vmlinux.lds.h: Provide EMIT_PT_NOTE to indicate export of .notes

In preparation for moving NOTES into RO_DATA, provide a mechanism for architectures that want to emit a PT_NOTE Program Header to do so. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390 Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Will Deacon <will@kernel.org> Cc: x86-ml <x86@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20191029211351.13243-9-keescook@chromium.org
mariux64 · Nov 4, 2019 · 441110a · 441110a
1 parent 7a42d41
commit 441110a
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Showing 7 changed files with 24 additions and 6 deletions.
diff --git a/arch/alpha/kernel/vmlinux.lds.S b/arch/alpha/kernel/vmlinux.lds.S
@@ -1,4 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+
+#define EMITS_PT_NOTE
+
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/thread_info.h>
 #include <asm/cache.h>

diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
@@ -5,6 +5,8 @@
 #include <asm/pgtable.h>
 #include <asm/thread_info.h>
 
+#define EMITS_PT_NOTE
+
 #include <asm-generic/vmlinux.lds.h>
 
 OUTPUT_FORMAT("elf64-ia64-little")

diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
@@ -10,6 +10,11 @@
  */
 #define BSS_FIRST_SECTIONS *(.bss..swapper_pg_dir)
 
+/* Cavium Octeon should not have a separate PT_NOTE Program Header. */
+#ifndef CONFIG_CAVIUM_OCTEON_SOC
+#define EMITS_PT_NOTE
+#endif
+
 #include <asm-generic/vmlinux.lds.h>
 
 #undef mips
@@ -76,12 +81,7 @@ SECTIONS
 		__stop___dbe_table = .;
 	}
 
-#ifdef CONFIG_CAVIUM_OCTEON_SOC
-#define NOTES_HEADER
-#else /* CONFIG_CAVIUM_OCTEON_SOC */
-#define NOTES_HEADER :note
-#endif /* CONFIG_CAVIUM_OCTEON_SOC */
-	NOTES :text NOTES_HEADER
+	NOTES NOTES_HEADERS
 	.dummy : { *(.dummy) } :text
 
 	_sdata = .;			/* Start of data section */

diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
@@ -6,6 +6,7 @@
 #endif
 
 #define BSS_FIRST_SECTIONS *(.bss.prominit)
+#define EMITS_PT_NOTE
 
 #include <asm/page.h>
 #include <asm-generic/vmlinux.lds.h>

diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
@@ -15,6 +15,8 @@
 /* Handle ro_after_init data on our own. */
 #define RO_AFTER_INIT_DATA
 
+#define EMITS_PT_NOTE
+
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/vmlinux.lds.h>
 

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
@@ -21,6 +21,8 @@
 #define LOAD_OFFSET __START_KERNEL_map
 #endif
 
+#define EMITS_PT_NOTE
+
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/asm-offsets.h>
 #include <asm/thread_info.h>

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
@@ -54,6 +54,14 @@
 #define LOAD_OFFSET 0
 #endif
 
+/*
+ * Only some architectures want to have the .notes segment visible in
+ * a separate PT_NOTE ELF Program Header.
+ */
+#ifdef EMITS_PT_NOTE
+#define NOTES_HEADERS		:text :note
+#endif
+
 /* Align . to a 8 byte boundary equals to maximum function alignment. */
 #define ALIGN_FUNCTION()  . = ALIGN(8)