linux-kernel - [PATCH v3 6/9] sections: Provide internal __is_kernel() and __is_kernel

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Date:   Sun, 26 Sep 2021 15:20:45 +0800
From:   Kefeng Wang <wangkefeng.wang@...wei.com>
To:     <arnd@...db.de>, <linux-arch@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <linuxppc-dev@...ts.ozlabs.org>,
        <rostedt@...dmis.org>, <mingo@...hat.com>, <davem@...emloft.net>,
        <ast@...nel.org>, <ryabinin.a.a@...il.com>,
        <akpm@...ux-foundation.org>
CC:     <mpe@...erman.id.au>, <benh@...nel.crashing.org>,
        <paulus@...ba.org>, <bpf@...r.kernel.org>,
        Kefeng Wang <wangkefeng.wang@...wei.com>
Subject: [PATCH v3 6/9] sections: Provide internal __is_kernel() and __is_kernel_text() helper

An internal __is_kernel() helper which only check the kernel address ranges,
and an internal __is_kernel_text() helper which only check text section ranges.

Signed-off-by: Kefeng Wang <wangkefeng.wang@...wei.com>
---
 include/asm-generic/sections.h | 29 +++++++++++++++++++++++++++++
 include/linux/kallsyms.h       |  4 ++--
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index 811583ca8bd0..a7abeadddc7a 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -186,4 +186,33 @@ static inline bool is_kernel_inittext(unsigned long addr)
 	       addr < (unsigned long)_einittext;
 }
 
+/**
+ * __is_kernel_text - checks if the pointer address is located in the
+ *                    .text section
+ *
+ * @addr: address to check
+ *
+ * Returns: true if the address is located in .text, false otherwise.
+ * Note: an internal helper, only check the range of _stext to _etext.
+ */
+static inline bool __is_kernel_text(unsigned long addr)
+{
+	return addr >= (unsigned long)_stext &&
+	       addr < (unsigned long)_etext;
+}
+
+/**
+ * __is_kernel - checks if the pointer address is located in the kernel range
+ *
+ * @addr: address to check
+ *
+ * Returns: true if the address is located in the kernel range, false otherwise.
+ * Note: an internal helper, only check the range of _stext to _end.
+ */
+static inline bool __is_kernel(unsigned long addr)
+{
+	return addr >= (unsigned long)_stext &&
+	       addr < (unsigned long)_end;
+}
+
 #endif /* _ASM_GENERIC_SECTIONS_H_ */
diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index 8a9d329c927c..5fb17dd4b6fa 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -26,14 +26,14 @@ struct module;
 
 static inline int is_kernel_text(unsigned long addr)
 {
-	if ((addr >= (unsigned long)_stext && addr < (unsigned long)_etext))
+	if (__is_kernel_text(addr))
 		return 1;
 	return in_gate_area_no_mm(addr);
 }
 
 static inline int is_kernel(unsigned long addr)
 {
-	if (addr >= (unsigned long)_stext && addr < (unsigned long)_end)
+	if (__is_kernel(addr))
 		return 1;
 	return in_gate_area_no_mm(addr);
 }
-- 
2.26.2