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* arch: Rename CONFIG_DEBUG_RODATA and CONFIG_DEBUG_MODULE_RONXLaura Abbott2017-02-071-4/+4
| | | | | | | | | | | Both of these options are poorly named. The features they provide are necessary for system security and should not be considered debug only. Change the names to CONFIG_STRICT_KERNEL_RWX and CONFIG_STRICT_MODULE_RWX to better describe what these options do. Signed-off-by: Laura Abbott <labbott@redhat.com> Acked-by: Jessica Yu <jeyu@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
* nmi_backtrace: generate one-line reports for idle cpusChris Metcalf2016-10-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | When doing an nmi backtrace of many cores, most of which are idle, the output is a little overwhelming and very uninformative. Suppress messages for cpus that are idling when they are interrupted and just emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN". We do this by grouping all the cpuidle code together into a new .cpuidle.text section, and then checking the address of the interrupted PC to see if it lies within that section. This commit suitably tags x86 and tile idle routines, and only adds in the minimal framework for other architectures. Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.com Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm] Tested-by: Petr Mladek <pmladek@suse.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arm: jump label may reference text in __exitJason Baron2016-08-041-1/+1
| | | | | | | | | | | | | | | | | | | | | The jump table can reference text found in an __exit section. Thus, instead of discarding it at build time, include EXIT_TEXT as part of __init and it will be released when the system boots. Link: http://lkml.kernel.org/r/60284113bb759121e8ae3e99af1535647e52123f.1467837322.git.jbaron@akamai.com Signed-off-by: Jason Baron <jbaron@akamai.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Joe Perches <joe@perches.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ARM: 8583/1: mm: fix location of _etextKees Cook2016-07-021-2/+2
| | | | | | | | | | | The _etext position is defined to be the end of the kernel text code, and should not include any part of the data segments. This interferes with things that might check memory ranges and expect executable code up to _etext. Just to be conservative, leave the kernel resource as it was, using __init_begin instead of _etext as the end mark. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* arch, ftrace: for KASAN put hard/soft IRQ entries into separate sectionsAlexander Potapenko2016-03-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | KASAN needs to know whether the allocation happens in an IRQ handler. This lets us strip everything below the IRQ entry point to reduce the number of unique stack traces needed to be stored. Move the definition of __irq_entry to <linux/interrupt.h> so that the users don't need to pull in <linux/ftrace.h>. Also introduce the __softirq_entry macro which is similar to __irq_entry, but puts the corresponding functions to the .softirqentry.text section. Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-armLinus Torvalds2016-03-191-34/+26
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull ARM updates from Russell King: "Another mixture of changes this time around: - Split XIP linker file from main linker file to make it more maintainable, and various XIP fixes, and clean up a resulting macro. - Decompressor cleanups from Masahiro Yamada - Avoid printing an error for a missing L2 cache - Remove some duplicated symbols in System.map, and move vectors/stubs back into kernel VMA - Various low priority fixes from Arnd - Updates to allow bus match functions to return negative errno values, touching some drivers and the driver core. Greg has acked these changes. - Virtualisation platform udpates form Jean-Philippe Brucker. - Security enhancements from Kees Cook - Rework some Kconfig dependencies and move PSCI idle management code out of arch/arm into drivers/firmware/psci.c - ARM DMA mapping updates, touching media, acked by Mauro. - Fix places in ARM code which should be using virt_to_idmap() so that Keystone2 can work. - Fix Marvell Tauros2 to work again with non-DT boots. - Provide a delay timer for ARM Orion platforms" * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (45 commits) ARM: 8546/1: dma-mapping: refactor to fix coherent+cma+gfp=0 ARM: 8547/1: dma-mapping: store buffer information ARM: 8543/1: decompressor: rename suffix_y to compress-y ARM: 8542/1: decompressor: merge piggy.*.S and simplify Makefile ARM: 8541/1: decompressor: drop redundant FORCE in Makefile ARM: 8540/1: decompressor: use clean-files instead of extra-y to clean files ARM: 8539/1: decompressor: drop more unneeded assignments to "targets" ARM: 8538/1: decompressor: drop unneeded assignments to "targets" ARM: 8532/1: uncompress: mark putc as inline ARM: 8531/1: turn init_new_context into an inline function ARM: 8530/1: remove VIRT_TO_BUS ARM: 8537/1: drop unused DEBUG_RODATA from XIP_KERNEL ARM: 8536/1: mm: hide __start_rodata_section_aligned for non-debug builds ARM: 8535/1: mm: DEBUG_RODATA makes no sense with XIP_KERNEL ARM: 8534/1: virt: fix hyp-stub build for pre-ARMv7 CPUs ARM: make the physical-relative calculation more obvious ARM: 8512/1: proc-v7.S: Adjust stack address when XIP_KERNEL ARM: 8411/1: Add default SPARSEMEM settings ARM: 8503/1: clk_register_clkdev: remove format string interface ARM: 8529/1: remove 'i' and 'zi' targets ...
| * ARM: 8536/1: mm: hide __start_rodata_section_aligned for non-debug buildsArnd Bergmann2016-02-221-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __start_rodata_section_aligned is only referenced by the DEBUG_RODATA code, which is only used when the MMU is enabled, but the definition fails on !MMU builds: arch/arm/kernel/vmlinux.lds:702: undefined symbol `SECTION_SHIFT' referenced in expression This hides the symbol whenever DEBUG_RODATA is disabled. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 64ac2e74f0b2 ("ARM: 8502/1: mm: mark section-aligned portion of rodata NX") Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * ARM: 8502/1: mm: mark section-aligned portion of rodata NXKees Cook2016-02-111-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When rodata is large enough that it crosses a section boundary after the kernel text, mark the rest NX. This is as close to full NX of rodata as we can get without splitting page tables or doing section alignment via CONFIG_DEBUG_ALIGN_RODATA. When the config is: CONFIG_DEBUG_RODATA=y # CONFIG_DEBUG_ALIGN_RODATA is not set Before: ---[ Kernel Mapping ]--- 0x80000000-0x80100000 1M RW NX SHD 0x80100000-0x80a00000 9M ro x SHD 0x80a00000-0xa0000000 502M RW NX SHD After: ---[ Kernel Mapping ]--- 0x80000000-0x80100000 1M RW NX SHD 0x80100000-0x80700000 6M ro x SHD 0x80700000-0x80a00000 3M ro NX SHD 0x80a00000-0xa0000000 502M RW NX SHD Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * ARM: 8515/2: move .vectors and .stubs sections back into the kernel VMAArd Biesheuvel2016-02-111-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b9b32bf70f2f ("ARM: use linker magic for vectors and vector stubs") updated the linker script to emit the .vectors and .stubs sections into a VMA range that is zero based and disjoint from the normal static kernel region. The reason for that was that this way, the sections can be placed exactly 4 KB apart, while the payload of the .vectors section is only 32 bytes. Since the symbols that are part of the .stubs section are emitted into the kallsyms table, they appear with zero based addresses as well, e.g., 00001004 t vector_rst 00001020 t vector_irq 000010a0 t vector_dabt 00001120 t vector_pabt 000011a0 t vector_und 00001220 t vector_addrexcptn 00001240 t vector_fiq 00001240 T vector_fiq_offset As this confuses perf when it accesses the kallsyms tables, commit 7122c3e9154b ("scripts/link-vmlinux.sh: only filter kernel symbols for arm") implemented a somewhat ugly special case for ARM, where the value of CONFIG_PAGE_OFFSET is passed to scripts/kallsyms, and symbols whose addresses are below it are filtered out. Note that this special case only applies to CONFIG_XIP_KERNEL=n, not because the issue the patch addresses exists only in that case, but because finding a limit below which to apply the filtering is not entirely straightforward. Since the .vectors and .stubs sections contain position independent code that is never executed in place, we can emit it at its most likely runtime VMA (for more recent CPUs), which is 0xffff0000 for the vector table and 0xffff1000 for the stubs. Not only does this fix the perf issue with kallsyms, allowing us to drop the special case in scripts/kallsyms entirely, it also gives debuggers a more realistic view of the address space, and setting breakpoints or single stepping through code in the vector table or the stubs is more likely to work as expected on CPUs that use a high vector address. E.g., 00001240 A vector_fiq_offset ... c0c35000 T __init_begin c0c35000 T __vectors_start c0c35020 T __stubs_start c0c35020 T __vectors_end c0c352e0 T _sinittext c0c352e0 T __stubs_end ... ffff1004 t vector_rst ffff1020 t vector_irq ffff10a0 t vector_dabt ffff1120 t vector_pabt ffff11a0 t vector_und ffff1220 t vector_addrexcptn ffff1240 T vector_fiq (Note that vector_fiq_offset is now an absolute symbol, which kallsyms already ignores by default) The LMA footprint is identical with or without this change, only the VMAs are different: Before: Idx Name Size VMA LMA File off Algn ... 14 .notes 00000024 c0c34020 c0c34020 00a34020 2**2 CONTENTS, ALLOC, LOAD, READONLY, CODE 15 .vectors 00000020 00000000 c0c35000 00a40000 2**1 CONTENTS, ALLOC, LOAD, READONLY, CODE 16 .stubs 000002c0 00001000 c0c35020 00a41000 2**5 CONTENTS, ALLOC, LOAD, READONLY, CODE 17 .init.text 0006b1b8 c0c352e0 c0c352e0 00a452e0 2**5 CONTENTS, ALLOC, LOAD, READONLY, CODE ... After: Idx Name Size VMA LMA File off Algn ... 14 .notes 00000024 c0c34020 c0c34020 00a34020 2**2 CONTENTS, ALLOC, LOAD, READONLY, CODE 15 .vectors 00000020 ffff0000 c0c35000 00a40000 2**1 CONTENTS, ALLOC, LOAD, READONLY, CODE 16 .stubs 000002c0 ffff1000 c0c35020 00a41000 2**5 CONTENTS, ALLOC, LOAD, READONLY, CODE 17 .init.text 0006b1b8 c0c352e0 c0c352e0 00a452e0 2**5 CONTENTS, ALLOC, LOAD, READONLY, CODE ... Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Chris Brandt <chris.brandt@renesas.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * ARM: 8513/1: xip: Move XIP linking to a separate fileChris Brandt2016-02-111-27/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building an XIP kernel, the linker script needs to be much different than a conventional kernel's script. Over time, it's been difficult to maintain both XIP and non-XIP layouts in one linker script. Therefore, this patch separates the two procedures into two completely different files. The new linker script is essentially a straight copy of the current script with all the non-CONFIG_XIP_KERNEL portions removed. Additionally, all CONFIG_XIP_KERNEL portions have been removed from the existing linker script...never to return again. It should be noted that this does not fix any current XIP issues, but rather is the first move in fixing them properly with subsequent patches. Signed-off-by: Chris Brandt <chris.brandt@renesas.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * ARM: 8501/1: mm: flip priority of CONFIG_DEBUG_RODATAKees Cook2016-02-081-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The use of CONFIG_DEBUG_RODATA is generally seen as an essential part of kernel self-protection: http://www.openwall.com/lists/kernel-hardening/2015/11/30/13 Additionally, its name has grown to mean things beyond just rodata. To get ARM closer to this, we ought to rearrange the names of the configs that control how the kernel protects its memory. What was called CONFIG_ARM_KERNMEM_PERMS is realy doing the work that other architectures call CONFIG_DEBUG_RODATA. This redefines CONFIG_DEBUG_RODATA to actually do the bulk of the ROing (and NXing). In the place of the old CONFIG_DEBUG_RODATA, use CONFIG_DEBUG_ALIGN_RODATA, since that's what the option does: adds section alignment for making rodata explicitly NX, as arm does not split the page tables like arm64 does without _ALIGN_RODATA. Also adds human readable names to the sections so I could more easily debug my typos, and makes CONFIG_DEBUG_RODATA default "y" for CPU_V7. Results in /sys/kernel/debug/kernel_page_tables for each config state: # CONFIG_DEBUG_RODATA is not set # CONFIG_DEBUG_ALIGN_RODATA is not set ---[ Kernel Mapping ]--- 0x80000000-0x80900000 9M RW x SHD 0x80900000-0xa0000000 503M RW NX SHD CONFIG_DEBUG_RODATA=y CONFIG_DEBUG_ALIGN_RODATA=y ---[ Kernel Mapping ]--- 0x80000000-0x80100000 1M RW NX SHD 0x80100000-0x80700000 6M ro x SHD 0x80700000-0x80a00000 3M ro NX SHD 0x80a00000-0xa0000000 502M RW NX SHD CONFIG_DEBUG_RODATA=y # CONFIG_DEBUG_ALIGN_RODATA is not set ---[ Kernel Mapping ]--- 0x80000000-0x80100000 1M RW NX SHD 0x80100000-0x80a00000 9M ro x SHD 0x80a00000-0xa0000000 502M RW NX SHD Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | ARM: KVM: Move the HYP code to its own sectionMarc Zyngier2016-02-291-0/+6
|/ | | | | | | | | | | | | In order to be able to spread the HYP code into multiple compilation units, adopt a layout similar to that of arm64: - the HYP text is emited in its own section (.hyp.text) - two linker generated symbols are use to identify the boundaries of that section No functionnal change. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* Merge tag 'arm64-upstream' of ↵Linus Torvalds2015-04-161-4/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "Here are the core arm64 updates for 4.1. Highlights include a significant rework to head.S (allowing us to boot on machines with physical memory at a really high address), an AES performance boost on Cortex-A57 and the ability to run a 32-bit userspace with 64k pages (although this requires said userspace to be built with a recent binutils). The head.S rework spilt over into KVM, so there are some changes under arch/arm/ which have been acked by Marc Zyngier (KVM co-maintainer). In particular, the linker script changes caused us some issues in -next, so there are a few merge commits where we had to apply fixes on top of a stable branch. Other changes include: - AES performance boost for Cortex-A57 - AArch32 (compat) userspace with 64k pages - Cortex-A53 erratum workaround for #845719 - defconfig updates (new platforms, PCI, ...)" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (39 commits) arm64: fix midr range for Cortex-A57 erratum 832075 arm64: errata: add workaround for cortex-a53 erratum #845719 arm64: Use bool function return values of true/false not 1/0 arm64: defconfig: updates for 4.1 arm64: Extract feature parsing code from cpu_errata.c arm64: alternative: Allow immediate branch as alternative instruction arm64: insn: Add aarch64_insn_decode_immediate ARM: kvm: round HYP section to page size instead of log2 upper bound ARM: kvm: assert on HYP section boundaries not actual code size arm64: head.S: ensure idmap_t0sz is visible arm64: pmu: add support for interrupt-affinity property dt: pmu: extend ARM PMU binding to allow for explicit interrupt affinity arm64: head.S: ensure visibility of page tables arm64: KVM: use ID map with increased VA range if required arm64: mm: increase VA range of identity map ARM: kvm: implement replacement for ld's LOG2CEIL() arm64: proc: remove unused cpu_get_pgd macro arm64: enforce x1|x2|x3 == 0 upon kernel entry as per boot protocol arm64: remove __calc_phys_offset arm64: merge __enable_mmu and __turn_mmu_on ...
| * ARM: kvm: round HYP section to page size instead of log2 upper boundArd Biesheuvel2015-03-271-30/+1
| | | | | | | | | | | | | | | | | | | | Older binutils do not support expressions involving the values of external symbols so just round up the HYP region to the page size. Tested-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: when will this ever end?!] Signed-off-by: Will Deacon <will.deacon@arm.com>
| * ARM: kvm: assert on HYP section boundaries not actual code sizeArd Biesheuvel2015-03-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using ASSERT() with an expression that involves a symbol that is only supplied through a PROVIDE() definition in the linker script itself is apparently not supported by some older versions of binutils. So instead, rewrite the expression so that only the section boundaries __hyp_idmap_text_start and __hyp_idmap_text_end are used. Note that this reverts the fix in 06f75a1f6200 ("ARM, arm64: kvm: get rid of the bounce page") for the ASSERT() being triggered erroneously when unrelated linker emitted veneers happen to end up in the HYP idmap region. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
| * ARM: kvm: implement replacement for ld's LOG2CEIL()Ard Biesheuvel2015-03-231-2/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 06f75a1f6200 ("ARM, arm64: kvm: get rid of the bounce page") uses ld's builtin function LOG2CEIL() to align the KVM init code to a log2 upper bound of its size. However, this function turns out to be a fairly recent addition to binutils, which breaks the build for older toolchains. So instead, implement a replacement LOG2_ROUNDUP() using the C preprocessor. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
| * ARM, arm64: kvm: get rid of the bounce pageArd Biesheuvel2015-03-191-3/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The HYP init bounce page is a runtime construct that ensures that the HYP init code does not cross a page boundary. However, this is something we can do perfectly well at build time, by aligning the code appropriately. For arm64, we just align to 4 KB, and enforce that the code size is less than 4 KB, regardless of the chosen page size. For ARM, the whole code is less than 256 bytes, so we tweak the linker script to align at a power of 2 upper bound of the code size Note that this also fixes a benign off-by-one error in the original bounce page code, where a bounce page would be allocated unnecessarily if the code was exactly 1 page in size. On ARM, it also fixes an issue with very large kernels reported by Arnd Bergmann, where stub sections with linker emitted veneers could erroneously trigger the size/alignment ASSERT() in the linker script. Tested-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
* | ARM: 8322/1: keep .text and .fixup regions closer togetherArd Biesheuvel2015-03-291-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | This moves all fixup snippets to the .text.fixup section, which is a special section that gets emitted along with the .text section for each input object file, i.e., the snippets are kept much closer to the code they refer to, which helps prevent linker failure on large kernels. Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | ARM: 8317/1: move the .idmap.text section closer to .head.textArd Biesheuvel2015-03-281-1/+1
|/ | | | | | | | | | This moves the .idmap.text section closer to .head.text, so that relative branches are less likely to go out of range if the kernel text gets bigger. Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* Merge tag 'ronx-next' of ↵Russell King2014-11-031-0/+19
|\ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux into devel-stable generic fixmaps ARM support for CONFIG_DEBUG_RODATA
| * ARM: mm: allow text and rodata sections to be read-onlyKees Cook2014-10-161-0/+3
| | | | | | | | | | | | | | | | | | | | | | This introduces CONFIG_DEBUG_RODATA, making kernel text and rodata read-only. Additionally, this splits rodata from text so that rodata can also be NX, which may lead to wasted memory when aligning to SECTION_SIZE. The read-only areas are made writable during ftrace updates and kexec. Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Laura Abbott <lauraa@codeaurora.org> Acked-by: Nicolas Pitre <nico@linaro.org>
| * ARM: mm: allow non-text sections to be non-executableKees Cook2014-10-161-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adds CONFIG_ARM_KERNMEM_PERMS to separate the kernel memory regions into section-sized areas that can have different permisions. Performs the NX permission changes during free_initmem, so that init memory can be reclaimed. This uses section size instead of PMD size to reduce memory lost to padding on non-LPAE systems. Based on work by Brad Spengler, Larry Bassel, and Laura Abbott. Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Laura Abbott <lauraa@codeaurora.org> Acked-by: Nicolas Pitre <nico@linaro.org>
* | ARM: 8168/1: extend __init_end to a page align addressYalin Wang2014-10-021-1/+1
|/ | | | | | | | | | | | | This patch changes the __init_end address to a page align address, so that free_initmem() can free the whole .init section, because if the end address is not page aligned, it will round down to a page align address, then the tail unligned page will not be freed. Signed-off-by: wang <yalin.wang2010@gmail.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 8088/1: vmlinux.lds.S: drop redundant .commentMark Rutland2014-07-181-1/+0
| | | | | | | | | | | | | Commit 78d7530ac3 ("ARM: Clean up linker script using new linker script macros.") modified the arm kernel linker script to use the STABS_DEBUG macro, but left a .comment section definition. As STABS_DEBUG defines the .comment section in an identical way, the second section definition is redundant and can be removed. This patch removes the redundant .comment section definition. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: use linker magic for vectors and vector stubsRussell King2013-07-311-0/+17
| | | | | | | | | | | Use linker magic to create the vectors and vector stubs: we can tell the linker to place them at an appropriate VMA, but keep the LMA within the kernel. This gets rid of some unnecessary symbol manipulation, and have the linker calculate the relocations appropriately. Cc: <stable@vger.kernel.org> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* Finally eradicate CONFIG_HOTPLUGStephen Rothwell2013-06-031-4/+0
| | | | | | | | | | | | | | | | | | | Ever since commit 45f035ab9b8f ("CONFIG_HOTPLUG should be always on"), it has been basically impossible to build a kernel with CONFIG_HOTPLUG turned off. Remove all the remaining references to it. Cc: Russell King <linux@arm.linux.org.uk> Cc: Doug Thompson <dougthompson@xmission.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ARM: KVM: enforce maximum size for identity mapped codeMarc Zyngier2013-04-281-1/+6
| | | | | | | | | | We're about to move to an init procedure where we rely on the fact that the init code fits in a single page. Make sure we align the idmap text on a vector alignment, and that the code is not bigger than a single page. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
* ARM: Section based HYP idmapChristoffer Dall2013-01-231-1/+5
| | | | | | | | | | | | | | | | Add a method (hyp_idmap_setup) to populate a hyp pgd with an identity mapping of the code contained in the .hyp.idmap.text section. Offer a method to drop this identity mapping through hyp_idmap_teardown. Make all the above depend on CONFIG_ARM_VIRT_EXT and CONFIG_ARM_LPAE. Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
* ARM: 7605/1: vmlinux.lds: Move .notes section next to the rodataPawel Moll2012-12-161-2/+2
| | | | | | | | | | | | | | | The .notes, being read-only data by nature, were placed between read-write .data and .bss. This was harmful in case of the XIP kernel, as being placed in the RAM range, most likely far from the ROM address, was inflating the XIP images. Moving the .notes at the end of the read-only section (consisting of .text, .rodata and unwind info) fixes the problem. Reported-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Pawel Moll <pawel.moll@arm.com> Tested-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 7568/1: Sort exception table at compile timeStephen Boyd2012-11-041-10/+9
| | | | | | | | | | | | | | | | Add the ARM machine identifier to sortextable and select the config option so that we can sort the exception table at compile time. sortextable relies on a section named __ex_table existing in the vmlinux, but ARM's linker script places the exception table in the data section. Give the exception table its own section so that sortextable can find it. This allows us to skip the sorting step during boot. Cc: David Daney <david.daney@cavium.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 7428/1: Prevent KALLSYM size mismatch on ARM.David Brown2012-06-221-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ARM builds seem to be plagued by an occasional build error: Inconsistent kallsyms data This is a bug - please report about it Try "make KALLSYMS_EXTRA_PASS=1" as a workaround The problem has to do with alignment of some sections by the linker. The kallsyms data is built in two passes by first linking the kernel without it, and then linking the kernel again with the symbols included. Normally, this just shifts the symbols, without changing their order, and the compression used by the kallsyms gives the same result. On non SMP, the per CPU data is empty. Depending on the where the alignment ends up, it can come out as either: +-------------------+ | last text segment | +-------------------+ /* padding */ +-------------------+ <- L1_CACHE_BYTES alignemnt | per cpu (empty) | +-------------------+ __per_cpu_end: /* padding */ __data_loc: +-------------------+ <- THREAD_SIZE alignment | data | +-------------------+ or +-------------------+ | last text segment | +-------------------+ /* padding */ +-------------------+ <- L1_CACHE_BYTES alignemnt | per cpu (empty) | +-------------------+ __per_cpu_end: /* no padding */ __data_loc: +-------------------+ <- THREAD_SIZE alignment | data | +-------------------+ if the alignment satisfies both. Because symbols that have the same address are sorted by 'nm -n', the second case will be in a different order than the first case. This changes the compression, changing the size of the kallsym data, causing the build failure. The KALLSYMS_EXTRA_PASS=1 workaround usually works, but it is still possible to have the alignment change between the second and third pass. It's probably even possible for it to never reach a fixedpoint. The problem only occurs on non-SMP, when the per-cpu data is empty, and when the data segment has alignment (and immediately follows the text segments). Fix this by only including the per_cpu section on SMP, when it is not empty. Signed-off-by: David Brown <davidb@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 7320/1: Fix proc_info table alignmentMarc Zyngier2012-02-091-0/+1
| | | | | | | | | | | | | | With an admittedly exotic choice of configuration options (CC_OPTIMIZE_FOR_SIZE, THUMB2, some other size-minimizing ones) and compiler, the proc_info table can end up being misaligned, and the kernel being unbootable (Error: unrecognized/unsupported processor variant). Forcing the alignement to 4 bytes in the linker script fixes the issue. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 7290/1: vmlinux.lds.S: align the exception fixup table to a 4-byte boundaryWill Deacon2012-01-231-1/+1
| | | | | | | | | | | | | | The exception fixup table is currently aligned to a 32-byte boundary. Whilst this won't cause any problems, the exception_table_entry structures contain only a pair of unsigned longs, so 4-byte alignment is all that is required. If the table was walked from start to end, cacheline alignment may bring some performance benefits, but since a binary search is used, the access pattern is random and will not benefit from a stricter alignment. Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 7289/1: vmlinux.lds.S: do not hardcode cacheline size as 32 bytesWill Deacon2012-01-231-3/+4
| | | | | | | | | | | The linker script assumes a cacheline size of 32 bytes when aligning the .data..cacheline_aligned and .data..percpu sections. This patch updates the script to use L1_CACHE_BYTES, which should be set to 64 on platforms that require it. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: idmap: populate identity map pgd at init time using .init.textWill Deacon2011-12-061-0/+7
| | | | | | | | | | | | | | | | | | When disabling and re-enabling the MMU, it is necessary to take out an identity mapping for the code that manipulates the SCTLR in order to avoid it disappearing from under our feet. This is useful when soft rebooting and returning from CPU suspend. This patch allocates a set of page tables during boot and populates them with an identity mapping for the .idmap.text section. This means that users of the identity map do not need to manage their own pgd and can instead annotate their functions with __idmap or, in the case of assembly code, place them in the correct section. Acked-by: Dave Martin <dave.martin@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* Merge branch 'misc' into for-linusRussell King2011-10-251-1/+2
|\ | | | | | | | | Conflicts: arch/arm/mach-integrator/integrator_ap.c
| * ARM: 7017/1: Use generic BUG() handlerSimon Glass2011-10-171-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ARM uses its own BUG() handler which makes its output slightly different from other archtectures. One of the problems is that the ARM implementation doesn't report the function with the BUG() in it, but always reports the PC being in __bug(). The generic implementation doesn't have this problem. Currently we get something like: kernel BUG at fs/proc/breakme.c:35! Unable to handle kernel NULL pointer dereference at virtual address 00000000 ... PC is at __bug+0x20/0x2c With this patch it displays: kernel BUG at fs/proc/breakme.c:35! Internal error: Oops - undefined instruction: 0 [#1] PREEMPT SMP ... PC is at write_breakme+0xd0/0x1b4 This implementation uses an undefined instruction to implement BUG, and sets up a bug table containing the relevant information. Many versions of gcc do not support %c properly for ARM (inserting a # when they shouldn't) so we work around this using distasteful macro magic. v1: Initial version to replace existing ARM BUG() implementation with something more similar to other architectures. v2: Add Thumb support, remove backtrace whitespace output changes. Change to use macros instead of requiring the asm %d flag to work (thanks to Dave Martin <dave.martin@linaro.org>) v3: Remove old BUG() implementation in favor of this one. Remove the Backtrace: message (will submit this separately). Use ARM_EXIT_KEEP() so that some architectures can dump exit text at link time thanks to Stephen Boyd <sboyd@codeaurora.org> (although since we always define GENERIC_BUG this might be academic.) Rebase to linux-2.6.git master. v4: Allow BUGS in modules (these were not reported correctly in v3) (thanks to Stephen Boyd <sboyd@codeaurora.org> for suggesting that.) Remove __bug() as this is no longer needed. v5: Add %progbits as the section flags. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | ARM: fix vmlinux.lds.S discarding sectionsRussell King2011-09-201-3/+12
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are seeing linker errors caused by sections being discarded, despite the linker script trying to keep them. The result is (eg): `.exit.text' referenced in section `.alt.smp.init' of drivers/built-in.o: defined in discarded section `.exit.text' of drivers/built-in.o `.exit.text' referenced in section `.alt.smp.init' of net/built-in.o: defined in discarded section `.exit.text' of net/built-in.o This is the relevent part of the linker script (reformatted to make it clearer): | SECTIONS | { | /* | * unwind exit sections must be discarded before the rest of the | * unwind sections get included. | */ | /DISCARD/ : { | *(.ARM.exidx.exit.text) | *(.ARM.extab.exit.text) | } | ... | .exit.text : { | *(.exit.text) | *(.memexit.text) | } | ... | /DISCARD/ : { | *(.exit.text) | *(.memexit.text) | *(.exit.data) | *(.memexit.data) | *(.memexit.rodata) | *(.exitcall.exit) | *(.discard) | *(.discard.*) | } | } Now, this is what the linker manual says about discarded output sections: | The special output section name `/DISCARD/' may be used to discard | input sections. Any input sections which are assigned to an output | section named `/DISCARD/' are not included in the output file. No questions, no exceptions. It doesn't say "unless they are listed before the /DISCARD/ section." Now, this is what asn-generic/vmlinux.lds.S says: | /* | * Default discarded sections. | * | * Some archs want to discard exit text/data at runtime rather than | * link time due to cross-section references such as alt instructions, | * bug table, eh_frame, etc. DISCARDS must be the last of output | * section definitions so that such archs put those in earlier section | * definitions. | */ And guess what - the list _always_ includes .exit.text etc. Now, what's actually happening is that the linker is reading the script, and it finds the first /DISCARD/ output section at the beginning of the script. It continues reading the script, and finds the 'DISCARD' macro at the end, which having been postprocessed results in another /DISCARD/ output section. As the linker already contains the earlier /DISCARD/ output section, it adds it to that existing section, so it effectively is placed at the start. This can be seen by using the -M option to ld: | Linker script and memory map | | 0xc037c080 jiffies = jiffies_64 | | /DISCARD/ | *(.ARM.exidx.exit.text) | *(.ARM.extab.exit.text) | *(.exit.text) | *(.memexit.text) | *(.exit.data) | *(.memexit.data) | *(.memexit.rodata) | *(.exitcall.exit) | *(.discard) | *(.discard.*) | | 0xc0008000 . = 0xc0008000 | | .head.text 0xc0008000 0x1d0 | 0xc0008000 _text = . | *(.head.text) | .head.text 0xc0008000 0x1d0 arch/arm/kernel/head.o | 0xc0008000 stext | | .text 0xc0008200 0x2d78d0 | 0xc0008200 _stext = . | 0xc0008200 __exception_text_start = . | *(.exception.text) | .exception.text | ... As you can see, all the discarded sections are grouped together - and as a result of it being the first output section, they all appear before any other section. The result is that not only is the unwind information discarded (as intended), but also the .exit.text, despite us wanting to have the .exit.text preserved. We can't move the unwind information elsewhere, because it'll then be included even when we do actually discard the .exit.text (and similar) sections. So, work around this by avoiding the generic DISCARDS macro, and instead conditionalize the sections to be discarded ourselves. This avoids the ambiguity in how the linker assigns input sections to output sections, making our script less dependent on undocumented linker behaviour. Reported-by: Rob Herring <robherring2@gmail.com> Tested-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: vmlinux.lds: use _text and _stext the same way as x86Russell King2011-07-071-2/+2
| | | | | | | | | | | | x86 uses _text to mark the start of the kernel image including the head text, and _stext to mark the start of the .text section. Change our vmlinux.lds to conform. An audit of the places which use _stext and _text in arch/arm indicates no users of either symbol are impacted by this change. It does mean a slight change to /proc/iomem output. Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: vmlinux.lds: move init sections between text and data sectionsRussell King2011-07-071-48/+48
| | | | | | | | | | | | Place the init sections between the text and data sections. This means all code is grouped together at the beginning of the kernel image, and all data is at the end of the image. This avoids problems with the 24-bit branch instruction relocations becoming invalid with large initramfs images. Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: vmlinux.lds: remove .rodata/.rodata1 from main .text segmentRussell King2011-07-071-2/+0
| | | | | | | | | RODATA() already handles these sections, so allow it to take care of them for us. Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: vmlinux.lds: rearrange .init output sectionRussell King2011-07-071-18/+29
| | | | | | | | | | Keep the various linker tables as separate output sections rather than combining them together into one big .init section. This makes the 'vmlinux' easier to see what is placed where. Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: vmlinux.lds: move discarded sections to beginningRussell King2011-07-071-25/+22
| | | | | | | | | Rather than scattering the discarded sections throughout the linker file, move them to the start. Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* percpu: Always align percpu output section to PAGE_SIZETejun Heo2011-03-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Percpu allocator honors alignment request upto PAGE_SIZE and both the percpu addresses in the percpu address space and the translated kernel addresses should be aligned accordingly. The calculation of the former depends on the alignment of percpu output section in the kernel image. The linker script macros PERCPU_VADDR() and PERCPU() are used to define this output section and the latter takes @align parameter. Several architectures are using @align smaller than PAGE_SIZE breaking percpu memory alignment. This patch removes @align parameter from PERCPU(), renames it to PERCPU_SECTION() and makes it always align to PAGE_SIZE. While at it, add PCPU_SETUP_BUG_ON() checks such that alignment problems are reliably detected and remove percpu alignment comment recently added in workqueue.c as the condition would trigger BUG way before reaching there. For um, this patch raises the alignment of percpu area. As the area is in .init, there shouldn't be any noticeable difference. This problem was discovered by David Howells while debugging boot failure on mn10300. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Mike Frysinger <vapier@gentoo.org> Cc: uclinux-dist-devel@blackfin.uclinux.org Cc: David Howells <dhowells@redhat.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: user-mode-linux-devel@lists.sourceforge.net
* Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds2011-03-161-0/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (91 commits) ARM: 6806/1: irq: introduce entry and exit functions for chained handlers ARM: 6781/1: Thumb-2: Work around buggy Thumb-2 short branch relocations in gas ARM: 6747/1: P2V: Thumb2 support ARM: 6798/1: aout-core: zero thread debug registers in a.out core dump ARM: 6796/1: Footbridge: Fix I/O mappings for NOMMU mode ARM: 6784/1: errata: no automatic Store Buffer drain on Cortex-A9 ARM: 6772/1: errata: possible fault MMU translations following an ASID switch ARM: 6776/1: mach-ux500: activate fix for errata 753970 ARM: 6794/1: SPEAr: Append UL to device address macros. ARM: 6793/1: SPEAr: Remove unused *_SIZE macros from spear*.h files ARM: 6792/1: SPEAr: Replace SIZE macro's with SZ_4K macros ARM: 6791/1: SPEAr3xx: Declare device structures after shirq code ARM: 6790/1: SPEAr: Clock Framework: Rename usbd clock and align apb_clk entry ARM: 6789/1: SPEAr3xx: Rename sdio to sdhci ARM: 6788/1: SPEAr: Include mach/hardware.h instead of mach/spear.h ARM: 6787/1: SPEAr: Reorder #includes in .h & .c files. ARM: 6681/1: SPEAr: add debugfs support to clk API ARM: 6703/1: SPEAr: update clk API support ARM: 6679/1: SPEAr: make clk API functions more generic ARM: 6737/1: SPEAr: formalized timer support ...
| * Merge branch 'p2v' into develRussell King2011-03-161-0/+4
| |\ | | | | | | | | | | | | | | | Conflicts: arch/arm/kernel/module.c arch/arm/mach-s5pv210/sleep.S
| | * ARM: P2V: introduce phys_to_virt/virt_to_phys runtime patchingRussell King2011-02-171-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This idea came from Nicolas, Eric Miao produced an initial version, which was then rewritten into this. Patch the physical to virtual translations at runtime. As we modify the code, this makes it incompatible with XIP kernels, but allows us to achieve this with minimal loss of performance. As many translations are of the form: physical = virtual + (PHYS_OFFSET - PAGE_OFFSET) virtual = physical - (PHYS_OFFSET - PAGE_OFFSET) we generate an 'add' instruction for __virt_to_phys(), and a 'sub' instruction for __phys_to_virt(). We calculate at run time (PHYS_OFFSET - PAGE_OFFSET) by comparing the address prior to MMU initialization with where it should be once the MMU has been initialized, and place this constant into the above add/sub instructions. Once we have (PHYS_OFFSET - PAGE_OFFSET), we can calculate the real PHYS_OFFSET as PAGE_OFFSET is a build-time constant, and save this for the C-mode PHYS_OFFSET variable definition to use. At present, we are unable to support Realview with Sparsemem enabled as this uses a complex mapping function, and MSM as this requires a constant which will not fit in our math instruction. Add a module version magic string for this feature to prevent incompatible modules being loaded. Tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | | Merge branch 'for-2.6.39' of ↵Linus Torvalds2011-03-161-1/+1
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu, x86: Add arch-specific this_cpu_cmpxchg_double() support percpu: Generic support for this_cpu_cmpxchg_double() alpha: use L1_CACHE_BYTES for cacheline size in the linker script percpu: align percpu readmostly subsection to cacheline Fix up trivial conflict in arch/x86/kernel/vmlinux.lds.S due to the percpu alignment having changed ("x86: Reduce back the alignment of the per-CPU data section")
| * | percpu: align percpu readmostly subsection to cachelineTejun Heo2011-01-251-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently percpu readmostly subsection may share cachelines with other percpu subsections which may result in unnecessary cacheline bounce and performance degradation. This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR() linker macros, makes each arch linker scripts specify its cacheline size and use it to align percpu subsections. This is based on Shaohua's x86 only patch. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Shaohua Li <shaohua.li@intel.com>
* | ARM: Keep exit text/data around for SMP_ON_UPRussell King2011-02-211-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | When SMP_ON_UP is used and the spinlocks are inlined, we end up with inline spinlocks in the exit code, with references from the SMP alternatives section to the exit sections. This causes link time errors. Avoid this by placing the exit sections in the init-discarded region. Cc: <stable@kernel.org> Tested-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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