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From: Will Deacon <will@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: kernel-team@android.com, akpm@linux-foundation.org,
	Will Deacon <will@kernel.org>,
	"K . Prasad" <prasad@linux.vnet.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Frederic Weisbecker <frederic@kernel.org>,
	Christoph Hellwig <hch@lst.de>,
	Quentin Perret <qperret@google.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Masami Hiramatsu <mhiramat@kernel.org>
Subject: [PATCH 1/3] samples/hw_breakpoint: Drop HW_BREAKPOINT_R when reporting writes
Date: Fri, 21 Feb 2020 11:44:02 +0000
Message-ID: <20200221114404.14641-2-will@kernel.org> (raw)
In-Reply-To: <20200221114404.14641-1-will@kernel.org>

Given the name of a kernel symbol, the 'data_breakpoint' test claims to
"report any write operations on the kernel symbol". However, it creates
the breakpoint using both HW_BREAKPOINT_W and HW_BREAKPOINT_R, which
menas it also fires for read access.

Drop HW_BREAKPOINT_R from the breakpoint attributes.

Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
 samples/hw_breakpoint/data_breakpoint.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/samples/hw_breakpoint/data_breakpoint.c b/samples/hw_breakpoint/data_breakpoint.c
index c58504774118..469b36f93696 100644
--- a/samples/hw_breakpoint/data_breakpoint.c
+++ b/samples/hw_breakpoint/data_breakpoint.c
@@ -45,7 +45,7 @@ static int __init hw_break_module_init(void)
 	hw_breakpoint_init(&attr);
 	attr.bp_addr = kallsyms_lookup_name(ksym_name);
 	attr.bp_len = HW_BREAKPOINT_LEN_4;
-	attr.bp_type = HW_BREAKPOINT_W | HW_BREAKPOINT_R;
+	attr.bp_type = HW_BREAKPOINT_W;
 
 	sample_hbp = register_wide_hw_breakpoint(&attr, sample_hbp_handler, NULL);
 	if (IS_ERR((void __force *)sample_hbp)) {
-- 
2.25.0.265.gbab2e86ba0-goog


  reply index

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-21 11:44 [PATCH 0/3] Unexport kallsyms_lookup_name() and kallsyms_on_each_symbol() Will Deacon
2020-02-21 11:44 ` Will Deacon [this message]
2020-02-21 14:12   ` [PATCH 1/3] samples/hw_breakpoint: Drop HW_BREAKPOINT_R when reporting writes Christoph Hellwig
2020-02-21 11:44 ` [PATCH 2/3] samples/hw_breakpoint: Drop use of kallsyms_lookup_name() Will Deacon
2020-02-21 14:13   ` Christoph Hellwig
2020-02-21 14:20     ` Will Deacon
2020-02-21 11:44 ` [PATCH 3/3] kallsyms: Unexport kallsyms_lookup_name() and kallsyms_on_each_symbol() Will Deacon
2020-02-21 11:53   ` Greg Kroah-Hartman
2020-02-21 14:14   ` Christoph Hellwig
2020-02-21 15:11   ` Alexei Starovoitov
2020-02-21 14:27 ` [PATCH 0/3] " Masami Hiramatsu
2020-02-21 14:48   ` Will Deacon
2020-02-21 23:44     ` Masami Hiramatsu
2020-02-21 15:41 ` David Laight
2020-02-21 16:25   ` Quentin Perret
2020-02-25 10:05 ` Miroslav Benes
2020-02-25 12:11   ` Petr Mladek
2020-02-25 15:00     ` Joe Lawrence
2020-02-25 18:01       ` Miroslav Benes
2020-02-26 14:16         ` Joe Lawrence
2020-03-02 19:28 ` Mathieu Desnoyers
2020-03-02 19:36   ` Greg Kroah-Hartman
2020-03-02 19:39     ` Greg Kroah-Hartman
2020-03-02 20:17       ` Mathieu Desnoyers
2020-03-03  6:57         ` Greg Kroah-Hartman
2020-03-03 16:58           ` Mathieu Desnoyers

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