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authorLinus Torvalds <torvalds@linux-foundation.org>2010-05-21 11:10:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-21 11:10:41 -0700
commitac3ee84c604502240122c47b52f0542ec8774f15 (patch)
treefa74b50e310af6cef3298a052514b2d42b260d6b /arch
parent90b9a32d8f441369b2f97a765d2d957b531eb653 (diff)
parent4fe1da4ebc18c4c42fa56c228447f68033fce5f0 (diff)
downloadlinux-ac3ee84c604502240122c47b52f0542ec8774f15.tar.bz2
Merge branch 'dbg-early-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'dbg-early-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: echi-dbgp: Add kernel debugger support for the usb debug port earlyprintk,vga,kdb: Fix \b and \r for earlyprintk=vga with kdb kgdboc: Add ekgdboc for early use of the kernel debugger x86,early dr regs,kgdb: Allow kernel debugger early dr register access x86,kgdb: Implement early hardware breakpoint debugging x86, kgdb, init: Add early and late debug states x86, kgdb: early trap init for early debug
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/processor.h2
-rw-r--r--arch/x86/kernel/cpu/common.c29
-rw-r--r--arch/x86/kernel/early_printk.c8
-rw-r--r--arch/x86/kernel/kgdb.c47
-rw-r--r--arch/x86/kernel/setup.c1
-rw-r--r--arch/x86/kernel/traps.c14
6 files changed, 76 insertions, 25 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 5a51379dcbe4..7e5c6a60b8ee 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -789,6 +789,8 @@ static inline void wbinvd_halt(void)
extern void enable_sep_cpu(void);
extern int sysenter_setup(void);
+extern void early_trap_init(void);
+
/* Defined in head.S */
extern struct desc_ptr early_gdt_descr;
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index c1c00d0b1692..cc83a002786e 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1084,6 +1084,20 @@ static void clear_all_debug_regs(void)
}
}
+#ifdef CONFIG_KGDB
+/*
+ * Restore debug regs if using kgdbwait and you have a kernel debugger
+ * connection established.
+ */
+static void dbg_restore_debug_regs(void)
+{
+ if (unlikely(kgdb_connected && arch_kgdb_ops.correct_hw_break))
+ arch_kgdb_ops.correct_hw_break();
+}
+#else /* ! CONFIG_KGDB */
+#define dbg_restore_debug_regs()
+#endif /* ! CONFIG_KGDB */
+
/*
* cpu_init() initializes state that is per-CPU. Some data is already
* initialized (naturally) in the bootstrap process, such as the GDT
@@ -1174,18 +1188,8 @@ void __cpuinit cpu_init(void)
load_TR_desc();
load_LDT(&init_mm.context);
-#ifdef CONFIG_KGDB
- /*
- * If the kgdb is connected no debug regs should be altered. This
- * is only applicable when KGDB and a KGDB I/O module are built
- * into the kernel and you are using early debugging with
- * kgdbwait. KGDB will control the kernel HW breakpoint registers.
- */
- if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
- arch_kgdb_ops.correct_hw_break();
- else
-#endif
- clear_all_debug_regs();
+ clear_all_debug_regs();
+ dbg_restore_debug_regs();
fpu_init();
@@ -1239,6 +1243,7 @@ void __cpuinit cpu_init(void)
#endif
clear_all_debug_regs();
+ dbg_restore_debug_regs();
/*
* Force FPU initialization:
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index b9c830c12b4a..fa99bae75ace 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -41,6 +41,14 @@ static void early_vga_write(struct console *con, const char *str, unsigned n)
writew(0x720, VGABASE + 2*(max_xpos*j + i));
current_ypos = max_ypos-1;
}
+#ifdef CONFIG_KGDB_KDB
+ if (c == '\b') {
+ if (current_xpos > 0)
+ current_xpos--;
+ } else if (c == '\r') {
+ current_xpos = 0;
+ } else
+#endif
if (c == '\n') {
current_xpos = 0;
current_ypos++;
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index 95b89d4cb8f1..4f4af75b9482 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -199,6 +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;
@@ -210,6 +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)
@@ -224,7 +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)
@@ -233,6 +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);
@@ -258,6 +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))
@@ -302,7 +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;
}
}
@@ -379,6 +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;
@@ -596,14 +622,15 @@ static struct notifier_block kgdb_notifier = {
*/
int kgdb_arch_init(void)
{
+ return register_die_notifier(&kgdb_notifier);
+}
+
+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
@@ -615,12 +642,15 @@ int kgdb_arch_init(void)
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);
@@ -631,7 +661,6 @@ int kgdb_arch_init(void)
}
}
}
- return ret;
}
/**
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index c4851eff57b3..e8029896309a 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -725,6 +725,7 @@ void __init setup_arch(char **cmdline_p)
/* VMI may relocate the fixmap; do this before touching ioremap area */
vmi_init();
+ early_trap_init();
early_cpu_init();
early_ioremap_init();
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 7eaad4c5110a..142d70c74b02 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -808,6 +808,16 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
}
#endif
+/* Set of traps needed for early debugging. */
+void __init early_trap_init(void)
+{
+ set_intr_gate_ist(1, &debug, DEBUG_STACK);
+ /* int3 can be called from all */
+ set_system_intr_gate_ist(3, &int3, DEBUG_STACK);
+ set_intr_gate(14, &page_fault);
+ load_idt(&idt_descr);
+}
+
void __init trap_init(void)
{
int i;
@@ -821,10 +831,7 @@ void __init trap_init(void)
#endif
set_intr_gate(0, &divide_error);
- set_intr_gate_ist(1, &debug, DEBUG_STACK);
set_intr_gate_ist(2, &nmi, NMI_STACK);
- /* int3 can be called from all */
- set_system_intr_gate_ist(3, &int3, DEBUG_STACK);
/* int4 can be called from all */
set_system_intr_gate(4, &overflow);
set_intr_gate(5, &bounds);
@@ -840,7 +847,6 @@ void __init trap_init(void)
set_intr_gate(11, &segment_not_present);
set_intr_gate_ist(12, &stack_segment, STACKFAULT_STACK);
set_intr_gate(13, &general_protection);
- set_intr_gate(14, &page_fault);
set_intr_gate(15, &spurious_interrupt_bug);
set_intr_gate(16, &coprocessor_error);
set_intr_gate(17, &alignment_check);