Pull seccomp fixes from Kees Cook:
 "This fixes a rare race condition in seccomp when using TSYNC and
  USER_NOTIF together where a memory allocation would not get freed
  (found by syzkaller, fixed by Tycho).

  Additionally updates Tycho's MAINTAINERS and .mailmap entries for his
  new address"

* tag 'seccomp-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  seccomp: don't leave dangling ->notif if file allocation fails
  mailmap, MAINTAINERS: move to tycho.pizza
  seccomp: don't leak memory when filter install races

Using gcov to collect coverage data for kernels compiled with GCC 10.1
causes random malfunctions and kernel crashes.  This is the result of a
changed GCOV_COUNTERS value in GCC 10.1 that causes a mismatch between
the layout of the gcov_info structure created by GCC profiling code and
the related structure used by the kernel.

Fix this by updating the in-kernel GCOV_COUNTERS value.  Also re-enable
config GCOV_KERNEL for use with GCC 10.

Reported-by: Colin Ian King <colin.king@canonical.com>
Reported-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Tested-by: Leon Romanovsky <leonro@nvidia.com>
Tested-and-Acked-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull crypto fix from Herbert Xu:
 "This fixes a regression in padata"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  padata: fix possible padata_works_lock deadlock

Christian and Kees both pointed out that this is a bit sloppy to open-code
both places, and Christian points out that we leave a dangling pointer to
->notif if file allocation fails. Since we check ->notif for null in order
to determine if it's ok to install a filter, this means people won't be
able to install a filter if the file allocation fails for some reason, even
if they subsequently should be able to.

To fix this, let's hoist this free+null into its own little helper and use
it.

Reported-by: Kees Cook <keescook@chromium.org>
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Tycho Andersen <tycho@tycho.pizza>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200902140953.1201956-1-tycho@tycho.pizza
Signed-off-by: Kees Cook <keescook@chromium.org>

In seccomp_set_mode_filter() with TSYNC | NEW_LISTENER, we first initialize
the listener fd, then check to see if we can actually use it later in
seccomp_may_assign_mode(), which can fail if anyone else in our thread
group has installed a filter and caused some divergence. If we can't, we
partially clean up the newly allocated file: we put the fd, put the file,
but don't actually clean up the *memory* that was allocated at
filter->notif. Let's clean that up too.

To accomplish this, let's hoist the actual "detach a notifier from a
filter" code to its own helper out of seccomp_notify_release(), so that in
case anyone adds stuff to init_listener(), they only have to add the
cleanup code in one spot. This does a bit of extra locking and such on the
failure path when the filter is not attached, but it's a slow failure path
anyway.

Fixes: 51891498f2da ("seccomp: allow TSYNC and USER_NOTIF together")
Reported-by: syzbot+3ad9614a12f80994c32e@syzkaller.appspotmail.com
Signed-off-by: Tycho Andersen <tycho@tycho.pizza>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200902014017.934315-1-tycho@tycho.pizza
Signed-off-by: Kees Cook <keescook@chromium.org>

Pull x86 fixes from Ingo Molnar:

 - more generic entry code ABI fallout

 - debug register handling bugfixes

 - fix vmalloc mappings on 32-bit kernels

 - kprobes instrumentation output fix on 32-bit kernels

 - fix over-eager WARN_ON_ONCE() on !SMAP hardware

 - NUMA debugging fix

 - fix Clang related crash on !RETPOLINE kernels

* tag 'x86-urgent-2020-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry: Unbreak 32bit fast syscall
  x86/debug: Allow a single level of #DB recursion
  x86/entry: Fix AC assertion
  tracing/kprobes, x86/ptrace: Fix regs argument order for i386
  x86, fakenuma: Fix invalid starting node ID
  x86/mm/32: Bring back vmalloc faulting on x86_32
  x86/cmdline: Disable jump tables for cmdline.c

Merge misc fixes from Andrew Morton:
 "19 patches.

  Subsystems affected by this patch series: MAINTAINERS, ipc, fork,
  checkpatch, lib, and mm (memcg, slub, pagemap, madvise, migration,
  hugetlb)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  include/linux/log2.h: add missing () around n in roundup_pow_of_two()
  mm/khugepaged.c: fix khugepaged's request size in collapse_file
  mm/hugetlb: fix a race between hugetlb sysctl handlers
  mm/hugetlb: try preferred node first when alloc gigantic page from cma
  mm/migrate: preserve soft dirty in remove_migration_pte()
  mm/migrate: remove unnecessary is_zone_device_page() check
  mm/rmap: fixup copying of soft dirty and uffd ptes
  mm/migrate: fixup setting UFFD_WP flag
  mm: madvise: fix vma user-after-free
  checkpatch: fix the usage of capture group ( ... )
  fork: adjust sysctl_max_threads definition to match prototype
  ipc: adjust proc_ipc_sem_dointvec definition to match prototype
  mm: track page table modifications in __apply_to_page_range()
  MAINTAINERS: IA64: mark Status as Odd Fixes only
  MAINTAINERS: add LLVM maintainers
  MAINTAINERS: update Cavium/Marvell entries
  mm: slub: fix conversion of freelist_corrupted()
  mm: memcg: fix memcg reclaim soft lockup
  memcg: fix use-after-free in uncharge_batch

Commit 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
changed ctl_table.proc_handler to take a kernel pointer.  Adjust the
definition of sysctl_max_threads to match its prototype in
linux/sysctl.h which fixes the following sparse error/warning:

  kernel/fork.c:3050:47: warning: incorrect type in argument 3 (different address spaces)
  kernel/fork.c:3050:47:    expected void *
  kernel/fork.c:3050:47:    got void [noderef] __user *buffer
  kernel/fork.c:3036:5: error: symbol 'sysctl_max_threads' redeclared with different type (incompatible argument 3 (different address spaces)):
  kernel/fork.c:3036:5:    int extern [addressable] [signed] [toplevel] sysctl_max_threads( ... )
  kernel/fork.c: note: in included file (through include/linux/key.h, include/linux/cred.h, include/linux/sched/signal.h, include/linux/sched/cputime.h):
  include/linux/sysctl.h:242:5: note: previously declared as:
  include/linux/sysctl.h:242:5:    int extern [addressable] [signed] [toplevel] sysctl_max_threads( ... )

Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/20200825093647.24263-1-tklauser@distanz.ch
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

GCOV built with GCC 10 doesn't initialize n_function variable.  This
produces different kernel panics as was seen by Colin in Ubuntu and me
in FC 32.

As a workaround, let's disable GCOV build for broken GCC 10 version.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1891288
Link: https://lore.kernel.org/lkml/20200827133932.3338519-1-leon@kernel.org
Link: https://lore.kernel.org/lkml/CAHk-=whbijeSdSvx-Xcr0DPMj0BiwhJ+uiNnDSVZcr_h_kg7UA@mail.gmail.com/
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Andy reported that the syscall treacing for 32bit fast syscall fails:

# ./tools/testing/selftests/x86/ptrace_syscall_32
...
[RUN] SYSEMU
[FAIL] Initial args are wrong (nr=224, args=10 11 12 13 14 4289172732)
...
[RUN] SYSCALL
[FAIL] Initial args are wrong (nr=29, args=0 0 0 0 0 4289172732)
 
The eason is that the conversion to generic entry code moved the retrieval
of the sixth argument (EBP) after the point where the syscall entry work
runs, i.e. ptrace, seccomp, audit...

Unbreak it by providing a split up version of syscall_enter_from_user_mode().

- syscall_enter_from_user_mode_prepare() establishes state and enables
  interrupts

- syscall_enter_from_user_mode_work() runs the entry work

Replace the call to syscall_enter_from_user_mode() in the 32bit fast
syscall C-entry with the split functions and stick the EBP retrieval
between them.

Fixes: 27d6b4d14f5c ("x86/entry: Use generic syscall entry function")
Reported-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/87k0xdjbtt.fsf@nanos.tec.linutronix.de