Thread (54 messages) 54 messages, 8 authors, 2019-11-12
STALE2395d
Revisions (2)
  1. v1 [diff vs current]
  2. v2 current

[PATCH v2 09/29] vmlinux.lds.h: Move Program Header restoration into NOTES macro

From: Kees Cook <hidden>
Date: 2019-10-11 00:06:39
Also in: linux-alpha, linux-arch, linux-arm-kernel, linux-s390, lkml
Subsystem: alpha port, generic include/asm header files, linux for powerpc (32-bit and 64-bit), mips, s390 architecture, the rest, x86 architecture (32-bit and 64-bit) · Maintainers: Richard Henderson, Matt Turner, Magnus Lindholm, Arnd Bergmann, Madhavan Srinivasan, Michael Ellerman, Thomas Bogendoerfer, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen

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

Signed-off-by: Kees Cook <redacted>
---
 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 7cf4958b732d..bfc937ec168c 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 f5dd45ce73f1..97d4299f14dc 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. */
@@ -798,7 +806,8 @@
 		__start_notes = .;					\
 		KEEP(*(.note.*))					\
 		__stop_notes = .;					\
-	}
+	} NOTES_HEADERS							\
+	NOTES_HEADERS_RESTORE
 
 #define INIT_SETUP(initsetup_align)					\
 		. = ALIGN(initsetup_align);				\
-- 
2.17.1
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