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From: Matt Redfearn <matt.redfearn@imgtec.com>
To: Ralf Baechle <ralf@linux-mips.org>
Cc: <linux-mips@linux-mips.org>,
	<kernel-hardening@lists.openwall.com>,
	"Matt Redfearn" <matt.redfearn@imgtec.com>,
	<linux-kernel@vger.kernel.org>
Subject: [PATCH v2 08/11] MIPS: Add CONFIG_RELOCATABLE Kconfig option
Date: Thu, 31 Mar 2016 10:05:39 +0100	[thread overview]
Message-ID: <1459415142-3412-9-git-send-email-matt.redfearn@imgtec.com> (raw)
In-Reply-To: <1459415142-3412-1-git-send-email-matt.redfearn@imgtec.com>

Add option to KConfig to enable the kernel to relocate itself at
runtime.

Relocation is supported R2 and later of the MIPS architecture, 32bit
and 64bit. The platform is also required to provide support through
plat_get_fdt() added in a later patch.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
---

Changes in v2: None

 arch/mips/Kconfig | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 6f55e1a5d645..4bf1814e57a5 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -473,6 +473,7 @@ config MIPS_MALTA
 	select SYS_SUPPORTS_MULTITHREADING
 	select SYS_SUPPORTS_SMARTMIPS
 	select SYS_SUPPORTS_ZBOOT
+	select SYS_SUPPORTS_RELOCATABLE
 	select USE_OF
 	select ZONE_DMA32 if 64BIT
 	select BUILTIN_DTB
@@ -516,6 +517,7 @@ config MIPS_SEAD3
 	select SYS_SUPPORTS_SMARTMIPS
 	select SYS_SUPPORTS_MICROMIPS
 	select SYS_SUPPORTS_MIPS16
+	select SYS_SUPPORTS_RELOCATABLE
 	select USB_EHCI_BIG_ENDIAN_DESC
 	select USB_EHCI_BIG_ENDIAN_MMIO
 	select USE_OF
@@ -1156,6 +1158,13 @@ config ISA_DMA_API
 config HOLES_IN_ZONE
 	bool
 
+config SYS_SUPPORTS_RELOCATABLE
+	bool
+	help
+	 Selected if the platform supports relocating the kernel.
+	 The platform must provide plat_get_fdt() if it selects CONFIG_USE_OF
+	 to allow access to command line and entropy sources.
+
 #
 # Endianness selection.  Sufficiently obscure so many users don't know what to
 # answer,so we try hard to limit the available choices.  Also the use of a
@@ -2478,6 +2487,15 @@ config NUMA
 config SYS_SUPPORTS_NUMA
 	bool
 
+config RELOCATABLE
+	bool "Relocatable kernel"
+	depends on SYS_SUPPORTS_RELOCATABLE && (CPU_MIPS32_R2 || CPU_MIPS64_R2 || CPU_MIPS32_R6 || CPU_MIPS64_R6)
+	help
+	  This builds a kernel image that retains relocation information
+	  so it can be loaded someplace besides the default 1MB.
+	  The relocations make the kernel binary about 15% larger,
+	  but are discarded at runtime
+
 config RELOCATION_TABLE_SIZE
 	hex "Relocation table size"
 	depends on RELOCATABLE
-- 
2.5.0

  parent reply	other threads:[~2016-03-31  9:32 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-31  9:05 [PATCH v2 00/11] MIPS relocatable kernel & KASLR Matt Redfearn
2016-03-31  9:05 ` [PATCH v2 01/11] MIPS: tools: Add relocs tool Matt Redfearn
2016-03-31  9:05 ` [PATCH v2 02/11] MIPS: tools: Build " Matt Redfearn
2016-03-31  9:05 ` [PATCH v2 03/11] MIPS: Reserve space for relocation table Matt Redfearn
2016-03-31  9:05 ` [PATCH v2 04/11] MIPS: Generate relocation table when CONFIG_RELOCATABLE Matt Redfearn
2016-03-31  9:05 ` [PATCH v2 05/11] MIPS: Kernel: Add relocate.c Matt Redfearn
2016-03-31  9:05 ` [PATCH v2 06/11] MIPS: Call relocate_kernel if CONFIG_RELOCATABLE=y Matt Redfearn
2016-03-31  9:05 ` [PATCH v2 07/11] MIPS: bootmem: When relocatable, free memory below kernel Matt Redfearn
2016-03-31  9:05 ` Matt Redfearn [this message]
2016-03-31  9:05 ` [PATCH v2 09/11] MIPS: Introduce plat_get_fdt a platform API to retrieve the FDT Matt Redfearn
2016-03-31  9:05 ` [PATCH v2 10/11] MIPS: Kernel: Implement KASLR using CONFIG_RELOCATABLE Matt Redfearn
2016-03-31  9:05 ` [PATCH v2 11/11] MIPS: KASLR: Print relocation Information on boot Matt Redfearn
2016-03-31 12:38   ` Sergei Shtylyov
2016-04-01  8:44     ` Ralf Baechle
2016-04-01  9:07       ` Matt Redfearn
2016-04-04 19:46 ` [kernel-hardening] [PATCH v2 00/11] MIPS relocatable kernel & KASLR Kees Cook
2016-04-04 23:37   ` Ralf Baechle
2016-04-04 23:56     ` Kees Cook
2016-04-05  9:09       ` James Hogan
2016-04-05 18:10         ` Kees Cook
2016-04-05 21:00           ` James Hogan
2016-04-05 12:14     ` Maciej W. Rozycki

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