[v5 4/6] extable: Add function to search only kernel exception table

From: Santosh Sivaraj <santosh@fossix.org>
To: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	linux-kernel@vger.kernel.org
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
	Mahesh Salgaonkar <mahesh@linux.ibm.com>,
	Reza Arbab <arbab@linux.ibm.com>,
	Balbir Singh <bsingharora@gmail.com>,
	Chandan Rajendra <chandan@linux.vnet.ibm.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Nicholas Piggin <npiggin@gmail.com>,
	christophe leroy <christophe.leroy@c-s.fr>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>
Subject: [v5 4/6] extable: Add function to search only kernel exception table
Date: Tue,  9 Jul 2019 17:45:22 +0530	[thread overview]
Message-ID: <20190709121524.18762-5-santosh@fossix.org> (raw)
In-Reply-To: <20190709121524.18762-1-santosh@fossix.org>

In real mode, the search_exception tables cannot be called because
it also searches the module exception tables if entry is not found
in the kernel exception tables.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
---
 include/linux/extable.h |  2 ++
 kernel/extable.c        | 16 +++++++++++++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/include/linux/extable.h b/include/linux/extable.h
index 41c5b3a25f67..0c2819ba67f0 100644
--- a/include/linux/extable.h
+++ b/include/linux/extable.h
@@ -19,6 +19,8 @@ void trim_init_extable(struct module *m);
 
 /* Given an address, look for it in the exception tables */
 const struct exception_table_entry *search_exception_tables(unsigned long add);
+const struct
+exception_table_entry *search_kernel_exception_table(unsigned long addr);
 
 #ifdef CONFIG_MODULES
 /* For extable.c to search modules' exception tables. */
diff --git a/kernel/extable.c b/kernel/extable.c
index e23cce6e6092..6d544cb79fff 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -40,13 +40,23 @@ void __init sort_main_extable(void)
 	}
 }
 
-/* Given an address, look for it in the exception tables. */
+/* For the given address, look for it in the kernel exception table */
+const
+struct exception_table_entry *search_kernel_exception_table(unsigned long addr)
+{
+	return search_extable(__start___ex_table,
+			      __stop___ex_table - __start___ex_table, addr);
+}
+
+/*
+ * Given an address, look for it in the kernel and the module exception
+ * tables.
+ */
 const struct exception_table_entry *search_exception_tables(unsigned long addr)
 {
 	const struct exception_table_entry *e;
 
-	e = search_extable(__start___ex_table,
-			   __stop___ex_table - __start___ex_table, addr);
+	e = search_kernel_exception_table(addr);
 	if (!e)
 		e = search_module_extables(addr);
 	return e;
-- 
2.20.1

