git: f242c47ee278 - main - arm64: Support hardware breakpoints
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Date: Fri, 12 Apr 2024 09:37:43 UTC
The branch main has been updated by andrew:
URL: https://cgit.FreeBSD.org/src/commit/?id=f242c47ee278e8e119e98b8f4f00e52fbd0d4efd
commit f242c47ee278e8e119e98b8f4f00e52fbd0d4efd
Author: Andrew Turner <andrew@FreeBSD.org>
AuthorDate: 2024-03-12 17:14:38 +0000
Commit: Andrew Turner <andrew@FreeBSD.org>
CommitDate: 2024-04-12 09:32:56 +0000
arm64: Support hardware breakpoints
As with watchpoints allow the kernel debugger to set hardware
breakpoints on arm64.
These have been tested to work in both the ddb and gdb backends.
Reviewed by: jhb (earlier version)
Sponsored by: Arm Ltd
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D44355
---
sys/arm64/arm64/db_trace.c | 7 +++
sys/arm64/arm64/debug_monitor.c | 99 +++++++++++++++++++++++++++++++++++++++
sys/arm64/arm64/gdb_machdep.c | 9 +++-
sys/arm64/include/db_machdep.h | 3 ++
sys/arm64/include/debug_monitor.h | 1 +
sys/arm64/include/kdb.h | 2 +
6 files changed, 120 insertions(+), 1 deletion(-)
diff --git a/sys/arm64/arm64/db_trace.c b/sys/arm64/arm64/db_trace.c
index 4bc6af26a023..7b0fdeaeba29 100644
--- a/sys/arm64/arm64/db_trace.c
+++ b/sys/arm64/arm64/db_trace.c
@@ -47,6 +47,13 @@
#define FRAME_SERROR 3
#define FRAME_UNHANDLED 4
+void
+db_md_list_breakpoints(void)
+{
+
+ dbg_show_breakpoint();
+}
+
void
db_md_list_watchpoints(void)
{
diff --git a/sys/arm64/arm64/debug_monitor.c b/sys/arm64/arm64/debug_monitor.c
index 3d8e753e1c45..2e1a956ad75c 100644
--- a/sys/arm64/arm64/debug_monitor.c
+++ b/sys/arm64/arm64/debug_monitor.c
@@ -44,7 +44,9 @@
#include <machine/pcb.h>
#ifdef DDB
+#include <vm/vm.h>
#include <ddb/ddb.h>
+#include <ddb/db_break.h>
#include <ddb/db_sym.h>
#endif
@@ -59,6 +61,10 @@ static struct debug_monitor_state kernel_monitor = {
.dbg_flags = DBGMON_KERNEL
};
+static int dbg_setup_breakpoint(struct debug_monitor_state *monitor,
+ vm_offset_t addr);
+static int dbg_remove_breakpoint(struct debug_monitor_state *monitor,
+ vm_offset_t addr);
static int dbg_setup_watchpoint(struct debug_monitor_state *, vm_offset_t,
vm_size_t, enum dbg_access_t);
static int dbg_remove_watchpoint(struct debug_monitor_state *, vm_offset_t,
@@ -185,6 +191,18 @@ dbg_wb_write_reg(int reg, int n, uint64_t val)
}
#if defined(DDB) || defined(GDB)
+int
+kdb_cpu_set_breakpoint(vm_offset_t addr)
+{
+ return (dbg_setup_breakpoint(NULL, addr));
+}
+
+int
+kdb_cpu_clr_breakpoint(vm_offset_t addr)
+{
+ return (dbg_remove_breakpoint(NULL, addr));
+}
+
void
kdb_cpu_set_singlestep(void)
{
@@ -272,6 +290,33 @@ kdb_cpu_clr_watchpoint(vm_offset_t addr, vm_size_t size)
#endif /* DDB || GDB */
#ifdef DDB
+void
+dbg_show_breakpoint(void)
+{
+ db_breakpoint_t bkpt;
+ uint32_t bcr;
+ uint64_t addr;
+ int i;
+
+ db_printf("\nhardware breakpoints:\n");
+ db_printf(" break status count address symbol\n");
+ db_printf(" ----- -------- ----- ------------------ ------------------\n");
+ for (i = 0; i < dbg_breakpoint_num; i++) {
+ bcr = dbg_wb_read_reg(DBG_REG_BASE_BCR, i);
+ if ((bcr & DBG_WB_CTRL_E) != 0) {
+ addr = dbg_wb_read_reg(DBG_REG_BASE_BVR, i);
+ bkpt = db_find_breakpoint_here(addr);
+ db_printf(" %-5d %-8s %-5d 0x%16lx ",
+ i, "enabled", bkpt == NULL ? -1 : bkpt->count,
+ addr);
+ db_printsym((db_addr_t)addr, DB_STGY_ANY);
+ db_printf("\n");
+ } else {
+ db_printf(" %-5d disabled\n", i);
+ }
+ }
+}
+
static const char *
dbg_watchtype_str(uint32_t type)
{
@@ -394,6 +439,60 @@ dbg_find_slot(struct debug_monitor_state *monitor, enum dbg_t type,
return (-1);
}
+static int
+dbg_setup_breakpoint(struct debug_monitor_state *monitor, vm_offset_t addr)
+{
+ uint64_t bcr_priv;
+ u_int i;
+
+ if (monitor == NULL)
+ monitor = &kernel_monitor;
+
+ i = dbg_find_free_slot(monitor, DBG_TYPE_BREAKPOINT);
+ if (i == -1) {
+ printf("Can not find slot for breakpoint, max %d"
+ " breakpoints supported\n", dbg_breakpoint_num);
+ return (EBUSY);
+ }
+
+ if ((monitor->dbg_flags & DBGMON_KERNEL) == 0)
+ bcr_priv = DBG_WB_CTRL_EL0;
+ else
+ bcr_priv = DBG_WB_CTRL_EL1;
+
+ monitor->dbg_bvr[i] = addr;
+ monitor->dbg_bcr[i] = (0xf << 5) | bcr_priv | DBG_WB_CTRL_E;
+ monitor->dbg_enable_count++;
+ monitor->dbg_flags |= DBGMON_ENABLED;
+ dbg_register_sync(monitor);
+
+ return (0);
+}
+
+static int
+dbg_remove_breakpoint(struct debug_monitor_state *monitor, vm_offset_t addr)
+{
+ u_int i;
+
+ if (monitor == NULL)
+ monitor = &kernel_monitor;
+
+ i = dbg_find_slot(monitor, DBG_TYPE_BREAKPOINT, addr);
+ if (i == -1) {
+ printf("Can not find breakpoint for address 0%lx\n", addr);
+ return (i);
+ }
+
+ monitor->dbg_bvr[i] = 0;
+ monitor->dbg_bcr[i] = 0;
+ monitor->dbg_enable_count--;
+ if (monitor->dbg_enable_count == 0)
+ monitor->dbg_flags &= ~DBGMON_ENABLED;
+ dbg_register_sync(monitor);
+
+ return (0);
+}
+
static int
dbg_setup_watchpoint(struct debug_monitor_state *monitor, vm_offset_t addr,
vm_size_t size, enum dbg_access_t access)
diff --git a/sys/arm64/arm64/gdb_machdep.c b/sys/arm64/arm64/gdb_machdep.c
index 7b21675ea927..04c69e5f6079 100644
--- a/sys/arm64/arm64/gdb_machdep.c
+++ b/sys/arm64/arm64/gdb_machdep.c
@@ -121,9 +121,16 @@ void
gdb_cpu_stop_reason(int type, int code __unused)
{
- if (type == EXCP_WATCHPT_EL1) {
+ switch (type) {
+ case EXCP_WATCHPT_EL1:
gdb_tx_str("watch:");
gdb_tx_varhex((uintmax_t)READ_SPECIALREG(far_el1));
gdb_tx_char(';');
+ break;
+ case EXCP_BRKPT_EL1:
+ gdb_tx_str("hwbreak:;");
+ break;
+ default:
+ break;
}
}
diff --git a/sys/arm64/include/db_machdep.h b/sys/arm64/include/db_machdep.h
index 45b97443aec5..5dc496ca851d 100644
--- a/sys/arm64/include/db_machdep.h
+++ b/sys/arm64/include/db_machdep.h
@@ -40,6 +40,9 @@
#define T_SINGLESTEP (EXCP_SOFTSTP_EL1)
#define T_WATCHPOINT (EXCP_WATCHPT_EL1)
+#define HAS_HW_BREAKPOINT
+#define NHBREAKPOINTS 16
+
typedef vm_offset_t db_addr_t;
typedef long db_expr_t;
diff --git a/sys/arm64/include/debug_monitor.h b/sys/arm64/include/debug_monitor.h
index 578e90db7f12..8698f21a7c2a 100644
--- a/sys/arm64/include/debug_monitor.h
+++ b/sys/arm64/include/debug_monitor.h
@@ -56,6 +56,7 @@ void dbg_monitor_init(void);
void dbg_register_sync(struct debug_monitor_state *);
#ifdef DDB
+void dbg_show_breakpoint(void);
void dbg_show_watchpoint(void);
#endif
diff --git a/sys/arm64/include/kdb.h b/sys/arm64/include/kdb.h
index aa36e7e756f9..3148b7df7d1b 100644
--- a/sys/arm64/include/kdb.h
+++ b/sys/arm64/include/kdb.h
@@ -37,6 +37,8 @@
void kdb_cpu_clear_singlestep(void);
void kdb_cpu_set_singlestep(void);
+int kdb_cpu_set_breakpoint(vm_offset_t addr);
+int kdb_cpu_clr_breakpoint(vm_offset_t addr);
int kdb_cpu_set_watchpoint(vm_offset_t addr, size_t size, int access);
int kdb_cpu_clr_watchpoint(vm_offset_t addr, size_t size);