[PATCH -tip 4/4] extable: kallsyms: Add in_init_text() and in_core_text() helper

Masami Hiramatsu
2017-08-17T07:18:04Z

Add in_init_text() and in_core_text() helper to check the
address is in between _sinittext and _einittext, and
in between _stext and _etext correspondingly.

This changes extable.c and kallsyms.c to use these helpers
and memory_contains() helper.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
BTW, is_kernel_text() and core_kernel_text() seem different.
is_kernel_text() checks arch dependent area and
in_gate_area_no_mm(), but core_kernel_text() doesn't.
Can we ignore this differences?
---
include/asm-generic/sections.h | 24 ++++++++++++++++++++++++
kernel/extable.c | 18 ++++--------------
kernel/kallsyms.c | 14 +++-----------
3 files changed, 31 insertions(+), 25 deletions(-)

diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index e5da44eddd2f..25ef53fc594c 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -135,4 +135,28 @@ static inline bool init_section_intersects(void *virt, size_t size)
return memory_intersects(__init_begin, __init_end, virt, size);
}

+/**
+ * in_init_text - check if an address is in between _sinittext and _einittext.
+ * @addr: virtual address to be checked
+ *
+ * Returns: true if the address specified by @addr is in between _sinittext
+ * and _einittext, false otherwise.
+ */
+static inline bool in_init_text(unsigned long addr)
+{
+ return memory_contains(_sinittext, _einittext, (void *)addr, 0);
+}
+
+/**
+ * in_core_text - check if an address is in between _stext and _etext.
+ * @addr: virtual address to be checked
+ *
+ * Returns: true if the address specified by @addr is in between _stext
+ * and _etext, false otherwise.
+ */
+static inline bool in_core_text(unsigned long addr)
+{
+ return memory_contains(_stext, _etext, (void *)addr, 0);
+}
+
#endif /* _ASM_GENERIC_SECTIONS_H_ */
diff --git a/kernel/extable.c b/kernel/extable.c
index 38c2412401a1..d8b365c8c916 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -62,22 +62,13 @@ const struct exception_table_entry *search_exception_tables(unsigned long addr)
return e;
}

-static inline int init_kernel_text(unsigned long addr)
-{
- if (addr >= (unsigned long)_sinittext &&
- addr < (unsigned long)_einittext)
- return 1;
- return 0;
-}
-
int notrace core_kernel_text(unsigned long addr)
{
- if (addr >= (unsigned long)_stext &&
- addr < (unsigned long)_etext)
+ if (in_core_text(addr))
return 1;

if (system_state < SYSTEM_RUNNING &&
- init_kernel_text(addr))
+ in_init_text(addr))
return 1;
return 0;
}
@@ -94,8 +85,7 @@ int notrace core_kernel_text(unsigned long addr)
*/
int core_kernel_data(unsigned long addr)
{
- if (addr >= (unsigned long)_sdata &&
- addr < (unsigned long)_edata)
+ if (memory_contains(_sdata, _edata, (void *)addr, 0))
return 1;
return 0;
}
@@ -120,7 +110,7 @@ int __kernel_text_address(unsigned long addr)
* Since we are after the module-symbols check, there's
* no danger of address overlap:
*/
- if (init_kernel_text(addr))
+ if (in_init_text(addr))
return 1;
return 0;
}
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 127e7cfafa55..b1443e845dbd 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -51,17 +51,9 @@ extern const u16 kallsyms_token_index[] __weak;

extern const unsigned long kallsyms_markers[] __weak;

-static inline int is_kernel_inittext(unsigned long addr)
-{
- if (addr >= (unsigned long)_sinittext
- && addr <= (unsigned long)_einittext)
- return 1;
- return 0;
-}
-
static inline int is_kernel_text(unsigned long addr)
{
- if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) ||
+ if (in_core_text(addr) ||
arch_is_kernel_text(addr))
return 1;
return in_gate_area_no_mm(addr);
@@ -79,7 +71,7 @@ static int is_ksym_addr(unsigned long addr)
if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
return is_kernel(addr);

- return is_kernel_text(addr) || is_kernel_inittext(addr);
+ return is_kernel_text(addr) || in_init_text(addr);
}

/*
@@ -272,7 +264,7 @@ static unsigned long get_symbol_pos(unsigned long addr,

/* If we found no next symbol, we use the end of the section. */
if (!symbol_end) {
- if (is_kernel_inittext(addr))
+ if (in_init_text(addr))
symbol_end = (unsigned long)_einittext;
else if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
symbol_end = (unsigned long)_end;