diff options
Diffstat (limited to 'arch/powerpc/kernel/ptrace/ptrace-adv.c')
| -rw-r--r-- | arch/powerpc/kernel/ptrace/ptrace-adv.c | 494 |
1 files changed, 494 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/ptrace/ptrace-adv.c b/arch/powerpc/kernel/ptrace/ptrace-adv.c new file mode 100644 index 000000000000..399f5d94a3df --- /dev/null +++ b/arch/powerpc/kernel/ptrace/ptrace-adv.c @@ -0,0 +1,494 @@ +// 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; +} |