[PATCH 01/15] x86/mm: Rename is_kernel_text to __is_kernel_text

Jiri Olsa
2020-03-12T19:56:28Z

The kbuild test robot reported compile issue on x86 in one of
the following patches that adds <linux/kallsyms.h> include into
<linux/bpf.h>, which is picked up by init_32.c object.

The problem is that <linux/kallsyms.h> defines global function
is_kernel_text which colides with the static function of the
same name defined in init_32.c:

$ make ARCH=i386
...
>> arch/x86/mm/init_32.c:241:19: error: redefinition of 'is_kernel_text'
static inline int is_kernel_text(unsigned long addr)
^~~~~~~~~~~~~~
In file included from include/linux/bpf.h:21:0,
from include/linux/bpf-cgroup.h:5,
from include/linux/cgroup-defs.h:22,
from include/linux/cgroup.h:28,
from include/linux/hugetlb.h:9,
from arch/x86/mm/init_32.c:18:
include/linux/kallsyms.h:31:19: note: previous definition of 'is_kernel_text' was here
static inline int is_kernel_text(unsigned long addr)

Renaming the init_32.c is_kernel_text function to __is_kernel_text.

Acked-by: Song Liu <songliubraving@fb.com>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
arch/x86/mm/init_32.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 23df4885bbed..eb6ede2c3d43 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -238,7 +238,11 @@ page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
}
}

-static inline int is_kernel_text(unsigned long addr)
+/*
+ * The <linux/kallsyms.h> already defines is_kernel_text,
+ * using '__' prefix not to get in conflict.
+ */
+static inline int __is_kernel_text(unsigned long addr)
{
if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end)
return 1;
@@ -328,8 +332,8 @@ kernel_physical_mapping_init(unsigned long start,
addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
PAGE_OFFSET + PAGE_SIZE-1;

- if (is_kernel_text(addr) ||
- is_kernel_text(addr2))
+ if (__is_kernel_text(addr) ||
+ __is_kernel_text(addr2))
prot = PAGE_KERNEL_LARGE_EXEC;

pages_2m++;
@@ -354,7 +358,7 @@ kernel_physical_mapping_init(unsigned long start,
*/
pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);

- if (is_kernel_text(addr))
+ if (__is_kernel_text(addr))
prot = PAGE_KERNEL_EXEC;

pages_4k++;
@@ -881,7 +885,7 @@ static void mark_nxdata_nx(void)
*/
unsigned long start = PFN_ALIGN(_etext);
/*
- * This comes from is_kernel_text upper limit. Also HPAGE where used:
+ * This comes from __is_kernel_text upper limit. Also HPAGE where used:
*/
unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start;

--
2.24.1