Age | Commit message (Collapse) | Author |
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Use get_tod_clock_fast() instead of store_tod_clock(), since
store_tod_clock() can be very slow.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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The stck/stckf instruction used within the inline assembly within
do_account_vtime() changes the condition code. This is not reflected
with the clobber list, and therefore might result in incorrect code
generation.
It seems unlikely that the compiler could generate incorrect code
considering the surrounding C code, but it must still be fixed.
Cc: <stable@vger.kernel.org>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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This is the s390 variant of commit e6b28ec65b6d ("x86/vdso: On timens
page fault prefault also VVAR page").
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Implement generic vdso time namespace support which also enables time
namespaces for s390. This is quite similar to what arm64 has.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Use the passed in vdso_data pointer instead of calculating it again.
This is also required as a prerequisite for vdso time namespaces: if a
process is part of a time namespace __arch_get_vdso_data() will return
a pointer to the time namespace data page instead of the vdso data
page, which is not what __arch_get_hw_counter() expects.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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For consistency with x86 and arm64 move the data page before code
pages. Similar to commit 601255ae3c98 ("arm64: vdso: move data page
before code pages").
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Add a separate "[vvar]" mapping for the vdso datapage, since it
doesn't need to be executable or COW-able.
This is actually the s390 implementation of commit 871549385278
("arm64: vdso: put vdso datapage in a separate vma")
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Implement vdso mapping similar to arm64 and powerpc.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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- remove unneeded includes
- move functions around
- remove obvious and/or incorrect comments
- shorten some if conditions
No functional change.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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A few local variables exist only so the contents of a global variable
can be copied to them, and use that value only for reading.
Just remove them and rename some global variables. Also change
vdso64_[start|end] to be character arrays to be consistent with other
architectures, and get rid of the global variable vdso64_kbase.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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vdso_pages (aka vdso64_pages) is never 0, therefore remove the check.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Handle allocation error gracefully and simply disable vdso instead of
leaving the system in an undefined state.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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The vdso is (and must) be page aligned and its size must also be
a multiple of PAGE_SIZE. Therefore no need to round upwards.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Convert vdso_init() to arch_initcall like it is on all other architectures.
This requires to remove the vdso_getcpu_init() call from vdso_init()
since it must be called before smp is enabled.
vdso_getcpu_init() is now an early_initcall like on powerpc.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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The vdso data page actually contains an array. Fix that.
This doesn't fix a real bug, just reflects reality.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Since Fedora 33 the virtualization stack of Fedora requires a couple of
netfilter modules to function properly. Let's add these to defconfig and
debug_defconfig.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Tested-by: Bjoern Walk <bwalk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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...but set it to off by default. Use the kernel command line option
`kmemleak=on` to enable it.
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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The GitHub organisation name under which the s390-tools package is being
hosted has changed. Update the web link.
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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When a msg is retried because the lower ap layer returns -EAGAIN
there is a retry limit (currently 10). When this limit is reached
the last return code from the lower layer is returned, causing
the userspace to get -1 on the ioctl with errno EAGAIN.
This EAGAIN is misleading here. After 10 retry attempts the
userspace should receive a clear failure indication like EINVAL
or EIO or ENODEV. However, the reason why these retries all
fail is unclear. On an invalid message EINVAL would be returned
by the lower layer, and if devices go away or are not available
an ENODEV is seen. So this patch now reworks the retry loops
to return EIO to userspace when the retry limit is reached.
Fixes: 91ffc519c199 ("s390/zcrypt: introduce msg tracking in zcrypt functions")
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Add missing forward declaration for task_struct.
The warning appears when the -Werror C compiler flag is being used.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Disable CONFIG_TMPFS_INODE64 which is currently broken on s390x
because size of ino_t on s390x is 4 bytes.
This fixes the following error with kdump:
[ 9.415082] [608]: Remounting '/' read-only in with options 'size=238372k,nr_inodes=59593,inode64'.
[ 9.415093] rootfs: Cannot use inode64 with <64bit inums in kernel
[ 9.415093]
[ 9.415100] [608]: Failed to remount '/' read-only: Invalid argument
Fixes: 5c60ed283e1d ("s390: update defconfigs")
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Fix the following coccicheck warnings:
./arch/s390/include/asm/scsw.h:528:48-50: WARNING !A || A && B is
equivalent to !A || B.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Zhong <abaci-bugfix@linux.alibaba.com>
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Remove a superfluous semicolon after function definition.
Signed-off-by: Chengyang Fan <cy.fan@huawei.com>
Message-Id: <20210125095839.1720265-1-cy.fan@huawei.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Currently zpci_create_device() is only called in clp_add_pci_device()
which allocates the memory for the struct zpci_dev being created. There
is little separation of concerns as only both functions together can
create a zpci_dev and the only CLP specific code in
clp_add_pci_device() is a call to clp_query_pci_fn().
Improve this by removing clp_add_pci_device() and refactor
zpci_create_device() such that it alone creates and initializes the
zpci_dev given the FID and Function Handle. For this we need to make
clp_query_pci_fn() non-static. While at it remove the function handle
parameter since we can just take that from the zpci_dev. Also move
adding to the zpci_list to after the zdev has been fully created which
eliminates a window where a partially initialized zdev can be found by
get_zdev_by_fid().
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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We currently track the time of the most recent QDIO Adapter Interrupt.
This is a system-wide timestamp (as such interrupts are not bound to
one specific qdio device).
If interrupt processing stalls on one device but is functional for a
different device, the timestamp continues to be updated and is of no
help for problem diagnosis.
So for debugging purposes also track the time of the last Data IRQ on
a per-device level. Collect this data in the legacy non-AI path as well.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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tiqdio_add_device() adds the device to the tiq_list of eligible targets
for a data IRQ, which gets walked on each QDIO Adapter Interrupt to
inspect their DSCIs.
But currently the tiqdio_add_device() / tiqdio_remove_device() calls
are not symmetric - the device is removed within qdio_shutdown(),
but only added by qdio_activate().
So depending on the call sequence and encountered errors, we might
be trying to remove a list entry in qdio_shutdown() that was never even
added to the list. This required additional INIT_LIST_HEAD() calls to
ensure that the list entry was always in a consistent state.
All drivers now fence the IRQ delivery via qdio_start_irq() /
qdio_stop_irq(), so we can nicely integrate this tiq_list management
with the other steps needed for QDIO Adapter IRQ (de-)registration
(qdio_establish_thinint() / qdio_shutdown_thinint()).
As the naming suggests these get called during qdio_establish() and
qdio_shutdown(), with proper symmetry and roll-back after errors.
With this we longer need to worry about misplaced list removals, and
thus can clean up the list API abuse (INIT_LIST_HEAD() should not be
called on list entries).
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Convert the Output Queue tasklet code to take a tasklet_struct as
parameter. Then initialize the tasklet with tasklet_setup() to indicate
that we follow the new model.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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It's used in just one place, inline it.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Both qeth and zfcp have fully moved to the polling-driven flow for
Input Queues with commit 0a6e634535f1 ("s390/qdio: extend polling
support to multiple queues") and commit 0b524abc2dd1 ("scsi: zfcp: Lift
Input Queue tasklet from qdio").
So remove the tasklet code for Input Queues, streamline the IRQ handlers
and push the tasklet struct into struct qdio_output_q.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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A master key change on a CCA card may cause an immediately
following request to derive an protected key from a secure
key to fail with error condition 8/2290. The recommendation
from firmware is to retry with 1 second sleep.
So now the low level cca functions return -EAGAIN when this
error condition is seen and the paes retry function will
evaluate the return value. Seeing EAGAIN and running in
process context results in trying to sleep for 1 s now.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Checking zdev->zbus for NULL in __zpci_event_availability() is
superfluous as it can never be NULL at this point. While harmless this
check causes smatch warnings because we later access zdev->zbus with
only having checked zdev != NULL which is sufficient.
The reason zdev->zbus can never be NULL is since with zdev != NULL given
we know the zdev came from get_zdev_by_fid() and thus the zpci_list.
Now on first glance at zpci_create_device() one may assume that there is
a window where the zdev is in the list without a zdev, however this
window can't overlap with __zpci_event_availability() as
zpci_create_device() either runs on the same kthread as part of
availability events, or during the initial CLP List PCI at which point
the __zpci_event_availability() is not yet called as zPCI is not yet
initialized.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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This fixes the following warning:
CHECK linux/arch/s390/kernel/signal.c
linux/arch/s390/kernel/signal.c:465:6: warning: symbol 'arch_do_signal_or_restart' was not declared. Should it be static?
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Rename tape_3590_erp_succeded to tape_3590_erp_succeeded to fix a
spelling mistake in the function name.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20210118113222.71708-1-colin.king@canonical.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Instead of fetching all registers from struct pt_regs and passing
them to the syscall wrappers, let the system call wrappers only
fetch the values really required.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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On s390 asmlinkage is a nop, so remove it.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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This patch converts s390 to use the generic entry infrastructure from
kernel/entry/*.
There are a few special things on s390:
- PIF_PER_TRAP is moved to TIF_PER_TRAP as the generic code doesn't
know about our PIF flags in exit_to_user_mode_loop().
- The old code had several ways to restart syscalls:
a) PIF_SYSCALL_RESTART, which was only set during execve to force a
restart after upgrading a process (usually qemu-kvm) to pgste page
table extensions.
b) PIF_SYSCALL, which is set by do_signal() to indicate that the
current syscall should be restarted. This is changed so that
do_signal() now also uses PIF_SYSCALL_RESTART. Continuing to use
PIF_SYSCALL doesn't work with the generic code, and changing it
to PIF_SYSCALL_RESTART makes PIF_SYSCALL and PIF_SYSCALL_RESTART
more unique.
- On s390 calling sys_sigreturn or sys_rt_sigreturn is implemented by
executing a svc instruction on the process stack which causes a fault.
While handling that fault the fault code sets PIF_SYSCALL to hand over
processing to the syscall code on exit to usermode.
The patch introduces PIF_SYSCALL_RET_SET, which is set if ptrace sets
a return value for a syscall. The s390x ptrace ABI uses r2 both for the
syscall number and return value, so ptrace cannot set the syscall number +
return value at the same time. The flag makes handling that a bit easier.
do_syscall() will just skip executing the syscall if PIF_SYSCALL_RET_SET
is set.
CONFIG_DEBUG_ASCE was removd in favour of the generic CONFIG_DEBUG_ENTRY.
CR1/7/13 will be checked both on kernel entry and exit to contain the
correct asces.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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clang does not know about the 'b1' construct used in bitops inline
assembly. Since the plan is to use compiler atomic builtins anyway
there is no point in requesting clang support for this. Especially if
one considers that the kernel seems to be the only user of this.
With removing this small optimization it is possible to compile the
kernel also with -march=zEC12 and higher using clang.
Build error:
In file included from ./include/linux/bitops.h:32:
./arch/s390/include/asm/bitops.h:69:4: error: invalid operand in inline asm: 'oi $0,${1:b}'
"oi %0,%b1\n"
^
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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With commit f0cbd3b83ed4 ("s390/atomic: circumvent gcc 10 build
regression") there was an attempt to workaroud a gcc build bug,
however with the workaround a similar problem with clang appeared.
It was recommended to use a workaround which would fail again with
gcc. Therefore simply remove the optimization. It is just not worth
the effort.
Besides that all of this will be changed to use compiler atomic
builtins instead anyway.
See https://reviews.llvm.org/D90231
and https://reviews.llvm.org/D91786
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Bypassing the DMA API is bad style, even when we don't expect any
actual problems. Let's utilize the right API helpers for setting the
DMA masks and check for returned errors, so that we benefit from
common sanity checks.
io_subchannel_allocate_dev() required some extra massaging, so that we
can return an errno other than -ENOMEM.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Set the bus type when initializing the cdev structure. The device core
won't act on it until we call device_add().
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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On s390 cleared_pXs flags in struct mmu_gather are set by
corresponding pXd_free_tlb functions. Such approach is
inconsistent with how the generic code interprets these
flags, e.g pte_free_tlb() frees a PTE table - or a PMD
level entity, and so on.
This update does not bring any functional change, since
s390 does not use the flags at the moment.
Fixes: 9de7d833e3708 ("s390/tlb: Convert to generic mmu_gather")
Link: https://lore.kernel.org/lkml/fbb00ac0-9104-8d25-f225-7b3d1b17a01f@huawei.com/
Reported-by: Zhenyu Ye <yezhenyu2@huawei.com>
Suggested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux
Pull perf tools fixes from Arnaldo Carvalho de Melo:
- Fix 'CPU too large' error in Intel PT
- Correct event attribute sizes in 'perf inject'
- Sync build_bug.h and kvm.h kernel copies
- Fix bpf.h header include directive in 5sec.c 'perf trace' bpf example
- libbpf tests fixes
- Fix shadow stat 'perf test' for non-bash shells
- Take cgroups into account for shadow stats in 'perf stat'
* tag 'perf-tools-fixes-2021-01-17' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
perf inject: Correct event attribute sizes
perf intel-pt: Fix 'CPU too large' error
perf stat: Take cgroups into account for shadow stats
perf stat: Introduce struct runtime_stat_data
libperf tests: Fail when failing to get a tracepoint id
libperf tests: If a test fails return non-zero
libperf tests: Avoid uninitialized variable warning
perf test: Fix shadow stat test for non-bash shells
tools headers: Syncronize linux/build_bug.h with the kernel sources
tools headers UAPI: Sync kvm.h headers with the kernel sources
perf bpf examples: Fix bpf.h header include directive in 5sec.c example
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"One fix for a lack of alignment in our linker script, that can lead to
crashes depending on configuration etc.
One fix for the 32-bit VDSO after the C VDSO conversion.
Thanks to Andreas Schwab, Ariel Marcovitch, and Christophe Leroy"
* tag 'powerpc-5.11-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/vdso: Fix clock_gettime_fallback for vdso32
powerpc: Fix alignment bug within the init sections
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Pull misc vfs fixes from Al Viro:
"Several assorted fixes.
I still think that audit ->d_name race is better fixed this way for
the benefit of backports, with any possibly fancier variants done on
top of it"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
dump_common_audit_data(): fix racy accesses to ->d_name
iov_iter: fix the uaccess area in copy_compat_iovec_from_user
umount(2): move the flag validity checks first
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So technically there is nothing wrong with adding a pinned page to the
swap cache, but the pinning obviously means that the page can't actually
be free'd right now anyway, so it's a bit pointless.
However, the real problem is not with it being a bit pointless: the real
issue is that after we've added it to the swap cache, we'll try to unmap
the page. That will succeed, because the code in mm/rmap.c doesn't know
or care about pinned pages.
Even the unmapping isn't fatal per se, since the page will stay around
in memory due to the pinning, and we do hold the connection to it using
the swap cache. But when we then touch it next and take a page fault,
the logic in do_swap_page() will map it back into the process as a
possibly read-only page, and we'll then break the page association on
the next COW fault.
Honestly, this issue could have been fixed in any of those other places:
(a) we could refuse to unmap a pinned page (which makes conceptual
sense), or (b) we could make sure to re-map a pinned page writably in
do_swap_page(), or (c) we could just make do_wp_page() not COW the
pinned page (which was what we historically did before that "mm:
do_wp_page() simplification" commit).
But while all of them are equally valid models for breaking this chain,
not putting pinned pages into the swap cache in the first place is the
simplest one by far.
It's also the safest one: the reason why do_wp_page() was changed in the
first place was that getting the "can I re-use this page" wrong is so
fraught with errors. If you do it wrong, you end up with an incorrectly
shared page.
As a result, using "page_maybe_dma_pinned()" in either do_wp_page() or
do_swap_page() would be a serious bug since it is only a (very good)
heuristic. Re-using the page requires a hard black-and-white rule with
no room for ambiguity.
In contrast, saying "this page is very likely dma pinned, so let's not
add it to the swap cache and try to unmap it" is an obviously safe thing
to do, and if the heuristic might very rarely be a false positive, no
harm is done.
Fixes: 09854ba94c6a ("mm: do_wp_page() simplification")
Reported-and-tested-by: Martin Raiber <martin@urbackup.org>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"Nine minor fixes, seven in drivers and two in the core SCSI disk
driver (sd) which should be harmless involving removing an unused
variable and quietening a spurious warning"
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: sd: Remove obsolete variable in sd_remove()
scsi: sd: Suppress spurious errors when WRITE SAME is being disabled
scsi: scsi_debug: Fix memleak in scsi_debug_init()
scsi: mpt3sas: Fix spelling mistake in Kconfig "compatiblity" -> "compatibility"
scsi: qedi: Correct max length of CHAP secret
scsi: ufs: Correct the LUN used in eh_device_reset_handler() callback
scsi: ufs: Relocate flush of exceptional event
scsi: ufs: Relax the condition of UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL
scsi: ufs: Fix possible power drain during system suspend
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We are not guaranteed the locking environment that would prevent
dentry getting renamed right under us. And it's possible for
old long name to be freed after rename, leading to UAF here.
Cc: stable@kernel.org # v2.6.2+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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