From: Anton Vorontsov <anton.vorontsov@linaro.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Russell King <linux@arm.linux.org.uk>
Cc: "Alan Cox" <alan@linux.intel.com>,
"Jason Wessel" <jason.wessel@windriver.com>,
"Arve Hjønnevåg" <arve@android.com>,
"Colin Cross" <ccross@android.com>,
"Brian Swetland" <swetland@google.com>,
"John Stultz" <john.stultz@linaro.org>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linaro-kernel@lists.linaro.org, patches@linaro.org,
kernel-team@android.com, kgdb-bugreport@lists.sourceforge.net,
linux-serial@vger.kernel.org
Subject: [PATCH 01/11] kernel/debug: Mask KGDB NMI upon entry
Date: Mon, 24 Sep 2012 14:27:50 -0700 [thread overview]
Message-ID: <1348522080-32629-1-git-send-email-anton.vorontsov@linaro.org> (raw)
In-Reply-To: <20120924212648.GA27605@lizard>
The new arch callback should manage NMIs that usually cause KGDB to
enter. That is, not all NMIs should be enabled/disabled, but only
those that issue kgdb_handle_exception().
We must mask it as serial-line interrupt can be used as an NMI, so
if the original KGDB-entry cause was say a breakpoint, then every
input to KDB console will cause KGDB to reenter, which we don't want.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
---
include/linux/kgdb.h | 3 +++
kernel/debug/debug_core.c | 14 +++++++++++---
2 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index c4d2fc1..7800cce 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -240,6 +240,7 @@ extern void kgdb_arch_late(void);
* hardware breakpoints.
* @correct_hw_break: Allow an architecture to specify how to correct the
* hardware debug registers.
+ * @enable_nmi: Manage NMI-triggered entry to KGDB
*/
struct kgdb_arch {
unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE];
@@ -252,6 +253,8 @@ struct kgdb_arch {
void (*disable_hw_break)(struct pt_regs *regs);
void (*remove_all_hw_break)(void);
void (*correct_hw_break)(void);
+
+ void (*enable_nmi)(bool on);
};
/**
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 0557f24..17e073c 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -672,6 +672,10 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
{
struct kgdb_state kgdb_var;
struct kgdb_state *ks = &kgdb_var;
+ int ret = 0;
+
+ if (arch_kgdb_ops.enable_nmi)
+ arch_kgdb_ops.enable_nmi(0);
ks->cpu = raw_smp_processor_id();
ks->ex_vector = evector;
@@ -681,11 +685,15 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
ks->linux_regs = regs;
if (kgdb_reenter_check(ks))
- return 0; /* Ouch, double exception ! */
+ goto out; /* Ouch, double exception ! */
if (kgdb_info[ks->cpu].enter_kgdb != 0)
- return 0;
+ goto out;
- return kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
+ ret = kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
+out:
+ if (arch_kgdb_ops.enable_nmi)
+ arch_kgdb_ops.enable_nmi(1);
+ return ret;
}
int kgdb_nmicallback(int cpu, void *regs)
--
1.7.12
next prev parent reply other threads:[~2012-09-24 21:31 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-24 21:26 [PATCH v9 0/11] KGDB/KDB FIQ (NMI) debugger Anton Vorontsov
2012-09-24 21:27 ` Anton Vorontsov [this message]
2012-09-24 21:27 ` [PATCH 02/11] kdb: Implement disable_nmi command Anton Vorontsov
2012-09-24 21:27 ` [PATCH 03/11] kdb: Turn KGDB_KDB=n stubs into static inlines Anton Vorontsov
2012-09-24 21:27 ` [PATCH 04/11] tty/serial/core: Introduce poll_init callback Anton Vorontsov
2012-09-24 21:27 ` [PATCH 05/11] tty/serial/amba-pl011: Implement " Anton Vorontsov
2012-09-24 21:27 ` [PATCH 06/11] tty/serial/amba-pl011: Quiesce interrupts in poll_get_char Anton Vorontsov
2012-09-24 21:27 ` [PATCH 07/11] tty/serial: Add kgdb_nmi driver Anton Vorontsov
2012-09-24 21:27 ` [PATCH 08/11] ARM: Move some macros from entry-armv to entry-header Anton Vorontsov
2012-09-26 22:05 ` Stephen Boyd
2012-09-26 22:32 ` Anton Vorontsov
2012-09-24 21:27 ` [PATCH 09/11] ARM: Add KGDB/KDB FIQ debugger generic code Anton Vorontsov
2012-09-24 21:27 ` [PATCH 10/11] ARM: VIC: Add a couple of low-level FIQ management helpers Anton Vorontsov
2012-09-24 21:28 ` [PATCH 11/11] ARM: versatile: Make able to use UART ports for KGDB FIQ debugger Anton Vorontsov
2012-09-26 20:54 ` [PATCH v9 0/11] KGDB/KDB FIQ (NMI) debugger Greg Kroah-Hartman
2012-09-26 20:57 ` Anton Vorontsov
-- strict thread matches above, loose matches on Subject: below --
2012-09-19 23:40 [PATCH v8 " Anton Vorontsov
2012-09-19 23:41 ` [PATCH 01/11] kernel/debug: Mask KGDB NMI upon entry Anton Vorontsov
2012-09-13 15:01 [PATCH v7 0/11] KGDB/KDB FIQ (NMI) debugger Anton Vorontsov
2012-09-13 15:03 ` [PATCH 01/11] kernel/debug: Mask KGDB NMI upon entry Anton Vorontsov
2012-09-19 11:52 ` Jason Wessel
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