- 23 Oct, 2019 31 commits
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Arnd Bergmann authored
There are two code locations that implement the SG_IO ioctl: the old sg.c driver, and the generic scsi_ioctl helper that is in turn used by multiple drivers. To eradicate the old compat_ioctl conversion handler for the SG_IO command, I implement a readable pair of put_sg_io_hdr() /get_sg_io_hdr() helper functions that can be used for both compat and native mode, and then I call this from both drivers. For the iovec handling, there is already a compat_import_iovec() function that can simply be called in place of import_iovec(). To avoid having to pass the compat/native state through multiple indirections, I mark the SG_IO command itself as compatible in fs/compat_ioctl.c and use in_compat_syscall() to figure out where we are called from. As a side-effect of this, the sg.c driver now also accepts the 32-bit sg_io_hdr format in compat mode using the read/write interface, not just ioctl. This should improve compatiblity with old 32-bit binaries, but it would break if any application intentionally passes the 64-bit data structure in compat mode here. Steffen Maier helped debug an issue in an earlier version of this patch. Cc: Steffen Maier <maier@linux.ibm.com> Cc: linux-scsi@vger.kernel.org Cc: Doug Gilbert <dgilbert@interlog.com> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Signed-off-by:Arnd Bergmann <arnd@arndb.de>
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Arnd Bergmann authored
All watchdog drivers implement the same set of ioctl commands, and fortunately all of them are compatible between 32-bit and 64-bit architectures. Modern drivers always go through drivers/watchdog/wdt.c as an abstraction layer, but older ones implement their own file_operations on a character device for this. Move the handling from fs/compat_ioctl.c into the individual drivers. Note that most of the legacy drivers will never be used on 64-bit hardware, because they are for an old 32-bit SoC implementation, but doing them all at once is safer than trying to guess which ones do or do not need the compat_ioctl handling. Reviewed-by:
Guenter Roeck <linux@roeck-us.net> Signed-off-by:
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Arnd Bergmann authored
Remove the special case for FITRIM, and make file systems handle that like all other ioctl commands with their own handlers. Cc: linux-ext4@vger.kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> Cc: linux-nilfs@vger.kernel.org Cc: ocfs2-devel@oss.oracle.com Signed-off-by: -
Arnd Bergmann authored
Out of the four ioctl commands supported on gfs2, only FITRIM works in compat mode. Add a proper handler based on the ext4 implementation. Fixes: 6ddc5c3d ("gfs2: getlabel support") Reviewed-by:
Bob Peterson <rpeterso@redhat.com> Cc: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by:
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Arnd Bergmann authored
The last users are all gone, so let's remove the macro as well. Signed-off-by: -
Arnd Bergmann authored
Commit aa98aa31 ("md: move compat_ioctl handling into md.c") already removed the COMPATIBLE_IOCTL() table entries and added a complete implementation, but a few lines got left behind and should also be removed here. Cc: linux-raid@vger.kernel.org Cc: Song Liu <song@kernel.org> Signed-off-by:
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Arnd Bergmann authored
The /dev/rawX implementation already handles these just fine, so the entries in the table are not needed any more. Signed-off-by: -
Arnd Bergmann authored
The /proc/pci/ implementation already handles these just fine, so the entries in the table are not needed any more. Cc: linux-pci@vger.kernel.org Cc: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: -
Arnd Bergmann authored
The joystick driver already handles these just fine, so the entries in the table are not needed any more. Cc: linux-input@vger.kernel.org Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: -
Arnd Bergmann authored
These are all handled by the random driver, so instead of listing each ioctl, we can use the generic compat_ptr_ioctl() helper. Acked-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
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Arnd Bergmann authored
Since commit 07d106d0 ("vfs: fix up ENOIOCTLCMD error handling"), we don't warn about unhandled compat-ioctl command code any more, but just return the same error that a native file descriptor returns when there is no handler. This means the IGNORE_IOCTL() annotations are completely useless and can all be removed. TIOCSTART/TIOCSTOP and KDGHWCLK/KDSHWCLK fall into the same category, but for some reason were listed as COMPATIBLE_IOCTL(). Signed-off-by:
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Arnd Bergmann authored
The SNDCTL_* and SOUND_* commands are the old OSS user interface. I checked all the sound ioctl commands listed in fs/compat_ioctl.c to see if we still need the translation handlers. Here is what I found: - sound/oss/ is (almost) gone from the kernel, this is what actually needed all the translations - The ALSA emulation for OSS correctly handles all compat_ioctl commands already. - sound/oss/dmasound/ is the last holdout of the original OSS code, this is only used on arch/m68k, which has no 64-bit mode and hence needs no compat handlers - arch/um/drivers/hostaudio_kern.c may run in 64-bit mode with 32-bit x86 user space underneath it. This rare corner case is the only one that still needs the compat handlers. By adding a simple redirect of .compat_ioctl to .unlocked_ioctl in the UML driver, we can remove all the COMPATIBLE_IOCTL() annotations without a change in functionality. For completeness, I'm adding the same thing to the dmasound file, knowing that it makes no difference. The compat_ioctl list contains one comment about SNDCTL_DSP_MAPINBUF and SNDCTL_DSP_MAPOUTBUF, which actually would need a translation handler if implemented. However, the native implementation just returns -EINVAL, so we don't care. Reviewed-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
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Arnd Bergmann authored
The two drivers implementing these both gained proper compat_ioctl() handlers a long time ago with commits bb6c8d8f ("HID: hiddev: Add 32bit ioctl compatibilty") and ae5e49c7 ("HID: hidraw: add compatibility ioctl() for 32-bit applications."), so the lists in fs/compat_ioctl.c are no longer used. It appears that the lists were also incomplete, so the translation didn't actually work correctly when it was still in use. Remove them as cleanup. Cc: linux-bluetooth@vger.kernel.org Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Signed-off-by:
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Arnd Bergmann authored
As of commit f0193d3e ("change semantics of ldisc ->compat_ioctl()"), all hciuart ioctl commands are handled correctly in the driver, and we never need to go through the table here. Cc: linux-bluetooth@vger.kernel.org Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Signed-off-by:
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Arnd Bergmann authored
All these ioctl commands are compatible, so we can handle them with a trivial wrapper in hci_sock.c and remove the listing in fs/compat_ioctl.c. A few of the commands pass integer arguments instead of pointers, so for correctness skip the compat_ptr() conversion here. Acked-by:
Marcel Holtmann <marcel@holtmann.org> Signed-off-by:
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Arnd Bergmann authored
All these ioctl commands are compatible, so we can handle them with a trivial wrapper in rfcomm/sock.c and remove the listing in fs/compat_ioctl.c. Acked-by:
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Arnd Bergmann authored
Neither the old isdn4linux interface nor the newer mISDN stack ever had working 32-bit compat mode as far as I can tell. However, the CAPI stack has some ioctl commands that are correctly listed in fs/compat_ioctl.c. We can trivially move all of those into the corresponding file that implement the native handlers by adding a compat_ioctl redirect to that. I did notice that treating CAPI_MANUFACTURER_CMD() as compatible is broken, so I'm also adding a handler for that, realizing that in all likelyhood, nobody is ever going to call it. Cc: Karsten Keil <isdn@linux-pingi.de> Cc: netdev@vger.kernel.org Cc: isdn4linux@listserv.isdn4linux.de Signed-off-by: -
Arnd Bergmann authored
These are two obscure ioctl commands, in a driver that only has compatible commands, so just let the driver handle this itself. Acked-by:
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by:
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Arnd Bergmann authored
MTIOCPOS and MTIOCGET are incompatible between 32-bit and 64-bit user space, and traditionally have been translated in fs/compat_ioctl.c. To get rid of that translation handler, move a corresponding implementation into each of the four drivers implementing those commands. The interesting part of that is now in a new linux/mtio.h header that wraps the existing uapi/linux/mtio.h header and provides an abstraction to let drivers handle both cases easily. Using an in_compat_syscall() check, the caller does not have to keep track of whether this was called through .unlocked_ioctl() or .compat_ioctl(). Acked-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "Kai Mäkisara" <Kai.Makisara@kolumbus.fi> Cc: linux-scsi@vger.kernel.org Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by:
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Arnd Bergmann authored
A handful of drivers all have a trivial wrapper around their ioctl handler, but don't call the compat_ptr() conversion function at the moment. In practice this does not matter, since none of them are used on the s390 architecture and for all other architectures, compat_ptr() does not do anything, but using the new compat_ptr_ioctl() helper makes it more correct in theory, and simplifies the code. I checked that all ioctl handlers in these files are compatible and take either pointer arguments or no argument. Acked-by:
Al Viro <viro@zeniv.linux.org.uk> Acked-by:
Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by:
Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by:
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Arnd Bergmann authored
The .ioctl and .compat_ioctl file operations have the same prototype so they can both point to the same function, which works great almost all the time when all the commands are compatible. One exception is the s390 architecture, where a compat pointer is only 31 bit wide, and converting it into a 64-bit pointer requires calling compat_ptr(). Most drivers here will never run in s390, but since we now have a generic helper for it, it's easy enough to use it consistently. I double-checked all these drivers to ensure that all ioctl arguments are used as pointers or are ignored, but are not interpreted as integer values. Acked-by:
Jason Gunthorpe <jgg@mellanox.com> Acked-by:
Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by:
Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by:
David Sterba <dsterba@suse.com> Acked-by:
Darren Hart (VMware) <dvhart@infradead.org> Acked-by:
Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by:
Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by:
Dan Williams <dan.j.williams@intel.com> Signed-off-by:
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Arnd Bergmann authored
Each of these drivers has a copy of the same trivial helper function to convert the pointer argument and then call the native ioctl handler. We now have a generic implementation of that, so use it. Acked-by:
Michael S. Tsirkin <mst@redhat.com> Acked-by:
David S. Miller <davem@davemloft.net> Acked-by:
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by:
Jiri Kosina <jkosina@suse.cz> Reviewed-by:
Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by:
Cornelia Huck <cohuck@redhat.com> Signed-off-by:
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Arnd Bergmann authored
We no longer need the rtc compat handling to be in common code, now that all drivers are either moved to the rtc-class framework, or (rarely) exist in drivers/char for architectures without compat mode (m68k, alpha and ia64, respectively). I checked the list of ioctl commands in drivers, and the ones that are not already handled are all compatible, again with the one exception of m68k driver, which implements RTC_PLL_GET and RTC_PLL_SET, but has no compat mode. Unlike earlier versions of this patch, I'm now adding a separate compat_ioctl handler that takes care of RTC_IRQP_READ32/RTC_IRQP_SET32 and treats all other commands as compatible, leaving the native behavior unchanged. The old conversion handler also deals with RTC_EPOCH_READ and RTC_EPOCH_SET, which are not handled in rtc-dev.c but only in a single device driver (rtc-vr41xx), so I'm adding the compat version in the same place. I don't expect other drivers to need those commands in the future. Acked-by:
Alexandre Belloni <alexandre.belloni@bootlin.com> Reviewed-by:
Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by:
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Arnd Bergmann authored
The ceph_ioctl function is used both for files and directories, but only the files support doing that in 32-bit compat mode. On the s390 architecture, there is also a problem with invalid 31-bit pointers that need to be passed through compat_ptr(). Use the new compat_ptr_ioctl() to address both issues. Note: When backporting this patch to stable kernels, "compat_ioctl: add compat_ptr_ioctl()" is needed as well. Reviewed-by:
"Yan, Zheng" <zyan@redhat.com> Cc: stable@vger.kernel.org Signed-off-by:
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Al Viro authored
Handle ioctls that might be handled without reaching ->ioctl() in native case on the top level there. The counterpart of vfs_ioctl() (i.e. calling ->unlock_ioctl(), etc.) left as-is; eventually that would turn simply into the call of ->compat_ioctl(), but that'll take more work. Once that is done, we can move the remains of compat_sys_ioctl() into fs/ioctl.c and finally bury fs/compat_ioctl.c. Signed-off-by:
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Al Viro authored
... and lose the ridiculous games with compat_alloc_user_space() there. Signed-off-by:
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Al Viro authored
casting to pointer to int, only to pass that to function that takes pointer to void and uses it as pointer to structure is really asking for trouble. "Some pointer, I'm not sure what to" is spelled "void *", not "int *"; use that. And declare the functions we are passing that pointer to as taking the pointer to what they really want to access. Signed-off-by:
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Al Viro authored
... and hadn't for a long time. Signed-off-by:
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Al Viro authored
it takes a pointer argument, regular file or no regular file Signed-off-by:
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Al Viro authored
Unlike FICLONE, all of those take a pointer argument; they do need compat_ptr() applied to arg. Fixes: d79bdd52 ("vfs: wire up compat ioctl for CLONE/CLONE_RANGE") Fixes: 54dbc151 ("vfs: hoist the btrfs deduplication ioctl to the vfs") Fixes: ceac204e ("fs: make fiemap work from compat_ioctl") Signed-off-by:
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Arnd Bergmann authored
Many drivers have ioctl() handlers that are completely compatible between 32-bit and 64-bit architectures, except for the argument that is passed down from user space and may have to be passed through compat_ptr() in order to become a valid 64-bit pointer. Using ".compat_ptr = compat_ptr_ioctl" in file operations should let us simplify a lot of those drivers to avoid #ifdef checks, and convert additional drivers that don't have proper compat handling yet. On most architectures, the compat_ptr_ioctl() just passes all arguments to the corresponding ->ioctl handler. The exception is arch/s390, where compat_ptr() clears the top bit of a 32-bit pointer value, so user space pointers to the second 2GB alias the first 2GB, as is the case for native 32-bit s390 user space. The compat_ptr_ioctl() function must therefore be used only with ioctl functions that either ignore the argument or pass a pointer to a compatible data type. If any ioctl command handled by fops->unlocked_ioctl passes a plain integer instead of a pointer, or any of the passed data types is incompatible between 32-bit and 64-bit architectures, a proper handler is required instead of compat_ptr_ioctl. Signed-off-by:
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- 06 Oct, 2019 4 commits
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Linus Torvalds authored
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Linus Torvalds authored
In commit 4ed28639 ("fs, elf: drop MAP_FIXED usage from elf_map") we changed elf to use MAP_FIXED_NOREPLACE instead of MAP_FIXED for the executable mappings. Then, people reported that it broke some binaries that had overlapping segments from the same file, and commit ad55eac7 ("elf: enforce MAP_FIXED on overlaying elf segments") re-instated MAP_FIXED for some overlaying elf segment cases. But only some - despite the summary line of that commit, it only did it when it also does a temporary brk vma for one obvious overlapping case. Now Russell King reports another overlapping case with old 32-bit x86 binaries, which doesn't trigger that limited case. End result: we had better just drop MAP_FIXED_NOREPLACE entirely, and go back to MAP_FIXED. Yes, it's a sign of old binaries generated with old tool-chains, but we do pride ourselves on not breaking existing setups. This still leaves MAP_FIXED_NOREPLACE in place for the load_elf_interp() and the old load_elf_library() use-cases, because nobody has reported breakage for those. Yet. Note that in all the cases seen so far, the overlapping elf sections seem to be just re-mapping of the same executable with different section attributes. We could possibly introduce a new MAP_FIXED_NOFILECHANGE flag or similar, which acts like NOREPLACE, but allows just remapping the same executable file using different protection flags. It's not clear that would make a huge difference to anything, but if people really hate that "elf remaps over previous maps" behavior, maybe at least a more limited form of remapping would alleviate some concerns. Alternatively, we should take a look at our elf_map() logic to see if we end up not mapping things properly the first time. In the meantime, this is the minimal "don't do that then" patch while people hopefully think about it more. Reported-by:
Russell King <linux@armlinux.org.uk> Fixes: 4ed28639 ("fs, elf: drop MAP_FIXED usage from elf_map") Fixes: ad55eac7 ("elf: enforce MAP_FIXED on overlaying elf segments") Cc: Michal Hocko <mhocko@suse.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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git://git.infradead.org/users/hch/dma-mappingLinus Torvalds authored
Pull dma-mapping regression fix from Christoph Hellwig: "Revert an incorret hunk from a patch that caused problems on various arm boards (Andrey Smirnov)" * tag 'dma-mapping-5.4-1' of git://git.infradead.org/users/hch/dma-mapping: dma-mapping: fix false positive warnings in dma_common_free_remap()
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git://git.kernel.org/pub/scm/linux/kernel/git/soc/socLinus Torvalds authored
Pull ARM SoC fixes from Olof Johansson: "A few fixes this time around: - Fixup of some clock specifications for DRA7 (device-tree fix) - Removal of some dead/legacy CPU OPP/PM code for OMAP that throws warnings at boot - A few more minor fixups for OMAPs, most around display - Enable STM32 QSPI as =y since their rootfs sometimes comes from there - Switch CONFIG_REMOTEPROC to =y since it went from tristate to bool - Fix of thermal zone definition for ux500 (5.4 regression)" * tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: ARM: multi_v7_defconfig: Fix SPI_STM32_QSPI support ARM: dts: ux500: Fix up the CPU thermal zone arm64/ARM: configs: Change CONFIG_REMOTEPROC from m to y ARM: dts: am4372: Set memory bandwidth limit for DISPC ARM: OMAP2+: Fix warnings with broken omap2_set_init_voltage() ARM: OMAP2+: Add missing LCDC midlemode for am335x ARM: OMAP2+: Fix missing reset done flag for am3 and am43 ARM: dts: Fix gpio0 flags for am335x-icev2 ARM: omap2plus_defconfig: Enable more droid4 devices as loadable modules ARM: omap2plus_defconfig: Enable DRM_TI_TFP410 DTS: ARM: gta04: introduce legacy spi-cs-high to make display work again ARM: dts: Fix wrong clocks for dra7 mcasp clk: ti: dra7: Fix mcasp8 clock bits
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- 05 Oct, 2019 5 commits
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Linus Torvalds authored
Merge tag 'kbuild-fixes-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - remove unneeded ar-option and KBUILD_ARFLAGS - remove long-deprecated SUBDIRS - fix modpost to suppress false-positive warnings for UML builds - fix namespace.pl to handle relative paths to ${objtree}, ${srctree} - make setlocalversion work for /bin/sh - make header archive reproducible - fix some Makefiles and documents * tag 'kbuild-fixes-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kheaders: make headers archive reproducible kbuild: update compile-test header list for v5.4-rc2 kbuild: two minor updates for Documentation/kbuild/modules.rst scripts/setlocalversion: clear local variable to make it work for sh namespace: fix namespace.pl script to support relative paths video/logo: do not generate unneeded logo C files video/logo: remove unneeded *.o pattern from clean-files integrity: remove pointless subdir-$(CONFIG_...) integrity: remove unneeded, broken attempt to add -fshort-wchar modpost: fix static EXPORT_SYMBOL warnings for UML build kbuild: correct formatting of header in kbuild module docs kbuild: remove SUBDIRS support kbuild: remove ar-option and KBUILD_ARFLAGS
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds authored
Pull SCSI fixes from James Bottomley: "Twelve patches mostly small but obvious fixes or cosmetic but small updates" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: qla2xxx: Fix Nport ID display value scsi: qla2xxx: Fix N2N link up fail scsi: qla2xxx: Fix N2N link reset scsi: qla2xxx: Optimize NPIV tear down process scsi: qla2xxx: Fix stale mem access on driver unload scsi: qla2xxx: Fix unbound sleep in fcport delete path. scsi: qla2xxx: Silence fwdump template message scsi: hisi_sas: Make three functions static scsi: megaraid: disable device when probe failed after enabled device scsi: storvsc: setup 1:1 mapping between hardware queue and CPU queue scsi: qedf: Remove always false 'tmp_prio < 0' statement scsi: ufs: skip shutdown if hba is not powered scsi: bnx2fc: Handle scope bits when array returns BUSY or TSF
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Linus Torvalds authored
This makes getdents() and getdents64() do sanity checking on the pathname that it gives to user space. And to mitigate the performance impact of that, it first cleans up the way it does the user copying, so that the code avoids doing the SMAP/PAN updates between each part of the dirent structure write. I really wanted to do this during the merge window, but didn't have time. The conversion of filldir to unsafe_put_user() is something I've had around for years now in a private branch, but the extra pathname checking finally made me clean it up to the point where it is mergable. It's worth noting that the filename validity checking really should be a bit smarter: it would be much better to delay the error reporting until the end of the readdir, so that non-corrupted filenames are still returned. But that involves bigger changes, so let's see if anybody actually hits the corrupt directory entry case before worrying about it further. * branch 'readdir': Make filldir[64]() verify the directory entry filename is valid Convert filldir[64]() from __put_user() to unsafe_put_user()
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Linus Torvalds authored
This has been discussed several times, and now filesystem people are talking about doing it individually at the filesystem layer, so head that off at the pass and just do it in getdents{64}(). This is partially based on a patch by Jann Horn, but checks for NUL bytes as well, and somewhat simplified. There's also commentary about how it might be better if invalid names due to filesystem corruption don't cause an immediate failure, but only an error at the end of the readdir(), so that people can still see the filenames that are ok. There's also been discussion about just how much POSIX strictly speaking requires this since it's about filesystem corruption. It's really more "protect user space from bad behavior" as pointed out by Jann. But since Eric Biederman looked up the POSIX wording, here it is for context: "From readdir: The readdir() function shall return a pointer to a structure representing the directory entry at the current position in the directory stream specified by the argument dirp, and position the directory stream at the next entry. It shall return a null pointer upon reaching the end of the directory stream. The structure dirent defined in the <dirent.h> header describes a directory entry. From definitions: 3.129 Directory Entry (or Link) An object that associates a filename with a file. Several directory entries can associate names with the same file. ... 3.169 Filename A name consisting of 1 to {NAME_MAX} bytes used to name a file. The characters composing the name may be selected from the set of all character values excluding the slash character and the null byte. The filenames dot and dot-dot have special meaning. A filename is sometimes referred to as a 'pathname component'." Note that I didn't bother adding the checks to any legacy interfaces that nobody uses. Also note that if this ends up being noticeable as a performance regression, we can fix that to do a much more optimized model that checks for both NUL and '/' at the same time one word at a time. We haven't really tended to optimize 'memchr()', and it only checks for one pattern at a time anyway, and we really _should_ check for NUL too (but see the comment about "soft errors" in the code about why it currently only checks for '/') See the CONFIG_DCACHE_WORD_ACCESS case of hash_name() for how the name lookup code looks for pathname terminating characters in parallel. Link: https://lore.kernel.org/lkml/20190118161440.220134-2-jannh@google.com/ Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jann Horn <jannh@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: -
Linus Torvalds authored
We really should avoid the "__{get,put}_user()" functions entirely, because they can easily be mis-used and the original intent of being used for simple direct user accesses no longer holds in a post-SMAP/PAN world. Manually optimizing away the user access range check makes no sense any more, when the range check is generally much cheaper than the "enable user accesses" code that the __{get,put}_user() functions still need. So instead of __put_user(), use the unsafe_put_user() interface with user_access_{begin,end}() that really does generate better code these days, and which is generally a nicer interface. Under some loads, the multiple user writes that filldir() does are actually quite noticeable. This also makes the dirent name copy use unsafe_put_user() with a couple of macros. We do not want to make function calls with SMAP/PAN disabled, and the code this generates is quite good when the architecture uses "asm goto" for unsafe_put_user() like x86 does. Note that this doesn't bother with the legacy cases. Nobody should use them anyway, so performance doesn't really matter there. Signed-off-by:
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