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OpenCloudOS-Kernel/arch/x86/kernel/ptrace.c

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/* By Ross Biro 1/23/92 */
/*
* Pentium III FXSR, SSE support
* Gareth Hughes <gareth@valinux.com>, May 2000
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/ptrace.h>
#include <linux/regset.h>
#include <linux/tracehook.h>
#include <linux/user.h>
#include <linux/elf.h>
#include <linux/security.h>
#include <linux/audit.h>
#include <linux/seccomp.h>
#include <linux/signal.h>
#include <linux/perf_event.h>
#include <linux/hw_breakpoint.h>
#include <linux/rcupdate.h>
#include <linux/export.h>
#include <linux/context_tracking.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/fpu/internal.h>
#include <asm/debugreg.h>
#include <asm/ldt.h>
#include <asm/desc.h>
#include <asm/prctl.h>
#include <asm/proto.h>
#include <asm/hw_breakpoint.h>
#include <asm/traps.h>
#include "tls.h"
#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>
enum x86_regset {
REGSET_GENERAL,
REGSET_FP,
REGSET_XFP,
REGSET_IOPERM64 = REGSET_XFP,
REGSET_XSTATE,
REGSET_TLS,
REGSET_IOPERM32,
};
struct pt_regs_offset {
const char *name;
int offset;
};
#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
#define REG_OFFSET_END {.name = NULL, .offset = 0}
static const struct pt_regs_offset regoffset_table[] = {
#ifdef CONFIG_X86_64
REG_OFFSET_NAME(r15),
REG_OFFSET_NAME(r14),
REG_OFFSET_NAME(r13),
REG_OFFSET_NAME(r12),
REG_OFFSET_NAME(r11),
REG_OFFSET_NAME(r10),
REG_OFFSET_NAME(r9),
REG_OFFSET_NAME(r8),
#endif
REG_OFFSET_NAME(bx),
REG_OFFSET_NAME(cx),
REG_OFFSET_NAME(dx),
REG_OFFSET_NAME(si),
REG_OFFSET_NAME(di),
REG_OFFSET_NAME(bp),
REG_OFFSET_NAME(ax),
#ifdef CONFIG_X86_32
REG_OFFSET_NAME(ds),
REG_OFFSET_NAME(es),
REG_OFFSET_NAME(fs),
REG_OFFSET_NAME(gs),
#endif
REG_OFFSET_NAME(orig_ax),
REG_OFFSET_NAME(ip),
REG_OFFSET_NAME(cs),
REG_OFFSET_NAME(flags),
REG_OFFSET_NAME(sp),
REG_OFFSET_NAME(ss),
REG_OFFSET_END,
};
/**
* regs_query_register_offset() - query register offset from its name
* @name: the name of a register
*
* regs_query_register_offset() returns the offset of a register in struct
* pt_regs from its name. If the name is invalid, this returns -EINVAL;
*/
int regs_query_register_offset(const char *name)
{
const struct pt_regs_offset *roff;
for (roff = regoffset_table; roff->name != NULL; roff++)
if (!strcmp(roff->name, name))
return roff->offset;
return -EINVAL;
}
/**
* regs_query_register_name() - query register name from its offset
* @offset: the offset of a register in struct pt_regs.
*
* regs_query_register_name() returns the name of a register from its
* offset in struct pt_regs. If the @offset is invalid, this returns NULL;
*/
const char *regs_query_register_name(unsigned int offset)
{
const struct pt_regs_offset *roff;
for (roff = regoffset_table; roff->name != NULL; roff++)
if (roff->offset == offset)
return roff->name;
return NULL;
}
static const int arg_offs_table[] = {
#ifdef CONFIG_X86_32
[0] = offsetof(struct pt_regs, ax),
[1] = offsetof(struct pt_regs, dx),
[2] = offsetof(struct pt_regs, cx)
#else /* CONFIG_X86_64 */
[0] = offsetof(struct pt_regs, di),
[1] = offsetof(struct pt_regs, si),
[2] = offsetof(struct pt_regs, dx),
[3] = offsetof(struct pt_regs, cx),
[4] = offsetof(struct pt_regs, r8),
[5] = offsetof(struct pt_regs, r9)
#endif
};
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/*
* Determines which flags the user has access to [1 = access, 0 = no access].
*/
#define FLAG_MASK_32 ((unsigned long) \
(X86_EFLAGS_CF | X86_EFLAGS_PF | \
X86_EFLAGS_AF | X86_EFLAGS_ZF | \
X86_EFLAGS_SF | X86_EFLAGS_TF | \
X86_EFLAGS_DF | X86_EFLAGS_OF | \
X86_EFLAGS_RF | X86_EFLAGS_AC))
/*
* Determines whether a value may be installed in a segment register.
*/
static inline bool invalid_selector(u16 value)
{
return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
}
#ifdef CONFIG_X86_32
#define FLAG_MASK FLAG_MASK_32
/*
* X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
* when it traps. The previous stack will be directly underneath the saved
* registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
*
* Now, if the stack is empty, '&regs->sp' is out of range. In this
* case we try to take the previous stack. To always return a non-null
* stack pointer we fall back to regs as stack if no previous stack
* exists.
*
* This is valid only for kernel mode traps.
*/
unsigned long kernel_stack_pointer(struct pt_regs *regs)
{
unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
unsigned long sp = (unsigned long)&regs->sp;
u32 *prev_esp;
if (context == (sp & ~(THREAD_SIZE - 1)))
return sp;
prev_esp = (u32 *)(context);
if (prev_esp)
return (unsigned long)prev_esp;
return (unsigned long)regs;
}
EXPORT_SYMBOL_GPL(kernel_stack_pointer);
static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
{
BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
return &regs->bx + (regno >> 2);
}
static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
{
/*
* Returning the value truncates it to 16 bits.
*/
unsigned int retval;
if (offset != offsetof(struct user_regs_struct, gs))
retval = *pt_regs_access(task_pt_regs(task), offset);
else {
if (task == current)
retval = get_user_gs(task_pt_regs(task));
else
retval = task_user_gs(task);
}
return retval;
}
static int set_segment_reg(struct task_struct *task,
unsigned long offset, u16 value)
{
/*
* The value argument was already truncated to 16 bits.
*/
if (invalid_selector(value))
return -EIO;
/*
* For %cs and %ss we cannot permit a null selector.
* We can permit a bogus selector as long as it has USER_RPL.
* Null selectors are fine for other segment registers, but
* we will never get back to user mode with invalid %cs or %ss
* and will take the trap in iret instead. Much code relies
* on user_mode() to distinguish a user trap frame (which can
* safely use invalid selectors) from a kernel trap frame.
*/
switch (offset) {
case offsetof(struct user_regs_struct, cs):
case offsetof(struct user_regs_struct, ss):
if (unlikely(value == 0))
return -EIO;
default:
*pt_regs_access(task_pt_regs(task), offset) = value;
break;
case offsetof(struct user_regs_struct, gs):
if (task == current)
set_user_gs(task_pt_regs(task), value);
else
task_user_gs(task) = value;
}
return 0;
}
#else /* CONFIG_X86_64 */
#define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT)
static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
{
BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
return &regs->r15 + (offset / sizeof(regs->r15));
}
static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
{
/*
* Returning the value truncates it to 16 bits.
*/
unsigned int seg;
switch (offset) {
case offsetof(struct user_regs_struct, fs):
if (task == current) {
/* Older gas can't assemble movq %?s,%r?? */
asm("movl %%fs,%0" : "=r" (seg));
return seg;
}
return task->thread.fsindex;
case offsetof(struct user_regs_struct, gs):
if (task == current) {
asm("movl %%gs,%0" : "=r" (seg));
return seg;
}
return task->thread.gsindex;
case offsetof(struct user_regs_struct, ds):
if (task == current) {
asm("movl %%ds,%0" : "=r" (seg));
return seg;
}
return task->thread.ds;
case offsetof(struct user_regs_struct, es):
if (task == current) {
asm("movl %%es,%0" : "=r" (seg));
return seg;
}
return task->thread.es;
case offsetof(struct user_regs_struct, cs):
case offsetof(struct user_regs_struct, ss):
break;
}
return *pt_regs_access(task_pt_regs(task), offset);
}
static int set_segment_reg(struct task_struct *task,
unsigned long offset, u16 value)
{
/*
* The value argument was already truncated to 16 bits.
*/
if (invalid_selector(value))
return -EIO;
switch (offset) {
case offsetof(struct user_regs_struct,fs):
/*
* If this is setting fs as for normal 64-bit use but
* setting fs_base has implicitly changed it, leave it.
*/
if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
task->thread.fs != 0) ||
(value == 0 && task->thread.fsindex == FS_TLS_SEL &&
task->thread.fs == 0))
break;
task->thread.fsindex = value;
if (task == current)
loadsegment(fs, task->thread.fsindex);
break;
case offsetof(struct user_regs_struct,gs):
/*
* If this is setting gs as for normal 64-bit use but
* setting gs_base has implicitly changed it, leave it.
*/
if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
task->thread.gs != 0) ||
(value == 0 && task->thread.gsindex == GS_TLS_SEL &&
task->thread.gs == 0))
break;
task->thread.gsindex = value;
if (task == current)
load_gs_index(task->thread.gsindex);
break;
case offsetof(struct user_regs_struct,ds):
task->thread.ds = value;
if (task == current)
loadsegment(ds, task->thread.ds);
break;
case offsetof(struct user_regs_struct,es):
task->thread.es = value;
if (task == current)
loadsegment(es, task->thread.es);
break;
/*
* Can't actually change these in 64-bit mode.
*/
case offsetof(struct user_regs_struct,cs):
if (unlikely(value == 0))
return -EIO;
task_pt_regs(task)->cs = value;
break;
case offsetof(struct user_regs_struct,ss):
if (unlikely(value == 0))
return -EIO;
task_pt_regs(task)->ss = value;
break;
}
return 0;
}
#endif /* CONFIG_X86_32 */
static unsigned long get_flags(struct task_struct *task)
{
unsigned long retval = task_pt_regs(task)->flags;
/*
* If the debugger set TF, hide it from the readout.
*/
if (test_tsk_thread_flag(task, TIF_FORCED_TF))
retval &= ~X86_EFLAGS_TF;
return retval;
}
static int set_flags(struct task_struct *task, unsigned long value)
{
struct pt_regs *regs = task_pt_regs(task);
/*
* If the user value contains TF, mark that
* it was not "us" (the debugger) that set it.
* If not, make sure it stays set if we had.
*/
if (value & X86_EFLAGS_TF)
clear_tsk_thread_flag(task, TIF_FORCED_TF);
else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
value |= X86_EFLAGS_TF;
regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
return 0;
}
static int putreg(struct task_struct *child,
unsigned long offset, unsigned long value)
{
switch (offset) {
case offsetof(struct user_regs_struct, cs):
case offsetof(struct user_regs_struct, ds):
case offsetof(struct user_regs_struct, es):
case offsetof(struct user_regs_struct, fs):
case offsetof(struct user_regs_struct, gs):
case offsetof(struct user_regs_struct, ss):
return set_segment_reg(child, offset, value);
case offsetof(struct user_regs_struct, flags):
return set_flags(child, value);
#ifdef CONFIG_X86_64
case offsetof(struct user_regs_struct,fs_base):
if (value >= TASK_SIZE_OF(child))
return -EIO;
/*
* When changing the segment base, use do_arch_prctl
* to set either thread.fs or thread.fsindex and the
* corresponding GDT slot.
*/
if (child->thread.fs != value)
return do_arch_prctl(child, ARCH_SET_FS, value);
return 0;
case offsetof(struct user_regs_struct,gs_base):
/*
* Exactly the same here as the %fs handling above.
*/
if (value >= TASK_SIZE_OF(child))
return -EIO;
if (child->thread.gs != value)
return do_arch_prctl(child, ARCH_SET_GS, value);
return 0;
#endif
}
*pt_regs_access(task_pt_regs(child), offset) = value;
return 0;
}
static unsigned long getreg(struct task_struct *task, unsigned long offset)
{
switch (offset) {
case offsetof(struct user_regs_struct, cs):
case offsetof(struct user_regs_struct, ds):
case offsetof(struct user_regs_struct, es):
case offsetof(struct user_regs_struct, fs):
case offsetof(struct user_regs_struct, gs):
case offsetof(struct user_regs_struct, ss):
return get_segment_reg(task, offset);
case offsetof(struct user_regs_struct, flags):
return get_flags(task);
#ifdef CONFIG_X86_64
case offsetof(struct user_regs_struct, fs_base): {
/*
* do_arch_prctl may have used a GDT slot instead of
* the MSR. To userland, it appears the same either
* way, except the %fs segment selector might not be 0.
*/
unsigned int seg = task->thread.fsindex;
if (task->thread.fs != 0)
return task->thread.fs;
if (task == current)
asm("movl %%fs,%0" : "=r" (seg));
if (seg != FS_TLS_SEL)
return 0;
return get_desc_base(&task->thread.tls_array[FS_TLS]);
}
case offsetof(struct user_regs_struct, gs_base): {
/*
* Exactly the same here as the %fs handling above.
*/
unsigned int seg = task->thread.gsindex;
if (task->thread.gs != 0)
return task->thread.gs;
if (task == current)
asm("movl %%gs,%0" : "=r" (seg));
if (seg != GS_TLS_SEL)
return 0;
return get_desc_base(&task->thread.tls_array[GS_TLS]);
}
#endif
}
return *pt_regs_access(task_pt_regs(task), offset);
}
static int genregs_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
if (kbuf) {
unsigned long *k = kbuf;
while (count >= sizeof(*k)) {
*k++ = getreg(target, pos);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
unsigned long __user *u = ubuf;
while (count >= sizeof(*u)) {
if (__put_user(getreg(target, pos), u++))
return -EFAULT;
count -= sizeof(*u);
pos += sizeof(*u);
}
}
return 0;
}
static int genregs_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
int ret = 0;
if (kbuf) {
const unsigned long *k = kbuf;
while (count >= sizeof(*k) && !ret) {
ret = putreg(target, pos, *k++);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
const unsigned long __user *u = ubuf;
while (count >= sizeof(*u) && !ret) {
unsigned long word;
ret = __get_user(word, u++);
if (ret)
break;
ret = putreg(target, pos, word);
count -= sizeof(*u);
pos += sizeof(*u);
}
}
return ret;
}
static void ptrace_triggered(struct perf_event *bp,
struct perf_sample_data *data,
struct pt_regs *regs)
{
int i;
struct thread_struct *thread = &(current->thread);
/*
* Store in the virtual DR6 register the fact that the breakpoint
* was hit so the thread's debugger will see it.
*/
for (i = 0; i < HBP_NUM; i++) {
if (thread->ptrace_bps[i] == bp)
break;
}
thread->debugreg6 |= (DR_TRAP0 << i);
}
/*
* Walk through every ptrace breakpoints for this thread and
* build the dr7 value on top of their attributes.
*
*/
static unsigned long ptrace_get_dr7(struct perf_event *bp[])
{
int i;
int dr7 = 0;
struct arch_hw_breakpoint *info;
for (i = 0; i < HBP_NUM; i++) {
if (bp[i] && !bp[i]->attr.disabled) {
info = counter_arch_bp(bp[i]);
dr7 |= encode_dr7(i, info->len, info->type);
}
}
return dr7;
}
static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
int len, int type, bool disabled)
{
int err, bp_len, bp_type;
err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
if (!err) {
attr->bp_len = bp_len;
attr->bp_type = bp_type;
attr->disabled = disabled;
}
return err;
}
static struct perf_event *
ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
unsigned long addr, bool disabled)
{
struct perf_event_attr attr;
int err;
ptrace_breakpoint_init(&attr);
attr.bp_addr = addr;
err = ptrace_fill_bp_fields(&attr, len, type, disabled);
if (err)
return ERR_PTR(err);
return register_user_hw_breakpoint(&attr, ptrace_triggered,
NULL, tsk);
}
static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
int disabled)
{
struct perf_event_attr attr = bp->attr;
int err;
err = ptrace_fill_bp_fields(&attr, len, type, disabled);
if (err)
return err;
return modify_user_hw_breakpoint(bp, &attr);
}
/*
* Handle ptrace writes to debug register 7.
*/
static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
{
struct thread_struct *thread = &tsk->thread;
unsigned long old_dr7;
bool second_pass = false;
int i, rc, ret = 0;
data &= ~DR_CONTROL_RESERVED;
old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
restore:
rc = 0;
for (i = 0; i < HBP_NUM; i++) {
unsigned len, type;
bool disabled = !decode_dr7(data, i, &len, &type);
struct perf_event *bp = thread->ptrace_bps[i];
if (!bp) {
if (disabled)
continue;
bp = ptrace_register_breakpoint(tsk,
len, type, 0, disabled);
if (IS_ERR(bp)) {
rc = PTR_ERR(bp);
break;
}
thread->ptrace_bps[i] = bp;
continue;
}
rc = ptrace_modify_breakpoint(bp, len, type, disabled);
if (rc)
break;
}
/* Restore if the first pass failed, second_pass shouldn't fail. */
if (rc && !WARN_ON(second_pass)) {
ret = rc;
data = old_dr7;
second_pass = true;
goto restore;
}
return ret;
}
/*
* Handle PTRACE_PEEKUSR calls for the debug register area.
*/
static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
{
struct thread_struct *thread = &tsk->thread;
unsigned long val = 0;
if (n < HBP_NUM) {
struct perf_event *bp = thread->ptrace_bps[n];
if (bp)
val = bp->hw.info.address;
} else if (n == 6) {
val = thread->debugreg6;
} else if (n == 7) {
val = thread->ptrace_dr7;
}
return val;
}
static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
unsigned long addr)
{
struct thread_struct *t = &tsk->thread;
struct perf_event *bp = t->ptrace_bps[nr];
int err = 0;
if (!bp) {
/*
* Put stub len and type to create an inactive but correct bp.
*
* CHECKME: the previous code returned -EIO if the addr wasn't
* a valid task virtual addr. The new one will return -EINVAL in
* this case.
* -EINVAL may be what we want for in-kernel breakpoints users,
* but -EIO looks better for ptrace, since we refuse a register
* writing for the user. And anyway this is the previous
* behaviour.
*/
bp = ptrace_register_breakpoint(tsk,
X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
addr, true);
if (IS_ERR(bp))
err = PTR_ERR(bp);
else
t->ptrace_bps[nr] = bp;
} else {
struct perf_event_attr attr = bp->attr;
attr.bp_addr = addr;
err = modify_user_hw_breakpoint(bp, &attr);
}
return err;
}
/*
* Handle PTRACE_POKEUSR calls for the debug register area.
*/
static int ptrace_set_debugreg(struct task_struct *tsk, int n,
unsigned long val)
{
struct thread_struct *thread = &tsk->thread;
/* There are no DR4 or DR5 registers */
int rc = -EIO;
if (n < HBP_NUM) {
rc = ptrace_set_breakpoint_addr(tsk, n, val);
} else if (n == 6) {
thread->debugreg6 = val;
rc = 0;
} else if (n == 7) {
rc = ptrace_write_dr7(tsk, val);
if (!rc)
thread->ptrace_dr7 = val;
}
return rc;
}
/*
* These access the current or another (stopped) task's io permission
* bitmap for debugging or core dump.
*/
static int ioperm_active(struct task_struct *target,
const struct user_regset *regset)
{
return target->thread.io_bitmap_max / regset->size;
}
static int ioperm_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
if (!target->thread.io_bitmap_ptr)
return -ENXIO;
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
target->thread.io_bitmap_ptr,
0, IO_BITMAP_BYTES);
}
/*
* Called by kernel/ptrace.c when detaching..
*
* Make sure the single step bit is not set.
*/
void ptrace_disable(struct task_struct *child)
{
user_disable_single_step(child);
#ifdef TIF_SYSCALL_EMU
clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
#endif
}
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
static const struct user_regset_view user_x86_32_view; /* Initialized below. */
#endif
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
int ret;
unsigned long __user *datap = (unsigned long __user *)data;
switch (request) {
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
unsigned long tmp;
ret = -EIO;
if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
break;
tmp = 0; /* Default return condition */
if (addr < sizeof(struct user_regs_struct))
tmp = getreg(child, addr);
else if (addr >= offsetof(struct user, u_debugreg[0]) &&
addr <= offsetof(struct user, u_debugreg[7])) {
addr -= offsetof(struct user, u_debugreg[0]);
tmp = ptrace_get_debugreg(child, addr / sizeof(data));
}
ret = put_user(tmp, datap);
break;
}
case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
ret = -EIO;
if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
break;
if (addr < sizeof(struct user_regs_struct))
ret = putreg(child, addr, data);
else if (addr >= offsetof(struct user, u_debugreg[0]) &&
addr <= offsetof(struct user, u_debugreg[7])) {
addr -= offsetof(struct user, u_debugreg[0]);
ret = ptrace_set_debugreg(child,
addr / sizeof(data), data);
}
break;
case PTRACE_GETREGS: /* Get all gp regs from the child. */
return copy_regset_to_user(child,
task_user_regset_view(current),
REGSET_GENERAL,
0, sizeof(struct user_regs_struct),
datap);
case PTRACE_SETREGS: /* Set all gp regs in the child. */
return copy_regset_from_user(child,
task_user_regset_view(current),
REGSET_GENERAL,
0, sizeof(struct user_regs_struct),
datap);
case PTRACE_GETFPREGS: /* Get the child FPU state. */
return copy_regset_to_user(child,
task_user_regset_view(current),
REGSET_FP,
0, sizeof(struct user_i387_struct),
datap);
case PTRACE_SETFPREGS: /* Set the child FPU state. */
return copy_regset_from_user(child,
task_user_regset_view(current),
REGSET_FP,
0, sizeof(struct user_i387_struct),
datap);
#ifdef CONFIG_X86_32
case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
return copy_regset_to_user(child, &user_x86_32_view,
REGSET_XFP,
0, sizeof(struct user_fxsr_struct),
datap) ? -EIO : 0;
case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
return copy_regset_from_user(child, &user_x86_32_view,
REGSET_XFP,
0, sizeof(struct user_fxsr_struct),
datap) ? -EIO : 0;
#endif
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
case PTRACE_GET_THREAD_AREA:
if ((int) addr < 0)
return -EIO;
ret = do_get_thread_area(child, addr,
(struct user_desc __user *)data);
break;
case PTRACE_SET_THREAD_AREA:
if ((int) addr < 0)
return -EIO;
ret = do_set_thread_area(child, addr,
(struct user_desc __user *)data, 0);
break;
#endif
#ifdef CONFIG_X86_64
/* normal 64bit interface to access TLS data.
Works just like arch_prctl, except that the arguments
are reversed. */
case PTRACE_ARCH_PRCTL:
ret = do_arch_prctl(child, data, addr);
break;
#endif
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
#ifdef CONFIG_IA32_EMULATION
#include <linux/compat.h>
#include <linux/syscalls.h>
#include <asm/ia32.h>
#include <asm/user32.h>
#define R32(l,q) \
case offsetof(struct user32, regs.l): \
regs->q = value; break
#define SEG32(rs) \
case offsetof(struct user32, regs.rs): \
return set_segment_reg(child, \
offsetof(struct user_regs_struct, rs), \
value); \
break
static int putreg32(struct task_struct *child, unsigned regno, u32 value)
{
struct pt_regs *regs = task_pt_regs(child);
switch (regno) {
SEG32(cs);
SEG32(ds);
SEG32(es);
SEG32(fs);
SEG32(gs);
SEG32(ss);
R32(ebx, bx);
R32(ecx, cx);
R32(edx, dx);
R32(edi, di);
R32(esi, si);
R32(ebp, bp);
R32(eax, ax);
R32(eip, ip);
R32(esp, sp);
case offsetof(struct user32, regs.orig_eax):
/*
* A 32-bit debugger setting orig_eax means to restore
* the state of the task restarting a 32-bit syscall.
* Make sure we interpret the -ERESTART* codes correctly
* in case the task is not actually still sitting at the
* exit from a 32-bit syscall with TS_COMPAT still set.
*/
regs->orig_ax = value;
if (syscall_get_nr(child, regs) >= 0)
task_thread_info(child)->status |= TS_COMPAT;
break;
case offsetof(struct user32, regs.eflags):
return set_flags(child, value);
case offsetof(struct user32, u_debugreg[0]) ...
offsetof(struct user32, u_debugreg[7]):
regno -= offsetof(struct user32, u_debugreg[0]);
return ptrace_set_debugreg(child, regno / 4, value);
default:
if (regno > sizeof(struct user32) || (regno & 3))
return -EIO;
/*
* Other dummy fields in the virtual user structure
* are ignored
*/
break;
}
return 0;
}
#undef R32
#undef SEG32
#define R32(l,q) \
case offsetof(struct user32, regs.l): \
*val = regs->q; break
#define SEG32(rs) \
case offsetof(struct user32, regs.rs): \
*val = get_segment_reg(child, \
offsetof(struct user_regs_struct, rs)); \
break
static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
{
struct pt_regs *regs = task_pt_regs(child);
switch (regno) {
SEG32(ds);
SEG32(es);
SEG32(fs);
SEG32(gs);
R32(cs, cs);
R32(ss, ss);
R32(ebx, bx);
R32(ecx, cx);
R32(edx, dx);
R32(edi, di);
R32(esi, si);
R32(ebp, bp);
R32(eax, ax);
R32(orig_eax, orig_ax);
R32(eip, ip);
R32(esp, sp);
case offsetof(struct user32, regs.eflags):
*val = get_flags(child);
break;
case offsetof(struct user32, u_debugreg[0]) ...
offsetof(struct user32, u_debugreg[7]):
regno -= offsetof(struct user32, u_debugreg[0]);
*val = ptrace_get_debugreg(child, regno / 4);
break;
default:
if (regno > sizeof(struct user32) || (regno & 3))
return -EIO;
/*
* Other dummy fields in the virtual user structure
* are ignored
*/
*val = 0;
break;
}
return 0;
}
#undef R32
#undef SEG32
static int genregs32_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
if (kbuf) {
compat_ulong_t *k = kbuf;
while (count >= sizeof(*k)) {
getreg32(target, pos, k++);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
compat_ulong_t __user *u = ubuf;
while (count >= sizeof(*u)) {
compat_ulong_t word;
getreg32(target, pos, &word);
if (__put_user(word, u++))
return -EFAULT;
count -= sizeof(*u);
pos += sizeof(*u);
}
}
return 0;
}
static int genregs32_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
int ret = 0;
if (kbuf) {
const compat_ulong_t *k = kbuf;
while (count >= sizeof(*k) && !ret) {
ret = putreg32(target, pos, *k++);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
const compat_ulong_t __user *u = ubuf;
while (count >= sizeof(*u) && !ret) {
compat_ulong_t word;
ret = __get_user(word, u++);
if (ret)
break;
ret = putreg32(target, pos, word);
count -= sizeof(*u);
pos += sizeof(*u);
}
}
return ret;
}
#ifdef CONFIG_X86_X32_ABI
static long x32_arch_ptrace(struct task_struct *child,
compat_long_t request, compat_ulong_t caddr,
compat_ulong_t cdata)
{
unsigned long addr = caddr;
unsigned long data = cdata;
void __user *datap = compat_ptr(data);
int ret;
switch (request) {
/* Read 32bits at location addr in the USER area. Only allow
to return the lower 32bits of segment and debug registers. */
case PTRACE_PEEKUSR: {
u32 tmp;
ret = -EIO;
if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
addr < offsetof(struct user_regs_struct, cs))
break;
tmp = 0; /* Default return condition */
if (addr < sizeof(struct user_regs_struct))
tmp = getreg(child, addr);
else if (addr >= offsetof(struct user, u_debugreg[0]) &&
addr <= offsetof(struct user, u_debugreg[7])) {
addr -= offsetof(struct user, u_debugreg[0]);
tmp = ptrace_get_debugreg(child, addr / sizeof(data));
}
ret = put_user(tmp, (__u32 __user *)datap);
break;
}
/* Write the word at location addr in the USER area. Only allow
to update segment and debug registers with the upper 32bits
zero-extended. */
case PTRACE_POKEUSR:
ret = -EIO;
if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
addr < offsetof(struct user_regs_struct, cs))
break;
if (addr < sizeof(struct user_regs_struct))
ret = putreg(child, addr, data);
else if (addr >= offsetof(struct user, u_debugreg[0]) &&
addr <= offsetof(struct user, u_debugreg[7])) {
addr -= offsetof(struct user, u_debugreg[0]);
ret = ptrace_set_debugreg(child,
addr / sizeof(data), data);
}
break;
case PTRACE_GETREGS: /* Get all gp regs from the child. */
return copy_regset_to_user(child,
task_user_regset_view(current),
REGSET_GENERAL,
0, sizeof(struct user_regs_struct),
datap);
case PTRACE_SETREGS: /* Set all gp regs in the child. */
return copy_regset_from_user(child,
task_user_regset_view(current),
REGSET_GENERAL,
0, sizeof(struct user_regs_struct),
datap);
case PTRACE_GETFPREGS: /* Get the child FPU state. */
return copy_regset_to_user(child,
task_user_regset_view(current),
REGSET_FP,
0, sizeof(struct user_i387_struct),
datap);
case PTRACE_SETFPREGS: /* Set the child FPU state. */
return copy_regset_from_user(child,
task_user_regset_view(current),
REGSET_FP,
0, sizeof(struct user_i387_struct),
datap);
default:
return compat_ptrace_request(child, request, addr, data);
}
return ret;
}
#endif
long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
compat_ulong_t caddr, compat_ulong_t cdata)
{
unsigned long addr = caddr;
unsigned long data = cdata;
void __user *datap = compat_ptr(data);
int ret;
__u32 val;
#ifdef CONFIG_X86_X32_ABI
if (!is_ia32_task())
return x32_arch_ptrace(child, request, caddr, cdata);
#endif
switch (request) {
case PTRACE_PEEKUSR:
ret = getreg32(child, addr, &val);
if (ret == 0)
ret = put_user(val, (__u32 __user *)datap);
break;
case PTRACE_POKEUSR:
ret = putreg32(child, addr, data);
break;
case PTRACE_GETREGS: /* Get all gp regs from the child. */
return copy_regset_to_user(child, &user_x86_32_view,
REGSET_GENERAL,
0, sizeof(struct user_regs_struct32),
datap);
case PTRACE_SETREGS: /* Set all gp regs in the child. */
return copy_regset_from_user(child, &user_x86_32_view,
REGSET_GENERAL, 0,
sizeof(struct user_regs_struct32),
datap);
case PTRACE_GETFPREGS: /* Get the child FPU state. */
return copy_regset_to_user(child, &user_x86_32_view,
REGSET_FP, 0,
sizeof(struct user_i387_ia32_struct),
datap);
case PTRACE_SETFPREGS: /* Set the child FPU state. */
return copy_regset_from_user(
child, &user_x86_32_view, REGSET_FP,
0, sizeof(struct user_i387_ia32_struct), datap);
case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
return copy_regset_to_user(child, &user_x86_32_view,
REGSET_XFP, 0,
sizeof(struct user32_fxsr_struct),
datap);
case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
return copy_regset_from_user(child, &user_x86_32_view,
REGSET_XFP, 0,
sizeof(struct user32_fxsr_struct),
datap);
case PTRACE_GET_THREAD_AREA:
case PTRACE_SET_THREAD_AREA:
return arch_ptrace(child, request, addr, data);
default:
return compat_ptrace_request(child, request, addr, data);
}
return ret;
}
#endif /* CONFIG_IA32_EMULATION */
#ifdef CONFIG_X86_64
static struct user_regset x86_64_regsets[] __read_mostly = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
.n = sizeof(struct user_regs_struct) / sizeof(long),
.size = sizeof(long), .align = sizeof(long),
.get = genregs_get, .set = genregs_set
},
[REGSET_FP] = {
.core_note_type = NT_PRFPREG,
.n = sizeof(struct user_i387_struct) / sizeof(long),
.size = sizeof(long), .align = sizeof(long),
.active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
},
[REGSET_XSTATE] = {
.core_note_type = NT_X86_XSTATE,
.size = sizeof(u64), .align = sizeof(u64),
.active = xstateregs_active, .get = xstateregs_get,
.set = xstateregs_set
},
[REGSET_IOPERM64] = {
.core_note_type = NT_386_IOPERM,
.n = IO_BITMAP_LONGS,
.size = sizeof(long), .align = sizeof(long),
.active = ioperm_active, .get = ioperm_get
},
};
static const struct user_regset_view user_x86_64_view = {
.name = "x86_64", .e_machine = EM_X86_64,
.regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
};
#else /* CONFIG_X86_32 */
#define user_regs_struct32 user_regs_struct
#define genregs32_get genregs_get
#define genregs32_set genregs_set
#endif /* CONFIG_X86_64 */
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
static struct user_regset x86_32_regsets[] __read_mostly = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
.n = sizeof(struct user_regs_struct32) / sizeof(u32),
.size = sizeof(u32), .align = sizeof(u32),
.get = genregs32_get, .set = genregs32_set
},
[REGSET_FP] = {
.core_note_type = NT_PRFPREG,
.n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
.size = sizeof(u32), .align = sizeof(u32),
.active = fpregs_active, .get = fpregs_get, .set = fpregs_set
},
[REGSET_XFP] = {
.core_note_type = NT_PRXFPREG,
.n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
.size = sizeof(u32), .align = sizeof(u32),
.active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
},
[REGSET_XSTATE] = {
.core_note_type = NT_X86_XSTATE,
.size = sizeof(u64), .align = sizeof(u64),
.active = xstateregs_active, .get = xstateregs_get,
.set = xstateregs_set
},
[REGSET_TLS] = {
.core_note_type = NT_386_TLS,
.n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
.size = sizeof(struct user_desc),
.align = sizeof(struct user_desc),
.active = regset_tls_active,
.get = regset_tls_get, .set = regset_tls_set
},
[REGSET_IOPERM32] = {
.core_note_type = NT_386_IOPERM,
.n = IO_BITMAP_BYTES / sizeof(u32),
.size = sizeof(u32), .align = sizeof(u32),
.active = ioperm_active, .get = ioperm_get
},
};
static const struct user_regset_view user_x86_32_view = {
.name = "i386", .e_machine = EM_386,
.regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
};
#endif
/*
* This represents bytes 464..511 in the memory layout exported through
* the REGSET_XSTATE interface.
*/
u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
{
#ifdef CONFIG_X86_64
x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
#endif
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
#endif
xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
}
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
#ifdef CONFIG_IA32_EMULATION
if (test_tsk_thread_flag(task, TIF_IA32))
#endif
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
return &user_x86_32_view;
#endif
#ifdef CONFIG_X86_64
return &user_x86_64_view;
#endif
}
static void fill_sigtrap_info(struct task_struct *tsk,
struct pt_regs *regs,
int error_code, int si_code,
struct siginfo *info)
{
tsk->thread.trap_nr = X86_TRAP_DB;
tsk->thread.error_code = error_code;
memset(info, 0, sizeof(*info));
info->si_signo = SIGTRAP;
info->si_code = si_code;
info->si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
}
void user_single_step_siginfo(struct task_struct *tsk,
struct pt_regs *regs,
struct siginfo *info)
{
fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
}
void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
int error_code, int si_code)
{
struct siginfo info;
fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
/* Send us the fake SIGTRAP */
force_sig_info(SIGTRAP, &info, tsk);
}
static void do_audit_syscall_entry(struct pt_regs *regs, u32 arch)
{
#ifdef CONFIG_X86_64
if (arch == AUDIT_ARCH_X86_64) {
audit_syscall_entry(regs->orig_ax, regs->di,
regs->si, regs->dx, regs->r10);
} else
#endif
{
audit_syscall_entry(regs->orig_ax, regs->bx,
regs->cx, regs->dx, regs->si);
}
}
/*
* We can return 0 to resume the syscall or anything else to go to phase
* 2. If we resume the syscall, we need to put something appropriate in
* regs->orig_ax.
*
* NB: We don't have full pt_regs here, but regs->orig_ax and regs->ax
* are fully functional.
*
* For phase 2's benefit, our return value is:
* 0: resume the syscall
* 1: go to phase 2; no seccomp phase 2 needed
* anything else: go to phase 2; pass return value to seccomp
*/
unsigned long syscall_trace_enter_phase1(struct pt_regs *regs, u32 arch)
{
unsigned long ret = 0;
u32 work;
BUG_ON(regs != task_pt_regs(current));
work = ACCESS_ONCE(current_thread_info()->flags) &
_TIF_WORK_SYSCALL_ENTRY;
/*
* If TIF_NOHZ is set, we are required to call user_exit() before
* doing anything that could touch RCU.
*/
if (work & _TIF_NOHZ) {
user_exit();
work &= ~_TIF_NOHZ;
}
#ifdef CONFIG_SECCOMP
/*
* Do seccomp first -- it should minimize exposure of other
* code, and keeping seccomp fast is probably more valuable
* than the rest of this.
*/
if (work & _TIF_SECCOMP) {
struct seccomp_data sd;
sd.arch = arch;
sd.nr = regs->orig_ax;
sd.instruction_pointer = regs->ip;
#ifdef CONFIG_X86_64
if (arch == AUDIT_ARCH_X86_64) {
sd.args[0] = regs->di;
sd.args[1] = regs->si;
sd.args[2] = regs->dx;
sd.args[3] = regs->r10;
sd.args[4] = regs->r8;
sd.args[5] = regs->r9;
} else
#endif
{
sd.args[0] = regs->bx;
sd.args[1] = regs->cx;
sd.args[2] = regs->dx;
sd.args[3] = regs->si;
sd.args[4] = regs->di;
sd.args[5] = regs->bp;
}
BUILD_BUG_ON(SECCOMP_PHASE1_OK != 0);
BUILD_BUG_ON(SECCOMP_PHASE1_SKIP != 1);
ret = seccomp_phase1(&sd);
if (ret == SECCOMP_PHASE1_SKIP) {
regs->orig_ax = -1;
ret = 0;
} else if (ret != SECCOMP_PHASE1_OK) {
return ret; /* Go directly to phase 2 */
}
work &= ~_TIF_SECCOMP;
}
#endif
/* Do our best to finish without phase 2. */
if (work == 0)
return ret; /* seccomp and/or nohz only (ret == 0 here) */
#ifdef CONFIG_AUDITSYSCALL
if (work == _TIF_SYSCALL_AUDIT) {
/*
* If there is no more work to be done except auditing,
* then audit in phase 1. Phase 2 always audits, so, if
* we audit here, then we can't go on to phase 2.
*/
do_audit_syscall_entry(regs, arch);
return 0;
}
#endif
return 1; /* Something is enabled that we can't handle in phase 1 */
}
/* Returns the syscall nr to run (which should match regs->orig_ax). */
long syscall_trace_enter_phase2(struct pt_regs *regs, u32 arch,
unsigned long phase1_result)
{
long ret = 0;
u32 work = ACCESS_ONCE(current_thread_info()->flags) &
_TIF_WORK_SYSCALL_ENTRY;
BUG_ON(regs != task_pt_regs(current));
/*
* If we stepped into a sysenter/syscall insn, it trapped in
* kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
* If user-mode had set TF itself, then it's still clear from
* do_debug() and we need to set it again to restore the user
* state. If we entered on the slow path, TF was already set.
*/
if (work & _TIF_SINGLESTEP)
regs->flags |= X86_EFLAGS_TF;
#ifdef CONFIG_SECCOMP
/*
* Call seccomp_phase2 before running the other hooks so that
* they can see any changes made by a seccomp tracer.
*/
if (phase1_result > 1 && seccomp_phase2(phase1_result)) {
/* seccomp failures shouldn't expose any additional code. */
return -1;
}
#endif
if (unlikely(work & _TIF_SYSCALL_EMU))
ret = -1L;
if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
tracehook_report_syscall_entry(regs))
ret = -1L;
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
trace_sys_enter(regs, regs->orig_ax);
do_audit_syscall_entry(regs, arch);
return ret ?: regs->orig_ax;
}
long syscall_trace_enter(struct pt_regs *regs)
{
u32 arch = is_ia32_task() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
unsigned long phase1_result = syscall_trace_enter_phase1(regs, arch);
if (phase1_result == 0)
return regs->orig_ax;
else
return syscall_trace_enter_phase2(regs, arch, phase1_result);
}
void syscall_trace_leave(struct pt_regs *regs)
{
bool step;
/*
* We may come here right after calling schedule_user()
* or do_notify_resume(), in which case we can be in RCU
* user mode.
*/
user_exit();
audit_syscall_exit(regs);
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
trace_sys_exit(regs, regs->ax);
/*
* If TIF_SYSCALL_EMU is set, we only get here because of
* TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
* We already reported this syscall instruction in
* syscall_trace_enter().
*/
step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
!test_thread_flag(TIF_SYSCALL_EMU);
if (step || test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, step);
user_enter();
}
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