* [PATCH 0/1] PATCH: KGDB/KDB Fix no KDB config problem.
@ 2013-10-03 16:38 Mike Travis
2013-10-03 16:38 ` [PATCH 1/1] " Mike Travis
0 siblings, 1 reply; 8+ messages in thread
From: Mike Travis @ 2013-10-03 16:38 UTC (permalink / raw)
To: Ingo Molnar, Jason Wessel, Peter Zijlstra, Paul Mackerras,
Arnaldo Carvalho de Melo, H. Peter Anvin, Thomas Gleixner,
Andrew Morton
Cc: Dimitri Sivanich, Hedi Berriche, x86, linux-kernel
* Fix build problem when KDB is not defined.
--
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH 1/1] PATCH: KGDB/KDB Fix no KDB config problem.
2013-10-03 16:38 [PATCH 0/1] PATCH: KGDB/KDB Fix no KDB config problem Mike Travis
@ 2013-10-03 16:38 ` Mike Travis
2013-10-03 16:51 ` Ingo Molnar
0 siblings, 1 reply; 8+ messages in thread
From: Mike Travis @ 2013-10-03 16:38 UTC (permalink / raw)
To: Ingo Molnar, Jason Wessel, Peter Zijlstra, Paul Mackerras,
Arnaldo Carvalho de Melo, H. Peter Anvin, Thomas Gleixner,
Andrew Morton
Cc: Dimitri Sivanich, Hedi Berriche, x86, linux-kernel
[-- Attachment #1: fix-non-kdb-config.patch --]
[-- Type: text/plain, Size: 1950 bytes --]
Some code added to the debug_core module had KDB dependencies
that it shouldn't have.
Signed-off-by: Mike Travis <travis@sgi.com>
---
kernel/debug/debug_core.c | 8 ++++----
kernel/debug/debug_core.h | 2 ++
2 files changed, 6 insertions(+), 4 deletions(-)
--- linux.orig/kernel/debug/debug_core.c
+++ linux/kernel/debug/debug_core.c
@@ -575,8 +575,8 @@ return_normal:
raw_spin_lock(&dbg_slave_lock);
#ifdef CONFIG_SMP
- /* If SYSTEM_NMI, slaves are already waiting */
- if (ks->err_code == KDB_REASON_SYSTEM_NMI)
+ /* If send_ready set, slaves are already waiting */
+ if (ks->send_ready)
atomic_set(ks->send_ready, 1);
/* Signal the other CPUs to enter kgdb_wait() */
@@ -682,11 +682,11 @@ kgdb_handle_exception(int evector, int s
if (arch_kgdb_ops.enable_nmi)
arch_kgdb_ops.enable_nmi(0);
+ memset(ks, 0, sizeof(struct kgdb_state));
ks->cpu = raw_smp_processor_id();
ks->ex_vector = evector;
ks->signo = signo;
ks->err_code = ecode;
- ks->kgdb_usethreadid = 0;
ks->linux_regs = regs;
if (kgdb_reenter_check(ks))
@@ -750,7 +750,7 @@ int kgdb_nmicallin(int cpu, int trapnr,
ks->cpu = cpu;
ks->ex_vector = trapnr;
ks->signo = SIGTRAP;
- ks->err_code = KDB_REASON_SYSTEM_NMI;
+ ks->err_code = KGDB_KDB_REASON_SYSTEM_NMI;
ks->linux_regs = regs;
ks->send_ready = send_ready;
kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
--- linux.orig/kernel/debug/debug_core.h
+++ linux/kernel/debug/debug_core.h
@@ -75,11 +75,13 @@ extern int kdb_stub(struct kgdb_state *k
extern int kdb_parse(const char *cmdstr);
extern int kdb_common_init_state(struct kgdb_state *ks);
extern int kdb_common_deinit_state(void);
+#define KGDB_KDB_REASON_SYSTEM_NMI KDB_REASON_SYSTEM_NMI
#else /* ! CONFIG_KGDB_KDB */
static inline int kdb_stub(struct kgdb_state *ks)
{
return DBG_PASS_EVENT;
}
+#define KGDB_KDB_REASON_SYSTEM_NMI 0
#endif /* CONFIG_KGDB_KDB */
#endif /* _DEBUG_CORE_H_ */
--
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] PATCH: KGDB/KDB Fix no KDB config problem.
2013-10-03 16:38 ` [PATCH 1/1] " Mike Travis
@ 2013-10-03 16:51 ` Ingo Molnar
2013-10-03 17:04 ` Mike Travis
0 siblings, 1 reply; 8+ messages in thread
From: Ingo Molnar @ 2013-10-03 16:51 UTC (permalink / raw)
To: Mike Travis
Cc: Ingo Molnar, Jason Wessel, Peter Zijlstra, Paul Mackerras,
Arnaldo Carvalho de Melo, H. Peter Anvin, Thomas Gleixner,
Andrew Morton, Dimitri Sivanich, Hedi Berriche, x86, linux-kernel
* Mike Travis <travis@sgi.com> wrote:
> Some code added to the debug_core module had KDB dependencies
> that it shouldn't have.
>
> Signed-off-by: Mike Travis <travis@sgi.com>
> ---
> kernel/debug/debug_core.c | 8 ++++----
> kernel/debug/debug_core.h | 2 ++
> 2 files changed, 6 insertions(+), 4 deletions(-)
>
> --- linux.orig/kernel/debug/debug_core.c
> +++ linux/kernel/debug/debug_core.c
> @@ -575,8 +575,8 @@ return_normal:
> raw_spin_lock(&dbg_slave_lock);
>
> #ifdef CONFIG_SMP
> - /* If SYSTEM_NMI, slaves are already waiting */
> - if (ks->err_code == KDB_REASON_SYSTEM_NMI)
> + /* If send_ready set, slaves are already waiting */
> + if (ks->send_ready)
> atomic_set(ks->send_ready, 1);
>
> /* Signal the other CPUs to enter kgdb_wait() */
> @@ -682,11 +682,11 @@ kgdb_handle_exception(int evector, int s
> if (arch_kgdb_ops.enable_nmi)
> arch_kgdb_ops.enable_nmi(0);
>
> + memset(ks, 0, sizeof(struct kgdb_state));
> ks->cpu = raw_smp_processor_id();
> ks->ex_vector = evector;
> ks->signo = signo;
> ks->err_code = ecode;
> - ks->kgdb_usethreadid = 0;
> ks->linux_regs = regs;
>
> if (kgdb_reenter_check(ks))
> @@ -750,7 +750,7 @@ int kgdb_nmicallin(int cpu, int trapnr,
> ks->cpu = cpu;
> ks->ex_vector = trapnr;
> ks->signo = SIGTRAP;
> - ks->err_code = KDB_REASON_SYSTEM_NMI;
> + ks->err_code = KGDB_KDB_REASON_SYSTEM_NMI;
> ks->linux_regs = regs;
> ks->send_ready = send_ready;
> kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
> --- linux.orig/kernel/debug/debug_core.h
> +++ linux/kernel/debug/debug_core.h
> @@ -75,11 +75,13 @@ extern int kdb_stub(struct kgdb_state *k
> extern int kdb_parse(const char *cmdstr);
> extern int kdb_common_init_state(struct kgdb_state *ks);
> extern int kdb_common_deinit_state(void);
> +#define KGDB_KDB_REASON_SYSTEM_NMI KDB_REASON_SYSTEM_NMI
> #else /* ! CONFIG_KGDB_KDB */
> static inline int kdb_stub(struct kgdb_state *ks)
> {
> return DBG_PASS_EVENT;
> }
> +#define KGDB_KDB_REASON_SYSTEM_NMI 0
> #endif /* CONFIG_KGDB_KDB */
>
> #endif /* _DEBUG_CORE_H_ */
Hm, the KGDB_KDB_REASON_SYSTEM_NMI definition is a bit ugly. I still think
there are layering violations here and just kludging it around doesn't
solve it - a helper function that keeps kgdb details to the kgdb code
would.
Anyway, if Jason is fine with this solution and upholds his Acked-by then
I'll merge this into the first patch and apply the two patches.
Thanks,
Ingo
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] PATCH: KGDB/KDB Fix no KDB config problem.
2013-10-03 16:51 ` Ingo Molnar
@ 2013-10-03 17:04 ` Mike Travis
2013-10-03 17:15 ` Ingo Molnar
0 siblings, 1 reply; 8+ messages in thread
From: Mike Travis @ 2013-10-03 17:04 UTC (permalink / raw)
To: Ingo Molnar
Cc: Ingo Molnar, Jason Wessel, Peter Zijlstra, Paul Mackerras,
Arnaldo Carvalho de Melo, H. Peter Anvin, Thomas Gleixner,
Andrew Morton, Dimitri Sivanich, Hedi Berriche, x86, linux-kernel
On 10/3/2013 9:51 AM, Ingo Molnar wrote:
>
> * Mike Travis <travis@sgi.com> wrote:
>
>> Some code added to the debug_core module had KDB dependencies
>> that it shouldn't have.
>>
>> Signed-off-by: Mike Travis <travis@sgi.com>
>> ---
>> kernel/debug/debug_core.c | 8 ++++----
>> kernel/debug/debug_core.h | 2 ++
>> 2 files changed, 6 insertions(+), 4 deletions(-)
>>
>> --- linux.orig/kernel/debug/debug_core.c
>> +++ linux/kernel/debug/debug_core.c
>> @@ -575,8 +575,8 @@ return_normal:
>> raw_spin_lock(&dbg_slave_lock);
>>
>> #ifdef CONFIG_SMP
>> - /* If SYSTEM_NMI, slaves are already waiting */
>> - if (ks->err_code == KDB_REASON_SYSTEM_NMI)
>> + /* If send_ready set, slaves are already waiting */
>> + if (ks->send_ready)
>> atomic_set(ks->send_ready, 1);
>>
>> /* Signal the other CPUs to enter kgdb_wait() */
>> @@ -682,11 +682,11 @@ kgdb_handle_exception(int evector, int s
>> if (arch_kgdb_ops.enable_nmi)
>> arch_kgdb_ops.enable_nmi(0);
>>
>> + memset(ks, 0, sizeof(struct kgdb_state));
>> ks->cpu = raw_smp_processor_id();
>> ks->ex_vector = evector;
>> ks->signo = signo;
>> ks->err_code = ecode;
>> - ks->kgdb_usethreadid = 0;
>> ks->linux_regs = regs;
>>
>> if (kgdb_reenter_check(ks))
>> @@ -750,7 +750,7 @@ int kgdb_nmicallin(int cpu, int trapnr,
>> ks->cpu = cpu;
>> ks->ex_vector = trapnr;
>> ks->signo = SIGTRAP;
>> - ks->err_code = KDB_REASON_SYSTEM_NMI;
>> + ks->err_code = KGDB_KDB_REASON_SYSTEM_NMI;
>> ks->linux_regs = regs;
>> ks->send_ready = send_ready;
>> kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
>> --- linux.orig/kernel/debug/debug_core.h
>> +++ linux/kernel/debug/debug_core.h
>> @@ -75,11 +75,13 @@ extern int kdb_stub(struct kgdb_state *k
>> extern int kdb_parse(const char *cmdstr);
>> extern int kdb_common_init_state(struct kgdb_state *ks);
>> extern int kdb_common_deinit_state(void);
>> +#define KGDB_KDB_REASON_SYSTEM_NMI KDB_REASON_SYSTEM_NMI
>> #else /* ! CONFIG_KGDB_KDB */
>> static inline int kdb_stub(struct kgdb_state *ks)
>> {
>> return DBG_PASS_EVENT;
>> }
>> +#define KGDB_KDB_REASON_SYSTEM_NMI 0
>> #endif /* CONFIG_KGDB_KDB */
>>
>> #endif /* _DEBUG_CORE_H_ */
>
> Hm, the KGDB_KDB_REASON_SYSTEM_NMI definition is a bit ugly. I still think
> there are layering violations here and just kludging it around doesn't
> solve it - a helper function that keeps kgdb details to the kgdb code
> would.
>
> Anyway, if Jason is fine with this solution and upholds his Acked-by then
> I'll merge this into the first patch and apply the two patches.
>
> Thanks,
>
> Ingo
>
Would you prefer a simple #ifdef CONFIG_KGDB_KDB around the assignment?
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] PATCH: KGDB/KDB Fix no KDB config problem.
2013-10-03 17:04 ` Mike Travis
@ 2013-10-03 17:15 ` Ingo Molnar
2013-10-03 17:53 ` Mike Travis
0 siblings, 1 reply; 8+ messages in thread
From: Ingo Molnar @ 2013-10-03 17:15 UTC (permalink / raw)
To: Mike Travis
Cc: Ingo Molnar, Jason Wessel, Peter Zijlstra, Paul Mackerras,
Arnaldo Carvalho de Melo, H. Peter Anvin, Thomas Gleixner,
Andrew Morton, Dimitri Sivanich, Hedi Berriche, x86, linux-kernel
* Mike Travis <travis@sgi.com> wrote:
>
>
> On 10/3/2013 9:51 AM, Ingo Molnar wrote:
> >
> > * Mike Travis <travis@sgi.com> wrote:
> >
> >> Some code added to the debug_core module had KDB dependencies
> >> that it shouldn't have.
> >>
> >> Signed-off-by: Mike Travis <travis@sgi.com>
> >> ---
> >> kernel/debug/debug_core.c | 8 ++++----
> >> kernel/debug/debug_core.h | 2 ++
> >> 2 files changed, 6 insertions(+), 4 deletions(-)
> >>
> >> --- linux.orig/kernel/debug/debug_core.c
> >> +++ linux/kernel/debug/debug_core.c
> >> @@ -575,8 +575,8 @@ return_normal:
> >> raw_spin_lock(&dbg_slave_lock);
> >>
> >> #ifdef CONFIG_SMP
> >> - /* If SYSTEM_NMI, slaves are already waiting */
> >> - if (ks->err_code == KDB_REASON_SYSTEM_NMI)
> >> + /* If send_ready set, slaves are already waiting */
> >> + if (ks->send_ready)
> >> atomic_set(ks->send_ready, 1);
> >>
> >> /* Signal the other CPUs to enter kgdb_wait() */
> >> @@ -682,11 +682,11 @@ kgdb_handle_exception(int evector, int s
> >> if (arch_kgdb_ops.enable_nmi)
> >> arch_kgdb_ops.enable_nmi(0);
> >>
> >> + memset(ks, 0, sizeof(struct kgdb_state));
> >> ks->cpu = raw_smp_processor_id();
> >> ks->ex_vector = evector;
> >> ks->signo = signo;
> >> ks->err_code = ecode;
> >> - ks->kgdb_usethreadid = 0;
> >> ks->linux_regs = regs;
> >>
> >> if (kgdb_reenter_check(ks))
> >> @@ -750,7 +750,7 @@ int kgdb_nmicallin(int cpu, int trapnr,
> >> ks->cpu = cpu;
> >> ks->ex_vector = trapnr;
> >> ks->signo = SIGTRAP;
> >> - ks->err_code = KDB_REASON_SYSTEM_NMI;
> >> + ks->err_code = KGDB_KDB_REASON_SYSTEM_NMI;
> >> ks->linux_regs = regs;
> >> ks->send_ready = send_ready;
> >> kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
> >> --- linux.orig/kernel/debug/debug_core.h
> >> +++ linux/kernel/debug/debug_core.h
> >> @@ -75,11 +75,13 @@ extern int kdb_stub(struct kgdb_state *k
> >> extern int kdb_parse(const char *cmdstr);
> >> extern int kdb_common_init_state(struct kgdb_state *ks);
> >> extern int kdb_common_deinit_state(void);
> >> +#define KGDB_KDB_REASON_SYSTEM_NMI KDB_REASON_SYSTEM_NMI
> >> #else /* ! CONFIG_KGDB_KDB */
> >> static inline int kdb_stub(struct kgdb_state *ks)
> >> {
> >> return DBG_PASS_EVENT;
> >> }
> >> +#define KGDB_KDB_REASON_SYSTEM_NMI 0
> >> #endif /* CONFIG_KGDB_KDB */
> >>
> >> #endif /* _DEBUG_CORE_H_ */
> >
> > Hm, the KGDB_KDB_REASON_SYSTEM_NMI definition is a bit ugly. I still think
> > there are layering violations here and just kludging it around doesn't
> > solve it - a helper function that keeps kgdb details to the kgdb code
> > would.
> >
> > Anyway, if Jason is fine with this solution and upholds his Acked-by then
> > I'll merge this into the first patch and apply the two patches.
> >
> > Thanks,
> >
> > Ingo
> >
>
> Would you prefer a simple #ifdef CONFIG_KGDB_KDB around the assignment?
An #ifdef doesn't solve the layering violation!
kernel/debug/debug_core.c didn't have any serious use of #ifdef
CONFIG_KGDB_KDB before (it used it to flavor a few printks) and I'm not
convinced it needs one for this feature either.
So if that whole chunk is kdb dependent, why not shuffle that into a
nicely named function and host it somewhere appropriate in
kernel/debug/kdb/? That function would turn into an empty inline function
in the !CONFIG_KGDB_KDB case.
But ... it's up to Jason really whether he wants to abstract that piece of
code out, I'm just kibitzing here really.
Thanks,
Ingo
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] PATCH: KGDB/KDB Fix no KDB config problem.
2013-10-03 17:15 ` Ingo Molnar
@ 2013-10-03 17:53 ` Mike Travis
2013-10-03 17:58 ` Mike Travis
2013-10-04 6:30 ` Ingo Molnar
0 siblings, 2 replies; 8+ messages in thread
From: Mike Travis @ 2013-10-03 17:53 UTC (permalink / raw)
To: Ingo Molnar
Cc: Ingo Molnar, Jason Wessel, Peter Zijlstra, Paul Mackerras,
Arnaldo Carvalho de Melo, H. Peter Anvin, Thomas Gleixner,
Andrew Morton, Dimitri Sivanich, Hedi Berriche, x86, linux-kernel
On 10/3/2013 10:15 AM, Ingo Molnar wrote:
>
> * Mike Travis <travis@sgi.com> wrote:
>
>>
>>
>> On 10/3/2013 9:51 AM, Ingo Molnar wrote:
>>>
>>> * Mike Travis <travis@sgi.com> wrote:
>>>
>>>> Some code added to the debug_core module had KDB dependencies
>>>> that it shouldn't have.
>>>>
>>>> Signed-off-by: Mike Travis <travis@sgi.com>
>>>> ---
>>>> kernel/debug/debug_core.c | 8 ++++----
>>>> kernel/debug/debug_core.h | 2 ++
>>>> 2 files changed, 6 insertions(+), 4 deletions(-)
>>>>
>>>> --- linux.orig/kernel/debug/debug_core.c
>>>> +++ linux/kernel/debug/debug_core.c
>>>> @@ -575,8 +575,8 @@ return_normal:
>>>> raw_spin_lock(&dbg_slave_lock);
>>>>
>>>> #ifdef CONFIG_SMP
>>>> - /* If SYSTEM_NMI, slaves are already waiting */
>>>> - if (ks->err_code == KDB_REASON_SYSTEM_NMI)
>>>> + /* If send_ready set, slaves are already waiting */
>>>> + if (ks->send_ready)
>>>> atomic_set(ks->send_ready, 1);
>>>>
>>>> /* Signal the other CPUs to enter kgdb_wait() */
>>>> @@ -682,11 +682,11 @@ kgdb_handle_exception(int evector, int s
>>>> if (arch_kgdb_ops.enable_nmi)
>>>> arch_kgdb_ops.enable_nmi(0);
>>>>
>>>> + memset(ks, 0, sizeof(struct kgdb_state));
>>>> ks->cpu = raw_smp_processor_id();
>>>> ks->ex_vector = evector;
>>>> ks->signo = signo;
>>>> ks->err_code = ecode;
>>>> - ks->kgdb_usethreadid = 0;
>>>> ks->linux_regs = regs;
>>>>
>>>> if (kgdb_reenter_check(ks))
>>>> @@ -750,7 +750,7 @@ int kgdb_nmicallin(int cpu, int trapnr,
>>>> ks->cpu = cpu;
>>>> ks->ex_vector = trapnr;
>>>> ks->signo = SIGTRAP;
>>>> - ks->err_code = KDB_REASON_SYSTEM_NMI;
>>>> + ks->err_code = KGDB_KDB_REASON_SYSTEM_NMI;
>>>> ks->linux_regs = regs;
>>>> ks->send_ready = send_ready;
>>>> kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
>>>> --- linux.orig/kernel/debug/debug_core.h
>>>> +++ linux/kernel/debug/debug_core.h
>>>> @@ -75,11 +75,13 @@ extern int kdb_stub(struct kgdb_state *k
>>>> extern int kdb_parse(const char *cmdstr);
>>>> extern int kdb_common_init_state(struct kgdb_state *ks);
>>>> extern int kdb_common_deinit_state(void);
>>>> +#define KGDB_KDB_REASON_SYSTEM_NMI KDB_REASON_SYSTEM_NMI
>>>> #else /* ! CONFIG_KGDB_KDB */
>>>> static inline int kdb_stub(struct kgdb_state *ks)
>>>> {
>>>> return DBG_PASS_EVENT;
>>>> }
>>>> +#define KGDB_KDB_REASON_SYSTEM_NMI 0
>>>> #endif /* CONFIG_KGDB_KDB */
>>>>
>>>> #endif /* _DEBUG_CORE_H_ */
>>>
>>> Hm, the KGDB_KDB_REASON_SYSTEM_NMI definition is a bit ugly. I still think
>>> there are layering violations here and just kludging it around doesn't
>>> solve it - a helper function that keeps kgdb details to the kgdb code
>>> would.
>>>
>>> Anyway, if Jason is fine with this solution and upholds his Acked-by then
>>> I'll merge this into the first patch and apply the two patches.
>>>
>>> Thanks,
>>>
>>> Ingo
>>>
>>
>> Would you prefer a simple #ifdef CONFIG_KGDB_KDB around the assignment?
>
> An #ifdef doesn't solve the layering violation!
>
> kernel/debug/debug_core.c didn't have any serious use of #ifdef
> CONFIG_KGDB_KDB before (it used it to flavor a few printks) and I'm not
> convinced it needs one for this feature either.
>
> So if that whole chunk is kdb dependent, why not shuffle that into a
> nicely named function and host it somewhere appropriate in
> kernel/debug/kdb/? That function would turn into an empty inline function
> in the !CONFIG_KGDB_KDB case.
>
> But ... it's up to Jason really whether he wants to abstract that piece of
> code out, I'm just kibitzing here really.
>
> Thanks,
>
> Ingo
>
If I moved it to KDB then we would lose the capability to enter KGDB
mode and the gdb_stub functionality. The #ifdef could have a comment
to this effect?
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] PATCH: KGDB/KDB Fix no KDB config problem.
2013-10-03 17:53 ` Mike Travis
@ 2013-10-03 17:58 ` Mike Travis
2013-10-04 6:30 ` Ingo Molnar
1 sibling, 0 replies; 8+ messages in thread
From: Mike Travis @ 2013-10-03 17:58 UTC (permalink / raw)
To: Ingo Molnar
Cc: Ingo Molnar, Jason Wessel, Peter Zijlstra, Paul Mackerras,
Arnaldo Carvalho de Melo, H. Peter Anvin, Thomas Gleixner,
Andrew Morton, Dimitri Sivanich, Hedi Berriche, x86, linux-kernel
On 10/3/2013 10:53 AM, Mike Travis wrote:
>
>
> On 10/3/2013 10:15 AM, Ingo Molnar wrote:
>>
>> * Mike Travis <travis@sgi.com> wrote:
>>
>>>
>>>
>>> On 10/3/2013 9:51 AM, Ingo Molnar wrote:
>>>>
>>>> * Mike Travis <travis@sgi.com> wrote:
>>>>
>>>>> Some code added to the debug_core module had KDB dependencies
>>>>> that it shouldn't have.
>>>>>
>>>>> Signed-off-by: Mike Travis <travis@sgi.com>
>>>>> ---
>>>>> kernel/debug/debug_core.c | 8 ++++----
>>>>> kernel/debug/debug_core.h | 2 ++
>>>>> 2 files changed, 6 insertions(+), 4 deletions(-)
>>>>>
>>>>> --- linux.orig/kernel/debug/debug_core.c
>>>>> +++ linux/kernel/debug/debug_core.c
>>>>> @@ -575,8 +575,8 @@ return_normal:
>>>>> raw_spin_lock(&dbg_slave_lock);
>>>>>
>>>>> #ifdef CONFIG_SMP
>>>>> - /* If SYSTEM_NMI, slaves are already waiting */
>>>>> - if (ks->err_code == KDB_REASON_SYSTEM_NMI)
>>>>> + /* If send_ready set, slaves are already waiting */
>>>>> + if (ks->send_ready)
>>>>> atomic_set(ks->send_ready, 1);
>>>>>
>>>>> /* Signal the other CPUs to enter kgdb_wait() */
>>>>> @@ -682,11 +682,11 @@ kgdb_handle_exception(int evector, int s
>>>>> if (arch_kgdb_ops.enable_nmi)
>>>>> arch_kgdb_ops.enable_nmi(0);
>>>>>
>>>>> + memset(ks, 0, sizeof(struct kgdb_state));
>>>>> ks->cpu = raw_smp_processor_id();
>>>>> ks->ex_vector = evector;
>>>>> ks->signo = signo;
>>>>> ks->err_code = ecode;
>>>>> - ks->kgdb_usethreadid = 0;
>>>>> ks->linux_regs = regs;
>>>>>
>>>>> if (kgdb_reenter_check(ks))
>>>>> @@ -750,7 +750,7 @@ int kgdb_nmicallin(int cpu, int trapnr,
>>>>> ks->cpu = cpu;
>>>>> ks->ex_vector = trapnr;
>>>>> ks->signo = SIGTRAP;
>>>>> - ks->err_code = KDB_REASON_SYSTEM_NMI;
>>>>> + ks->err_code = KGDB_KDB_REASON_SYSTEM_NMI;
>>>>> ks->linux_regs = regs;
>>>>> ks->send_ready = send_ready;
>>>>> kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
>>>>> --- linux.orig/kernel/debug/debug_core.h
>>>>> +++ linux/kernel/debug/debug_core.h
>>>>> @@ -75,11 +75,13 @@ extern int kdb_stub(struct kgdb_state *k
>>>>> extern int kdb_parse(const char *cmdstr);
>>>>> extern int kdb_common_init_state(struct kgdb_state *ks);
>>>>> extern int kdb_common_deinit_state(void);
>>>>> +#define KGDB_KDB_REASON_SYSTEM_NMI KDB_REASON_SYSTEM_NMI
>>>>> #else /* ! CONFIG_KGDB_KDB */
>>>>> static inline int kdb_stub(struct kgdb_state *ks)
>>>>> {
>>>>> return DBG_PASS_EVENT;
>>>>> }
>>>>> +#define KGDB_KDB_REASON_SYSTEM_NMI 0
>>>>> #endif /* CONFIG_KGDB_KDB */
>>>>>
>>>>> #endif /* _DEBUG_CORE_H_ */
>>>>
>>>> Hm, the KGDB_KDB_REASON_SYSTEM_NMI definition is a bit ugly. I still think
>>>> there are layering violations here and just kludging it around doesn't
>>>> solve it - a helper function that keeps kgdb details to the kgdb code
>>>> would.
>>>>
>>>> Anyway, if Jason is fine with this solution and upholds his Acked-by then
>>>> I'll merge this into the first patch and apply the two patches.
>>>>
>>>> Thanks,
>>>>
>>>> Ingo
>>>>
>>>
>>> Would you prefer a simple #ifdef CONFIG_KGDB_KDB around the assignment?
>>
>> An #ifdef doesn't solve the layering violation!
>>
>> kernel/debug/debug_core.c didn't have any serious use of #ifdef
>> CONFIG_KGDB_KDB before (it used it to flavor a few printks) and I'm not
>> convinced it needs one for this feature either.
>>
>> So if that whole chunk is kdb dependent, why not shuffle that into a
>> nicely named function and host it somewhere appropriate in
>> kernel/debug/kdb/? That function would turn into an empty inline function
>> in the !CONFIG_KGDB_KDB case.
>>
>> But ... it's up to Jason really whether he wants to abstract that piece of
>> code out, I'm just kibitzing here really.
>>
>> Thanks,
>>
>> Ingo
>>
>
> If I moved it to KDB then we would lose the capability to enter KGDB
> mode and the gdb_stub functionality. The #ifdef could have a comment
> to this effect?
>
Another option would be to pass the code in as the caller knows if KDB
is defined or not?
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] PATCH: KGDB/KDB Fix no KDB config problem.
2013-10-03 17:53 ` Mike Travis
2013-10-03 17:58 ` Mike Travis
@ 2013-10-04 6:30 ` Ingo Molnar
1 sibling, 0 replies; 8+ messages in thread
From: Ingo Molnar @ 2013-10-04 6:30 UTC (permalink / raw)
To: Mike Travis
Cc: Ingo Molnar, Jason Wessel, Peter Zijlstra, Paul Mackerras,
Arnaldo Carvalho de Melo, H. Peter Anvin, Thomas Gleixner,
Andrew Morton, Dimitri Sivanich, Hedi Berriche, x86, linux-kernel
* Mike Travis <travis@sgi.com> wrote:
>
>
> On 10/3/2013 10:15 AM, Ingo Molnar wrote:
> >
> > * Mike Travis <travis@sgi.com> wrote:
> >
> >>
> >>
> >> On 10/3/2013 9:51 AM, Ingo Molnar wrote:
> >>>
> >>> * Mike Travis <travis@sgi.com> wrote:
> >>>
> >>>> Some code added to the debug_core module had KDB dependencies
> >>>> that it shouldn't have.
> >>>>
> >>>> Signed-off-by: Mike Travis <travis@sgi.com>
> >>>> ---
> >>>> kernel/debug/debug_core.c | 8 ++++----
> >>>> kernel/debug/debug_core.h | 2 ++
> >>>> 2 files changed, 6 insertions(+), 4 deletions(-)
> >>>>
> >>>> --- linux.orig/kernel/debug/debug_core.c
> >>>> +++ linux/kernel/debug/debug_core.c
> >>>> @@ -575,8 +575,8 @@ return_normal:
> >>>> raw_spin_lock(&dbg_slave_lock);
> >>>>
> >>>> #ifdef CONFIG_SMP
> >>>> - /* If SYSTEM_NMI, slaves are already waiting */
> >>>> - if (ks->err_code == KDB_REASON_SYSTEM_NMI)
> >>>> + /* If send_ready set, slaves are already waiting */
> >>>> + if (ks->send_ready)
> >>>> atomic_set(ks->send_ready, 1);
> >>>>
> >>>> /* Signal the other CPUs to enter kgdb_wait() */
> >>>> @@ -682,11 +682,11 @@ kgdb_handle_exception(int evector, int s
> >>>> if (arch_kgdb_ops.enable_nmi)
> >>>> arch_kgdb_ops.enable_nmi(0);
> >>>>
> >>>> + memset(ks, 0, sizeof(struct kgdb_state));
> >>>> ks->cpu = raw_smp_processor_id();
> >>>> ks->ex_vector = evector;
> >>>> ks->signo = signo;
> >>>> ks->err_code = ecode;
> >>>> - ks->kgdb_usethreadid = 0;
> >>>> ks->linux_regs = regs;
> >>>>
> >>>> if (kgdb_reenter_check(ks))
> >>>> @@ -750,7 +750,7 @@ int kgdb_nmicallin(int cpu, int trapnr,
> >>>> ks->cpu = cpu;
> >>>> ks->ex_vector = trapnr;
> >>>> ks->signo = SIGTRAP;
> >>>> - ks->err_code = KDB_REASON_SYSTEM_NMI;
> >>>> + ks->err_code = KGDB_KDB_REASON_SYSTEM_NMI;
> >>>> ks->linux_regs = regs;
> >>>> ks->send_ready = send_ready;
> >>>> kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
> >>>> --- linux.orig/kernel/debug/debug_core.h
> >>>> +++ linux/kernel/debug/debug_core.h
> >>>> @@ -75,11 +75,13 @@ extern int kdb_stub(struct kgdb_state *k
> >>>> extern int kdb_parse(const char *cmdstr);
> >>>> extern int kdb_common_init_state(struct kgdb_state *ks);
> >>>> extern int kdb_common_deinit_state(void);
> >>>> +#define KGDB_KDB_REASON_SYSTEM_NMI KDB_REASON_SYSTEM_NMI
> >>>> #else /* ! CONFIG_KGDB_KDB */
> >>>> static inline int kdb_stub(struct kgdb_state *ks)
> >>>> {
> >>>> return DBG_PASS_EVENT;
> >>>> }
> >>>> +#define KGDB_KDB_REASON_SYSTEM_NMI 0
> >>>> #endif /* CONFIG_KGDB_KDB */
> >>>>
> >>>> #endif /* _DEBUG_CORE_H_ */
> >>>
> >>> Hm, the KGDB_KDB_REASON_SYSTEM_NMI definition is a bit ugly. I still think
> >>> there are layering violations here and just kludging it around doesn't
> >>> solve it - a helper function that keeps kgdb details to the kgdb code
> >>> would.
> >>>
> >>> Anyway, if Jason is fine with this solution and upholds his Acked-by then
> >>> I'll merge this into the first patch and apply the two patches.
> >>>
> >>> Thanks,
> >>>
> >>> Ingo
> >>>
> >>
> >> Would you prefer a simple #ifdef CONFIG_KGDB_KDB around the assignment?
> >
> > An #ifdef doesn't solve the layering violation!
> >
> > kernel/debug/debug_core.c didn't have any serious use of #ifdef
> > CONFIG_KGDB_KDB before (it used it to flavor a few printks) and I'm not
> > convinced it needs one for this feature either.
> >
> > So if that whole chunk is kdb dependent, why not shuffle that into a
> > nicely named function and host it somewhere appropriate in
> > kernel/debug/kdb/? That function would turn into an empty inline function
> > in the !CONFIG_KGDB_KDB case.
> >
> > But ... it's up to Jason really whether he wants to abstract that piece of
> > code out, I'm just kibitzing here really.
> >
> > Thanks,
> >
> > Ingo
> >
>
> If I moved it to KDB then we would lose the capability to enter KGDB
> mode and the gdb_stub functionality. The #ifdef could have a comment to
> this effect?
No, this really suggests that there's something else broken around there.
Removing #ifdefs around non-trivial code and architecting it properly
really makes things more reviewable, easier to understand, better
specified and generally less bug prone. So adding an #ifdef around a pair
of printk()s is probably OK - anything that is longer than a line probably
deserves abstracted out.
Thanks,
Ingo
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2013-10-04 6:30 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
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2013-10-03 16:38 [PATCH 0/1] PATCH: KGDB/KDB Fix no KDB config problem Mike Travis
2013-10-03 16:38 ` [PATCH 1/1] " Mike Travis
2013-10-03 16:51 ` Ingo Molnar
2013-10-03 17:04 ` Mike Travis
2013-10-03 17:15 ` Ingo Molnar
2013-10-03 17:53 ` Mike Travis
2013-10-03 17:58 ` Mike Travis
2013-10-04 6:30 ` Ingo Molnar
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