From: Matt Redfearn <matt.redfearn@imgtec.com> To: <linux-mips@linux-mips.org> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Subject: [PATCH 3/9] MIPS: Reserve space for relocation table Date: Thu, 3 Dec 2015 10:08:11 +0000 [thread overview] Message-ID: <1449137297-30464-4-git-send-email-matt.redfearn@imgtec.com> (raw) In-Reply-To: <1449137297-30464-1-git-send-email-matt.redfearn@imgtec.com> When CONFIG_RELOCATABLE is enabled, add a new section in the memory map to be filled with relocation data. CONFIG_RELOCATION_TABLE_SIZE allows the amount of space reserved to be adjusted if necessary. The relocs tool will populate this reserved space with relocation information. The space is reserved within the elf by filling it with 0's, and an invalid entry is left at the start of the space such that kernel relocation will be aborted if the table is empty. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> --- arch/mips/Kconfig | 14 ++++++++++++++ arch/mips/kernel/vmlinux.lds.S | 20 ++++++++++++++++++++ 2 files changed, 34 insertions(+) diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index e3aa5b0b4ef1..b8ed64dfaafc 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -2431,6 +2431,20 @@ config NUMA config SYS_SUPPORTS_NUMA bool +config RELOCATION_TABLE_SIZE + hex "Relocation table size" + depends on RELOCATABLE + range 0x0 0x01000000 + default "0x00100000" + ---help--- + A table of relocation data will be appended to the kernel binary + and parsed at boot to fix up the relocated kernel. + + This option allows the amount of space reserved for the table to be + adjusted, although the default of 1Mb should be ok in most cases. + + If unsure, leave at the default value. + config NODES_SHIFT int default "6" diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S index 07d32a4aea60..27d70423f1dd 100644 --- a/arch/mips/kernel/vmlinux.lds.S +++ b/arch/mips/kernel/vmlinux.lds.S @@ -128,6 +128,26 @@ SECTIONS #ifdef CONFIG_SMP PERCPU_SECTION(1 << CONFIG_MIPS_L1_CACHE_SHIFT) #endif + +#ifdef CONFIG_RELOCATABLE + . = ALIGN(4); + + .data.reloc : { + _relocation_start = .; + /* Space for relocation table + * This needs to be filled so that the + * relocs tool can overwrite the content. + * An invalid value is left at the start of the + * section to abort relocation if the table + * has not been filled in. + */ + LONG(0xFFFFFFFF); + FILL(0); + . += CONFIG_RELOCATION_TABLE_SIZE - 4; + _relocation_end = .; + } +#endif + #ifdef CONFIG_MIPS_RAW_APPENDED_DTB __appended_dtb = .; /* leave space for appended DTB */ -- 2.1.4
WARNING: multiple messages have this Message-ID (diff)
From: Matt Redfearn <matt.redfearn@imgtec.com> To: linux-mips@linux-mips.org Cc: Matt Redfearn <matt.redfearn@imgtec.com> Subject: [PATCH 3/9] MIPS: Reserve space for relocation table Date: Thu, 3 Dec 2015 10:08:11 +0000 [thread overview] Message-ID: <1449137297-30464-4-git-send-email-matt.redfearn@imgtec.com> (raw) Message-ID: <20151203100811.AnV3OcOXnuDyMieX1MIwzTV2Zxibg1nQZ8cQkWNLqUc@z> (raw) In-Reply-To: <1449137297-30464-1-git-send-email-matt.redfearn@imgtec.com> When CONFIG_RELOCATABLE is enabled, add a new section in the memory map to be filled with relocation data. CONFIG_RELOCATION_TABLE_SIZE allows the amount of space reserved to be adjusted if necessary. The relocs tool will populate this reserved space with relocation information. The space is reserved within the elf by filling it with 0's, and an invalid entry is left at the start of the space such that kernel relocation will be aborted if the table is empty. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> --- arch/mips/Kconfig | 14 ++++++++++++++ arch/mips/kernel/vmlinux.lds.S | 20 ++++++++++++++++++++ 2 files changed, 34 insertions(+) diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index e3aa5b0b4ef1..b8ed64dfaafc 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -2431,6 +2431,20 @@ config NUMA config SYS_SUPPORTS_NUMA bool +config RELOCATION_TABLE_SIZE + hex "Relocation table size" + depends on RELOCATABLE + range 0x0 0x01000000 + default "0x00100000" + ---help--- + A table of relocation data will be appended to the kernel binary + and parsed at boot to fix up the relocated kernel. + + This option allows the amount of space reserved for the table to be + adjusted, although the default of 1Mb should be ok in most cases. + + If unsure, leave at the default value. + config NODES_SHIFT int default "6" diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S index 07d32a4aea60..27d70423f1dd 100644 --- a/arch/mips/kernel/vmlinux.lds.S +++ b/arch/mips/kernel/vmlinux.lds.S @@ -128,6 +128,26 @@ SECTIONS #ifdef CONFIG_SMP PERCPU_SECTION(1 << CONFIG_MIPS_L1_CACHE_SHIFT) #endif + +#ifdef CONFIG_RELOCATABLE + . = ALIGN(4); + + .data.reloc : { + _relocation_start = .; + /* Space for relocation table + * This needs to be filled so that the + * relocs tool can overwrite the content. + * An invalid value is left at the start of the + * section to abort relocation if the table + * has not been filled in. + */ + LONG(0xFFFFFFFF); + FILL(0); + . += CONFIG_RELOCATION_TABLE_SIZE - 4; + _relocation_end = .; + } +#endif + #ifdef CONFIG_MIPS_RAW_APPENDED_DTB __appended_dtb = .; /* leave space for appended DTB */ -- 2.1.4
next prev parent reply other threads:[~2015-12-03 10:09 UTC|newest] Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-12-03 10:08 [PATCH 0/9] MIPS Relocatable kernel & KASLR Matt Redfearn 2015-12-03 10:08 ` Matt Redfearn 2015-12-03 10:08 ` [PATCH 1/9] MIPS: tools: Add relocs tool Matt Redfearn 2015-12-03 10:08 ` Matt Redfearn 2015-12-03 10:08 ` [PATCH 2/9] MIPS: tools: Build " Matt Redfearn 2015-12-03 10:08 ` Matt Redfearn 2015-12-03 10:08 ` Matt Redfearn [this message] 2015-12-03 10:08 ` [PATCH 3/9] MIPS: Reserve space for relocation table Matt Redfearn 2015-12-03 10:08 ` [PATCH 4/9] MIPS: Generate relocation table when CONFIG_RELOCATABLE Matt Redfearn 2015-12-03 10:08 ` Matt Redfearn 2015-12-03 10:08 ` [PATCH 5/9] MIPS: Kernel: Add relocate.c Matt Redfearn 2015-12-03 10:08 ` Matt Redfearn 2015-12-03 10:08 ` [PATCH 6/9] MIPS: Call relocate_kernel if CONFIG_RELOCATABLE=y Matt Redfearn 2015-12-03 10:08 ` Matt Redfearn 2015-12-03 14:24 ` Sergei Shtylyov 2015-12-03 14:53 ` Matt Redfearn 2015-12-03 14:53 ` Matt Redfearn 2015-12-03 17:46 ` Sergei Shtylyov 2015-12-03 18:54 ` James Hogan 2015-12-04 8:20 ` Matt Redfearn 2015-12-04 8:20 ` Matt Redfearn 2015-12-04 15:37 ` Ralf Baechle 2015-12-04 15:45 ` Matt Redfearn 2015-12-04 15:45 ` Matt Redfearn 2015-12-03 10:08 ` [PATCH 7/9] MIPS: bootmem: When relocatable, free memory below kernel Matt Redfearn 2015-12-03 10:08 ` Matt Redfearn 2015-12-03 10:08 ` [PATCH 8/9] MIPS: Add CONFIG_RELOCATABLE Kconfig option Matt Redfearn 2015-12-03 10:08 ` Matt Redfearn 2015-12-03 10:08 ` [PATCH 9/9] MIPS: Kernel: Implement kASLR using CONFIG_RELOCATABLE Matt Redfearn 2015-12-03 10:08 ` Matt Redfearn 2015-12-03 22:23 ` [PATCH 0/9] MIPS Relocatable kernel & KASLR Joshua Kinard 2015-12-04 8:14 ` Matt Redfearn 2015-12-04 8:14 ` Matt Redfearn 2015-12-04 13:14 ` Joshua Kinard
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