* Re: [PATCH][6/6] A different KGDB stub
[not found] <20040212000408.GG19676@smtp.west.cox.net.suse.lists.linux.kernel>
@ 2004-02-12 6:43 ` Andi Kleen
2004-02-12 15:50 ` Tom Rini
2004-02-12 18:32 ` Tom Rini
0 siblings, 2 replies; 10+ messages in thread
From: Andi Kleen @ 2004-02-12 6:43 UTC (permalink / raw)
To: Tom Rini; +Cc: akpm, linux-kernel
Tom Rini <trini@kernel.crashing.org> writes:
Andrew, please don't add this broken version.
> @@ -219,7 +219,7 @@
> jnc sysret_signal
> sti
> pushq %rdi
> - call schedule
> + call user_schedule
I really don't like this change. It is completely useless because you
can get the pt_regs as well from the stack. Please don't add it.
George's stub also didn't need it.
> +#ifdef CONFIG_KGDB_THREAD
> +ENTRY(kern_schedule)
Similar. No such crap please.
> @@ -317,13 +318,26 @@
> return;
>
> sum = read_pda(apic_timer_irqs);
> - if (last_irq_sums[cpu] == sum) {
> + if (atomic_read(&debugger_active)) {
> +
> + /*
> + * The machine is in debugger, hold this cpu if already
> + * not held.
> + */
> + debugger_nmihook(cpu, regs);
> + alert_counter[cpu] = 0;
This should be a notify_die.
> + } else if (last_irq_sums[cpu] == sum) {
> +
> /*
> * Ayiee, looks like this CPU is stuck ...
> * wait a few IRQs (5 seconds) before doing the oops ...
> */
> alert_counter[cpu]++;
> if (alert_counter[cpu] == 5*nmi_hz) {
> +
> + CHK_DEBUGGER(2,SIGSEGV,0,regs,)
> +
> if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_BAD) {
That's complete crap. You have a debugger hook and you add your own
hook one line before it. Please fix that.
I note that the old stub in -mm* didn't need such wards.
>
> void die(const char * str, struct pt_regs * regs, long err)
> {
> + CHK_DEBUGGER(1,SIGTRAP,err,regs,)
Same issue here. All the CHK_DEBUGGER are redundant with notify_die.
> --- a/include/asm-x86_64/processor.h Wed Feb 11 15:42:06 2004
> +++ b/include/asm-x86_64/processor.h Wed Feb 11 15:42:06 2004
> @@ -252,6 +252,7 @@
> unsigned long *io_bitmap_ptr;
> /* cached TLS descriptors. */
> u64 tls_array[GDT_ENTRY_TLS_ENTRIES];
> + void *debuggerinfo;
> };
This should not be needed
> #define INIT_THREAD {}
> --- a/include/asm-x86_64/system.h Wed Feb 11 15:42:06 2004
> +++ b/include/asm-x86_64/system.h Wed Feb 11 15:42:06 2004
> @@ -19,6 +19,56 @@
> #define __SAVE(reg,offset) "movq %%" #reg ",(14-" #offset ")*8(%%rsp)\n\t"
> #define __RESTORE(reg,offset) "movq (14-" #offset ")*8(%%rsp),%%" #reg "\n\t"
>
> +/* #ifdef CONFIG_KGDB */
> +
> +/* full frame for the debug stub */
> +/* Should be replaced with a dwarf2 cie/fde description, then gdb could
> + figure it out all by itself. */
> +struct save_context_frame {
That's completely broken too. We have a full CFI description in the kernel
now, so this isn't needed anymore.
-Andi
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH][6/6] A different KGDB stub
2004-02-12 6:43 ` [PATCH][6/6] A different KGDB stub Andi Kleen
@ 2004-02-12 15:50 ` Tom Rini
2004-02-13 3:00 ` Andi Kleen
2004-02-12 18:32 ` Tom Rini
1 sibling, 1 reply; 10+ messages in thread
From: Tom Rini @ 2004-02-12 15:50 UTC (permalink / raw)
To: Andi Kleen; +Cc: akpm, linux-kernel, Amit S. Kale
On Thu, Feb 12, 2004 at 07:43:04AM +0100, Andi Kleen wrote:
> Tom Rini <trini@kernel.crashing.org> writes:
>
> Andrew, please don't add this broken version.
>
> > @@ -219,7 +219,7 @@
> > jnc sysret_signal
> > sti
> > pushq %rdi
> > - call schedule
> > + call user_schedule
>
> I really don't like this change. It is completely useless because you
> can get the pt_regs as well from the stack. Please don't add it.
> George's stub also didn't need it.
>
> > +#ifdef CONFIG_KGDB_THREAD
> > +ENTRY(kern_schedule)
>
> Similar. No such crap please.
Amit? I seem to recall you and George (and Andi?) talking about how to
get rid of these bits, did you ever write any of it up?
> > @@ -317,13 +318,26 @@
> > return;
> >
> > sum = read_pda(apic_timer_irqs);
> > - if (last_irq_sums[cpu] == sum) {
> > + if (atomic_read(&debugger_active)) {
> > +
> > + /*
> > + * The machine is in debugger, hold this cpu if already
> > + * not held.
> > + */
> > + debugger_nmihook(cpu, regs);
> > + alert_counter[cpu] = 0;
>
> This should be a notify_die.
Not being firmiliar with x86_64, do you mean:
/*
* The machine is in debugger, hold this cpu if already
* not held.
*/
notify_die(cpu, regs);
? Or so?
> > + } else if (last_irq_sums[cpu] == sum) {
> > +
> > /*
> > * Ayiee, looks like this CPU is stuck ...
> > * wait a few IRQs (5 seconds) before doing the oops ...
> > */
> > alert_counter[cpu]++;
> > if (alert_counter[cpu] == 5*nmi_hz) {
> > +
> > + CHK_DEBUGGER(2,SIGSEGV,0,regs,)
> > +
> > if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_BAD) {
>
> That's complete crap. You have a debugger hook and you add your own
> hook one line before it. Please fix that.
Yes, Amit's version does this on PPC32 as well, and I'd like to change
it, but I've been cleaning up other things.
> > --- a/include/asm-x86_64/processor.h Wed Feb 11 15:42:06 2004
> > +++ b/include/asm-x86_64/processor.h Wed Feb 11 15:42:06 2004
> > @@ -252,6 +252,7 @@
> > unsigned long *io_bitmap_ptr;
> > /* cached TLS descriptors. */
> > u64 tls_array[GDT_ENTRY_TLS_ENTRIES];
> > + void *debuggerinfo;
> > };
>
> This should not be needed
What would be used instead to pass around the pt_regs?
> > --- a/include/asm-x86_64/system.h Wed Feb 11 15:42:06 2004
> > +++ b/include/asm-x86_64/system.h Wed Feb 11 15:42:06 2004
> > @@ -19,6 +19,56 @@
> > #define __SAVE(reg,offset) "movq %%" #reg ",(14-" #offset ")*8(%%rsp)\n\t"
> > #define __RESTORE(reg,offset) "movq (14-" #offset ")*8(%%rsp),%%" #reg "\n\t"
> >
> > +/* #ifdef CONFIG_KGDB */
> > +
> > +/* full frame for the debug stub */
> > +/* Should be replaced with a dwarf2 cie/fde description, then gdb could
> > + figure it out all by itself. */
> > +struct save_context_frame {
>
> That's completely broken too. We have a full CFI description in the kernel
> now, so this isn't needed anymore.
Part of why I'm trying to get this into -mm is so that someone who has
the hw and knowledge can try and merge some of the things that the other
stubs got right into the stub that every arch can use.
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH][6/6] A different KGDB stub
2004-02-13 3:00 ` Andi Kleen
@ 2004-02-12 16:27 ` Tom Rini
2004-02-16 19:47 ` Pavel Machek
0 siblings, 1 reply; 10+ messages in thread
From: Tom Rini @ 2004-02-12 16:27 UTC (permalink / raw)
To: Andi Kleen; +Cc: akpm, linux-kernel, amitkale
On Fri, Feb 13, 2004 at 04:00:41AM +0100, Andi Kleen wrote:
> On Thu, 12 Feb 2004 08:50:55 -0700
> Tom Rini <trini@kernel.crashing.org> wrote:
> >
> > Part of why I'm trying to get this into -mm is so that someone who has
> > the hw and knowledge can try and merge some of the things that the other
> > stubs got right into the stub that every arch can use.
>
> The kgdb stub in current -mm* does all the things I mentioned correctly.
Yes, and it also makes every arch implement the entire stub and provide
its own serial driver. Having said that, I'll try and pull out more of
the things that the other stub gets right, but I don't have any x86_64
hw (nor toolchain) so I can't test any of the x86_64 changes I make.
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH][6/6] A different KGDB stub
2004-02-12 6:43 ` [PATCH][6/6] A different KGDB stub Andi Kleen
2004-02-12 15:50 ` Tom Rini
@ 2004-02-12 18:32 ` Tom Rini
1 sibling, 0 replies; 10+ messages in thread
From: Tom Rini @ 2004-02-12 18:32 UTC (permalink / raw)
To: Andi Kleen; +Cc: akpm, linux-kernel
On Thu, Feb 12, 2004 at 07:43:04AM +0100, Andi Kleen wrote:
> Tom Rini <trini@kernel.crashing.org> writes:
[snip]
> > --- a/include/asm-x86_64/processor.h Wed Feb 11 15:42:06 2004
> > +++ b/include/asm-x86_64/processor.h Wed Feb 11 15:42:06 2004
> > @@ -252,6 +252,7 @@
> > unsigned long *io_bitmap_ptr;
> > /* cached TLS descriptors. */
> > u64 tls_array[GDT_ENTRY_TLS_ENTRIES];
> > + void *debuggerinfo;
> > };
>
> This should not be needed
OK. Unless there is a difference in this respect on i386 vs x86_64 in
2.6.3-rc2-mm1, this is needed for the thread support which is in this
version, but not the -mm version. OTOH, if there is a cleaner way of
doing this, and there indeed might be (I need to sit down and re-read
some of the previous threads), I'm all ears, not tied to doing it that
way, etc, etc.
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH][6/6] A different KGDB stub
2004-02-12 15:50 ` Tom Rini
@ 2004-02-13 3:00 ` Andi Kleen
2004-02-12 16:27 ` Tom Rini
0 siblings, 1 reply; 10+ messages in thread
From: Andi Kleen @ 2004-02-13 3:00 UTC (permalink / raw)
To: Tom Rini; +Cc: akpm, linux-kernel, amitkale
On Thu, 12 Feb 2004 08:50:55 -0700
Tom Rini <trini@kernel.crashing.org> wrote:
>
> Part of why I'm trying to get this into -mm is so that someone who has
> the hw and knowledge can try and merge some of the things that the other
> stubs got right into the stub that every arch can use.
The kgdb stub in current -mm* does all the things I mentioned correctly.
-Andi
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH][6/6] A different KGDB stub
2004-02-12 16:27 ` Tom Rini
@ 2004-02-16 19:47 ` Pavel Machek
0 siblings, 0 replies; 10+ messages in thread
From: Pavel Machek @ 2004-02-16 19:47 UTC (permalink / raw)
To: Tom Rini; +Cc: Andi Kleen, akpm, linux-kernel, amitkale
Hi!
> > > Part of why I'm trying to get this into -mm is so that someone who has
> > > the hw and knowledge can try and merge some of the things that the other
> > > stubs got right into the stub that every arch can use.
> >
> > The kgdb stub in current -mm* does all the things I mentioned correctly.
>
> Yes, and it also makes every arch implement the entire stub and provide
> its own serial driver. Having said that, I'll try and pull out more of
> the things that the other stub gets right, but I don't have any x86_64
> hw (nor toolchain) so I can't test any of the x86_64 changes I make.
I think I can help with that...
Pavel
--
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH][6/6] A different KGDB stub
2004-02-17 23:08 ` Pavel Machek
@ 2004-02-17 23:13 ` Tom Rini
0 siblings, 0 replies; 10+ messages in thread
From: Tom Rini @ 2004-02-17 23:13 UTC (permalink / raw)
To: Pavel Machek; +Cc: kernel list
On Wed, Feb 18, 2004 at 12:08:55AM +0100, Pavel Machek wrote:
> Hi!
>
> > > > The following is the x86_64-specific bits to this KGDB stub (Pavel, can
> > > > you give this a try please? Thanks).
> > >
> > > I can only see [0/6],[1/6] and [6/6] on l-k. Could you perhaps mail me
> > > complete diff against 2.6.2 to try? [Or against some other version I
> > > can get from kernel.org...)
> >
> > I'll blame the slow mailserver and hope they all get through
> > eventually.
>
> Yes, now only #2 is missing :-))).
>
> > The following is the patch before I split it up. Against 2.6.3-rc4 +
> > bk-netdev from 2.6.3-rc3-mm1 (otherwise kgdboe won't work at all):
>
> I'll try without kgdboe, first.
>
> I'm getting some compile errors, stay tuned.
I'm not surprised, sadly.
> Meanwhile: [and taking this public]
>
> arch/x86_64/kernel/x86_64-stub.c: this is really horrible name for a
> file. Can we have arch/x86_64/kernel/kgdb.c? or kgdb-stub.c at worst..
>
> also kernel/kgdb.c sounds better than kernel/kgdbstub.c.
Don't look at me for naming, when in doubt I call stuff 'simple' (see
arch/ppc/boot/simple, or CONFIG_PPC_SIMPLE_SERIAL, and I'm sure I'll do
it again). If people like kernel/kgdb.c (and arch/$(ARCH)/kernel/kgdb.c
or kgdb-stub.c) that's fine with me, so long as they're all consistent.
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH][6/6] A different KGDB stub
[not found] ` <20040217223817.GJ16881@smtp.west.cox.net>
@ 2004-02-17 23:08 ` Pavel Machek
2004-02-17 23:13 ` Tom Rini
0 siblings, 1 reply; 10+ messages in thread
From: Pavel Machek @ 2004-02-17 23:08 UTC (permalink / raw)
To: Tom Rini; +Cc: kernel list
Hi!
> > > The following is the x86_64-specific bits to this KGDB stub (Pavel, can
> > > you give this a try please? Thanks).
> >
> > I can only see [0/6],[1/6] and [6/6] on l-k. Could you perhaps mail me
> > complete diff against 2.6.2 to try? [Or against some other version I
> > can get from kernel.org...)
>
> I'll blame the slow mailserver and hope they all get through
> eventually.
Yes, now only #2 is missing :-))).
> The following is the patch before I split it up. Against 2.6.3-rc4 +
> bk-netdev from 2.6.3-rc3-mm1 (otherwise kgdboe won't work at all):
I'll try without kgdboe, first.
I'm getting some compile errors, stay tuned.
Meanwhile: [and taking this public]
arch/x86_64/kernel/x86_64-stub.c: this is really horrible name for a
file. Can we have arch/x86_64/kernel/kgdb.c? or kgdb-stub.c at worst..
also kernel/kgdb.c sounds better than kernel/kgdbstub.c.
Pavel
--
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH][6/6] A different KGDB stub
@ 2004-02-17 22:04 Tom Rini
[not found] ` <20040217223040.GA1560@elf.ucw.cz>
0 siblings, 1 reply; 10+ messages in thread
From: Tom Rini @ 2004-02-17 22:04 UTC (permalink / raw)
To: Andrew Morton, Kernel Mailing List; +Cc: Pavel Machek
The following is the x86_64-specific bits to this KGDB stub (Pavel, can
you give this a try please? Thanks).
arch/x86_64/Kconfig | 5
arch/x86_64/kernel/Makefile | 1
arch/x86_64/kernel/entry.S | 41 ++
arch/x86_64/kernel/irq.c | 2
arch/x86_64/kernel/nmi.c | 14
arch/x86_64/kernel/traps.c | 3
arch/x86_64/kernel/x86_64-stub.c | 551 +++++++++++++++++++++++++++++++++++++++
arch/x86_64/mm/fault.c | 6
include/asm-x86_64/kgdb.h | 57 ++++
include/asm-x86_64/processor.h | 1
include/asm-x86_64/system.h | 50 +++
11 files changed, 722 insertions(+), 9 deletions(-)
--- linux-2.6.3-rc4/arch/x86_64/Kconfig 2004-02-17 09:53:43.000000000 -0700
+++ linux-2.6.3-rc4-kgdb/arch/x86_64/Kconfig 2004-02-17 11:34:11.411950235 -0700
@@ -465,10 +465,7 @@ config IOMMU_LEAK
Add a simple leak tracer to the IOMMU code. This is useful when you
are debugging a buggy device driver that leaks IOMMU mappings.
-#config X86_REMOTE_DEBUG
-# bool "kgdb debugging stub"
-
-endmenu
+source "kernel/Kconfig.kgdb"
source "security/Kconfig"
--- linux-2.6.3-rc4/arch/x86_64/kernel/Makefile 2004-02-17 09:53:29.000000000 -0700
+++ linux-2.6.3-rc4-kgdb/arch/x86_64/kernel/Makefile 2004-02-17 11:34:09.374412669 -0700
@@ -24,6 +24,7 @@ obj-$(CONFIG_GART_IOMMU) += pci-gart.o a
obj-$(CONFIG_DUMMY_IOMMU) += pci-nommu.o pci-dma.o
obj-$(CONFIG_MODULES) += module.o
+obj-$(CONFIG_KGDB) += x86_64-stub.o
obj-y += topology.o
--- linux-2.6.3-rc4/arch/x86_64/kernel/entry.S 2004-02-17 09:52:01.000000000 -0700
+++ linux-2.6.3-rc4-kgdb/arch/x86_64/kernel/entry.S 2004-02-17 11:33:57.472113993 -0700
@@ -219,7 +219,7 @@ sysret_careful:
jnc sysret_signal
sti
pushq %rdi
- call schedule
+ call user_schedule
popq %rdi
jmp sysret_check
@@ -288,7 +288,7 @@ int_careful:
jnc int_very_careful
sti
pushq %rdi
- call schedule
+ call user_schedule
popq %rdi
jmp int_with_check
@@ -482,7 +482,7 @@ retint_careful:
jnc retint_signal
sti
pushq %rdi
- call schedule
+ call user_schedule
popq %rdi
GET_THREAD_INFO(%rcx)
cli
@@ -868,3 +868,38 @@ ENTRY(machine_check)
ENTRY(call_debug)
zeroentry do_call_debug
+#ifdef CONFIG_KGDB_THREAD
+ENTRY(kern_schedule)
+ subq $21*8,%rsp
+ movq %rax,10*8(%rsp)
+
+ movq %rsp,%rax
+ addq $21*8,%rax
+ movq %rax, 19*8(%rsp)
+
+ pushfq
+ popq 18*8(%rsp)
+
+ movq 21*8(%rsp),%rax
+ movq %rax,16*8(%rsp)
+
+ movq %rdi,14*8(%rsp)
+ movq %rsi,13*8(%rsp)
+ movq %rdx,12*8(%rsp)
+ movq %rcx,11*8(%rsp)
+
+ movq %r8, 9*8(%rsp)
+ movq %r9, 8*8(%rsp)
+ movq %r10,7*8(%rsp)
+ movq %r11,6*8(%rsp)
+ movq %rbx,5*8(%rsp)
+ movq %rbp,4*8(%rsp)
+ movq %r12,3*8(%rsp)
+ movq %r13,2*8(%rsp)
+ movq %r14,1*8(%rsp)
+ movq %r15,(%rsp)
+ call kern_do_schedule
+ movq 10*8(%rsp), %rax
+ addq $21*8,%rsp
+ ret
+#endif
--- linux-2.6.3-rc4/arch/x86_64/kernel/irq.c 2004-02-17 09:52:16.000000000 -0700
+++ linux-2.6.3-rc4-kgdb/arch/x86_64/kernel/irq.c 2004-02-17 11:33:59.629624327 -0700
@@ -405,6 +405,8 @@ out:
spin_unlock(&desc->lock);
irq_exit();
+
+ kgdb_process_breakpoint();
return 1;
}
--- linux-2.6.3-rc4/arch/x86_64/kernel/nmi.c 2004-02-17 09:52:26.000000000 -0700
+++ linux-2.6.3-rc4-kgdb/arch/x86_64/kernel/nmi.c 2004-02-17 11:34:00.374455281 -0700
@@ -24,6 +24,7 @@
#include <linux/module.h>
#include <linux/sysdev.h>
#include <linux/nmi.h>
+#include <linux/debugger.h>
#include <asm/smp.h>
#include <asm/mtrr.h>
@@ -317,13 +318,24 @@ void nmi_watchdog_tick (struct pt_regs *
return;
sum = read_pda(apic_timer_irqs);
- if (last_irq_sums[cpu] == sum) {
+ if (atomic_read(&debugger_active)) {
+
+ /*
+ * The machine is in debugger, hold this cpu if already
+ * not held.
+ */
+ debugger_nmihook(cpu, regs);
+ alert_counter[cpu] = 0;
+
+ } else if (last_irq_sums[cpu] == sum) {
+
/*
* Ayiee, looks like this CPU is stuck ...
* wait a few IRQs (5 seconds) before doing the oops ...
*/
alert_counter[cpu]++;
if (alert_counter[cpu] == 5*nmi_hz) {
+
if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_BAD) {
alert_counter[cpu] = 0;
return;
--- linux-2.6.3-rc4/arch/x86_64/kernel/traps.c 2004-02-17 09:49:51.000000000 -0700
+++ linux-2.6.3-rc4-kgdb/arch/x86_64/kernel/traps.c 2004-02-17 11:33:46.882517404 -0700
@@ -28,6 +28,7 @@
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/debugger.h>
#include <asm/system.h>
#include <asm/uaccess.h>
@@ -614,7 +615,7 @@ asmlinkage void do_debug(struct pt_regs
tsk->thread.debugreg6 = condition;
/* Mask out spurious TF errors due to lazy TF clearing */
- if (condition & DR_STEP) {
+ if (condition & DR_STEP && !debugger_step) {
/*
* The TF error should be masked out only if the current
* process is not traced and if the TRAP flag has been set
--- linux-2.6.3-rc4/arch/x86_64/kernel/x86_64-stub.c 1969-12-31 17:00:00.000000000 -0700
+++ linux-2.6.3-rc4-kgdb/arch/x86_64/kernel/x86_64-stub.c 2004-02-17 11:33:54.511785866 -0700
@@ -0,0 +1,551 @@
+/*
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ */
+
+/*
+ * Copyright (C) 2004 Amit S. Kale
+ * Copyright (C) 2000-2001 VERITAS Software Corporation.
+ * Copyright (C) 2002 Andi Kleen, SuSE Labs
+ */
+/****************************************************************************
+ * Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $
+ *
+ * Module name: remcom.c $
+ * Revision: 1.34 $
+ * Date: 91/03/09 12:29:49 $
+ * Contributor: Lake Stevens Instrument Division$
+ *
+ * Description: low level support for gdb debugger. $
+ *
+ * Considerations: only works on target hardware $
+ *
+ * Written by: Glenn Engel $
+ * Updated by: Amit Kale<akale@veritas.com>
+ * ModuleState: Experimental $
+ *
+ * NOTES: See Below $
+ *
+ * Modified for 386 by Jim Kingdon, Cygnus Support.
+ * Origianl kgdb, compatibility with 2.1.xx kernel by David Grothe <dave@gcom.com>
+ * Integrated into 2.2.5 kernel by Tigran Aivazian <tigran@sco.com>
+ * thread support,
+ * support for multiple processors,
+ * support for ia-32(x86) hardware debugging,
+ * Console support,
+ * handling nmi watchdog
+ * Amit S. Kale ( amitkale@emsyssoft.com )
+ *
+ * X86_64 changes from Andi Kleen's patch merged by Jim Houston
+ *
+ *
+ * To enable debugger support, two things need to happen. One, a
+ * call to set_debug_traps() is necessary in order to allow any breakpoints
+ * or error conditions to be properly intercepted and reported to gdb.
+ * Two, a breakpoint needs to be generated to begin communication. This
+ * is most easily accomplished by a call to breakpoint(). Breakpoint()
+ * simulates a breakpoint by executing an int 3.
+ *
+ *************
+ *
+ * The following gdb commands are supported:
+ *
+ * command function Return value
+ *
+ * g return the value of the CPU registers hex data or ENN
+ * G set the value of the CPU registers OK or ENN
+ *
+ * mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN
+ * MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN
+ *
+ * c Resume at current address SNN ( signal NN)
+ * cAA..AA Continue at address AA..AA SNN
+ *
+ * s Step one instruction SNN
+ * sAA..AA Step one instruction from AA..AA SNN
+ *
+ * k kill
+ *
+ * ? What was the last sigval ? SNN (signal NN)
+ *
+ * All commands and responses are sent with a packet which includes a
+ * checksum. A packet consists of
+ *
+ * $<packet info>#<checksum>.
+ *
+ * where
+ * <packet info> :: <characters representing the command or response>
+ * <checksum> :: < two hex digits computed as modulo 256 sum of <packetinfo>>
+ *
+ * When a packet is received, it is first acknowledged with either '+' or '-'.
+ * '+' indicates a successful transfer. '-' indicates a failed transfer.
+ *
+ * Example:
+ *
+ * Host: Reply:
+ * $m0,10#2a +$00010203040506070809101112131415#42
+ *
+ ****************************************************************************/
+
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <asm/system.h>
+#include <asm/ptrace.h> /* for linux pt_regs struct */
+#include <linux/kgdb.h>
+#ifdef CONFIG_GDB_CONSOLE
+#include <linux/console.h>
+#endif
+#include <linux/init.h>
+#include <linux/debugger.h>
+#include <asm/kdebug.h>
+
+/* Put the error code here just in case the user cares. */
+int gdb_x86_64errcode;
+/* Likewise, the vector number here (since GDB only gets the signal
+ number through the usual means, and that's not very specific). */
+int gdb_x86_64vector = -1;
+
+#if KGDB_MAX_NO_CPUS != 8
+#error change the definition of slavecpulocks
+#endif
+
+void regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+ gdb_regs[_RAX] = regs->rax;
+ gdb_regs[_RBX] = regs->rbx;
+ gdb_regs[_RCX] = regs->rcx;
+ gdb_regs[_RDX] = regs->rdx;
+ gdb_regs[_RSI] = regs->rsi;
+ gdb_regs[_RDI] = regs->rdi;
+ gdb_regs[_RBP] = regs->rbp;
+ gdb_regs[ _PS] = regs->eflags;
+ gdb_regs[ _PC] = regs->rip;
+ gdb_regs[ _R8] = regs->r8;
+ gdb_regs[ _R9] = regs->r9;
+ gdb_regs[_R10] = regs->r10;
+ gdb_regs[_R11] = regs->r11;
+ gdb_regs[_R12] = regs->r12;
+ gdb_regs[_R13] = regs->r13;
+ gdb_regs[_R14] = regs->r14;
+ gdb_regs[_R15] = regs->r15;
+ gdb_regs[_RSP] = regs->rsp;
+}
+
+struct task_struct *__switch_to(struct task_struct *prev_p,
+ struct task_struct *next_p);
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
+{
+ gdb_regs[_RAX] = 0;
+ gdb_regs[_RBX] = 0;
+ gdb_regs[_RCX] = 0;
+ gdb_regs[_RDX] = 0;
+ gdb_regs[_RSI] = 0;
+ gdb_regs[_RDI] = 0;
+ gdb_regs[_RBP] = 0;
+ gdb_regs[ _PS] = 0;
+ gdb_regs[ _PC] = (unsigned long) __switch_to;
+ gdb_regs[ _R8] = 0;
+ gdb_regs[ _R9] = 0;
+ gdb_regs[_R10] = 0;
+ gdb_regs[_R11] = 0;
+ gdb_regs[_R12] = 0;
+ gdb_regs[_R13] = 0;
+ gdb_regs[_R14] = 0;
+ gdb_regs[_R15] = 0;
+ gdb_regs[_RSP] = p->thread.rsp;
+}
+
+void gdb_regs_to_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+ regs->rax = gdb_regs[_RAX] ;
+ regs->rbx = gdb_regs[_RBX] ;
+ regs->rcx = gdb_regs[_RCX] ;
+ regs->rdx = gdb_regs[_RDX] ;
+ regs->rsi = gdb_regs[_RSI] ;
+ regs->rdi = gdb_regs[_RDI] ;
+ regs->rbp = gdb_regs[_RBP] ;
+ regs->eflags= gdb_regs[ _PS] ;
+ regs->rip = gdb_regs[ _PC] ;
+ regs->r8 = gdb_regs[ _R8] ;
+ regs->r9 = gdb_regs[ _R9] ;
+ regs->r10 = gdb_regs[ _R10] ;
+ regs->r11 = gdb_regs[ _R11] ;
+ regs->r12 = gdb_regs[ _R12] ;
+ regs->r13 = gdb_regs[ _R13] ;
+ regs->r14 = gdb_regs[ _R14] ;
+ regs->r15 = gdb_regs[ _R15] ;
+#if 0 /* can't change these */
+ regs->rsp = gdb_regs[_RSP] ;
+ regs->ss = gdb_regs[ _SS] ;
+ regs->fs = gdb_regs[ _FS] ;
+ regs->gs = gdb_regs[ _GS] ;
+#endif
+
+} /* gdb_regs_to_regs */
+
+
+struct hw_breakpoint {
+ unsigned enabled;
+ unsigned type;
+ unsigned len;
+ unsigned long addr;
+} breakinfo[4] = { {
+enabled:0}, {
+enabled:0}, {
+enabled:0}, {
+enabled:0}};
+
+void kgdb_correct_hw_break(void)
+{
+ int breakno;
+ int correctit;
+ int breakbit;
+ unsigned long dr7;
+
+ asm volatile ("movq %%db7, %0\n":"=r" (dr7) :);
+ do {
+ unsigned long addr0, addr1, addr2, addr3;
+ asm volatile ("movq %%db0, %0\n"
+ "movq %%db1, %1\n"
+ "movq %%db2, %2\n"
+ "movq %%db3, %3\n":"=r" (addr0), "=r"(addr1),
+ "=r"(addr2), "=r"(addr3):);
+ } while (0);
+ correctit = 0;
+ for (breakno = 0; breakno < 3; breakno++) {
+ breakbit = 2 << (breakno << 1);
+ if (!(dr7 & breakbit) && breakinfo[breakno].enabled) {
+ correctit = 1;
+ dr7 |= breakbit;
+ dr7 &= ~(0xf0000 << (breakno << 2));
+ dr7 |= (((breakinfo[breakno].len << 2) |
+ breakinfo[breakno].type) << 16) <<
+ (breakno << 2);
+ switch (breakno) {
+ case 0:
+ asm volatile ("movq %0, %%dr0\n"::"r"
+ (breakinfo[breakno].addr));
+ break;
+
+ case 1:
+ asm volatile ("movq %0, %%dr1\n"::"r"
+ (breakinfo[breakno].addr));
+ break;
+
+ case 2:
+ asm volatile ("movq %0, %%dr2\n"::"r"
+ (breakinfo[breakno].addr));
+ break;
+
+ case 3:
+ asm volatile ("movq %0, %%dr3\n"::"r"
+ (breakinfo[breakno].addr));
+ break;
+ }
+ } else if ((dr7 & breakbit) && !breakinfo[breakno].enabled) {
+ correctit = 1;
+ dr7 &= ~breakbit;
+ dr7 &= ~(0xf0000 << (breakno << 2));
+ }
+ }
+ if (correctit) {
+ asm volatile ("movq %0, %%db7\n"::"r" (dr7));
+ }
+}
+
+int kgdb_remove_hw_break(unsigned long addr, int type)
+{
+ int i, idx = -1;
+ for (i = 0; i < 4; i ++) {
+ if (breakinfo[i].addr == addr && breakinfo[i].enabled) {
+ idx = i;
+ break;
+ }
+ }
+ if (idx == -1)
+ return -1;
+
+ breakinfo[idx].enabled = 0;
+ return 0;
+}
+
+int kgdb_set_hw_break(unsigned long addr, int type)
+{
+ int i, idx = -1;
+ for (i = 0; i < 4; i ++) {
+ if (!breakinfo[i].enabled) {
+ idx = i;
+ break;
+ }
+ }
+ if (idx == -1)
+ return -1;
+
+ breakinfo[idx].enabled = 1;
+ breakinfo[idx].type = type;
+ breakinfo[idx].len = 1;
+ breakinfo[idx].addr = addr;
+ return 0;
+}
+
+int remove_hw_break(unsigned breakno)
+{
+ if (!breakinfo[breakno].enabled) {
+ return -1;
+ }
+ breakinfo[breakno].enabled = 0;
+ return 0;
+}
+
+int set_hw_break(unsigned breakno,
+ unsigned type, unsigned len, unsigned addr)
+{
+ if (breakinfo[breakno].enabled) {
+ return -1;
+ }
+ breakinfo[breakno].enabled = 1;
+ breakinfo[breakno].type = type;
+ breakinfo[breakno].len = len;
+ breakinfo[breakno].addr = addr;
+ return 0;
+}
+
+void kgdb_printexceptioninfo(int exceptionNo, int errorcode, char *buffer)
+{
+ unsigned long dr6;
+ int i;
+ switch (exceptionNo) {
+ case 1: /* debug exception */
+ break;
+ case 3: /* breakpoint */
+ sprintf(buffer, "Software breakpoint");
+ return;
+ default:
+ sprintf(buffer, "Details not available");
+ return;
+ }
+ asm volatile ("movq %%db6, %0\n":"=r" (dr6)
+ :);
+ if (dr6 & 0x4000) {
+ sprintf(buffer, "Single step");
+ return;
+ }
+ for (i = 0; i < 4; ++i) {
+ if (dr6 & (1 << i)) {
+ sprintf(buffer, "Hardware breakpoint %d", i);
+ return;
+ }
+ }
+ sprintf(buffer, "Unknown trap");
+ return;
+}
+
+void kgdb_disable_hw_debug(struct pt_regs *regs)
+{
+ /* Disable hardware debugging while we are in kgdb */
+ asm volatile("movq %0,%%db7": /* no output */ : "r"(0UL));
+}
+
+void kgdb_post_master_code(struct pt_regs *regs, int eVector, int err_code)
+{
+ /* Master processor is completely in the debugger */
+ gdb_x86_64vector = eVector;
+ gdb_x86_64errcode = err_code;
+}
+
+int kgdb_arch_handle_exception(int exceptionVector, int signo, int err_code,
+ char *remcomInBuffer, char *remcomOutBuffer,
+ struct pt_regs *linux_regs)
+{
+ unsigned long addr, length;
+ unsigned long breakno, breaktype;
+ char *ptr;
+ int newPC;
+ unsigned long dr6;
+
+ switch (remcomInBuffer[0]) {
+ case 'c':
+ case 's':
+ if (kgdb_contthread && kgdb_contthread != current) {
+ strcpy(remcomOutBuffer, "E00");
+ break;
+ }
+
+ kgdb_contthread = NULL;
+
+ /* try to read optional parameter, pc unchanged if no parm */
+ ptr = &remcomInBuffer[1];
+ if (kgdb_hex2long(&ptr, &addr)) {
+ linux_regs->rip = addr;
+ }
+ newPC = linux_regs->rip;
+
+ /* clear the trace bit */
+ linux_regs->eflags &= 0xfffffeff;
+
+ /* set the trace bit if we're stepping */
+ if (remcomInBuffer[0] == 's') {
+ linux_regs->eflags |= 0x100;
+ debugger_step = 1;
+ }
+
+ asm volatile ("movq %%db6, %0\n" : "=r" (dr6));
+ if (!(dr6 & 0x4000)) {
+ for (breakno = 0; breakno < 4; ++breakno) {
+ if (dr6 & (1 << breakno)) {
+ if (breakinfo[breakno].type == 0) {
+ /* Set restore flag */
+ linux_regs->eflags |= 0x10000;
+ break;
+ }
+ }
+ }
+ }
+ kgdb_correct_hw_break();
+ asm volatile ("movq %0, %%db6\n"::"r" (0UL));
+
+ return (0);
+
+ case 'Y':
+ ptr = &remcomInBuffer[1];
+ kgdb_hex2long(&ptr, &breakno);
+ ptr++;
+ kgdb_hex2long(&ptr, &breaktype);
+ ptr++;
+ kgdb_hex2long(&ptr, &length);
+ ptr++;
+ kgdb_hex2long(&ptr, &addr);
+ if (set_hw_break(breakno & 0x3, breaktype & 0x3,
+ length & 0x3, addr) == 0) {
+ strcpy(remcomOutBuffer, "OK");
+ } else {
+ strcpy(remcomOutBuffer, "ERROR");
+ }
+ break;
+
+ /* Remove hardware breakpoint */
+ case 'y':
+ ptr = &remcomInBuffer[1];
+ kgdb_hex2long(&ptr, &breakno);
+ if (remove_hw_break(breakno & 0x3) == 0) {
+ strcpy(remcomOutBuffer, "OK");
+ } else {
+ strcpy(remcomOutBuffer, "ERROR");
+ }
+ break;
+
+ } /* switch */
+ return -1; /* this means that we do not want to exit from the handler */
+}
+
+static struct pt_regs *in_interrupt_stack(unsigned long rsp, int cpu)
+{
+ struct pt_regs *regs;
+ unsigned long end = (unsigned long) cpu_pda[cpu].irqstackptr;
+ if (rsp <= end &&
+ rsp >= end - IRQSTACKSIZE + 8) {
+ regs = *(((struct pt_regs **)end) -1);
+ return regs;
+ }
+ return NULL;
+}
+
+static struct pt_regs *in_exception_stack(unsigned long rsp, int cpu)
+{
+ int i;
+ for (i = 0; i < N_EXCEPTION_STACKS; i++)
+ if (rsp >= init_tss[cpu].ist[i] &&
+ rsp <= init_tss[cpu].ist[i] + EXCEPTION_STKSZ) {
+ struct pt_regs *r = (void *)init_tss[cpu].ist[i] + EXCEPTION_STKSZ;
+ return r-1;
+ }
+ return NULL;
+}
+
+static void kgdb_shadowinfo(struct pt_regs *regs, char *buffer,
+ unsigned threadid)
+{
+ static char intr_desc[] = "Stack at interrupt entrypoint";
+ static char exc_desc[] = "Stack at exception entrypoint";
+ struct pt_regs *stregs;
+ int cpu = hard_smp_processor_id();
+
+ if ((stregs = in_interrupt_stack(regs->rsp, cpu))) {
+ kgdb_mem2hex(intr_desc, buffer, strlen(intr_desc), 0);
+ } else if ((stregs = in_exception_stack(regs->rsp, cpu))) {
+ kgdb_mem2hex(exc_desc, buffer, strlen(exc_desc), 0);
+ }
+}
+
+static struct task_struct *kgdb_get_shadow_thread(struct pt_regs *regs,
+ int threadid)
+{
+ struct pt_regs *stregs;
+ int cpu = hard_smp_processor_id();
+
+ if ((stregs = in_interrupt_stack(regs->rsp, cpu))) {
+ return current;
+ } else if ((stregs = in_exception_stack(regs->rsp, cpu))) {
+ return current;
+ }
+ return NULL;
+}
+
+static struct pt_regs *kgdb_shadow_regs(struct pt_regs *regs, int threadid)
+{
+ struct pt_regs *stregs;
+ int cpu = hard_smp_processor_id();
+
+ if ((stregs = in_interrupt_stack(regs->rsp, cpu))) {
+ return stregs;
+ } else if ((stregs = in_exception_stack(regs->rsp, cpu))) {
+ return stregs;
+ }
+ return NULL;
+}
+
+/* Register KGDB with the die_chain so that we hook into all of the right
+ * spots. */
+static int kgdb_notify(struct notifier_block *self, unsigned long cmd,
+ void *ptr)
+{
+ struct die_args *d = ptr;
+
+ if (!kgdb_connected || (cmd == DIE_DEBUG && user_mode(d->regs)))
+ return NOTIFY_DONE;
+ if (cmd == DIE_NMI_IPI) {
+ if (atomic_read(debugger_active))
+ return NOTIFY_BAD;
+ } else if ((*linux_debug_hook)(d->trapnr, d->signr, d->err, d->regs))
+ return NOTIFY_BAD; /* skip */
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block kgdb_notifier = {
+ .notifier_call = kgdb_notify,
+};
+
+int kgdb_arch_init(void)
+{
+ notifier_chain_register(&die_chain, &kgdb_notifier);
+}
+
+struct kgdb_arch arch_kgdb_ops = {
+ .gdb_bpt_instr = {0xcc},
+ .flags = KGDB_HW_BREAKPOINT,
+ .shadowth = 1,
+};
--- linux-2.6.3-rc4/arch/x86_64/mm/fault.c 2004-02-17 09:50:05.000000000 -0700
+++ linux-2.6.3-rc4-kgdb/arch/x86_64/mm/fault.c 2004-02-17 11:33:47.025484956 -0700
@@ -23,6 +23,7 @@
#include <linux/vt_kern.h> /* For unblank_screen() */
#include <linux/compiler.h>
#include <linux/module.h>
+#include <linux/debugger.h>
#include <asm/system.h>
#include <asm/uaccess.h>
@@ -290,6 +291,11 @@ asmlinkage void do_page_fault(struct pt_
return;
again:
+ if (debugger_memerr_expected) {
+ /* This fault was caused by memory access through a debugger.
+ * Don't handle it like user accesses */
+ goto no_context;
+ }
down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
--- linux-2.6.3-rc4/include/asm-x86_64/kgdb.h 1969-12-31 17:00:00.000000000 -0700
+++ linux-2.6.3-rc4-kgdb/include/asm-x86_64/kgdb.h 2004-02-17 11:34:07.822764827 -0700
@@ -0,0 +1,57 @@
+#ifndef _ASM_KGDB_H_
+#define _ASM_KGDB_H_
+
+/*
+ * Copyright (C) 2001-2004 Amit S. Kale
+ */
+
+#include <linux/ptrace.h>
+
+/* gdb locks */
+#define KGDB_MAX_NO_CPUS 8
+
+/************************************************************************/
+/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/
+/* at least NUMREGBYTES*2 are needed for register packets */
+/* Longer buffer is needed to list all threads */
+#define BUFMAX 1024
+
+/*
+ * Note that this register image is in a different order than
+ * the register image that Linux produces at interrupt time.
+ *
+ * Linux's register image is defined by struct pt_regs in ptrace.h.
+ * Just why GDB uses a different order is a historical mystery.
+ */
+
+enum regnames {_RAX,
+ _RDX,
+ _RCX,
+ _RBX,
+ _RSI,
+ _RDI,
+ _RBP,
+ _RSP,
+ _R8,
+ _R9,
+ _R10,
+ _R11,
+ _R12,
+ _R13,
+ _R14,
+ _R15,
+ _PC,
+ _PS,
+ _LASTREG=_PS };
+
+#define PC_REGNUM _PC /* Program Counter */
+#define SP_REGNUM _RSP /* Stack Pointer */
+#define PTRACE_PC rip /* Program Counter, in ptrace regs. */
+
+/* Number of bytes of registers. */
+#define NUMREGBYTES (_LASTREG*8)
+
+#define BREAKPOINT() asm(" int $3");
+#define BREAK_INSTR_SIZE 1
+
+#endif /* _ASM_KGDB_H_ */
--- linux-2.6.3-rc4/include/asm-x86_64/processor.h 2004-02-17 09:54:25.000000000 -0700
+++ linux-2.6.3-rc4-kgdb/include/asm-x86_64/processor.h 2004-02-17 11:34:27.054400086 -0700
@@ -252,6 +252,7 @@ struct thread_struct {
unsigned long *io_bitmap_ptr;
/* cached TLS descriptors. */
u64 tls_array[GDT_ENTRY_TLS_ENTRIES];
+ void *debuggerinfo;
};
#define INIT_THREAD {}
--- linux-2.6.3-rc4/include/asm-x86_64/system.h 2004-02-17 09:53:49.000000000 -0700
+++ linux-2.6.3-rc4-kgdb/include/asm-x86_64/system.h 2004-02-17 11:34:20.762827993 -0700
@@ -19,6 +19,56 @@
#define __SAVE(reg,offset) "movq %%" #reg ",(14-" #offset ")*8(%%rsp)\n\t"
#define __RESTORE(reg,offset) "movq (14-" #offset ")*8(%%rsp),%%" #reg "\n\t"
+/* #ifdef CONFIG_KGDB */
+
+/* full frame for the debug stub */
+/* Should be replaced with a dwarf2 cie/fde description, then gdb could
+ figure it out all by itself. */
+struct save_context_frame {
+ unsigned long rbp;
+ unsigned long rbx;
+ unsigned long r11;
+ unsigned long r10;
+ unsigned long r9;
+ unsigned long r8;
+ unsigned long rcx;
+ unsigned long rdx;
+ unsigned long r15;
+ unsigned long r14;
+ unsigned long r13;
+ unsigned long r12;
+ unsigned long rdi;
+ unsigned long rsi;
+ unsigned long flags;
+};
+
+#if 0
+#define SAVE_CONTEXT \
+ "pushfq\n\t" \
+ "subq $14*8,%%rsp\n\t" \
+ __SAVE(rbx, 12) __SAVE(rdi, 1) \
+ __SAVE(rdx, 6) __SAVE(rcx, 7) \
+ __SAVE(r8, 8) __SAVE(r9, 9) \
+ __SAVE(r12, 2) __SAVE(r13, 3) \
+ __SAVE(r14, 4) __SAVE(r15, 5) \
+ __SAVE(r10, 10) __SAVE(r11, 11) \
+ __SAVE(rsi, 0) __SAVE(rbp, 13) \
+
+
+#define RESTORE_CONTEXT \
+ __RESTORE(rbx, 12) __RESTORE(rdi, 1) \
+ __RESTORE(rdx, 6) __RESTORE(rcx, 7) \
+ __RESTORE(r12, 2) __RESTORE(r13, 3) \
+ __RESTORE(r14, 4) __RESTORE(r15, 5) \
+ __RESTORE(r10, 10) __RESTORE(r11, 11) \
+ __RESTORE(r8, 8) __RESTORE(r9, 9) \
+ __RESTORE(rbp, 13) __RESTORE(rsi, 0) \
+ "addq $14*8,%%rsp\n\t" \
+ "popfq\n\t"
+
+#define __EXTRA_CLOBBER
+
+#else
/* frame pointer must be last for get_wchan */
#define SAVE_CONTEXT "pushfq ; pushq %%rbp ; movq %%rsi,%%rbp\n\t"
#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popfq\n\t"
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH][6/6] A different KGDB stub
@ 2004-02-12 0:04 Tom Rini
0 siblings, 0 replies; 10+ messages in thread
From: Tom Rini @ 2004-02-12 0:04 UTC (permalink / raw)
To: Andrew Morton, Kernel Mailing List
The following is the x86_64-specific bits to this KGDB stub.
arch/x86_64/Kconfig | 5
arch/x86_64/kernel/Makefile | 1
arch/x86_64/kernel/entry.S | 41 ++-
arch/x86_64/kernel/irq.c | 2
arch/x86_64/kernel/nmi.c | 16 +
arch/x86_64/kernel/traps.c | 6
arch/x86_64/kernel/x86_64-stub.c | 523 +++++++++++++++++++++++++++++++++++++++
arch/x86_64/mm/fault.c | 8
include/asm-x86_64/dwarf2.h | 2
include/asm-x86_64/kgdb.h | 57 ++++
include/asm-x86_64/processor.h | 1
include/asm-x86_64/system.h | 50 +++
12 files changed, 703 insertions(+), 9 deletions(-)
--- a/arch/x86_64/Kconfig Wed Feb 11 15:42:06 2004
+++ b/arch/x86_64/Kconfig Wed Feb 11 15:42:06 2004
@@ -463,10 +463,7 @@
Add a simple leak tracer to the IOMMU code. This is useful when you
are debugging a buggy device driver that leaks IOMMU mappings.
-#config X86_REMOTE_DEBUG
-# bool "kgdb debugging stub"
-
-endmenu
+source "kernel/Kconfig.kgdb"
source "security/Kconfig"
--- a/arch/x86_64/kernel/Makefile Wed Feb 11 15:42:06 2004
+++ b/arch/x86_64/kernel/Makefile Wed Feb 11 15:42:06 2004
@@ -24,6 +24,7 @@
obj-$(CONFIG_DUMMY_IOMMU) += pci-nommu.o pci-dma.o
obj-$(CONFIG_MODULES) += module.o
+obj-$(CONFIG_KGDB) += x86_64-stub.o
obj-y += topology.o
--- a/arch/x86_64/kernel/entry.S Wed Feb 11 15:42:06 2004
+++ b/arch/x86_64/kernel/entry.S Wed Feb 11 15:42:06 2004
@@ -219,7 +219,7 @@
jnc sysret_signal
sti
pushq %rdi
- call schedule
+ call user_schedule
popq %rdi
jmp sysret_check
@@ -288,7 +288,7 @@
jnc int_very_careful
sti
pushq %rdi
- call schedule
+ call user_schedule
popq %rdi
jmp int_with_check
@@ -482,7 +482,7 @@
jnc retint_signal
sti
pushq %rdi
- call schedule
+ call user_schedule
popq %rdi
GET_THREAD_INFO(%rcx)
cli
@@ -868,3 +868,38 @@
ENTRY(call_debug)
zeroentry do_call_debug
+#ifdef CONFIG_KGDB_THREAD
+ENTRY(kern_schedule)
+ subq $21*8,%rsp
+ movq %rax,10*8(%rsp)
+
+ movq %rsp,%rax
+ addq $21*8,%rax
+ movq %rax, 19*8(%rsp)
+
+ pushfq
+ popq 18*8(%rsp)
+
+ movq 21*8(%rsp),%rax
+ movq %rax,16*8(%rsp)
+
+ movq %rdi,14*8(%rsp)
+ movq %rsi,13*8(%rsp)
+ movq %rdx,12*8(%rsp)
+ movq %rcx,11*8(%rsp)
+
+ movq %r8, 9*8(%rsp)
+ movq %r9, 8*8(%rsp)
+ movq %r10,7*8(%rsp)
+ movq %r11,6*8(%rsp)
+ movq %rbx,5*8(%rsp)
+ movq %rbp,4*8(%rsp)
+ movq %r12,3*8(%rsp)
+ movq %r13,2*8(%rsp)
+ movq %r14,1*8(%rsp)
+ movq %r15,(%rsp)
+ call kern_do_schedule
+ movq 10*8(%rsp), %rax
+ addq $21*8,%rsp
+ ret
+#endif
--- a/arch/x86_64/kernel/irq.c Wed Feb 11 15:42:06 2004
+++ b/arch/x86_64/kernel/irq.c Wed Feb 11 15:42:06 2004
@@ -405,6 +405,8 @@
spin_unlock(&desc->lock);
irq_exit();
+
+ kgdb_process_breakpoint();
return 1;
}
--- a/arch/x86_64/kernel/nmi.c Wed Feb 11 15:42:06 2004
+++ b/arch/x86_64/kernel/nmi.c Wed Feb 11 15:42:06 2004
@@ -24,6 +24,7 @@
#include <linux/module.h>
#include <linux/sysdev.h>
#include <linux/nmi.h>
+#include <linux/debugger.h>
#include <asm/smp.h>
#include <asm/mtrr.h>
@@ -317,13 +318,26 @@
return;
sum = read_pda(apic_timer_irqs);
- if (last_irq_sums[cpu] == sum) {
+ if (atomic_read(&debugger_active)) {
+
+ /*
+ * The machine is in debugger, hold this cpu if already
+ * not held.
+ */
+ debugger_nmihook(cpu, regs);
+ alert_counter[cpu] = 0;
+
+ } else if (last_irq_sums[cpu] == sum) {
+
/*
* Ayiee, looks like this CPU is stuck ...
* wait a few IRQs (5 seconds) before doing the oops ...
*/
alert_counter[cpu]++;
if (alert_counter[cpu] == 5*nmi_hz) {
+
+ CHK_DEBUGGER(2,SIGSEGV,0,regs,)
+
if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_BAD) {
alert_counter[cpu] = 0;
return;
--- a/arch/x86_64/kernel/traps.c Wed Feb 11 15:42:06 2004
+++ b/arch/x86_64/kernel/traps.c Wed Feb 11 15:42:06 2004
@@ -28,6 +28,7 @@
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/debugger.h>
#include <asm/system.h>
#include <asm/uaccess.h>
@@ -363,6 +364,7 @@
void die(const char * str, struct pt_regs * regs, long err)
{
+ CHK_DEBUGGER(1,SIGTRAP,err,regs,)
oops_begin();
handle_BUG(regs);
__die(str, regs, err);
@@ -436,6 +438,7 @@
#define DO_ERROR(trapnr, signr, str, name) \
asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
{ \
+ CHK_DEBUGGER(1,SIGTRAP,error_code,regs,return) \
if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) == NOTIFY_BAD) \
return; \
do_trap(trapnr, signr, str, regs, error_code, NULL); \
@@ -614,7 +617,7 @@
tsk->thread.debugreg6 = condition;
/* Mask out spurious TF errors due to lazy TF clearing */
- if (condition & DR_STEP) {
+ if (condition & DR_STEP && !debugger_step) {
/*
* The TF error should be masked out only if the current
* process is not traced and if the TRAP flag has been set
@@ -643,6 +646,7 @@
force_sig_info(SIGTRAP, &info, tsk);
clear_dr7:
asm volatile("movq %0,%%db7"::"r"(0UL));
+ CHK_DEBUGGER(1,SIGTRAP,error_code,regs,return)
notify_die(DIE_DEBUG, "debug", regs, error_code, 1, SIGTRAP);
return;
--- /dev/null Wed Dec 31 16:00:00 1969
+++ b/arch/x86_64/kernel/x86_64-stub.c Wed Feb 11 15:42:06 2004
@@ -0,0 +1,523 @@
+/*
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ */
+
+/*
+ * Copyright (C) 2004 Amit S. Kale
+ * Copyright (C) 2000-2001 VERITAS Software Corporation.
+ * Copyright (C) 2002 Andi Kleen, SuSE Labs
+ */
+/****************************************************************************
+ * Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $
+ *
+ * Module name: remcom.c $
+ * Revision: 1.34 $
+ * Date: 91/03/09 12:29:49 $
+ * Contributor: Lake Stevens Instrument Division$
+ *
+ * Description: low level support for gdb debugger. $
+ *
+ * Considerations: only works on target hardware $
+ *
+ * Written by: Glenn Engel $
+ * Updated by: Amit Kale<akale@veritas.com>
+ * ModuleState: Experimental $
+ *
+ * NOTES: See Below $
+ *
+ * Modified for 386 by Jim Kingdon, Cygnus Support.
+ * Origianl kgdb, compatibility with 2.1.xx kernel by David Grothe <dave@gcom.com>
+ * Integrated into 2.2.5 kernel by Tigran Aivazian <tigran@sco.com>
+ * thread support,
+ * support for multiple processors,
+ * support for ia-32(x86) hardware debugging,
+ * Console support,
+ * handling nmi watchdog
+ * Amit S. Kale ( amitkale@emsyssoft.com )
+ *
+ * X86_64 changes from Andi Kleen's patch merged by Jim Houston
+ *
+ *
+ * To enable debugger support, two things need to happen. One, a
+ * call to set_debug_traps() is necessary in order to allow any breakpoints
+ * or error conditions to be properly intercepted and reported to gdb.
+ * Two, a breakpoint needs to be generated to begin communication. This
+ * is most easily accomplished by a call to breakpoint(). Breakpoint()
+ * simulates a breakpoint by executing an int 3.
+ *
+ *************
+ *
+ * The following gdb commands are supported:
+ *
+ * command function Return value
+ *
+ * g return the value of the CPU registers hex data or ENN
+ * G set the value of the CPU registers OK or ENN
+ *
+ * mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN
+ * MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN
+ *
+ * c Resume at current address SNN ( signal NN)
+ * cAA..AA Continue at address AA..AA SNN
+ *
+ * s Step one instruction SNN
+ * sAA..AA Step one instruction from AA..AA SNN
+ *
+ * k kill
+ *
+ * ? What was the last sigval ? SNN (signal NN)
+ *
+ * All commands and responses are sent with a packet which includes a
+ * checksum. A packet consists of
+ *
+ * $<packet info>#<checksum>.
+ *
+ * where
+ * <packet info> :: <characters representing the command or response>
+ * <checksum> :: < two hex digits computed as modulo 256 sum of <packetinfo>>
+ *
+ * When a packet is received, it is first acknowledged with either '+' or '-'.
+ * '+' indicates a successful transfer. '-' indicates a failed transfer.
+ *
+ * Example:
+ *
+ * Host: Reply:
+ * $m0,10#2a +$00010203040506070809101112131415#42
+ *
+ ****************************************************************************/
+
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <asm/system.h>
+#include <asm/ptrace.h> /* for linux pt_regs struct */
+#include <linux/kgdb.h>
+#ifdef CONFIG_GDB_CONSOLE
+#include <linux/console.h>
+#endif
+#include <linux/init.h>
+#include <linux/debugger.h>
+
+/* Put the error code here just in case the user cares. */
+int gdb_x86_64errcode;
+/* Likewise, the vector number here (since GDB only gets the signal
+ number through the usual means, and that's not very specific). */
+int gdb_x86_64vector = -1;
+
+#if KGDB_MAX_NO_CPUS != 8
+#error change the definition of slavecpulocks
+#endif
+
+void regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+ gdb_regs[_RAX] = regs->rax;
+ gdb_regs[_RBX] = regs->rbx;
+ gdb_regs[_RCX] = regs->rcx;
+ gdb_regs[_RDX] = regs->rdx;
+ gdb_regs[_RSI] = regs->rsi;
+ gdb_regs[_RDI] = regs->rdi;
+ gdb_regs[_RBP] = regs->rbp;
+ gdb_regs[ _PS] = regs->eflags;
+ gdb_regs[ _PC] = regs->rip;
+ gdb_regs[ _R8] = regs->r8;
+ gdb_regs[ _R9] = regs->r9;
+ gdb_regs[_R10] = regs->r10;
+ gdb_regs[_R11] = regs->r11;
+ gdb_regs[_R12] = regs->r12;
+ gdb_regs[_R13] = regs->r13;
+ gdb_regs[_R14] = regs->r14;
+ gdb_regs[_R15] = regs->r15;
+ gdb_regs[_RSP] = regs->rsp;
+}
+
+struct task_struct *__switch_to(struct task_struct *prev_p,
+ struct task_struct *next_p);
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
+{
+ gdb_regs[_RAX] = 0;
+ gdb_regs[_RBX] = 0;
+ gdb_regs[_RCX] = 0;
+ gdb_regs[_RDX] = 0;
+ gdb_regs[_RSI] = 0;
+ gdb_regs[_RDI] = 0;
+ gdb_regs[_RBP] = 0;
+ gdb_regs[ _PS] = 0;
+ gdb_regs[ _PC] = (unsigned long) __switch_to;
+ gdb_regs[ _R8] = 0;
+ gdb_regs[ _R9] = 0;
+ gdb_regs[_R10] = 0;
+ gdb_regs[_R11] = 0;
+ gdb_regs[_R12] = 0;
+ gdb_regs[_R13] = 0;
+ gdb_regs[_R14] = 0;
+ gdb_regs[_R15] = 0;
+ gdb_regs[_RSP] = p->thread.rsp;
+}
+
+void gdb_regs_to_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+ regs->rax = gdb_regs[_RAX] ;
+ regs->rbx = gdb_regs[_RBX] ;
+ regs->rcx = gdb_regs[_RCX] ;
+ regs->rdx = gdb_regs[_RDX] ;
+ regs->rsi = gdb_regs[_RSI] ;
+ regs->rdi = gdb_regs[_RDI] ;
+ regs->rbp = gdb_regs[_RBP] ;
+ regs->eflags= gdb_regs[ _PS] ;
+ regs->rip = gdb_regs[ _PC] ;
+ regs->r8 = gdb_regs[ _R8] ;
+ regs->r9 = gdb_regs[ _R9] ;
+ regs->r10 = gdb_regs[ _R10] ;
+ regs->r11 = gdb_regs[ _R11] ;
+ regs->r12 = gdb_regs[ _R12] ;
+ regs->r13 = gdb_regs[ _R13] ;
+ regs->r14 = gdb_regs[ _R14] ;
+ regs->r15 = gdb_regs[ _R15] ;
+#if 0 /* can't change these */
+ regs->rsp = gdb_regs[_RSP] ;
+ regs->ss = gdb_regs[ _SS] ;
+ regs->fs = gdb_regs[ _FS] ;
+ regs->gs = gdb_regs[ _GS] ;
+#endif
+
+} /* gdb_regs_to_regs */
+
+
+struct hw_breakpoint {
+ unsigned enabled;
+ unsigned type;
+ unsigned len;
+ unsigned long addr;
+} breakinfo[4] = { {
+enabled:0}, {
+enabled:0}, {
+enabled:0}, {
+enabled:0}};
+
+void kgdb_correct_hw_break(void)
+{
+ int breakno;
+ int correctit;
+ int breakbit;
+ unsigned long dr7;
+
+ asm volatile ("movq %%db7, %0\n":"=r" (dr7) :);
+ do {
+ unsigned long addr0, addr1, addr2, addr3;
+ asm volatile ("movq %%db0, %0\n"
+ "movq %%db1, %1\n"
+ "movq %%db2, %2\n"
+ "movq %%db3, %3\n":"=r" (addr0), "=r"(addr1),
+ "=r"(addr2), "=r"(addr3):);
+ } while (0);
+ correctit = 0;
+ for (breakno = 0; breakno < 3; breakno++) {
+ breakbit = 2 << (breakno << 1);
+ if (!(dr7 & breakbit) && breakinfo[breakno].enabled) {
+ correctit = 1;
+ dr7 |= breakbit;
+ dr7 &= ~(0xf0000 << (breakno << 2));
+ dr7 |= (((breakinfo[breakno].len << 2) |
+ breakinfo[breakno].type) << 16) <<
+ (breakno << 2);
+ switch (breakno) {
+ case 0:
+ asm volatile ("movq %0, %%dr0\n"::"r"
+ (breakinfo[breakno].addr));
+ break;
+
+ case 1:
+ asm volatile ("movq %0, %%dr1\n"::"r"
+ (breakinfo[breakno].addr));
+ break;
+
+ case 2:
+ asm volatile ("movq %0, %%dr2\n"::"r"
+ (breakinfo[breakno].addr));
+ break;
+
+ case 3:
+ asm volatile ("movq %0, %%dr3\n"::"r"
+ (breakinfo[breakno].addr));
+ break;
+ }
+ } else if ((dr7 & breakbit) && !breakinfo[breakno].enabled) {
+ correctit = 1;
+ dr7 &= ~breakbit;
+ dr7 &= ~(0xf0000 << (breakno << 2));
+ }
+ }
+ if (correctit) {
+ asm volatile ("movq %0, %%db7\n"::"r" (dr7));
+ }
+}
+
+int kgdb_remove_hw_break(unsigned long addr, int type)
+{
+ int i, idx = -1;
+ for (i = 0; i < 4; i ++) {
+ if (breakinfo[i].addr == addr && breakinfo[i].enabled) {
+ idx = i;
+ break;
+ }
+ }
+ if (idx == -1)
+ return -1;
+
+ breakinfo[idx].enabled = 0;
+ return 0;
+}
+
+int kgdb_set_hw_break(unsigned long addr, int type)
+{
+ int i, idx = -1;
+ for (i = 0; i < 4; i ++) {
+ if (!breakinfo[i].enabled) {
+ idx = i;
+ break;
+ }
+ }
+ if (idx == -1)
+ return -1;
+
+ breakinfo[idx].enabled = 1;
+ breakinfo[idx].type = type;
+ breakinfo[idx].len = 1;
+ breakinfo[idx].addr = addr;
+ return 0;
+}
+
+int remove_hw_break(unsigned breakno)
+{
+ if (!breakinfo[breakno].enabled) {
+ return -1;
+ }
+ breakinfo[breakno].enabled = 0;
+ return 0;
+}
+
+int set_hw_break(unsigned breakno,
+ unsigned type, unsigned len, unsigned addr)
+{
+ if (breakinfo[breakno].enabled) {
+ return -1;
+ }
+ breakinfo[breakno].enabled = 1;
+ breakinfo[breakno].type = type;
+ breakinfo[breakno].len = len;
+ breakinfo[breakno].addr = addr;
+ return 0;
+}
+
+void kgdb_printexceptioninfo(int exceptionNo, int errorcode, char *buffer)
+{
+ unsigned long dr6;
+ int i;
+ switch (exceptionNo) {
+ case 1: /* debug exception */
+ break;
+ case 3: /* breakpoint */
+ sprintf(buffer, "Software breakpoint");
+ return;
+ default:
+ sprintf(buffer, "Details not available");
+ return;
+ }
+ asm volatile ("movq %%db6, %0\n":"=r" (dr6)
+ :);
+ if (dr6 & 0x4000) {
+ sprintf(buffer, "Single step");
+ return;
+ }
+ for (i = 0; i < 4; ++i) {
+ if (dr6 & (1 << i)) {
+ sprintf(buffer, "Hardware breakpoint %d", i);
+ return;
+ }
+ }
+ sprintf(buffer, "Unknown trap");
+ return;
+}
+
+void kgdb_disable_hw_debug(struct pt_regs *regs)
+{
+ /* Disable hardware debugging while we are in kgdb */
+ asm volatile("movq %0,%%db7": /* no output */ : "r"(0UL));
+}
+
+void kgdb_post_master_code(struct pt_regs *regs, int eVector, int err_code)
+{
+ /* Master processor is completely in the debugger */
+ gdb_x86_64vector = eVector;
+ gdb_x86_64errcode = err_code;
+}
+
+int kgdb_arch_handle_exception(int exceptionVector, int signo, int err_code,
+ char *remcomInBuffer, char *remcomOutBuffer,
+ struct pt_regs *linux_regs)
+{
+ unsigned long addr, length;
+ unsigned long breakno, breaktype;
+ char *ptr;
+ int newPC;
+ unsigned long dr6;
+
+ switch (remcomInBuffer[0]) {
+ case 'c':
+ case 's':
+ if (kgdb_contthread && kgdb_contthread != current) {
+ strcpy(remcomOutBuffer, "E00");
+ break;
+ }
+
+ kgdb_contthread = NULL;
+
+ /* try to read optional parameter, pc unchanged if no parm */
+ ptr = &remcomInBuffer[1];
+ if (kgdb_hexToLong(&ptr, &addr)) {
+ linux_regs->rip = addr;
+ }
+ newPC = linux_regs->rip;
+
+ /* clear the trace bit */
+ linux_regs->eflags &= 0xfffffeff;
+
+ /* set the trace bit if we're stepping */
+ if (remcomInBuffer[0] == 's') {
+ linux_regs->eflags |= 0x100;
+ debugger_step = 1;
+ }
+
+ asm volatile ("movq %%db6, %0\n" : "=r" (dr6));
+ if (!(dr6 & 0x4000)) {
+ for (breakno = 0; breakno < 4; ++breakno) {
+ if (dr6 & (1 << breakno)) {
+ if (breakinfo[breakno].type == 0) {
+ /* Set restore flag */
+ linux_regs->eflags |= 0x10000;
+ break;
+ }
+ }
+ }
+ }
+ kgdb_correct_hw_break();
+ asm volatile ("movq %0, %%db6\n"::"r" (0UL));
+
+ return (0);
+
+ case 'Y':
+ ptr = &remcomInBuffer[1];
+ kgdb_hexToLong(&ptr, &breakno);
+ ptr++;
+ kgdb_hexToLong(&ptr, &breaktype);
+ ptr++;
+ kgdb_hexToLong(&ptr, &length);
+ ptr++;
+ kgdb_hexToLong(&ptr, &addr);
+ if (set_hw_break(breakno & 0x3, breaktype & 0x3,
+ length & 0x3, addr) == 0) {
+ strcpy(remcomOutBuffer, "OK");
+ } else {
+ strcpy(remcomOutBuffer, "ERROR");
+ }
+ break;
+
+ /* Remove hardware breakpoint */
+ case 'y':
+ ptr = &remcomInBuffer[1];
+ kgdb_hexToLong(&ptr, &breakno);
+ if (remove_hw_break(breakno & 0x3) == 0) {
+ strcpy(remcomOutBuffer, "OK");
+ } else {
+ strcpy(remcomOutBuffer, "ERROR");
+ }
+ break;
+
+ } /* switch */
+ return -1; /* this means that we do not want to exit from the handler */
+}
+
+static struct pt_regs *in_interrupt_stack(unsigned long rsp, int cpu)
+{
+ struct pt_regs *regs;
+ unsigned long end = (unsigned long) cpu_pda[cpu].irqstackptr;
+ if (rsp <= end &&
+ rsp >= end - IRQSTACKSIZE + 8) {
+ regs = *(((struct pt_regs **)end) -1);
+ return regs;
+ }
+ return NULL;
+}
+
+static struct pt_regs *in_exception_stack(unsigned long rsp, int cpu)
+{
+ int i;
+ for (i = 0; i < N_EXCEPTION_STACKS; i++)
+ if (rsp >= init_tss[cpu].ist[i] &&
+ rsp <= init_tss[cpu].ist[i] + EXCEPTION_STKSZ) {
+ struct pt_regs *r = (void *)init_tss[cpu].ist[i] + EXCEPTION_STKSZ;
+ return r-1;
+ }
+ return NULL;
+}
+
+static void kgdb_shadowinfo(struct pt_regs *regs, char *buffer,
+ unsigned threadid)
+{
+ static char intr_desc[] = "Stack at interrupt entrypoint";
+ static char exc_desc[] = "Stack at exception entrypoint";
+ struct pt_regs *stregs;
+ int cpu = hard_smp_processor_id();
+
+ if ((stregs = in_interrupt_stack(regs->rsp, cpu))) {
+ kgdb_mem2hex(intr_desc, buffer, strlen(intr_desc), 0);
+ } else if ((stregs = in_exception_stack(regs->rsp, cpu))) {
+ kgdb_mem2hex(exc_desc, buffer, strlen(exc_desc), 0);
+ }
+}
+
+static struct task_struct *kgdb_get_shadow_thread(struct pt_regs *regs,
+ int threadid)
+{
+ struct pt_regs *stregs;
+ int cpu = hard_smp_processor_id();
+
+ if ((stregs = in_interrupt_stack(regs->rsp, cpu))) {
+ return current;
+ } else if ((stregs = in_exception_stack(regs->rsp, cpu))) {
+ return current;
+ }
+ return NULL;
+}
+
+static struct pt_regs *kgdb_shadow_regs(struct pt_regs *regs, int threadid)
+{
+ struct pt_regs *stregs;
+ int cpu = hard_smp_processor_id();
+
+ if ((stregs = in_interrupt_stack(regs->rsp, cpu))) {
+ return stregs;
+ } else if ((stregs = in_exception_stack(regs->rsp, cpu))) {
+ return stregs;
+ }
+ return NULL;
+}
+
+struct kgdb_arch arch_kgdb_ops = {
+ .gdb_bpt_instr = {0xcc},
+ .flags = KGDB_HW_BREAKPOINT,
+ .shadowth = 1,
+};
--- a/arch/x86_64/mm/fault.c Wed Feb 11 15:42:06 2004
+++ b/arch/x86_64/mm/fault.c Wed Feb 11 15:42:06 2004
@@ -23,6 +23,7 @@
#include <linux/vt_kern.h> /* For unblank_screen() */
#include <linux/compiler.h>
#include <linux/module.h>
+#include <linux/debugger.h>
#include <asm/system.h>
#include <asm/uaccess.h>
@@ -290,6 +291,11 @@
return;
again:
+ if (debugger_memerr_expected) {
+ /* This fault was caused by memory access through a debugger.
+ * Don't handle it like user accesses */
+ goto no_context;
+ }
down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
@@ -410,6 +416,8 @@
if (is_errata93(regs, address))
return;
+
+ CHK_DEBUGGER(14, SIGSEGV,error_code, regs,)
/*
* Oops. The kernel tried to access some bad page. We'll have to
--- a/include/asm-x86_64/dwarf2.h Wed Feb 11 15:42:06 2004
+++ b/include/asm-x86_64/dwarf2.h Wed Feb 11 15:42:06 2004
@@ -12,6 +12,8 @@
See "as.info" for details on these pseudo ops. Unfortunately
they are only supported in very new binutils, so define them
away for older version.
+
+ If you want to build a KGDB kernel install the new assembler.
*/
#ifdef CONFIG_DEBUG_INFO
--- /dev/null Wed Dec 31 16:00:00 1969
+++ b/include/asm-x86_64/kgdb.h Wed Feb 11 15:42:06 2004
@@ -0,0 +1,57 @@
+#ifndef _ASM_KGDB_H_
+#define _ASM_KGDB_H_
+
+/*
+ * Copyright (C) 2001-2004 Amit S. Kale
+ */
+
+#include <linux/ptrace.h>
+
+/* gdb locks */
+#define KGDB_MAX_NO_CPUS 8
+
+/************************************************************************/
+/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/
+/* at least NUMREGBYTES*2 are needed for register packets */
+/* Longer buffer is needed to list all threads */
+#define BUFMAX 1024
+
+/*
+ * Note that this register image is in a different order than
+ * the register image that Linux produces at interrupt time.
+ *
+ * Linux's register image is defined by struct pt_regs in ptrace.h.
+ * Just why GDB uses a different order is a historical mystery.
+ */
+
+enum regnames {_RAX,
+ _RDX,
+ _RCX,
+ _RBX,
+ _RSI,
+ _RDI,
+ _RBP,
+ _RSP,
+ _R8,
+ _R9,
+ _R10,
+ _R11,
+ _R12,
+ _R13,
+ _R14,
+ _R15,
+ _PC,
+ _PS,
+ _LASTREG=_PS };
+
+#define PC_REGNUM _PC /* Program Counter */
+#define SP_REGNUM _RSP /* Stack Pointer */
+#define PTRACE_PC rip /* Program Counter, in ptrace regs. */
+
+/* Number of bytes of registers. */
+#define NUMREGBYTES (_LASTREG*8)
+
+#define BREAKPOINT() asm(" int $3");
+#define BREAK_INSTR_SIZE 1
+
+#endif /* _ASM_KGDB_H_ */
--- a/include/asm-x86_64/processor.h Wed Feb 11 15:42:06 2004
+++ b/include/asm-x86_64/processor.h Wed Feb 11 15:42:06 2004
@@ -252,6 +252,7 @@
unsigned long *io_bitmap_ptr;
/* cached TLS descriptors. */
u64 tls_array[GDT_ENTRY_TLS_ENTRIES];
+ void *debuggerinfo;
};
#define INIT_THREAD {}
--- a/include/asm-x86_64/system.h Wed Feb 11 15:42:06 2004
+++ b/include/asm-x86_64/system.h Wed Feb 11 15:42:06 2004
@@ -19,6 +19,56 @@
#define __SAVE(reg,offset) "movq %%" #reg ",(14-" #offset ")*8(%%rsp)\n\t"
#define __RESTORE(reg,offset) "movq (14-" #offset ")*8(%%rsp),%%" #reg "\n\t"
+/* #ifdef CONFIG_KGDB */
+
+/* full frame for the debug stub */
+/* Should be replaced with a dwarf2 cie/fde description, then gdb could
+ figure it out all by itself. */
+struct save_context_frame {
+ unsigned long rbp;
+ unsigned long rbx;
+ unsigned long r11;
+ unsigned long r10;
+ unsigned long r9;
+ unsigned long r8;
+ unsigned long rcx;
+ unsigned long rdx;
+ unsigned long r15;
+ unsigned long r14;
+ unsigned long r13;
+ unsigned long r12;
+ unsigned long rdi;
+ unsigned long rsi;
+ unsigned long flags;
+};
+
+#if 0
+#define SAVE_CONTEXT \
+ "pushfq\n\t" \
+ "subq $14*8,%%rsp\n\t" \
+ __SAVE(rbx, 12) __SAVE(rdi, 1) \
+ __SAVE(rdx, 6) __SAVE(rcx, 7) \
+ __SAVE(r8, 8) __SAVE(r9, 9) \
+ __SAVE(r12, 2) __SAVE(r13, 3) \
+ __SAVE(r14, 4) __SAVE(r15, 5) \
+ __SAVE(r10, 10) __SAVE(r11, 11) \
+ __SAVE(rsi, 0) __SAVE(rbp, 13) \
+
+
+#define RESTORE_CONTEXT \
+ __RESTORE(rbx, 12) __RESTORE(rdi, 1) \
+ __RESTORE(rdx, 6) __RESTORE(rcx, 7) \
+ __RESTORE(r12, 2) __RESTORE(r13, 3) \
+ __RESTORE(r14, 4) __RESTORE(r15, 5) \
+ __RESTORE(r10, 10) __RESTORE(r11, 11) \
+ __RESTORE(r8, 8) __RESTORE(r9, 9) \
+ __RESTORE(rbp, 13) __RESTORE(rsi, 0) \
+ "addq $14*8,%%rsp\n\t" \
+ "popfq\n\t"
+
+#define __EXTRA_CLOBBER
+
+#else
/* frame pointer must be last for get_wchan */
#define SAVE_CONTEXT "pushfq ; pushq %%rbp ; movq %%rsi,%%rbp\n\t"
#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popfq\n\t"
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 10+ messages in thread
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[not found] <20040212000408.GG19676@smtp.west.cox.net.suse.lists.linux.kernel>
2004-02-12 6:43 ` [PATCH][6/6] A different KGDB stub Andi Kleen
2004-02-12 15:50 ` Tom Rini
2004-02-13 3:00 ` Andi Kleen
2004-02-12 16:27 ` Tom Rini
2004-02-16 19:47 ` Pavel Machek
2004-02-12 18:32 ` Tom Rini
2004-02-17 22:04 Tom Rini
[not found] ` <20040217223040.GA1560@elf.ucw.cz>
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2004-02-17 23:08 ` Pavel Machek
2004-02-17 23:13 ` Tom Rini
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2004-02-12 0:04 Tom Rini
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