[PATCH v3 6/9] sections: Provide internal __is_kernel() and __is_kernel_text() helper

From: Kefeng Wang
Date: Sun Sep 26 2021 - 03:18:50 EST


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@xxxxxxxxxx>
---
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