Re: [Kgdb-bugreport] [PATCH][2/3] Update CVS KGDB's have kgdb_{schedule,process}_breakpoint

From: Amit S. Kale
Date: Mon Mar 01 2004 - 03:34:03 EST


On Friday 27 Feb 2004 4:49 am, George Anzinger wrote:
> Amit S. Kale wrote:
> > On Thursday 26 Feb 2004 3:13 am, Tom Rini wrote:
> >>The following adds, and then makes use of kgdb_process_breakpoint /
> >>kgdb_schedule_breakpoint. Using it i kgdb_8250.c isn't strictly needed,
> >>but it isn't wrong either.
> >
> > That makes 8250 response it a _bit_ slower. A user will notice when kgdb
> > doesn't respond within a millisecond of pressing Ctrl+C :-)
>
> Hm... I have been wondering if it might not be a good idea to put some
> comments to the user at or around the breakpoint. Possibly we might want
> to tell the user about where the info files are or some such. This would
> then come up on his screen when the source code at the breakpoint is
> displayed.

Err, well, I don't seem to understand this.

Do you mean we print a (gdb) console message that indicates something about a
breakpoint? If we do that, there has to be a way to turn it off. I have a
(rather bad) habit of stepping through kernel code :-)

What are info files?

-Amit

>
> comments...
>
> -g
>
> > OK to checkin.
> > -Amit
> >
> >># This is a BitKeeper generated patch for the following project:
> >># Project Name: Linux kernel tree
> >># This patch format is intended for GNU patch command version 2.5 or
> >>higher. # This patch includes the following deltas:
> >># ChangeSet 1.1663 -> 1.1664
> >># arch/i386/kernel/irq.c 1.48 -> 1.49
> >># drivers/net/kgdb_eth.c 1.2 -> 1.3
> >># arch/x86_64/kernel/irq.c 1.21 -> 1.22
> >># drivers/serial/kgdb_8250.c 1.3 -> 1.4
> >># kernel/kgdb.c 1.3 -> 1.4
> >># arch/ppc/kernel/irq.c 1.36 -> 1.37
> >># include/linux/kgdb.h 1.3 -> 1.4
> >>#
> >># The following is the BitKeeper ChangeSet Log
> >># --------------------------------------------
> >># 04/02/25 trini@xxxxxxxxxxxxxxxxxxx 1.1664
> >># process_breakpoint/schedule_breakpoint.
> >># --------------------------------------------
> >>#
> >>diff -Nru a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c
> >>--- a/arch/i386/kernel/irq.c Wed Feb 25 14:21:32 2004
> >>+++ b/arch/i386/kernel/irq.c Wed Feb 25 14:21:32 2004
> >>@@ -34,6 +34,7 @@
> >> #include <linux/proc_fs.h>
> >> #include <linux/seq_file.h>
> >> #include <linux/kallsyms.h>
> >>+#include <linux/kgdb.h>
> >>
> >> #include <asm/atomic.h>
> >> #include <asm/io.h>
> >>@@ -507,6 +508,8 @@
> >> spin_unlock(&desc->lock);
> >>
> >> irq_exit();
> >>+
> >>+ kgdb_process_breakpoint();
> >>
> >> return 1;
> >> }
> >>diff -Nru a/arch/ppc/kernel/irq.c b/arch/ppc/kernel/irq.c
> >>--- a/arch/ppc/kernel/irq.c Wed Feb 25 14:21:32 2004
> >>+++ b/arch/ppc/kernel/irq.c Wed Feb 25 14:21:32 2004
> >>@@ -46,6 +46,7 @@
> >> #include <linux/random.h>
> >> #include <linux/seq_file.h>
> >> #include <linux/cpumask.h>
> >>+#include <linux/kgdb.h>
> >>
> >> #include <asm/uaccess.h>
> >> #include <asm/bitops.h>
> >>@@ -536,7 +537,9 @@
> >> if (irq != -2 && first)
> >> /* That's not SMP safe ... but who cares ? */
> >> ppc_spurious_interrupts++;
> >>- irq_exit();
> >>+ irq_exit();
> >>+
> >>+ kgdb_process_breakpoint();
> >> }
> >>
> >> unsigned long probe_irq_on (void)
> >>diff -Nru a/arch/x86_64/kernel/irq.c b/arch/x86_64/kernel/irq.c
> >>--- a/arch/x86_64/kernel/irq.c Wed Feb 25 14:21:32 2004
> >>+++ b/arch/x86_64/kernel/irq.c Wed Feb 25 14:21:32 2004
> >>@@ -405,6 +405,8 @@
> >> spin_unlock(&desc->lock);
> >>
> >> irq_exit();
> >>+
> >>+ kgdb_process_breakpoint();
> >> return 1;
> >> }
> >>
> >>diff -Nru a/drivers/net/kgdb_eth.c b/drivers/net/kgdb_eth.c
> >>--- a/drivers/net/kgdb_eth.c Wed Feb 25 14:21:32 2004
> >>+++ b/drivers/net/kgdb_eth.c Wed Feb 25 14:21:32 2004
> >>@@ -60,7 +60,6 @@
> >> static atomic_t in_count;
> >> int kgdboe = 0; /* Default to tty mode */
> >>
> >>-extern void breakpoint(void);
> >> static void rx_hook(struct netpoll *np, int port, char *msg, int len);
> >>
> >> static struct netpoll np = {
> >>@@ -106,14 +105,12 @@
> >>
> >> np->remote_port = port;
> >>
> >>- /* Is this gdb trying to attach? */
> >>- if (!netpoll_trap() && len == 8 && !strncmp(msg, "$Hc-1#09", 8))
> >>- breakpoint();
> >>+ /* Is this gdb trying to attach (!kgdb_connected) or break in
> >>+ * (msg[0] == 3) ? */
> >>+ if (!netpoll_trap() && (!kgdb_connected || msg[0] == 3))
> >>+ kgdb_schedule_breakpoint();
> >>
> >> for (i = 0; i < len; i++) {
> >>- if (msg[i] == 3)
> >>- breakpoint();
> >>-
> >> if (atomic_read(&in_count) >= IN_BUF_SIZE) {
> >> /* buffer overflow, clear it */
> >> in_head = in_tail = 0;
> >>diff -Nru a/drivers/serial/kgdb_8250.c b/drivers/serial/kgdb_8250.c
> >>--- a/drivers/serial/kgdb_8250.c Wed Feb 25 14:21:32 2004
> >>+++ b/drivers/serial/kgdb_8250.c Wed Feb 25 14:21:32 2004
> >>@@ -248,7 +248,7 @@
> >>
> >> /* If we get an interrupt, then KGDB is trying to connect. */
> >> if (!kgdb_connected) {
> >>- breakpoint();
> >>+ kgdb_schedule_breakpoint();
> >> return IRQ_HANDLED;
> >> }
> >>
> >>diff -Nru a/include/linux/kgdb.h b/include/linux/kgdb.h
> >>--- a/include/linux/kgdb.h Wed Feb 25 14:21:32 2004
> >>+++ b/include/linux/kgdb.h Wed Feb 25 14:21:32 2004
> >>@@ -11,8 +11,22 @@
> >> #include <asm/atomic.h>
> >> #include <linux/debugger.h>
> >>
> >>+/*
> >>+ * This file should not include ANY others. This makes it usable
> >>+ * most anywhere without the fear of include order or inclusion.
> >>+ * TODO: Make it so!
> >>+ *
> >>+ * This file may be included all the time. It is only active if
> >>+ * CONFIG_KGDB is defined, otherwise it stubs out all the macros
> >>+ * and entry points.
> >>+ */
> >>+
> >>+#if defined(CONFIG_KGDB) && !defined(__ASSEMBLY__)
> >> /* To enter the debugger explicitly. */
> >>-void breakpoint(void);
> >>+extern void breakpoint(void);
> >>+extern void kgdb_schedule_breakpoint(void);
> >>+extern void kgdb_process_breakpoint(void);
> >>+extern volatile int kgdb_connected;
> >>
> >> #ifndef KGDB_MAX_NO_CPUS
> >> #if CONFIG_NR_CPUS > 8
> >>@@ -112,4 +126,7 @@
> >> char *kgdb_hex2mem(char *buf, char *mem, int count);
> >> int kgdb_get_mem(char *addr, unsigned char *buf, int count);
> >>
> >>+#else
> >>+#define kgdb_process_breakpoint() do {} while(0)
> >>+#endif /* KGDB && !__ASSEMBLY__ */
> >> #endif /* _KGDB_H_ */
> >>diff -Nru a/kernel/kgdb.c b/kernel/kgdb.c
> >>--- a/kernel/kgdb.c Wed Feb 25 14:21:32 2004
> >>+++ b/kernel/kgdb.c Wed Feb 25 14:21:32 2004
> >>@@ -1169,6 +1169,29 @@
> >> printk("Connected.\n");
> >> }
> >>
> >>+/*
> >>+ * Sometimes we need to schedule a breakpoint because we can't break
> >>+ * right where we are.
> >>+ */
> >>+static int kgdb_need_breakpoint[NR_CPUS];
> >>+
> >>+void kgdb_schedule_breakpoint(void)
> >>+{
> >>+ kgdb_need_breakpoint[smp_processor_id()] = 1;
> >>+}
> >>+
> >>+void kgdb_process_breakpoint(void)
> >>+{
> >>+ /*
> >>+ * Handle a breakpoint queued from inside network driver code
> >>+ * to avoid reentrancy issues
> >>+ */
> >>+ if (kgdb_need_breakpoint[smp_processor_id()]) {
> >>+ kgdb_need_breakpoint[smp_processor_id()] = 0;
> >>+ breakpoint();
> >>+ }
> >>+}
> >>+
> >> #ifdef CONFIG_KGDB_CONSOLE
> >> char kgdbconbuf[BUFMAX];
> >
> > -
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