(next->debugreg[1], 1);
set_debugreg(next->debugreg[2], 2);
set_debugreg(next->debugreg[3], 3);
set_debugreg(next->debugreg0, 0);
set_debugreg(next->debugreg1, 1);
set_debugreg(next->debugreg2, 2);
set_debugreg(next->debugreg3, 3);
/* no 4 and 5 */
set_debugreg(next->debugreg[6], 6);
set_debugreg(next->debugreg[7], 7);
set_debugreg(next->debugreg6, 6);
set_debugreg(next->debugreg7, 7);
}
#ifdef CONFIG_SECCOMP
@ -869,4 +879,3 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
unsigned long range_end = mm->brk + 0x02000000;
return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
}

View File

@ -133,19 +133,39 @@ static unsigned long getreg(struct task_struct *child, unsigned long regno)
*/
static unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
{
return child->thread.debugreg[n];
switch (n) {
case 0: return child->thread.debugreg0;
case 1: return child->thread.debugreg1;
case 2: return child->thread.debugreg2;
case 3: return child->thread.debugreg3;
case 6: return child->thread.debugreg6;
case 7: return child->thread.debugreg7;
}
return 0;
}
static int ptrace_set_debugreg(struct task_struct *child,
int n, unsigned long data)
{
int i;
if (unlikely(n == 4 || n == 5))
return -EIO;
if (n < 4 && unlikely(data >= TASK_SIZE - 3))
return -EIO;
if (n == 7) {
switch (n) {
case 0: child->thread.debugreg0 = data; break;
case 1: child->thread.debugreg1 = data; break;
case 2: child->thread.debugreg2 = data; break;
case 3: child->thread.debugreg3 = data; break;
case 6:
child->thread.debugreg6 = data;
break;
case 7:
/*
* Sanity-check data. Take one half-byte at once with
* check = (val >> (16 + 4*i)) & 0xf. It contains the
@ -176,19 +196,18 @@ static int ptrace_set_debugreg(struct task_struct *child,
* 64-bit kernel), so the x86_64 mask value is 0x5454.
* See the AMD manual no. 24593 (AMD64 System Programming)
*/
int i;
data &= ~DR_CONTROL_RESERVED;
for (i = 0; i < 4; i++)
if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
return -EIO;
child->thread.debugreg7 = data;
if (data)
set_tsk_thread_flag(child, TIF_DEBUG);
else
clear_tsk_thread_flag(child, TIF_DEBUG);
break;
}
child->thread.debugreg[n] = data;
return 0;
}

View File

@ -605,8 +605,8 @@ static void fastcall do_signal(struct pt_regs *regs)
* have been cleared if the watchpoint triggered
* inside the kernel.
*/
if (unlikely(current->thread.debugreg[7]))
set_debugreg(current->thread.debugreg[7], 7);
if (unlikely(current->thread.debugreg7))
set_debugreg(current->thread.debugreg7, 7);
/* Whee! Actually deliver the signal. */
if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {

View File

@ -852,7 +852,7 @@ fastcall void __kprobes do_debug(struct pt_regs * regs, long error_code)
/* Mask out spurious debug traps due to lazy DR7 setting */
if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
if (!tsk->thread.debugreg[7])
if (!tsk->thread.debugreg7)
goto clear_dr7;
}
@ -860,7 +860,7 @@ fastcall void __kprobes do_debug(struct pt_regs * regs, long error_code)
goto debug_vm86;
/* Save debug status register where ptrace can see it */
tsk->thread.debugreg[6] = condition;
tsk->thread.debugreg6 = condition;
/*
* Single-stepping through TF: make sure we ignore any events in

View File

@ -74,14 +74,14 @@ static void fix_processor_context(void)
/*
* Now maybe reload the debug registers
*/
if (current->thread.debugreg[7]){
set_debugreg(current->thread.debugreg[0], 0);
set_debugreg(current->thread.debugreg[1], 1);
set_debugreg(current->thread.debugreg[2], 2);
set_debugreg(current->thread.debugreg[3], 3);
if (current->thread.debugreg7) {
set_debugreg(current->thread.debugreg0, 0);
set_debugreg(current->thread.debugreg1, 1);
set_debugreg(current->thread.debugreg2, 2);
set_debugreg(current->thread.debugreg3, 3);
/* no 4 and 5 */
set_debugreg(current->thread.debugreg[6], 6);
set_debugreg(current->thread.debugreg[7], 7);
set_debugreg(current->thread.debugreg6, 6);
set_debugreg(current->thread.debugreg7, 7);
}
}

View File

@ -353,7 +353,12 @@ struct thread_struct {
unsigned long fs;
unsigned long gs;
/* Hardware debugging registers */
unsigned long debugreg[8]; /* %%db0-7 debug registers */
unsigned long debugreg0;
unsigned long debugreg1;
unsigned long debugreg2;
unsigned long debugreg3;
unsigned long debugreg6;
unsigned long debugreg7;
/* fault info */
unsigned long cr2, trap_no, error_code;
/* floating point info */