[PATCH 09/29] vmlinux.lds.h: Move Program Header restoration into NOTES macro

From: Kees Cook <keescook@chromium.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>,
	Rick Edgecombe <rick.p.edgecombe@intel.com>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org,
	linux-s390@vger.kernel.org, linux-c6x-dev@linux-c6x.org,
	Yoshinori Sato <ysato@users.sourceforge.jp>,
	Michal Simek <monstr@monstr.eu>,
	linux-parisc@vger.kernel.org, linux-xtensa@linux-xtensa.org,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 09/29] vmlinux.lds.h: Move Program Header restoration into NOTES macro
Date: Thu, 26 Sep 2019 10:55:42 -0700	[thread overview]
Message-ID: <20190926175602.33098-10-keescook@chromium.org> (raw)
In-Reply-To: <20190926175602.33098-1-keescook@chromium.org>

In preparation for moving NOTES into RO_DATA, the Program Header
assignment restoration needs to be part of the NOTES macro itself.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/alpha/kernel/vmlinux.lds.S   |  5 +----
 arch/ia64/kernel/vmlinux.lds.S    |  4 +---
 arch/mips/kernel/vmlinux.lds.S    |  3 +--
 arch/powerpc/kernel/vmlinux.lds.S |  4 +---
 arch/s390/kernel/vmlinux.lds.S    |  4 +---
 arch/x86/kernel/vmlinux.lds.S     |  3 +--
 include/asm-generic/vmlinux.lds.h | 13 +++++++++++--
 7 files changed, 17 insertions(+), 19 deletions(-)

diff --git a/arch/alpha/kernel/vmlinux.lds.S b/arch/alpha/kernel/vmlinux.lds.S
index 363a60ba7c31..cdfdc91ce64c 100644
--- a/arch/alpha/kernel/vmlinux.lds.S
+++ b/arch/alpha/kernel/vmlinux.lds.S
@@ -34,10 +34,7 @@ SECTIONS
 	swapper_pg_dir = SWAPPER_PGD;
 	_etext = .;	/* End of text section */
 
-	NOTES :text :note
-	.dummy : {
-		*(.dummy)
-	} :text
+	NOTES
 
 	RODATA
 	EXCEPTION_TABLE(16)
diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index e034a6a4a444..fdcc992ab360 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -70,9 +70,7 @@ SECTIONS {
 	/*
 	 * Read-only data
 	 */
-	NOTES :text :note       /* put .notes in text and mark in PT_NOTE  */
-	code_continues : {
-	} :text                /* switch back to regular program...  */
+	NOTES
 
 	EXCEPTION_TABLE(16)
 
diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
index 1c95612eb800..6a22f531d815 100644
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -81,8 +81,7 @@ SECTIONS
 		__stop___dbe_table = .;
 	}
 
-	NOTES NOTES_HEADERS
-	.dummy : { *(.dummy) } :text
+	NOTES
 
 	_sdata = .;			/* Start of data section */
 	RODATA
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 7e26e20c8324..4f19d814d592 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -164,9 +164,7 @@ SECTIONS
 #endif
 	EXCEPTION_TABLE(0)
 
-	NOTES :text :note
-	/* Restore program header away from PT_NOTE. */
-	.dummy : { *(.dummy) } :text
+	NOTES
 
 /*
  * Init sections discarded at runtime
diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index 646d939346df..f88eedeb915a 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -52,9 +52,7 @@ SECTIONS
 		_etext = .;		/* End of text section */
 	} :text = 0x0700
 
-	NOTES :text :note
-
-	.dummy : { *(.dummy) } :text
+	NOTES
 
 	RO_DATA_SECTION(PAGE_SIZE)
 
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 2e18bf5c1aed..8be25b09c2b7 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -148,8 +148,7 @@ SECTIONS
 		_etext = .;
 	} :text = 0x9090
 
-	NOTES :text :note
-	.dummy : { *(.dummy) } :text
+	NOTES
 
 	EXCEPTION_TABLE(16)
 
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 2cc3ff9ac8c7..6a0a657dfdb4 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -56,10 +56,18 @@
 
 /*
  * Only some architectures want to have the .notes segment visible in
- * a separate PT_NOTE ELF Program Header.
+ * a separate PT_NOTE ELF Program Header. When this happens, it needs
+ * to be visible in both the kernel text's PT_LOAD and the PT_NOTE
+ * Program Headers. In this case, though, the PT_LOAD needs to be made
+ * the default again so that all the following sections don't also end
+ * up in the PT_NOTE Program Header.
  */
 #ifdef EMITS_PT_NOTE
 #define NOTES_HEADERS		:text :note
+#define NOTES_HEADERS_RESTORE	__restore_ph : { *(.__restore_ph) } :text
+#else
+#define NOTES_HEADERS
+#define NOTES_HEADERS_RESTORE
 #endif
 
 /* Align . to a 8 byte boundary equals to maximum function alignment. */
@@ -792,7 +800,8 @@
 		__start_notes = .;					\
 		KEEP(*(.note.*))					\
 		__stop_notes = .;					\
-	}
+	} NOTES_HEADERS							\
+	NOTES_HEADERS_RESTORE
 
 #define INIT_SETUP(initsetup_align)					\
 		. = ALIGN(initsetup_align);				\
-- 
2.17.1

