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

From: Jiri Olsa <jolsa@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>
Cc: "Song Liu" <songliubraving@fb.com>,
	"kbuild test robot" <lkp@intel.com>,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	"Andrii Nakryiko" <andriin@fb.com>, "Yonghong Song" <yhs@fb.com>,
	"Martin KaFai Lau" <kafai@fb.com>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"David Miller" <davem@redhat.com>,
	"Björn Töpel" <bjorn.topel@intel.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"Jesper Dangaard Brouer" <hawk@kernel.org>,
	"Arnaldo Carvalho de Melo" <acme@redhat.com>,
	"Song Liu" <song@kernel.org>
Subject: [PATCH 01/15] x86/mm: Rename is_kernel_text to __is_kernel_text
Date: Thu, 12 Mar 2020 20:55:56 +0100	[thread overview]
Message-ID: <20200312195610.346362-2-jolsa@kernel.org> (raw)
In-Reply-To: <20200312195610.346362-1-jolsa@kernel.org>

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

