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-rw-r--r--arch/powerpc/kernel/ptrace/ptrace-adv.c494
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 000000000..399f5d94a
--- /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;
+}