/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2007 Tensilica Inc.
*
* Joe Taylor <[email protected], [email protected]>
* Chris Zankel <[email protected]>
* Scott Foehner<[email protected]>,
* Kevin Chea
* Marc Gauthier<[email protected]> <[email protected]>
*/
#include <linux/audit.h>
#include <linux/errno.h>
#include <linux/hw_breakpoint.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/perf_event.h>
#include <linux/ptrace.h>
#include <linux/regset.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/seccomp.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/smp.h>
#include <linux/uaccess.h>
#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>
#include <asm/coprocessor.h>
#include <asm/elf.h>
#include <asm/page.h>
#include <asm/ptrace.h>
static int gpr_get(struct task_struct *target,
const struct user_regset *regset,
struct membuf to)
{
struct pt_regs *regs = task_pt_regs(target);
struct user_pt_regs newregs = {
.pc = regs->pc,
.ps = regs->ps & ~(1 << PS_EXCM_BIT),
.lbeg = regs->lbeg,
.lend = regs->lend,
.lcount = regs->lcount,
.sar = regs->sar,
.threadptr = regs->threadptr,
.windowbase = regs->windowbase,
.windowstart = regs->windowstart,
.syscall = regs->syscall,
};
memcpy(newregs.a,
regs->areg + XCHAL_NUM_AREGS - regs->windowbase * 4,
regs->windowbase * 16);
memcpy(newregs.a + regs->windowbase * 4,
regs->areg,
(WSBITS - regs->windowbase) * 16);
return membuf_write(&to, &newregs, sizeof(newregs));
}
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 = {0};
struct pt_regs *regs;
const u32 ps_mask = PS_CALLINC_MASK | PS_OWB_MASK;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
if (ret)
return ret;
if (newregs.windowbase >= XCHAL_NUM_AREGS / 4)
return -EINVAL;
regs = task_pt_regs(target);
regs->pc = newregs.pc;
regs->ps = (regs->ps & ~ps_mask) | (newregs.ps & ps_mask);
regs->lbeg = newregs.lbeg;
regs->lend = newregs.lend;
regs->lcount = newregs.lcount;
regs->sar = newregs.sar;
regs->threadptr = newregs.threadptr;
if (newregs.syscall)
regs->syscall = newregs.syscall;
if (newregs.windowbase != regs->windowbase ||
newregs.windowstart != regs->windowstart) {
u32 rotws, wmask;
rotws = (((newregs.windowstart |
(newregs.windowstart << WSBITS)) >>
newregs.windowbase) &
((1 << WSBITS) - 1)) & ~1;
wmask = ((rotws ? WSBITS + 1 - ffs(rotws) : 0) << 4) |
(rotws & 0xF) | 1;
regs->windowbase = newregs.windowbase;
regs->windowstart = newregs.windowstart;
regs->wmask = wmask;
}
memcpy(regs->areg + XCHAL_NUM_AREGS - newregs.windowbase * 4,
newregs.a, newregs.windowbase * 16);
memcpy(regs->areg, newregs.a + newregs.windowbase * 4,
(WSBITS - newregs.windowbase) * 16);
return 0;
}
static int tie_get(struct task_struct *target,
const struct user_regset *regset,
struct membuf to)
{
int ret;
struct pt_regs *regs = task_pt_regs(target);
struct thread_info *ti = task_thread_info(target);
elf_xtregs_t *newregs = kzalloc(sizeof(elf_xtregs_t), GFP_KERNEL);
if (!newregs)
return -ENOMEM;
newregs->opt = regs->xtregs_opt;
newregs->user = ti->xtregs_user;
#if XTENSA_HAVE_COPROCESSORS
/* Flush all coprocessor registers to memory. */
coprocessor_flush_all(ti);
newregs->cp0 = ti->xtregs_cp.cp0;
newregs->cp1 = ti->xtregs_cp.cp1;
newregs->cp2 = ti->xtregs_cp.cp2;
newregs->cp3 = ti->xtregs_cp.cp3;
newregs->cp4 = ti->xtregs_cp.cp4;
newregs->cp5 = ti->xtregs_cp.cp5;
newregs->cp6 = ti->xtregs_cp.cp6;
newregs->cp7 = ti->xtregs_cp.cp7;
#endif
ret = membuf_write(&to, newregs, sizeof(*newregs));
kfree(newregs);
return ret;
}
static int tie_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 *regs = task_pt_regs(target);
struct thread_info *ti = task_thread_info(target);
elf_xtregs_t *newregs = kzalloc(sizeof(elf_xtregs_t), GFP_KERNEL);
if (!newregs)
return -ENOMEM;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
newregs, 0, -1);
if (ret)
goto exit;
regs->xtregs_opt = newregs->opt;
ti->xtregs_user = newregs->user;
#if XTENSA_HAVE_COPROCESSORS
/* Flush all coprocessors before we overwrite them. */
coprocessor_flush_release_all(ti);
ti->xtregs_cp.cp0 = newregs->cp0;
ti->xtregs_cp.cp1 = newregs->cp1;
ti->xtregs_cp.cp2 = newregs->cp2;
ti->xtregs_cp.cp3 = newregs->cp3;
ti->xtregs_cp.cp4 = newregs->cp4;
ti->xtregs_cp.cp5 = newregs->cp5;
ti->xtregs_cp.cp6 = newregs->cp6;
ti->xtregs_cp.cp7 = newregs->cp7;
#endif
exit:
kfree(newregs);
return ret;
}
enum xtensa_regset {
REGSET_GPR,
REGSET_TIE,
};
static const struct user_regset xtensa_regsets[] = {
[REGSET_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = sizeof(struct user_pt_regs) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
.regset_get = gpr_get,
.set = gpr_set,
},
[REGSET_TIE] = {
.core_note_type = NT_PRFPREG,
.n = sizeof(elf_xtregs_t) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
.regset_get = tie_get,
.set = tie_set,
},
};
static const struct user_regset_view user_xtensa_view = {
.name = "xtensa",
.e_machine = EM_XTENSA,
.regsets = xtensa_regsets,
.n = ARRAY_SIZE(xtensa_regsets)
};
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
return &user_xtensa_view;
}
void user_enable_single_step(struct task_struct *child)
{
set_tsk_thread_flag(child, TIF_SINGLESTEP);
}
void user_disable_single_step(struct task_struct *child)
{
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
}
/*
* Called by kernel/ptrace.c when detaching to disable single stepping.
*/
void ptrace_disable(struct task_struct *child)
{
/* Nothing to do.. */
}
static int ptrace_getregs(struct task_struct *child, void __user *uregs)
{
return copy_regset_to_user(child, &user_xtensa_view, REGSET_GPR,
0, sizeof(xtensa_gregset_t), uregs);
}
static int ptrace_setregs(struct task_struct *child, void __user *uregs)
{
return copy_regset_from_user(child, &user_xtensa_view, REGSET_GPR,
0, sizeof(xtensa_gregset_t), uregs);
}
static int ptrace_getxregs(struct task_struct *child, void __user *uregs)
{
return copy_regset_to_user(child, &user_xtensa_view, REGSET_TIE,
0, sizeof(elf_xtregs_t), uregs);
}
static int ptrace_setxregs(struct task_struct *child, void __user *uregs)
{
return copy_regset_from_user(child, &user_xtensa_view, REGSET_TIE,
0, sizeof(elf_xtregs_t), uregs);
}
static int ptrace_peekusr(struct task_struct *child, long regno,
long __user *ret)
{
struct pt_regs *regs;
unsigned long tmp;
regs = task_pt_regs(child);
tmp = 0; /* Default return value. */
switch(regno) {
case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
tmp = regs->areg[regno - REG_AR_BASE];
break;
case REG_A_BASE ... REG_A_BASE + 15:
tmp = regs->areg[regno - REG_A_BASE];
break;
case REG_PC:
tmp = regs->pc;
break;
case REG_PS:
/* Note: PS.EXCM is not set while user task is running;
* its being set in regs is for exception handling
* convenience.
*/
tmp = (regs->ps & ~(1 << PS_EXCM_BIT));
break;
case REG_WB:
break; /* tmp = 0 */
case REG_WS:
{
unsigned long wb = regs->windowbase;
unsigned long ws = regs->windowstart;
tmp = ((ws >> wb) | (ws << (WSBITS - wb))) &
((1 << WSBITS) - 1);
break;
}
case REG_LBEG:
tmp = regs->lbeg;
break;
case REG_LEND:
tmp = regs->lend;
break;
case REG_LCOUNT:
tmp = regs->lcount;
break;
case REG_SAR:
tmp = regs->sar;
break;
case SYSCALL_NR:
tmp = regs->syscall;
break;
default:
return -EIO;
}
return put_user(tmp, ret);
}
static int ptrace_pokeusr(struct task_struct *child, long regno, long val)
{
struct pt_regs *regs;
regs = task_pt_regs(child);
switch (regno) {
case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
regs->areg[regno - REG_AR_BASE] = val;
break;
case REG_A_BASE ... REG_A_BASE + 15:
regs->areg[regno - REG_A_BASE] = val;
break;
case REG_PC:
regs->pc = val;
break;
case SYSCALL_NR:
regs->syscall = val;
break;
default:
return -EIO;
}
return 0;
}
#ifdef CONFIG_HAVE_HW_BREAKPOINT
static void ptrace_hbptriggered(struct perf_event *bp,
struct perf_sample_data *data,
struct pt_regs *regs)
{
int i;
struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
if (bp->attr.bp_type & HW_BREAKPOINT_X) {
for (i = 0; i < XCHAL_NUM_IBREAK; ++i)
if (current->thread.ptrace_bp[i] == bp)
break;
i <<= 1;
} else {
for (i = 0; i < XCHAL_NUM_DBREAK; ++i)
if (current->thread.ptrace_wp[i] == bp)
break;
i = (i << 1) | 1;
}
force_sig_ptrace_errno_trap(i, (void __user *)bkpt->address);
}
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 = 1;
attr.bp_type = type;
attr.disabled = 1;
return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
tsk);
}
/*
* Address bit 0 choose instruction (0) or data (1) break register, bits
* 31..1 are the register number.
* Both PTRACE_GETHBPREGS and PTRACE_SETHBPREGS transfer two 32-bit words:
* address (0) and control (1).
* Instruction breakpoint contorl word is 0 to clear breakpoint, 1 to set.
* Data breakpoint control word bit 31 is 'trigger on store', bit 30 is
* 'trigger on load, bits 29..0 are length. Length 0 is used to clear a
* breakpoint. To set a breakpoint length must be a power of 2 in the range
* 1..64 and the address must be length-aligned.
*/
static long ptrace_gethbpregs(struct task_struct *child, long addr,
long __user *datap)
{
struct perf_event *bp;
u32 user_data[2] = {0};
bool dbreak = addr & 1;
unsigned idx = addr >> 1;
if ((!dbreak && idx >= XCHAL_NUM_IBREAK) ||
(dbreak && idx >= XCHAL_NUM_DBREAK))
return -EINVAL;
if (dbreak)
bp = child->thread.ptrace_wp[idx];
else
bp = child->thread.ptrace_bp[idx];
if (bp) {
user_data[0] = bp->attr.bp_addr;
user_data[1] = bp->attr.disabled ? 0 : bp->attr.bp_len;
if (dbreak) {
if (bp->attr.bp_type & HW_BREAKPOINT_R)
user_data[1] |= DBREAKC_LOAD_MASK;
if (bp->attr.bp_type & HW_BREAKPOINT_W)
user_data[1] |= DBREAKC_STOR_MASK;
}
}
if (copy_to_user(datap, user_data, sizeof(user_data)))
return -EFAULT;
return 0;
}
static long ptrace_sethbpregs(struct task_struct *child, long addr,
long __user *datap)
{
struct perf_event *bp;
struct perf_event_attr attr;
u32 user_data[2];
bool dbreak = addr & 1;
unsigned idx = addr >> 1;
int bp_type = 0;
if ((!dbreak && idx >= XCHAL_NUM_IBREAK) ||
(dbreak && idx >= XCHAL_NUM_DBREAK))
return -EINVAL;
if (copy_from_user(user_data, datap, sizeof(user_data)))
return -EFAULT;
if (dbreak) {
bp = child->thread.ptrace_wp[idx];
if (user_data[1] & DBREAKC_LOAD_MASK)
bp_type |= HW_BREAKPOINT_R;
if (user_data[1] & DBREAKC_STOR_MASK)
bp_type |= HW_BREAKPOINT_W;
} else {
bp = child->thread.ptrace_bp[idx];
bp_type = HW_BREAKPOINT_X;
}
if (!bp) {
bp = ptrace_hbp_create(child,
bp_type ? bp_type : HW_BREAKPOINT_RW);
if (IS_ERR(bp))
return PTR_ERR(bp);
if (dbreak)
child->thread.ptrace_wp[idx] = bp;
else
child->thread.ptrace_bp[idx] = bp;
}
attr = bp->attr;
attr.bp_addr = user_data[0];
attr.bp_len = user_data[1] & ~(DBREAKC_LOAD_MASK | DBREAKC_STOR_MASK);
attr.bp_type = bp_type;
attr.disabled = !attr.bp_len;
return modify_user_hw_breakpoint(bp, &attr);
}
#endif
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
int ret = -EPERM;
void __user *datap = (void __user *) data;
switch (request) {
case PTRACE_PEEKUSR: /* read register specified by addr. */
ret = ptrace_peekusr(child, addr, datap);
break;
case PTRACE_POKEUSR: /* write register specified by addr. */
ret = ptrace_pokeusr(child, addr, data);
break;
case PTRACE_GETREGS:
ret = ptrace_getregs(child, datap);
break;
case PTRACE_SETREGS:
ret = ptrace_setregs(child, datap);
break;
case PTRACE_GETXTREGS:
ret = ptrace_getxregs(child, datap);
break;
case PTRACE_SETXTREGS:
ret = ptrace_setxregs(child, datap);
break;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
case PTRACE_GETHBPREGS:
ret = ptrace_gethbpregs(child, addr, datap);
break;
case PTRACE_SETHBPREGS:
ret = ptrace_sethbpregs(child, addr, datap);
break;
#endif
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
int do_syscall_trace_enter(struct pt_regs *regs)
{
if (regs->syscall == NO_SYSCALL)
regs->areg[2] = -ENOSYS;
if (test_thread_flag(TIF_SYSCALL_TRACE) &&
ptrace_report_syscall_entry(regs)) {
regs->areg[2] = -ENOSYS;
regs->syscall = NO_SYSCALL;
return 0;
}
if (regs->syscall == NO_SYSCALL ||
secure_computing() == -1) {
do_syscall_trace_leave(regs);
return 0;
}
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_enter(regs, syscall_get_nr(current, regs));
audit_syscall_entry(regs->syscall, regs->areg[6],
regs->areg[3], regs->areg[4],
regs->areg[5]);
return 1;
}
void do_syscall_trace_leave(struct pt_regs *regs)
{
int step;
audit_syscall_exit(regs);
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_exit(regs, regs_return_value(regs));
step = test_thread_flag(TIF_SINGLESTEP);
if (step || test_thread_flag(TIF_SYSCALL_TRACE))
ptrace_report_syscall_exit(regs, step);
}
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