original_kernel/arch/powerpc/kernel/ptrace/ptrace-adv.c

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// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/regset.h>
#include <linux/hw_breakpoint.h>
#include "ptrace-decl.h"
void user_enable_single_step(struct task_struct *task)
{
struct pt_regs *regs = task->thread.regs;
if (regs != NULL) {
task->thread.debug.dbcr0 &= ~DBCR0_BT;
task->thread.debug.dbcr0 |= DBCR0_IDM | DBCR0_IC;
regs_set_return_msr(regs, regs->msr | MSR_DE);
}
set_tsk_thread_flag(task, TIF_SINGLESTEP);
}
void user_enable_block_step(struct task_struct *task)
{
struct pt_regs *regs = task->thread.regs;
if (regs != NULL) {
task->thread.debug.dbcr0 &= ~DBCR0_IC;
task->thread.debug.dbcr0 = DBCR0_IDM | DBCR0_BT;
regs_set_return_msr(regs, regs->msr | MSR_DE);
}
set_tsk_thread_flag(task, TIF_SINGLESTEP);
}
void user_disable_single_step(struct task_struct *task)
{
struct pt_regs *regs = task->thread.regs;
if (regs != NULL) {
/*
* The logic to disable single stepping should be as
* simple as turning off the Instruction Complete flag.
* And, after doing so, if all debug flags are off, turn
* off DBCR0(IDM) and MSR(DE) .... Torez
*/
task->thread.debug.dbcr0 &= ~(DBCR0_IC | DBCR0_BT);
/*
* Test to see if any of the DBCR_ACTIVE_EVENTS bits are set.
*/
if (!DBCR_ACTIVE_EVENTS(task->thread.debug.dbcr0,
task->thread.debug.dbcr1)) {
/*
* All debug events were off.....
*/
task->thread.debug.dbcr0 &= ~DBCR0_IDM;
regs_set_return_msr(regs, regs->msr & ~MSR_DE);
}
}
clear_tsk_thread_flag(task, TIF_SINGLESTEP);
}
void ppc_gethwdinfo(struct ppc_debug_info *dbginfo)
{
dbginfo->version = 1;
dbginfo->num_instruction_bps = CONFIG_PPC_ADV_DEBUG_IACS;
dbginfo->num_data_bps = CONFIG_PPC_ADV_DEBUG_DACS;
dbginfo->num_condition_regs = CONFIG_PPC_ADV_DEBUG_DVCS;
dbginfo->data_bp_alignment = 4;
dbginfo->sizeof_condition = 4;
dbginfo->features = PPC_DEBUG_FEATURE_INSN_BP_RANGE |
PPC_DEBUG_FEATURE_INSN_BP_MASK;
if (IS_ENABLED(CONFIG_PPC_ADV_DEBUG_DAC_RANGE))
dbginfo->features |= PPC_DEBUG_FEATURE_DATA_BP_RANGE |
PPC_DEBUG_FEATURE_DATA_BP_MASK;
}
int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
unsigned long __user *datalp)
{
/* We only support one DABR and no IABRS at the moment */
if (addr > 0)
return -EINVAL;
return put_user(child->thread.debug.dac1, datalp);
}
int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data)
{
struct pt_regs *regs = task->thread.regs;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
int ret;
struct thread_struct *thread = &task->thread;
struct perf_event *bp;
struct perf_event_attr attr;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
/* For ppc64 we support one DABR and no IABR's at the moment (ppc64).
* For embedded processors we support one DAC and no IAC's at the
* moment.
*/
if (addr > 0)
return -EINVAL;
/* The bottom 3 bits in dabr are flags */
if ((data & ~0x7UL) >= TASK_SIZE)
return -EIO;
/* As described above, it was assumed 3 bits were passed with the data
* address, but we will assume only the mode bits will be passed
* as to not cause alignment restrictions for DAC-based processors.
*/
/* DAC's hold the whole address without any mode flags */
task->thread.debug.dac1 = data & ~0x3UL;
if (task->thread.debug.dac1 == 0) {
dbcr_dac(task) &= ~(DBCR_DAC1R | DBCR_DAC1W);
if (!DBCR_ACTIVE_EVENTS(task->thread.debug.dbcr0,
task->thread.debug.dbcr1)) {
regs_set_return_msr(regs, regs->msr & ~MSR_DE);
task->thread.debug.dbcr0 &= ~DBCR0_IDM;
}
return 0;
}
/* Read or Write bits must be set */
if (!(data & 0x3UL))
return -EINVAL;
/* Set the Internal Debugging flag (IDM bit 1) for the DBCR0 register */
task->thread.debug.dbcr0 |= DBCR0_IDM;
/* Check for write and read flags and set DBCR0 accordingly */
dbcr_dac(task) &= ~(DBCR_DAC1R | DBCR_DAC1W);
if (data & 0x1UL)
dbcr_dac(task) |= DBCR_DAC1R;
if (data & 0x2UL)
dbcr_dac(task) |= DBCR_DAC1W;
regs_set_return_msr(regs, regs->msr | MSR_DE);
return 0;
}
static long set_instruction_bp(struct task_struct *child,
struct ppc_hw_breakpoint *bp_info)
{
int slot;
int slot1_in_use = ((child->thread.debug.dbcr0 & DBCR0_IAC1) != 0);
int slot2_in_use = ((child->thread.debug.dbcr0 & DBCR0_IAC2) != 0);
int slot3_in_use = ((child->thread.debug.dbcr0 & DBCR0_IAC3) != 0);
int slot4_in_use = ((child->thread.debug.dbcr0 & DBCR0_IAC4) != 0);
if (dbcr_iac_range(child) & DBCR_IAC12MODE)
slot2_in_use = 1;
if (dbcr_iac_range(child) & DBCR_IAC34MODE)
slot4_in_use = 1;
if (bp_info->addr >= TASK_SIZE)
return -EIO;
if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT) {
/* Make sure range is valid. */
if (bp_info->addr2 >= TASK_SIZE)
return -EIO;
/* We need a pair of IAC regsisters */
if (!slot1_in_use && !slot2_in_use) {
slot = 1;
child->thread.debug.iac1 = bp_info->addr;
child->thread.debug.iac2 = bp_info->addr2;
child->thread.debug.dbcr0 |= DBCR0_IAC1;
if (bp_info->addr_mode ==
PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
dbcr_iac_range(child) |= DBCR_IAC12X;
else
dbcr_iac_range(child) |= DBCR_IAC12I;
#if CONFIG_PPC_ADV_DEBUG_IACS > 2
} else if ((!slot3_in_use) && (!slot4_in_use)) {
slot = 3;
child->thread.debug.iac3 = bp_info->addr;
child->thread.debug.iac4 = bp_info->addr2;
child->thread.debug.dbcr0 |= DBCR0_IAC3;
if (bp_info->addr_mode ==
PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
dbcr_iac_range(child) |= DBCR_IAC34X;
else
dbcr_iac_range(child) |= DBCR_IAC34I;
#endif
} else {
return -ENOSPC;
}
} else {
/* We only need one. If possible leave a pair free in
* case a range is needed later
*/
if (!slot1_in_use) {
/*
* Don't use iac1 if iac1-iac2 are free and either
* iac3 or iac4 (but not both) are free
*/
if (slot2_in_use || slot3_in_use == slot4_in_use) {
slot = 1;
child->thread.debug.iac1 = bp_info->addr;
child->thread.debug.dbcr0 |= DBCR0_IAC1;
goto out;
}
}
if (!slot2_in_use) {
slot = 2;
child->thread.debug.iac2 = bp_info->addr;
child->thread.debug.dbcr0 |= DBCR0_IAC2;
#if CONFIG_PPC_ADV_DEBUG_IACS > 2
} else if (!slot3_in_use) {
slot = 3;
child->thread.debug.iac3 = bp_info->addr;
child->thread.debug.dbcr0 |= DBCR0_IAC3;
} else if (!slot4_in_use) {
slot = 4;
child->thread.debug.iac4 = bp_info->addr;
child->thread.debug.dbcr0 |= DBCR0_IAC4;
#endif
} else {
return -ENOSPC;
}
}
out:
child->thread.debug.dbcr0 |= DBCR0_IDM;
regs_set_return_msr(child->thread.regs, child->thread.regs->msr | MSR_DE);
return slot;
}
static int del_instruction_bp(struct task_struct *child, int slot)
{
switch (slot) {
case 1:
if ((child->thread.debug.dbcr0 & DBCR0_IAC1) == 0)
return -ENOENT;
if (dbcr_iac_range(child) & DBCR_IAC12MODE) {
/* address range - clear slots 1 & 2 */
child->thread.debug.iac2 = 0;
dbcr_iac_range(child) &= ~DBCR_IAC12MODE;
}
child->thread.debug.iac1 = 0;
child->thread.debug.dbcr0 &= ~DBCR0_IAC1;
break;
case 2:
if ((child->thread.debug.dbcr0 & DBCR0_IAC2) == 0)
return -ENOENT;
if (dbcr_iac_range(child) & DBCR_IAC12MODE)
/* used in a range */
return -EINVAL;
child->thread.debug.iac2 = 0;
child->thread.debug.dbcr0 &= ~DBCR0_IAC2;
break;
#if CONFIG_PPC_ADV_DEBUG_IACS > 2
case 3:
if ((child->thread.debug.dbcr0 & DBCR0_IAC3) == 0)
return -ENOENT;
if (dbcr_iac_range(child) & DBCR_IAC34MODE) {
/* address range - clear slots 3 & 4 */
child->thread.debug.iac4 = 0;
dbcr_iac_range(child) &= ~DBCR_IAC34MODE;
}
child->thread.debug.iac3 = 0;
child->thread.debug.dbcr0 &= ~DBCR0_IAC3;
break;
case 4:
if ((child->thread.debug.dbcr0 & DBCR0_IAC4) == 0)
return -ENOENT;
if (dbcr_iac_range(child) & DBCR_IAC34MODE)
/* Used in a range */
return -EINVAL;
child->thread.debug.iac4 = 0;
child->thread.debug.dbcr0 &= ~DBCR0_IAC4;
break;
#endif
default:
return -EINVAL;
}
return 0;
}
static int set_dac(struct task_struct *child, struct ppc_hw_breakpoint *bp_info)
{
int byte_enable =
(bp_info->condition_mode >> PPC_BREAKPOINT_CONDITION_BE_SHIFT)
& 0xf;
int condition_mode =
bp_info->condition_mode & PPC_BREAKPOINT_CONDITION_MODE;
int slot;
if (byte_enable && condition_mode == 0)
return -EINVAL;
if (bp_info->addr >= TASK_SIZE)
return -EIO;
if ((dbcr_dac(child) & (DBCR_DAC1R | DBCR_DAC1W)) == 0) {
slot = 1;
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
dbcr_dac(child) |= DBCR_DAC1R;
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
dbcr_dac(child) |= DBCR_DAC1W;
child->thread.debug.dac1 = (unsigned long)bp_info->addr;
#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
if (byte_enable) {
child->thread.debug.dvc1 =
(unsigned long)bp_info->condition_value;
child->thread.debug.dbcr2 |=
((byte_enable << DBCR2_DVC1BE_SHIFT) |
(condition_mode << DBCR2_DVC1M_SHIFT));
}
#endif
#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
} else if (child->thread.debug.dbcr2 & DBCR2_DAC12MODE) {
/* Both dac1 and dac2 are part of a range */
return -ENOSPC;
#endif
} else if ((dbcr_dac(child) & (DBCR_DAC2R | DBCR_DAC2W)) == 0) {
slot = 2;
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
dbcr_dac(child) |= DBCR_DAC2R;
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
dbcr_dac(child) |= DBCR_DAC2W;
child->thread.debug.dac2 = (unsigned long)bp_info->addr;
#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
if (byte_enable) {
child->thread.debug.dvc2 =
(unsigned long)bp_info->condition_value;
child->thread.debug.dbcr2 |=
((byte_enable << DBCR2_DVC2BE_SHIFT) |
(condition_mode << DBCR2_DVC2M_SHIFT));
}
#endif
} else {
return -ENOSPC;
}
child->thread.debug.dbcr0 |= DBCR0_IDM;
regs_set_return_msr(child->thread.regs, child->thread.regs->msr | MSR_DE);
return slot + 4;
}
static int del_dac(struct task_struct *child, int slot)
{
if (slot == 1) {
if ((dbcr_dac(child) & (DBCR_DAC1R | DBCR_DAC1W)) == 0)
return -ENOENT;
child->thread.debug.dac1 = 0;
dbcr_dac(child) &= ~(DBCR_DAC1R | DBCR_DAC1W);
#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
if (child->thread.debug.dbcr2 & DBCR2_DAC12MODE) {
child->thread.debug.dac2 = 0;
child->thread.debug.dbcr2 &= ~DBCR2_DAC12MODE;
}
child->thread.debug.dbcr2 &= ~(DBCR2_DVC1M | DBCR2_DVC1BE);
#endif
#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
child->thread.debug.dvc1 = 0;
#endif
} else if (slot == 2) {
if ((dbcr_dac(child) & (DBCR_DAC2R | DBCR_DAC2W)) == 0)
return -ENOENT;
#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
if (child->thread.debug.dbcr2 & DBCR2_DAC12MODE)
/* Part of a range */
return -EINVAL;
child->thread.debug.dbcr2 &= ~(DBCR2_DVC2M | DBCR2_DVC2BE);
#endif
#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
child->thread.debug.dvc2 = 0;
#endif
child->thread.debug.dac2 = 0;
dbcr_dac(child) &= ~(DBCR_DAC2R | DBCR_DAC2W);
} else {
return -EINVAL;
}
return 0;
}
#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
static int set_dac_range(struct task_struct *child,
struct ppc_hw_breakpoint *bp_info)
{
int mode = bp_info->addr_mode & PPC_BREAKPOINT_MODE_MASK;
/* We don't allow range watchpoints to be used with DVC */
if (bp_info->condition_mode)
return -EINVAL;
/*
* Best effort to verify the address range. The user/supervisor bits
* prevent trapping in kernel space, but let's fail on an obvious bad
* range. The simple test on the mask is not fool-proof, and any
* exclusive range will spill over into kernel space.
*/
if (bp_info->addr >= TASK_SIZE)
return -EIO;
if (mode == PPC_BREAKPOINT_MODE_MASK) {
/*
* dac2 is a bitmask. Don't allow a mask that makes a
* kernel space address from a valid dac1 value
*/
if (~((unsigned long)bp_info->addr2) >= TASK_SIZE)
return -EIO;
} else {
/*
* For range breakpoints, addr2 must also be a valid address
*/
if (bp_info->addr2 >= TASK_SIZE)
return -EIO;
}
if (child->thread.debug.dbcr0 &
(DBCR0_DAC1R | DBCR0_DAC1W | DBCR0_DAC2R | DBCR0_DAC2W))
return -ENOSPC;
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
child->thread.debug.dbcr0 |= (DBCR0_DAC1R | DBCR0_IDM);
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
child->thread.debug.dbcr0 |= (DBCR0_DAC1W | DBCR0_IDM);
child->thread.debug.dac1 = bp_info->addr;
child->thread.debug.dac2 = bp_info->addr2;
if (mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
child->thread.debug.dbcr2 |= DBCR2_DAC12M;
else if (mode == PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
child->thread.debug.dbcr2 |= DBCR2_DAC12MX;
else /* PPC_BREAKPOINT_MODE_MASK */
child->thread.debug.dbcr2 |= DBCR2_DAC12MM;
regs_set_return_msr(child->thread.regs, child->thread.regs->msr | MSR_DE);
return 5;
}
#endif /* CONFIG_PPC_ADV_DEBUG_DAC_RANGE */
long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_info)
{
if (bp_info->version != 1)
return -ENOTSUPP;
/*
* Check for invalid flags and combinations
*/
if (bp_info->trigger_type == 0 ||
(bp_info->trigger_type & ~(PPC_BREAKPOINT_TRIGGER_EXECUTE |
PPC_BREAKPOINT_TRIGGER_RW)) ||
(bp_info->addr_mode & ~PPC_BREAKPOINT_MODE_MASK) ||
(bp_info->condition_mode &
~(PPC_BREAKPOINT_CONDITION_MODE |
PPC_BREAKPOINT_CONDITION_BE_ALL)))
return -EINVAL;
#if CONFIG_PPC_ADV_DEBUG_DVCS == 0
if (bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
return -EINVAL;
#endif
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_EXECUTE) {
if (bp_info->trigger_type != PPC_BREAKPOINT_TRIGGER_EXECUTE ||
bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
return -EINVAL;
return set_instruction_bp(child, bp_info);
}
if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
return set_dac(child, bp_info);
#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
return set_dac_range(child, bp_info);
#else
return -EINVAL;
#endif
}
long ppc_del_hwdebug(struct task_struct *child, long data)
{
int rc;
if (data <= 4)
rc = del_instruction_bp(child, (int)data);
else
rc = del_dac(child, (int)data - 4);
if (!rc) {
if (!DBCR_ACTIVE_EVENTS(child->thread.debug.dbcr0,
child->thread.debug.dbcr1)) {
child->thread.debug.dbcr0 &= ~DBCR0_IDM;
regs_set_return_msr(child->thread.regs,
child->thread.regs->msr & ~MSR_DE);
}
}
return rc;
}