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* [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES
@ 2019-09-26 17:55 Kees Cook
  2019-09-26 17:55 ` [PATCH 01/29] powerpc: Rename "notes" PT_NOTE to "note" Kees Cook
                   ` (29 more replies)
  0 siblings, 30 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

This series works to move the linker sections for NOTES and
EXCEPTION_TABLE into the RO_DATA area, where they belong on most
(all?) architectures. The problem being addressed was the discovery
by Rick Edgecombe that the exception table was accidentally marked
executable while he was developing his execute-only-memory series. When
permissions were flipped from readable-and-executable to only-executable,
the exception table became unreadable, causing things to explode rather
badly. :)

Roughly speaking, the steps are:

- regularize the linker names for PT_NOTE and PT_LOAD program headers
  (to "note" and "text" respectively)
- regularize restoration of linker section to program header assignment
  (when PT_NOTE exists)
- move NOTES into RO_DATA
- finish macro naming conversions for RO_DATA and RW_DATA
- move EXCEPTION_TABLE into RO_DATA on architectures where this is clear
- clean up some x86-specific reporting of kernel memory resources
- switch x86 linker fill byte from x90 (NOP) to 0xcc (INT3), just because
  I finally realized what that trailing ": 0x9090" meant -- and we should
  trap, not slide, if execution lands in section padding

Since these changes are treewide, I'd love to get architecture-maintainer
Acks and either have this live in x86 -tip or in my own tree, however
people think it should go.

Thanks!

-Kees

Kees Cook (29):
  powerpc: Rename "notes" PT_NOTE to "note"
  powerpc: Remove PT_NOTE workaround
  powerpc: Rename PT_LOAD identifier "kernel" to "text"
  alpha: Rename PT_LOAD identifier "kernel" to "text"
  ia64: Rename PT_LOAD identifier "code" to "text"
  s390: Move RO_DATA into "text" PT_LOAD Program Header
  x86: Restore "text" Program Header with dummy section
  vmlinux.lds.h: Provide EMIT_PT_NOTE to indicate export of .notes
  vmlinux.lds.h: Move Program Header restoration into NOTES macro
  vmlinux.lds.h: Move NOTES into RO_DATA
  vmlinux.lds.h: Replace RODATA with RO_DATA
  vmlinux.lds.h: Replace RO_DATA_SECTION with RO_DATA
  vmlinux.lds.h: Replace RW_DATA_SECTION with RW_DATA
  vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA
  x86: Actually use _etext for end of text segment
  x86: Move EXCEPTION_TABLE to RO_DATA segment
  alpha: Move EXCEPTION_TABLE to RO_DATA segment
  arm64: Move EXCEPTION_TABLE to RO_DATA segment
  c6x: Move EXCEPTION_TABLE to RO_DATA segment
  h8300: Move EXCEPTION_TABLE to RO_DATA segment
  ia64: Move EXCEPTION_TABLE to RO_DATA segment
  microblaze: Move EXCEPTION_TABLE to RO_DATA segment
  parisc: Move EXCEPTION_TABLE to RO_DATA segment
  powerpc: Move EXCEPTION_TABLE to RO_DATA segment
  xtensa: Move EXCEPTION_TABLE to RO_DATA segment
  x86/mm: Remove redundant &s on addresses
  x86/mm: Report which part of kernel image is freed
  x86/mm: Report actual image regions in /proc/iomem
  x86: Use INT3 instead of NOP for linker fill bytes

 arch/alpha/kernel/vmlinux.lds.S      | 18 +++++-----
 arch/arc/kernel/vmlinux.lds.S        |  6 ++--
 arch/arm/kernel/vmlinux-xip.lds.S    |  4 +--
 arch/arm/kernel/vmlinux.lds.S        |  4 +--
 arch/arm64/kernel/vmlinux.lds.S      |  9 ++---
 arch/c6x/kernel/vmlinux.lds.S        |  8 ++---
 arch/csky/kernel/vmlinux.lds.S       |  5 ++-
 arch/h8300/kernel/vmlinux.lds.S      |  9 ++---
 arch/hexagon/kernel/vmlinux.lds.S    |  5 ++-
 arch/ia64/kernel/vmlinux.lds.S       | 20 +++++------
 arch/m68k/kernel/vmlinux-nommu.lds   |  4 +--
 arch/m68k/kernel/vmlinux-std.lds     |  2 +-
 arch/m68k/kernel/vmlinux-sun3.lds    |  2 +-
 arch/microblaze/kernel/vmlinux.lds.S |  8 ++---
 arch/mips/kernel/vmlinux.lds.S       | 15 ++++----
 arch/nds32/kernel/vmlinux.lds.S      |  5 ++-
 arch/nios2/kernel/vmlinux.lds.S      |  5 ++-
 arch/openrisc/kernel/vmlinux.lds.S   |  7 ++--
 arch/parisc/kernel/vmlinux.lds.S     | 11 +++---
 arch/powerpc/kernel/vmlinux.lds.S    | 37 ++++---------------
 arch/riscv/kernel/vmlinux.lds.S      |  5 ++-
 arch/s390/kernel/vmlinux.lds.S       | 12 +++----
 arch/sh/kernel/vmlinux.lds.S         |  3 +-
 arch/sparc/kernel/vmlinux.lds.S      |  3 +-
 arch/um/include/asm/common.lds.S     |  3 +-
 arch/unicore32/kernel/vmlinux.lds.S  |  5 ++-
 arch/x86/include/asm/processor.h     |  2 +-
 arch/x86/include/asm/sections.h      |  1 -
 arch/x86/kernel/setup.c              | 12 ++++++-
 arch/x86/kernel/vmlinux.lds.S        | 16 ++++-----
 arch/x86/mm/init.c                   |  8 ++---
 arch/x86/mm/init_64.c                | 16 +++++----
 arch/x86/mm/pti.c                    |  2 +-
 arch/xtensa/kernel/vmlinux.lds.S     |  8 ++---
 include/asm-generic/vmlinux.lds.h    | 53 ++++++++++++++++++++--------
 35 files changed, 159 insertions(+), 174 deletions(-)

-- 
2.17.1


^ permalink raw reply	[flat|nested] 42+ messages in thread

* [PATCH 01/29] powerpc: Rename "notes" PT_NOTE to "note"
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 02/29] powerpc: Remove PT_NOTE workaround Kees Cook
                   ` (28 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The Program Header identifiers are internal to the linker scripts. In
preparation for moving the NOTES segment declaration into RO_DATA,
standardize the identifier for the PT_NOTE entry to "note" as used by
all other architectures that emit PT_NOTE.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/powerpc/kernel/vmlinux.lds.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 060a1acd7c6d..81e672654789 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -19,7 +19,7 @@ ENTRY(_stext)
 
 PHDRS {
 	kernel PT_LOAD FLAGS(7); /* RWX */
-	notes PT_NOTE FLAGS(0);
+	note PT_NOTE FLAGS(0);
 	dummy PT_NOTE FLAGS(0);
 
 	/* binutils < 2.18 has a bug that makes it misbehave when taking an
@@ -177,7 +177,7 @@ SECTIONS
 #endif
 	EXCEPTION_TABLE(0)
 
-	NOTES :kernel :notes
+	NOTES :kernel :note
 
 	/* The dummy segment contents for the bug workaround mentioned above
 	   near PHDRS.  */
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 02/29] powerpc: Remove PT_NOTE workaround
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
  2019-09-26 17:55 ` [PATCH 01/29] powerpc: Rename "notes" PT_NOTE to "note" Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 03/29] powerpc: Rename PT_LOAD identifier "kernel" to "text" Kees Cook
                   ` (27 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The kernel requires gcc 4.6 now, so this PT_NOTE workaround can be
removed in preparation for moving NOTES into RO_DATA.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/powerpc/kernel/vmlinux.lds.S | 24 ++----------------------
 1 file changed, 2 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 81e672654789..a3c8492b2b19 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -20,20 +20,6 @@ ENTRY(_stext)
 PHDRS {
 	kernel PT_LOAD FLAGS(7); /* RWX */
 	note PT_NOTE FLAGS(0);
-	dummy PT_NOTE FLAGS(0);
-
-	/* binutils < 2.18 has a bug that makes it misbehave when taking an
-	   ELF file with all segments at load address 0 as input.  This
-	   happens when running "strip" on vmlinux, because of the AT() magic
-	   in this linker script.  People using GCC >= 4.2 won't run into
-	   this problem, because the "build-id" support will put some data
-	   into the "notes" segment (at a non-zero load address).
-
-	   To work around this, we force some data into both the "dummy"
-	   segment and the kernel segment, so the dummy segment will get a
-	   non-zero load address.  It's not enough to always create the
-	   "notes" segment, since if nothing gets assigned to it, its load
-	   address will be zero.  */
 }
 
 #ifdef CONFIG_PPC64
@@ -178,14 +164,8 @@ SECTIONS
 	EXCEPTION_TABLE(0)
 
 	NOTES :kernel :note
-
-	/* The dummy segment contents for the bug workaround mentioned above
-	   near PHDRS.  */
-	.dummy : AT(ADDR(.dummy) - LOAD_OFFSET) {
-		LONG(0)
-		LONG(0)
-		LONG(0)
-	} :kernel :dummy
+	/* Restore program header away from PT_NOTE. */
+	.dummy : { *(.dummy) } :kernel
 
 /*
  * Init sections discarded at runtime
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 03/29] powerpc: Rename PT_LOAD identifier "kernel" to "text"
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
  2019-09-26 17:55 ` [PATCH 01/29] powerpc: Rename "notes" PT_NOTE to "note" Kees Cook
  2019-09-26 17:55 ` [PATCH 02/29] powerpc: Remove PT_NOTE workaround Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 04/29] alpha: " Kees Cook
                   ` (26 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

In preparation for moving NOTES into RO_DATA, this renames the linker
script internal identifier for the PT_LOAD Program Header from "kernel"
to "text" to match other architectures.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/powerpc/kernel/vmlinux.lds.S | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index a3c8492b2b19..e184a63aa5b0 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -18,7 +18,7 @@
 ENTRY(_stext)
 
 PHDRS {
-	kernel PT_LOAD FLAGS(7); /* RWX */
+	text PT_LOAD FLAGS(7); /* RWX */
 	note PT_NOTE FLAGS(0);
 }
 
@@ -63,7 +63,7 @@ SECTIONS
 #else /* !CONFIG_PPC64 */
 		HEAD_TEXT
 #endif
-	} :kernel
+	} :text
 
 	__head_end = .;
 
@@ -112,7 +112,7 @@ SECTIONS
 		__got2_end = .;
 #endif /* CONFIG_PPC32 */
 
-	} :kernel
+	} :text
 
 	. = ALIGN(ETEXT_ALIGN_SIZE);
 	_etext = .;
@@ -163,9 +163,9 @@ SECTIONS
 #endif
 	EXCEPTION_TABLE(0)
 
-	NOTES :kernel :note
+	NOTES :text :note
 	/* Restore program header away from PT_NOTE. */
-	.dummy : { *(.dummy) } :kernel
+	.dummy : { *(.dummy) } :text
 
 /*
  * Init sections discarded at runtime
@@ -180,7 +180,7 @@ SECTIONS
 #ifdef CONFIG_PPC64
 		*(.tramp.ftrace.init);
 #endif
-	} :kernel
+	} :text
 
 	/* .exit.text is discarded at runtime, not link time,
 	 * to deal with references from __bug_table
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 04/29] alpha: Rename PT_LOAD identifier "kernel" to "text"
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (2 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 03/29] powerpc: Rename PT_LOAD identifier "kernel" to "text" Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 05/29] ia64: Rename PT_LOAD identifier "code" " Kees Cook
                   ` (25 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

In preparation for moving NOTES into RO_DATA, this renames the linker
script internal identifier for the PT_LOAD Program Header from "kernel"
to "text" to match other architectures.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/alpha/kernel/vmlinux.lds.S | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/alpha/kernel/vmlinux.lds.S b/arch/alpha/kernel/vmlinux.lds.S
index c4b5ceceab52..781090cacc96 100644
--- a/arch/alpha/kernel/vmlinux.lds.S
+++ b/arch/alpha/kernel/vmlinux.lds.S
@@ -8,7 +8,7 @@
 OUTPUT_FORMAT("elf64-alpha")
 OUTPUT_ARCH(alpha)
 ENTRY(__start)
-PHDRS { kernel PT_LOAD; note PT_NOTE; }
+PHDRS { text PT_LOAD; note PT_NOTE; }
 jiffies = jiffies_64;
 SECTIONS
 {
@@ -27,14 +27,14 @@ SECTIONS
 		LOCK_TEXT
 		*(.fixup)
 		*(.gnu.warning)
-	} :kernel
+	} :text
 	swapper_pg_dir = SWAPPER_PGD;
 	_etext = .;	/* End of text section */
 
-	NOTES :kernel :note
+	NOTES :text :note
 	.dummy : {
 		*(.dummy)
-	} :kernel
+	} :text
 
 	RODATA
 	EXCEPTION_TABLE(16)
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 05/29] ia64: Rename PT_LOAD identifier "code" to "text"
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (3 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 04/29] alpha: " Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 06/29] s390: Move RO_DATA into "text" PT_LOAD Program Header Kees Cook
                   ` (24 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

In preparation for moving NOTES into RO_DATA, this renames the linker
script internal identifier for the PT_LOAD Program Header from "code"
to "text" to match other architectures.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/ia64/kernel/vmlinux.lds.S | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index 0da58cf8e213..c1067992fcd1 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -13,7 +13,7 @@ ENTRY(phys_start)
 jiffies = jiffies_64;
 
 PHDRS {
-	code   PT_LOAD;
+	text   PT_LOAD;
 	percpu PT_LOAD;
 	data   PT_LOAD;
 	note   PT_NOTE;
@@ -36,7 +36,7 @@ SECTIONS {
 	phys_start = _start - LOAD_OFFSET;
 
 	code : {
-	} :code
+	} :text
 	. = KERNEL_START;
 
 	_text = .;
@@ -68,9 +68,9 @@ SECTIONS {
 	/*
 	 * Read-only data
 	 */
-	NOTES :code :note       /* put .notes in text and mark in PT_NOTE  */
+	NOTES :text :note       /* put .notes in text and mark in PT_NOTE  */
 	code_continues : {
-	} : code               /* switch back to regular program...  */
+	} :text                /* switch back to regular program...  */
 
 	EXCEPTION_TABLE(16)
 
@@ -102,9 +102,9 @@ SECTIONS {
 		__start_unwind = .;
 		*(.IA_64.unwind*)
 		__end_unwind = .;
-	} :code :unwind
+	} :text :unwind
 	code_continues2 : {
-	} : code
+	} :text
 
 	RODATA
 
@@ -224,7 +224,7 @@ SECTIONS {
 	_end = .;
 
 	code : {
-	} :code
+	} :text
 
 	STABS_DEBUG
 	DWARF_DEBUG
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 06/29] s390: Move RO_DATA into "text" PT_LOAD Program Header
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (4 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 05/29] ia64: Rename PT_LOAD identifier "code" " Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 07/29] x86: Restore "text" Program Header with dummy section Kees Cook
                   ` (23 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

In preparation for moving NOTES into RO_DATA, this moves RO_DATA back
into the "text" PT_LOAD Program Header, as done with other
architectures. The "data" PT_LOAD now starts with the writable data
section.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/s390/kernel/vmlinux.lds.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index 7e0eb4020917..13294fef473e 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -52,7 +52,7 @@ SECTIONS
 
 	NOTES :text :note
 
-	.dummy : { *(.dummy) } :data
+	.dummy : { *(.dummy) } :text
 
 	RO_DATA_SECTION(PAGE_SIZE)
 
@@ -64,7 +64,7 @@ SECTIONS
 	.data..ro_after_init : {
 		 *(.data..ro_after_init)
 		JUMP_TABLE_DATA
-	}
+	} :data
 	EXCEPTION_TABLE(16)
 	. = ALIGN(PAGE_SIZE);
 	__end_ro_after_init = .;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 07/29] x86: Restore "text" Program Header with dummy section
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (5 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 06/29] s390: Move RO_DATA into "text" PT_LOAD Program Header Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-10-10 10:33   ` Borislav Petkov
  2019-09-26 17:55 ` [PATCH 08/29] vmlinux.lds.h: Provide EMIT_PT_NOTE to indicate export of .notes Kees Cook
                   ` (22 subsequent siblings)
  29 siblings, 1 reply; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

Instead of depending on markings in the section following NOTES to
restore the associated Program Header, use a dummy section, as done
in other architectures. This is preparation for moving NOTES into the
RO_DATA macro.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/kernel/vmlinux.lds.S | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index e2feacf921a0..788e78978030 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -147,8 +147,9 @@ SECTIONS
 	} :text = 0x9090
 
 	NOTES :text :note
+	.dummy : { *(.dummy) } :text
 
-	EXCEPTION_TABLE(16) :text = 0x9090
+	EXCEPTION_TABLE(16)
 
 	/* .text should occupy whole number of pages */
 	. = ALIGN(PAGE_SIZE);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 08/29] vmlinux.lds.h: Provide EMIT_PT_NOTE to indicate export of .notes
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (6 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 07/29] x86: Restore "text" Program Header with dummy section Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-10-10 10:40   ` Borislav Petkov
  2019-09-26 17:55 ` [PATCH 09/29] vmlinux.lds.h: Move Program Header restoration into NOTES macro Kees Cook
                   ` (21 subsequent siblings)
  29 siblings, 1 reply; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

In preparation for moving NOTES into RO_DATA, this provides a mechanism
for architectures that want to emit a PT_NOTE Program Header to do so.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/alpha/kernel/vmlinux.lds.S   |  3 +++
 arch/ia64/kernel/vmlinux.lds.S    |  2 ++
 arch/mips/kernel/vmlinux.lds.S    | 12 ++++++------
 arch/powerpc/kernel/vmlinux.lds.S |  1 +
 arch/s390/kernel/vmlinux.lds.S    |  2 ++
 arch/x86/kernel/vmlinux.lds.S     |  2 ++
 include/asm-generic/vmlinux.lds.h |  8 ++++++++
 7 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/arch/alpha/kernel/vmlinux.lds.S b/arch/alpha/kernel/vmlinux.lds.S
index 781090cacc96..363a60ba7c31 100644
--- 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
index c1067992fcd1..e034a6a4a444 100644
--- 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
index 33ee0d18fb0a..1c95612eb800 100644
--- 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
index e184a63aa5b0..7e26e20c8324 100644
--- 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
index 13294fef473e..646d939346df 100644
--- 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
index 788e78978030..2e18bf5c1aed 100644
--- 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
index cd28f63bfbc7..2cc3ff9ac8c7 100644
--- 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)
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 09/29] vmlinux.lds.h: Move Program Header restoration into NOTES macro
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (7 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 08/29] vmlinux.lds.h: Provide EMIT_PT_NOTE to indicate export of .notes Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 10/29] vmlinux.lds.h: Move NOTES into RO_DATA Kees Cook
                   ` (20 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

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


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 10/29] vmlinux.lds.h: Move NOTES into RO_DATA
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (8 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 09/29] vmlinux.lds.h: Move Program Header restoration into NOTES macro Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 11/29] vmlinux.lds.h: Replace RODATA with RO_DATA Kees Cook
                   ` (19 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The .notes section should be non-executable read-only data. As such, it
can live in the RO_DATA macro instead of being per-architecture defined.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/alpha/kernel/vmlinux.lds.S      | 2 --
 arch/arc/kernel/vmlinux.lds.S        | 2 --
 arch/arm/kernel/vmlinux-xip.lds.S    | 2 --
 arch/arm/kernel/vmlinux.lds.S        | 2 --
 arch/arm64/kernel/vmlinux.lds.S      | 1 -
 arch/c6x/kernel/vmlinux.lds.S        | 1 -
 arch/csky/kernel/vmlinux.lds.S       | 1 -
 arch/h8300/kernel/vmlinux.lds.S      | 1 -
 arch/hexagon/kernel/vmlinux.lds.S    | 1 -
 arch/ia64/kernel/vmlinux.lds.S       | 2 --
 arch/microblaze/kernel/vmlinux.lds.S | 1 -
 arch/mips/kernel/vmlinux.lds.S       | 2 --
 arch/nds32/kernel/vmlinux.lds.S      | 1 -
 arch/nios2/kernel/vmlinux.lds.S      | 1 -
 arch/openrisc/kernel/vmlinux.lds.S   | 1 -
 arch/parisc/kernel/vmlinux.lds.S     | 1 -
 arch/powerpc/kernel/vmlinux.lds.S    | 2 --
 arch/riscv/kernel/vmlinux.lds.S      | 1 -
 arch/s390/kernel/vmlinux.lds.S       | 2 --
 arch/sh/kernel/vmlinux.lds.S         | 1 -
 arch/sparc/kernel/vmlinux.lds.S      | 1 -
 arch/um/include/asm/common.lds.S     | 1 -
 arch/unicore32/kernel/vmlinux.lds.S  | 1 -
 arch/x86/kernel/vmlinux.lds.S        | 2 --
 arch/xtensa/kernel/vmlinux.lds.S     | 1 -
 include/asm-generic/vmlinux.lds.h    | 9 +++++----
 26 files changed, 5 insertions(+), 38 deletions(-)

diff --git a/arch/alpha/kernel/vmlinux.lds.S b/arch/alpha/kernel/vmlinux.lds.S
index cdfdc91ce64c..bf28043485f6 100644
--- a/arch/alpha/kernel/vmlinux.lds.S
+++ b/arch/alpha/kernel/vmlinux.lds.S
@@ -34,8 +34,6 @@ SECTIONS
 	swapper_pg_dir = SWAPPER_PGD;
 	_etext = .;	/* End of text section */
 
-	NOTES
-
 	RODATA
 	EXCEPTION_TABLE(16)
 
diff --git a/arch/arc/kernel/vmlinux.lds.S b/arch/arc/kernel/vmlinux.lds.S
index 6c693a9d29b6..1d6eef4b6976 100644
--- a/arch/arc/kernel/vmlinux.lds.S
+++ b/arch/arc/kernel/vmlinux.lds.S
@@ -118,8 +118,6 @@ SECTIONS
 	/DISCARD/ : {	*(.eh_frame) }
 #endif
 
-	NOTES
-
 	. = ALIGN(PAGE_SIZE);
 	_end = . ;
 
diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
index 8c74037ade22..d2a9651c24ad 100644
--- a/arch/arm/kernel/vmlinux-xip.lds.S
+++ b/arch/arm/kernel/vmlinux-xip.lds.S
@@ -70,8 +70,6 @@ SECTIONS
 	ARM_UNWIND_SECTIONS
 #endif
 
-	NOTES
-
 	_etext = .;			/* End of text and rodata section */
 
 	ARM_VECTORS
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 23150c0f0f4d..068db6860867 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -81,8 +81,6 @@ SECTIONS
 	ARM_UNWIND_SECTIONS
 #endif
 
-	NOTES
-
 #ifdef CONFIG_STRICT_KERNEL_RWX
 	. = ALIGN(1<<SECTION_SHIFT);
 #else
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 7fa008374907..5cf9424485d5 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -137,7 +137,6 @@ SECTIONS
 
 	RO_DATA(PAGE_SIZE)		/* everything from this point to     */
 	EXCEPTION_TABLE(8)		/* __init_begin will be marked RO NX */
-	NOTES
 
 	. = ALIGN(PAGE_SIZE);
 	idmap_pg_dir = .;
diff --git a/arch/c6x/kernel/vmlinux.lds.S b/arch/c6x/kernel/vmlinux.lds.S
index 584bab2bace6..d6e3802536b3 100644
--- a/arch/c6x/kernel/vmlinux.lds.S
+++ b/arch/c6x/kernel/vmlinux.lds.S
@@ -81,7 +81,6 @@ SECTIONS
 	}
 
 	EXCEPTION_TABLE(16)
-	NOTES
 
 	RO_DATA_SECTION(PAGE_SIZE)
 	.const :
diff --git a/arch/csky/kernel/vmlinux.lds.S b/arch/csky/kernel/vmlinux.lds.S
index ae7961b973f2..75dd31412242 100644
--- a/arch/csky/kernel/vmlinux.lds.S
+++ b/arch/csky/kernel/vmlinux.lds.S
@@ -53,7 +53,6 @@ SECTIONS
 	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	_edata = .;
 
-	NOTES
 	EXCEPTION_TABLE(L1_CACHE_BYTES)
 	BSS_SECTION(L1_CACHE_BYTES, PAGE_SIZE, L1_CACHE_BYTES)
 	VBR_BASE
diff --git a/arch/h8300/kernel/vmlinux.lds.S b/arch/h8300/kernel/vmlinux.lds.S
index 49f716c0a1df..88776e785245 100644
--- a/arch/h8300/kernel/vmlinux.lds.S
+++ b/arch/h8300/kernel/vmlinux.lds.S
@@ -38,7 +38,6 @@ SECTIONS
 	_etext = . ;
 	}
 	EXCEPTION_TABLE(16)
-	NOTES
 	RO_DATA_SECTION(4)
 	ROMEND = .;
 #if defined(CONFIG_ROMKERNEL)
diff --git a/arch/hexagon/kernel/vmlinux.lds.S b/arch/hexagon/kernel/vmlinux.lds.S
index 78f2418e97c8..6a6e8fc422ee 100644
--- a/arch/hexagon/kernel/vmlinux.lds.S
+++ b/arch/hexagon/kernel/vmlinux.lds.S
@@ -54,7 +54,6 @@ SECTIONS
 	_edata = .;
 
 	EXCEPTION_TABLE(16)
-	NOTES
 
 	BSS_SECTION(_PAGE_SIZE, _PAGE_SIZE, _PAGE_SIZE)
 
diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index fdcc992ab360..ad3578924589 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -70,8 +70,6 @@ SECTIONS {
 	/*
 	 * Read-only data
 	 */
-	NOTES
-
 	EXCEPTION_TABLE(16)
 
 	/* MCA table */
diff --git a/arch/microblaze/kernel/vmlinux.lds.S b/arch/microblaze/kernel/vmlinux.lds.S
index e1f3e8741292..d008e50bb212 100644
--- a/arch/microblaze/kernel/vmlinux.lds.S
+++ b/arch/microblaze/kernel/vmlinux.lds.S
@@ -53,7 +53,6 @@ SECTIONS {
 	. = ALIGN(16);
 	RODATA
 	EXCEPTION_TABLE(16)
-	NOTES
 
 	/*
 	 * sdata2 section can go anywhere, but must be word aligned
diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
index 6a22f531d815..91e566defc16 100644
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -81,8 +81,6 @@ SECTIONS
 		__stop___dbe_table = .;
 	}
 
-	NOTES
-
 	_sdata = .;			/* Start of data section */
 	RODATA
 
diff --git a/arch/nds32/kernel/vmlinux.lds.S b/arch/nds32/kernel/vmlinux.lds.S
index 9e90f30a181d..c4f1c5a604c3 100644
--- a/arch/nds32/kernel/vmlinux.lds.S
+++ b/arch/nds32/kernel/vmlinux.lds.S
@@ -58,7 +58,6 @@ SECTIONS
 	_edata  =  .;
 
 	EXCEPTION_TABLE(16)
-	NOTES
 	BSS_SECTION(4, 4, 4)
 	_end = .;
 
diff --git a/arch/nios2/kernel/vmlinux.lds.S b/arch/nios2/kernel/vmlinux.lds.S
index 6ad64f14617d..20e4078b3477 100644
--- a/arch/nios2/kernel/vmlinux.lds.S
+++ b/arch/nios2/kernel/vmlinux.lds.S
@@ -58,7 +58,6 @@ SECTIONS
 
 	STABS_DEBUG
 	DWARF_DEBUG
-	NOTES
 
 	DISCARDS
 }
diff --git a/arch/openrisc/kernel/vmlinux.lds.S b/arch/openrisc/kernel/vmlinux.lds.S
index 2e2c72c157f3..142c51c994f5 100644
--- a/arch/openrisc/kernel/vmlinux.lds.S
+++ b/arch/openrisc/kernel/vmlinux.lds.S
@@ -79,7 +79,6 @@ SECTIONS
         _edata  =  .;
 
 	EXCEPTION_TABLE(4)
-	NOTES
 
 	/* Init code and data */
 	. = ALIGN(PAGE_SIZE);
diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S
index 99cd24f2ea01..168d12b2ebb8 100644
--- a/arch/parisc/kernel/vmlinux.lds.S
+++ b/arch/parisc/kernel/vmlinux.lds.S
@@ -131,7 +131,6 @@ SECTIONS
 
 	/* RO because of BUILDTIME_EXTABLE_SORT */
 	EXCEPTION_TABLE(8)
-	NOTES
 
 	/* unwind info */
 	.PARISC.unwind : {
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 4f19d814d592..4e7cec088c8b 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -164,8 +164,6 @@ SECTIONS
 #endif
 	EXCEPTION_TABLE(0)
 
-	NOTES
-
 /*
  * Init sections discarded at runtime
  */
diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S
index 23cd1a9e52a1..df5229c4034d 100644
--- a/arch/riscv/kernel/vmlinux.lds.S
+++ b/arch/riscv/kernel/vmlinux.lds.S
@@ -69,7 +69,6 @@ SECTIONS
 	BSS_SECTION(PAGE_SIZE, PAGE_SIZE, 0)
 
 	EXCEPTION_TABLE(0x10)
-	NOTES
 
 	.rel.dyn : {
 		*(.rel.dyn*)
diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index f88eedeb915a..beb4df053e20 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -52,8 +52,6 @@ SECTIONS
 		_etext = .;		/* End of text section */
 	} :text = 0x0700
 
-	NOTES
-
 	RO_DATA_SECTION(PAGE_SIZE)
 
 	. = ALIGN(PAGE_SIZE);
diff --git a/arch/sh/kernel/vmlinux.lds.S b/arch/sh/kernel/vmlinux.lds.S
index 77a59d8c6b4d..fef39054cc70 100644
--- a/arch/sh/kernel/vmlinux.lds.S
+++ b/arch/sh/kernel/vmlinux.lds.S
@@ -48,7 +48,6 @@ SECTIONS
 	} = 0x0009
 
 	EXCEPTION_TABLE(16)
-	NOTES
 
 	_sdata = .;
 	RO_DATA(PAGE_SIZE)
diff --git a/arch/sparc/kernel/vmlinux.lds.S b/arch/sparc/kernel/vmlinux.lds.S
index 61afd787bd0c..8929fbc35a80 100644
--- a/arch/sparc/kernel/vmlinux.lds.S
+++ b/arch/sparc/kernel/vmlinux.lds.S
@@ -78,7 +78,6 @@ SECTIONS
 		__stop___fixup = .;
 	}
 	EXCEPTION_TABLE(16)
-	NOTES
 
 	. = ALIGN(PAGE_SIZE);
 	__init_begin = ALIGN(PAGE_SIZE);
diff --git a/arch/um/include/asm/common.lds.S b/arch/um/include/asm/common.lds.S
index 4049f2c46387..a24b284f5135 100644
--- a/arch/um/include/asm/common.lds.S
+++ b/arch/um/include/asm/common.lds.S
@@ -16,7 +16,6 @@
   PROVIDE (_unprotected_end = .);
 
   . = ALIGN(4096);
-  NOTES
   EXCEPTION_TABLE(0)
 
   BUG_TABLE
diff --git a/arch/unicore32/kernel/vmlinux.lds.S b/arch/unicore32/kernel/vmlinux.lds.S
index 7abf90537cd5..78c4c56057b0 100644
--- a/arch/unicore32/kernel/vmlinux.lds.S
+++ b/arch/unicore32/kernel/vmlinux.lds.S
@@ -48,7 +48,6 @@ SECTIONS
 	_edata = .;
 
 	EXCEPTION_TABLE(L1_CACHE_BYTES)
-	NOTES
 
 	BSS_SECTION(0, 0, 0)
 	_end = .;
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 8be25b09c2b7..41362e90142d 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -148,8 +148,6 @@ SECTIONS
 		_etext = .;
 	} :text = 0x9090
 
-	NOTES
-
 	EXCEPTION_TABLE(16)
 
 	/* .text should occupy whole number of pages */
diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S
index 943f10639a93..a0a843745695 100644
--- a/arch/xtensa/kernel/vmlinux.lds.S
+++ b/arch/xtensa/kernel/vmlinux.lds.S
@@ -131,7 +131,6 @@ SECTIONS
   .fixup   : { *(.fixup) }
 
   EXCEPTION_TABLE(16)
-  NOTES
   /* Data section */
 
   _sdata = .;
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 6a0a657dfdb4..3a4c1cb971da 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -28,7 +28,6 @@
  *	_edata = .;
  *
  *	EXCEPTION_TABLE(...)
- *	NOTES
  *
  *	BSS_SECTION(0, 0, 0)
  *	_end = .;
@@ -507,10 +506,12 @@
 		__start___modver = .;					\
 		KEEP(*(__modver))					\
 		__stop___modver = .;					\
-		. = ALIGN((align));					\
-		__end_rodata = .;					\
 	}								\
-	. = ALIGN((align));
+									\
+	NOTES								\
+									\
+	. = ALIGN((align));						\
+	__end_rodata = .;
 
 /* RODATA & RO_DATA provided for backward compatibility.
  * All archs are supposed to use RO_DATA() */
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 11/29] vmlinux.lds.h: Replace RODATA with RO_DATA
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (9 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 10/29] vmlinux.lds.h: Move NOTES into RO_DATA Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 12/29] vmlinux.lds.h: Replace RO_DATA_SECTION " Kees Cook
                   ` (18 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

There's no reason to keep the RODATA macro: just replace the callers
with the expected RO_DATA macro.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/alpha/kernel/vmlinux.lds.S      | 2 +-
 arch/ia64/kernel/vmlinux.lds.S       | 2 +-
 arch/microblaze/kernel/vmlinux.lds.S | 2 +-
 arch/mips/kernel/vmlinux.lds.S       | 2 +-
 arch/um/include/asm/common.lds.S     | 2 +-
 arch/xtensa/kernel/vmlinux.lds.S     | 2 +-
 include/asm-generic/vmlinux.lds.h    | 4 +---
 7 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/arch/alpha/kernel/vmlinux.lds.S b/arch/alpha/kernel/vmlinux.lds.S
index bf28043485f6..af411817dd7d 100644
--- a/arch/alpha/kernel/vmlinux.lds.S
+++ b/arch/alpha/kernel/vmlinux.lds.S
@@ -34,7 +34,7 @@ SECTIONS
 	swapper_pg_dir = SWAPPER_PGD;
 	_etext = .;	/* End of text section */
 
-	RODATA
+	RO_DATA(4096)
 	EXCEPTION_TABLE(16)
 
 	/* Will be freed after init */
diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index ad3578924589..0d86fc8e88d5 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -104,7 +104,7 @@ SECTIONS {
 	code_continues2 : {
 	} :text
 
-	RODATA
+	RO_DATA(4096)
 
 	.opd : AT(ADDR(.opd) - LOAD_OFFSET) {
 		__start_opd = .;
diff --git a/arch/microblaze/kernel/vmlinux.lds.S b/arch/microblaze/kernel/vmlinux.lds.S
index d008e50bb212..2299694748ea 100644
--- a/arch/microblaze/kernel/vmlinux.lds.S
+++ b/arch/microblaze/kernel/vmlinux.lds.S
@@ -51,7 +51,7 @@ SECTIONS {
 	}
 
 	. = ALIGN(16);
-	RODATA
+	RO_DATA(4096)
 	EXCEPTION_TABLE(16)
 
 	/*
diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
index 91e566defc16..a5f00ec73ea6 100644
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -82,7 +82,7 @@ SECTIONS
 	}
 
 	_sdata = .;			/* Start of data section */
-	RODATA
+	RO_DATA(4096)
 
 	/* writeable */
 	.data : {	/* Data */
diff --git a/arch/um/include/asm/common.lds.S b/arch/um/include/asm/common.lds.S
index a24b284f5135..eca6c452a41b 100644
--- a/arch/um/include/asm/common.lds.S
+++ b/arch/um/include/asm/common.lds.S
@@ -9,7 +9,7 @@
   _sdata = .;
   PROVIDE (sdata = .);
 
-  RODATA
+  RO_DATA(4096)
 
   .unprotected : { *(.unprotected) }
   . = ALIGN(4096);
diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S
index a0a843745695..b97e5798b9cf 100644
--- a/arch/xtensa/kernel/vmlinux.lds.S
+++ b/arch/xtensa/kernel/vmlinux.lds.S
@@ -124,7 +124,7 @@ SECTIONS
 
   . = ALIGN(16);
 
-  RODATA
+  RO_DATA(4096)
 
   /*  Relocation table */
 
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 3a4c1cb971da..9520dede6c7a 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -513,9 +513,7 @@
 	. = ALIGN((align));						\
 	__end_rodata = .;
 
-/* RODATA & RO_DATA provided for backward compatibility.
- * All archs are supposed to use RO_DATA() */
-#define RODATA          RO_DATA_SECTION(4096)
+/* All archs are supposed to use RO_DATA() */
 #define RO_DATA(align)  RO_DATA_SECTION(align)
 
 /*
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 12/29] vmlinux.lds.h: Replace RO_DATA_SECTION with RO_DATA
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (10 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 11/29] vmlinux.lds.h: Replace RODATA with RO_DATA Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 13/29] vmlinux.lds.h: Replace RW_DATA_SECTION with RW_DATA Kees Cook
                   ` (17 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

This finishes renaming RO_DATA_SECTION to RO_DATA. (Calling this a
"section" is a lie, since it's multiple sections and section flags cannot
be applied to the macro.)

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/arc/kernel/vmlinux.lds.S       | 2 +-
 arch/c6x/kernel/vmlinux.lds.S       | 2 +-
 arch/csky/kernel/vmlinux.lds.S      | 2 +-
 arch/h8300/kernel/vmlinux.lds.S     | 2 +-
 arch/hexagon/kernel/vmlinux.lds.S   | 2 +-
 arch/m68k/kernel/vmlinux-nommu.lds  | 2 +-
 arch/nds32/kernel/vmlinux.lds.S     | 2 +-
 arch/nios2/kernel/vmlinux.lds.S     | 2 +-
 arch/openrisc/kernel/vmlinux.lds.S  | 4 ++--
 arch/parisc/kernel/vmlinux.lds.S    | 4 ++--
 arch/riscv/kernel/vmlinux.lds.S     | 2 +-
 arch/s390/kernel/vmlinux.lds.S      | 2 +-
 arch/unicore32/kernel/vmlinux.lds.S | 2 +-
 include/asm-generic/vmlinux.lds.h   | 7 ++-----
 14 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/arch/arc/kernel/vmlinux.lds.S b/arch/arc/kernel/vmlinux.lds.S
index 1d6eef4b6976..7d1d27066deb 100644
--- a/arch/arc/kernel/vmlinux.lds.S
+++ b/arch/arc/kernel/vmlinux.lds.S
@@ -95,7 +95,7 @@ SECTIONS
 	_etext = .;
 
 	_sdata = .;
-	RO_DATA_SECTION(PAGE_SIZE)
+	RO_DATA(PAGE_SIZE)
 
 	/*
 	 * 1. this is .data essentially
diff --git a/arch/c6x/kernel/vmlinux.lds.S b/arch/c6x/kernel/vmlinux.lds.S
index d6e3802536b3..a3547f9d415b 100644
--- a/arch/c6x/kernel/vmlinux.lds.S
+++ b/arch/c6x/kernel/vmlinux.lds.S
@@ -82,7 +82,7 @@ SECTIONS
 
 	EXCEPTION_TABLE(16)
 
-	RO_DATA_SECTION(PAGE_SIZE)
+	RO_DATA(PAGE_SIZE)
 	.const :
 	{
 		*(.const .const.* .gnu.linkonce.r.*)
diff --git a/arch/csky/kernel/vmlinux.lds.S b/arch/csky/kernel/vmlinux.lds.S
index 75dd31412242..8598bd7a7bcd 100644
--- a/arch/csky/kernel/vmlinux.lds.S
+++ b/arch/csky/kernel/vmlinux.lds.S
@@ -49,7 +49,7 @@ SECTIONS
 
 
 	_sdata = .;
-	RO_DATA_SECTION(PAGE_SIZE)
+	RO_DATA(PAGE_SIZE)
 	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	_edata = .;
 
diff --git a/arch/h8300/kernel/vmlinux.lds.S b/arch/h8300/kernel/vmlinux.lds.S
index 88776e785245..d3247d33b115 100644
--- a/arch/h8300/kernel/vmlinux.lds.S
+++ b/arch/h8300/kernel/vmlinux.lds.S
@@ -38,7 +38,7 @@ SECTIONS
 	_etext = . ;
 	}
 	EXCEPTION_TABLE(16)
-	RO_DATA_SECTION(4)
+	RO_DATA(4)
 	ROMEND = .;
 #if defined(CONFIG_ROMKERNEL)
 	. = RAMTOP;
diff --git a/arch/hexagon/kernel/vmlinux.lds.S b/arch/hexagon/kernel/vmlinux.lds.S
index 6a6e8fc422ee..0145251fa317 100644
--- a/arch/hexagon/kernel/vmlinux.lds.S
+++ b/arch/hexagon/kernel/vmlinux.lds.S
@@ -50,7 +50,7 @@ SECTIONS
 
 	_sdata = .;
 		RW_DATA_SECTION(32,PAGE_SIZE,_THREAD_SIZE)
-		RO_DATA_SECTION(PAGE_SIZE)
+		RO_DATA(PAGE_SIZE)
 	_edata = .;
 
 	EXCEPTION_TABLE(16)
diff --git a/arch/m68k/kernel/vmlinux-nommu.lds b/arch/m68k/kernel/vmlinux-nommu.lds
index cf6edda38971..de80f8b8ae78 100644
--- a/arch/m68k/kernel/vmlinux-nommu.lds
+++ b/arch/m68k/kernel/vmlinux-nommu.lds
@@ -60,7 +60,7 @@ SECTIONS {
 #endif
 
 	_sdata = .;
-	RO_DATA_SECTION(PAGE_SIZE)
+	RO_DATA(PAGE_SIZE)
 	RW_DATA_SECTION(16, PAGE_SIZE, THREAD_SIZE)
 	_edata = .;
 
diff --git a/arch/nds32/kernel/vmlinux.lds.S b/arch/nds32/kernel/vmlinux.lds.S
index c4f1c5a604c3..10ff570ba95b 100644
--- a/arch/nds32/kernel/vmlinux.lds.S
+++ b/arch/nds32/kernel/vmlinux.lds.S
@@ -53,7 +53,7 @@ SECTIONS
 	_etext = .;			/* End of text and rodata section */
 
 	_sdata = .;
-	RO_DATA_SECTION(PAGE_SIZE)
+	RO_DATA(PAGE_SIZE)
 	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	_edata  =  .;
 
diff --git a/arch/nios2/kernel/vmlinux.lds.S b/arch/nios2/kernel/vmlinux.lds.S
index 20e4078b3477..318804a2c7a1 100644
--- a/arch/nios2/kernel/vmlinux.lds.S
+++ b/arch/nios2/kernel/vmlinux.lds.S
@@ -49,7 +49,7 @@ SECTIONS
 	__init_end = .;
 
 	_sdata = .;
-	RO_DATA_SECTION(PAGE_SIZE)
+	RO_DATA(PAGE_SIZE)
 	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	_edata = .;
 
diff --git a/arch/openrisc/kernel/vmlinux.lds.S b/arch/openrisc/kernel/vmlinux.lds.S
index 142c51c994f5..f73e0d3ea09f 100644
--- a/arch/openrisc/kernel/vmlinux.lds.S
+++ b/arch/openrisc/kernel/vmlinux.lds.S
@@ -67,8 +67,8 @@ SECTIONS
 
 	_sdata = .;
 
-	/* Page alignment required for RO_DATA_SECTION */
-	RO_DATA_SECTION(PAGE_SIZE)
+	/* Page alignment required for RO_DATA */
+	RO_DATA(PAGE_SIZE)
 	_e_kernel_ro = .;
 
 	/* Whatever comes after _e_kernel_ro had better be page-aligend, too */
diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S
index 168d12b2ebb8..e1c563c7dca1 100644
--- a/arch/parisc/kernel/vmlinux.lds.S
+++ b/arch/parisc/kernel/vmlinux.lds.S
@@ -109,7 +109,7 @@ SECTIONS
 	_sdata = .;
 
 	/* Architecturally we need to keep __gp below 0x1000000 and thus
-	 * in front of RO_DATA_SECTION() which stores lots of tracepoint
+	 * in front of RO_DATA() which stores lots of tracepoint
 	 * and ftrace symbols. */
 #ifdef CONFIG_64BIT
 	. = ALIGN(16);
@@ -127,7 +127,7 @@ SECTIONS
 	}
 #endif
 
-	RO_DATA_SECTION(8)
+	RO_DATA(8)
 
 	/* RO because of BUILDTIME_EXTABLE_SORT */
 	EXCEPTION_TABLE(8)
diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S
index df5229c4034d..66dc17d24dd9 100644
--- a/arch/riscv/kernel/vmlinux.lds.S
+++ b/arch/riscv/kernel/vmlinux.lds.S
@@ -52,7 +52,7 @@ SECTIONS
 
 	/* Start of data section */
 	_sdata = .;
-	RO_DATA_SECTION(L1_CACHE_BYTES)
+	RO_DATA(L1_CACHE_BYTES)
 	.srodata : {
 		*(.srodata*)
 	}
diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index beb4df053e20..b33c4823f8b5 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -52,7 +52,7 @@ SECTIONS
 		_etext = .;		/* End of text section */
 	} :text = 0x0700
 
-	RO_DATA_SECTION(PAGE_SIZE)
+	RO_DATA(PAGE_SIZE)
 
 	. = ALIGN(PAGE_SIZE);
 	_sdata = .;		/* Start of data section */
diff --git a/arch/unicore32/kernel/vmlinux.lds.S b/arch/unicore32/kernel/vmlinux.lds.S
index 78c4c56057b0..367c80313bec 100644
--- a/arch/unicore32/kernel/vmlinux.lds.S
+++ b/arch/unicore32/kernel/vmlinux.lds.S
@@ -43,7 +43,7 @@ SECTIONS
 	_etext = .;
 
 	_sdata = .;
-	RO_DATA_SECTION(PAGE_SIZE)
+	RO_DATA(PAGE_SIZE)
 	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	_edata = .;
 
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 9520dede6c7a..cdff8ba42d4d 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -23,7 +23,7 @@
  *	_etext = .;
  *
  *      _sdata = .;
- *	RO_DATA_SECTION(PAGE_SIZE)
+ *	RO_DATA(PAGE_SIZE)
  *	RW_DATA_SECTION(...)
  *	_edata = .;
  *
@@ -358,7 +358,7 @@
 /*
  * Read only Data
  */
-#define RO_DATA_SECTION(align)						\
+#define RO_DATA(align)							\
 	. = ALIGN((align));						\
 	.rodata           : AT(ADDR(.rodata) - LOAD_OFFSET) {		\
 		__start_rodata = .;					\
@@ -513,9 +513,6 @@
 	. = ALIGN((align));						\
 	__end_rodata = .;
 
-/* All archs are supposed to use RO_DATA() */
-#define RO_DATA(align)  RO_DATA_SECTION(align)
-
 /*
  * .text section. Map to function alignment to avoid address changes
  * during second ld run in second ld pass when generating System.map
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 13/29] vmlinux.lds.h: Replace RW_DATA_SECTION with RW_DATA
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (11 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 12/29] vmlinux.lds.h: Replace RO_DATA_SECTION " Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA Kees Cook
                   ` (16 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

This renames RW_DATA_SECTION to RW_DATA. (Calling this a "section" is
a lie, since it's multiple sections and section flags cannot be applied
to the macro.)

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/alpha/kernel/vmlinux.lds.S      | 2 +-
 arch/arc/kernel/vmlinux.lds.S        | 2 +-
 arch/arm/kernel/vmlinux-xip.lds.S    | 2 +-
 arch/arm/kernel/vmlinux.lds.S        | 2 +-
 arch/arm64/kernel/vmlinux.lds.S      | 2 +-
 arch/csky/kernel/vmlinux.lds.S       | 2 +-
 arch/h8300/kernel/vmlinux.lds.S      | 2 +-
 arch/hexagon/kernel/vmlinux.lds.S    | 2 +-
 arch/m68k/kernel/vmlinux-nommu.lds   | 2 +-
 arch/m68k/kernel/vmlinux-std.lds     | 2 +-
 arch/m68k/kernel/vmlinux-sun3.lds    | 2 +-
 arch/microblaze/kernel/vmlinux.lds.S | 2 +-
 arch/nds32/kernel/vmlinux.lds.S      | 2 +-
 arch/nios2/kernel/vmlinux.lds.S      | 2 +-
 arch/openrisc/kernel/vmlinux.lds.S   | 2 +-
 arch/parisc/kernel/vmlinux.lds.S     | 2 +-
 arch/riscv/kernel/vmlinux.lds.S      | 2 +-
 arch/s390/kernel/vmlinux.lds.S       | 2 +-
 arch/sh/kernel/vmlinux.lds.S         | 2 +-
 arch/sparc/kernel/vmlinux.lds.S      | 2 +-
 arch/unicore32/kernel/vmlinux.lds.S  | 2 +-
 arch/xtensa/kernel/vmlinux.lds.S     | 2 +-
 include/asm-generic/vmlinux.lds.h    | 4 ++--
 23 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/arch/alpha/kernel/vmlinux.lds.S b/arch/alpha/kernel/vmlinux.lds.S
index af411817dd7d..edc45f45523b 100644
--- a/arch/alpha/kernel/vmlinux.lds.S
+++ b/arch/alpha/kernel/vmlinux.lds.S
@@ -50,7 +50,7 @@ SECTIONS
 
 	_sdata = .;	/* Start of rw data section */
 	_data = .;
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 
 	.got : {
 		*(.got)
diff --git a/arch/arc/kernel/vmlinux.lds.S b/arch/arc/kernel/vmlinux.lds.S
index 7d1d27066deb..54139a6f469b 100644
--- a/arch/arc/kernel/vmlinux.lds.S
+++ b/arch/arc/kernel/vmlinux.lds.S
@@ -101,7 +101,7 @@ SECTIONS
 	 * 1. this is .data essentially
 	 * 2. THREAD_SIZE for init.task, must be kernel-stk sz aligned
 	 */
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 
 	_edata = .;
 
diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
index d2a9651c24ad..21b8b271c80d 100644
--- a/arch/arm/kernel/vmlinux-xip.lds.S
+++ b/arch/arm/kernel/vmlinux-xip.lds.S
@@ -112,7 +112,7 @@ SECTIONS
 
 	. = ALIGN(THREAD_SIZE);
 	_sdata = .;
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	.data.ro_after_init : AT(ADDR(.data.ro_after_init) - LOAD_OFFSET) {
 		*(.data..ro_after_init)
 	}
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 068db6860867..319ccb10846a 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -141,7 +141,7 @@ SECTIONS
 	__init_end = .;
 
 	_sdata = .;
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	_edata = .;
 
 	BSS_SECTION(0, 0, 0)
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 5cf9424485d5..81d94e371c95 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -205,7 +205,7 @@ SECTIONS
 
 	_data = .;
 	_sdata = .;
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_ALIGN)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_ALIGN)
 
 	/*
 	 * Data written with the MMU off but read with the MMU on requires
diff --git a/arch/csky/kernel/vmlinux.lds.S b/arch/csky/kernel/vmlinux.lds.S
index 8598bd7a7bcd..2ff37beaf2bf 100644
--- a/arch/csky/kernel/vmlinux.lds.S
+++ b/arch/csky/kernel/vmlinux.lds.S
@@ -50,7 +50,7 @@ SECTIONS
 
 	_sdata = .;
 	RO_DATA(PAGE_SIZE)
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	_edata = .;
 
 	EXCEPTION_TABLE(L1_CACHE_BYTES)
diff --git a/arch/h8300/kernel/vmlinux.lds.S b/arch/h8300/kernel/vmlinux.lds.S
index d3247d33b115..2ac7bdcd2fe0 100644
--- a/arch/h8300/kernel/vmlinux.lds.S
+++ b/arch/h8300/kernel/vmlinux.lds.S
@@ -47,7 +47,7 @@ SECTIONS
 #endif
 	_sdata = . ;
 	__data_start = . ;
-	RW_DATA_SECTION(0, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(0, PAGE_SIZE, THREAD_SIZE)
 #if defined(CONFIG_ROMKERNEL)
 #undef ADDR
 #endif
diff --git a/arch/hexagon/kernel/vmlinux.lds.S b/arch/hexagon/kernel/vmlinux.lds.S
index 0145251fa317..0ca2471ddb9f 100644
--- a/arch/hexagon/kernel/vmlinux.lds.S
+++ b/arch/hexagon/kernel/vmlinux.lds.S
@@ -49,7 +49,7 @@ SECTIONS
 	INIT_DATA_SECTION(PAGE_SIZE)
 
 	_sdata = .;
-		RW_DATA_SECTION(32,PAGE_SIZE,_THREAD_SIZE)
+		RW_DATA(32,PAGE_SIZE,_THREAD_SIZE)
 		RO_DATA(PAGE_SIZE)
 	_edata = .;
 
diff --git a/arch/m68k/kernel/vmlinux-nommu.lds b/arch/m68k/kernel/vmlinux-nommu.lds
index de80f8b8ae78..7b975420c3d9 100644
--- a/arch/m68k/kernel/vmlinux-nommu.lds
+++ b/arch/m68k/kernel/vmlinux-nommu.lds
@@ -61,7 +61,7 @@ SECTIONS {
 
 	_sdata = .;
 	RO_DATA(PAGE_SIZE)
-	RW_DATA_SECTION(16, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(16, PAGE_SIZE, THREAD_SIZE)
 	_edata = .;
 
 	EXCEPTION_TABLE(16)
diff --git a/arch/m68k/kernel/vmlinux-std.lds b/arch/m68k/kernel/vmlinux-std.lds
index 625a5785804f..6e7eb49ed985 100644
--- a/arch/m68k/kernel/vmlinux-std.lds
+++ b/arch/m68k/kernel/vmlinux-std.lds
@@ -33,7 +33,7 @@ SECTIONS
 
   RODATA
 
-  RW_DATA_SECTION(16, PAGE_SIZE, THREAD_SIZE)
+  RW_DATA(16, PAGE_SIZE, THREAD_SIZE)
 
   BSS_SECTION(0, 0, 0)
 
diff --git a/arch/m68k/kernel/vmlinux-sun3.lds b/arch/m68k/kernel/vmlinux-sun3.lds
index 9868270b0984..1a0ad6b6dd8c 100644
--- a/arch/m68k/kernel/vmlinux-sun3.lds
+++ b/arch/m68k/kernel/vmlinux-sun3.lds
@@ -30,7 +30,7 @@ SECTIONS
 
   EXCEPTION_TABLE(16) :data
   _sdata = .;			/* Start of rw data section */
-  RW_DATA_SECTION(16, PAGE_SIZE, THREAD_SIZE) :data
+  RW_DATA(16, PAGE_SIZE, THREAD_SIZE) :data
   /* End of data goes *here* so that freeing init code works properly. */
   _edata = .;
   NOTES
diff --git a/arch/microblaze/kernel/vmlinux.lds.S b/arch/microblaze/kernel/vmlinux.lds.S
index 2299694748ea..b8efb08204a1 100644
--- a/arch/microblaze/kernel/vmlinux.lds.S
+++ b/arch/microblaze/kernel/vmlinux.lds.S
@@ -69,7 +69,7 @@ SECTIONS {
 	}
 
 	_sdata = . ;
-	RW_DATA_SECTION(32, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(32, PAGE_SIZE, THREAD_SIZE)
 	_edata = . ;
 
 	/* Under the microblaze ABI, .sdata and .sbss must be contiguous */
diff --git a/arch/nds32/kernel/vmlinux.lds.S b/arch/nds32/kernel/vmlinux.lds.S
index 10ff570ba95b..f679d3397436 100644
--- a/arch/nds32/kernel/vmlinux.lds.S
+++ b/arch/nds32/kernel/vmlinux.lds.S
@@ -54,7 +54,7 @@ SECTIONS
 
 	_sdata = .;
 	RO_DATA(PAGE_SIZE)
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	_edata  =  .;
 
 	EXCEPTION_TABLE(16)
diff --git a/arch/nios2/kernel/vmlinux.lds.S b/arch/nios2/kernel/vmlinux.lds.S
index 318804a2c7a1..c55a7cfa1075 100644
--- a/arch/nios2/kernel/vmlinux.lds.S
+++ b/arch/nios2/kernel/vmlinux.lds.S
@@ -50,7 +50,7 @@ SECTIONS
 
 	_sdata = .;
 	RO_DATA(PAGE_SIZE)
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	_edata = .;
 
 	BSS_SECTION(0, 0, 0)
diff --git a/arch/openrisc/kernel/vmlinux.lds.S b/arch/openrisc/kernel/vmlinux.lds.S
index f73e0d3ea09f..60449fd7f16f 100644
--- a/arch/openrisc/kernel/vmlinux.lds.S
+++ b/arch/openrisc/kernel/vmlinux.lds.S
@@ -74,7 +74,7 @@ SECTIONS
 	/* Whatever comes after _e_kernel_ro had better be page-aligend, too */
 
 	/* 32 here is cacheline size... recheck this */
-	RW_DATA_SECTION(32, PAGE_SIZE, PAGE_SIZE)
+	RW_DATA(32, PAGE_SIZE, PAGE_SIZE)
 
         _edata  =  .;
 
diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S
index e1c563c7dca1..12b3d7d5e9e4 100644
--- a/arch/parisc/kernel/vmlinux.lds.S
+++ b/arch/parisc/kernel/vmlinux.lds.S
@@ -148,7 +148,7 @@ SECTIONS
 	data_start = .;
 
 	/* Data */
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, PAGE_SIZE)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, PAGE_SIZE)
 
 	/* PA-RISC locks requires 16-byte alignment */
 	. = ALIGN(16);
diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S
index 66dc17d24dd9..12f42f96d46e 100644
--- a/arch/riscv/kernel/vmlinux.lds.S
+++ b/arch/riscv/kernel/vmlinux.lds.S
@@ -57,7 +57,7 @@ SECTIONS
 		*(.srodata*)
 	}
 
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	.sdata : {
 		__global_pointer$ = . + 0x800;
 		*(.sdata*)
diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index b33c4823f8b5..37695499717d 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -67,7 +67,7 @@ SECTIONS
 	. = ALIGN(PAGE_SIZE);
 	__end_ro_after_init = .;
 
-	RW_DATA_SECTION(0x100, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(0x100, PAGE_SIZE, THREAD_SIZE)
 	BOOT_DATA_PRESERVED
 
 	_edata = .;		/* End of data section */
diff --git a/arch/sh/kernel/vmlinux.lds.S b/arch/sh/kernel/vmlinux.lds.S
index fef39054cc70..c60b19958c35 100644
--- a/arch/sh/kernel/vmlinux.lds.S
+++ b/arch/sh/kernel/vmlinux.lds.S
@@ -51,7 +51,7 @@ SECTIONS
 
 	_sdata = .;
 	RO_DATA(PAGE_SIZE)
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	_edata = .;
 
 	DWARF_EH_FRAME
diff --git a/arch/sparc/kernel/vmlinux.lds.S b/arch/sparc/kernel/vmlinux.lds.S
index 8929fbc35a80..7ec79918b566 100644
--- a/arch/sparc/kernel/vmlinux.lds.S
+++ b/arch/sparc/kernel/vmlinux.lds.S
@@ -67,7 +67,7 @@ SECTIONS
 	.data1 : {
 		*(.data1)
 	}
-	RW_DATA_SECTION(SMP_CACHE_BYTES, 0, THREAD_SIZE)
+	RW_DATA(SMP_CACHE_BYTES, 0, THREAD_SIZE)
 
 	/* End of data section */
 	_edata = .;
diff --git a/arch/unicore32/kernel/vmlinux.lds.S b/arch/unicore32/kernel/vmlinux.lds.S
index 367c80313bec..6fb320b337ef 100644
--- a/arch/unicore32/kernel/vmlinux.lds.S
+++ b/arch/unicore32/kernel/vmlinux.lds.S
@@ -44,7 +44,7 @@ SECTIONS
 
 	_sdata = .;
 	RO_DATA(PAGE_SIZE)
-	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 	_edata = .;
 
 	EXCEPTION_TABLE(L1_CACHE_BYTES)
diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S
index b97e5798b9cf..bdbd7c4056c1 100644
--- a/arch/xtensa/kernel/vmlinux.lds.S
+++ b/arch/xtensa/kernel/vmlinux.lds.S
@@ -134,7 +134,7 @@ SECTIONS
   /* Data section */
 
   _sdata = .;
-  RW_DATA_SECTION(XCHAL_ICACHE_LINESIZE, PAGE_SIZE, THREAD_SIZE)
+  RW_DATA(XCHAL_ICACHE_LINESIZE, PAGE_SIZE, THREAD_SIZE)
   _edata = .;
 
   /* Initialization code and data: */
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index cdff8ba42d4d..d57a28786bb8 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -24,7 +24,7 @@
  *
  *      _sdata = .;
  *	RO_DATA(PAGE_SIZE)
- *	RW_DATA_SECTION(...)
+ *	RW_DATA(...)
  *	_edata = .;
  *
  *	EXCEPTION_TABLE(...)
@@ -969,7 +969,7 @@
  * matches the requirement of PAGE_ALIGNED_DATA.
  *
  * use 0 as page_align if page_aligned data is not used */
-#define RW_DATA_SECTION(cacheline, pagealigned, inittask)		\
+#define RW_DATA(cacheline, pagealigned, inittask)			\
 	. = ALIGN(PAGE_SIZE);						\
 	.data : AT(ADDR(.data) - LOAD_OFFSET) {				\
 		INIT_TASK_DATA(inittask)				\
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (12 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 13/29] vmlinux.lds.h: Replace RW_DATA_SECTION with RW_DATA Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-10-01  9:05   ` Will Deacon
  2019-10-10 15:25   ` Borislav Petkov
  2019-09-26 17:55 ` [PATCH 15/29] x86: Actually use _etext for end of text segment Kees Cook
                   ` (15 subsequent siblings)
  29 siblings, 2 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

Many architectures have an EXCEPTION_TABLE that needs only to be
read-only. As such, it should live in RO_DATA. This creates a macro to
identify this case for the architectures that can move EXCEPTION_TABLE
into RO_DATA.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/asm-generic/vmlinux.lds.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index d57a28786bb8..35a6cba39d9f 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -69,6 +69,17 @@
 #define NOTES_HEADERS_RESTORE
 #endif
 
+/*
+ * Some architectures have non-executable read-only exception tables.
+ * They can be added to the RO_DATA segment by specifying their desired
+ * alignment.
+ */
+#ifdef RO_DATA_EXCEPTION_TABLE_ALIGN
+#define RO_DATA_EXCEPTION_TABLE	EXCEPTION_TABLE(RO_DATA_EXCEPTION_TABLE_ALIGN)
+#else
+#define RO_DATA_EXCEPTION_TABLE
+#endif
+
 /* Align . to a 8 byte boundary equals to maximum function alignment. */
 #define ALIGN_FUNCTION()  . = ALIGN(8)
 
@@ -508,6 +519,7 @@
 		__stop___modver = .;					\
 	}								\
 									\
+	RO_DATA_EXCEPTION_TABLE						\
 	NOTES								\
 									\
 	. = ALIGN((align));						\
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 15/29] x86: Actually use _etext for end of text segment
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (13 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 16/29] x86: Move EXCEPTION_TABLE to RO_DATA segment Kees Cook
                   ` (14 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

Various calculations are using the end of the exception table (which
does not need to be executable) as the end of the text segment. Instead,
in preparation for moving the exception table into RO_DATA, move _etext
after the exception table and update the calculations.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/include/asm/sections.h | 1 -
 arch/x86/kernel/vmlinux.lds.S   | 7 +++----
 arch/x86/mm/init_64.c           | 6 +++---
 arch/x86/mm/pti.c               | 2 +-
 4 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/sections.h b/arch/x86/include/asm/sections.h
index 71b32f2570ab..036c360910c5 100644
--- a/arch/x86/include/asm/sections.h
+++ b/arch/x86/include/asm/sections.h
@@ -6,7 +6,6 @@
 #include <asm/extable.h>
 
 extern char __brk_base[], __brk_limit[];
-extern struct exception_table_entry __stop___ex_table[];
 extern char __end_rodata_aligned[];
 
 #if defined(CONFIG_X86_64)
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 41362e90142d..a1a758e25b2b 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -143,15 +143,14 @@ SECTIONS
 		*(.text.__x86.indirect_thunk)
 		__indirect_thunk_end = .;
 #endif
-
-		/* End of text section */
-		_etext = .;
 	} :text = 0x9090
 
 	EXCEPTION_TABLE(16)
 
-	/* .text should occupy whole number of pages */
+	/* End of text section, which should occupy whole number of pages */
+	_etext = .;
 	. = ALIGN(PAGE_SIZE);
+
 	X86_ALIGN_RODATA_BEGIN
 	RO_DATA(PAGE_SIZE)
 	X86_ALIGN_RODATA_END
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index a6b5c653727b..26299e9ce6da 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1263,7 +1263,7 @@ int kernel_set_to_readonly;
 void set_kernel_text_rw(void)
 {
 	unsigned long start = PFN_ALIGN(_text);
-	unsigned long end = PFN_ALIGN(__stop___ex_table);
+	unsigned long end = PFN_ALIGN(_etext);
 
 	if (!kernel_set_to_readonly)
 		return;
@@ -1282,7 +1282,7 @@ void set_kernel_text_rw(void)
 void set_kernel_text_ro(void)
 {
 	unsigned long start = PFN_ALIGN(_text);
-	unsigned long end = PFN_ALIGN(__stop___ex_table);
+	unsigned long end = PFN_ALIGN(_etext);
 
 	if (!kernel_set_to_readonly)
 		return;
@@ -1301,7 +1301,7 @@ void mark_rodata_ro(void)
 	unsigned long start = PFN_ALIGN(_text);
 	unsigned long rodata_start = PFN_ALIGN(__start_rodata);
 	unsigned long end = (unsigned long) &__end_rodata_hpage_align;
-	unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
+	unsigned long text_end = PFN_ALIGN(&_etext);
 	unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
 	unsigned long all_end;
 
diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
index b196524759ec..bd3404fd9d80 100644
--- a/arch/x86/mm/pti.c
+++ b/arch/x86/mm/pti.c
@@ -572,7 +572,7 @@ static void pti_clone_kernel_text(void)
 	 */
 	unsigned long start = PFN_ALIGN(_text);
 	unsigned long end_clone  = (unsigned long)__end_rodata_aligned;
-	unsigned long end_global = PFN_ALIGN((unsigned long)__stop___ex_table);
+	unsigned long end_global = PFN_ALIGN((unsigned long)_etext);
 
 	if (!pti_kernel_image_global_ok())
 		return;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 16/29] x86: Move EXCEPTION_TABLE to RO_DATA segment
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (14 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 15/29] x86: Actually use _etext for end of text segment Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 17/29] alpha: " Kees Cook
                   ` (13 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The exception table was needlessly marked executable. In preparation
for execute-only memory, this moves the table into the RO_DATA segment
via a new macro that can be used by any architectures that want to make
a similar consolidation.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/kernel/vmlinux.lds.S | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index a1a758e25b2b..a5c8571e4967 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -22,6 +22,7 @@
 #endif
 
 #define EMITS_PT_NOTE
+#define RO_DATA_EXCEPTION_TABLE_ALIGN	16
 
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/asm-offsets.h>
@@ -145,8 +146,6 @@ SECTIONS
 #endif
 	} :text = 0x9090
 
-	EXCEPTION_TABLE(16)
-
 	/* End of text section, which should occupy whole number of pages */
 	_etext = .;
 	. = ALIGN(PAGE_SIZE);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 17/29] alpha: Move EXCEPTION_TABLE to RO_DATA segment
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (15 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 16/29] x86: Move EXCEPTION_TABLE to RO_DATA segment Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 18/29] arm64: " Kees Cook
                   ` (12 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The EXCEPTION_TABLE is read-only, so collapse it into RO_DATA.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/alpha/kernel/vmlinux.lds.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/alpha/kernel/vmlinux.lds.S b/arch/alpha/kernel/vmlinux.lds.S
index edc45f45523b..72303827bcb4 100644
--- a/arch/alpha/kernel/vmlinux.lds.S
+++ b/arch/alpha/kernel/vmlinux.lds.S
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 
 #define EMITS_PT_NOTE
+#define RO_DATA_EXCEPTION_TABLE_ALIGN	16
 
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/thread_info.h>
@@ -35,7 +36,6 @@ SECTIONS
 	_etext = .;	/* End of text section */
 
 	RO_DATA(4096)
-	EXCEPTION_TABLE(16)
 
 	/* Will be freed after init */
 	__init_begin = ALIGN(PAGE_SIZE);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 18/29] arm64: Move EXCEPTION_TABLE to RO_DATA segment
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (16 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 17/29] alpha: " Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-10-01  9:03   ` Will Deacon
  2019-09-26 17:55 ` [PATCH 19/29] c6x: " Kees Cook
                   ` (11 subsequent siblings)
  29 siblings, 1 reply; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The EXCEPTION_TABLE is read-only, so collapse it into RO_DATA.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/arm64/kernel/vmlinux.lds.S | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 81d94e371c95..c6ba2eee0ee8 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -5,6 +5,8 @@
  * Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
  */
 
+#define RO_DATA_EXCEPTION_TABLE_ALIGN	8
+
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/cache.h>
 #include <asm/kernel-pgtable.h>
@@ -135,8 +137,8 @@ SECTIONS
 	. = ALIGN(SEGMENT_ALIGN);
 	_etext = .;			/* End of text section */
 
-	RO_DATA(PAGE_SIZE)		/* everything from this point to     */
-	EXCEPTION_TABLE(8)		/* __init_begin will be marked RO NX */
+	/* everything from this point to __init_begin will be marked RO NX */
+	RO_DATA(PAGE_SIZE)
 
 	. = ALIGN(PAGE_SIZE);
 	idmap_pg_dir = .;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 19/29] c6x: Move EXCEPTION_TABLE to RO_DATA segment
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (17 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 18/29] arm64: " Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 20/29] h8300: " Kees Cook
                   ` (10 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The EXCEPTION_TABLE is read-only, so collapse it into RO_DATA.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/c6x/kernel/vmlinux.lds.S | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/c6x/kernel/vmlinux.lds.S b/arch/c6x/kernel/vmlinux.lds.S
index a3547f9d415b..9a09aab63ab3 100644
--- a/arch/c6x/kernel/vmlinux.lds.S
+++ b/arch/c6x/kernel/vmlinux.lds.S
@@ -5,6 +5,9 @@
  *  Copyright (C) 2010, 2011 Texas Instruments Incorporated
  *  Mark Salter <msalter@redhat.com>
  */
+
+#define RO_DATA_EXCEPTION_TABLE_ALIGN	16
+
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/thread_info.h>
 #include <asm/page.h>
@@ -80,8 +83,6 @@ SECTIONS
 		*(.gnu.warning)
 	}
 
-	EXCEPTION_TABLE(16)
-
 	RO_DATA(PAGE_SIZE)
 	.const :
 	{
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 20/29] h8300: Move EXCEPTION_TABLE to RO_DATA segment
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (18 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 19/29] c6x: " Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 21/29] ia64: " Kees Cook
                   ` (9 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The EXCEPTION_TABLE is read-only, so collapse it into RO_DATA.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/h8300/kernel/vmlinux.lds.S | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/h8300/kernel/vmlinux.lds.S b/arch/h8300/kernel/vmlinux.lds.S
index 2ac7bdcd2fe0..aba90398b774 100644
--- a/arch/h8300/kernel/vmlinux.lds.S
+++ b/arch/h8300/kernel/vmlinux.lds.S
@@ -1,4 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+
+#define RO_DATA_EXCEPTION_TABLE_ALIGN	16
+
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/page.h>
 #include <asm/thread_info.h>
@@ -37,7 +40,6 @@ SECTIONS
 #endif
 	_etext = . ;
 	}
-	EXCEPTION_TABLE(16)
 	RO_DATA(4)
 	ROMEND = .;
 #if defined(CONFIG_ROMKERNEL)
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 21/29] ia64: Move EXCEPTION_TABLE to RO_DATA segment
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (19 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 20/29] h8300: " Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 22/29] microblaze: " Kees Cook
                   ` (8 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The EXCEPTION_TABLE is read-only, so collapse it into RO_DATA.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/ia64/kernel/vmlinux.lds.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index 0d86fc8e88d5..18a732597112 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -6,6 +6,7 @@
 #include <asm/thread_info.h>
 
 #define EMITS_PT_NOTE
+#define RO_DATA_EXCEPTION_TABLE_ALIGN	16
 
 #include <asm-generic/vmlinux.lds.h>
 
@@ -70,7 +71,6 @@ SECTIONS {
 	/*
 	 * Read-only data
 	 */
-	EXCEPTION_TABLE(16)
 
 	/* MCA table */
 	. = ALIGN(16);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 22/29] microblaze: Move EXCEPTION_TABLE to RO_DATA segment
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (20 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 21/29] ia64: " Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 23/29] parisc: " Kees Cook
                   ` (7 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The EXCEPTION_TABLE is read-only, so collapse it into RO_DATA.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/microblaze/kernel/vmlinux.lds.S | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/microblaze/kernel/vmlinux.lds.S b/arch/microblaze/kernel/vmlinux.lds.S
index b8efb08204a1..abe5ff0f3773 100644
--- a/arch/microblaze/kernel/vmlinux.lds.S
+++ b/arch/microblaze/kernel/vmlinux.lds.S
@@ -11,6 +11,8 @@
 OUTPUT_ARCH(microblaze)
 ENTRY(microblaze_start)
 
+#define RO_DATA_EXCEPTION_TABLE_ALIGN	16
+
 #include <asm/page.h>
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/thread_info.h>
@@ -52,7 +54,6 @@ SECTIONS {
 
 	. = ALIGN(16);
 	RO_DATA(4096)
-	EXCEPTION_TABLE(16)
 
 	/*
 	 * sdata2 section can go anywhere, but must be word aligned
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 23/29] parisc: Move EXCEPTION_TABLE to RO_DATA segment
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (21 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 22/29] microblaze: " Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 24/29] powerpc: " Kees Cook
                   ` (6 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The EXCEPTION_TABLE is read-only, so collapse it into RO_DATA.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/parisc/kernel/vmlinux.lds.S | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S
index 12b3d7d5e9e4..1dc2f71e62b1 100644
--- a/arch/parisc/kernel/vmlinux.lds.S
+++ b/arch/parisc/kernel/vmlinux.lds.S
@@ -19,6 +19,7 @@
 				*(.data..vm0.pte)
 
 #define CC_USING_PATCHABLE_FUNCTION_ENTRY
+#define RO_DATA_EXCEPTION_TABLE_ALIGN	8
 
 #include <asm-generic/vmlinux.lds.h>
 
@@ -129,9 +130,6 @@ SECTIONS
 
 	RO_DATA(8)
 
-	/* RO because of BUILDTIME_EXTABLE_SORT */
-	EXCEPTION_TABLE(8)
-
 	/* unwind info */
 	.PARISC.unwind : {
 		__start___unwind = .;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 24/29] powerpc: Move EXCEPTION_TABLE to RO_DATA segment
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (22 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 23/29] parisc: " Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 25/29] xtensa: " Kees Cook
                   ` (5 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The EXCEPTION_TABLE is read-only, so collapse it into RO_DATA.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/powerpc/kernel/vmlinux.lds.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 4e7cec088c8b..2ed44e5824d5 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -7,6 +7,7 @@
 
 #define BSS_FIRST_SECTIONS *(.bss.prominit)
 #define EMITS_PT_NOTE
+#define RO_DATA_EXCEPTION_TABLE_ALIGN	0
 
 #include <asm/page.h>
 #include <asm-generic/vmlinux.lds.h>
@@ -162,7 +163,6 @@ SECTIONS
 		__stop__btb_flush_fixup = .;
 	}
 #endif
-	EXCEPTION_TABLE(0)
 
 /*
  * Init sections discarded at runtime
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 25/29] xtensa: Move EXCEPTION_TABLE to RO_DATA segment
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (23 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 24/29] powerpc: " Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:55 ` [PATCH 26/29] x86/mm: Remove redundant &s on addresses Kees Cook
                   ` (4 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The EXCEPTION_TABLE is read-only, so collapse it into RO_DATA.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/xtensa/kernel/vmlinux.lds.S | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S
index bdbd7c4056c1..7341964722ae 100644
--- a/arch/xtensa/kernel/vmlinux.lds.S
+++ b/arch/xtensa/kernel/vmlinux.lds.S
@@ -14,6 +14,8 @@
  * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
  */
 
+#define RO_DATA_EXCEPTION_TABLE_ALIGN	16
+
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/page.h>
 #include <asm/thread_info.h>
@@ -130,7 +132,6 @@ SECTIONS
 
   .fixup   : { *(.fixup) }
 
-  EXCEPTION_TABLE(16)
   /* Data section */
 
   _sdata = .;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 26/29] x86/mm: Remove redundant &s on addresses
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (24 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 25/29] xtensa: " Kees Cook
@ 2019-09-26 17:55 ` Kees Cook
  2019-09-26 17:56 ` [PATCH 27/29] x86/mm: Report which part of kernel image is freed Kees Cook
                   ` (3 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:55 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The &s on addresses are redundant and are better removed to match all
the other similar functions.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/mm/init_64.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 26299e9ce6da..e67ddca8b7a8 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1300,9 +1300,9 @@ void mark_rodata_ro(void)
 {
 	unsigned long start = PFN_ALIGN(_text);
 	unsigned long rodata_start = PFN_ALIGN(__start_rodata);
-	unsigned long end = (unsigned long) &__end_rodata_hpage_align;
-	unsigned long text_end = PFN_ALIGN(&_etext);
-	unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
+	unsigned long end = (unsigned long)__end_rodata_hpage_align;
+	unsigned long text_end = PFN_ALIGN(_etext);
+	unsigned long rodata_end = PFN_ALIGN(__end_rodata);
 	unsigned long all_end;
 
 	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 27/29] x86/mm: Report which part of kernel image is freed
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (25 preceding siblings ...)
  2019-09-26 17:55 ` [PATCH 26/29] x86/mm: Remove redundant &s on addresses Kees Cook
@ 2019-09-26 17:56 ` Kees Cook
  2019-09-26 17:56 ` [PATCH 28/29] x86/mm: Report actual image regions in /proc/iomem Kees Cook
                   ` (2 subsequent siblings)
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:56 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The memory freeing report wasn't very useful for figuring out which
parts of the kernel image were being freed. This adds the details for
clearer reporting.

Before:

[    2.150450] Freeing unused kernel image memory: 1348K
[    2.154574] Write protecting the kernel read-only data: 20480k
[    2.157641] Freeing unused kernel image memory: 2040K
[    2.158827] Freeing unused kernel image memory: 172K

After:

[    2.329678] Freeing unused kernel image (initmem) memory: 1348K
[    2.331953] Write protecting the kernel read-only data: 20480k
[    2.335361] Freeing unused kernel image (text/rodata gap) memory: 2040K
[    2.336927] Freeing unused kernel image (rodata/data gap) memory: 172K

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/include/asm/processor.h | 2 +-
 arch/x86/mm/init.c               | 8 ++++----
 arch/x86/mm/init_64.c            | 6 ++++--
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 6e0a3b43d027..790f250d39a8 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -958,7 +958,7 @@ static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
 
 extern unsigned long arch_align_stack(unsigned long sp);
 void free_init_pages(const char *what, unsigned long begin, unsigned long end);
-extern void free_kernel_image_pages(void *begin, void *end);
+extern void free_kernel_image_pages(const char *what, void *begin, void *end);
 
 void default_idle(void);
 #ifdef	CONFIG_XEN
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index fd10d91a6115..e7bb483557c9 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -829,14 +829,13 @@ void free_init_pages(const char *what, unsigned long begin, unsigned long end)
  * used for the kernel image only.  free_init_pages() will do the
  * right thing for either kind of address.
  */
-void free_kernel_image_pages(void *begin, void *end)
+void free_kernel_image_pages(const char *what, void *begin, void *end)
 {
 	unsigned long begin_ul = (unsigned long)begin;
 	unsigned long end_ul = (unsigned long)end;
 	unsigned long len_pages = (end_ul - begin_ul) >> PAGE_SHIFT;
 
-
-	free_init_pages("unused kernel image", begin_ul, end_ul);
+	free_init_pages(what, begin_ul, end_ul);
 
 	/*
 	 * PTI maps some of the kernel into userspace.  For performance,
@@ -865,7 +864,8 @@ void __ref free_initmem(void)
 
 	mem_encrypt_free_decrypted_mem();
 
-	free_kernel_image_pages(&__init_begin, &__init_end);
+	free_kernel_image_pages("unused kernel image (initmem)",
+				&__init_begin, &__init_end);
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index e67ddca8b7a8..dcb9bc961b39 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1334,8 +1334,10 @@ void mark_rodata_ro(void)
 	set_memory_ro(start, (end-start) >> PAGE_SHIFT);
 #endif
 
-	free_kernel_image_pages((void *)text_end, (void *)rodata_start);
-	free_kernel_image_pages((void *)rodata_end, (void *)_sdata);
+	free_kernel_image_pages("unused kernel image (text/rodata gap)",
+				(void *)text_end, (void *)rodata_start);
+	free_kernel_image_pages("unused kernel image (rodata/data gap)",
+				(void *)rodata_end, (void *)_sdata);
 
 	debug_checkwx();
 }
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 28/29] x86/mm: Report actual image regions in /proc/iomem
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (26 preceding siblings ...)
  2019-09-26 17:56 ` [PATCH 27/29] x86/mm: Report which part of kernel image is freed Kees Cook
@ 2019-09-26 17:56 ` Kees Cook
  2019-10-10 18:00   ` Borislav Petkov
  2019-09-26 17:56 ` [PATCH 29/29] x86: Use INT3 instead of NOP for linker fill bytes Kees Cook
  2019-10-10 18:03 ` [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Borislav Petkov
  29 siblings, 1 reply; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:56 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

The resource reservations in made for the kernel image did not reflect
the gaps between text, rodata, and data. This adds the rodata resource
and updates the start/end calculations to match the respective calls to
free_kernel_image_pages().

Before (booted with "nokaslr" for easier comparison):

00100000-bffd9fff : System RAM
  01000000-01e011d0 : Kernel code
  01e011d1-025619bf : Kernel data
  02a95000-035fffff : Kernel bss

After:

00100000-bffd9fff : System RAM
  01000000-01e011d0 : Kernel code
  02000000-023d4fff : Kernel rodata
  02400000-025619ff : Kernel data
  02a95000-035fffff : Kernel bss

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/kernel/setup.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index bbe35bf879f5..0bc71ee3a9c3 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -143,6 +143,13 @@ struct boot_params boot_params;
 /*
  * Machine setup..
  */
+static struct resource rodata_resource = {
+	.name	= "Kernel rodata",
+	.start	= 0,
+	.end	= 0,
+	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
+};
+
 static struct resource data_resource = {
 	.name	= "Kernel data",
 	.start	= 0,
@@ -951,7 +958,9 @@ void __init setup_arch(char **cmdline_p)
 
 	code_resource.start = __pa_symbol(_text);
 	code_resource.end = __pa_symbol(_etext)-1;
-	data_resource.start = __pa_symbol(_etext);
+	rodata_resource.start = __pa_symbol(__start_rodata);
+	rodata_resource.end = __pa_symbol(__end_rodata)-1;
+	data_resource.start = __pa_symbol(_sdata);
 	data_resource.end = __pa_symbol(_edata)-1;
 	bss_resource.start = __pa_symbol(__bss_start);
 	bss_resource.end = __pa_symbol(__bss_stop)-1;
@@ -1040,6 +1049,7 @@ void __init setup_arch(char **cmdline_p)
 
 	/* after parse_early_param, so could debug it */
 	insert_resource(&iomem_resource, &code_resource);
+	insert_resource(&iomem_resource, &rodata_resource);
 	insert_resource(&iomem_resource, &data_resource);
 	insert_resource(&iomem_resource, &bss_resource);
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* [PATCH 29/29] x86: Use INT3 instead of NOP for linker fill bytes
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (27 preceding siblings ...)
  2019-09-26 17:56 ` [PATCH 28/29] x86/mm: Report actual image regions in /proc/iomem Kees Cook
@ 2019-09-26 17:56 ` Kees Cook
  2019-10-10 18:03 ` [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Borislav Petkov
  29 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-09-26 17:56 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Kees Cook, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

Instead of using 0x90 (NOP) to fill bytes between functions, which makes
it easier to sloppily target functions in function pointer overwrite
attacks, fill with 0xCC (INT3) to force a trap. Also drops the space
between "=" and the value to better match the binutils documentation
https://sourceware.org/binutils/docs/ld/Output-Section-Fill.html#Output-Section-Fill

Example "objdump -d" before:

...
ffffffff810001e0 <start_cpu0>:
ffffffff810001e0:       48 8b 25 e1 b1 51 01    mov 0x151b1e1(%rip),%rsp        # ffffffff8251b3c8 <initial_stack>
ffffffff810001e7:       e9 d5 fe ff ff          jmpq   ffffffff810000c1 <secondary_startup_64+0x91>
ffffffff810001ec:       90                      nop
ffffffff810001ed:       90                      nop
ffffffff810001ee:       90                      nop
ffffffff810001ef:       90                      nop

ffffffff810001f0 <__startup_64>:
...

After:

...
ffffffff810001e0 <start_cpu0>:
ffffffff810001e0:       48 8b 25 41 79 53 01    mov 0x1537941(%rip),%rsp        # ffffffff82537b28 <initial_stack>
ffffffff810001e7:       e9 d5 fe ff ff          jmpq   ffffffff810000c1 <secondary_startup_64+0x91>
ffffffff810001ec:       cc                      int3
ffffffff810001ed:       cc                      int3
ffffffff810001ee:       cc                      int3
ffffffff810001ef:       cc                      int3

ffffffff810001f0 <__startup_64>:
...

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/kernel/vmlinux.lds.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index a5c8571e4967..a37817fafb22 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -144,7 +144,7 @@ SECTIONS
 		*(.text.__x86.indirect_thunk)
 		__indirect_thunk_end = .;
 #endif
-	} :text = 0x9090
+	} :text =0xcccc
 
 	/* End of text section, which should occupy whole number of pages */
 	_etext = .;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 42+ messages in thread

* Re: [PATCH 18/29] arm64: Move EXCEPTION_TABLE to RO_DATA segment
  2019-09-26 17:55 ` [PATCH 18/29] arm64: " Kees Cook
@ 2019-10-01  9:03   ` Will Deacon
  2019-10-01 15:48     ` Kees Cook
  0 siblings, 1 reply; 42+ messages in thread
From: Will Deacon @ 2019-10-01  9:03 UTC (permalink / raw)
  To: Kees Cook
  Cc: Thomas Gleixner, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

Hi Kees,

On Thu, Sep 26, 2019 at 10:55:51AM -0700, Kees Cook wrote:
> The EXCEPTION_TABLE is read-only, so collapse it into RO_DATA.
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  arch/arm64/kernel/vmlinux.lds.S | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
> index 81d94e371c95..c6ba2eee0ee8 100644
> --- a/arch/arm64/kernel/vmlinux.lds.S
> +++ b/arch/arm64/kernel/vmlinux.lds.S
> @@ -5,6 +5,8 @@
>   * Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
>   */
>  
> +#define RO_DATA_EXCEPTION_TABLE_ALIGN	8
> +
>  #include <asm-generic/vmlinux.lds.h>
>  #include <asm/cache.h>
>  #include <asm/kernel-pgtable.h>
> @@ -135,8 +137,8 @@ SECTIONS
>  	. = ALIGN(SEGMENT_ALIGN);
>  	_etext = .;			/* End of text section */
>  
> -	RO_DATA(PAGE_SIZE)		/* everything from this point to     */
> -	EXCEPTION_TABLE(8)		/* __init_begin will be marked RO NX */
> +	/* everything from this point to __init_begin will be marked RO NX */
> +	RO_DATA(PAGE_SIZE)
>  
>  	. = ALIGN(PAGE_SIZE);

Do you reckon it would be worth merging this last ALIGN directive into the
RO_DATA definition too? Given that we want to map the thing read-only, it
really has to be aligned either side.

Anyway, that's only a nit, so:

Acked-by: Will Deacon <will@kernel.org>

Will

P.S. Please CC the arm64 maintainers on arm64 patches -- I nearly missed
this one!

^ permalink raw reply	[flat|nested] 42+ messages in thread

* Re: [PATCH 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA
  2019-09-26 17:55 ` [PATCH 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA Kees Cook
@ 2019-10-01  9:05   ` Will Deacon
  2019-10-10 15:25   ` Borislav Petkov
  1 sibling, 0 replies; 42+ messages in thread
From: Will Deacon @ 2019-10-01  9:05 UTC (permalink / raw)
  To: Kees Cook
  Cc: Thomas Gleixner, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

On Thu, Sep 26, 2019 at 10:55:47AM -0700, Kees Cook wrote:
> Many architectures have an EXCEPTION_TABLE that needs only to be
> read-only. As such, it should live in RO_DATA. This creates a macro to
> identify this case for the architectures that can move EXCEPTION_TABLE
> into RO_DATA.
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  include/asm-generic/vmlinux.lds.h | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
> index d57a28786bb8..35a6cba39d9f 100644
> --- a/include/asm-generic/vmlinux.lds.h
> +++ b/include/asm-generic/vmlinux.lds.h
> @@ -69,6 +69,17 @@
>  #define NOTES_HEADERS_RESTORE
>  #endif
>  
> +/*
> + * Some architectures have non-executable read-only exception tables.
> + * They can be added to the RO_DATA segment by specifying their desired
> + * alignment.
> + */
> +#ifdef RO_DATA_EXCEPTION_TABLE_ALIGN
> +#define RO_DATA_EXCEPTION_TABLE	EXCEPTION_TABLE(RO_DATA_EXCEPTION_TABLE_ALIGN)
> +#else
> +#define RO_DATA_EXCEPTION_TABLE
> +#endif
> +
>  /* Align . to a 8 byte boundary equals to maximum function alignment. */
>  #define ALIGN_FUNCTION()  . = ALIGN(8)
>  
> @@ -508,6 +519,7 @@
>  		__stop___modver = .;					\
>  	}								\
>  									\
> +	RO_DATA_EXCEPTION_TABLE						\
>  	NOTES								\
>  									\
>  	. = ALIGN((align));						\

I had to read this one to understand the later arm64 change. It looks
fine to me, so:

Acked-by: Will Deacon <will@kernel.org>

Will

^ permalink raw reply	[flat|nested] 42+ messages in thread

* Re: [PATCH 18/29] arm64: Move EXCEPTION_TABLE to RO_DATA segment
  2019-10-01  9:03   ` Will Deacon
@ 2019-10-01 15:48     ` Kees Cook
  0 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-10-01 15:48 UTC (permalink / raw)
  To: Will Deacon
  Cc: Thomas Gleixner, Rick Edgecombe, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Arnd Bergmann,
	linux-arch, linuxppc-dev, linux-alpha, linux-ia64, linux-s390,
	linux-c6x-dev, Yoshinori Sato, Michal Simek, linux-parisc,
	linux-xtensa, x86, linux-kernel

On Tue, Oct 01, 2019 at 10:03:56AM +0100, Will Deacon wrote:
> Hi Kees,
> 
> On Thu, Sep 26, 2019 at 10:55:51AM -0700, Kees Cook wrote:
> > The EXCEPTION_TABLE is read-only, so collapse it into RO_DATA.
> > 
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > ---
> >  arch/arm64/kernel/vmlinux.lds.S | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
> > index 81d94e371c95..c6ba2eee0ee8 100644
> > --- a/arch/arm64/kernel/vmlinux.lds.S
> > +++ b/arch/arm64/kernel/vmlinux.lds.S
> > @@ -5,6 +5,8 @@
> >   * Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
> >   */
> >  
> > +#define RO_DATA_EXCEPTION_TABLE_ALIGN	8
> > +
> >  #include <asm-generic/vmlinux.lds.h>
> >  #include <asm/cache.h>
> >  #include <asm/kernel-pgtable.h>
> > @@ -135,8 +137,8 @@ SECTIONS
> >  	. = ALIGN(SEGMENT_ALIGN);
> >  	_etext = .;			/* End of text section */
> >  
> > -	RO_DATA(PAGE_SIZE)		/* everything from this point to     */
> > -	EXCEPTION_TABLE(8)		/* __init_begin will be marked RO NX */
> > +	/* everything from this point to __init_begin will be marked RO NX */
> > +	RO_DATA(PAGE_SIZE)
> >  
> >  	. = ALIGN(PAGE_SIZE);
> 
> Do you reckon it would be worth merging this last ALIGN directive into the
> RO_DATA definition too? Given that we want to map the thing read-only, it
> really has to be aligned either side.

Actually, taking a closer look, this appears to be redundant: RO_DATA()
ends with:

	. = ALIGN(align)

(where "align" is the "PAGE_SIZE" argument to RO_DATA())

> Anyway, that's only a nit, so:
> 
> Acked-by: Will Deacon <will@kernel.org>

Thanks!

> P.S. Please CC the arm64 maintainers on arm64 patches -- I nearly missed
> this one!

Okay, I can re-expand my list. I originally had done this but it was
getting to be a rather large set of people. :)

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 42+ messages in thread

* Re: [PATCH 07/29] x86: Restore "text" Program Header with dummy section
  2019-09-26 17:55 ` [PATCH 07/29] x86: Restore "text" Program Header with dummy section Kees Cook
@ 2019-10-10 10:33   ` Borislav Petkov
  2019-10-10 16:46     ` Kees Cook
  0 siblings, 1 reply; 42+ messages in thread
From: Borislav Petkov @ 2019-10-10 10:33 UTC (permalink / raw)
  To: Kees Cook
  Cc: Thomas Gleixner, Rick Edgecombe, Ingo Molnar, H. Peter Anvin,
	Dave Hansen, Andy Lutomirski, Arnd Bergmann, linux-arch,
	linuxppc-dev, linux-alpha, linux-ia64, linux-s390, linux-c6x-dev,
	Yoshinori Sato, Michal Simek, linux-parisc, linux-xtensa, x86,
	linux-kernel

On Thu, Sep 26, 2019 at 10:55:40AM -0700, Kees Cook wrote:
> Instead of depending on markings in the section following NOTES to
> restore the associated Program Header, use a dummy section, as done
> in other architectures.

This is very laconic and after some staring at ld.info, I think you mean
this:

"   If you place a section in one or more segments using ':PHDR', then
the linker will place all subsequent allocatable sections which do not
specify ':PHDR' in the same segments."

but I could be way off. Yes, no?

IOW, please write in the commit messages first what the problem is
you're addressing.

> This is preparation for moving NOTES into the
> RO_DATA macro.
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  arch/x86/kernel/vmlinux.lds.S | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
> index e2feacf921a0..788e78978030 100644
> --- a/arch/x86/kernel/vmlinux.lds.S
> +++ b/arch/x86/kernel/vmlinux.lds.S
> @@ -147,8 +147,9 @@ SECTIONS
>  	} :text = 0x9090
>  
>  	NOTES :text :note
> +	.dummy : { *(.dummy) } :text
>  
> -	EXCEPTION_TABLE(16) :text = 0x9090
> +	EXCEPTION_TABLE(16)

This is killing the filler byte but I have a suspicion that'll change
eventually to INT3... :)

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 42+ messages in thread

* Re: [PATCH 08/29] vmlinux.lds.h: Provide EMIT_PT_NOTE to indicate export of .notes
  2019-09-26 17:55 ` [PATCH 08/29] vmlinux.lds.h: Provide EMIT_PT_NOTE to indicate export of .notes Kees Cook
@ 2019-10-10 10:40   ` Borislav Petkov
  0 siblings, 0 replies; 42+ messages in thread
From: Borislav Petkov @ 2019-10-10 10:40 UTC (permalink / raw)
  To: Kees Cook
  Cc: Thomas Gleixner, Rick Edgecombe, Ingo Molnar, H. Peter Anvin,
	Dave Hansen, Andy Lutomirski, Arnd Bergmann, linux-arch,
	linuxppc-dev, linux-alpha, linux-ia64, linux-s390, linux-c6x-dev,
	Yoshinori Sato, Michal Simek, linux-parisc, linux-xtensa, x86,
	linux-kernel

On Thu, Sep 26, 2019 at 10:55:41AM -0700, Kees Cook wrote:
> In preparation for moving NOTES into RO_DATA, this provides a mechanism

s/this provides/provide/ - imperative tone. Check all your commit
messages pls.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 42+ messages in thread

* Re: [PATCH 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA
  2019-09-26 17:55 ` [PATCH 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA Kees Cook
  2019-10-01  9:05   ` Will Deacon
@ 2019-10-10 15:25   ` Borislav Petkov
  2019-10-10 16:47     ` Kees Cook
  1 sibling, 1 reply; 42+ messages in thread
From: Borislav Petkov @ 2019-10-10 15:25 UTC (permalink / raw)
  To: Kees Cook
  Cc: Thomas Gleixner, Rick Edgecombe, Ingo Molnar, H. Peter Anvin,
	Dave Hansen, Andy Lutomirski, Arnd Bergmann, linux-arch,
	linuxppc-dev, linux-alpha, linux-ia64, linux-s390, linux-c6x-dev,
	Yoshinori Sato, Michal Simek, linux-parisc, linux-xtensa, x86,
	linux-kernel

On Thu, Sep 26, 2019 at 10:55:47AM -0700, Kees Cook wrote:
> Many architectures have an EXCEPTION_TABLE that needs only to be
> read-only. As such, it should live in RO_DATA. This creates a macro to
> identify this case for the architectures that can move EXCEPTION_TABLE
> into RO_DATA.
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  include/asm-generic/vmlinux.lds.h | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
> index d57a28786bb8..35a6cba39d9f 100644
> --- a/include/asm-generic/vmlinux.lds.h
> +++ b/include/asm-generic/vmlinux.lds.h
> @@ -69,6 +69,17 @@
>  #define NOTES_HEADERS_RESTORE
>  #endif
>  
> +/*
> + * Some architectures have non-executable read-only exception tables.
> + * They can be added to the RO_DATA segment by specifying their desired
> + * alignment.
> + */
> +#ifdef RO_DATA_EXCEPTION_TABLE_ALIGN
> +#define RO_DATA_EXCEPTION_TABLE	EXCEPTION_TABLE(RO_DATA_EXCEPTION_TABLE_ALIGN)
> +#else
> +#define RO_DATA_EXCEPTION_TABLE
> +#endif
> +
>  /* Align . to a 8 byte boundary equals to maximum function alignment. */
>  #define ALIGN_FUNCTION()  . = ALIGN(8)
>  
> @@ -508,6 +519,7 @@
>  		__stop___modver = .;					\
>  	}								\
>  									\
> +	RO_DATA_EXCEPTION_TABLE						\
>  	NOTES								\
>  									\
>  	. = ALIGN((align));						\
> -- 

I think you can drop the "DATA" from the names as it is kinda clear
where the exception table lands:

RO_EXCEPTION_TABLE_ALIGN
RO_EXCEPTION_TABLE

The "read-only" part is the important one.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 42+ messages in thread

* Re: [PATCH 07/29] x86: Restore "text" Program Header with dummy section
  2019-10-10 10:33   ` Borislav Petkov
@ 2019-10-10 16:46     ` Kees Cook
  0 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-10-10 16:46 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: Thomas Gleixner, Rick Edgecombe, Ingo Molnar, H. Peter Anvin,
	Dave Hansen, Andy Lutomirski, Arnd Bergmann, linux-arch,
	linuxppc-dev, linux-alpha, linux-ia64, linux-s390, linux-c6x-dev,
	Yoshinori Sato, Michal Simek, linux-parisc, linux-xtensa, x86,
	linux-kernel

On Thu, Oct 10, 2019 at 12:33:05PM +0200, Borislav Petkov wrote:
> On Thu, Sep 26, 2019 at 10:55:40AM -0700, Kees Cook wrote:
> > Instead of depending on markings in the section following NOTES to
> > restore the associated Program Header, use a dummy section, as done
> > in other architectures.
> 
> This is very laconic and after some staring at ld.info, I think you mean
> this:
> 
> "   If you place a section in one or more segments using ':PHDR', then
> the linker will place all subsequent allocatable sections which do not
> specify ':PHDR' in the same segments."
> 
> but I could be way off. Yes, no?
> 
> IOW, please write in the commit messages first what the problem is
> you're addressing.

Yeah, that's much improved. I really struggled to describe this, given
how weird the linker script logic is here.

> > --- a/arch/x86/kernel/vmlinux.lds.S
> > +++ b/arch/x86/kernel/vmlinux.lds.S
> > @@ -147,8 +147,9 @@ SECTIONS
> >  	} :text = 0x9090
> >  
> >  	NOTES :text :note
> > +	.dummy : { *(.dummy) } :text
> >  
> > -	EXCEPTION_TABLE(16) :text = 0x9090
> > +	EXCEPTION_TABLE(16)
> 
> This is killing the filler byte but I have a suspicion that'll change
> eventually to INT3... :)

Yes, though since the exception table isn't executable, filling with
0x90 has no meaning, and I think when I looked at the alignment there
were actually no fill bytes from here on. But it doesn't matter; it all
goes away in the end.

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 42+ messages in thread

* Re: [PATCH 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA
  2019-10-10 15:25   ` Borislav Petkov
@ 2019-10-10 16:47     ` Kees Cook
  0 siblings, 0 replies; 42+ messages in thread
From: Kees Cook @ 2019-10-10 16:47 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: Thomas Gleixner, Rick Edgecombe, Ingo Molnar, H. Peter Anvin,
	Dave Hansen, Andy Lutomirski, Arnd Bergmann, linux-arch,
	linuxppc-dev, linux-alpha, linux-ia64, linux-s390, linux-c6x-dev,
	Yoshinori Sato, Michal Simek, linux-parisc, linux-xtensa, x86,
	linux-kernel

On Thu, Oct 10, 2019 at 05:25:16PM +0200, Borislav Petkov wrote:
> On Thu, Sep 26, 2019 at 10:55:47AM -0700, Kees Cook wrote:
> > Many architectures have an EXCEPTION_TABLE that needs only to be
> > read-only. As such, it should live in RO_DATA. This creates a macro to
> > identify this case for the architectures that can move EXCEPTION_TABLE
> > into RO_DATA.
> > 
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > ---
> >  include/asm-generic/vmlinux.lds.h | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> > 
> > diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
> > index d57a28786bb8..35a6cba39d9f 100644
> > --- a/include/asm-generic/vmlinux.lds.h
> > +++ b/include/asm-generic/vmlinux.lds.h
> > @@ -69,6 +69,17 @@
> >  #define NOTES_HEADERS_RESTORE
> >  #endif
> >  
> > +/*
> > + * Some architectures have non-executable read-only exception tables.
> > + * They can be added to the RO_DATA segment by specifying their desired
> > + * alignment.
> > + */
> > +#ifdef RO_DATA_EXCEPTION_TABLE_ALIGN
> > +#define RO_DATA_EXCEPTION_TABLE	EXCEPTION_TABLE(RO_DATA_EXCEPTION_TABLE_ALIGN)
> > +#else
> > +#define RO_DATA_EXCEPTION_TABLE
> > +#endif
> > +
> >  /* Align . to a 8 byte boundary equals to maximum function alignment. */
> >  #define ALIGN_FUNCTION()  . = ALIGN(8)
> >  
> > @@ -508,6 +519,7 @@
> >  		__stop___modver = .;					\
> >  	}								\
> >  									\
> > +	RO_DATA_EXCEPTION_TABLE						\
> >  	NOTES								\
> >  									\
> >  	. = ALIGN((align));						\
> > -- 
> 
> I think you can drop the "DATA" from the names as it is kinda clear
> where the exception table lands:
> 
> RO_EXCEPTION_TABLE_ALIGN
> RO_EXCEPTION_TABLE
> 
> The "read-only" part is the important one.

Excellent point; I was not loving the how long the name was either. :)

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 42+ messages in thread

* Re: [PATCH 28/29] x86/mm: Report actual image regions in /proc/iomem
  2019-09-26 17:56 ` [PATCH 28/29] x86/mm: Report actual image regions in /proc/iomem Kees Cook
@ 2019-10-10 18:00   ` Borislav Petkov
  0 siblings, 0 replies; 42+ messages in thread
From: Borislav Petkov @ 2019-10-10 18:00 UTC (permalink / raw)
  To: Kees Cook
  Cc: Thomas Gleixner, Rick Edgecombe, Ingo Molnar, H. Peter Anvin,
	Dave Hansen, Andy Lutomirski, Arnd Bergmann, linux-arch,
	linuxppc-dev, linux-alpha, linux-ia64, linux-s390, linux-c6x-dev,
	Yoshinori Sato, Michal Simek, linux-parisc, linux-xtensa, x86,
	linux-kernel

On Thu, Sep 26, 2019 at 10:56:01AM -0700, Kees Cook wrote:
> The resource reservations in made for the kernel image did not reflect
			      ^
			      /proc/iomem

> the gaps between text, rodata, and data. This adds the rodata resource

s/This adds/Add/

> and updates the start/end calculations to match the respective calls to

s/updates/update/

> free_kernel_image_pages().
> 
> Before (booted with "nokaslr" for easier comparison):

...

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 42+ messages in thread

* Re: [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES
  2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
                   ` (28 preceding siblings ...)
  2019-09-26 17:56 ` [PATCH 29/29] x86: Use INT3 instead of NOP for linker fill bytes Kees Cook
@ 2019-10-10 18:03 ` Borislav Petkov
  2019-10-10 23:57   ` Kees Cook
  29 siblings, 1 reply; 42+ messages in thread
From: Borislav Petkov @ 2019-10-10 18:03 UTC (permalink / raw)
  To: Kees Cook
  Cc: Thomas Gleixner, Rick Edgecombe, Ingo Molnar, H. Peter Anvin,
	Dave Hansen, Andy Lutomirski, Arnd Bergmann, linux-arch,
	linuxppc-dev, linux-alpha, linux-ia64, linux-s390, linux-c6x-dev,
	Yoshinori Sato, Michal Simek, linux-parisc, linux-xtensa, x86,
	linux-kernel

On Thu, Sep 26, 2019 at 10:55:33AM -0700, Kees Cook wrote:
> This series works to move the linker sections for NOTES and
> EXCEPTION_TABLE into the RO_DATA area, where they belong on most
> (all?) architectures. The problem being addressed was the discovery
> by Rick Edgecombe that the exception table was accidentally marked
> executable while he was developing his execute-only-memory series. When
> permissions were flipped from readable-and-executable to only-executable,
> the exception table became unreadable, causing things to explode rather
> badly. :)
> 
> Roughly speaking, the steps are:
> 
> - regularize the linker names for PT_NOTE and PT_LOAD program headers
>   (to "note" and "text" respectively)
> - regularize restoration of linker section to program header assignment
>   (when PT_NOTE exists)
> - move NOTES into RO_DATA
> - finish macro naming conversions for RO_DATA and RW_DATA
> - move EXCEPTION_TABLE into RO_DATA on architectures where this is clear
> - clean up some x86-specific reporting of kernel memory resources
> - switch x86 linker fill byte from x90 (NOP) to 0xcc (INT3), just because
>   I finally realized what that trailing ": 0x9090" meant -- and we should
>   trap, not slide, if execution lands in section padding

Yap, nice patchset overall.

> Since these changes are treewide, I'd love to get architecture-maintainer
> Acks and either have this live in x86 -tip or in my own tree, however
> people think it should go.

Sure, I don't mind taking v2 through tip once I get ACKs from the
respective arch maintainers.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 42+ messages in thread

* Re: [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES
  2019-10-10 18:03 ` [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Borislav Petkov
@ 2019-10-10 23:57   ` Kees Cook
  2019-10-11  1:38     ` hpa
  0 siblings, 1 reply; 42+ messages in thread
From: Kees Cook @ 2019-10-10 23:57 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: Thomas Gleixner, Rick Edgecombe, Ingo Molnar, H. Peter Anvin,
	Dave Hansen, Andy Lutomirski, Arnd Bergmann, linux-arch,
	linuxppc-dev, linux-alpha, linux-ia64, linux-s390, linux-c6x-dev,
	Yoshinori Sato, Michal Simek, linux-parisc, linux-xtensa, x86,
	linux-kernel

On Thu, Oct 10, 2019 at 08:03:31PM +0200, Borislav Petkov wrote:
> On Thu, Sep 26, 2019 at 10:55:33AM -0700, Kees Cook wrote:
> > This series works to move the linker sections for NOTES and
> > EXCEPTION_TABLE into the RO_DATA area, where they belong on most
> > (all?) architectures. The problem being addressed was the discovery
> > by Rick Edgecombe that the exception table was accidentally marked
> > executable while he was developing his execute-only-memory series. When
> > permissions were flipped from readable-and-executable to only-executable,
> > the exception table became unreadable, causing things to explode rather
> > badly. :)
> > 
> > Roughly speaking, the steps are:
> > 
> > - regularize the linker names for PT_NOTE and PT_LOAD program headers
> >   (to "note" and "text" respectively)
> > - regularize restoration of linker section to program header assignment
> >   (when PT_NOTE exists)
> > - move NOTES into RO_DATA
> > - finish macro naming conversions for RO_DATA and RW_DATA
> > - move EXCEPTION_TABLE into RO_DATA on architectures where this is clear
> > - clean up some x86-specific reporting of kernel memory resources
> > - switch x86 linker fill byte from x90 (NOP) to 0xcc (INT3), just because
> >   I finally realized what that trailing ": 0x9090" meant -- and we should
> >   trap, not slide, if execution lands in section padding
> 
> Yap, nice patchset overall.

Thanks!

> > Since these changes are treewide, I'd love to get architecture-maintainer
> > Acks and either have this live in x86 -tip or in my own tree, however
> > people think it should go.
> 
> Sure, I don't mind taking v2 through tip once I get ACKs from the
> respective arch maintainers.

Okay, excellent. I've only had acks from arm64, but I'll call it out
again in v2. Thanks for the review!

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 42+ messages in thread

* Re: [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES
  2019-10-10 23:57   ` Kees Cook
@ 2019-10-11  1:38     ` hpa
  0 siblings, 0 replies; 42+ messages in thread
From: hpa @ 2019-10-11  1:38 UTC (permalink / raw)
  To: Kees Cook, Borislav Petkov
  Cc: Thomas Gleixner, Rick Edgecombe, Ingo Molnar, Dave Hansen,
	Andy Lutomirski, Arnd Bergmann, linux-arch, linuxppc-dev,
	linux-alpha, linux-ia64, linux-s390, linux-c6x-dev,
	Yoshinori Sato, Michal Simek, linux-parisc, linux-xtensa, x86,
	linux-kernel

On October 10, 2019 4:57:36 PM PDT, Kees Cook <keescook@chromium.org> wrote:
>On Thu, Oct 10, 2019 at 08:03:31PM +0200, Borislav Petkov wrote:
>> On Thu, Sep 26, 2019 at 10:55:33AM -0700, Kees Cook wrote:
>> > This series works to move the linker sections for NOTES and
>> > EXCEPTION_TABLE into the RO_DATA area, where they belong on most
>> > (all?) architectures. The problem being addressed was the discovery
>> > by Rick Edgecombe that the exception table was accidentally marked
>> > executable while he was developing his execute-only-memory series.
>When
>> > permissions were flipped from readable-and-executable to
>only-executable,
>> > the exception table became unreadable, causing things to explode
>rather
>> > badly. :)
>> > 
>> > Roughly speaking, the steps are:
>> > 
>> > - regularize the linker names for PT_NOTE and PT_LOAD program
>headers
>> >   (to "note" and "text" respectively)
>> > - regularize restoration of linker section to program header
>assignment
>> >   (when PT_NOTE exists)
>> > - move NOTES into RO_DATA
>> > - finish macro naming conversions for RO_DATA and RW_DATA
>> > - move EXCEPTION_TABLE into RO_DATA on architectures where this is
>clear
>> > - clean up some x86-specific reporting of kernel memory resources
>> > - switch x86 linker fill byte from x90 (NOP) to 0xcc (INT3), just
>because
>> >   I finally realized what that trailing ": 0x9090" meant -- and we
>should
>> >   trap, not slide, if execution lands in section padding
>> 
>> Yap, nice patchset overall.
>
>Thanks!
>
>> > Since these changes are treewide, I'd love to get
>architecture-maintainer
>> > Acks and either have this live in x86 -tip or in my own tree,
>however
>> > people think it should go.
>> 
>> Sure, I don't mind taking v2 through tip once I get ACKs from the
>> respective arch maintainers.
>
>Okay, excellent. I've only had acks from arm64, but I'll call it out
>again in v2. Thanks for the review!

I would like to once again advocate for the generalized link table mechanism. It is nuts that each individual table should need vmlinux.lds hacking across architectures.
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

^ permalink raw reply	[flat|nested] 42+ messages in thread

end of thread, other threads:[~2019-10-11  1:39 UTC | newest]

Thread overview: 42+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-09-26 17:55 [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Kees Cook
2019-09-26 17:55 ` [PATCH 01/29] powerpc: Rename "notes" PT_NOTE to "note" Kees Cook
2019-09-26 17:55 ` [PATCH 02/29] powerpc: Remove PT_NOTE workaround Kees Cook
2019-09-26 17:55 ` [PATCH 03/29] powerpc: Rename PT_LOAD identifier "kernel" to "text" Kees Cook
2019-09-26 17:55 ` [PATCH 04/29] alpha: " Kees Cook
2019-09-26 17:55 ` [PATCH 05/29] ia64: Rename PT_LOAD identifier "code" " Kees Cook
2019-09-26 17:55 ` [PATCH 06/29] s390: Move RO_DATA into "text" PT_LOAD Program Header Kees Cook
2019-09-26 17:55 ` [PATCH 07/29] x86: Restore "text" Program Header with dummy section Kees Cook
2019-10-10 10:33   ` Borislav Petkov
2019-10-10 16:46     ` Kees Cook
2019-09-26 17:55 ` [PATCH 08/29] vmlinux.lds.h: Provide EMIT_PT_NOTE to indicate export of .notes Kees Cook
2019-10-10 10:40   ` Borislav Petkov
2019-09-26 17:55 ` [PATCH 09/29] vmlinux.lds.h: Move Program Header restoration into NOTES macro Kees Cook
2019-09-26 17:55 ` [PATCH 10/29] vmlinux.lds.h: Move NOTES into RO_DATA Kees Cook
2019-09-26 17:55 ` [PATCH 11/29] vmlinux.lds.h: Replace RODATA with RO_DATA Kees Cook
2019-09-26 17:55 ` [PATCH 12/29] vmlinux.lds.h: Replace RO_DATA_SECTION " Kees Cook
2019-09-26 17:55 ` [PATCH 13/29] vmlinux.lds.h: Replace RW_DATA_SECTION with RW_DATA Kees Cook
2019-09-26 17:55 ` [PATCH 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA Kees Cook
2019-10-01  9:05   ` Will Deacon
2019-10-10 15:25   ` Borislav Petkov
2019-10-10 16:47     ` Kees Cook
2019-09-26 17:55 ` [PATCH 15/29] x86: Actually use _etext for end of text segment Kees Cook
2019-09-26 17:55 ` [PATCH 16/29] x86: Move EXCEPTION_TABLE to RO_DATA segment Kees Cook
2019-09-26 17:55 ` [PATCH 17/29] alpha: " Kees Cook
2019-09-26 17:55 ` [PATCH 18/29] arm64: " Kees Cook
2019-10-01  9:03   ` Will Deacon
2019-10-01 15:48     ` Kees Cook
2019-09-26 17:55 ` [PATCH 19/29] c6x: " Kees Cook
2019-09-26 17:55 ` [PATCH 20/29] h8300: " Kees Cook
2019-09-26 17:55 ` [PATCH 21/29] ia64: " Kees Cook
2019-09-26 17:55 ` [PATCH 22/29] microblaze: " Kees Cook
2019-09-26 17:55 ` [PATCH 23/29] parisc: " Kees Cook
2019-09-26 17:55 ` [PATCH 24/29] powerpc: " Kees Cook
2019-09-26 17:55 ` [PATCH 25/29] xtensa: " Kees Cook
2019-09-26 17:55 ` [PATCH 26/29] x86/mm: Remove redundant &s on addresses Kees Cook
2019-09-26 17:56 ` [PATCH 27/29] x86/mm: Report which part of kernel image is freed Kees Cook
2019-09-26 17:56 ` [PATCH 28/29] x86/mm: Report actual image regions in /proc/iomem Kees Cook
2019-10-10 18:00   ` Borislav Petkov
2019-09-26 17:56 ` [PATCH 29/29] x86: Use INT3 instead of NOP for linker fill bytes Kees Cook
2019-10-10 18:03 ` [PATCH 00/29] vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES Borislav Petkov
2019-10-10 23:57   ` Kees Cook
2019-10-11  1:38     ` hpa

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