x86: single_step moved
This moves the single-step support code from ptrace_64.c into a new file step.c, verbatim. This paves the way for consolidating this code between 64-bit and 32-bit versions. 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:
Родитель
7f232343e0
Коммит
fa1e03eae2
|
@ -13,6 +13,8 @@ obj-y := process_64.o signal_64.o entry_64.o traps_64.o irq_64.o \
|
||||||
pci-dma_64.o pci-nommu_64.o alternative.o hpet.o tsc_64.o bugs_64.o \
|
pci-dma_64.o pci-nommu_64.o alternative.o hpet.o tsc_64.o bugs_64.o \
|
||||||
i8253.o io_delay.o rtc.o
|
i8253.o io_delay.o rtc.o
|
||||||
|
|
||||||
|
obj-y += step.o
|
||||||
|
|
||||||
obj-$(CONFIG_IA32_EMULATION) += tls.o
|
obj-$(CONFIG_IA32_EMULATION) += tls.o
|
||||||
obj-$(CONFIG_STACKTRACE) += stacktrace.o
|
obj-$(CONFIG_STACKTRACE) += stacktrace.o
|
||||||
obj-y += cpu/
|
obj-y += cpu/
|
||||||
|
|
|
@ -80,140 +80,6 @@ static inline long put_stack_long(struct task_struct *task, int offset,
|
||||||
return 0;
|
return 0;
|
||||||
}
|
}
|
||||||
|
|
||||||
#define LDT_SEGMENT 4
|
|
||||||
|
|
||||||
unsigned long convert_rip_to_linear(struct task_struct *child, struct pt_regs *regs)
|
|
||||||
{
|
|
||||||
unsigned long addr, seg;
|
|
||||||
|
|
||||||
addr = regs->rip;
|
|
||||||
seg = regs->cs & 0xffff;
|
|
||||||
|
|
||||||
/*
|
|
||||||
* We'll assume that the code segments in the GDT
|
|
||||||
* are all zero-based. That is largely true: the
|
|
||||||
* TLS segments are used for data, and the PNPBIOS
|
|
||||||
* and APM bios ones we just ignore here.
|
|
||||||
*/
|
|
||||||
if (seg & LDT_SEGMENT) {
|
|
||||||
u32 *desc;
|
|
||||||
unsigned long base;
|
|
||||||
|
|
||||||
seg &= ~7UL;
|
|
||||||
|
|
||||||
mutex_lock(&child->mm->context.lock);
|
|
||||||
if (unlikely((seg >> 3) >= child->mm->context.size))
|
|
||||||
addr = -1L; /* bogus selector, access would fault */
|
|
||||||
else {
|
|
||||||
desc = child->mm->context.ldt + seg;
|
|
||||||
base = ((desc[0] >> 16) |
|
|
||||||
((desc[1] & 0xff) << 16) |
|
|
||||||
(desc[1] & 0xff000000));
|
|
||||||
|
|
||||||
/* 16-bit code segment? */
|
|
||||||
if (!((desc[1] >> 22) & 1))
|
|
||||||
addr &= 0xffff;
|
|
||||||
addr += base;
|
|
||||||
}
|
|
||||||
mutex_unlock(&child->mm->context.lock);
|
|
||||||
}
|
|
||||||
|
|
||||||
return addr;
|
|
||||||
}
|
|
||||||
|
|
||||||
static int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)
|
|
||||||
{
|
|
||||||
int i, copied;
|
|
||||||
unsigned char opcode[15];
|
|
||||||
unsigned long addr = convert_rip_to_linear(child, regs);
|
|
||||||
|
|
||||||
copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0);
|
|
||||||
for (i = 0; i < copied; i++) {
|
|
||||||
switch (opcode[i]) {
|
|
||||||
/* popf and iret */
|
|
||||||
case 0x9d: case 0xcf:
|
|
||||||
return 1;
|
|
||||||
|
|
||||||
/* CHECKME: 64 65 */
|
|
||||||
|
|
||||||
/* opcode and address size prefixes */
|
|
||||||
case 0x66: case 0x67:
|
|
||||||
continue;
|
|
||||||
/* irrelevant prefixes (segment overrides and repeats) */
|
|
||||||
case 0x26: case 0x2e:
|
|
||||||
case 0x36: case 0x3e:
|
|
||||||
case 0x64: case 0x65:
|
|
||||||
case 0xf2: case 0xf3:
|
|
||||||
continue;
|
|
||||||
|
|
||||||
case 0x40 ... 0x4f:
|
|
||||||
if (regs->cs != __USER_CS)
|
|
||||||
/* 32-bit mode: register increment */
|
|
||||||
return 0;
|
|
||||||
/* 64-bit mode: REX prefix */
|
|
||||||
continue;
|
|
||||||
|
|
||||||
/* CHECKME: f2, f3 */
|
|
||||||
|
|
||||||
/*
|
|
||||||
* pushf: NOTE! We should probably not let
|
|
||||||
* the user see the TF bit being set. But
|
|
||||||
* it's more pain than it's worth to avoid
|
|
||||||
* it, and a debugger could emulate this
|
|
||||||
* all in user space if it _really_ cares.
|
|
||||||
*/
|
|
||||||
case 0x9c:
|
|
||||||
default:
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
|
|
||||||
void user_enable_single_step(struct task_struct *child)
|
|
||||||
{
|
|
||||||
struct pt_regs *regs = task_pt_regs(child);
|
|
||||||
|
|
||||||
/*
|
|
||||||
* Always set TIF_SINGLESTEP - this guarantees that
|
|
||||||
* we single-step system calls etc.. This will also
|
|
||||||
* cause us to set TF when returning to user mode.
|
|
||||||
*/
|
|
||||||
set_tsk_thread_flag(child, TIF_SINGLESTEP);
|
|
||||||
|
|
||||||
/*
|
|
||||||
* If TF was already set, don't do anything else
|
|
||||||
*/
|
|
||||||
if (regs->eflags & X86_EFLAGS_TF)
|
|
||||||
return;
|
|
||||||
|
|
||||||
/* Set TF on the kernel stack.. */
|
|
||||||
regs->eflags |= X86_EFLAGS_TF;
|
|
||||||
|
|
||||||
/*
|
|
||||||
* ..but if TF is changed by the instruction we will trace,
|
|
||||||
* don't mark it as being "us" that set it, so that we
|
|
||||||
* won't clear it by hand later.
|
|
||||||
*/
|
|
||||||
if (is_setting_trap_flag(child, regs))
|
|
||||||
return;
|
|
||||||
|
|
||||||
child->ptrace |= PT_DTRACE;
|
|
||||||
}
|
|
||||||
|
|
||||||
void user_disable_single_step(struct task_struct *child)
|
|
||||||
{
|
|
||||||
/* Always clear TIF_SINGLESTEP... */
|
|
||||||
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
|
|
||||||
|
|
||||||
/* But touch TF only if it was set by us.. */
|
|
||||||
if (child->ptrace & PT_DTRACE) {
|
|
||||||
struct pt_regs *regs = task_pt_regs(child);
|
|
||||||
regs->eflags &= ~X86_EFLAGS_TF;
|
|
||||||
child->ptrace &= ~PT_DTRACE;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* Called by kernel/ptrace.c when detaching..
|
* Called by kernel/ptrace.c when detaching..
|
||||||
*
|
*
|
||||||
|
|
|
@ -0,0 +1,140 @@
|
||||||
|
/*
|
||||||
|
* x86 single-step support code, common to 32-bit and 64-bit.
|
||||||
|
*/
|
||||||
|
#include <linux/sched.h>
|
||||||
|
#include <linux/mm.h>
|
||||||
|
#include <linux/ptrace.h>
|
||||||
|
|
||||||
|
#define LDT_SEGMENT 4
|
||||||
|
|
||||||
|
unsigned long convert_rip_to_linear(struct task_struct *child, struct pt_regs *regs)
|
||||||
|
{
|
||||||
|
unsigned long addr, seg;
|
||||||
|
|
||||||
|
addr = regs->rip;
|
||||||
|
seg = regs->cs & 0xffff;
|
||||||
|
|
||||||
|
/*
|
||||||
|
* We'll assume that the code segments in the GDT
|
||||||
|
* are all zero-based. That is largely true: the
|
||||||
|
* TLS segments are used for data, and the PNPBIOS
|
||||||
|
* and APM bios ones we just ignore here.
|
||||||
|
*/
|
||||||
|
if (seg & LDT_SEGMENT) {
|
||||||
|
u32 *desc;
|
||||||
|
unsigned long base;
|
||||||
|
|
||||||
|
seg &= ~7UL;
|
||||||
|
|
||||||
|
mutex_lock(&child->mm->context.lock);
|
||||||
|
if (unlikely((seg >> 3) >= child->mm->context.size))
|
||||||
|
addr = -1L; /* bogus selector, access would fault */
|
||||||
|
else {
|
||||||
|
desc = child->mm->context.ldt + seg;
|
||||||
|
base = ((desc[0] >> 16) |
|
||||||
|
((desc[1] & 0xff) << 16) |
|
||||||
|
(desc[1] & 0xff000000));
|
||||||
|
|
||||||
|
/* 16-bit code segment? */
|
||||||
|
if (!((desc[1] >> 22) & 1))
|
||||||
|
addr &= 0xffff;
|
||||||
|
addr += base;
|
||||||
|
}
|
||||||
|
mutex_unlock(&child->mm->context.lock);
|
||||||
|
}
|
||||||
|
|
||||||
|
return addr;
|
||||||
|
}
|
||||||
|
|
||||||
|
static int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)
|
||||||
|
{
|
||||||
|
int i, copied;
|
||||||
|
unsigned char opcode[15];
|
||||||
|
unsigned long addr = convert_rip_to_linear(child, regs);
|
||||||
|
|
||||||
|
copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0);
|
||||||
|
for (i = 0; i < copied; i++) {
|
||||||
|
switch (opcode[i]) {
|
||||||
|
/* popf and iret */
|
||||||
|
case 0x9d: case 0xcf:
|
||||||
|
return 1;
|
||||||
|
|
||||||
|
/* CHECKME: 64 65 */
|
||||||
|
|
||||||
|
/* opcode and address size prefixes */
|
||||||
|
case 0x66: case 0x67:
|
||||||
|
continue;
|
||||||
|
/* irrelevant prefixes (segment overrides and repeats) */
|
||||||
|
case 0x26: case 0x2e:
|
||||||
|
case 0x36: case 0x3e:
|
||||||
|
case 0x64: case 0x65:
|
||||||
|
case 0xf2: case 0xf3:
|
||||||
|
continue;
|
||||||
|
|
||||||
|
case 0x40 ... 0x4f:
|
||||||
|
if (regs->cs != __USER_CS)
|
||||||
|
/* 32-bit mode: register increment */
|
||||||
|
return 0;
|
||||||
|
/* 64-bit mode: REX prefix */
|
||||||
|
continue;
|
||||||
|
|
||||||
|
/* CHECKME: f2, f3 */
|
||||||
|
|
||||||
|
/*
|
||||||
|
* pushf: NOTE! We should probably not let
|
||||||
|
* the user see the TF bit being set. But
|
||||||
|
* it's more pain than it's worth to avoid
|
||||||
|
* it, and a debugger could emulate this
|
||||||
|
* all in user space if it _really_ cares.
|
||||||
|
*/
|
||||||
|
case 0x9c:
|
||||||
|
default:
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
void user_enable_single_step(struct task_struct *child)
|
||||||
|
{
|
||||||
|
struct pt_regs *regs = task_pt_regs(child);
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Always set TIF_SINGLESTEP - this guarantees that
|
||||||
|
* we single-step system calls etc.. This will also
|
||||||
|
* cause us to set TF when returning to user mode.
|
||||||
|
*/
|
||||||
|
set_tsk_thread_flag(child, TIF_SINGLESTEP);
|
||||||
|
|
||||||
|
/*
|
||||||
|
* If TF was already set, don't do anything else
|
||||||
|
*/
|
||||||
|
if (regs->eflags & X86_EFLAGS_TF)
|
||||||
|
return;
|
||||||
|
|
||||||
|
/* Set TF on the kernel stack.. */
|
||||||
|
regs->eflags |= X86_EFLAGS_TF;
|
||||||
|
|
||||||
|
/*
|
||||||
|
* ..but if TF is changed by the instruction we will trace,
|
||||||
|
* don't mark it as being "us" that set it, so that we
|
||||||
|
* won't clear it by hand later.
|
||||||
|
*/
|
||||||
|
if (is_setting_trap_flag(child, regs))
|
||||||
|
return;
|
||||||
|
|
||||||
|
child->ptrace |= PT_DTRACE;
|
||||||
|
}
|
||||||
|
|
||||||
|
void user_disable_single_step(struct task_struct *child)
|
||||||
|
{
|
||||||
|
/* Always clear TIF_SINGLESTEP... */
|
||||||
|
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
|
||||||
|
|
||||||
|
/* But touch TF only if it was set by us.. */
|
||||||
|
if (child->ptrace & PT_DTRACE) {
|
||||||
|
struct pt_regs *regs = task_pt_regs(child);
|
||||||
|
regs->eflags &= ~X86_EFLAGS_TF;
|
||||||
|
child->ptrace &= ~PT_DTRACE;
|
||||||
|
}
|
||||||
|
}
|
Загрузка…
Ссылка в новой задаче