For the 32-bit syscall interface, 64-bit arguments (loff_t) are passed via
a pair of 32-bit registers.  These register pairs end up in consecutive stack
slots, which matches the C ABI for 64-bit arguments.  But when accessing the
registers directly from pt_regs, the wrapper needs to manually reassemble the
64-bit value.  These wrappers already exist for 32-bit compat, so make them
available to 32-bit native in preparation for enabling pt_regs-based syscalls.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Link: https://lkml.kernel.org/r/20200313195144.164260-16-brgerst@gmail.com

Rename the syscalls that only exist for 32-bit from x86_* to ia32_* to make it
clear they are for 32-bit only.  Also rename the functions to match the syscall
name.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Link: https://lkml.kernel.org/r/20200313195144.164260-15-brgerst@gmail.com

After removal of the __ia32_ prefix, remove compat entries that are now
identical to the native entry.

Converted with this script and fixing up whitespace:

while read nr abi name entry compat; do
    if [ "${nr:0:1}" = "#" ]; then
        echo $nr $abi $name $entry $compat
        continue
    fi
    if [ "$entry" = "$compat" ]; then
        compat=""
    fi
    echo "$nr	$abi	$name		$entry		$compat"
done
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200313195144.164260-14-brgerst@gmail.com

Move the ABI prefixes to the __SYSCALL_[abi]() macros.  This allows removal
of the need to strip the prefix for UML.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200313195144.164260-13-brgerst@gmail.com

Add a __SYSCALL_COMMON() macro to the syscall table, which simplifies syscalltbl.sh.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200313195144.164260-12-brgerst@gmail.com

Syscall qualifier support is no longer needed.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Link: https://lkml.kernel.org/r/20200313195144.164260-11-brgerst@gmail.com

Now that the fast syscall path is removed, the ptregs qualifier is unused.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Link: https://lkml.kernel.org/r/20200313195144.164260-10-brgerst@gmail.com

Instead of using an array in asm-offsets to calculate the max syscall
number, calculate it when writing out the syscall headers.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200313195144.164260-9-brgerst@gmail.com

Since X32 has its own syscall table now, move it to a separate file.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Link: https://lkml.kernel.org/r/20200313195144.164260-8-brgerst@gmail.com

so it can be available to multiple syscall tables.  Also directly return
-ENOSYS instead of bouncing to the generic sys_ni_syscall().
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200313195144.164260-7-brgerst@gmail.com

Add missing syscall wrapper for x32_rt_sigreturn().
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200313195144.164260-6-brgerst@gmail.com

Pull the common code out from the SYS_NI macros into a new __SYS_NI macro.
Also conditionalize the X64 version in preparation for enabling syscall
wrappers on 32-bit native kernels.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200313195144.164260-5-brgerst@gmail.com

Pull the common code out from the COND_SYSCALL macros into a new
__COND_SYSCALL macro.  Also conditionalize the X64 version in preparation
for enabling syscall wrappers on 32-bit native kernels.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200313195144.164260-4-brgerst@gmail.com

Pull the common code out from the SYSCALL_DEFINE0 macros into a new
__SYS_STUB0 macro.  Also conditionalize the X64 version in preparation for
enabling syscall wrappers on 32-bit native kernels.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200313195144.164260-3-brgerst@gmail.com

Pull the common code out from the SYSCALL_DEFINEx macros into a new
__SYS_STUBx macro.  Also conditionalize the X64 version in preparation for
enabling syscall wrappers on 32-bit native kernels.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200313195144.164260-2-brgerst@gmail.com

User space cannot disable interrupts any longer so trace return to user space
unconditionally as IRQS_ON.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Link: https://lkml.kernel.org/r/20200308222609.314596327@linutronix.de

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Link: https://lkml.kernel.org/r/20200308222609.219366430@linutronix.de

Nothing cares about the -1 "mark as interrupt" in the errorcode of
exception entries. It's only used to fill the error code when a signal is
delivered, but this is already inconsistent vs. 64 bit as there all
exceptions which do not have an error code set it to 0. So if 32 bit
applications would care about this, then they would have noticed more than
a decade ago.

Just use 0 for all excpetions which do not have an errorcode consistently.

This does neither break /proc/$PID/syscall because this interface examines
the error code / syscall number which is on the stack and that is set to -1
(no syscall) in common_exception unconditionally for all exceptions. The
push in the entry stub is just there to fill the hardware error code slot
on the stack for consistency of the stack layout.

A transient observation of 0 is possible, but that's true for the other
exceptions which use 0 already as well and that interface is an unreliable
snapshot of dubious correctness anyway.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Link: https://lkml.kernel.org/r/87mu94m7ky.fsf@nanos.tec.linutronix.de

#BP is not longer using IST and using ist_enter() and ist_exit() makes it
harder to change ist_enter() and ist_exit()'s behavior.  Instead open-code
the very small amount of required logic.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220217.150607679@linutronix.de

int3 is not using the common_exception path for purely historical reasons,
but there is no reason to keep it the only exception which is different.

Make it use common_exception so the upcoming changes to autogenerate the
entry stubs do not have to special case int3.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220217.042369808@linutronix.de

Nothing is using it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.826870369@linutronix.de

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.720335354@linutronix.de

Add a comment which explains why this empty handler for a reserved vector
exists.
Requested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.624165786@linutronix.de

That function returns immediately after conditionally reenabling interrupts which
is more than pointless and requires the ASM code to disable interrupts again.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20191023123117.871608831@linutronix.de
Link: https://lkml.kernel.org/r/20200225220216.518575042@linutronix.de

Remove the pointless difference between 32 and 64 bit to make further
unifications simpler.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.428188397@linutronix.de

do_machine_check() can be raised in almost any context including the most
fragile ones. Prevent kprobes and tracing.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.315548935@linutronix.de

All exception entry points must have ASM_CLAC right at the
beginning. The general_protection entry is missing one.

Fixes: e59d1b0a ("x86-32, smap: Add STAC/CLAC instructions to 32-bit kernel entry")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200225220216.219537887@linutronix.de

Pull btrfs fixes from David Sterba:
 "These are fixes that were found during testing with help of error
  injection, plus some other stable material.

  There's a fixup to patch added to rc1 causing locking in wrong context
  warnings, tests found one more deadlock scenario. The patches are
  tagged for stable, two of them now in the queue but we'd like all
  three released at the same time.

  I'm not happy about fixes to fixes in such a fast succession during
  rcs, but I hope we found all the fallouts of commit 28553fa9
  ('Btrfs: fix race between shrinking truncate and fiemap')"

* tag 'for-5.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix deadlock during fast fsync when logging prealloc extents beyond eof
  Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extents
  btrfs: fix bytes_may_use underflow in prealloc error condtition
  btrfs: handle logged extent failure properly
  btrfs: do not check delayed items are empty for single transaction cleanup
  btrfs: reset fs_root to NULL on error in open_ctree
  btrfs: destroy qgroup extent records on transaction abort

Pull ext4 fixes from Ted Ts'o:
 "More miscellaneous ext4 bug fixes (all stable fodder)"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix mount failure with quota configured as module
  jbd2: fix ocfs2 corrupt when clearing block group bits
  ext4: fix race between writepages and enabling EXT4_EXTENTS_FL
  ext4: rename s_journal_flag_rwsem to s_writepages_rwsem
  ext4: fix potential race between s_flex_groups online resizing and access
  ext4: fix potential race between s_group_info online resizing and access
  ext4: fix potential race between online resizing and write operations
  ext4: add cond_resched() to __ext4_find_entry()
  ext4: fix a data race in EXT4_I(inode)->i_disksize

Pull csky updates from Guo Ren:
 "Sorry, I missed 5.6-rc1 merge window, but in this pull request the
  most are the fixes and the rests are between fixes and features. The
  only outside modification is the MAINTAINERS file update with our
  mailing list.

   - cache flush implementation fixes

   - ftrace modify panic fix

   - CONFIG_SMP boot problem fix

   - fix pt_regs saving for atomic.S

   - fix fixaddr_init without highmem.

   - fix stack protector support

   - fix fake Tightly-Coupled Memory code compile and use

   - fix some typos and coding convention"

* tag 'csky-for-linus-5.6-rc3' of git://github.com/c-sky/csky-linux: (23 commits)
  csky: Replace <linux/clk-provider.h> by <linux/of_clk.h>
  csky: Implement copy_thread_tls
  csky: Add PCI support
  csky: Minimize defconfig to support buildroot config.fragment
  csky: Add setup_initrd check code
  csky: Cleanup old Kconfig options
  arch/csky: fix some Kconfig typos
  csky: Fixup compile warning for three unimplemented syscalls
  csky: Remove unused cache implementation
  csky: Fixup ftrace modify panic
  csky: Add flush_icache_mm to defer flush icache all
  csky: Optimize abiv2 copy_to_user_page with VM_EXEC
  csky: Enable defer flush_dcache_page for abiv2 cpus (807/810/860)
  csky: Remove unnecessary flush_icache_* implementation
  csky: Support icache flush without specific instructions
  csky/Kconfig: Add Kconfig.platforms to support some drivers
  csky/smp: Fixup boot failed when CONFIG_SMP
  csky: Set regs->usp to kernel sp, when the exception is from kernel
  csky/mm: Fixup export invalid_pte_table symbol
  csky: Separate fixaddr_init from highmem
  ...

The C-Sky platform code is not a clock provider, and just needs to call
of_clk_init().

Hence it can include <linux/of_clk.h> instead of <linux/clk-provider.h>.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

Pull RAS fixes from Thomas Gleixner:
 "Two fixes for the AMD MCE driver:

   - Populate the per CPU MCA bank descriptor pointer only after it has
     been completely set up to prevent a use-after-free in case that one
     of the subsequent initialization step fails

   - Implement a proper release function for the sysfs entries of MCA
     threshold controls instead of freeing the memory right in the CPU
     teardown code, which leads to another use-after-free when the
     associated sysfs file is opened and accessed"

* tag 'ras-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce/amd: Fix kobject lifetime
  x86/mce/amd: Publish the bank pointer only after setup has succeeded

Pull irq fixes from Thomas Gleixner:
 "Two fixes for the irq core code which are follow ups to the recent MSI
  fixes:

   - The WARN_ON which was put into the MSI setaffinity callback for
     paranoia reasons actually triggered via a callchain which escaped
     when all the possible ways to reach that code were analyzed.

     The proc/irq/$N/*affinity interfaces have a quirk which came in
     when ALPHA moved to the generic interface: In case that the written
     affinity mask does not contain any online CPU it calls into ALPHAs
     magic auto affinity setting code.

     A few years later this mechanism was also made available to x86 for
     no good reasons and in a way which circumvents all sanity checks
     for interrupts which cannot have their affinity set from process
     context on X86 due to the way the X86 interrupt delivery works.

     It would be possible to make this work properly, but there is no
     point in doing so. If the interrupt is not yet started then the
     affinity setting has no effect and if it is started already then it
     is already assigned to an online CPU so there is no point to
     randomly move it to some other CPU. Just return EINVAL as the code
     has done before that change forever.

   - The new MSI quirk bit in the irq domain flags turned out to be
     already occupied, which escaped the author and the reviewers
     because the already in use bits were 0,6,2,3,4,5 listed in that
     order.

     That bit 6 was simply overlooked because the ordering was straight
     forward linear otherwise. So the new bit ended up being a
     duplicate.

     Fix it up by switching the oddball 6 to the obvious 1"

* tag 'irq-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/irqdomain: Make sure all irq domain flags are distinct
  genirq/proc: Reject invalid affinity masks (again)

Pull x86 fixes from Thomas Gleixner:
 "Two fixes for x86:

   - Remove the __force_oder definiton from the kaslr boot code as it is
     already defined in the page table code which makes GCC 10 builds
     fail because it changed the default to -fno-common.

   - Address the AMD erratum 1054 concerning the IRPERF capability and
     enable the Instructions Retired fixed counter on machines which are
     not affected by the erratum"

* tag 'x86-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu/amd: Enable the fixed Instructions Retired counter IRPERF
  x86/boot/compressed: Don't declare __force_order in kaslr_64.c

Pull zonefs fix from Damien Le Moal:
 "A single patch fixing typos in the documentation file"

* tag 'zonefs-5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs:
  zonefs: fix documentation typos etc.

Pull io_uring fixes from Jens Axboe:
 "Here's a small collection of fixes that were queued up:

   - Remove unnecessary NULL check (Dan)

   - Missing io_req_cancelled() call in fallocate (Pavel)

   - Put the cleanup check for aux data in the right spot (Pavel)

   - Two fixes for SQPOLL (Stefano, Xiaoguang)"

* tag 'io_uring-5.6-2020-02-22' of git://git.kernel.dk/linux-block:
  io_uring: fix __io_iopoll_check deadlock in io_sq_thread
  io_uring: prevent sq_thread from spinning when it should stop
  io_uring: fix use-after-free by io_cleanup_req()
  io_uring: remove unnecessary NULL checks
  io_uring: add missing io_req_cancelled()

Pull block fixes from Jens Axboe:
 "Just a set of NVMe fixes via Keith"

* tag 'block-5.6-2020-02-22' of git://git.kernel.dk/linux-block:
  nvme-multipath: Fix memory leak with ana_log_buf
  nvme: Fix uninitialized-variable warning
  nvme-pci: Use single IRQ vector for old Apple models
  nvme/pci: Add sleep quirk for Samsung and Toshiba drives

Pull SCSI fixes from James Bottomley:
 "Four non-core fixes.

  Two are reverts of target fixes which turned out to have unwanted side
  effects, one is a revert of an RDMA fix with the same problem and the
  final one fixes an incorrect warning about memory allocation failures
  in megaraid_sas (the driver actually reduces the allocation size until
  it succeeds)"
Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: Revert "target: iscsi: Wait for all commands to finish before freeing a session"
  scsi: Revert "RDMA/isert: Fix a recently introduced regression related to logout"
  scsi: megaraid_sas: silence a warning
  scsi: Revert "target/core: Inline transport_lun_remove_cmd()"

Merge tag 'hwmon-for-v5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:

 - Fix crash in w83627ehf driver seen with W83627DHG-P

 - Fix lockdep splat in acpi_power_meter driver

 - Fix xdpe12284 documentation Sphinx warnings

* tag 'hwmon-for-v5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (w83627ehf) Fix crash seen with W83627DHG-P
  hwmon: (acpi_power_meter) Fix lockdep splat
  Documentation/hwmon: fix xdpe12284 Sphinx warnings