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Diffstat (limited to 'arch/x86/kernel/kgdb.c')
-rw-r--r--arch/x86/kernel/kgdb.c110
1 files changed, 70 insertions, 40 deletions
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index bfba6019d762..01ab17ae2ae7 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -47,20 +47,8 @@
#include <asm/debugreg.h>
#include <asm/apicdef.h>
#include <asm/system.h>
-
#include <asm/apic.h>
-/*
- * Put the error code here just in case the user cares:
- */
-static int gdb_x86errcode;
-
-/*
- * Likewise, the vector number here (since GDB only gets the signal
- * number through the usual means, and that's not very specific):
- */
-static int gdb_x86vector = -1;
-
/**
* pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
* @gdb_regs: A pointer to hold the registers in the order GDB wants.
@@ -211,6 +199,8 @@ static struct hw_breakpoint {
struct perf_event **pev;
} breakinfo[4];
+static unsigned long early_dr7;
+
static void kgdb_correct_hw_break(void)
{
int breakno;
@@ -222,6 +212,14 @@ static void kgdb_correct_hw_break(void)
int cpu = raw_smp_processor_id();
if (!breakinfo[breakno].enabled)
continue;
+ if (dbg_is_early) {
+ set_debugreg(breakinfo[breakno].addr, breakno);
+ early_dr7 |= encode_dr7(breakno,
+ breakinfo[breakno].len,
+ breakinfo[breakno].type);
+ set_debugreg(early_dr7, 7);
+ continue;
+ }
bp = *per_cpu_ptr(breakinfo[breakno].pev, cpu);
info = counter_arch_bp(bp);
if (bp->attr.disabled != 1)
@@ -236,7 +234,8 @@ static void kgdb_correct_hw_break(void)
if (!val)
bp->attr.disabled = 0;
}
- hw_breakpoint_restore();
+ if (!dbg_is_early)
+ hw_breakpoint_restore();
}
static int hw_break_reserve_slot(int breakno)
@@ -245,6 +244,9 @@ static int hw_break_reserve_slot(int breakno)
int cnt = 0;
struct perf_event **pevent;
+ if (dbg_is_early)
+ return 0;
+
for_each_online_cpu(cpu) {
cnt++;
pevent = per_cpu_ptr(breakinfo[breakno].pev, cpu);
@@ -270,6 +272,9 @@ static int hw_break_release_slot(int breakno)
struct perf_event **pevent;
int cpu;
+ if (dbg_is_early)
+ return 0;
+
for_each_online_cpu(cpu) {
pevent = per_cpu_ptr(breakinfo[breakno].pev, cpu);
if (dbg_release_bp_slot(*pevent))
@@ -314,7 +319,11 @@ static void kgdb_remove_all_hw_break(void)
bp = *per_cpu_ptr(breakinfo[i].pev, cpu);
if (bp->attr.disabled == 1)
continue;
- arch_uninstall_hw_breakpoint(bp);
+ if (dbg_is_early)
+ early_dr7 &= ~encode_dr7(i, breakinfo[i].len,
+ breakinfo[i].type);
+ else
+ arch_uninstall_hw_breakpoint(bp);
bp->attr.disabled = 1;
}
}
@@ -391,6 +400,11 @@ void kgdb_disable_hw_debug(struct pt_regs *regs)
for (i = 0; i < 4; i++) {
if (!breakinfo[i].enabled)
continue;
+ if (dbg_is_early) {
+ early_dr7 &= ~encode_dr7(i, breakinfo[i].len,
+ breakinfo[i].type);
+ continue;
+ }
bp = *per_cpu_ptr(breakinfo[i].pev, cpu);
if (bp->attr.disabled == 1)
continue;
@@ -399,23 +413,6 @@ void kgdb_disable_hw_debug(struct pt_regs *regs)
}
}
-/**
- * kgdb_post_primary_code - Save error vector/code numbers.
- * @regs: Original pt_regs.
- * @e_vector: Original error vector.
- * @err_code: Original error code.
- *
- * This is needed on architectures which support SMP and KGDB.
- * This function is called after all the slave cpus have been put
- * to a know spin state and the primary CPU has control over KGDB.
- */
-void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code)
-{
- /* primary processor is completely in the debugger */
- gdb_x86vector = e_vector;
- gdb_x86errcode = err_code;
-}
-
#ifdef CONFIG_SMP
/**
* kgdb_roundup_cpus - Get other CPUs into a holding pattern
@@ -567,7 +564,7 @@ static int __kgdb_notify(struct die_args *args, unsigned long cmd)
return NOTIFY_DONE;
}
- if (kgdb_handle_exception(args->trapnr, args->signr, args->err, regs))
+ if (kgdb_handle_exception(args->trapnr, args->signr, cmd, regs))
return NOTIFY_DONE;
/* Must touch watchdog before return to normal operation */
@@ -575,6 +572,24 @@ static int __kgdb_notify(struct die_args *args, unsigned long cmd)
return NOTIFY_STOP;
}
+int kgdb_ll_trap(int cmd, const char *str,
+ struct pt_regs *regs, long err, int trap, int sig)
+{
+ struct die_args args = {
+ .regs = regs,
+ .str = str,
+ .err = err,
+ .trapnr = trap,
+ .signr = sig,
+
+ };
+
+ if (!kgdb_io_module_registered)
+ return NOTIFY_DONE;
+
+ return __kgdb_notify(&args, cmd);
+}
+
static int
kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
{
@@ -605,42 +620,52 @@ static struct notifier_block kgdb_notifier = {
*/
int kgdb_arch_init(void)
{
+ return register_die_notifier(&kgdb_notifier);
+}
+
+static void kgdb_hw_overflow_handler(struct perf_event *event, int nmi,
+ struct perf_sample_data *data, struct pt_regs *regs)
+{
+ kgdb_ll_trap(DIE_DEBUG, "debug", regs, 0, 0, SIGTRAP);
+}
+
+void kgdb_arch_late(void)
+{
int i, cpu;
- int ret;
struct perf_event_attr attr;
struct perf_event **pevent;
- ret = register_die_notifier(&kgdb_notifier);
- if (ret != 0)
- return ret;
/*
* Pre-allocate the hw breakpoint structions in the non-atomic
* portion of kgdb because this operation requires mutexs to
* complete.
*/
+ hw_breakpoint_init(&attr);
attr.bp_addr = (unsigned long)kgdb_arch_init;
- attr.type = PERF_TYPE_BREAKPOINT;
attr.bp_len = HW_BREAKPOINT_LEN_1;
attr.bp_type = HW_BREAKPOINT_W;
attr.disabled = 1;
for (i = 0; i < 4; i++) {
+ if (breakinfo[i].pev)
+ continue;
breakinfo[i].pev = register_wide_hw_breakpoint(&attr, NULL);
if (IS_ERR(breakinfo[i].pev)) {
- printk(KERN_ERR "kgdb: Could not allocate hw breakpoints\n");
+ printk(KERN_ERR "kgdb: Could not allocate hw"
+ "breakpoints\nDisabling the kernel debugger\n");
breakinfo[i].pev = NULL;
kgdb_arch_exit();
- return -1;
+ return;
}
for_each_online_cpu(cpu) {
pevent = per_cpu_ptr(breakinfo[i].pev, cpu);
pevent[0]->hw.sample_period = 1;
+ pevent[0]->overflow_handler = kgdb_hw_overflow_handler;
if (pevent[0]->destroy != NULL) {
pevent[0]->destroy = NULL;
release_bp_slot(*pevent);
}
}
}
- return ret;
}
/**
@@ -690,6 +715,11 @@ unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs)
return instruction_pointer(regs);
}
+void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
+{
+ regs->ip = ip;
+}
+
struct kgdb_arch arch_kgdb_ops = {
/* Breakpoint instruction: */
.gdb_bpt_instr = { 0xcc },
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