linux-stable/arch/x86/kernel/ptrace.c
Chang S. Bae 87ab4689ca x86/fsgsbase/64: Fix the base write helper functions
Andy spotted a regression in the fs/gs base helpers after the patch series
was committed. The helper functions which write fs/gs base are not just
writing the base, they are also changing the index. That's wrong and needs
to be separated because writing the base has not to modify the index.

While the regression is not causing any harm right now because the only
caller depends on that behaviour, it's a guarantee for subtle breakage down
the road.

Make the index explicitly changed from the caller, instead of including
the code in the helpers.

Subsequently, the task write helpers do not handle for the current task
anymore. The range check for a base value is also factored out, to minimize
code redundancy from the caller.

Fixes: b1378a561f ("x86/fsgsbase/64: Introduce FS/GS base helper functions")
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20181126195524.32179-1-chang.seok.bae@intel.com
2018-12-18 14:26:09 +01:00

1377 lines
34 KiB
C

/* 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/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/ptrace.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 <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/fpu/internal.h>
#include <asm/fpu/signal.h>
#include <asm/fpu/regset.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 <asm/syscall.h>
#include <asm/fsgsbase.h>
#include "tls.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;
}
/*
* 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):
task->thread.fsindex = value;
if (task == current)
loadsegment(fs, task->thread.fsindex);
break;
case offsetof(struct user_regs_struct,gs):
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_MAX)
return -EIO;
/*
* When changing the FS base, use do_arch_prctl_64()
* to set the index to zero and to set the base
* as requested.
*/
if (child->thread.fsbase != value)
return do_arch_prctl_64(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_MAX)
return -EIO;
if (child->thread.gsbase != value)
return do_arch_prctl_64(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):
return x86_fsbase_read_task(task);
case offsetof(struct user_regs_struct, gs_base):
return x86_gsbase_read_task(task);
#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_64(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):
/*
* Warning: bizarre corner case fixup here. A 32-bit
* debugger setting orig_eax to -1 wants to disable
* syscall restart. Make sure that the syscall
* restart code sign-extends orig_ax. Also make sure
* we interpret the -ERESTART* codes correctly if
* loaded into regs->ax 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)
child->thread_info.status |= TS_I386_REGS_POKED;
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;
}
static long ia32_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;
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_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
#ifdef CONFIG_COMPAT
long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
compat_ulong_t caddr, compat_ulong_t cdata)
{
#ifdef CONFIG_X86_X32_ABI
if (!in_ia32_syscall())
return x32_arch_ptrace(child, request, caddr, cdata);
#endif
#ifdef CONFIG_IA32_EMULATION
return ia32_arch_ptrace(child, request, caddr, cdata);
#else
return 0;
#endif
}
#endif /* CONFIG_COMPAT */
#ifdef CONFIG_X86_64
static struct user_regset x86_64_regsets[] __ro_after_init = {
[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 = regset_xregset_fpregs_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[] __ro_after_init = {
[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 = regset_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 = regset_xregset_fpregs_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 __init 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 (!user_64bit_mode(task_pt_regs(task)))
#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
}
void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
int error_code, int si_code)
{
tsk->thread.trap_nr = X86_TRAP_DB;
tsk->thread.error_code = error_code;
/* Send us the fake SIGTRAP */
force_sig_fault(SIGTRAP, si_code,
user_mode(regs) ? (void __user *)regs->ip : NULL, tsk);
}
void user_single_step_report(struct pt_regs *regs)
{
send_sigtrap(current, regs, 0, TRAP_BRKPT);
}