[PATCH] x86,kgdb: Always initialize the hw breakpoint attribute

[PATCH] x86,kgdb: Always initialize the hw breakpoint attribute

[Jason Wessel]

It is required to call hw_breakpoint_init() on an attr before using it
in any other calls.  This fixes the problem where kgdb will sometimes
fail to initialize on x86_64.

CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: stable@kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
---
 arch/x86/kernel/kgdb.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index bfba601..d9adcde 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -618,6 +618,7 @@ int kgdb_arch_init(void)
 	 * portion of kgdb because this operation requires mutexs to
 	 * complete.
 	 */
+	hw_breakpoint_init(&attr);
 	attr.bp_addr = (unsigned long)kgdb_arch_init;
 	attr.type = PERF_TYPE_BREAKPOINT;
 	attr.bp_len = HW_BREAKPOINT_LEN_1;
-- 
1.6.3.1.9.g95405b

Re: [PATCH] x86,kgdb: Always initialize the hw breakpoint attribute

[Frederic Weisbecker]

On Tue, Mar 30, 2010 at 01:39:30PM -0500, Jason Wessel wrote:
> It is required to call hw_breakpoint_init() on an attr before using it
> in any other calls.  This fixes the problem where kgdb will sometimes
> fail to initialize on x86_64.
> 
> CC: Frederic Weisbecker <fweisbec@gmail.com>
> CC: Ingo Molnar <mingo@elte.hu>
> CC: stable@kernel.org
> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
> ---
>  arch/x86/kernel/kgdb.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
> index bfba601..d9adcde 100644
> --- a/arch/x86/kernel/kgdb.c
> +++ b/arch/x86/kernel/kgdb.c
> @@ -618,6 +618,7 @@ int kgdb_arch_init(void)
>  	 * portion of kgdb because this operation requires mutexs to
>  	 * complete.
>  	 */
> +	hw_breakpoint_init(&attr);
>  	attr.bp_addr = (unsigned long)kgdb_arch_init;
>  	attr.type = PERF_TYPE_BREAKPOINT;


Minor neat: In this case you don't need to set the type.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>



>  	attr.bp_len = HW_BREAKPOINT_LEN_1;
> -- 
> 1.6.3.1.9.g95405b
>