blob: 34d915b6974be24747cefed9bbff8b6c04882444 [file] [log] [blame]
/*
* Based on arch/arm/kernel/ptrace.c
*
* By Ross Biro 1/23/92
* edited by Linus Torvalds
* ARM modifications Copyright (C) 2000 Russell King
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/audit.h>
#include <linux/compat.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/nospec.h>
#include <linux/smp.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/seccomp.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/tracehook.h>
#include <linux/elf.h>
#include <asm/compat.h>
#include <asm/debug-monitors.h>
#include <asm/pgtable.h>
#include <asm/stacktrace.h>
#include <asm/syscall.h>
#include <asm/traps.h>
#include <asm/system_misc.h>
#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>
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}
#define GPR_OFFSET_NAME(r) \
{.name = "x" #r, .offset = offsetof(struct pt_regs, regs[r])}
static const struct pt_regs_offset regoffset_table[] = {
GPR_OFFSET_NAME(0),
GPR_OFFSET_NAME(1),
GPR_OFFSET_NAME(2),
GPR_OFFSET_NAME(3),
GPR_OFFSET_NAME(4),
GPR_OFFSET_NAME(5),
GPR_OFFSET_NAME(6),
GPR_OFFSET_NAME(7),
GPR_OFFSET_NAME(8),
GPR_OFFSET_NAME(9),
GPR_OFFSET_NAME(10),
GPR_OFFSET_NAME(11),
GPR_OFFSET_NAME(12),
GPR_OFFSET_NAME(13),
GPR_OFFSET_NAME(14),
GPR_OFFSET_NAME(15),
GPR_OFFSET_NAME(16),
GPR_OFFSET_NAME(17),
GPR_OFFSET_NAME(18),
GPR_OFFSET_NAME(19),
GPR_OFFSET_NAME(20),
GPR_OFFSET_NAME(21),
GPR_OFFSET_NAME(22),
GPR_OFFSET_NAME(23),
GPR_OFFSET_NAME(24),
GPR_OFFSET_NAME(25),
GPR_OFFSET_NAME(26),
GPR_OFFSET_NAME(27),
GPR_OFFSET_NAME(28),
GPR_OFFSET_NAME(29),
GPR_OFFSET_NAME(30),
{.name = "lr", .offset = offsetof(struct pt_regs, regs[30])},
REG_OFFSET_NAME(sp),
REG_OFFSET_NAME(pc),
REG_OFFSET_NAME(pstate),
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_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.
*/
static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
{
return ((addr & ~(THREAD_SIZE - 1)) ==
(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))) ||
on_irq_stack(addr);
}
/**
* 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;
}
/*
* TODO: does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/*
* Called by kernel/ptrace.c when detaching..
*/
void ptrace_disable(struct task_struct *child)
{
/*
* This would be better off in core code, but PTRACE_DETACH has
* grown its fair share of arch-specific worts and changing it
* is likely to cause regressions on obscure architectures.
*/
user_disable_single_step(child);
}
#ifdef CONFIG_HAVE_HW_BREAKPOINT
/*
* 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);
siginfo_t info = {
.si_signo = SIGTRAP,
.si_errno = 0,
.si_code = TRAP_HWBKPT,
.si_addr = (void __user *)(bkpt->trigger),
};
#ifdef CONFIG_COMPAT
int i;
if (!is_compat_task())
goto send_sig;
for (i = 0; i < ARM_MAX_BRP; ++i) {
if (current->thread.debug.hbp_break[i] == bp) {
info.si_errno = (i << 1) + 1;
break;
}
}
for (i = 0; i < ARM_MAX_WRP; ++i) {
if (current->thread.debug.hbp_watch[i] == bp) {
info.si_errno = -((i << 1) + 1);
break;
}
}
send_sig:
#endif
force_sig_info(SIGTRAP, &info, current);
}
/*
* 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_BRP; i++) {
if (t->debug.hbp_break[i]) {
unregister_hw_breakpoint(t->debug.hbp_break[i]);
t->debug.hbp_break[i] = NULL;
}
}
for (i = 0; i < ARM_MAX_WRP; i++) {
if (t->debug.hbp_watch[i]) {
unregister_hw_breakpoint(t->debug.hbp_watch[i]);
t->debug.hbp_watch[i] = NULL;
}
}
}
void ptrace_hw_copy_thread(struct task_struct *tsk)
{
memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
}
static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
struct task_struct *tsk,
unsigned long idx)
{
struct perf_event *bp = ERR_PTR(-EINVAL);
switch (note_type) {
case NT_ARM_HW_BREAK:
if (idx >= ARM_MAX_BRP)
goto out;
idx = array_index_nospec(idx, ARM_MAX_BRP);
bp = tsk->thread.debug.hbp_break[idx];
break;
case NT_ARM_HW_WATCH:
if (idx >= ARM_MAX_WRP)
goto out;
idx = array_index_nospec(idx, ARM_MAX_WRP);
bp = tsk->thread.debug.hbp_watch[idx];
break;
}
out:
return bp;
}
static int ptrace_hbp_set_event(unsigned int note_type,
struct task_struct *tsk,
unsigned long idx,
struct perf_event *bp)
{
int err = -EINVAL;
switch (note_type) {
case NT_ARM_HW_BREAK:
if (idx >= ARM_MAX_BRP)
goto out;
idx = array_index_nospec(idx, ARM_MAX_BRP);
tsk->thread.debug.hbp_break[idx] = bp;
err = 0;
break;
case NT_ARM_HW_WATCH:
if (idx >= ARM_MAX_WRP)
goto out;
idx = array_index_nospec(idx, ARM_MAX_WRP);
tsk->thread.debug.hbp_watch[idx] = bp;
err = 0;
break;
}
out:
return err;
}
static struct perf_event *ptrace_hbp_create(unsigned int note_type,
struct task_struct *tsk,
unsigned long idx)
{
struct perf_event *bp;
struct perf_event_attr attr;
int err, type;
switch (note_type) {
case NT_ARM_HW_BREAK:
type = HW_BREAKPOINT_X;
break;
case NT_ARM_HW_WATCH:
type = HW_BREAKPOINT_RW;
break;
default:
return ERR_PTR(-EINVAL);
}
ptrace_breakpoint_init(&attr);
/*
* Initialise fields to sane defaults
* (i.e. values that will pass validation).
*/
attr.bp_addr = 0;
attr.bp_len = HW_BREAKPOINT_LEN_4;
attr.bp_type = type;
attr.disabled = 1;
bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
if (IS_ERR(bp))
return bp;
err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
if (err)
return ERR_PTR(err);
return bp;
}
static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
struct arch_hw_breakpoint_ctrl ctrl,
struct perf_event_attr *attr)
{
int err, len, type, offset, disabled = !ctrl.enabled;
attr->disabled = disabled;
if (disabled)
return 0;
err = arch_bp_generic_fields(ctrl, &len, &type, &offset);
if (err)
return err;
switch (note_type) {
case NT_ARM_HW_BREAK:
if ((type & HW_BREAKPOINT_X) != type)
return -EINVAL;
break;
case NT_ARM_HW_WATCH:
if ((type & HW_BREAKPOINT_RW) != type)
return -EINVAL;
break;
default:
return -EINVAL;
}
attr->bp_len = len;
attr->bp_type = type;
attr->bp_addr += offset;
return 0;
}
static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
{
u8 num;
u32 reg = 0;
switch (note_type) {
case NT_ARM_HW_BREAK:
num = hw_breakpoint_slots(TYPE_INST);
break;
case NT_ARM_HW_WATCH:
num = hw_breakpoint_slots(TYPE_DATA);
break;
default:
return -EINVAL;
}
reg |= debug_monitors_arch();
reg <<= 8;
reg |= num;
*info = reg;
return 0;
}
static int ptrace_hbp_get_ctrl(unsigned int note_type,
struct task_struct *tsk,
unsigned long idx,
u32 *ctrl)
{
struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
if (IS_ERR(bp))
return PTR_ERR(bp);
*ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
return 0;
}
static int ptrace_hbp_get_addr(unsigned int note_type,
struct task_struct *tsk,
unsigned long idx,
u64 *addr)
{
struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
if (IS_ERR(bp))
return PTR_ERR(bp);
*addr = bp ? counter_arch_bp(bp)->address : 0;
return 0;
}
static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
struct task_struct *tsk,
unsigned long idx)
{
struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
if (!bp)
bp = ptrace_hbp_create(note_type, tsk, idx);
return bp;
}
static int ptrace_hbp_set_ctrl(unsigned int note_type,
struct task_struct *tsk,
unsigned long idx,
u32 uctrl)
{
int err;
struct perf_event *bp;
struct perf_event_attr attr;
struct arch_hw_breakpoint_ctrl ctrl;
bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
if (IS_ERR(bp)) {
err = PTR_ERR(bp);
return err;
}
attr = bp->attr;
decode_ctrl_reg(uctrl, &ctrl);
err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
if (err)
return err;
return modify_user_hw_breakpoint(bp, &attr);
}
static int ptrace_hbp_set_addr(unsigned int note_type,
struct task_struct *tsk,
unsigned long idx,
u64 addr)
{
int err;
struct perf_event *bp;
struct perf_event_attr attr;
bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
if (IS_ERR(bp)) {
err = PTR_ERR(bp);
return err;
}
attr = bp->attr;
attr.bp_addr = addr;
err = modify_user_hw_breakpoint(bp, &attr);
return err;
}
#define PTRACE_HBP_ADDR_SZ sizeof(u64)
#define PTRACE_HBP_CTRL_SZ sizeof(u32)
#define PTRACE_HBP_PAD_SZ sizeof(u32)
static int hw_break_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
unsigned int note_type = regset->core_note_type;
int ret, idx = 0, offset, limit;
u32 info, ctrl;
u64 addr;
/* Resource info */
ret = ptrace_hbp_get_resource_info(note_type, &info);
if (ret)
return ret;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
sizeof(info));
if (ret)
return ret;
/* Pad */
offset = offsetof(struct user_hwdebug_state, pad);
ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
offset + PTRACE_HBP_PAD_SZ);
if (ret)
return ret;
/* (address, ctrl) registers */
offset = offsetof(struct user_hwdebug_state, dbg_regs);
limit = regset->n * regset->size;
while (count && offset < limit) {
ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
if (ret)
return ret;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
offset, offset + PTRACE_HBP_ADDR_SZ);
if (ret)
return ret;
offset += PTRACE_HBP_ADDR_SZ;
ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
if (ret)
return ret;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
offset, offset + PTRACE_HBP_CTRL_SZ);
if (ret)
return ret;
offset += PTRACE_HBP_CTRL_SZ;
ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
offset,
offset + PTRACE_HBP_PAD_SZ);
if (ret)
return ret;
offset += PTRACE_HBP_PAD_SZ;
idx++;
}
return 0;
}
static int hw_break_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
unsigned int note_type = regset->core_note_type;
int ret, idx = 0, offset, limit;
u32 ctrl;
u64 addr;
/* Resource info and pad */
offset = offsetof(struct user_hwdebug_state, dbg_regs);
ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
if (ret)
return ret;
/* (address, ctrl) registers */
limit = regset->n * regset->size;
while (count && offset < limit) {
if (count < PTRACE_HBP_ADDR_SZ)
return -EINVAL;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
offset, offset + PTRACE_HBP_ADDR_SZ);
if (ret)
return ret;
ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
if (ret)
return ret;
offset += PTRACE_HBP_ADDR_SZ;
if (!count)
break;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
offset, offset + PTRACE_HBP_CTRL_SZ);
if (ret)
return ret;
ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
if (ret)
return ret;
offset += PTRACE_HBP_CTRL_SZ;
ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
offset,
offset + PTRACE_HBP_PAD_SZ);
if (ret)
return ret;
offset += PTRACE_HBP_PAD_SZ;
idx++;
}
return 0;
}
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
static int gpr_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
}
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 user_pt_regs newregs = task_pt_regs(target)->user_regs;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
if (ret)
return ret;
if (!valid_user_regs(&newregs, target))
return -EINVAL;
task_pt_regs(target)->user_regs = newregs;
return 0;
}
/*
* TODO: update fp accessors for lazy context switching (sync/flush hwstate)
*/
static int fpr_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
struct user_fpsimd_state *uregs;
uregs = &target->thread.fpsimd_state.user_fpsimd;
if (target == current)
fpsimd_preserve_current_state();
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
}
static int fpr_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 user_fpsimd_state newstate =
target->thread.fpsimd_state.user_fpsimd;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
if (ret)
return ret;
target->thread.fpsimd_state.user_fpsimd = newstate;
fpsimd_flush_task_state(target);
return ret;
}
static int tls_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
unsigned long *tls = &target->thread.tp_value;
if (target == current)
tls_preserve_current_state();
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
}
static int tls_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;
unsigned long tls = target->thread.tp_value;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
if (ret)
return ret;
target->thread.tp_value = tls;
return ret;
}
static int system_call_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
int syscallno = task_pt_regs(target)->syscallno;
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&syscallno, 0, -1);
}
static int system_call_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
int syscallno = task_pt_regs(target)->syscallno;
int ret;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1);
if (ret)
return ret;
task_pt_regs(target)->syscallno = syscallno;
return ret;
}
enum aarch64_regset {
REGSET_GPR,
REGSET_FPR,
REGSET_TLS,
#ifdef CONFIG_HAVE_HW_BREAKPOINT
REGSET_HW_BREAK,
REGSET_HW_WATCH,
#endif
REGSET_SYSTEM_CALL,
};
static const struct user_regset aarch64_regsets[] = {
[REGSET_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = sizeof(struct user_pt_regs) / sizeof(u64),
.size = sizeof(u64),
.align = sizeof(u64),
.get = gpr_get,
.set = gpr_set
},
[REGSET_FPR] = {
.core_note_type = NT_PRFPREG,
.n = sizeof(struct user_fpsimd_state) / sizeof(u32),
/*
* We pretend we have 32-bit registers because the fpsr and
* fpcr are 32-bits wide.
*/
.size = sizeof(u32),
.align = sizeof(u32),
.get = fpr_get,
.set = fpr_set
},
[REGSET_TLS] = {
.core_note_type = NT_ARM_TLS,
.n = 1,
.size = sizeof(void *),
.align = sizeof(void *),
.get = tls_get,
.set = tls_set,
},
#ifdef CONFIG_HAVE_HW_BREAKPOINT
[REGSET_HW_BREAK] = {
.core_note_type = NT_ARM_HW_BREAK,
.n = sizeof(struct user_hwdebug_state) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
.get = hw_break_get,
.set = hw_break_set,
},
[REGSET_HW_WATCH] = {
.core_note_type = NT_ARM_HW_WATCH,
.n = sizeof(struct user_hwdebug_state) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
.get = hw_break_get,
.set = hw_break_set,
},
#endif
[REGSET_SYSTEM_CALL] = {
.core_note_type = NT_ARM_SYSTEM_CALL,
.n = 1,
.size = sizeof(int),
.align = sizeof(int),
.get = system_call_get,
.set = system_call_set,
},
};
static const struct user_regset_view user_aarch64_view = {
.name = "aarch64", .e_machine = EM_AARCH64,
.regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
};
#ifdef CONFIG_COMPAT
#include <linux/compat.h>
enum compat_regset {
REGSET_COMPAT_GPR,
REGSET_COMPAT_VFP,
};
static int compat_gpr_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
int ret = 0;
unsigned int i, start, num_regs;
/* Calculate the number of AArch32 registers contained in count */
num_regs = count / regset->size;
/* Convert pos into an register number */
start = pos / regset->size;
if (start + num_regs > regset->n)
return -EIO;
for (i = 0; i < num_regs; ++i) {
unsigned int idx = start + i;
compat_ulong_t reg;
switch (idx) {
case 15:
reg = task_pt_regs(target)->pc;
break;
case 16:
reg = task_pt_regs(target)->pstate;
break;
case 17:
reg = task_pt_regs(target)->orig_x0;
break;
default:
reg = task_pt_regs(target)->regs[idx];
}
if (kbuf) {
memcpy(kbuf, &reg, sizeof(reg));
kbuf += sizeof(reg);
} else {
ret = copy_to_user(ubuf, &reg, sizeof(reg));
if (ret) {
ret = -EFAULT;
break;
}
ubuf += sizeof(reg);
}
}
return ret;
}
static int compat_gpr_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
struct pt_regs newregs;
int ret = 0;
unsigned int i, start, num_regs;
/* Calculate the number of AArch32 registers contained in count */
num_regs = count / regset->size;
/* Convert pos into an register number */
start = pos / regset->size;
if (start + num_regs > regset->n)
return -EIO;
newregs = *task_pt_regs(target);
for (i = 0; i < num_regs; ++i) {
unsigned int idx = start + i;
compat_ulong_t reg;
if (kbuf) {
memcpy(&reg, kbuf, sizeof(reg));
kbuf += sizeof(reg);
} else {
ret = copy_from_user(&reg, ubuf, sizeof(reg));
if (ret) {
ret = -EFAULT;
break;
}
ubuf += sizeof(reg);
}
switch (idx) {
case 15:
newregs.pc = reg;
break;
case 16:
newregs.pstate = reg;
break;
case 17:
newregs.orig_x0 = reg;
break;
default:
newregs.regs[idx] = reg;
}
}
if (valid_user_regs(&newregs.user_regs, target))
*task_pt_regs(target) = newregs;
else
ret = -EINVAL;
return ret;
}
static int compat_vfp_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
struct user_fpsimd_state *uregs;
compat_ulong_t fpscr;
int ret, vregs_end_pos;
uregs = &target->thread.fpsimd_state.user_fpsimd;
if (target == current)
fpsimd_preserve_current_state();
/*
* The VFP registers are packed into the fpsimd_state, so they all sit
* nicely together for us. We just need to create the fpscr separately.
*/
vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs,
0, vregs_end_pos);
if (count && !ret) {
fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
(uregs->fpcr & VFP_FPSCR_CTRL_MASK);
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &fpscr,
vregs_end_pos, VFP_STATE_SIZE);
}
return ret;
}
static int compat_vfp_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
struct user_fpsimd_state *uregs;
compat_ulong_t fpscr;
int ret, vregs_end_pos;
uregs = &target->thread.fpsimd_state.user_fpsimd;
vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
vregs_end_pos);
if (count && !ret) {
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpscr,
vregs_end_pos, VFP_STATE_SIZE);
if (!ret) {
uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
}
}
fpsimd_flush_task_state(target);
return ret;
}
static int compat_tls_get(struct task_struct *target,
const struct user_regset *regset, unsigned int pos,
unsigned int count, void *kbuf, void __user *ubuf)
{
compat_ulong_t tls = (compat_ulong_t)target->thread.tp_value;
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
}
static int compat_tls_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;
compat_ulong_t tls = target->thread.tp_value;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
if (ret)
return ret;
target->thread.tp_value = tls;
return ret;
}
static const struct user_regset aarch32_regsets[] = {
[REGSET_COMPAT_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = COMPAT_ELF_NGREG,
.size = sizeof(compat_elf_greg_t),
.align = sizeof(compat_elf_greg_t),
.get = compat_gpr_get,
.set = compat_gpr_set
},
[REGSET_COMPAT_VFP] = {
.core_note_type = NT_ARM_VFP,
.n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
.size = sizeof(compat_ulong_t),
.align = sizeof(compat_ulong_t),
.get = compat_vfp_get,
.set = compat_vfp_set
},
};
static const struct user_regset_view user_aarch32_view = {
.name = "aarch32", .e_machine = EM_ARM,
.regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
};
static const struct user_regset aarch32_ptrace_regsets[] = {
[REGSET_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = COMPAT_ELF_NGREG,
.size = sizeof(compat_elf_greg_t),
.align = sizeof(compat_elf_greg_t),
.get = compat_gpr_get,
.set = compat_gpr_set
},
[REGSET_FPR] = {
.core_note_type = NT_ARM_VFP,
.n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
.size = sizeof(compat_ulong_t),
.align = sizeof(compat_ulong_t),
.get = compat_vfp_get,
.set = compat_vfp_set
},
[REGSET_TLS] = {
.core_note_type = NT_ARM_TLS,
.n = 1,
.size = sizeof(compat_ulong_t),
.align = sizeof(compat_ulong_t),
.get = compat_tls_get,
.set = compat_tls_set,
},
#ifdef CONFIG_HAVE_HW_BREAKPOINT
[REGSET_HW_BREAK] = {
.core_note_type = NT_ARM_HW_BREAK,
.n = sizeof(struct user_hwdebug_state) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
.get = hw_break_get,
.set = hw_break_set,
},
[REGSET_HW_WATCH] = {
.core_note_type = NT_ARM_HW_WATCH,
.n = sizeof(struct user_hwdebug_state) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
.get = hw_break_get,
.set = hw_break_set,
},
#endif
[REGSET_SYSTEM_CALL] = {
.core_note_type = NT_ARM_SYSTEM_CALL,
.n = 1,
.size = sizeof(int),
.align = sizeof(int),
.get = system_call_get,
.set = system_call_set,
},
};
static const struct user_regset_view user_aarch32_ptrace_view = {
.name = "aarch32", .e_machine = EM_ARM,
.regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets)
};
static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
compat_ulong_t __user *ret)
{
compat_ulong_t tmp;
if (off & 3)
return -EIO;
if (off == COMPAT_PT_TEXT_ADDR)
tmp = tsk->mm->start_code;
else if (off == COMPAT_PT_DATA_ADDR)
tmp = tsk->mm->start_data;
else if (off == COMPAT_PT_TEXT_END_ADDR)
tmp = tsk->mm->end_code;
else if (off < sizeof(compat_elf_gregset_t))
return copy_regset_to_user(tsk, &user_aarch32_view,
REGSET_COMPAT_GPR, off,
sizeof(compat_ulong_t), ret);
else if (off >= COMPAT_USER_SZ)
return -EIO;
else
tmp = 0;
return put_user(tmp, ret);
}
static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
compat_ulong_t val)
{
int ret;
mm_segment_t old_fs = get_fs();
if (off & 3 || off >= COMPAT_USER_SZ)
return -EIO;
if (off >= sizeof(compat_elf_gregset_t))
return 0;
set_fs(KERNEL_DS);
ret = copy_regset_from_user(tsk, &user_aarch32_view,
REGSET_COMPAT_GPR, off,
sizeof(compat_ulong_t),
&val);
set_fs(old_fs);
return ret;
}
#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 compat_ptrace_hbp_num_to_idx(compat_long_t num)
{
return (abs(num) - 1) >> 1;
}
static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
{
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 = debug_monitors_arch();
wp_len = 8;
reg |= debug_arch;
reg <<= 8;
reg |= wp_len;
reg <<= 8;
reg |= num_wrps;
reg <<= 8;
reg |= num_brps;
*kdata = reg;
return 0;
}
static int compat_ptrace_hbp_get(unsigned int note_type,
struct task_struct *tsk,
compat_long_t num,
u32 *kdata)
{
u64 addr = 0;
u32 ctrl = 0;
int err, idx = compat_ptrace_hbp_num_to_idx(num);;
if (num & 1) {
err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
*kdata = (u32)addr;
} else {
err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
*kdata = ctrl;
}
return err;
}
static int compat_ptrace_hbp_set(unsigned int note_type,
struct task_struct *tsk,
compat_long_t num,
u32 *kdata)
{
u64 addr;
u32 ctrl;
int err, idx = compat_ptrace_hbp_num_to_idx(num);
if (num & 1) {
addr = *kdata;
err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
} else {
ctrl = *kdata;
err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
}
return err;
}
static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
compat_ulong_t __user *data)
{
int ret;
u32 kdata;
/* Watchpoint */
if (num < 0) {
ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
/* Resource info */
} else if (num == 0) {
ret = compat_ptrace_hbp_get_resource_info(&kdata);
/* Breakpoint */
} else {
ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
}
if (!ret)
ret = put_user(kdata, data);
return ret;
}
static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
compat_ulong_t __user *data)
{
int ret;
u32 kdata = 0;
if (num == 0)
return 0;
ret = get_user(kdata, data);
if (ret)
return ret;
if (num < 0)
ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
else
ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
return ret;
}
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
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;
switch (request) {
case PTRACE_PEEKUSR:
ret = compat_ptrace_read_user(child, addr, datap);
break;
case PTRACE_POKEUSR:
ret = compat_ptrace_write_user(child, addr, data);
break;
case COMPAT_PTRACE_GETREGS:
ret = copy_regset_to_user(child,
&user_aarch32_view,
REGSET_COMPAT_GPR,
0, sizeof(compat_elf_gregset_t),
datap);
break;
case COMPAT_PTRACE_SETREGS:
ret = copy_regset_from_user(child,
&user_aarch32_view,
REGSET_COMPAT_GPR,
0, sizeof(compat_elf_gregset_t),
datap);
break;
case COMPAT_PTRACE_GET_THREAD_AREA:
ret = put_user((compat_ulong_t)child->thread.tp_value,
(compat_ulong_t __user *)datap);
break;
case COMPAT_PTRACE_SET_SYSCALL:
task_pt_regs(child)->syscallno = data;
ret = 0;
break;
case COMPAT_PTRACE_GETVFPREGS:
ret = copy_regset_to_user(child,
&user_aarch32_view,
REGSET_COMPAT_VFP,
0, VFP_STATE_SIZE,
datap);
break;
case COMPAT_PTRACE_SETVFPREGS:
ret = copy_regset_from_user(child,
&user_aarch32_view,
REGSET_COMPAT_VFP,
0, VFP_STATE_SIZE,
datap);
break;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
case COMPAT_PTRACE_GETHBPREGS:
ret = compat_ptrace_gethbpregs(child, addr, datap);
break;
case COMPAT_PTRACE_SETHBPREGS:
ret = compat_ptrace_sethbpregs(child, addr, datap);
break;
#endif
default:
ret = compat_ptrace_request(child, request, addr,
data);
break;
}
return ret;
}
#endif /* CONFIG_COMPAT */
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
#ifdef CONFIG_COMPAT
/*
* Core dumping of 32-bit tasks or compat ptrace requests must use the
* user_aarch32_view compatible with arm32. Native ptrace requests on
* 32-bit children use an extended user_aarch32_ptrace_view to allow
* access to the TLS register.
*/
if (is_compat_task())
return &user_aarch32_view;
else if (is_compat_thread(task_thread_info(task)))
return &user_aarch32_ptrace_view;
#endif
return &user_aarch64_view;
}
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
return ptrace_request(child, request, addr, data);
}
enum ptrace_syscall_dir {
PTRACE_SYSCALL_ENTER = 0,
PTRACE_SYSCALL_EXIT,
};
static void tracehook_report_syscall(struct pt_regs *regs,
enum ptrace_syscall_dir dir)
{
int regno;
unsigned long saved_reg;
/*
* A scratch register (ip(r12) on AArch32, x7 on AArch64) is
* used to denote syscall entry/exit:
*/
regno = (is_compat_task() ? 12 : 7);
saved_reg = regs->regs[regno];
regs->regs[regno] = dir;
if (dir == PTRACE_SYSCALL_EXIT)
tracehook_report_syscall_exit(regs, 0);
else if (tracehook_report_syscall_entry(regs))
forget_syscall(regs);
regs->regs[regno] = saved_reg;
}
asmlinkage int syscall_trace_enter(struct pt_regs *regs)
{
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
/* Do the secure computing after ptrace; failures should be fast. */
if (secure_computing(NULL) == -1)
return -1;
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_enter(regs, regs->syscallno);
audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
regs->regs[2], regs->regs[3]);
return regs->syscallno;
}
asmlinkage void syscall_trace_exit(struct pt_regs *regs)
{
audit_syscall_exit(regs);
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_exit(regs, regs_return_value(regs));
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
}
/*
* Bits which are always architecturally RES0 per ARM DDI 0487A.h
* Userspace cannot use these until they have an architectural meaning.
* We also reserve IL for the kernel; SS is handled dynamically.
*/
#define SPSR_EL1_AARCH64_RES0_BITS \
(GENMASK_ULL(63,32) | GENMASK_ULL(27, 22) | GENMASK_ULL(20, 10) | \
GENMASK_ULL(5, 5))
#define SPSR_EL1_AARCH32_RES0_BITS \
(GENMASK_ULL(63,32) | GENMASK_ULL(24, 22) | GENMASK_ULL(20,20))
static int valid_compat_regs(struct user_pt_regs *regs)
{
regs->pstate &= ~SPSR_EL1_AARCH32_RES0_BITS;
if (!system_supports_mixed_endian_el0()) {
if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
regs->pstate |= COMPAT_PSR_E_BIT;
else
regs->pstate &= ~COMPAT_PSR_E_BIT;
}
if (user_mode(regs) && (regs->pstate & PSR_MODE32_BIT) &&
(regs->pstate & COMPAT_PSR_A_BIT) == 0 &&
(regs->pstate & COMPAT_PSR_I_BIT) == 0 &&
(regs->pstate & COMPAT_PSR_F_BIT) == 0) {
return 1;
}
/*
* Force PSR to a valid 32-bit EL0t, preserving the same bits as
* arch/arm.
*/
regs->pstate &= COMPAT_PSR_N_BIT | COMPAT_PSR_Z_BIT |
COMPAT_PSR_C_BIT | COMPAT_PSR_V_BIT |
COMPAT_PSR_Q_BIT | COMPAT_PSR_IT_MASK |
COMPAT_PSR_GE_MASK | COMPAT_PSR_E_BIT |
COMPAT_PSR_T_BIT;
regs->pstate |= PSR_MODE32_BIT;
return 0;
}
static int valid_native_regs(struct user_pt_regs *regs)
{
regs->pstate &= ~SPSR_EL1_AARCH64_RES0_BITS;
if (user_mode(regs) && !(regs->pstate & PSR_MODE32_BIT) &&
(regs->pstate & PSR_D_BIT) == 0 &&
(regs->pstate & PSR_A_BIT) == 0 &&
(regs->pstate & PSR_I_BIT) == 0 &&
(regs->pstate & PSR_F_BIT) == 0) {
return 1;
}
/* Force PSR to a valid 64-bit EL0t */
regs->pstate &= PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT;
return 0;
}
/*
* Are the current registers suitable for user mode? (used to maintain
* security in signal handlers)
*/
int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task)
{
if (!test_tsk_thread_flag(task, TIF_SINGLESTEP))
regs->pstate &= ~DBG_SPSR_SS;
if (is_compat_thread(task_thread_info(task)))
return valid_compat_regs(regs);
else
return valid_native_regs(regs);
}