// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/kernel/ptrace.c
*
* By Ross Biro 1/23/92
* edited by Linus Torvalds
* ARM modifications Copyright (C) 2000 Russell King
*/
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/elf.h>
#include <linux/smp.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/security.h>
#include <linux/init.h>
#include <linux/signal.h>
#include <linux/uaccess.h>
#include <linux/perf_event.h>
#include <linux/hw_breakpoint.h>
#include <linux/regset.h>
#include <linux/audit.h>
#include <linux/unistd.h>
#include <asm/syscall.h>
#include <asm/traps.h>
#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>
#define REG_PC 15
#define REG_PSR 16
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
#if 0
/*
* Breakpoint SWI instruction: SWI &9F0001
*/
#define BREAKINST_ARM 0xef9f0001
#define BREAKINST_THUMB 0xdf00 /* fill this in later */
#else
/*
* New breakpoints - use an undefined instruction. The ARM architecture
* reference manual guarantees that the following instruction space
* will produce an undefined instruction exception on all CPUs:
*
* ARM: xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx
* Thumb: 1101 1110 xxxx xxxx
*/
#define BREAKINST_ARM 0xe7f001f0
#define BREAKINST_THUMB 0xde01
#endif
struct pt_regs_offset {
const char *name;
int offset;
};
#define REG_OFFSET_NAME(r) \
{.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
#define REG_OFFSET_END {.name = NULL, .offset = 0}
static const struct pt_regs_offset regoffset_table[] = {
REG_OFFSET_NAME(r0),
REG_OFFSET_NAME(r1),
REG_OFFSET_NAME(r2),
REG_OFFSET_NAME(r3),
REG_OFFSET_NAME(r4),
REG_OFFSET_NAME(r5),
REG_OFFSET_NAME(r6),
REG_OFFSET_NAME(r7),
REG_OFFSET_NAME(r8),
REG_OFFSET_NAME(r9),
REG_OFFSET_NAME(r10),
REG_OFFSET_NAME(fp),
REG_OFFSET_NAME(ip),
REG_OFFSET_NAME(sp),
REG_OFFSET_NAME(lr),
REG_OFFSET_NAME(pc),
REG_OFFSET_NAME(cpsr),
REG_OFFSET_NAME(ORIG_r0),
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;
}
/**
* regs_within_kernel_stack() - check the address in the stack
* @regs: pt_regs which contains kernel stack pointer.
* @addr: address which is checked.
*
* regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
* If @addr is within the kernel stack, it returns true. If not, returns false.
*/
bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
{
return ((addr & ~(THREAD_SIZE - 1)) ==
(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
}
/**
* regs_get_kernel_stack_nth() - get Nth entry of the stack
* @regs: pt_regs which contains kernel stack pointer.
* @n: stack entry number.
*
* regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
* is specified by @regs. If the @n th entry is NOT in the kernel stack,
* this returns 0.
*/
unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
{
unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
addr += n;
if (regs_within_kernel_stack(regs, (unsigned long)addr))
return *addr;
else
return 0;
}
/*
* this routine will get a word off of the processes privileged stack.
* the offset is how far from the base addr as stored in the THREAD.
* this routine assumes that all the privileged stacks are in our
* data space.
*/
static inline long get_user_reg(struct task_struct *task, int offset)
{
return task_pt_regs(task)->uregs[offset];
}
/*
* this routine will put a word on the processes privileged stack.
* the offset is how far from the base addr as stored in the THREAD.
* this routine assumes that all the privileged stacks are in our
* data space.
*/
static inline int
put_user_reg(struct task_struct *task, int offset, long data)
{
struct pt_regs newregs, *regs = task_pt_regs(task);
int ret = -EINVAL;
newregs = *regs;
newregs.uregs[offset] = data;
if (valid_user_regs(&newregs)) {
regs->uregs[offset] = data;
ret = 0;
}
return ret;
}
/*
* Called by kernel/ptrace.c when detaching..
*/
void ptrace_disable(struct task_struct *child)
{
/* Nothing to do. */
}
/*
* Handle hitting a breakpoint.
*/
void ptrace_break(struct pt_regs *regs)
{
force_sig_fault(SIGTRAP, TRAP_BRKPT,
(void __user *)instruction_pointer(regs));
}
static int break_trap(struct pt_regs *regs, unsigned int instr)
{
ptrace_break(regs);
return 0;
}
static struct undef_hook arm_break_hook = {
.instr_mask = 0x0fffffff,
.instr_val = 0x07f001f0,
.cpsr_mask = PSR_T_BIT,
.cpsr_val = 0,
.fn = break_trap,
};
static struct undef_hook thumb_break_hook = {
.instr_mask = 0xffffffff,
.instr_val = 0x0000de01,
.cpsr_mask = PSR_T_BIT,
.cpsr_val = PSR_T_BIT,
.fn = break_trap,
};
static struct undef_hook thumb2_break_hook = {
.instr_mask = 0xffffffff,
.instr_val = 0xf7f0a000,
.cpsr_mask = PSR_T_BIT,
.cpsr_val = PSR_T_BIT,
.fn = break_trap,
};
static int __init ptrace_break_init(void)
{
register_undef_hook(&arm_break_hook);
register_undef_hook(&thumb_break_hook);
register_undef_hook(&thumb2_break_hook);
return 0;
}
core_initcall(ptrace_break_init);
/*
* Read the word at offset "off" into the "struct user". We
* actually access the pt_regs stored on the kernel stack.
*/
static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
unsigned long __user *ret)
{
unsigned long tmp;
if (off & 3)
return -EIO;
tmp = 0;
if (off == PT_TEXT_ADDR)
tmp = tsk->mm->start_code;
else if (off == PT_DATA_ADDR)
tmp = tsk->mm->start_data;
else if (off == PT_TEXT_END_ADDR)
tmp = tsk->mm->end_code;
else if (off < sizeof(struct pt_regs))
tmp = get_user_reg(tsk, off >> 2);
else if (off >= sizeof(struct user))
return -EIO;
return put_user(tmp, ret);
}
/*
* Write the word at offset "off" into "struct user". We
* actually access the pt_regs stored on the kernel stack.
*/
static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
unsigned long val)
{
if (off & 3 || off >= sizeof(struct user))
return -EIO;
if (off >= sizeof(struct pt_regs))
return 0;
return put_user_reg(tsk, off >> 2, val);
}
#ifdef CONFIG_IWMMXT
/*
* Get the child iWMMXt state.
*/
static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp)
{
struct thread_info *thread = task_thread_info(tsk);
if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
return -ENODATA;
iwmmxt_task_disable(thread); /* force it to ram */
return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE)
? -EFAULT : 0;
}
/*
* Set the child iWMMXt state.
*/
static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp)
{
struct thread_info *thread = task_thread_info(tsk);
if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
return -EACCES;
iwmmxt_task_release(thread); /* force a reload */
return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE)
? -EFAULT : 0;
}
#endif
#ifdef CONFIG_HAVE_HW_BREAKPOINT
/*
* Convert a virtual register number into an index for a thread_info
* breakpoint array. Breakpoints are identified using positive numbers
* whilst watchpoints are negative. The registers are laid out as pairs
* of (address, control), each pair mapping to a unique hw_breakpoint struct.
* Register 0 is reserved for describing resource information.
*/
static int ptrace_hbp_num_to_idx(long num)
{
if (num < 0)
num = (ARM_MAX_BRP << 1) - num;
return (num - 1) >> 1;
}
/*
* Returns the virtual register number for the address of the
* breakpoint at index idx.
*/
static long ptrace_hbp_idx_to_num(int idx)
{
long mid = ARM_MAX_BRP << 1;
long num = (idx << 1) + 1;
return num > mid ? mid - num : num;
}
/*
* Handle hitting a HW-breakpoint.
*/
static void ptrace_hbptriggered(struct perf_event *bp,
struct perf_sample_data *data,
struct pt_regs *regs)
{
struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
long num;
int i;
for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
if (current->thread.debug.hbp[i] == bp)
break;
num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
force_sig_ptrace_errno_trap((int)num, (void __user *)(bkpt->trigger));
}
/*
* Set ptrace breakpoint pointers to zero for this task.
* This is required in order to prevent child processes from unregistering
* breakpoints held by their parent.
*/
void clear_ptrace_hw_breakpoint(struct task_struct *tsk)
{
memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp));
}
/*
* Unregister breakpoints from this task and reset the pointers in
* the thread_struct.
*/
void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
{
int i;
struct thread_struct *t = &tsk->thread;
for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) {
if (t->debug.hbp[i]) {
unregister_hw_breakpoint(t->debug.hbp[i]);
t->debug.hbp[i] = NULL;
}
}
}
static u32 ptrace_get_hbp_resource_info(void)
{
u8 num_brps, num_wrps, debug_arch, wp_len;
u32 reg = 0;
num_brps = hw_breakpoint_slots(TYPE_INST);
num_wrps = hw_breakpoint_slots(TYPE_DATA);
debug_arch = arch_get_debug_arch();
wp_len = arch_get_max_wp_len();
reg |= debug_arch;
reg <<= 8;
reg |= wp_len;
reg <<= 8;
reg |= num_wrps;
reg <<= 8;
reg |= num_brps;
return reg;
}
static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
{
struct perf_event_attr attr;
ptrace_breakpoint_init(&attr);
/* Initialise fields to sane defaults. */
attr.bp_addr = 0;
attr.bp_len = HW_BREAKPOINT_LEN_4;
attr.bp_type = type;
attr.disabled = 1;
return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
tsk);
}
static int ptrace_gethbpregs(struct task_struct *tsk, long num,
unsigned long __user *data)
{
u32 reg;
int idx, ret = 0;
struct perf_event *bp;
struct arch_hw_breakpoint_ctrl arch_ctrl;
if (num == 0) {
reg = ptrace_get_hbp_resource_info();
} else {
idx = ptrace_hbp_num_to_idx(num);
if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
ret = -EINVAL;
goto out;
}
bp = tsk->thread.debug.hbp[idx];
if (!bp) {
reg = 0;
goto put;
}
arch_ctrl = counter_arch_bp(bp)->ctrl;
/*
* Fix up the len because we may have adjusted it
* to compensate for an unaligned address.
*/
while (!(arch_ctrl.len & 0x1))
arch_ctrl.len >>= 1;
if (num & 0x1)
reg = bp->attr.bp_addr;
else
reg = encode_ctrl_reg(arch_ctrl);
}
put:
if (put_user(reg, data))
ret = -EFAULT;
out:
return ret;
}
static int ptrace_sethbpregs(struct task_struct *tsk, long num,
unsigned long __user *data)
{
int idx, gen_len, gen_type, implied_type, ret = 0;
u32 user_val;
struct perf_event *bp;
struct arch_hw_breakpoint_ctrl ctrl;
struct perf_event_attr attr;
if (num == 0)
goto out;
else if (num < 0)
implied_type = HW_BREAKPOINT_RW;
else
implied_type = HW_BREAKPOINT_X;
idx = ptrace_hbp_num_to_idx(num);
if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
ret = -EINVAL;
goto out;
}
if (get_user(user_val, data)) {
ret = -EFAULT;
goto out;
}
bp = tsk->thread.debug.hbp[idx];
if (!bp) {
bp = ptrace_hbp_create(tsk, implied_type);
if (IS_ERR(bp)) {
ret = PTR_ERR(bp);
goto out;
}
tsk->thread.debug.hbp[idx] = bp;
}
attr = bp->attr;
if (num & 0x1) {
/* Address */
attr.bp_addr = user_val;
} else {
/* Control */
decode_ctrl_reg(user_val, &ctrl);
ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type);
if (ret)
goto out;
if ((gen_type & implied_type) != gen_type) {
ret = -EINVAL;
goto out;
}
attr.bp_len = gen_len;
attr.bp_type = gen_type;
attr.disabled = !ctrl.enabled;
}
ret = modify_user_hw_breakpoint(bp, &attr);
out:
return ret;
}
#endif
/* regset get/set implementations */
static int gpr_get(struct task_struct *target,
const struct user_regset *regset,
struct membuf to)
{
return membuf_write(&to, task_pt_regs(target), sizeof(struct pt_regs));
}
static int gpr_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;
struct pt_regs newregs = *task_pt_regs(target);
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&newregs,
0, sizeof(newregs));
if (ret)
return ret;
if (!valid_user_regs(&newregs))
return -EINVAL;
*task_pt_regs(target) = newregs;
return 0;
}
static int fpa_get(struct task_struct *target,
const struct user_regset *regset,
struct membuf to)
{
return membuf_write(&to, &task_thread_info(target)->fpstate,
sizeof(struct user_fp));
}
static int fpa_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
struct thread_info *thread = task_thread_info(target);
return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&thread->fpstate,
0, sizeof(struct user_fp));
}
#ifdef CONFIG_VFP
/*
* VFP register get/set implementations.
*
* With respect to the kernel, struct user_fp is divided into three chunks:
* 16 or 32 real VFP registers (d0-d15 or d0-31)
* These are transferred to/from the real registers in the task's
* vfp_hard_struct. The number of registers depends on the kernel
* configuration.
*
* 16 or 0 fake VFP registers (d16-d31 or empty)
* i.e., the user_vfp structure has space for 32 registers even if
* the kernel doesn't have them all.
*
* vfp_get() reads this chunk as zero where applicable
* vfp_set() ignores this chunk
*
* 1 word for the FPSCR
*/
static int vfp_get(struct task_struct *target,
const struct user_regset *regset,
struct membuf to)
{
struct thread_info *thread = task_thread_info(target);
struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
vfp_sync_hwstate(thread);
membuf_write(&to, vfp->fpregs, sizeof(vfp->fpregs));
membuf_zero(&to, user_fpscr_offset - sizeof(vfp->fpregs));
return membuf_store(&to, vfp->fpscr);
}
/*
* For vfp_set() a read-modify-write is done on the VFP registers,
* in order to avoid writing back a half-modified set of registers on
* failure.
*/
static int vfp_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;
struct thread_info *thread = task_thread_info(target);
struct vfp_hard_struct new_vfp;
const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
vfp_sync_hwstate(thread);
new_vfp = thread->vfpstate.hard;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&new_vfp.fpregs,
user_fpregs_offset,
user_fpregs_offset + sizeof(new_vfp.fpregs));
if (ret)
return ret;
user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
user_fpregs_offset + sizeof(new_vfp.fpregs),
user_fpscr_offset);
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&new_vfp.fpscr,
user_fpscr_offset,
user_fpscr_offset + sizeof(new_vfp.fpscr));
if (ret)
return ret;
thread->vfpstate.hard = new_vfp;
vfp_flush_hwstate(thread);
return 0;
}
#endif /* CONFIG_VFP */
enum arm_regset {
REGSET_GPR,
REGSET_FPR,
#ifdef CONFIG_VFP
REGSET_VFP,
#endif
};
static const struct user_regset arm_regsets[] = {
[REGSET_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = ELF_NGREG,
.size = sizeof(u32),
.align = sizeof(u32),
.regset_get = gpr_get,
.set = gpr_set
},
[REGSET_FPR] = {
/*
* For the FPA regs in fpstate, the real fields are a mixture
* of sizes, so pretend that the registers are word-sized:
*/
.core_note_type = NT_PRFPREG,
.n = sizeof(struct user_fp) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
.regset_get = fpa_get,
.set = fpa_set
},
#ifdef CONFIG_VFP
[REGSET_VFP] = {
/*
* Pretend that the VFP regs are word-sized, since the FPSCR is
* a single word dangling at the end of struct user_vfp:
*/
.core_note_type = NT_ARM_VFP,
.n = ARM_VFPREGS_SIZE / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
.regset_get = vfp_get,
.set = vfp_set
},
#endif /* CONFIG_VFP */
};
static const struct user_regset_view user_arm_view = {
.name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
.regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets)
};
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
return &user_arm_view;
}
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) {
case PTRACE_PEEKUSR:
ret = ptrace_read_user(child, addr, datap);
break;
case PTRACE_POKEUSR:
ret = ptrace_write_user(child, addr, data);
break;
case PTRACE_GETREGS:
ret = copy_regset_to_user(child,
&user_arm_view, REGSET_GPR,
0, sizeof(struct pt_regs),
datap);
break;
case PTRACE_SETREGS:
ret = copy_regset_from_user(child,
&user_arm_view, REGSET_GPR,
0, sizeof(struct pt_regs),
datap);
break;
case PTRACE_GETFPREGS:
ret = copy_regset_to_user(child,
&user_arm_view, REGSET_FPR,
0, sizeof(union fp_state),
datap);
break;
case PTRACE_SETFPREGS:
ret = copy_regset_from_user(child,
&user_arm_view, REGSET_FPR,
0, sizeof(union fp_state),
datap);
break;
#ifdef CONFIG_IWMMXT
case PTRACE_GETWMMXREGS:
ret = ptrace_getwmmxregs(child, datap);
break;
case PTRACE_SETWMMXREGS:
ret = ptrace_setwmmxregs(child, datap);
break;
#endif
case PTRACE_GET_THREAD_AREA:
ret = put_user(task_thread_info(child)->tp_value[0],
datap);
break;
case PTRACE_SET_SYSCALL:
if (data != -1)
data &= __NR_SYSCALL_MASK;
task_thread_info(child)->abi_syscall = data;
ret = 0;
break;
#ifdef CONFIG_VFP
case PTRACE_GETVFPREGS:
ret = copy_regset_to_user(child,
&user_arm_view, REGSET_VFP,
0, ARM_VFPREGS_SIZE,
datap);
break;
case PTRACE_SETVFPREGS:
ret = copy_regset_from_user(child,
&user_arm_view, REGSET_VFP,
0, ARM_VFPREGS_SIZE,
datap);
break;
#endif
#ifdef CONFIG_HAVE_HW_BREAKPOINT
case PTRACE_GETHBPREGS:
ret = ptrace_gethbpregs(child, addr,
(unsigned long __user *)data);
break;
case PTRACE_SETHBPREGS:
ret = ptrace_sethbpregs(child, addr,
(unsigned long __user *)data);
break;
#endif
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
enum ptrace_syscall_dir {
PTRACE_SYSCALL_ENTER = 0,
PTRACE_SYSCALL_EXIT,
};
static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir)
{
unsigned long ip;
/*
* IP is used to denote syscall entry/exit:
* IP = 0 -> entry, =1 -> exit
*/
ip = regs->ARM_ip;
regs->ARM_ip = dir;
if (dir == PTRACE_SYSCALL_EXIT)
ptrace_report_syscall_exit(regs, 0);
else if (ptrace_report_syscall_entry(regs))
current_thread_info()->abi_syscall = -1;
regs->ARM_ip = ip;
}
asmlinkage int syscall_trace_enter(struct pt_regs *regs)
{
int scno;
if (test_thread_flag(TIF_SYSCALL_TRACE))
report_syscall(regs, PTRACE_SYSCALL_ENTER);
/* Do seccomp after ptrace; syscall may have changed. */
#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
if (secure_computing() == -1)
return -1;
#else
/* XXX: remove this once OABI gets fixed */
secure_computing_strict(syscall_get_nr(current, regs));
#endif
/* Tracer or seccomp may have changed syscall. */
scno = syscall_get_nr(current, regs);
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_enter(regs, scno);
audit_syscall_entry(scno, regs->ARM_r0, regs->ARM_r1, regs->ARM_r2,
regs->ARM_r3);
return scno;
}
asmlinkage void syscall_trace_exit(struct pt_regs *regs)
{
/*
* Audit the syscall before anything else, as a debugger may
* come in and change the current registers.
*/
audit_syscall_exit(regs);
/*
* Note that we haven't updated the ->syscall field for the
* current thread. This isn't a problem because it will have
* been set on syscall entry and there hasn't been an opportunity
* for a PTRACE_SET_SYSCALL since then.
*/
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_exit(regs, regs_return_value(regs));
if (test_thread_flag(TIF_SYSCALL_TRACE))
report_syscall(regs, PTRACE_SYSCALL_EXIT);
}