[PATCH] debug_core: Add warn message for CONFIG_DEBUG_RODATA enable

[PATCH] debug_core: Add warn message for CONFIG_DEBUG_RODATA enable

[libfetion]

From: Dongdong Deng <libfetion@gmail.com>

The CONFIG_DEBUG_RODATA will limit KGDB/KDB's set breakpoint function,
and CONFIG_DEBUG_RODATA and CONFIG_KGDB could survive together.

Thus most of new user of KGDB/KDB get the set_breakpoint problem
caused by CONFIG_DEBUG_RODATA, and them have to send mail to
kgdb/kdb's mail-list for help.

This patch just adds an extra printk message to warn above case,
in order to provide some useful diagnostics to kgdb/kdb user.

Signed-off-by: Dongdong Deng <libfetion@gmail.com>
---
 kernel/debug/debug_core.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index bad6786..c2d98c1 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -899,6 +899,11 @@ int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops)
 	if (kgdb_break_asap)
 		kgdb_initial_breakpoint();

+#ifdef CONFIG_DEBUG_RODATA
+	printk(KERN_WARNING "kgdb: May need to disable CONFIG_DEBUG_RODATA"
+			" in order to set breakpoints.\n");
+#endif
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(kgdb_register_io_module);
--
1.7.1

Re: [PATCH] debug_core: Add warn message for CONFIG_DEBUG_RODATA enable

[Dongdong Deng]

On Thu, Sep 22, 2011 at 3:50 PM,  <libfetion@gmail.com> wrote:
> From: Dongdong Deng <libfetion@gmail.com>
>
> The CONFIG_DEBUG_RODATA will limit KGDB/KDB's set breakpoint function,
> and CONFIG_DEBUG_RODATA and CONFIG_KGDB could survive together.
>
> Thus most of new user of KGDB/KDB get the set_breakpoint problem
> caused by CONFIG_DEBUG_RODATA, and them have to send mail to
> kgdb/kdb's mail-list for help.
>
> This patch just adds an extra printk message to warn above case,
> in order to provide some useful diagnostics to kgdb/kdb user.
>
> Signed-off-by: Dongdong Deng <libfetion@gmail.com>
> ---
>  kernel/debug/debug_core.c |    5 +++++
>  1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
> index bad6786..c2d98c1 100644
> --- a/kernel/debug/debug_core.c
> +++ b/kernel/debug/debug_core.c
> @@ -899,6 +899,11 @@ int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops)
>        if (kgdb_break_asap)
>                kgdb_initial_breakpoint();
>
> +#ifdef CONFIG_DEBUG_RODATA
> +       printk(KERN_WARNING "kgdb: May need to disable CONFIG_DEBUG_RODATA"
> +                       " in order to set breakpoints.\n");
> +#endif
> +
>        return 0;
>  }
>  EXPORT_SYMBOL_GPL(kgdb_register_io_module);
> --
> 1.7.1
>


Hi Tim,

I am thinking about the case of KGDB, not only the KDB.

How about this patch?  -- add the extra printk message to the debug_core init.

When debug_core init, and  check the CONFIG_DEBUG_RODATA was enabled,
then warn the user that breakpoints will not work...

If it is OK to you,  could you should Signed-off for this patch.  :-)

-Dongdong