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linux/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
*
* BTS tracing
* Markus Metzger <markus.t.metzger@intel.com>, Dec 2007
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.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 <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/i387.h>
#include <asm/debugreg.h>
#include <asm/ldt.h>
#include <asm/desc.h>
#include <asm/prctl.h>
#include <asm/proto.h>
#include <asm/ds.h>
#include "tls.h"
enum x86_regset {
REGSET_GENERAL,
REGSET_FP,
REGSET_XFP,
REGSET_IOPERM64 = REGSET_XFP,
REGSET_TLS,
REGSET_IOPERM32,
};
/*
* 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
static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
{
BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
regno >>= 2;
if (regno > FS)
--regno;
return &regs->bx + regno;
}
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 {
retval = task->thread.gs;
if (task == current)
savesegment(gs, retval);
}
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):
task->thread.gs = value;
if (task == current)
/*
* The user-mode %gs is not affected by
* kernel entry, so we must update the CPU.
*/
loadsegment(gs, value);
}
return 0;
}
static unsigned long debugreg_addr_limit(struct task_struct *task)
{
return TASK_SIZE - 3;
}
#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;
#ifdef CONFIG_IA32_EMULATION
if (test_tsk_thread_flag(task, TIF_IA32))
task_pt_regs(task)->cs = value;
#endif
break;
case offsetof(struct user_regs_struct,ss):
if (unlikely(value == 0))
return -EIO;
#ifdef CONFIG_IA32_EMULATION
if (test_tsk_thread_flag(task, TIF_IA32))
task_pt_regs(task)->ss = value;
#endif
break;
}
return 0;
}
static unsigned long debugreg_addr_limit(struct task_struct *task)
{
#ifdef CONFIG_IA32_EMULATION
if (test_tsk_thread_flag(task, TIF_IA32))
return IA32_PAGE_OFFSET - 3;
#endif
return TASK_SIZE64 - 7;
}
#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
/*
* Orig_ax is really just a flag with small positive and
* negative values, so make sure to always sign-extend it
* from 32 bits so that it works correctly regardless of
* whether we come from a 32-bit environment or not.
*/
case offsetof(struct user_regs_struct, orig_ax):
value = (long) (s32) value;
break;
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 > 0) {
*k++ = getreg(target, pos);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
unsigned long __user *u = ubuf;
while (count > 0) {
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 > 0 && !ret) {
ret = putreg(target, pos, *k++);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
const unsigned long __user *u = ubuf;
while (count > 0 && !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;
}
/*
* This function is trivial and will be inlined by the compiler.
* Having it separates the implementation details of debug
* registers from the interface details of ptrace.
*/
static unsigned long ptrace_get_debugreg(struct task_struct *child, int 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 >= debugreg_addr_limit(child)))
return -EIO;
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:
if ((data & ~0xffffffffUL) != 0)
return -EIO;
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
* R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
* 2 and 3 are LENi. Given a list of invalid values,
* we do mask |= 1 << invalid_value, so that
* (mask >> check) & 1 is a correct test for invalid
* values.
*
* R/Wi contains the type of the breakpoint /
* watchpoint, LENi contains the length of the watched
* data in the watchpoint case.
*
* The invalid values are:
* - LENi == 0x10 (undefined), so mask |= 0x0f00. [32-bit]
* - R/Wi == 0x10 (break on I/O reads or writes), so
* mask |= 0x4444.
* - R/Wi == 0x00 && LENi != 0x00, so we have mask |=
* 0x1110.
*
* Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.
*
* See the Intel Manual "System Programming Guide",
* 15.2.4
*
* Note that LENi == 0x10 is defined on x86_64 in long
* mode (i.e. even for 32-bit userspace software, but
* 64-bit kernel), so the x86_64 mask value is 0x5454.
* See the AMD manual no. 24593 (AMD64 System Programming)
*/
#ifdef CONFIG_X86_32
#define DR7_MASK 0x5f54
#else
#define DR7_MASK 0x5554
#endif
data &= ~DR_CONTROL_RESERVED;
for (i = 0; i < 4; i++)
if ((DR7_MASK >> ((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;
}
return 0;
}
/*
* 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);
}
#ifdef CONFIG_X86_PTRACE_BTS
/*
* The configuration for a particular BTS hardware implementation.
*/
struct bts_configuration {
/* the size of a BTS record in bytes; at most BTS_MAX_RECORD_SIZE */
unsigned char sizeof_bts;
/* the size of a field in the BTS record in bytes */
unsigned char sizeof_field;
/* a bitmask to enable/disable BTS in DEBUGCTL MSR */
unsigned long debugctl_mask;
};
static struct bts_configuration bts_cfg;
#define BTS_MAX_RECORD_SIZE (8 * 3)
/*
* Branch Trace Store (BTS) uses the following format. Different
* architectures vary in the size of those fields.
* - source linear address
* - destination linear address
* - flags
*
* Later architectures use 64bit pointers throughout, whereas earlier
* architectures use 32bit pointers in 32bit mode.
*
* We compute the base address for the first 8 fields based on:
* - the field size stored in the DS configuration
* - the relative field position
*
* In order to store additional information in the BTS buffer, we use
* a special source address to indicate that the record requires
* special interpretation.
*
* Netburst indicated via a bit in the flags field whether the branch
* was predicted; this is ignored.
*/
enum bts_field {
bts_from = 0,
bts_to,
bts_flags,
bts_escape = (unsigned long)-1,
bts_qual = bts_to,
bts_jiffies = bts_flags
};
static inline unsigned long bts_get(const char *base, enum bts_field field)
{
base += (bts_cfg.sizeof_field * field);
return *(unsigned long *)base;
}
static inline void bts_set(char *base, enum bts_field field, unsigned long val)
{
base += (bts_cfg.sizeof_field * field);;
(*(unsigned long *)base) = val;
}
/*
* Translate a BTS record from the raw format into the bts_struct format
*
* out (out): bts_struct interpretation
* raw: raw BTS record
*/
static void ptrace_bts_translate_record(struct bts_struct *out, const void *raw)
{
memset(out, 0, sizeof(*out));
if (bts_get(raw, bts_from) == bts_escape) {
out->qualifier = bts_get(raw, bts_qual);
out->variant.jiffies = bts_get(raw, bts_jiffies);
} else {
out->qualifier = BTS_BRANCH;
out->variant.lbr.from_ip = bts_get(raw, bts_from);
out->variant.lbr.to_ip = bts_get(raw, bts_to);
}
}
static int ptrace_bts_read_record(struct task_struct *child, size_t index,
struct bts_struct __user *out)
{
struct bts_struct ret;
const void *bts_record;
size_t bts_index, bts_end;
int error;
error = ds_get_bts_end(child, &bts_end);
if (error < 0)
return error;
if (bts_end <= index)
return -EINVAL;
error = ds_get_bts_index(child, &bts_index);
if (error < 0)
return error;
/* translate the ptrace bts index into the ds bts index */
bts_index += bts_end - (index + 1);
if (bts_end <= bts_index)
bts_index -= bts_end;
error = ds_access_bts(child, bts_index, &bts_record);
if (error < 0)
return error;
ptrace_bts_translate_record(&ret, bts_record);
if (copy_to_user(out, &ret, sizeof(ret)))
return -EFAULT;
return sizeof(ret);
}
static int ptrace_bts_drain(struct task_struct *child,
long size,
struct bts_struct __user *out)
{
struct bts_struct ret;
const unsigned char *raw;
size_t end, i;
int error;
error = ds_get_bts_index(child, &end);
if (error < 0)
return error;
if (size < (end * sizeof(struct bts_struct)))
return -EIO;
error = ds_access_bts(child, 0, (const void **)&raw);
if (error < 0)
return error;
for (i = 0; i < end; i++, out++, raw += bts_cfg.sizeof_bts) {
ptrace_bts_translate_record(&ret, raw);
if (copy_to_user(out, &ret, sizeof(ret)))
return -EFAULT;
}
error = ds_clear_bts(child);
if (error < 0)
return error;
return end;
}
static void ptrace_bts_ovfl(struct task_struct *child)
{
send_sig(child->thread.bts_ovfl_signal, child, 0);
}
static int ptrace_bts_config(struct task_struct *child,
long cfg_size,
const struct ptrace_bts_config __user *ucfg)
{
struct ptrace_bts_config cfg;
int error = 0;
error = -EOPNOTSUPP;
if (!bts_cfg.sizeof_bts)
goto errout;
error = -EIO;
if (cfg_size < sizeof(cfg))
goto errout;
error = -EFAULT;
if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
goto errout;
error = -EINVAL;
if ((cfg.flags & PTRACE_BTS_O_SIGNAL) &&
!(cfg.flags & PTRACE_BTS_O_ALLOC))
goto errout;
if (cfg.flags & PTRACE_BTS_O_ALLOC) {
ds_ovfl_callback_t ovfl = NULL;
unsigned int sig = 0;
/* we ignore the error in case we were not tracing child */
(void)ds_release_bts(child);
if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
if (!cfg.signal)
goto errout;
sig = cfg.signal;
ovfl = ptrace_bts_ovfl;
}
error = ds_request_bts(child, /* base = */ NULL, cfg.size, ovfl);
if (error < 0)
goto errout;
child->thread.bts_ovfl_signal = sig;
}
error = -EINVAL;
if (!child->thread.ds_ctx && cfg.flags)
goto errout;
if (cfg.flags & PTRACE_BTS_O_TRACE)
child->thread.debugctlmsr |= bts_cfg.debugctl_mask;
else
child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
if (cfg.flags & PTRACE_BTS_O_SCHED)
set_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
else
clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
error = sizeof(cfg);
out:
if (child->thread.debugctlmsr)
set_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
else
clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
return error;
errout:
child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
goto out;
}
static int ptrace_bts_status(struct task_struct *child,
long cfg_size,
struct ptrace_bts_config __user *ucfg)
{
struct ptrace_bts_config cfg;
size_t end;
const void *base, *max;
int error;
if (cfg_size < sizeof(cfg))
return -EIO;
error = ds_get_bts_end(child, &end);
if (error < 0)
return error;
error = ds_access_bts(child, /* index = */ 0, &base);
if (error < 0)
return error;
error = ds_access_bts(child, /* index = */ end, &max);
if (error < 0)
return error;
memset(&cfg, 0, sizeof(cfg));
cfg.size = (max - base);
cfg.signal = child->thread.bts_ovfl_signal;
cfg.bts_size = sizeof(struct bts_struct);
if (cfg.signal)
cfg.flags |= PTRACE_BTS_O_SIGNAL;
if (test_tsk_thread_flag(child, TIF_DEBUGCTLMSR) &&
child->thread.debugctlmsr & bts_cfg.debugctl_mask)
cfg.flags |= PTRACE_BTS_O_TRACE;
if (test_tsk_thread_flag(child, TIF_BTS_TRACE_TS))
cfg.flags |= PTRACE_BTS_O_SCHED;
if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
return -EFAULT;
return sizeof(cfg);
}
static int ptrace_bts_write_record(struct task_struct *child,
const struct bts_struct *in)
{
unsigned char bts_record[BTS_MAX_RECORD_SIZE];
BUG_ON(BTS_MAX_RECORD_SIZE < bts_cfg.sizeof_bts);
memset(bts_record, 0, bts_cfg.sizeof_bts);
switch (in->qualifier) {
case BTS_INVALID:
break;
case BTS_BRANCH:
bts_set(bts_record, bts_from, in->variant.lbr.from_ip);
bts_set(bts_record, bts_to, in->variant.lbr.to_ip);
break;
case BTS_TASK_ARRIVES:
case BTS_TASK_DEPARTS:
bts_set(bts_record, bts_from, bts_escape);
bts_set(bts_record, bts_qual, in->qualifier);
bts_set(bts_record, bts_jiffies, in->variant.jiffies);
break;
default:
return -EINVAL;
}
/* The writing task will be the switched-to task on a context
* switch. It needs to write into the switched-from task's BTS
* buffer. */
return ds_unchecked_write_bts(child, bts_record, bts_cfg.sizeof_bts);
}
void ptrace_bts_take_timestamp(struct task_struct *tsk,
enum bts_qualifier qualifier)
{
struct bts_struct rec = {
.qualifier = qualifier,
.variant.jiffies = jiffies_64
};
ptrace_bts_write_record(tsk, &rec);
}
static const struct bts_configuration bts_cfg_netburst = {
.sizeof_bts = sizeof(long) * 3,
.sizeof_field = sizeof(long),
.debugctl_mask = (1<<2)|(1<<3)|(1<<5)
};
static const struct bts_configuration bts_cfg_pentium_m = {
.sizeof_bts = sizeof(long) * 3,
.sizeof_field = sizeof(long),
.debugctl_mask = (1<<6)|(1<<7)
};
static const struct bts_configuration bts_cfg_core2 = {
.sizeof_bts = 8 * 3,
.sizeof_field = 8,
.debugctl_mask = (1<<6)|(1<<7)|(1<<9)
};
static inline void bts_configure(const struct bts_configuration *cfg)
{
bts_cfg = *cfg;
}
void __cpuinit ptrace_bts_init_intel(struct cpuinfo_x86 *c)
{
switch (c->x86) {
case 0x6:
switch (c->x86_model) {
case 0xD:
case 0xE: /* Pentium M */
bts_configure(&bts_cfg_pentium_m);
break;
case 0xF: /* Core2 */
case 0x1C: /* Atom */
bts_configure(&bts_cfg_core2);
break;
default:
/* sorry, don't know about them */
break;
}
break;
case 0xF:
switch (c->x86_model) {
case 0x0:
case 0x1:
case 0x2: /* Netburst */
bts_configure(&bts_cfg_netburst);
break;
default:
/* sorry, don't know about them */
break;
}
break;
default:
/* sorry, don't know about them */
break;
}
}
#endif /* CONFIG_X86_PTRACE_BTS */
/*
* 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
#ifdef CONFIG_X86_PTRACE_BTS
(void)ds_release_bts(child);
child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
if (!child->thread.debugctlmsr)
clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
#endif /* CONFIG_X86_PTRACE_BTS */
}
#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, long addr, 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 < 0 ||
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 < 0 ||
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 (addr < 0)
return -EIO;
ret = do_get_thread_area(child, addr,
(struct user_desc __user *) data);
break;
case PTRACE_SET_THREAD_AREA:
if (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
/*
* These bits need more cooking - not enabled yet:
*/
#ifdef CONFIG_X86_PTRACE_BTS
case PTRACE_BTS_CONFIG:
ret = ptrace_bts_config
(child, data, (struct ptrace_bts_config __user *)addr);
break;
case PTRACE_BTS_STATUS:
ret = ptrace_bts_status
(child, data, (struct ptrace_bts_config __user *)addr);
break;
case PTRACE_BTS_SIZE:
ret = ds_get_bts_index(child, /* pos = */ NULL);
break;
case PTRACE_BTS_GET:
ret = ptrace_bts_read_record
(child, data, (struct bts_struct __user *) addr);
break;
case PTRACE_BTS_CLEAR:
ret = ds_clear_bts(child);
break;
case PTRACE_BTS_DRAIN:
ret = ptrace_bts_drain
(child, data, (struct bts_struct __user *) addr);
break;
#endif /* CONFIG_X86_PTRACE_BTS */
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):
/*
* Sign-extend the value so that orig_eax = -1
* causes (long)orig_ax < 0 tests to fire correctly.
*/
regs->orig_ax = (long) (s32) value;
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 > 0) {
getreg32(target, pos, k++);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
compat_ulong_t __user *u = ubuf;
while (count > 0) {
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 > 0 && !ret) {
ret = putreg32(target, pos, *k++);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
const compat_ulong_t __user *u = ubuf;
while (count > 0 && !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;
}
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;
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 const struct user_regset x86_64_regsets[] = {
[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_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
#define user_i387_ia32_struct user_i387_struct
#define user32_fxsr_struct user_fxsr_struct
#endif /* CONFIG_X86_64 */
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
static const struct user_regset x86_32_regsets[] = {
[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_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
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
}
void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
int error_code, int si_code)
{
struct siginfo info;
tsk->thread.trap_no = 1;
tsk->thread.error_code = error_code;
memset(&info, 0, sizeof(info));
info.si_signo = SIGTRAP;
info.si_code = si_code;
/* User-mode ip? */
info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;
/* Send us the fake SIGTRAP */
force_sig_info(SIGTRAP, &info, tsk);
}
#ifdef CONFIG_X86_32
# define IS_IA32 1
#elif defined CONFIG_IA32_EMULATION
# define IS_IA32 test_thread_flag(TIF_IA32)
#else
# define IS_IA32 0
#endif
/*
* We must return the syscall number to actually look up in the table.
* This can be -1L to skip running any syscall at all.
*/
asmregparm long syscall_trace_enter(struct pt_regs *regs)
{
long ret = 0;
/*
* 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 (test_thread_flag(TIF_SINGLESTEP))
regs->flags |= X86_EFLAGS_TF;
/* do the secure computing check first */
secure_computing(regs->orig_ax);
if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
ret = -1L;
if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
tracehook_report_syscall_entry(regs))
ret = -1L;
if (unlikely(current->audit_context)) {
if (IS_IA32)
audit_syscall_entry(AUDIT_ARCH_I386,
regs->orig_ax,
regs->bx, regs->cx,
regs->dx, regs->si);
#ifdef CONFIG_X86_64
else
audit_syscall_entry(AUDIT_ARCH_X86_64,
regs->orig_ax,
regs->di, regs->si,
regs->dx, regs->r10);
#endif
}
return ret ?: regs->orig_ax;
}
asmregparm void syscall_trace_leave(struct pt_regs *regs)
{
if (unlikely(current->audit_context))
audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, 0);
/*
* 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(), so don't do any more now.
*/
if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
return;
/*
* If we are single-stepping, synthesize a trap to follow the
* system call instruction.
*/
if (test_thread_flag(TIF_SINGLESTEP) &&
tracehook_consider_fatal_signal(current, SIGTRAP, SIG_DFL))
send_sigtrap(current, regs, 0, TRAP_BRKPT);
}
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