- 13 Mar, 2018 40 commits
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Maciej W. Rozycki authored
BugLink: http://bugs.launchpad.net/bugs/1745266 commit c8c5a3a2 upstream. Complement commit c23b3d1a ("MIPS: ptrace: Change GP regset to use correct core dump register layout") and also reject outsized PTRACE_SETREGSET requests to the NT_PRFPREG regset, like with the NT_PRSTATUS regset. Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: c23b3d1a ("MIPS: ptrace: Change GP regset to use correct core dump register layout") Cc: James Hogan <james.hogan@mips.com> Cc: Paul Burton <Paul.Burton@mips.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17930/Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Maciej W. Rozycki authored
BugLink: http://bugs.launchpad.net/bugs/1745266 commit 006501e0 upstream. Complement commit d614fd58 ("mips/ptrace: Preserve previous registers for short regset write") and like with the PTRACE_GETREGSET ptrace(2) request also apply a BUILD_BUG_ON check for the size of the `elf_fpreg_t' type in the PTRACE_SETREGSET request handler. Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: d614fd58 ("mips/ptrace: Preserve previous registers for short regset write") Cc: James Hogan <james.hogan@mips.com> Cc: Paul Burton <Paul.Burton@mips.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17929/Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Maciej W. Rozycki authored
BugLink: http://bugs.launchpad.net/bugs/1745266 commit be07a6a1 upstream. Fix a commit 72b22bba ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84 ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bba ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17928/Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Maciej W. Rozycki authored
BugLink: http://bugs.launchpad.net/bugs/1745266 commit 80b3ffce upstream. Update commit d614fd58 ("mips/ptrace: Preserve previous registers for short regset write") bug and consistently consume all data supplied to `fpr_set_msa' with the ptrace(2) PTRACE_SETREGSET request, such that a zero data buffer counter is returned where insufficient data has been given to fill a whole number of FP general registers. In reality this is not going to happen, as the caller is supposed to only supply data covering a whole number of registers and it is verified in `ptrace_regset' and again asserted in `fpr_set', however structuring code such that the presence of trailing partial FP general register data causes `fpr_set_msa' to return with a non-zero data buffer counter makes it appear that this trailing data will be used if there are subsequent writes made to FP registers, which is going to be the case with the FCSR once the missing write to that register has been fixed. Fixes: d614fd58 ("mips/ptrace: Preserve previous registers for short regset write") Signed-off-by: Maciej W. Rozycki <macro@mips.com> Cc: James Hogan <james.hogan@mips.com> Cc: Paul Burton <Paul.Burton@mips.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17927/Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Maciej W. Rozycki authored
BugLink: http://bugs.launchpad.net/bugs/1745266 commit dc24d0ed upstream. Complement commit d614fd58 ("mips/ptrace: Preserve previous registers for short regset write") and ensure that no partial register write attempt is made with PTRACE_SETREGSET, as we do not preinitialize any temporaries used to hold incoming register data and consequently random data could be written. It is the responsibility of the caller, such as `ptrace_regset', to arrange for writes to span whole registers only, so here we only assert that it has indeed happened. Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bba ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: James Hogan <james.hogan@mips.com> Cc: Paul Burton <Paul.Burton@mips.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17926/Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Maciej W. Rozycki authored
BugLink: http://bugs.launchpad.net/bugs/1745266 commit a03fe725 upstream. In preparation to fix a commit 72b22bba ("MIPS: Don't assume 64-bit FP registers for FP regset") FCSR access regression factor out NT_PRFPREG regset access helpers for the non-MSA and the MSA variants respectively, to avoid having to deal with excessive indentation in the actual fix. No functional change, however use `target->thread.fpu.fpr[0]' rather than `target->thread.fpu.fpr[i]' for FGR holding type size determination as there's no `i' variable to refer to anymore, and for the factored out `i' variable declaration use `unsigned int' rather than `unsigned' as its type, following the common style. Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bba ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: James Hogan <james.hogan@mips.com> Cc: Paul Burton <Paul.Burton@mips.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17925/Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Maciej W. Rozycki authored
BugLink: http://bugs.launchpad.net/bugs/1745266 commit b67336ee upstream. Fix an API loophole introduced with commit 9791554b ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS"), where the caller of prctl(2) is incorrectly allowed to make a change to CP0.Status.FR or CP0.Config5.FRE register bits even if CONFIG_MIPS_O32_FP64_SUPPORT has not been enabled, despite that an executable requesting the mode requested via ELF file annotation would not be allowed to run in the first place, or for n64 and n64 ABI tasks which do not have non-default modes defined at all. Add suitable checks to `mips_set_process_fp_mode' and bail out if an invalid mode change has been requested for the ABI in effect, even if the FPU hardware or emulation would otherwise allow it. Always succeed however without taking any further action if the mode requested is the same as one already in effect, regardless of whether any mode change, should it be requested, would actually be allowed for the task concerned. Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 9791554b ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS") Reviewed-by: Paul Burton <paul.burton@mips.com> Cc: James Hogan <james.hogan@mips.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17800/Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Bart Van Assche authored
BugLink: http://bugs.launchpad.net/bugs/1745266 commit bec40c26 upstream. With the SRP protocol all RDMA operations are initiated by the target. Since no RDMA operations are initiated by the initiator, do not grant the initiator permission to submit RDMA reads or writes to the target. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Wolfgang Grandegger authored
BugLink: http://bugs.launchpad.net/bugs/1745266 commit d5b42e66 upstream. The "set_bittiming" callback treats a positive return value as error! For that reason "can_changelink()" will quit silently after setting the bittiming values without processing ctrlmode, restart-ms, etc. Signed-off-by: Wolfgang Grandegger <wg@grandegger.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Suren Baghdasaryan authored
BugLink: http://bugs.launchpad.net/bugs/1745266 commit fbc7c07e upstream. When system is under memory pressure it is observed that dm bufio shrinker often reclaims only one buffer per scan. This change fixes the following two issues in dm bufio shrinker that cause this behavior: 1. ((nr_to_scan - freed) <= retain_target) condition is used to terminate slab scan process. This assumes that nr_to_scan is equal to the LRU size, which might not be correct because do_shrink_slab() in vmscan.c calculates nr_to_scan using multiple inputs. As a result when nr_to_scan is less than retain_target (64) the scan will terminate after the first iteration, effectively reclaiming one buffer per scan and making scans very inefficient. This hurts vmscan performance especially because mutex is acquired/released every time dm_bufio_shrink_scan() is called. New implementation uses ((LRU size - freed) <= retain_target) condition for scan termination. LRU size can be safely determined inside __scan() because this function is called after dm_bufio_lock(). 2. do_shrink_slab() uses value returned by dm_bufio_shrink_count() to determine number of freeable objects in the slab. However dm_bufio always retains retain_target buffers in its LRU and will terminate a scan when this mark is reached. Therefore returning the entire LRU size from dm_bufio_shrink_count() is misleading because that does not represent the number of freeable objects that slab will reclaim during a scan. Returning (LRU size - retain_target) better represents the number of freeable objects in the slab. This way do_shrink_slab() returns 0 when (LRU size < retain_target) and vmscan will not try to scan this shrinker avoiding scans that will not reclaim any memory. Test: tested using Android device running <AOSP>/system/extras/alloc-stress that generates memory pressure and causes intensive shrinker scans Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Greg Kroah-Hartman authored
BugLink: http://bugs.launchpad.net/bugs/1745263Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Greg Kroah-Hartman authored
BugLink: http://bugs.launchpad.net/bugs/1745263 This fixes the following much-reported build issue: arch/x86/entry/vdso/vma.c: In function ‘map_vdso’: arch/x86/entry/vdso/vma.c:175:9: error: implicit declaration of function ‘pvclock_pvti_cpu0_va’ on some arches and configurations. Thanks to Guenter for being persistent enough to get it fixed :) Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Alexey Dobriyan authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit 68ba0326 upstream. Every current KDE system has process named ksysguardd polling files below once in several seconds: $ strace -e trace=open -p $(pidof ksysguardd) Process 1812 attached open("/etc/mtab", O_RDONLY|O_CLOEXEC) = 8 open("/etc/mtab", O_RDONLY|O_CLOEXEC) = 8 open("/proc/net/dev", O_RDONLY) = 8 open("/proc/net/wireless", O_RDONLY) = -1 ENOENT (No such file or directory) open("/proc/stat", O_RDONLY) = 8 open("/proc/vmstat", O_RDONLY) = 8 Hell knows what it is doing but speed up reading /proc/vmstat by 33%! Benchmark is open+read+close 1.000.000 times. BEFORE $ perf stat -r 10 taskset -c 3 ./proc-vmstat Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs): 13146.768464 task-clock (msec) # 0.960 CPUs utilized ( +- 0.60% ) 15 context-switches # 0.001 K/sec ( +- 1.41% ) 1 cpu-migrations # 0.000 K/sec ( +- 11.11% ) 104 page-faults # 0.008 K/sec ( +- 0.57% ) 45,489,799,349 cycles # 3.460 GHz ( +- 0.03% ) 9,970,175,743 stalled-cycles-frontend # 21.92% frontend cycles idle ( +- 0.10% ) 2,800,298,015 stalled-cycles-backend # 6.16% backend cycles idle ( +- 0.32% ) 79,241,190,850 instructions # 1.74 insn per cycle # 0.13 stalled cycles per insn ( +- 0.00% ) 17,616,096,146 branches # 1339.956 M/sec ( +- 0.00% ) 176,106,232 branch-misses # 1.00% of all branches ( +- 0.18% ) 13.691078109 seconds time elapsed ( +- 0.03% ) ^^^^^^^^^^^^ AFTER $ perf stat -r 10 taskset -c 3 ./proc-vmstat Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs): 8688.353749 task-clock (msec) # 0.950 CPUs utilized ( +- 1.25% ) 10 context-switches # 0.001 K/sec ( +- 2.13% ) 1 cpu-migrations # 0.000 K/sec 104 page-faults # 0.012 K/sec ( +- 0.56% ) 30,384,010,730 cycles # 3.497 GHz ( +- 0.07% ) 12,296,259,407 stalled-cycles-frontend # 40.47% frontend cycles idle ( +- 0.13% ) 3,370,668,651 stalled-cycles-backend # 11.09% backend cycles idle ( +- 0.69% ) 28,969,052,879 instructions # 0.95 insn per cycle # 0.42 stalled cycles per insn ( +- 0.01% ) 6,308,245,891 branches # 726.058 M/sec ( +- 0.00% ) 214,685,502 branch-misses # 3.40% of all branches ( +- 0.26% ) 9.146081052 seconds time elapsed ( +- 0.07% ) ^^^^^^^^^^^ vsnprintf() is slow because: 1. format_decode() is busy looking for format specifier: 2 branches per character (not in this case, but in others) 2. approximately million branches while parsing format mini language and everywhere 3. just look at what string() does /proc/vmstat is good case because most of its content are strings Link: http://lkml.kernel.org/r/20160806125455.GA1187@p183.telecom.bySigned-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Libor Pechacek authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit 3205c36c upstream. While most of the locations where a kernel taint bit is set are accompanied with a warning message, there are two which set their bits silently. If the tainting module gets unloaded later on, it is almost impossible to tell what was the reason for setting the flag. Signed-off-by: Libor Pechacek <lpechacek@suse.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Michal Marek authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit a78f70e8 upstream. The reference files use spaces to separate tokens, however, we must preserve spaces inside string literals. Currently the only case in the tree is struct edac_raw_error_desc in <linux/edac.h>: $ KBUILD_SYMTYPES=1 make -s drivers/edac/amd64_edac.symtypes $ mv drivers/edac/amd64_edac.{symtypes,symref} $ KBUILD_SYMTYPES=1 make -s drivers/edac/amd64_edac.symtypes drivers/edac/amd64_edac.c:527: warning: amd64_get_dram_hole_info: modversion changed because of changes in struct edac_raw_error_desc Signed-off-by: Michal Marek <mmarek@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Helge Deller authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit 88776c0e upstream. Qemu for PARISC reported on a 32bit SMP parisc kernel strange failures about "Not-handled unaligned insn 0x0e8011d6 and 0x0c2011c9." Those opcodes evaluate to the ldcw() assembly instruction which requires (on 32bit) an alignment of 16 bytes to ensure atomicity. As it turns out, qemu is correct and in our assembly code in entry.S and pacache.S we don't pay attention to the required alignment. This patch fixes the problem by aligning the lock offset in assembly code in the same manner as we do in our C-code. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Vineet Gupta authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit 79435ac7 upstream. This used to setup the LP_COUNT register automatically, but now has been removed. There was an earlier fix 3c7c7a2f which fixed instance in delay.h but somehow missed this one as gcc change had not made its way into production toolchains and was not pedantic as it is now ! Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Oleg Nesterov authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit 42691579 upstream. complete_signal() checks SIGNAL_UNKILLABLE before it starts to destroy the thread group, today this is wrong in many ways. If nothing else, fatal_signal_pending() should always imply that the whole thread group (except ->group_exit_task if it is not NULL) is killed, this check breaks the rule. After the previous changes we can rely on sig_task_ignored(); sig_fatal(sig) && SIGNAL_UNKILLABLE can only be true if we actually want to kill this task and sig == SIGKILL OR it is traced and debugger can intercept the signal. This should hopefully fix the problem reported by Dmitry. This test-case static int init(void *arg) { for (;;) pause(); } int main(void) { char stack[16 * 1024]; for (;;) { int pid = clone(init, stack + sizeof(stack)/2, CLONE_NEWPID | SIGCHLD, NULL); assert(pid > 0); assert(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0); assert(waitpid(-1, NULL, WSTOPPED) == pid); assert(ptrace(PTRACE_DETACH, pid, 0, SIGSTOP) == 0); assert(syscall(__NR_tkill, pid, SIGKILL) == 0); assert(pid == wait(NULL)); } } triggers the WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING)) in task_participate_group_stop(). do_signal_stop()->signal_group_exit() checks SIGNAL_GROUP_EXIT and return false, but task_set_jobctl_pending() checks fatal_signal_pending() and does not set JOBCTL_STOP_PENDING. And his should fix the minor security problem reported by Kyle, SECCOMP_RET_TRACE can miss fatal_signal_pending() the same way if the task is the root of a pid namespace. Link: http://lkml.kernel.org/r/20171103184246.GD21036@redhat.comSigned-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Kyle Huey <me@kylehuey.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kyle Huey <me@kylehuey.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Oleg Nesterov authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit ac253850 upstream. Change sig_task_ignored() to drop the SIG_DFL && !sig_kernel_only() signals even if force == T. This simplifies the next change and this matches the same check in get_signal() which will drop these signals anyway. Link: http://lkml.kernel.org/r/20171103184227.GC21036@redhat.comSigned-off-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Kyle Huey <me@kylehuey.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Oleg Nesterov authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit 628c1bcb upstream. The comment in sig_ignored() says "Tracers may want to know about even ignored signals" but SIGKILL can not be reported to debugger and it is just wrong to return 0 in this case: SIGKILL should only kill the SIGNAL_UNKILLABLE task if it comes from the parent ns. Change sig_ignored() to ignore ->ptrace if sig == SIGKILL and rely on sig_task_ignored(). SISGTOP coming from within the namespace is not really right too but at least debugger can intercept it, and we can't drop it here because this will break "gdb -p 1": ptrace_attach() won't work. Perhaps we will add another ->ptrace check later, we will see. Link: http://lkml.kernel.org/r/20171103184206.GB21036@redhat.comSigned-off-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Kyle Huey <me@kylehuey.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Thiago Rafael Becker authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit bdcf0a42 upstream. In testing, we found that nfsd threads may call set_groups in parallel for the same entry cached in auth.unix.gid, racing in the call of groups_sort, corrupting the groups for that entry and leading to permission denials for the client. This patch: - Make groups_sort globally visible. - Move the call to groups_sort to the modifiers of group_info - Remove the call to groups_sort from set_groups Link: http://lkml.kernel.org/r/20171211151420.18655-1-thiago.becker@gmail.comSigned-off-by: Thiago Rafael Becker <thiago.becker@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: NeilBrown <neilb@suse.com> Acked-by: "J. Bruce Fields" <bfields@fieldses.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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David Howells authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit 98801506 upstream. Fix the default for fscache_maybe_release_page() for when the cookie isn't valid or the page isn't cached. It mustn't return false as that indicates the page cannot yet be freed. The problem with the default is that if, say, there's no cache, but a network filesystem's pages are using up almost all the available memory, a system can OOM because the filesystem ->releasepage() op will not allow them to be released as fscache_maybe_release_page() incorrectly prevents it. This can be tested by writing a sequence of 512MiB files to an AFS mount. It does not affect NFS or CIFS because both of those wrap the call in a check of PG_fscache and it shouldn't bother Ceph as that only has PG_private set whilst writeback is in progress. This might be an issue for 9P, however. Note that the pages aren't entirely stuck. Removing a file or unmounting will clear things because that uses ->invalidatepage() instead. Fixes: 201a1542 ("FS-Cache: Handle pages pending storage that get evicted under OOM conditions") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Stefan Brüns authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit e2bf801e upstream. Include the OF-based modalias in the uevent sent when registering devices on the sunxi RSB bus, so that user space has a chance to autoload the kernel module for the device. Fixes a regression caused by commit 3f241bfa ("arm64: allwinner: a64: pine64: Use dcdc1 regulator for mmc0"). When the axp20x-rsb module for the AXP803 PMIC is built as a module, it is not loaded and the system ends up with an disfunctional MMC controller. Fixes: d787dcdb ("bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus") Acked-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Eric Biggers authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit d76c6810 upstream. pcrypt is using the old way of freeing instances, where the ->free() method specified in the 'struct crypto_template' is passed a pointer to the 'struct crypto_instance'. But the crypto_instance is being kfree()'d directly, which is incorrect because the memory was actually allocated as an aead_instance, which contains the crypto_instance at a nonzero offset. Thus, the wrong pointer was being kfree()'d. Fix it by switching to the new way to free aead_instance's where the ->free() method is specified in the aead_instance itself. Reported-by: syzbot <syzkaller@googlegroups.com> Fixes: 0496f560 ("crypto: pcrypt - Add support for new AEAD interface") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Eric Biggers authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit e57121d0 upstream. If the rfc7539 template was instantiated with a hash algorithm with digest size larger than 16 bytes (POLY1305_DIGEST_SIZE), then the digest overran the 'tag' buffer in 'struct chachapoly_req_ctx', corrupting the subsequent memory, including 'cryptlen'. This caused a crash during crypto_skcipher_decrypt(). Fix it by, when instantiating the template, requiring that the underlying hash algorithm has the digest size expected for Poly1305. Reproducer: #include <linux/if_alg.h> #include <sys/socket.h> #include <unistd.h> int main() { int algfd, reqfd; struct sockaddr_alg addr = { .salg_type = "aead", .salg_name = "rfc7539(chacha20,sha256)", }; unsigned char buf[32] = { 0 }; algfd = socket(AF_ALG, SOCK_SEQPACKET, 0); bind(algfd, (void *)&addr, sizeof(addr)); setsockopt(algfd, SOL_ALG, ALG_SET_KEY, buf, sizeof(buf)); reqfd = accept(algfd, 0, 0); write(reqfd, buf, 16); read(reqfd, buf, 16); } Reported-by: syzbot <syzkaller@googlegroups.com> Fixes: 71ebc4d1 ("crypto: chacha20poly1305 - Add a ChaCha20-Poly1305 AEAD construction, RFC7539") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Jan Engelhardt authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit 203f4500 upstream. queue_cache_init is first called for the Control Word Queue (n2_crypto_probe). At that time, queue_cache[0] is NULL and a new kmem_cache will be allocated. If the subsequent n2_register_algs call fails, the kmem_cache will be released in queue_cache_destroy, but queue_cache_init[0] is not set back to NULL. So when the Module Arithmetic Unit gets probed next (n2_mau_probe), queue_cache_init will not allocate a kmem_cache again, but leave it as its bogus value, causing a BUG() to trigger when queue_cache[0] is eventually passed to kmem_cache_zalloc: n2_crypto: Found N2CP at /virtual-devices@100/n2cp@7 n2_crypto: Registered NCS HVAPI version 2.0 called queue_cache_init n2_crypto: md5 alg registration failed n2cp f028687c: /virtual-devices@100/n2cp@7: Unable to register algorithms. called queue_cache_destroy n2cp: probe of f028687c failed with error -22 n2_crypto: Found NCP at /virtual-devices@100/ncp@6 n2_crypto: Registered NCS HVAPI version 2.0 called queue_cache_init kernel BUG at mm/slab.c:2993! Call Trace: [0000000000604488] kmem_cache_alloc+0x1a8/0x1e0 (inlined) kmem_cache_zalloc (inlined) new_queue (inlined) spu_queue_setup (inlined) handle_exec_unit [0000000010c61eb4] spu_mdesc_scan+0x1f4/0x460 [n2_crypto] [0000000010c62b80] n2_mau_probe+0x100/0x220 [n2_crypto] [000000000084b174] platform_drv_probe+0x34/0xc0 Signed-off-by: Jan Engelhardt <jengelh@inai.de> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Oleg Nesterov authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit 4d957015 upstream. As Tsukada explains, the time_is_before_jiffies(acct->needcheck) check is very wrong, we need time_is_after_jiffies() to make sys_acct() work. Ignoring the overflows, the code should "goto out" if needcheck > jiffies, while currently it checks "needcheck < jiffies" and thus in the likely case check_free_space() does nothing until jiffies overflow. In particular this means that sys_acct() is simply broken, acct_on() sets acct->needcheck = jiffies and expects that check_free_space() should set acct->active = 1 after the free-space check, but this won't happen if jiffies increments in between. This was broken by commit 32dc7308 ("get rid of timer in kern/acct.c") in 2011, then another (correct) commit 795a2f22 ("acct() should honour the limits from the very beginning") made the problem more visible. Link: http://lkml.kernel.org/r/20171213133940.GA6554@redhat.com Fixes: 32dc7308 ("get rid of timer in kern/acct.c") Reported-by: TSUKADA Koutaro <tsukada@ascade.co.jp> Suggested-by: TSUKADA Koutaro <tsukada@ascade.co.jp> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Andrey Ryabinin authored
BugLink: http://bugs.launchpad.net/bugs/1745263 commit 063fb3e5 upstream. After kasan_init() executed, no one is allowed to write to kasan_zero_page, so write protect it. Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1452516679-32040-3-git-send-email-aryabinin@virtuozzo.comSigned-off-by: Ingo Molnar <mingo@kernel.org> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Daniel Axtens authored
BugLink: https://bugs.launchpad.net/bugs/1745364 Coverity reports: *** CID 1464330: Uninitialized variables (MISSING_RETURN) /arch/x86/net/bpf_jit_comp.c: 1088 in bpf_int_jit_compile() 1082 int i; 1083 1084 if (!bpf_jit_enable) 1085 return prog; 1086 1087 if (!prog || !prog->len) >>> >>> CID 1464330: Uninitialized variables (MISSING_RETURN) >>> >>> Arriving at the end of a function without returning a value. 1088 return; 1089 1090 addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); 1091 if (!addrs) 1092 return prog; 1093 This is a result of 3098d8ea ("bpf: prepare bpf_int_jit_compile/bpf_prog_select_runtime apis"), which is a cherry-pick of d1c55ab5 upstream. In that patch, the return type of bpf_int_jit_compile was changed from void to struct bpf_prog*. That patch changed some of the return statements. It did not change the return statement of the (!prog || !prog->len) check, as in upstream the (!prog || !prog->len) check was dropped in 93a73d44 ("bpf, x86/arm64: remove useless checks on prog"): """ There is never such a situation, where bpf_int_jit_compile() is called with either prog as NULL or len as 0, so the tests are unnecessary and confusing as people would just copy them. """ However, we haven't picked up 93a73d44, so when we cherry-picked d1c55ab5, that branch remained unmodified, hence the static analysis warning. For consistency and in case the branch is not actually dead on Xenial, do a fixup to 'return prog;' Fixes: 3098d8ea ("bpf: prepare bpf_int_jit_compile/bpf_prog_select_runtime apis") Cc: Andy Whitcroft <apw@canonical.com> Cc: Colin King <colin.king@canonical.com> Signed-off-by: Daniel Axtens <daniel.axtens@canonical.com> Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> Acked-by: Khalid Elmously <khalid.elmously@canonical.com> [klebers: fixed context] Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
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Heiko Carstens authored
BugLink: http://bugs.launchpad.net/bugs/1744736 Add a new line to /proc/cpuinfo which shows all available facilities as reported by the stfle instruction: > cat /proc/cpuinfo ... facilities : 0 1 2 3 4 6 7 ... ... Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> (back ported from commit 157467ba) Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com> Acked-by: Khalid Elmously <khalid.elmously@canonical.com> Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
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Heiko Carstens authored
BugLink: http://bugs.launchpad.net/bugs/1744736 Same helper function like for_each_set_bit in generic code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> (cherry picked from commit 09214545) Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com> Acked-by: Khalid Elmously <khalid.elmously@canonical.com> Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
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Greg Kroah-Hartman authored
BugLink: http://bugs.launchpad.net/bugs/1745071Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Khalid Elmously authored
BugLink: http://bugs.launchpad.net/bugs/1745071Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com> [ klebers: added BugLink ] Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
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Kees Cook authored
BugLink: http://bugs.launchpad.net/bugs/1745071 This renames CONFIG_KAISER to CONFIG_PAGE_TABLE_ISOLATION. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Greg Kroah-Hartman authored
BugLink: http://bugs.launchpad.net/bugs/1745069Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Andy Lutomirski authored
BugLink: http://bugs.launchpad.net/bugs/1745069 commit 5dd0b16c upstream. This fixes CONFIG_SMP=n, CONFIG_DEBUG_TLBFLUSH=y without introducing further #ifdef soup. Caught by a Kbuild bot randconfig build. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: ce4a4e56 ("x86/mm: Remove the UP asm/tlbflush.h code, always use the (formerly) SMP code") Link: http://lkml.kernel.org/r/76da9a3cc4415996f2ad2c905b93414add322021.1496673616.git.luto@kernel.orgSigned-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Linus Torvalds authored
BugLink: http://bugs.launchpad.net/bugs/1745069 commit 966031f3 upstream. We added support for EXTPROC back in 2010 in commit 26df6d13 ("tty: Add EXTPROC support for LINEMODE") and the intent was to allow it to override some (all?) ICANON behavior. Quoting from that original commit message: There is a new bit in the termios local flag word, EXTPROC. When this bit is set, several aspects of the terminal driver are disabled. Input line editing, character echo, and mapping of signals are all disabled. This allows the telnetd to turn off these functions when in linemode, but still keep track of what state the user wants the terminal to be in. but the problem turns out that "several aspects of the terminal driver are disabled" is a bit ambiguous, and you can really confuse the n_tty layer by setting EXTPROC and then causing some of the ICANON invariants to no longer be maintained. This fixes at least one such case (TIOCINQ) becoming unhappy because of the confusion over whether ICANON really means ICANON when EXTPROC is set. This basically makes TIOCINQ match the case of read: if EXTPROC is set, we ignore ICANON. Also, make sure to reset the ICANON state ie EXTPROC changes, not just if ICANON changes. Fixes: 26df6d13 ("tty: Add EXTPROC support for LINEMODE") Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Reported-by: syzkaller <syzkaller@googlegroups.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Thomas Gleixner authored
BugLink: http://bugs.launchpad.net/bugs/1745069 commit 322f8b8b upstream. smpboot_setup_warm_reset_vector() and smpboot_restore_warm_reset_vector() invoke local_flush_tlb() for no obvious reason. Digging in history revealed that the original code in the 2.1 era added those because the code manipulated a swapper_pg_dir pagetable entry. The pagetable manipulation was removed long ago in the 2.3 timeframe, but the TLB flush invocations stayed around forever. Remove them along with the pointless pr_debug()s which come from the same 2.1 change. Reported-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20171230211829.586548655@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Thomas Gleixner authored
BugLink: http://bugs.launchpad.net/bugs/1745069 commit 5d62c183 upstream. The conditions in irq_exit() to invoke tick_nohz_irq_exit() which subsequently invokes tick_nohz_stop_sched_tick() are: if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu)) If need_resched() is not set, but a timer softirq is pending then this is an indication that the softirq code punted and delegated the execution to softirqd. need_resched() is not true because the current interrupted task takes precedence over softirqd. Invoking tick_nohz_irq_exit() in this case can cause an endless loop of timer interrupts because the timer wheel contains an expired timer, but softirqs are not yet executed. So it returns an immediate expiry request, which causes the timer to fire immediately again. Lather, rinse and repeat.... Prevent that by adding a check for a pending timer soft interrupt to the conditions in tick_nohz_stop_sched_tick() which avoid calling get_next_timer_interrupt(). That keeps the tick sched timer on the tick and prevents a repetitive programming of an already expired timer. Reported-by: Sebastian Siewior <bigeasy@linutronix.d> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Anna-Maria Gleixner <anna-maria@linutronix.de> Cc: Sebastian Siewior <bigeasy@linutronix.de> Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712272156050.2431@nanosSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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Daniel Thompson authored
BugLink: http://bugs.launchpad.net/bugs/1745069 commit da997066 upstream. When plugging in a USB webcam I see the following message: xhci_hcd 0000:04:00.0: WARN Successful completion on short TX: needs XHCI_TRUST_TX_LENGTH quirk? handle_tx_event: 913 callbacks suppressed All is quiet again with this patch (and I've done a fair but of soak testing with the camera since). Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
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