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2015-08-10ARC: Make ARC bitops "safer" (add anti-optimization)Vineet Gupta
commit 80f420842ff42ad61f84584716d74ef635f13892 upstream. ARCompact/ARCv2 ISA provide that any instructions which deals with bitpos/count operand ASL, LSL, BSET, BCLR, BMSK .... will only consider lower 5 bits. i.e. auto-clamp the pos to 0-31. ARC Linux bitops exploited this fact by NOT explicitly masking out upper bits for @nr operand in general, saving a bunch of AND/BMSK instructions in generated code around bitops. While this micro-optimization has worked well over years it is NOT safe as shifting a number with a value, greater than native size is "undefined" per "C" spec. So as it turns outm EZChip ran into this eventually, in their massive muti-core SMP build with 64 cpus. There was a test_bit() inside a loop from 63 to 0 and gcc was weirdly optimizing away the first iteration (so it was really adhering to standard by implementing undefined behaviour vs. removing all the iterations which were phony i.e. (1 << [63..32]) | for i = 63 to 0 | X = ( 1 << i ) | if X == 0 | continue So fix the code to do the explicit masking at the expense of generating additional instructions. Fortunately, this can be mitigated to a large extent as gcc has SHIFT_COUNT_TRUNCATED which allows combiner to fold masking into shift operation itself. It is currently not enabled in ARC gcc backend, but could be done after a bit of testing. Fixes STAR 9000866918 ("unsafe "undefined behavior" code in kernel") Reported-by: Noam Camus <noamc@ezchip.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-10ARC: Reduce bitops lines of code using macrosVineet Gupta
commit 04e2eee4b02edcafce96c9c37b31b1a3318291a4 upstream. No semantical changes ! Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-10ARC: make sure instruction_pointer() returns unsigned valueAlexey Brodkin
commit f51e2f1911122879eefefa4c592dea8bf794b39c upstream. Currently instruction_pointer() returns pt_regs->ret and so return value is of type "long", which implicitly stands for "signed long". While that's perfectly fine when dealing with 32-bit values if return value of instruction_pointer() gets assigned to 64-bit variable sign extension may happen. And at least in one real use-case it happens already. In perf_prepare_sample() return value of perf_instruction_pointer() (which is an alias to instruction_pointer() in case of ARC) is assigned to (struct perf_sample_data)->ip (which type is "u64"). And what we see if instuction pointer points to user-space application that in case of ARC lays below 0x8000_0000 "ip" gets set properly with leading 32 zeros. But if instruction pointer points to kernel address space that starts from 0x8000_0000 then "ip" is set with 32 leadig "f"-s. I.e. id instruction_pointer() returns 0x8100_0000, "ip" will be assigned with 0xffff_ffff__8100_0000. Which is obviously wrong. In particular that issuse broke output of perf, because perf was unable to associate addresses like 0xffff_ffff__8100_0000 with anything from /proc/kallsyms. That's what we used to see: ----------->8---------- 6.27% ls [unknown] [k] 0xffffffff8046c5cc 2.96% ls libuClibc-0.9.34-git.so [.] memcpy 2.25% ls libuClibc-0.9.34-git.so [.] memset 1.66% ls [unknown] [k] 0xffffffff80666536 1.54% ls libuClibc-0.9.34-git.so [.] 0x000224d6 1.18% ls libuClibc-0.9.34-git.so [.] 0x00022472 ----------->8---------- With that change perf output looks much better now: ----------->8---------- 8.21% ls [kernel.kallsyms] [k] memset 3.52% ls libuClibc-0.9.34-git.so [.] memcpy 2.11% ls libuClibc-0.9.34-git.so [.] malloc 1.88% ls libuClibc-0.9.34-git.so [.] memset 1.64% ls [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore 1.41% ls [kernel.kallsyms] [k] __d_lookup_rcu ----------->8---------- Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: arc-linux-dev@synopsys.com Cc: linux-kernel@vger.kernel.org Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-10ARC: Override toplevel default -O2 with -O3Vineet Gupta
commit 97709069214eb75312c14946803b9da4d3814203 upstream. ARC kernels have historically been built with -O3, despite top level Makefile defaulting to -O2. This was facilitated by implicitly ordering of arch makefile include AFTER top level assigned -O2. An upstream fix to top level a1c48bb160f ("Makefile: Fix unrecognized cross-compiler command line options") changed the ordering, making ARC -O3 defunct. Fix that by NOT relying on any ordering whatsoever and use the proper arch override facility now present in kbuild (ARCH_*FLAGS) Depends-on: ("kbuild: Allow arch Makefiles to override {cpp,ld,c}flags") Suggested-by: Michal Marek <mmarek@suse.cz> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-21arc: fix use of uninitialized arc_pmuMax Filippov
commit 7002f77541f877a5590615ceb3da32b114f14b62 upstream. static arc_pmu in the arch/arc/kernel/perf_event.c is not initialized as it's shadowed by a local variable of the same name in the arc_pmu_device_probe. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Fixes: 03c94fcf954d "ARC: perf: make @arc_pmu static global" Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-21ARC: add compiler barrier to LLSC based cmpxchgVineet Gupta
commit d57f727264f1425a94689bafc7e99e502cb135b5 upstream. When auditing cmpxchg call sites, Chuck noted that gcc was optimizing away some of the desired LDs. | do { | new = old = *ipi_data_ptr; | new |= 1U << msg; | } while (cmpxchg(ipi_data_ptr, old, new) != old); was generating to below | 8015cef8: ld r2,[r4,0] <-- First LD | 8015cefc: bset r1,r2,r1 | | 8015cf00: llock r3,[r4] <-- atomic op | 8015cf04: brne r3,r2,8015cf10 | 8015cf08: scond r1,[r4] | 8015cf0c: bnz 8015cf00 | | 8015cf10: brne r3,r2,8015cf00 <-- Branch doesn't go to orig LD Although this was fixed by adding a ACCESS_ONCE in this call site, it seems safer (for now at least) to add compiler barrier to LLSC based cmpxchg Reported-by: Chuck Jordan <cjordan@synopsys.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-21ARC: add smp barriers around atomics per Documentation/atomic_ops.txtVineet Gupta
commit 2576c28e3f623ed401db7e6197241865328620ef upstream. - arch_spin_lock/unlock were lacking the ACQUIRE/RELEASE barriers Since ARCv2 only provides load/load, store/store and all/all, we need the full barrier - LLOCK/SCOND based atomics, bitops, cmpxchg, which return modified values were lacking the explicit smp barriers. - Non LLOCK/SCOND varaints don't need the explicit barriers since that is implicity provided by the spin locks used to implement the critical section (the spin lock barriers in turn are also fixed in this commit as explained above Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-11ARC: inline cache flush toggle helpersVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-05-11ARC: With earlycon in use, retire EARLY_PRINTKVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-05-10ARC: unbork !LLSC buildVineet Gupta
Fixes: f7d11e93ee97a locking,arch,arc: Fold atomic_ops Cc: <stable@kernel.vger.org> # 3.18 Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-24Merge tag 'arc-4.1-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc Pull ARC updates from Vineet Gupta: - perf fixes/improvements - misc cleanups * tag 'arc-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: ARC: perf: don't add code for impossible case ARC: perf: Rename DT binding to not confuse with power mgmt ARC: perf: add user space attribution in callchains ARC: perf: Add kernel callchain support ARC: perf: support cache hit/miss ratio ARC: perf: Add some comments/debug stuff ARC: perf: make @arc_pmu static global ARC: mem init spring cleaning - No functional changes ARC: Fix RTT boot printing ARC: fold __builtin_constant_p() into test_bit() ARC: rename unhandled exception handler ARC: cosmetic: Remove unused ECR bitfield masks ARC: Fix WRITE_BCR ARC: [nsimosci] Update defconfig arc: copy_thread(): rename 'arg' argument to 'kthread_arg'
2015-04-20ARC: perf: don't add code for impossible caseVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-20ARC: perf: Rename DT binding to not confuse with power mgmtVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-20ARC: perf: add user space attribution in callchainsVineet Gupta
The actual user space unwinding is more involved, so simply capture the user space PC Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-20ARC: perf: Add kernel callchain supportVineet Gupta
Signed-off-by: Mischa Jonker <mjonker@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-20ARC: perf: support cache hit/miss ratioVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-20ARC: perf: Add some comments/debug stuffVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-20ARC: perf: make @arc_pmu static globalVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-17arc: do not export symbols in troubleshoot.cDavidlohr Bueso
print_task_path_n_nm() is local to this file, its only user being show_regs(). Mark the function static and avoid the EXPORT_SYMBOL. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Vineet Gupta <vgupta@synoipsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15Merge branch 'exec_domain_rip_v2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc Pull exec domain removal from Richard Weinberger: "This series removes execution domain support from Linux. The idea behind exec domains was to support different ABIs. The feature was never complete nor stable. Let's rip it out and make the kernel signal handling code less complicated" * 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (27 commits) arm64: Removed unused variable sparc: Fix execution domain removal Remove rest of exec domains. arch: Remove exec_domain from remaining archs arc: Remove signal translation and exec_domain xtensa: Remove signal translation and exec_domain xtensa: Autogenerate offsets in struct thread_info x86: Remove signal translation and exec_domain unicore32: Remove signal translation and exec_domain um: Remove signal translation and exec_domain tile: Remove signal translation and exec_domain sparc: Remove signal translation and exec_domain sh: Remove signal translation and exec_domain s390: Remove signal translation and exec_domain mn10300: Remove signal translation and exec_domain microblaze: Remove signal translation and exec_domain m68k: Remove signal translation and exec_domain m32r: Remove signal translation and exec_domain m32r: Autogenerate offsets in struct thread_info frv: Remove signal translation and exec_domain ...
2015-04-14Merge branch 'for-linus-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs update from Al Viro: "Part one: - struct filename-related cleanups - saner iov_iter_init() replacements (and switching the syscalls to use of those) - ntfs switch to ->write_iter() (Anton) - aio cleanups and splitting iocb into common and async parts (Christoph) - assorted fixes (me, bfields, Andrew Elble) There's a lot more, including the completion of switchover to ->{read,write}_iter(), d_inode/d_backing_inode annotations, f_flags race fixes, etc, but that goes after #for-davem merge. David has pulled it, and once it's in I'll send the next vfs pull request" * 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (35 commits) sg_start_req(): use import_iovec() sg_start_req(): make sure that there's not too many elements in iovec blk_rq_map_user(): use import_single_range() sg_io(): use import_iovec() process_vm_access: switch to {compat_,}import_iovec() switch keyctl_instantiate_key_common() to iov_iter switch {compat_,}do_readv_writev() to {compat_,}import_iovec() aio_setup_vectored_rw(): switch to {compat_,}import_iovec() vmsplice_to_user(): switch to import_iovec() kill aio_setup_single_vector() aio: simplify arguments of aio_setup_..._rw() aio: lift iov_iter_init() into aio_setup_..._rw() lift iov_iter into {compat_,}do_readv_writev() NFS: fix BUG() crash in notify_change() with patch to chown_common() dcache: return -ESTALE not -EBUSY on distributed fs race NTFS: Version 2.1.32 - Update file write from aio_write to write_iter. VFS: Add iov_iter_fault_in_multipages_readable() drop bogus check in file_open_root() switch security_inode_getattr() to struct path * constify tomoyo_realpath_from_path() ...
2015-04-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree from Jiri Kosina: "Usual trivial tree updates. Nothing outstanding -- mostly printk() and comment fixes and unused identifier removals" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: goldfish: goldfish_tty_probe() is not using 'i' any more powerpc: Fix comment in smu.h qla2xxx: Fix printks in ql_log message lib: correct link to the original source for div64_u64 si2168, tda10071, m88ds3103: Fix firmware wording usb: storage: Fix printk in isd200_log_config() qla2xxx: Fix printk in qla25xx_setup_mode init/main: fix reset_device comment ipwireless: missing assignment goldfish: remove unreachable line of code coredump: Fix do_coredump() comment stacktrace.h: remove duplicate declaration task_struct smpboot.h: Remove unused function prototype treewide: Fix typo in printk messages treewide: Fix typo in printk messages mod_devicetable: fix comment for match_flags
2015-04-13ARC: mem init spring cleaning - No functional changesVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-13ARC: Fix RTT boot printingVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-13ARC: fold __builtin_constant_p() into test_bit()Vineet Gupta
This makes test_bit() more like its siblings *_bit() routines. Also add some comments about the constant @nr micro-optimization Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-13ARC: rename unhandled exception handlerVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-13ARC: cosmetic: Remove unused ECR bitfield masksVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-13ARC: Fix WRITE_BCRVineet Gupta
* There was obvious bit rot due to lack of use * Old naming was confusing since BCR are read only Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-13ARC: [nsimosci] Update defconfigMischa Jonker
Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
2015-04-12arc: Remove signal translation and exec_domainRichard Weinberger
As execution domain support is gone we can remove signal translation from the signal code and remove exec_domain from thread_info. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-11whack-a-mole: no need to set_fs(USER_DS) in {start,flush}_thread()Al Viro
flush_old_exec() has already done that. Back on 2011 a bunch of instances like that had been kicked out, but that hadn't taken care of then-out-of-tree architectures, obviously, and they served as reinfection vector... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-03-31arc: copy_thread(): rename 'arg' argument to 'kthread_arg'Alex Dowad
The 'arg' argument to copy_thread() is only ever used when forking a new kernel thread. Hence, rename it to 'kthread_arg' for clarity. Signed-off-by: Alex Dowad <alexinbeijing@gmail.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-03-26ARC: signal handling robustifyVineet Gupta
A malicious signal handler / restorer can DOS the system by fudging the user regs saved on stack, causing weird things such as sigreturn returning to user mode PC but cpu state still being kernel mode.... Ensure that in sigreturn path status32 always has U bit; any other bogosity (gargbage PC etc) will be taken care of by normal user mode exceptions mechanisms. Reproducer signal handler: void handle_sig(int signo, siginfo_t *info, void *context) { ucontext_t *uc = context; struct user_regs_struct *regs = &(uc->uc_mcontext.regs); regs->scratch.status32 = 0; } Before the fix, kernel would go off to weeds like below: --------->8----------- [ARCLinux]$ ./signal-test Path: /signal-test CPU: 0 PID: 61 Comm: signal-test Not tainted 4.0.0-rc5+ #65 task: 8f177880 ti: 5ffe6000 task.ti: 8f15c000 [ECR ]: 0x00220200 => Invalid Write @ 0x00000010 by insn @ 0x00010698 [EFA ]: 0x00000010 [BLINK ]: 0x2007c1ee [ERET ]: 0x10698 [STAT32]: 0x00000000 : <-------- BTA: 0x00010680 SP: 0x5ffe7e48 FP: 0x00000000 LPS: 0x20003c6c LPE: 0x20003c70 LPC: 0x00000000 ... --------->8----------- Reported-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: <stable@vger.kernel.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-03-26ARC: SA_SIGINFO ucontext regs off-by-oneVineet Gupta
The regfile provided to SA_SIGINFO signal handler as ucontext was off by one due to pt_regs gutter cleanups in 2013. Before handling signal, user pt_regs are copied onto user_regs_struct and copied back later. Both structs are binary compatible. This was all fine until commit 2fa919045b72 (ARC: pt_regs update #2) which removed the empty stack slot at top of pt_regs (corresponding to first pad) and made the corresponding fixup in struct user_regs_struct (the pad in there was moved out of @scratch - not removed altogether as it is part of ptrace ABI) struct user_regs_struct { + long pad; struct { - long pad; long bta, lp_start, lp_end,.... } scratch; ... } This meant that now user_regs_struct was off by 1 reg w.r.t pt_regs and signal code needs to user_regs_struct.scratch to reflect it as pt_regs, which is what this commit does. This problem was hidden for 2 years, because both save/restore, despite using wrong location, were using the same location. Only an interim inspection (reproducer below) exposed the issue. void handle_segv(int signo, siginfo_t *info, void *context) { ucontext_t *uc = context; struct user_regs_struct *regs = &(uc->uc_mcontext.regs); printf("regs %x %x\n", <=== prints 7 8 (vs. 8 9) regs->scratch.r8, regs->scratch.r9); } int main() { struct sigaction sa; sa.sa_sigaction = handle_segv; sa.sa_flags = SA_SIGINFO; sigemptyset(&sa.sa_mask); sigaction(SIGSEGV, &sa, NULL); asm volatile( "mov r7, 7 \n" "mov r8, 8 \n" "mov r9, 9 \n" "mov r10, 10 \n" :::"r7","r8","r9","r10"); *((unsigned int*)0x10) = 0; } Fixes: 2fa919045b72ec892e "ARC: pt_regs update #2: Remove unused gutter at start of pt_regs" CC: <stable@vger.kernel.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-03-06treewide: Fix typo in printk messagesMasanari Iida
This patch fix spelling typo in printk messages. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-02-27ARC: Fix thread_saved_pc()Vineet Gupta
The old implementation assumed that SP at the time of __switch_to() is right above pt_regs which is almost certainly not the case as there will be some stack build up between entry into kernel and leading up to __switch_to Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-27ARC: Fix KSTK_ESP()Vineet Gupta
/proc/<pid>/maps currently don't annotate stack vma with "[stack]" This is because KSTK_ESP ie expected to return usermode SP of tsk while currently it returns the kernel mode SP of a sleeping tsk. While the fix is trivial, we also need to adjust the ARC kernel stack unwinder to not use KSTK_SP and friends any more. Cc: <stable@vger.kernel.org> Reported-and-suggested-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-27ARC: perf: Enable generic software eventsVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-27ARC: Make arc_unwind_core accessible externallyVineet Gupta
The arc unwinder can also be used for perf callchains. Signed-off-by: Mischa Jonker <mjonker@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-18Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dmaLinus Torvalds
Pull dmaengine updates from Vinod Koul: "This update brings: - the big cleanup up by Maxime for device control and slave capabilities. This makes the API much cleaner. - new IMG MDC driver by Andrew - new Renesas R-Car Gen2 DMA Controller driver by Laurent along with bunch of fixes on rcar drivers - odd fixes and updates spread over driver" * 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (130 commits) dmaengine: pl330: add DMA_PAUSE feature dmaengine: pl330: improve pl330_tx_status() function dmaengine: rcar-dmac: Disable channel 0 when using IOMMU dmaengine: rcar-dmac: Work around descriptor mode IOMMU errata dmaengine: rcar-dmac: Allocate hardware descriptors with DMAC device dmaengine: rcar-dmac: Fix oops due to unintialized list in error ISR dmaengine: rcar-dmac: Fix spinlock issues in interrupt dmaenegine: edma: fix sparse warnings dmaengine: rcar-dmac: Fix uninitialized variable usage dmaengine: shdmac: extend PM methods dmaengine: shdmac: use SET_RUNTIME_PM_OPS() dmaengine: pl330: fix bug that cause start the same descs in cyclic dmaengine: at_xdmac: allow muliple dwidths when doing slave transfers dmaengine: at_xdmac: simplify channel configuration stuff dmaengine: at_xdmac: introduce save_cc field dmaengine: at_xdmac: wait for in-progress transaction to complete after pausing a channel ioat: fail self-test if wait_for_completion times out dmaengine: dw: define DW_DMA_MAX_NR_MASTERS dmaengine: dw: amend description of dma_dev field dmatest: move src_off, dst_off, len inside loop ...
2015-02-16Merge tag 'arc-3.20-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc Pull ARC updates from Vineet Gupta: "Some fixes, nothing too exciting this time as well..." * tag 'arc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASE ARC: Fix earlycon build breakage ARC: Dynamically determine BASE_BAUD from DeviceTree arc: Remove unused prepare_to_copy() ARC: use ACCESS_ONCE in cmpxchg loop ARC: add some more comments to ret_from_fork ARC: fix /proc/cpuinfo for offline cpus
2015-02-13ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASEAlexey Brodkin
We used to calculate page address differently in 2 cases: 1. In virt_to_page(x) we do --->8--- mem_map + (x - CONFIG_LINUX_LINK_BASE) >> PAGE_SHIFT --->8--- 2. In in pte_page(x) we do --->8--- mem_map + (pte_val(x) - PAGE_OFFSET) >> PAGE_SHIFT --->8--- That leads to problems in case PAGE_OFFSET != CONFIG_LINUX_LINK_BASE - different pages will be selected depending on where and how we calculate page address. In particular in the STAR 9000853582 when gdb attempted to read memory of another process it got improper page in get_user_pages() because this is exactly one of the places where we search for a page by pte_page(). The fix is trivial - we need to calculate page address similarly in both cases. Cc: <stable@vger.kernel.org> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-12all arches, signal: move restart_block to struct task_structAndy Lutomirski
If an attacker can cause a controlled kernel stack overflow, overwriting the restart block is a very juicy exploit target. This is because the restart_block is held in the same memory allocation as the kernel stack. Moving the restart block to struct task_struct prevents this exploit by making the restart_block harder to locate. Note that there are other fields in thread_info that are also easy targets, at least on some architectures. It's also a decent simplification, since the restart code is more or less identical on all architectures. [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack] Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: David Miller <davem@davemloft.net> Acked-by: Richard Weinberger <richard@nod.at> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Steven Miao <realmz6@gmail.com> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.linux@gmail.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11mm: make FIRST_USER_ADDRESS unsigned long on all archsKirill A. Shutemov
LKP has triggered a compiler warning after my recent patch "mm: account pmd page tables to the process": mm/mmap.c: In function 'exit_mmap': >> mm/mmap.c:2857:2: warning: right shift count >= width of type [enabled by default] The code: > 2857 WARN_ON(mm_nr_pmds(mm) > 2858 round_up(FIRST_USER_ADDRESS, PUD_SIZE) >> PUD_SHIFT); In this, on tile, we have FIRST_USER_ADDRESS defined as 0. round_up() has the same type -- int. PUD_SHIFT. I think the best way to fix it is to define FIRST_USER_ADDRESS as unsigned long. On every arch for consistency. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10arc: drop _PAGE_FILE and pte_file()-related helpersKirill A. Shutemov
We've replaced remap_file_pages(2) implementation with emulation. Nobody creates non-linear mapping anymore. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-04dmaengine: dw: define DW_DMA_MAX_NR_MASTERSAndy Shevchenko
Instead of using magic number in the code the patch provides DW_DMA_MAX_NR_MASTERS constant. While here, restrict the reading of data width array by amount of the actual number of AHB masters. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-02-04ARC: Fix earlycon build breakagePeter Hurley
Commit ffb7fcd66f14 ("ARC: Dynamically determine BASE_BAUD from DeviceTree") breaks arc:defconfig build: drivers/built-in.o: In function `of_setup_earlycon': (.init.text+0xb3e): undefined reference to `arc_early_base_baud' drivers/built-in.o: In function `setup_earlycon': (.init.text+0xcd0): undefined reference to `arc_early_base_baud' make: *** [vmlinux] Error 1 BASE_BAUD is only required for earlycon, which should depend on CONFIG_SERIAL_EARLYCON. Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-02ARC: Dynamically determine BASE_BAUD from DeviceTreeVineet Gupta
8250 earlycon is broken on multi-platform ARC because the UART clk value (BASE_BAUD) is fixed at build time. Instead, determine the appropriate UART clk at runtime; parse the devicetree early for platforms requiring alternate UART clk values (currently only the TB10X platform). Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Rob Herring <robh@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-02arc: Remove unused prepare_to_copy()Tobias Klauser
prepare_to_copy() was removed from all architectures supported at that time in commit 55ccf3fe3f9a ("fork: move the real prepare_to_copy() users to arch_dup_task_struct()"). Remove it from arc as well. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-02ARC: use ACCESS_ONCE in cmpxchg loopVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>