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2016-01-14mm: mmap: add new /proc tunable for mmap_base ASLRDaniel Cashman
Address Space Layout Randomization (ASLR) provides a barrier to exploitation of user-space processes in the presence of security vulnerabilities by making it more difficult to find desired code/data which could help an attack. This is done by adding a random offset to the location of regions in the process address space, with a greater range of potential offset values corresponding to better protection/a larger search-space for brute force, but also to greater potential for fragmentation. The offset added to the mmap_base address, which provides the basis for the majority of the mappings for a process, is set once on process exec in arch_pick_mmap_layout() and is done via hard-coded per-arch values, which reflect, hopefully, the best compromise for all systems. The trade-off between increased entropy in the offset value generation and the corresponding increased variability in address space fragmentation is not absolute, however, and some platforms may tolerate higher amounts of entropy. This patch introduces both new Kconfig values and a sysctl interface which may be used to change the amount of entropy used for offset generation on a system. The direct motivation for this change was in response to the libstagefright vulnerabilities that affected Android, specifically to information provided by Google's project zero at: http://googleprojectzero.blogspot.com/2015/09/stagefrightened.html The attack presented therein, by Google's project zero, specifically targeted the limited randomness used to generate the offset added to the mmap_base address in order to craft a brute-force-based attack. Concretely, the attack was against the mediaserver process, which was limited to respawning every 5 seconds, on an arm device. The hard-coded 8 bits used resulted in an average expected success rate of defeating the mmap ASLR after just over 10 minutes (128 tries at 5 seconds a piece). With this patch, and an accompanying increase in the entropy value to 16 bits, the same attack would take an average expected time of over 45 hours (32768 tries), which makes it both less feasible and more likely to be noticed. The introduced Kconfig and sysctl options are limited by per-arch minimum and maximum values, the minimum of which was chosen to match the current hard-coded value and the maximum of which was chosen so as to give the greatest flexibility without generating an invalid mmap_base address, generally a 3-4 bits less than the number of bits in the user-space accessible virtual address space. When decided whether or not to change the default value, a system developer should consider that mmap_base address could be placed anywhere up to 2^(value) bits away from the non-randomized location, which would introduce variable-sized areas above and below the mmap_base address such that the maximum vm_area_struct size may be reduced, preventing very large allocations. This patch (of 4): ASLR only uses as few as 8 bits to generate the random offset for the mmap base address on 32 bit architectures. This value was chosen to prevent a poorly chosen value from dividing the address space in such a way as to prevent large allocations. This may not be an issue on all platforms. Allow the specification of a minimum number of bits so that platforms desiring greater ASLR protection may determine where to place the trade-off. Signed-off-by: Daniel Cashman <dcashman@google.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Kees Cook <keescook@chromium.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Don Zickus <dzickus@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Rientjes <rientjes@google.com> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Nick Kralevich <nnk@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Borislav Petkov <bp@suse.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kexec: split kexec_load syscall from kexec core codeDave Young
There are two kexec load syscalls, kexec_load another and kexec_file_load. kexec_file_load has been splited as kernel/kexec_file.c. In this patch I split kexec_load syscall code to kernel/kexec.c. And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and use kexec_file_load only, or vice verse. The original requirement is from Ted Ts'o, he want kexec kernel signature being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use kexec_load syscall can bypass the checking. Vivek Goyal proposed to create a common kconfig option so user can compile in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects KEXEC_CORE so that old config files still work. Because there's general code need CONFIG_KEXEC_CORE, so I updated all the architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects KEXEC_CORE in arch Kconfig. Also updated general kernel code with to kexec_load syscall. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Dave Young <dyoung@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Josh Boyer <jwboyer@fedoraproject.org> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "In this one: - d_move fixes (Eric Biederman) - UFS fixes (me; locking is mostly sane now, a bunch of bugs in error handling ought to be fixed) - switch of sb_writers to percpu rwsem (Oleg Nesterov) - superblock scalability (Josef Bacik and Dave Chinner) - swapon(2) race fix (Hugh Dickins)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (65 commits) vfs: Test for and handle paths that are unreachable from their mnt_root dcache: Reduce the scope of i_lock in d_splice_alias dcache: Handle escaped paths in prepend_path mm: fix potential data race in SyS_swapon inode: don't softlockup when evicting inodes inode: rename i_wb_list to i_io_list sync: serialise per-superblock sync operations inode: convert inode_sb_list_lock to per-sb inode: add hlist_fake to avoid the inode hash lock in evict writeback: plug writeback at a high level change sb_writers to use percpu_rw_semaphore shift percpu_counter_destroy() into destroy_super_work() percpu-rwsem: kill CONFIG_PERCPU_RWSEM percpu-rwsem: introduce percpu_rwsem_release() and percpu_rwsem_acquire() percpu-rwsem: introduce percpu_down_read_trylock() document rwsem_release() in sb_wait_write() fix the broken lockdep logic in __sb_start_write() introduce __sb_writers_{acquired,release}() helpers ufs_inode_get{frag,block}(): get rid of 'phys' argument ufs_getfrag_block(): tidy up a bit ...
2015-08-15percpu-rwsem: kill CONFIG_PERCPU_RWSEMOleg Nesterov
Remove CONFIG_PERCPU_RWSEM, the next patch adds the unconditional user of percpu_rw_semaphore. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2015-08-03locking/static_keys: Add selftestPeter Zijlstra
Add a little selftest that validates all combinations. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-18x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it ↵Ingo Molnar
on x86 Don't burden architectures without dynamic task_struct sizing with the overhead of dynamic sizing. Also optimize the x86 code a bit by caching task_struct_size. Acked-and-Tested-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1437128892-9831-3-git-send-email-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-25clone: support passing tls argument via C rather than pt_regs magicJosh Triplett
clone has some of the quirkiest syscall handling in the kernel, with a pile of special cases, historical curiosities, and architecture-specific calling conventions. In particular, clone with CLONE_SETTLS accepts a parameter "tls" that the C entry point completely ignores and some assembly entry points overwrite; instead, the low-level arch-specific code pulls the tls parameter out of the arch-specific register captured as part of pt_regs on entry to the kernel. That's a massive hack, and it makes the arch-specific code only work when called via the specific existing syscall entry points; because of this hack, any new clone-like system call would have to accept an identical tls argument in exactly the same arch-specific position, rather than providing a unified system call entry point across architectures. The first patch allows architectures to handle the tls argument via normal C parameter passing, if they opt in by selecting HAVE_COPY_THREAD_TLS. The second patch makes 32-bit and 64-bit x86 opt into this. These two patches came out of the clone4 series, which isn't ready for this merge window, but these first two cleanup patches were entirely uncontroversial and have acks. I'd like to go ahead and submit these two so that other architectures can begin building on top of this and opting into HAVE_COPY_THREAD_TLS. However, I'm also happy to wait and send these through the next merge window (along with v3 of clone4) if anyone would prefer that. This patch (of 2): clone with CLONE_SETTLS accepts an argument to set the thread-local storage area for the new thread. sys_clone declares an int argument tls_val in the appropriate point in the argument list (based on the various CLONE_BACKWARDS variants), but doesn't actually use or pass along that argument. Instead, sys_clone calls do_fork, which calls copy_process, which calls the arch-specific copy_thread, and copy_thread pulls the corresponding syscall argument out of the pt_regs captured at kernel entry (knowing what argument of clone that architecture passes tls in). Apart from being awful and inscrutable, that also only works because only one code path into copy_thread can pass the CLONE_SETTLS flag, and that code path comes from sys_clone with its architecture-specific argument-passing order. This prevents introducing a new version of the clone system call without propagating the same architecture-specific position of the tls argument. However, there's no reason to pull the argument out of pt_regs when sys_clone could just pass it down via C function call arguments. Introduce a new CONFIG_HAVE_COPY_THREAD_TLS for architectures to opt into, and a new copy_thread_tls that accepts the tls parameter as an additional unsigned long (syscall-argument-sized) argument. Change sys_clone's tls argument to an unsigned long (which does not change the ABI), and pass that down to copy_thread_tls. Architectures that don't opt into copy_thread_tls will continue to ignore the C argument to sys_clone in favor of the pt_regs captured at kernel entry, and thus will be unable to introduce new versions of the clone syscall. Patch co-authored by Josh Triplett and Thiago Macieira. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thiago Macieira <thiago.macieira@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-16Merge tag 'powerpc-4.1-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux Pull powerpc updates from Michael Ellerman: - Numerous minor fixes, cleanups etc. - More EEH work from Gavin to remove its dependency on device_nodes. - Memory hotplug implemented entirely in the kernel from Nathan Fontenot. - Removal of redundant CONFIG_PPC_OF by Kevin Hao. - Rewrite of VPHN parsing logic & tests from Greg Kurz. - A fix from Nish Aravamudan to reduce memory usage by clamping nodes_possible_map. - Support for pstore on powernv from Hari Bathini. - Removal of old powerpc specific byte swap routines by David Gibson. - Fix from Vasant Hegde to prevent the flash driver telling you it was flashing your firmware when it wasn't. - Patch from Ben Herrenschmidt to add an OPAL heartbeat driver. - Fix for an oops causing get/put_cpu_var() imbalance in perf by Jan Stancek. - Some fixes for migration from Tyrel Datwyler. - A new syscall to switch the cpu endian by Michael Ellerman. - Large series from Wei Yang to implement SRIOV, reviewed and acked by Bjorn. - A fix for the OPAL sensor driver from Cédric Le Goater. - Fixes to get STRICT_MM_TYPECHECKS building again by Michael Ellerman. - Large series from Daniel Axtens to make our PCI hooks per PHB rather than per machine. - Small patch from Sam Bobroff to explicitly abort non-suspended transactions on syscalls, plus a test to exercise it. - Numerous reworks and fixes for the 24x7 PMU from Sukadev Bhattiprolu. - Small patch to enable the hard lockup detector from Anton Blanchard. - Fix from Dave Olson for missing L2 cache information on some CPUs. - Some fixes from Michael Ellerman to get Cell machines booting again. - Freescale updates from Scott: Highlights include BMan device tree nodes, an MSI erratum workaround, a couple minor performance improvements, config updates, and misc fixes/cleanup. * tag 'powerpc-4.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (196 commits) powerpc/powermac: Fix build error seen with powermac smp builds powerpc/pseries: Fix compile of memory hotplug without CONFIG_MEMORY_HOTREMOVE powerpc: Remove PPC32 code from pseries specific find_and_init_phbs() powerpc/cell: Fix iommu breakage caused by controller_ops change powerpc/eeh: Fix crash in eeh_add_device_early() on Cell powerpc/perf: Cap 64bit userspace backtraces to PERF_MAX_STACK_DEPTH powerpc/perf/hv-24x7: Fail 24x7 initcall if create_events_from_catalog() fails powerpc/pseries: Correct memory hotplug locking powerpc: Fix missing L2 cache size in /sys/devices/system/cpu powerpc: Add ppc64 hard lockup detector support oprofile: Disable oprofile NMI timer on ppc64 powerpc/perf/hv-24x7: Add missing put_cpu_var() powerpc/perf/hv-24x7: Break up single_24x7_request powerpc/perf/hv-24x7: Define update_event_count() powerpc/perf/hv-24x7: Whitespace cleanup powerpc/perf/hv-24x7: Define add_event_to_24x7_request() powerpc/perf/hv-24x7: Rename hv_24x7_event_update powerpc/perf/hv-24x7: Move debug prints to separate function powerpc/perf/hv-24x7: Drop event_24x7_request() powerpc/perf/hv-24x7: Use pr_devel() to log message ... Conflicts: tools/testing/selftests/powerpc/Makefile tools/testing/selftests/powerpc/tm/Makefile
2015-04-14mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZEKees Cook
The arch_randomize_brk() function is used on several architectures, even those that don't support ET_DYN ASLR. To avoid bulky extern/#define tricks, consolidate the support under CONFIG_ARCH_HAS_ELF_RANDOMIZE for the architectures that support it, while still handling CONFIG_COMPAT_BRK. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Russell King <linux@arm.linux.org.uk> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: "David A. Long" <dave.long@linaro.org> Cc: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Arun Chandran <achandran@mvista.com> Cc: Yann Droneaud <ydroneaud@opteya.com> Cc: Min-Hua Chen <orca.chen@gmail.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Vineeth Vijayan <vvijayan@mvista.com> Cc: Jeff Bailey <jeffbailey@google.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Behan Webster <behanw@converseincode.com> Cc: Ismael Ripoll <iripoll@upv.es> Cc: Jan-Simon Mller <dl9pf@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14mm: expose arch_mmap_rnd when availableKees Cook
When an architecture fully supports randomizing the ELF load location, a per-arch mmap_rnd() function is used to find a randomized mmap base. In preparation for randomizing the location of ET_DYN binaries separately from mmap, this renames and exports these functions as arch_mmap_rnd(). Additionally introduces CONFIG_ARCH_HAS_ELF_RANDOMIZE for describing this feature on architectures that support it (which is a superset of ARCH_BINFMT_ELF_RANDOMIZE_PIE, since s390 already supports a separated ET_DYN ASLR from mmap ASLR without the ARCH_BINFMT_ELF_RANDOMIZE_PIE logic). Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Russell King <linux@arm.linux.org.uk> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: "David A. Long" <dave.long@linaro.org> Cc: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Arun Chandran <achandran@mvista.com> Cc: Yann Droneaud <ydroneaud@opteya.com> Cc: Min-Hua Chen <orca.chen@gmail.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Vineeth Vijayan <vvijayan@mvista.com> Cc: Jeff Bailey <jeffbailey@google.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Behan Webster <behanw@converseincode.com> Cc: Ismael Ripoll <iripoll@upv.es> Cc: Jan-Simon Mller <dl9pf@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14lib/ioremap.c: add huge I/O map capability interfacesToshi Kani
Add ioremap_pud_enabled() and ioremap_pmd_enabled(), which return 1 when I/O mappings with pud/pmd are enabled on the kernel. ioremap_huge_init() calls arch_ioremap_pud_supported() and arch_ioremap_pmd_supported() to initialize the capabilities at boot-time. A new kernel option "nohugeiomap" is also added, so that user can disable the huge I/O map capabilities when necessary. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Robert Elliott <Elliott@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14mm: define default PGTABLE_LEVELS to twoKirill A. Shutemov
By this time all architectures which support more than two page table levels should be covered. This patch add default definiton of PGTABLE_LEVELS equal 2. We also add assert to detect inconsistence between CONFIG_PGTABLE_LEVELS and __PAGETABLE_PMD_FOLDED/__PAGETABLE_PUD_FOLDED. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: David Howells <dhowells@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-11oprofile: Disable oprofile NMI timer on ppc64Anton Blanchard
We want to enable the hard lockup detector on ppc64, but right now that enables the oprofile NMI timer too. We'd prefer not to enable the oprofile NMI timer, it adds another element to our PMU testing and it requires us to increase our exported symbols (eg cpu_khz). Modify the config entry for OPROFILE_NMI_TIMER to disable it on PPC64. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Robert Richter <rric@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-09-03seccomp: Document two-phase seccomp and arch-provided seccomp_dataAndy Lutomirski
The description of how archs should implement seccomp filters was still strictly correct, but it failed to describe the newly available optimizations. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Kees Cook <keescook@chromium.org>
2014-07-18seccomp: add "seccomp" syscallKees Cook
This adds the new "seccomp" syscall with both an "operation" and "flags" parameter for future expansion. The third argument is a pointer value, used with the SECCOMP_SET_MODE_FILTER operation. Currently, flags must be 0. This is functionally equivalent to prctl(PR_SET_SECCOMP, ...). In addition to the TSYNC flag later in this patch series, there is a non-zero chance that this syscall could be used for configuring a fixed argument area for seccomp-tracer-aware processes to pass syscall arguments in the future. Hence, the use of "seccomp" not simply "seccomp_add_filter" for this syscall. Additionally, this syscall uses operation, flags, and user pointer for arguments because strictly passing arguments via a user pointer would mean seccomp itself would be unable to trivially filter the seccomp syscall itself. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Andy Lutomirski <luto@amacapital.net>
2014-03-18uprobes: Kconfig dependency fixDavid A. Long
Suggested change from Oleg Nesterov. Fixes incomplete dependencies for uprobes feature. Signed-off-by: David A. Long <dave.long@linaro.org> Acked-by: Oleg Nesterov <oleg@redhat.com>
2013-12-20stackprotector: Introduce CONFIG_CC_STACKPROTECTOR_STRONGKees Cook
This changes the stack protector config option into a choice of "None", "Regular", and "Strong": CONFIG_CC_STACKPROTECTOR_NONE CONFIG_CC_STACKPROTECTOR_REGULAR CONFIG_CC_STACKPROTECTOR_STRONG "Regular" means the old CONFIG_CC_STACKPROTECTOR=y option. "Strong" is a new mode introduced by this patch. With "Strong" the kernel is built with -fstack-protector-strong (available in gcc 4.9 and later). This option increases the coverage of the stack protector without the heavy performance hit of -fstack-protector-all. For reference, the stack protector options available in gcc are: -fstack-protector-all: Adds the stack-canary saving prefix and stack-canary checking suffix to _all_ function entry and exit. Results in substantial use of stack space for saving the canary for deep stack users (e.g. historically xfs), and measurable (though shockingly still low) performance hit due to all the saving/checking. Really not suitable for sane systems, and was entirely removed as an option from the kernel many years ago. -fstack-protector: Adds the canary save/check to functions that define an 8 (--param=ssp-buffer-size=N, N=8 by default) or more byte local char array. Traditionally, stack overflows happened with string-based manipulations, so this was a way to find those functions. Very few total functions actually get the canary; no measurable performance or size overhead. -fstack-protector-strong Adds the canary for a wider set of functions, since it's not just those with strings that have ultimately been vulnerable to stack-busting. With this superset, more functions end up with a canary, but it still remains small compared to all functions with only a small change in performance. Based on the original design document, a function gets the canary when it contains any of: - local variable's address used as part of the right hand side of an assignment or function argument - local variable is an array (or union containing an array), regardless of array type or length - uses register local variables https://docs.google.com/a/google.com/document/d/1xXBH6rRZue4f296vGt9YQcuLVQHeE516stHwt8M9xyU Find below a comparison of "size" and "objdump" output when built with gcc-4.9 in three configurations: - defconfig 11430641 kernel text size 36110 function bodies - defconfig + CONFIG_CC_STACKPROTECTOR_REGULAR 11468490 kernel text size (+0.33%) 1015 of 36110 functions are stack-protected (2.81%) - defconfig + CONFIG_CC_STACKPROTECTOR_STRONG via this patch 11692790 kernel text size (+2.24%) 7401 of 36110 functions are stack-protected (20.5%) With -strong, ARM's compressed boot code now triggers stack protection, so a static guard was added. Since this is only used during decompression and was never used before, the exposure here is very small. Once it switches to the full kernel, the stack guard is back to normal. Chrome OS has been using -fstack-protector-strong for its kernel builds for the last 8 months with no problems. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Michal Marek <mmarek@suse.cz> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: James Hogan <james.hogan@imgtec.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@linux-mips.org Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/1387481759-14535-3-git-send-email-keescook@chromium.org [ Improved the changelog and descriptions some more. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-12-20stackprotector: Unify the HAVE_CC_STACKPROTECTOR logic between architecturesKees Cook
Instead of duplicating the CC_STACKPROTECTOR Kconfig and Makefile logic in each architecture, switch to using HAVE_CC_STACKPROTECTOR and keep everything in one place. This retains the x86-specific bug verification scripts. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Michal Marek <mmarek@suse.cz> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: James Hogan <james.hogan@imgtec.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@linux-mips.org Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/1387481759-14535-2-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-15kernel: remove CONFIG_USE_GENERIC_SMP_HELPERSChristoph Hellwig
We've switched over every architecture that supports SMP to it, so remove the new useless config variable. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-12Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer changes from Ingo Molnar: "Main changes in this cycle were: - Updated full dynticks support. - Event stream support for architected (ARM) timers. - ARM clocksource driver updates. - Move arm64 to using the generic sched_clock framework & resulting cleanup in the generic sched_clock code. - Misc fixes and cleanups" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits) x86/time: Honor ACPI FADT flag indicating absence of a CMOS RTC clocksource: sun4i: remove IRQF_DISABLED clocksource: sun4i: Report the minimum tick that we can program clocksource: sun4i: Select CLKSRC_MMIO clocksource: Provide timekeeping for efm32 SoCs clocksource: em_sti: convert to clk_prepare/unprepare time: Fix signedness bug in sysfs_get_uname() and its callers timekeeping: Fix some trivial typos in comments alarmtimer: return EINVAL instead of ENOTSUPP if rtcdev doesn't exist clocksource: arch_timer: Do not register arch_sys_counter twice timer stats: Add a 'Collection: active/inactive' line to timer usage statistics sched_clock: Remove sched_clock_func() hook arch_timer: Move to generic sched_clock framework clocksource: tcb_clksrc: Remove IRQF_DISABLED clocksource: tcb_clksrc: Improve driver robustness clocksource: tcb_clksrc: Replace clk_enable/disable with clk_prepare_enable/disable_unprepare clocksource: arm_arch_timer: Use clocksource for suspend timekeeping clocksource: dw_apb_timer_of: Mark a few more functions as __init clocksource: Put nodes passed to CLOCKSOURCE_OF_DECLARE callbacks centrally arm: zynq: Enable arm_global_timer ...
2013-10-01irq: Optimize softirq stack selection in irq exitFrederic Weisbecker
If irq_exit() is called on the arch's specified irq stack, it should be safe to run softirqs inline under that same irq stack as it is near empty by the time we call irq_exit(). For example if we use the same stack for both hard and soft irqs here, the worst case scenario is: hardirq -> softirq -> hardirq. But then the softirq supersedes the first hardirq as the stack user since irq_exit() is called in a mostly empty stack. So the stack merge in this case looks acceptable. Stack overrun still have a chance to happen if hardirqs have more opportunities to nest, but then it's another problem to solve. So lets adapt the irq exit's softirq stack on top of a new Kconfig symbol that can be defined when irq_exit() runs on the irq stack. That way we can spare some stack switch on irq processing and all the cache issues that come along. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@au1.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@au1.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org>
2013-09-30vtime: Add HAVE_VIRT_CPU_ACCOUNTING_GEN KconfigKevin Hilman
With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit. In order to use that feature, arch code should be audited to ensure there are no races in concurrent read/write of cputime_t. For example, reading/writing 64-bit cputime_t on some 32-bit arches may require multiple accesses for low and high value parts, so proper locking is needed to protect against concurrent accesses. Therefore, add CONFIG_HAVE_VIRT_CPU_ACCOUNTING_GEN which arches can enable after they've been audited for potential races. This option is automatically enabled on 64-bit platforms. Feature requested by Frederic Weisbecker. Signed-off-by: Kevin Hilman <khilman@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Arm Linux <linux-arm-kernel@lists.infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2013-09-28mutex: replace CONFIG_HAVE_ARCH_MUTEX_CPU_RELAX with simple ifdefHeiko Carstens
Linus suggested to replace #ifndef CONFIG_HAVE_ARCH_MUTEX_CPU_RELAX #define arch_mutex_cpu_relax() cpu_relax() #endif with just a simple #ifndef arch_mutex_cpu_relax # define arch_mutex_cpu_relax() cpu_relax() #endif to get rid of CONFIG_HAVE_CPU_RELAX_SIMPLE. So architectures can simply define arch_mutex_cpu_relax if they want an architecture specific function instead of having to add a select statement in their Kconfig in addition. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2013-08-13microblaze: fix clone syscallMichal Simek
Fix inadvertent breakage in the clone syscall ABI for Microblaze that was introduced in commit f3268edbe6fe ("microblaze: switch to generic fork/vfork/clone"). The Microblaze syscall ABI for clone takes the parent tid address in the 4th argument; the third argument slot is used for the stack size. The incorrectly-used CLONE_BACKWARDS type assigned parent tid to the 3rd slot. This commit restores the original ABI so that existing userspace libc code will work correctly. All kernel versions from v3.8-rc1 were affected. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: soft-dirty bits for user memory changes trackingPavel Emelyanov
The soft-dirty is a bit on a PTE which helps to track which pages a task writes to. In order to do this tracking one should 1. Clear soft-dirty bits from PTEs ("echo 4 > /proc/PID/clear_refs) 2. Wait some time. 3. Read soft-dirty bits (55'th in /proc/PID/pagemap2 entries) To do this tracking, the writable bit is cleared from PTEs when the soft-dirty bit is. Thus, after this, when the task tries to modify a page at some virtual address the #PF occurs and the kernel sets the soft-dirty bit on the respective PTE. Note, that although all the task's address space is marked as r/o after the soft-dirty bits clear, the #PF-s that occur after that are processed fast. This is so, since the pages are still mapped to physical memory, and thus all the kernel does is finds this fact out and puts back writable, dirty and soft-dirty bits on the PTE. Another thing to note, is that when mremap moves PTEs they are marked with soft-dirty as well, since from the user perspective mremap modifies the virtual memory at mremap's new address. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-15Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core fixes from Thomas Gleixner: - Two fixlets for the fallout of the generic idle task conversion - Documentation update * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rcu/idle: Wrap cpu-idle poll mode within rcu_idle_enter/exit idle: Fix hlt/nohlt command-line handling in new generic idle kthread: Document ways of reducing OS jitter due to per-CPU kthreads
2013-05-05Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull mudule updates from Rusty Russell: "We get rid of the general module prefix confusion with a binary config option, fix a remove/insert race which Never Happens, and (my favorite) handle the case when we have too many modules for a single commandline. Seriously, the kernel is full, please go away!" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: modpost: fix unwanted VMLINUX_SYMBOL_STR expansion X.509: Support parse long form of length octets in Authority Key Identifier module: don't unlink the module until we've removed all exposure. kernel: kallsyms: memory override issue, need check destination buffer length MODSIGN: do not send garbage to stderr when enabling modules signature modpost: handle huge numbers of modules. modpost: add -T option to read module names from file/stdin. modpost: minor cleanup. genksyms: pass symbol-prefix instead of arch module: fix symbol versioning with symbol prefixes CONFIG_SYMBOL_PREFIX: cleanup.
2013-05-05idle: Fix hlt/nohlt command-line handling in new generic idleKevin Hilman
commit d1669912 (idle: Implement generic idle function) added a new generic idle along with support for hlt/nohlt command line options to override default idle loop behavior. However, the command-line processing is never compiled. The command-line handling is wrapped by CONFIG_GENERIC_IDLE_POLL_SETUP and arches that use this feature select it in their Kconfigs. However, no Kconfig definition was created for this option, so it is never enabled, and therefore command-line override of the idle-loop behavior is broken after migrating to the generic idle loop. To fix, add a Kconfig definition for GENERIC_IDLE_POLL_SETUP. Tested on ARM (OMAP4/Panda) which enables the command-line overrides by default. Signed-off-by: Kevin Hilman <khilman@linaro.org> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linaro-kernel@lists.linaro.org Link: http://lkml.kernel.org/r/1366849153-25564-1-git-send-email-khilman@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-05-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull compat cleanup from Al Viro: "Mostly about syscall wrappers this time; there will be another pile with patches in the same general area from various people, but I'd rather push those after both that and vfs.git pile are in." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: syscalls.h: slightly reduce the jungles of macros get rid of union semop in sys_semctl(2) arguments make do_mremap() static sparc: no need to sign-extend in sync_file_range() wrapper ppc compat wrappers for add_key(2) and request_key(2) are pointless x86: trim sys_ia32.h x86: sys32_kill and sys32_mprotect are pointless get rid of compat_sys_semctl() and friends in case of ARCH_WANT_OLD_COMPAT_IPC merge compat sys_ipc instances consolidate compat lookup_dcookie() convert vmsplice to COMPAT_SYSCALL_DEFINE switch getrusage() to COMPAT_SYSCALL_DEFINE switch epoll_pwait to COMPAT_SYSCALL_DEFINE convert sendfile{,64} to COMPAT_SYSCALL_DEFINE switch signalfd{,4}() to COMPAT_SYSCALL_DEFINE make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect make HAVE_SYSCALL_WRAPPERS unconditional consolidate cond_syscall and SYSCALL_ALIAS declarations teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long get rid of duplicate logics in __SC_....[1-6] definitions
2013-03-15CONFIG_SYMBOL_PREFIX: cleanup.Rusty Russell
We have CONFIG_SYMBOL_PREFIX, which three archs define to the string "_". But Al Viro broke this in "consolidate cond_syscall and SYSCALL_ALIAS declarations" (in linux-next), and he's not the first to do so. Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to prefix it so something. So various places define helpers which are defined to nothing if CONFIG_SYMBOL_PREFIX isn't set: 1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX. 2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym) 3) include/linux/export.h defines MODULE_SYMBOL_PREFIX. 4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7) 5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym) 6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX 7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version for pasting. (arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too). Let's solve this properly: 1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX. 2) Make linux/export.h usable from asm. 3) Define VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR(). 4) Make everyone use them. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: James Hogan <james.hogan@imgtec.com> Tested-by: James Hogan <james.hogan@imgtec.com> (metag)
2013-03-12Select VIRT_TO_BUS directly where neededStephen Rothwell
In commit 887cbce0adea ("arch Kconfig: centralise ARCH_NO_VIRT_TO_BUS") I introduced the config sybmol HAVE_VIRT_TO_BUS and selected that where needed. I am not sure what I was thinking. Instead, just directly select VIRT_TO_BUS where it is needed. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-03make HAVE_SYSCALL_WRAPPERS unconditionalAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-03-03Merge tag 'metag-v3.9-rc1-v4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag Pull new ImgTec Meta architecture from James Hogan: "This adds core architecture support for Imagination's Meta processor cores, followed by some later miscellaneous arch/metag cleanups and fixes which I kept separate to ease review: - Support for basic Meta 1 (ATP) and Meta 2 (HTP) core architecture - A few fixes all over, particularly for symbol prefixes - A few privilege protection fixes - Several cleanups (setup.c includes, split out a lot of metag_ksyms.c) - Fix some missing exports - Convert hugetlb to use vm_unmapped_area() - Copy device tree to non-init memory - Provide dma_get_sgtable()" * tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: (61 commits) metag: Provide dma_get_sgtable() metag: prom.h: remove declaration of metag_dt_memblock_reserve() metag: copy devicetree to non-init memory metag: cleanup metag_ksyms.c includes metag: move mm/init.c exports out of metag_ksyms.c metag: move usercopy.c exports out of metag_ksyms.c metag: move setup.c exports out of metag_ksyms.c metag: move kick.c exports out of metag_ksyms.c metag: move traps.c exports out of metag_ksyms.c metag: move irq enable out of irqflags.h on SMP genksyms: fix metag symbol prefix on crc symbols metag: hugetlb: convert to vm_unmapped_area() metag: export clear_page and copy_page metag: export metag_code_cache_flush_all metag: protect more non-MMU memory regions metag: make TXPRIVEXT bits explicit metag: kernel/setup.c: sort includes perf: Enable building perf tools for Meta metag: add boot time LNKGET/LNKSET check metag: add __init to metag_cache_probe() ...
2013-03-02Add HAVE_64BIT_ALIGNED_ACCESSJames Hogan
On 64 bit architectures with no efficient unaligned access, padding and explicit alignment must be added in various places to prevent unaligned 64bit accesses (such as taskstats and trace ring buffer). However this also needs to apply to 32 bit architectures with 64 bit accesses requiring alignment such as metag. This is solved by adding a new Kconfig symbol HAVE_64BIT_ALIGNED_ACCESS which defaults to 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS, and can be explicitly selected by METAG and any other relevant architectures. This can be used in various places to determine whether 64bit alignment is required. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Eric Paris <eparis@redhat.com> Cc: Will Drewry <wad@chromium.org>
2013-02-27arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUSStephen Rothwell
Change it to CONFIG_HAVE_VIRT_TO_BUS and set it in all architecures that already provide virt_to_bus(). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: H Hartley Sweeten <hartleys@visionengravers.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull signal handling cleanups from Al Viro: "This is the first pile; another one will come a bit later and will contain SYSCALL_DEFINE-related patches. - a bunch of signal-related syscalls (both native and compat) unified. - a bunch of compat syscalls switched to COMPAT_SYSCALL_DEFINE (fixing several potential problems with missing argument validation, while we are at it) - a lot of now-pointless wrappers killed - a couple of architectures (cris and hexagon) forgot to save altstack settings into sigframe, even though they used the (uninitialized) values in sigreturn; fixed. - microblaze fixes for delivery of multiple signals arriving at once - saner set of helpers for signal delivery introduced, several architectures switched to using those." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (143 commits) x86: convert to ksignal sparc: convert to ksignal arm: switch to struct ksignal * passing alpha: pass k_sigaction and siginfo_t using ksignal pointer burying unused conditionals make do_sigaltstack() static arm64: switch to generic old sigaction() (compat-only) arm64: switch to generic compat rt_sigaction() arm64: switch compat to generic old sigsuspend arm64: switch to generic compat rt_sigqueueinfo() arm64: switch to generic compat rt_sigpending() arm64: switch to generic compat rt_sigprocmask() arm64: switch to generic sigaltstack sparc: switch to generic old sigsuspend sparc: COMPAT_SYSCALL_DEFINE does all sign-extension as well as SYSCALL_DEFINE sparc: kill sign-extending wrappers for native syscalls kill sparc32_open() sparc: switch to use of generic old sigaction sparc: switch sys_compat_rt_sigaction() to COMPAT_SYSCALL_DEFINE mips: switch to generic sys_fork() and sys_clone() ...
2013-02-14burying unused conditionalsAl Viro
__ARCH_WANT_SYS_RT_SIGACTION, __ARCH_WANT_SYS_RT_SIGSUSPEND, __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND, __ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL - not used anymore CONFIG_GENERIC_{SIGALTSTACK,COMPAT_RT_SIG{ACTION,QUEUEINFO,PENDING,PROCMASK}} - can be assumed always set.
2013-02-03generic sys_sigaction() and compat_sys_sigaction()Al Viro
conditional on OLD_SIGACTION/COMPAT_OLD_SIGACTION Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-03generic sys_compat_rt_sigaction()Al Viro
Again, protected by a temporary config symbol (GENERIC_COMPAT_RT_SIGACTION); will be gone by the end of series. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-03old sigsuspend variants in kernel/signal.cAl Viro
conditional on OLD_SIGSUSPEND/OLD_SIGSUSPEND3, depending on which variety of that fossil is needed. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-03generic compat_sys_rt_sigqueueinfo()Al Viro
conditional on GENERIC_COMPAT_RT_SIGQUEUEINFO; by the end of that series it will become the same thing as COMPAT and conditional will die out. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-03generic compat_sys_rt_sigpending()Al Viro
conditional on GENERIC_COMPAT_RT_SIGPENDING; by the end of that series it will become the same thing as COMPAT and conditional will die out. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-03generic compat_sys_rt_sigprocmask()Al Viro
conditional on GENERIC_COMPAT_RT_SIGPROCMASK; by the end of that series it will become the same thing as COMPAT and conditional will die out. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-03sanitize rt_sigaction() situation a bitAl Viro
Switch from __ARCH_WANT_SYS_RT_SIGACTION to opposite (!CONFIG_ODD_RT_SIGACTION); the only two architectures that need it are alpha and sparc. The reason for use of CONFIG_... instead of __ARCH_... is that it's needed only kernel-side and doing it that way avoids a mess with include order on many architectures. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-01-21kprobes/x86: Move ftrace-based kprobe code into kprobes-ftrace.cMasami Hiramatsu
Split ftrace-based kprobes code from kprobes, and introduce CONFIG_(HAVE_)KPROBES_ON_FTRACE Kconfig flags. For the cleanup reason, this also moves kprobe_ftrace check into skip_singlestep. Link: http://lkml.kernel.org/r/20120928081520.3560.25624.stgit@ltc138.sdl.hitachi.co.jp Cc: Ingo Molnar <mingo@elte.hu> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-12-20Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull signal handling cleanups from Al Viro: "sigaltstack infrastructure + conversion for x86, alpha and um, COMPAT_SYSCALL_DEFINE infrastructure. Note that there are several conflicts between "unify SS_ONSTACK/SS_DISABLE definitions" and UAPI patches in mainline; resolution is trivial - just remove definitions of SS_ONSTACK and SS_DISABLED from arch/*/uapi/asm/signal.h; they are all identical and include/uapi/linux/signal.h contains the unified variant." Fixed up conflicts as per Al. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: alpha: switch to generic sigaltstack new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those generic compat_sys_sigaltstack() introduce generic sys_sigaltstack(), switch x86 and um to it new helper: compat_user_stack_pointer() new helper: restore_altstack() unify SS_ONSTACK/SS_DISABLE definitions new helper: current_user_stack_pointer() missing user_stack_pointer() instances Bury the conditionals from kernel_thread/kernel_execve series COMPAT_SYSCALL_DEFINE: infrastructure
2012-12-19introduce generic sys_sigaltstack(), switch x86 and um to itAl Viro
Conditional on CONFIG_GENERIC_SIGALTSTACK; architectures that do not select it are completely unaffected Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19Bury the conditionals from kernel_thread/kernel_execve seriesAl Viro
All architectures have CONFIG_GENERIC_KERNEL_THREAD CONFIG_GENERIC_KERNEL_EXECVE __ARCH_WANT_SYS_EXECVE None of them have __ARCH_WANT_KERNEL_EXECVE and there are only two callers of kernel_execve() (which is a trivial wrapper for do_execve() now) left. Kill the conditionals and make both callers use do_execve(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19Merge tag 'byteswap-for-linus-20121219' of ↵Linus Torvalds
git://git.infradead.org/users/dwmw2/byteswap Pull preparatory gcc intrisics bswap patch from David Woodhouse: "This single patch is effectively a no-op for now. It enables architectures to opt in to using GCC's __builtin_bswapXX() intrinsics for byteswapping, and if we merge this now then the architecture maintainers can enable it for their arch during the next cycle without dependency issues. It's worth making it a par-arch opt-in, because although in *theory* the compiler should never do worse than hand-coded assembler (and of course it also ought to do a lot better on platforms like Atom and PowerPC which have load-and-swap or store-and-swap instructions), that isn't always the case. See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46453 for example." * tag 'byteswap-for-linus-20121219' of git://git.infradead.org/users/dwmw2/byteswap: byteorder: allow arch to opt to use GCC intrinsics for byteswapping
2012-12-17percpu_rw_semaphore: introduce CONFIG_PERCPU_RWSEMOleg Nesterov
Currently only block_dev and uprobes use percpu_rw_semaphore, add the config option selected by BLOCK || UPROBES. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Anton Arapov <anton@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>