Re: [PATCH 1/1] PATCH: KGDB/KDB Fix no KDB config problem.

From: Ingo Molnar
Date: Thu Oct 03 2013 - 12:51:30 EST



* Mike Travis <travis@xxxxxxx> wrote:

> Some code added to the debug_core module had KDB dependencies
> that it shouldn't have.
>
> Signed-off-by: Mike Travis <travis@xxxxxxx>
> ---
> 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
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