Re: PPC KGDB changes and some help?

From: Tom Rini
Date: Tue Jan 27 2004 - 13:24:03 EST


On Fri, Jan 23, 2004 at 03:46:05PM -0700, Tom Rini wrote:

> On Thu, Jan 22, 2004 at 11:05:55AM -0700, Tom Rini wrote:
> [snip]
> > First up:
> > We need to call flush_instruction_cache() on a 'c' or 's' command.
> > arch/ppc/kernel/ppc-stub.c | 19 ++++++-------------
> > 1 files changed, 6 insertions(+), 13 deletions(-)
>
> On tpo of this patch, there's the following:
> Put back some code to figure out what signal we're dealing with.

And here's a version that with some help from Daniel always passes the
correct information back to GDB (the original code did not).

arch/ppc/kernel/ppc-stub.c | 63 ++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 60 insertions(+), 3 deletions(-)
--- 1.15/arch/ppc/kernel/ppc-stub.c Thu Jan 22 10:53:06 2004
+++ edited/arch/ppc/kernel/ppc-stub.c Tue Jan 27 11:08:25 2004
@@ -3,6 +3,7 @@
*
* PowerPC-specific bits to work with the common KGDB stub.
*
+ * 1998 (c) Michael AK Tesch (tesch@xxxxxxxxxxx)
* 2003 (c) TimeSys Corporation
* 2004 (c) MontaVista Software, Inc.
* This file is licensed under the terms of the GNU General Public License
@@ -19,13 +20,69 @@
#include <asm/processor.h>
#include <asm/machdep.h>

+/* Convert the hardware trap type code to a unix signal number. */
+/*
+ * This table contains the mapping between PowerPC hardware trap types, and
+ * signals, which are primarily what GDB understands.
+ */
+static struct hard_trap_info
+{
+ unsigned int tt; /* Trap type code for powerpc */
+ unsigned char signo; /* Signal that we map this trap into */
+} hard_trap_info[] = {
+#if defined(CONFIG_40x)
+ { 0x0100, 0x02 /* SIGINT */ }, /* critical input interrupt */
+ { 0x0200, 0x0b /* SIGSEGV */ }, /* machine check */
+ { 0x0300, 0x0b /* SIGSEGV */ }, /* data storage */
+ { 0x0400, 0x0a /* SIGBUS */ }, /* instruction storage */
+ { 0x0500, 0x02 /* SIGINT */ }, /* interrupt */
+ { 0x0600, 0x0a /* SIGBUS */ }, /* alignment */
+ { 0x0700, 0x04 /* SIGILL */ }, /* program */
+ { 0x0800, 0x04 /* SIGILL */ }, /* reserved */
+ { 0x0900, 0x04 /* SIGILL */ }, /* reserved */
+ { 0x0a00, 0x04 /* SIGILL */ }, /* reserved */
+ { 0x0b00, 0x04 /* SIGILL */ }, /* reserved */
+ { 0x0c00, 0x14 /* SIGCHLD */ }, /* syscall */
+ { 0x0d00, 0x04 /* SIGILL */ }, /* reserved */
+ { 0x0e00, 0x04 /* SIGILL */ }, /* reserved */
+ { 0x0f00, 0x04 /* SIGILL */ }, /* reserved */
+ { 0x2000, 0x05 /* SIGTRAP */}, /* debug */
+#else
+ { 0x0200, 0x0b /* SIGSEGV */ }, /* machine check */
+ { 0x0300, 0x0b /* SIGSEGV */ }, /* address error (store) */
+ { 0x0400, 0x0a /* SIGBUS */ }, /* instruction bus error */
+ { 0x0500, 0x02 /* SIGINT */ }, /* interrupt */
+ { 0x0600, 0x0a /* SIGBUS */ }, /* alingment */
+ { 0x0700, 0x05 /* SIGTRAP */ }, /* breakpoint trap */
+ { 0x0800, 0x08 /* SIGFPE */}, /* fpu unavail */
+ { 0x0900, 0x0e /* SIGALRM */ }, /* decrementer */
+ { 0x0a00, 0x04 /* SIGILL */ }, /* reserved */
+ { 0x0b00, 0x04 /* SIGILL */ }, /* reserved */
+ { 0x0c00, 0x14 /* SIGCHLD */ }, /* syscall */
+ { 0x0d00, 0x05 /* SIGTRAP */ }, /* single-step/watch */
+ { 0x0e00, 0x08 /* SIGFPE */ }, /* fp assist */
+#endif
+ { 0x0000, 0x000 } /* Must be last */
+};
+
+static int computeSignal(unsigned int tt)
+{
+ struct hard_trap_info *ht;
+
+ for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
+ if (ht->tt == tt)
+ return ht->signo;
+
+ return SIGHUP; /* default for things we don't know about */
+}
+
/*
* Routines
*/
static void
kgdb_debugger(struct pt_regs *regs)
{
- (*linux_debug_hook) (0, 0, 0, regs);
+ (*linux_debug_hook) (0, computeSignal(regs->trap), 0, regs);
return;
}

@@ -52,14 +109,14 @@
int
kgdb_iabr_match(struct pt_regs *regs)
{
- (*linux_debug_hook) (0, 0, 0, regs);
+ (*linux_debug_hook) (0, computeSignal(regs->trap), 0, regs);
return 1;
}

int
kgdb_dabr_match(struct pt_regs *regs)
{
- (*linux_debug_hook) (0, 0, 0, regs);
+ (*linux_debug_hook) (0, computeSignal(regs->trap), 0, regs);
return 1;
}


--
Tom Rini
http://gate.crashing.org/~trini/
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