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Diffstat (limited to 'arch/powerpc/kernel/ptrace/ptrace-noadv.c')
-rw-r--r--arch/powerpc/kernel/ptrace/ptrace-noadv.c298
1 files changed, 298 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
new file mode 100644
index 0000000000..a5dd7d2e2c
--- /dev/null
+++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/regset.h>
+#include <linux/hw_breakpoint.h>
+
+#include <asm/debug.h>
+
+#include "ptrace-decl.h"
+
+void user_enable_single_step(struct task_struct *task)
+{
+ struct pt_regs *regs = task->thread.regs;
+
+ if (regs != NULL)
+ regs_set_return_msr(regs, (regs->msr & ~MSR_BE) | MSR_SE);
+ 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)
+ regs_set_return_msr(regs, (regs->msr & ~MSR_SE) | MSR_BE);
+ 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)
+ regs_set_return_msr(regs, regs->msr & ~(MSR_SE | MSR_BE));
+
+ clear_tsk_thread_flag(task, TIF_SINGLESTEP);
+}
+
+void ppc_gethwdinfo(struct ppc_debug_info *dbginfo)
+{
+ dbginfo->version = 1;
+ dbginfo->num_instruction_bps = 0;
+ if (ppc_breakpoint_available())
+ dbginfo->num_data_bps = nr_wp_slots();
+ else
+ dbginfo->num_data_bps = 0;
+ dbginfo->num_condition_regs = 0;
+ dbginfo->data_bp_alignment = sizeof(long);
+ dbginfo->sizeof_condition = 0;
+ if (IS_ENABLED(CONFIG_HAVE_HW_BREAKPOINT)) {
+ dbginfo->features = PPC_DEBUG_FEATURE_DATA_BP_RANGE;
+ if (dawr_enabled())
+ dbginfo->features |= PPC_DEBUG_FEATURE_DATA_BP_DAWR;
+ } else {
+ dbginfo->features = 0;
+ }
+ if (cpu_has_feature(CPU_FTR_ARCH_31))
+ dbginfo->features |= PPC_DEBUG_FEATURE_DATA_BP_ARCH_31;
+}
+
+int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
+ unsigned long __user *datalp)
+{
+ unsigned long dabr_fake;
+
+ /* We only support one DABR and no IABRS at the moment */
+ if (addr > 0)
+ return -EINVAL;
+ dabr_fake = ((child->thread.hw_brk[0].address & (~HW_BRK_TYPE_DABR)) |
+ (child->thread.hw_brk[0].type & HW_BRK_TYPE_DABR));
+ return put_user(dabr_fake, datalp);
+}
+
+/*
+ * ptrace_set_debugreg() fakes DABR and DABR is only one. So even if
+ * internal hw supports more than one watchpoint, we support only one
+ * watchpoint with this interface.
+ */
+int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data)
+{
+#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 */
+ bool set_bp = true;
+ struct arch_hw_breakpoint hw_brk;
+
+ /* 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;
+
+ /* For processors using DABR (i.e. 970), the bottom 3 bits are flags.
+ * It was assumed, on previous implementations, that 3 bits were
+ * passed together with the data address, fitting the design of the
+ * DABR register, as follows:
+ *
+ * bit 0: Read flag
+ * bit 1: Write flag
+ * bit 2: Breakpoint translation
+ *
+ * Thus, we use them here as so.
+ */
+
+ /* Ensure breakpoint translation bit is set */
+ if (data && !(data & HW_BRK_TYPE_TRANSLATE))
+ return -EIO;
+ hw_brk.address = data & (~HW_BRK_TYPE_DABR);
+ hw_brk.type = (data & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
+ hw_brk.len = DABR_MAX_LEN;
+ hw_brk.hw_len = DABR_MAX_LEN;
+ set_bp = (data) && (hw_brk.type & HW_BRK_TYPE_RDWR);
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ bp = thread->ptrace_bps[0];
+ if (!set_bp) {
+ if (bp) {
+ unregister_hw_breakpoint(bp);
+ thread->ptrace_bps[0] = NULL;
+ }
+ return 0;
+ }
+ if (bp) {
+ attr = bp->attr;
+ attr.bp_addr = hw_brk.address;
+ attr.bp_len = DABR_MAX_LEN;
+ arch_bp_generic_fields(hw_brk.type, &attr.bp_type);
+
+ /* Enable breakpoint */
+ attr.disabled = false;
+
+ ret = modify_user_hw_breakpoint(bp, &attr);
+ if (ret)
+ return ret;
+
+ thread->ptrace_bps[0] = bp;
+ thread->hw_brk[0] = hw_brk;
+ return 0;
+ }
+
+ /* Create a new breakpoint request if one doesn't exist already */
+ hw_breakpoint_init(&attr);
+ attr.bp_addr = hw_brk.address;
+ attr.bp_len = DABR_MAX_LEN;
+ arch_bp_generic_fields(hw_brk.type,
+ &attr.bp_type);
+
+ thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr,
+ ptrace_triggered, NULL, task);
+ if (IS_ERR(bp)) {
+ thread->ptrace_bps[0] = NULL;
+ return PTR_ERR(bp);
+ }
+
+#else /* !CONFIG_HAVE_HW_BREAKPOINT */
+ if (set_bp && (!ppc_breakpoint_available()))
+ return -ENODEV;
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+ task->thread.hw_brk[0] = hw_brk;
+ return 0;
+}
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+static int find_empty_ptrace_bp(struct thread_struct *thread)
+{
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!thread->ptrace_bps[i])
+ return i;
+ }
+ return -1;
+}
+#endif
+
+static int find_empty_hw_brk(struct thread_struct *thread)
+{
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!thread->hw_brk[i].address)
+ return i;
+ }
+ return -1;
+}
+
+long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_info)
+{
+ int i;
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ int len = 0;
+ struct thread_struct *thread = &child->thread;
+ struct perf_event *bp;
+ struct perf_event_attr attr;
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+ struct arch_hw_breakpoint brk;
+
+ if (bp_info->version != 1)
+ return -ENOTSUPP;
+ /*
+ * We only support one data breakpoint
+ */
+ if ((bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_RW) == 0 ||
+ (bp_info->trigger_type & ~PPC_BREAKPOINT_TRIGGER_RW) != 0 ||
+ bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
+ return -EINVAL;
+
+ if ((unsigned long)bp_info->addr >= TASK_SIZE)
+ return -EIO;
+
+ brk.address = ALIGN_DOWN(bp_info->addr, HW_BREAKPOINT_SIZE);
+ brk.type = HW_BRK_TYPE_TRANSLATE | HW_BRK_TYPE_PRIV_ALL;
+ brk.len = DABR_MAX_LEN;
+ brk.hw_len = DABR_MAX_LEN;
+ if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
+ brk.type |= HW_BRK_TYPE_READ;
+ if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
+ brk.type |= HW_BRK_TYPE_WRITE;
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
+ len = bp_info->addr2 - bp_info->addr;
+ else if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
+ len = 1;
+ else
+ return -EINVAL;
+
+ i = find_empty_ptrace_bp(thread);
+ if (i < 0)
+ return -ENOSPC;
+
+ /* Create a new breakpoint request if one doesn't exist already */
+ hw_breakpoint_init(&attr);
+ attr.bp_addr = (unsigned long)bp_info->addr;
+ attr.bp_len = len;
+ arch_bp_generic_fields(brk.type, &attr.bp_type);
+
+ bp = register_user_hw_breakpoint(&attr, ptrace_triggered, NULL, child);
+ thread->ptrace_bps[i] = bp;
+ if (IS_ERR(bp)) {
+ thread->ptrace_bps[i] = NULL;
+ return PTR_ERR(bp);
+ }
+
+ return i + 1;
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+
+ if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
+ return -EINVAL;
+
+ i = find_empty_hw_brk(&child->thread);
+ if (i < 0)
+ return -ENOSPC;
+
+ if (!ppc_breakpoint_available())
+ return -ENODEV;
+
+ child->thread.hw_brk[i] = brk;
+
+ return i + 1;
+}
+
+long ppc_del_hwdebug(struct task_struct *child, long data)
+{
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ int ret = 0;
+ struct thread_struct *thread = &child->thread;
+ struct perf_event *bp;
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+ if (data < 1 || data > nr_wp_slots())
+ return -EINVAL;
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ bp = thread->ptrace_bps[data - 1];
+ if (bp) {
+ unregister_hw_breakpoint(bp);
+ thread->ptrace_bps[data - 1] = NULL;
+ } else {
+ ret = -ENOENT;
+ }
+ return ret;
+#else /* CONFIG_HAVE_HW_BREAKPOINT */
+ if (!(child->thread.hw_brk[data - 1].flags & HW_BRK_FLAG_DISABLED) &&
+ child->thread.hw_brk[data - 1].address == 0)
+ return -ENOENT;
+
+ child->thread.hw_brk[data - 1].address = 0;
+ child->thread.hw_brk[data - 1].type = 0;
+ child->thread.hw_brk[data - 1].flags = 0;
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+
+ return 0;
+}