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From: Douglas Anderson <dianders@chromium.org>
To: jason.wessel@windriver.com, daniel.thompson@linaro.org,
	gregkh@linuxfoundation.org
Cc: agross@kernel.org, kgdb-bugreport@lists.sourceforge.net,
	catalin.marinas@arm.com, linux-serial@vger.kernel.org,
	sumit.garg@linaro.org, corbet@lwn.net, mingo@redhat.com,
	will@kernel.org, hpa@zytor.com, tglx@linutronix.de,
	frowand.list@gmail.com, bp@alien8.de, bjorn.andersson@linaro.org,
	jslaby@suse.com, Douglas Anderson <dianders@chromium.org>,
	linux-kernel@vger.kernel.org
Subject: [PATCH v3 06/11] kgdb: Prevent infinite recursive entries to the debugger
Date: Tue, 28 Apr 2020 14:13:46 -0700	[thread overview]
Message-ID: <20200428141218.v3.6.I89de39f68736c9de610e6f241e68d8dbc44bc266@changeid> (raw)
In-Reply-To: <20200428211351.85055-1-dianders@chromium.org>

If we detect that we recursively entered the debugger we should hack
our I/O ops to NULL so that the panic() in the next line won't
actually cause another recursion into the debugger.  The first line of
kgdb_panic() will check this and return.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

Changes in v3:
- ("kgdb: Prevent infinite recursive entries to the debugger") new for v3.

Changes in v2: None

 kernel/debug/debug_core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 503c1630ca76..faf5bd4c34ee 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -532,6 +532,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
 
 	if (exception_level > 1) {
 		dump_stack();
+		kgdb_io_module_registered = false;
 		panic("Recursive entry to debugger");
 	}
 
-- 
2.26.2.303.gf8c07b1a785-goog


  parent reply	other threads:[~2020-04-28 21:15 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-28 21:13 [PATCH v3 00/11] kgdb: Support late serial drivers; enable early debug w/ boot consoles Douglas Anderson
2020-04-28 21:13 ` [PATCH v3 01/11] kgdb: Disable WARN_CONSOLE_UNLOCKED for all kgdb Douglas Anderson
2020-04-28 21:13 ` [PATCH v3 02/11] Revert "kgdboc: disable the console lock when in kgdb" Douglas Anderson
2020-04-28 21:13 ` [PATCH v3 03/11] kgdboc: Use a platform device to handle tty drivers showing up late Douglas Anderson
2020-04-28 21:13 ` [PATCH v3 04/11] kgdb: Delay "kgdbwait" to dbg_late_init() by default Douglas Anderson
2020-04-30 15:49   ` Daniel Thompson
2020-04-30 16:35     ` Doug Anderson
2020-05-04 14:43       ` [Kgdb-bugreport] " Daniel Thompson
2020-04-28 21:13 ` [PATCH v3 05/11] arm64: Add call_break_hook() to early_brk64() for early kgdb Douglas Anderson
2020-05-11 14:59   ` Will Deacon
2020-05-11 22:45     ` Doug Anderson
2020-05-12  7:35       ` Will Deacon
2020-05-12 15:27         ` Doug Anderson
2020-05-13  6:17           ` Will Deacon
2020-05-13 23:08             ` Doug Anderson
2020-04-28 21:13 ` Douglas Anderson [this message]
2020-04-30 16:52   ` [PATCH v3 06/11] kgdb: Prevent infinite recursive entries to the debugger Daniel Thompson
2020-04-28 21:13 ` [PATCH v3 07/11] kgdboc: Add kgdboc_earlycon to support early kgdb using boot consoles Douglas Anderson
2020-05-04 14:13   ` Daniel Thompson
2020-04-28 21:13 ` [PATCH v3 08/11] Documentation: kgdboc: Document new kgdboc_earlycon parameter Douglas Anderson
2020-05-04 14:40   ` Daniel Thompson
2020-04-28 21:13 ` [PATCH v3 09/11] serial: qcom_geni_serial: Support kgdboc_earlycon Douglas Anderson
2020-04-28 21:13 ` [PATCH v3 10/11] serial: 8250_early: " Douglas Anderson
2020-04-28 21:13 ` [PATCH v3 11/11] serial: amba-pl011: " Douglas Anderson

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