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-rw-r--r--arch/xtensa/kernel/Makefile2
-rw-r--r--arch/xtensa/kernel/asm-offsets.c12
-rw-r--r--arch/xtensa/kernel/entry.S90
-rw-r--r--arch/xtensa/kernel/head.S5
-rw-r--r--arch/xtensa/kernel/hw_breakpoint.c317
-rw-r--r--arch/xtensa/kernel/process.c5
-rw-r--r--arch/xtensa/kernel/ptrace.c164
-rw-r--r--arch/xtensa/kernel/smp.c2
-rw-r--r--arch/xtensa/kernel/traps.c69
-rw-r--r--arch/xtensa/kernel/vectors.S4
10 files changed, 626 insertions, 44 deletions
diff --git a/arch/xtensa/kernel/Makefile b/arch/xtensa/kernel/Makefile
index 4db730290..c31f5d5af 100644
--- a/arch/xtensa/kernel/Makefile
+++ b/arch/xtensa/kernel/Makefile
@@ -8,12 +8,12 @@ obj-y := align.o coprocessor.o entry.o irq.o pci-dma.o platform.o process.o \
ptrace.o setup.o signal.o stacktrace.o syscall.o time.o traps.o \
vectors.o
-obj-$(CONFIG_KGDB) += xtensa-stub.o
obj-$(CONFIG_PCI) += pci.o
obj-$(CONFIG_MODULES) += xtensa_ksyms.o module.o
obj-$(CONFIG_FUNCTION_TRACER) += mcount.o
obj-$(CONFIG_SMP) += smp.o mxhead.o
obj-$(CONFIG_XTENSA_VARIANT_HAVE_PERF_EVENTS) += perf_event.o
+obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
AFLAGS_head.o += -mtext-section-literals
AFLAGS_mxhead.o += -mtext-section-literals
diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c
index b123ace3b..8e10e357e 100644
--- a/arch/xtensa/kernel/asm-offsets.c
+++ b/arch/xtensa/kernel/asm-offsets.c
@@ -23,6 +23,7 @@
#include <linux/kbuild.h>
#include <asm/ptrace.h>
+#include <asm/traps.h>
#include <asm/uaccess.h>
int main(void)
@@ -117,5 +118,16 @@ int main(void)
DEFINE(_CLONE_UNTRACED, CLONE_UNTRACED);
DEFINE(PG_ARCH_1, PG_arch_1);
+ /* struct debug_table */
+ DEFINE(DT_DEBUG_EXCEPTION,
+ offsetof(struct debug_table, debug_exception));
+ DEFINE(DT_DEBUG_SAVE, offsetof(struct debug_table, debug_save));
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ DEFINE(DT_DBREAKC_SAVE, offsetof(struct debug_table, dbreakc_save));
+ DEFINE(DT_ICOUNT_SAVE, offsetof(struct debug_table, icount_save));
+ DEFINE(DT_ICOUNT_LEVEL_SAVE,
+ offsetof(struct debug_table, icount_level_save));
+#endif
+
return 0;
}
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index db5c1765b..fe8f7e7ef 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -543,6 +543,12 @@ common_exception_return:
#endif
5:
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ _bbci.l a4, TIF_DB_DISABLED, 7f
+ movi a4, restore_dbreak
+ callx4 a4
+7:
+#endif
#ifdef CONFIG_DEBUG_TLB_SANITY
l32i a4, a1, PT_DEPC
bgeui a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 4f
@@ -789,39 +795,99 @@ ENTRY(debug_exception)
movi a2, 1 << PS_EXCM_BIT
or a2, a0, a2
- movi a0, debug_exception # restore a3, debug jump vector
wsr a2, ps
- xsr a0, SREG_EXCSAVE + XCHAL_DEBUGLEVEL
/* Switch to kernel/user stack, restore jump vector, and save a0 */
bbsi.l a2, PS_UM_BIT, 2f # jump if user mode
addi a2, a1, -16-PT_SIZE # assume kernel stack
+3:
+ l32i a0, a3, DT_DEBUG_SAVE
+ s32i a1, a2, PT_AREG1
s32i a0, a2, PT_AREG0
movi a0, 0
- s32i a1, a2, PT_AREG1
s32i a0, a2, PT_DEPC # mark it as a regular exception
+ xsr a3, SREG_EXCSAVE + XCHAL_DEBUGLEVEL
xsr a0, depc
s32i a3, a2, PT_AREG3
s32i a0, a2, PT_AREG2
mov a1, a2
+
+ /* Debug exception is handled as an exception, so interrupts will
+ * likely be enabled in the common exception handler. Disable
+ * preemption if we have HW breakpoints to preserve DEBUGCAUSE.DBNUM
+ * meaning.
+ */
+#if defined(CONFIG_PREEMPT_COUNT) && defined(CONFIG_HAVE_HW_BREAKPOINT)
+ GET_THREAD_INFO(a2, a1)
+ l32i a3, a2, TI_PRE_COUNT
+ addi a3, a3, 1
+ s32i a3, a2, TI_PRE_COUNT
+#endif
+
+ rsr a2, ps
+ bbsi.l a2, PS_UM_BIT, _user_exception
j _kernel_exception
2: rsr a2, excsave1
l32i a2, a2, EXC_TABLE_KSTK # load kernel stack pointer
- s32i a0, a2, PT_AREG0
+ j 3b
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ /* Debug exception while in exception mode. This may happen when
+ * window overflow/underflow handler or fast exception handler hits
+ * data breakpoint, in which case save and disable all data
+ * breakpoints, single-step faulting instruction and restore data
+ * breakpoints.
+ */
+1:
+ bbci.l a0, PS_UM_BIT, 1b # jump if kernel mode
+
+ rsr a0, debugcause
+ bbsi.l a0, DEBUGCAUSE_DBREAK_BIT, .Ldebug_save_dbreak
+
+ .set _index, 0
+ .rept XCHAL_NUM_DBREAK
+ l32i a0, a3, DT_DBREAKC_SAVE + _index * 4
+ wsr a0, SREG_DBREAKC + _index
+ .set _index, _index + 1
+ .endr
+
+ l32i a0, a3, DT_ICOUNT_LEVEL_SAVE
+ wsr a0, icountlevel
+
+ l32i a0, a3, DT_ICOUNT_SAVE
+ xsr a0, icount
+
+ l32i a0, a3, DT_DEBUG_SAVE
+ xsr a3, SREG_EXCSAVE + XCHAL_DEBUGLEVEL
+ rfi XCHAL_DEBUGLEVEL
+
+.Ldebug_save_dbreak:
+ .set _index, 0
+ .rept XCHAL_NUM_DBREAK
movi a0, 0
- s32i a1, a2, PT_AREG1
- s32i a0, a2, PT_DEPC
- xsr a0, depc
- s32i a3, a2, PT_AREG3
- s32i a0, a2, PT_AREG2
- mov a1, a2
- j _user_exception
+ xsr a0, SREG_DBREAKC + _index
+ s32i a0, a3, DT_DBREAKC_SAVE + _index * 4
+ .set _index, _index + 1
+ .endr
- /* Debug exception while in exception mode. */
+ movi a0, XCHAL_EXCM_LEVEL + 1
+ xsr a0, icountlevel
+ s32i a0, a3, DT_ICOUNT_LEVEL_SAVE
+
+ movi a0, 0xfffffffe
+ xsr a0, icount
+ s32i a0, a3, DT_ICOUNT_SAVE
+
+ l32i a0, a3, DT_DEBUG_SAVE
+ xsr a3, SREG_EXCSAVE + XCHAL_DEBUGLEVEL
+ rfi XCHAL_DEBUGLEVEL
+#else
+ /* Debug exception while in exception mode. Should not happen. */
1: j 1b // FIXME!!
+#endif
ENDPROC(debug_exception)
diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S
index 05e1df943..bc4f4bf05 100644
--- a/arch/xtensa/kernel/head.S
+++ b/arch/xtensa/kernel/head.S
@@ -197,11 +197,6 @@ ENTRY(_startup)
wsr a2, ps # (enable reg-windows; progmode stack)
rsync
- /* Set up EXCSAVE[DEBUGLEVEL] to point to the Debug Exception Handler.*/
-
- movi a2, debug_exception
- wsr a2, SREG_EXCSAVE + XCHAL_DEBUGLEVEL
-
#ifdef CONFIG_SMP
/*
* Notice that we assume with SMP that cores have PRID
diff --git a/arch/xtensa/kernel/hw_breakpoint.c b/arch/xtensa/kernel/hw_breakpoint.c
new file mode 100644
index 000000000..b35656ab7
--- /dev/null
+++ b/arch/xtensa/kernel/hw_breakpoint.c
@@ -0,0 +1,317 @@
+/*
+ * Xtensa hardware breakpoints/watchpoints handling functions
+ *
+ * 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) 2016 Cadence Design Systems Inc.
+ */
+
+#include <linux/hw_breakpoint.h>
+#include <linux/log2.h>
+#include <linux/percpu.h>
+#include <linux/perf_event.h>
+#include <variant/core.h>
+
+/* Breakpoint currently in use for each IBREAKA. */
+static DEFINE_PER_CPU(struct perf_event *, bp_on_reg[XCHAL_NUM_IBREAK]);
+
+/* Watchpoint currently in use for each DBREAKA. */
+static DEFINE_PER_CPU(struct perf_event *, wp_on_reg[XCHAL_NUM_DBREAK]);
+
+int hw_breakpoint_slots(int type)
+{
+ switch (type) {
+ case TYPE_INST:
+ return XCHAL_NUM_IBREAK;
+ case TYPE_DATA:
+ return XCHAL_NUM_DBREAK;
+ default:
+ pr_warn("unknown slot type: %d\n", type);
+ return 0;
+ }
+}
+
+int arch_check_bp_in_kernelspace(struct perf_event *bp)
+{
+ unsigned int len;
+ unsigned long va;
+ struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+
+ va = info->address;
+ len = bp->attr.bp_len;
+
+ return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
+}
+
+/*
+ * Construct an arch_hw_breakpoint from a perf_event.
+ */
+static int arch_build_bp_info(struct perf_event *bp)
+{
+ struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+
+ /* Type */
+ switch (bp->attr.bp_type) {
+ case HW_BREAKPOINT_X:
+ info->type = XTENSA_BREAKPOINT_EXECUTE;
+ break;
+ case HW_BREAKPOINT_R:
+ info->type = XTENSA_BREAKPOINT_LOAD;
+ break;
+ case HW_BREAKPOINT_W:
+ info->type = XTENSA_BREAKPOINT_STORE;
+ break;
+ case HW_BREAKPOINT_RW:
+ info->type = XTENSA_BREAKPOINT_LOAD | XTENSA_BREAKPOINT_STORE;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Len */
+ info->len = bp->attr.bp_len;
+ if (info->len < 1 || info->len > 64 || !is_power_of_2(info->len))
+ return -EINVAL;
+
+ /* Address */
+ info->address = bp->attr.bp_addr;
+ if (info->address & (info->len - 1))
+ return -EINVAL;
+
+ return 0;
+}
+
+int arch_validate_hwbkpt_settings(struct perf_event *bp)
+{
+ int ret;
+
+ /* Build the arch_hw_breakpoint. */
+ ret = arch_build_bp_info(bp);
+ return ret;
+}
+
+int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
+ unsigned long val, void *data)
+{
+ return NOTIFY_DONE;
+}
+
+static void xtensa_wsr(unsigned long v, u8 sr)
+{
+ /* We don't have indexed wsr and creating instruction dynamically
+ * doesn't seem worth it given how small XCHAL_NUM_IBREAK and
+ * XCHAL_NUM_DBREAK are. Thus the switch. In case build breaks here
+ * the switch below needs to be extended.
+ */
+ BUILD_BUG_ON(XCHAL_NUM_IBREAK > 2);
+ BUILD_BUG_ON(XCHAL_NUM_DBREAK > 2);
+
+ switch (sr) {
+#if XCHAL_NUM_IBREAK > 0
+ case SREG_IBREAKA + 0:
+ WSR(v, SREG_IBREAKA + 0);
+ break;
+#endif
+#if XCHAL_NUM_IBREAK > 1
+ case SREG_IBREAKA + 1:
+ WSR(v, SREG_IBREAKA + 1);
+ break;
+#endif
+
+#if XCHAL_NUM_DBREAK > 0
+ case SREG_DBREAKA + 0:
+ WSR(v, SREG_DBREAKA + 0);
+ break;
+ case SREG_DBREAKC + 0:
+ WSR(v, SREG_DBREAKC + 0);
+ break;
+#endif
+#if XCHAL_NUM_DBREAK > 1
+ case SREG_DBREAKA + 1:
+ WSR(v, SREG_DBREAKA + 1);
+ break;
+
+ case SREG_DBREAKC + 1:
+ WSR(v, SREG_DBREAKC + 1);
+ break;
+#endif
+ }
+}
+
+static int alloc_slot(struct perf_event **slot, size_t n,
+ struct perf_event *bp)
+{
+ size_t i;
+
+ for (i = 0; i < n; ++i) {
+ if (!slot[i]) {
+ slot[i] = bp;
+ return i;
+ }
+ }
+ return -EBUSY;
+}
+
+static void set_ibreak_regs(int reg, struct perf_event *bp)
+{
+ struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+ unsigned long ibreakenable;
+
+ xtensa_wsr(info->address, SREG_IBREAKA + reg);
+ RSR(ibreakenable, SREG_IBREAKENABLE);
+ WSR(ibreakenable | (1 << reg), SREG_IBREAKENABLE);
+}
+
+static void set_dbreak_regs(int reg, struct perf_event *bp)
+{
+ struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+ unsigned long dbreakc = DBREAKC_MASK_MASK & -info->len;
+
+ if (info->type & XTENSA_BREAKPOINT_LOAD)
+ dbreakc |= DBREAKC_LOAD_MASK;
+ if (info->type & XTENSA_BREAKPOINT_STORE)
+ dbreakc |= DBREAKC_STOR_MASK;
+
+ xtensa_wsr(info->address, SREG_DBREAKA + reg);
+ xtensa_wsr(dbreakc, SREG_DBREAKC + reg);
+}
+
+int arch_install_hw_breakpoint(struct perf_event *bp)
+{
+ int i;
+
+ if (counter_arch_bp(bp)->type == XTENSA_BREAKPOINT_EXECUTE) {
+ /* Breakpoint */
+ i = alloc_slot(this_cpu_ptr(bp_on_reg), XCHAL_NUM_IBREAK, bp);
+ if (i < 0)
+ return i;
+ set_ibreak_regs(i, bp);
+
+ } else {
+ /* Watchpoint */
+ i = alloc_slot(this_cpu_ptr(wp_on_reg), XCHAL_NUM_DBREAK, bp);
+ if (i < 0)
+ return i;
+ set_dbreak_regs(i, bp);
+ }
+ return 0;
+}
+
+static int free_slot(struct perf_event **slot, size_t n,
+ struct perf_event *bp)
+{
+ size_t i;
+
+ for (i = 0; i < n; ++i) {
+ if (slot[i] == bp) {
+ slot[i] = NULL;
+ return i;
+ }
+ }
+ return -EBUSY;
+}
+
+void arch_uninstall_hw_breakpoint(struct perf_event *bp)
+{
+ struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+ int i;
+
+ if (info->type == XTENSA_BREAKPOINT_EXECUTE) {
+ unsigned long ibreakenable;
+
+ /* Breakpoint */
+ i = free_slot(this_cpu_ptr(bp_on_reg), XCHAL_NUM_IBREAK, bp);
+ if (i >= 0) {
+ RSR(ibreakenable, SREG_IBREAKENABLE);
+ WSR(ibreakenable & ~(1 << i), SREG_IBREAKENABLE);
+ }
+ } else {
+ /* Watchpoint */
+ i = free_slot(this_cpu_ptr(wp_on_reg), XCHAL_NUM_DBREAK, bp);
+ if (i >= 0)
+ xtensa_wsr(0, SREG_DBREAKC + i);
+ }
+}
+
+void hw_breakpoint_pmu_read(struct perf_event *bp)
+{
+}
+
+void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
+{
+ int i;
+ struct thread_struct *t = &tsk->thread;
+
+ for (i = 0; i < XCHAL_NUM_IBREAK; ++i) {
+ if (t->ptrace_bp[i]) {
+ unregister_hw_breakpoint(t->ptrace_bp[i]);
+ t->ptrace_bp[i] = NULL;
+ }
+ }
+ for (i = 0; i < XCHAL_NUM_DBREAK; ++i) {
+ if (t->ptrace_wp[i]) {
+ unregister_hw_breakpoint(t->ptrace_wp[i]);
+ t->ptrace_wp[i] = NULL;
+ }
+ }
+}
+
+/*
+ * Set ptrace breakpoint pointers to zero for this task.
+ * This is required in order to prevent child processes from unregistering
+ * breakpoints held by their parent.
+ */
+void clear_ptrace_hw_breakpoint(struct task_struct *tsk)
+{
+ memset(tsk->thread.ptrace_bp, 0, sizeof(tsk->thread.ptrace_bp));
+ memset(tsk->thread.ptrace_wp, 0, sizeof(tsk->thread.ptrace_wp));
+}
+
+void restore_dbreak(void)
+{
+ int i;
+
+ for (i = 0; i < XCHAL_NUM_DBREAK; ++i) {
+ struct perf_event *bp = this_cpu_ptr(wp_on_reg)[i];
+
+ if (bp)
+ set_dbreak_regs(i, bp);
+ }
+ clear_thread_flag(TIF_DB_DISABLED);
+}
+
+int check_hw_breakpoint(struct pt_regs *regs)
+{
+ if (regs->debugcause & BIT(DEBUGCAUSE_IBREAK_BIT)) {
+ int i;
+ struct perf_event **bp = this_cpu_ptr(bp_on_reg);
+
+ for (i = 0; i < XCHAL_NUM_IBREAK; ++i) {
+ if (bp[i] && !bp[i]->attr.disabled &&
+ regs->pc == bp[i]->attr.bp_addr)
+ perf_bp_event(bp[i], regs);
+ }
+ return 0;
+ } else if (regs->debugcause & BIT(DEBUGCAUSE_DBREAK_BIT)) {
+ struct perf_event **bp = this_cpu_ptr(wp_on_reg);
+ int dbnum = (regs->debugcause & DEBUGCAUSE_DBNUM_MASK) >>
+ DEBUGCAUSE_DBNUM_SHIFT;
+
+ if (dbnum < XCHAL_NUM_DBREAK && bp[dbnum]) {
+ if (user_mode(regs)) {
+ perf_bp_event(bp[dbnum], regs);
+ } else {
+ set_thread_flag(TIF_DB_DISABLED);
+ xtensa_wsr(0, SREG_DBREAKC + dbnum);
+ }
+ } else {
+ WARN_ONCE(1,
+ "Wrong/unconfigured DBNUM reported in DEBUGCAUSE: %d\n",
+ dbnum);
+ }
+ return 0;
+ }
+ return -ENOENT;
+}
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index 1c85323f0..5bbfed81c 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -24,6 +24,7 @@
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/elf.h>
+#include <linux/hw_breakpoint.h>
#include <linux/init.h>
#include <linux/prctl.h>
#include <linux/init_task.h>
@@ -43,6 +44,7 @@
#include <linux/atomic.h>
#include <asm/asm-offsets.h>
#include <asm/regs.h>
+#include <asm/hw_breakpoint.h>
extern void ret_from_fork(void);
extern void ret_from_kernel_thread(void);
@@ -131,6 +133,7 @@ void flush_thread(void)
coprocessor_flush_all(ti);
coprocessor_release_all(ti);
#endif
+ flush_ptrace_hw_breakpoint(current);
}
/*
@@ -273,6 +276,8 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
ti->cpenable = 0;
#endif
+ clear_ptrace_hw_breakpoint(p);
+
return 0;
}
diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
index 4d54b4811..a651f3a62 100644
--- a/arch/xtensa/kernel/ptrace.c
+++ b/arch/xtensa/kernel/ptrace.c
@@ -13,21 +13,23 @@
* Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca>
*/
+#include <linux/errno.h>
+#include <linux/hw_breakpoint.h>
#include <linux/kernel.h>
-#include <linux/sched.h>
#include <linux/mm.h>
-#include <linux/errno.h>
+#include <linux/perf_event.h>
#include <linux/ptrace.h>
-#include <linux/smp.h>
+#include <linux/sched.h>
#include <linux/security.h>
#include <linux/signal.h>
+#include <linux/smp.h>
-#include <asm/pgtable.h>
+#include <asm/coprocessor.h>
+#include <asm/elf.h>
#include <asm/page.h>
-#include <asm/uaccess.h>
+#include <asm/pgtable.h>
#include <asm/ptrace.h>
-#include <asm/elf.h>
-#include <asm/coprocessor.h>
+#include <asm/uaccess.h>
void user_enable_single_step(struct task_struct *child)
@@ -267,6 +269,146 @@ int ptrace_pokeusr(struct task_struct *child, long regno, long val)
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;
+ siginfo_t info;
+ 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;
+ }
+
+ info.si_signo = SIGTRAP;
+ info.si_errno = i;
+ info.si_code = TRAP_HWBKPT;
+ info.si_addr = (void __user *)bkpt->address;
+
+ force_sig_info(SIGTRAP, &info, current);
+}
+
+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)
{
@@ -307,7 +449,15 @@ long arch_ptrace(struct task_struct *child, long request,
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;
diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c
index 4d02e3851..fc4ad21a5 100644
--- a/arch/xtensa/kernel/smp.c
+++ b/arch/xtensa/kernel/smp.c
@@ -157,7 +157,7 @@ void secondary_start_kernel(void)
complete(&cpu_running);
- cpu_startup_entry(CPUHP_ONLINE);
+ cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
}
static void mx_cpu_start(void *p)
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index 42d441f78..d02fc304b 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -39,11 +39,7 @@
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/traps.h>
-
-#ifdef CONFIG_KGDB
-extern int gdb_enter;
-extern int return_from_debug_flag;
-#endif
+#include <asm/hw_breakpoint.h>
/*
* Machine specific interrupt handlers
@@ -162,6 +158,8 @@ COPROCESSOR(7),
DEFINE_PER_CPU(unsigned long, exc_table[EXC_TABLE_SIZE/4]);
+DEFINE_PER_CPU(struct debug_table, debug_table);
+
void die(const char*, struct pt_regs*, long);
static inline void
@@ -205,6 +203,32 @@ extern void do_IRQ(int, struct pt_regs *);
#if XTENSA_FAKE_NMI
+#define IS_POW2(v) (((v) & ((v) - 1)) == 0)
+
+#if !(PROFILING_INTLEVEL == XCHAL_EXCM_LEVEL && \
+ IS_POW2(XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL)))
+#warning "Fake NMI is requested for PMM, but there are other IRQs at or above its level."
+#warning "Fake NMI will be used, but there will be a bugcheck if one of those IRQs fire."
+
+static inline void check_valid_nmi(void)
+{
+ unsigned intread = get_sr(interrupt);
+ unsigned intenable = get_sr(intenable);
+
+ BUG_ON(intread & intenable &
+ ~(XTENSA_INTLEVEL_ANDBELOW_MASK(PROFILING_INTLEVEL) ^
+ XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL) ^
+ BIT(XCHAL_PROFILING_INTERRUPT)));
+}
+
+#else
+
+static inline void check_valid_nmi(void)
+{
+}
+
+#endif
+
irqreturn_t xtensa_pmu_irq_handler(int irq, void *dev_id);
DEFINE_PER_CPU(unsigned long, nmi_count);
@@ -219,6 +243,7 @@ void do_nmi(struct pt_regs *regs)
old_regs = set_irq_regs(regs);
nmi_enter();
++*this_cpu_ptr(&nmi_count);
+ check_valid_nmi();
xtensa_pmu_irq_handler(0, NULL);
nmi_exit();
set_irq_regs(old_regs);
@@ -314,23 +339,22 @@ do_unaligned_user (struct pt_regs *regs)
}
#endif
+/* Handle debug events.
+ * When CONFIG_HAVE_HW_BREAKPOINT is on this handler is called with
+ * preemption disabled to avoid rescheduling and keep mapping of hardware
+ * breakpoint structures to debug registers intact, so that
+ * DEBUGCAUSE.DBNUM could be used in case of data breakpoint hit.
+ */
void
do_debug(struct pt_regs *regs)
{
-#ifdef CONFIG_KGDB
- /* If remote debugging is configured AND enabled, we give control to
- * kgdb. Otherwise, we fall through, perhaps giving control to the
- * native debugger.
- */
-
- if (gdb_enter) {
- extern void gdb_handle_exception(struct pt_regs *);
- gdb_handle_exception(regs);
- return_from_debug_flag = 1;
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ int ret = check_hw_breakpoint(regs);
+
+ preempt_enable();
+ if (ret == 0)
return;
- }
#endif
-
__die_if_kernel("Breakpoint in kernel", regs, SIGKILL);
/* If in user mode, send SIGTRAP signal to current process */
@@ -364,6 +388,15 @@ static void trap_init_excsave(void)
__asm__ __volatile__("wsr %0, excsave1\n" : : "a" (excsave1));
}
+static void trap_init_debug(void)
+{
+ unsigned long debugsave = (unsigned long)this_cpu_ptr(&debug_table);
+
+ this_cpu_ptr(&debug_table)->debug_exception = debug_exception;
+ __asm__ __volatile__("wsr %0, excsave" __stringify(XCHAL_DEBUGLEVEL)
+ :: "a"(debugsave));
+}
+
/*
* Initialize dispatch tables.
*
@@ -407,12 +440,14 @@ void __init trap_init(void)
/* Initialize EXCSAVE_1 to hold the address of the exception table. */
trap_init_excsave();
+ trap_init_debug();
}
#ifdef CONFIG_SMP
void secondary_trap_init(void)
{
trap_init_excsave();
+ trap_init_debug();
}
#endif
diff --git a/arch/xtensa/kernel/vectors.S b/arch/xtensa/kernel/vectors.S
index fc25318e7..332e9d635 100644
--- a/arch/xtensa/kernel/vectors.S
+++ b/arch/xtensa/kernel/vectors.S
@@ -601,7 +601,9 @@ ENDPROC(window_overflow_restore_a0_fixup)
ENTRY(_DebugInterruptVector)
- xsr a0, SREG_EXCSAVE + XCHAL_DEBUGLEVEL
+ xsr a3, SREG_EXCSAVE + XCHAL_DEBUGLEVEL
+ s32i a0, a3, DT_DEBUG_SAVE
+ l32i a0, a3, DT_DEBUG_EXCEPTION
jx a0
ENDPROC(_DebugInterruptVector)
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-06 01:37:10 +0000