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* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* futex: Remove duplicated code and fix undefined behaviourJiri Slaby2017-08-251-22/+4Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is code duplicated over all architecture's headers for futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr, and comparison of the result. Remove this duplication and leave up to the arches only the needed assembly which is now in arch_futex_atomic_op_inuser. This effectively distributes the Will Deacon's arm64 fix for undefined behaviour reported by UBSAN to all architectures. The fix was done in commit 5f16a046f8e1 (arm64: futex: Fix undefined behaviour with FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump. And as suggested by Thomas, check for negative oparg too, because it was also reported to cause undefined behaviour report. Note that s390 removed access_ok check in d12a29703 ("s390/uaccess: remove pointless access_ok() checks") as access_ok there returns true. We introduce it back to the helper for the sake of simplicity (it gets optimized away anyway). Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> [s390] Acked-by: Chris Metcalf <cmetcalf@mellanox.com> [for tile] Reviewed-by: Darren Hart (VMware) <dvhart@infradead.org> Reviewed-by: Will Deacon <will.deacon@arm.com> [core/arm64] Cc: linux-mips@linux-mips.org Cc: Rich Felker <dalias@libc.org> Cc: linux-ia64@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: peterz@infradead.org Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: sparclinux@vger.kernel.org Cc: Jonas Bonn <jonas@southpole.se> Cc: linux-s390@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: linux-hexagon@vger.kernel.org Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: linux-snps-arc@lists.infradead.org Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-xtensa@linux-xtensa.org Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: openrisc@lists.librecores.org Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Stafford Horne <shorne@gmail.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Richard Henderson <rth@twiddle.net> Cc: Chris Zankel <chris@zankel.net> Cc: Michal Simek <monstr@monstr.eu> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-parisc@vger.kernel.org Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: linux-alpha@vger.kernel.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: "David S. Miller" <davem@davemloft.net> Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz
* ARM: uaccess: provide uaccess_save_and_enable() and uaccess_restore()Russell King2015-08-251-2/+17
| | | | | | | | | Provide uaccess_save_and_enable() and uaccess_restore() to permit control of userspace visibility to the kernel, and hook these into the appropriate places in the kernel where we need to access userspace. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* sched/preempt, arm/futex: Disable preemption in UP futex_atomic_op_inuser() ↵David Hildenbrand2015-05-191-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | explicitly The !CONFIG_SMP implementation of futex_atomic_op_inuser() seems to rely on disabled preemption to guarantee mutual exclusion. From commit e589ed23dd27 ("[ARM] 5218/1: arm: improved futex support"): "For UP it's enough to disable preemption to ensure mutual exclusion..." From the code itself: "!SMP, we can work around lack of atomic ops by disabling preemption" Let's make this explicit, to prepare for pagefault_disable() not touching preemption anymore. Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Link: http://lkml.kernel.org/r/1431359540-32227-12-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/preempt, arm/futex: Disable preemption in UP ↵David Hildenbrand2015-05-191-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | futex_atomic_cmpxchg_inatomic() explicitly The !CONFIG_SMP implementation of futex_atomic_cmpxchg_inatomic() requires preemption to be disabled to guarantee mutual exclusion. Let's make this explicit. This patch is based on a patch by Sebastian Andrzej Siewior on the -rt branch. Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Link: http://lkml.kernel.org/r/1431359540-32227-11-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* ARM: 8322/1: keep .text and .fixup regions closer togetherArd Biesheuvel2015-03-301-1/+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: 7984/1: prefetch: add prefetchw invocations for barriered atomicsWill Deacon2014-02-251-0/+3
| | | | | | | | | | | | | After a bunch of benchmarking on the interaction between dmb and pldw, it turns out that issuing the pldw *after* the dmb instruction can give modest performance gains (~3% atomic_add_return improvement on a dual A15). This patch adds prefetchw invocations to our barriered atomic operations including cmpxchg, test_and_xxx and futexes. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 7954/1: mm: remove remaining domain support from ARMv6Will Deacon2014-02-101-6/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPU_32v6 currently selects CPU_USE_DOMAINS if CPU_V6 and MMU. This is because ARM 1136 r0pX CPUs lack the v6k extensions, and therefore do not have hardware thread registers. The lack of these registers requires the kernel to update the vectors page at each context switch in order to write a new TLS pointer. This write must be done via the userspace mapping, since aliasing caches can lead to expensive flushing when using kmap. Finally, this requires the vectors page to be mapped r/w for kernel and r/o for user, which has implications for things like put_user which must trigger CoW appropriately when targetting user pages. The upshot of all this is that a v6/v7 kernel makes use of domains to segregate kernel and user memory accesses. This has the nasty side-effect of making device mappings executable, which has been observed to cause subtle bugs on recent cores (e.g. Cortex-A15 performing a speculative instruction fetch from the GIC and acking an interrupt in the process). This patch solves this problem by removing the remaining domain support from ARMv6. A new memory type is added specifically for the vectors page which allows that page (and only that page) to be mapped as user r/o, kernel r/w. All other user r/o pages are mapped also as kernel r/o. Patch co-developed with Russell King. Cc: <stable@vger.kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 7425/1: extable: ensure fixup entries are 4-byte alignedWill Deacon2012-06-161-0/+1
| | | | | | | | | | | Fixup entries in the kernel exception tables should be 4-byte aligned since we return directly to them when handling a faulting instruction in the kernel. This patch adds the missing align directives to the fixup entries. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 7301/1: Rename the T() macro to TUSER() to avoid namespace conflictsCatalin Marinas2012-01-251-4/+4
| | | | | | | | | This macro is used to generate unprivileged accesses (LDRT/STRT) to user space. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 7099/1: futex: preserve oldval in SMP __futex_atomic_opWill Deacon2011-09-261-17/+17
| | | | | | | | | | | | | | | | The SMP implementation of __futex_atomic_op clobbers oldval with the status flag from the exclusive store. This causes it to always read as zero when performing the FUTEX_OP_CMP_* operation. This patch updates the ARM __futex_atomic_op implementations to take a tmp argument, allowing us to store the strex status flag without overwriting the register containing oldval. Cc: stable@kernel.org Reported-by: Minho Ban <mhban@samsung.com> Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 6889/1: futex: add SMP futex support when !CPU_USE_DOMAINSWill Deacon2011-05-121-47/+90
| | | | | | | | | | | | | This patch uses the load/store exclusive instructions to add SMP futex support for ARM. Since the ARM architecture does not provide instructions for unprivileged exclusive memory accesses, we can only provide SMP futexes when CPU domain support is disabled. Cc: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* arm: Remove bogus comment in futex_atomic_cmpxchg_inatomic()Thomas Gleixner2011-03-141-3/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | commit 522d7dec(futex: Remove redundant pagefault_disable in futex_atomic_cmpxchg_inatomic()) added a bogus comment. /* Note that preemption is disabled by futex_atomic_cmpxchg_inatomic * call sites. */ Bogus in two aspects: 1) pagefault_disable != preempt_disable even if the mechanism we use is the same 2) we have a call site which deliberately does not disable pagefaults as it wants the possible fault to be handled - though that has been changed for consistency reasons now. Sigh. I really should have seen that when committing the above. :( Catched-by-and-rightfully-ranted-at-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <alpine.LFD.2.00.1103141126590.2787@localhost6.localdomain6> Cc: Michel Lespinasse <walken@google.com> Cc: Darren Hart <darren@dvhart.com>
* futex: Sanitize futex ops argument typesMichel Lespinasse2011-03-111-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | Change futex_atomic_op_inuser and futex_atomic_cmpxchg_inatomic prototypes to use u32 types for the futex as this is the data type the futex core code uses all over the place. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Darren Hart <darren@dvhart.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20110311025058.GD26122@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* futex: Sanitize cmpxchg_futex_value_locked APIMichel Lespinasse2011-03-111-8/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cmpxchg_futex_value_locked API was funny in that it returned either the original, user-exposed futex value OR an error code such as -EFAULT. This was confusing at best, and could be a source of livelocks in places that retry the cmpxchg_futex_value_locked after trying to fix the issue by running fault_in_user_writeable(). This change makes the cmpxchg_futex_value_locked API more similar to the get_futex_value_locked one, returning an error code and updating the original value through a reference argument. Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> [tile] Acked-by: Tony Luck <tony.luck@intel.com> [ia64] Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michal Simek <monstr@monstr.eu> [microblaze] Acked-by: David Howells <dhowells@redhat.com> [frv] Cc: Darren Hart <darren@dvhart.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20110311024851.GC26122@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* futex: Remove redundant pagefault_disable in futex_atomic_cmpxchg_inatomic()Michel Lespinasse2011-03-111-3/+2Star
| | | | | | | | | | | | | | | | | | | | | | | | | | kernel/futex.c disables page faults before calling futex_atomic_cmpxchg_inatomic(), so there is no need to do it again within that function. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Darren Hart <darren@dvhart.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20110311024731.GB26122@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ARM: 6384/1: Remove the domain switching on ARMv6k/v7 CPUsCatalin Marinas2010-11-041-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes the domain switching functionality via the set_fs and __switch_to functions on cores that have a TLS register. Currently, the ioremap and vmalloc areas share the same level 1 page tables and therefore have the same domain (DOMAIN_KERNEL). When the kernel domain is modified from Client to Manager (via the __set_fs or in the __switch_to function), the XN (eXecute Never) bit is overridden and newer CPUs can speculatively prefetch the ioremap'ed memory. Linux performs the kernel domain switching to allow user-specific functions (copy_to/from_user, get/put_user etc.) to access kernel memory. In order for these functions to work with the kernel domain set to Client, the patch modifies the LDRT/STRT and related instructions to the LDR/STR ones. The user pages access rights are also modified for kernel read-only access rather than read/write so that the copy-on-write mechanism still works. CPU_USE_DOMAINS gets disabled only if the hardware has a TLS register (CPU_32v6K is defined) since writing the TLS value to the high vectors page isn't possible. The user addresses passed to the kernel are checked by the access_ok() function so that they do not point to the kernel space. Tested-by: Anton Vorontsov <cbouatmailru@gmail.com> Cc: Tony Lindgren <tony@atomide.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: fix build error in arch/arm/kernel/process.cRussell King2010-04-211-8/+8
| | | | | | | | | | | | | | | | | | | | | /tmp/ccJ3ssZW.s: Assembler messages: /tmp/ccJ3ssZW.s:1952: Error: can't resolve `.text' {.text section} - `.LFB1077' This is caused because: .section .data .section .text .section .text .previous does not return us to the .text section, but the .data section; this makes use of .previous dangerous if the ordering of previous sections is not known. Fix up the other users of .previous; .pushsection and .popsection are a safer pairing to use than .section and .previous. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* Thumb-2: Implementation of the unified start-up and exceptions codeCatalin Marinas2009-07-241-0/+1
| | | | | | | This patch implements the ARM/Thumb-2 unified kernel start-up and exception handling code. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* [ARM] 5218/1: arm: improved futex supportMikael Pettersson2008-09-011-3/+121
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux/ARM currently doesn't support robust or PI futexes. The problem is that the kernel wants to perform certain ops (cmpxchg, set, add, or, andn, xor) atomically on user-space addresses, and ARM's futex.h doesn't support that. This patch adds that support, but only for uniprocessor machines. For UP it's enough to disable preemption to ensure mutual exclusion with other software agents (futexes don't need to care about other hardware agents, fortunately). This patch is based on one posted by Khem Raj on 2007-08-01 <http://marc.info/?l=linux-arm-kernel&m=118599407413016&w=2>. (That patch is included in the -RT kernel patches.) My changes since that version include: * corrected implementation of FUTEX_OP_ANDN (must complement oparg) * added missing memory clobber to futex_atomic_cmpxchg_inatomic() * removed spinlock because it's unnecessary for UP and insufficient for SMP, instead the code is restricted to UP and relies on the fact that pagefault_disable() also disables preemption * coding style cleanups Tested on ARMv5 XScales with the glibc-2.6 nptl test suite. Tested-by: Bruce Ashfield <bruce.ashfield@windriver.com> Signed-off-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] move include/asm-arm to arch/arm/include/asmRussell King2008-08-021-0/+6
Move platform independent header files to arch/arm/include/asm, leaving those in asm/arch* and asm/plat* alone. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>