80fa5d604d
962 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
6fbd6cf85a |
Kbuild updates for v5.12
- Fix false-positive build warnings for ARCH=ia64 builds
- Optimize dictionary size for module compression with xz
- Check the compiler and linker versions in Kconfig
- Fix misuse of extra-y
- Support DWARF v5 debug info
- Clamp SUBLEVEL to 255 because stable releases 4.4.x and 4.9.x
exceeded the limit
- Add generic syscall{tbl,hdr}.sh for cleanups across arches
- Minor cleanups of genksyms
- Minor cleanups of Kconfig
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Merge tag 'kbuild-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Fix false-positive build warnings for ARCH=ia64 builds
- Optimize dictionary size for module compression with xz
- Check the compiler and linker versions in Kconfig
- Fix misuse of extra-y
- Support DWARF v5 debug info
- Clamp SUBLEVEL to 255 because stable releases 4.4.x and 4.9.x
exceeded the limit
- Add generic syscall{tbl,hdr}.sh for cleanups across arches
- Minor cleanups of genksyms
- Minor cleanups of Kconfig
* tag 'kbuild-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (38 commits)
initramfs: Remove redundant dependency of RD_ZSTD on BLK_DEV_INITRD
kbuild: remove deprecated 'always' and 'hostprogs-y/m'
kbuild: parse C= and M= before changing the working directory
kbuild: reuse this-makefile to define abs_srctree
kconfig: unify rule of config, menuconfig, nconfig, gconfig, xconfig
kconfig: omit --oldaskconfig option for 'make config'
kconfig: fix 'invalid option' for help option
kconfig: remove dead code in conf_askvalue()
kconfig: clean up nested if-conditionals in check_conf()
kconfig: Remove duplicate call to sym_get_string_value()
Makefile: Remove # characters from compiler string
Makefile: reuse CC_VERSION_TEXT
kbuild: check the minimum linker version in Kconfig
kbuild: remove ld-version macro
scripts: add generic syscallhdr.sh
scripts: add generic syscalltbl.sh
arch: syscalls: remove $(srctree)/ prefix from syscall tables
arch: syscalls: add missing FORCE and fix 'targets' to make if_changed work
gen_compile_commands: prune some directories
kbuild: simplify access to the kernel's version
...
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Linus Torvalds
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29c395c77a |
Rework of the X86 irq stack handling:
The irq stack switching was moved out of the ASM entry code in course of
the entry code consolidation. It ended up being suboptimal in various
ways.
- Make the stack switching inline so the stackpointer manipulation is not
longer at an easy to find place.
- Get rid of the unnecessary indirect call.
- Avoid the double stack switching in interrupt return and reuse the
interrupt stack for softirq handling.
- A objtool fix for CONFIG_FRAME_POINTER=y builds where it got confused
about the stack pointer manipulation.
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Merge tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 irq entry updates from Thomas Gleixner:
"The irq stack switching was moved out of the ASM entry code in course
of the entry code consolidation. It ended up being suboptimal in
various ways.
This reworks the X86 irq stack handling:
- Make the stack switching inline so the stackpointer manipulation is
not longer at an easy to find place.
- Get rid of the unnecessary indirect call.
- Avoid the double stack switching in interrupt return and reuse the
interrupt stack for softirq handling.
- A objtool fix for CONFIG_FRAME_POINTER=y builds where it got
confused about the stack pointer manipulation"
* tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Fix stack-swizzle for FRAME_POINTER=y
um: Enforce the usage of asm-generic/softirq_stack.h
x86/softirq/64: Inline do_softirq_own_stack()
softirq: Move do_softirq_own_stack() to generic asm header
softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig
x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
x86/softirq: Remove indirection in do_softirq_own_stack()
x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall
x86/entry: Convert device interrupts to inline stack switching
x86/entry: Convert system vectors to irq stack macro
x86/irq: Provide macro for inlining irq stack switching
x86/apic: Split out spurious handling code
x86/irq/64: Adjust the per CPU irq stack pointer by 8
x86/irq: Sanitize irq stack tracking
x86/entry: Fix instrumentation annotation
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Linus Torvalds
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414eece95b |
clang-lto for v5.12-rc1 (part2)
- Generate __mcount_loc in objtool (Peter Zijlstra) - Support running objtool against vmlinux.o (Sami Tolvanen) - Clang LTO enablement for x86 (Sami Tolvanen) -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmA1fn8ACgkQiXL039xt wCbswQ//Zmnq912Ubyn5uPe9SOS/kumGDoqtxGzlZwo/pSB3qFArhD6G07sJ49XD nu/05ZcOda760wubnhcuK91n2fY5i/eGLXMSjfgtdVcco4Q67nPQydc+LGdhuDco FlhL8TAIwqYN1f2nJK1IggZpZFxz5r/r1Pq8q1S0oQRqDenxDBQwNtBba4B1OIxw /FE/1Hp3xwRnuJEP2jREBeY1yQ+Y1n859pZcDgSOWlTArcp8EVUi5hIWJ9DwIe73 mqnx6PcFWEYB0zLNZmZz2gpEac+ncGyme6ChayeuQfInbL5dhx97jFGt3S6/+NSY mF2zyaR/+JsGGuM8dVqH3izKCJXCEAGirrdMO1ndb9HdwS3KnYEiag2ciNWL0wm3 UEM4r0i2B14sU3pkyotKgsJdOSgorMKkQUPb2wW+OUfnkZNEWKLqylMgNXBD80l4 WG5vYQRwwFN9jRBik6Z5YFGnwGsNIoGg1F1GRNMjh6h51adYQeBN/1QJE1FJ5L4D iKzmZYqimKUINXWfI6TNyqiv9TctOt65pxnRyq+MHxfTDzHGyc3MUeCeCiR1a1yI S5QhcgfSnC/NjDA0+oYC6yRlcBtfhjtUqFTGoZ4q4q/LF1BVU1bPyIXZrROLc05s LNMMBcWbJetJxFtm/gYfiVFuNitYtxbBV1krVtsWznCA2nKGJ9w= =htKJ -----END PGP SIGNATURE----- Merge tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull more clang LTO updates from Kees Cook: "Clang LTO x86 enablement. Full disclosure: while this has _not_ been in linux-next (since it initially looked like the objtool dependencies weren't going to make v5.12), it has been under daily build and runtime testing by Sami for quite some time. These x86 portions have been discussed on lkml, with Peter, Josh, and others helping nail things down. The bulk of the changes are to get objtool working happily. The rest of the x86 enablement is very small. Summary: - Generate __mcount_loc in objtool (Peter Zijlstra) - Support running objtool against vmlinux.o (Sami Tolvanen) - Clang LTO enablement for x86 (Sami Tolvanen)" Link: https://lore.kernel.org/lkml/20201013003203.4168817-26-samitolvanen@google.com/ Link: https://lore.kernel.org/lkml/cover.1611263461.git.jpoimboe@redhat.com/ * tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: kbuild: lto: force rebuilds when switching CONFIG_LTO x86, build: allow LTO to be selected x86, cpu: disable LTO for cpu.c x86, vdso: disable LTO only for vDSO kbuild: lto: postpone objtool objtool: Split noinstr validation from --vmlinux x86, build: use objtool mcount tracing: add support for objtool mcount objtool: Don't autodetect vmlinux.o objtool: Fix __mcount_loc generation with Clang's assembler objtool: Add a pass for generating __mcount_loc |
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Linus Torvalds
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7d6beb71da |
idmapped-mounts-v5.12
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Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf
https://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
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Sami Tolvanen
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e242db40be |
x86, vdso: disable LTO only for vDSO
Disable LTO for the vDSO. Note that while we could use Clang's LTO for the 64-bit vDSO, it won't add noticeable benefit for the small amount of C code. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> |
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Masahiro Yamada
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29c5c3ac63 |
arch: syscalls: remove $(srctree)/ prefix from syscall tables
The 'syscall' variables are not directly used in the commands. Remove the $(srctree)/ prefix because we can rely on VPATH. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> |
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Masahiro Yamada
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865fa29f7d |
arch: syscalls: add missing FORCE and fix 'targets' to make if_changed work
The rules in these Makefiles cannot detect the command line change because the prerequisite 'FORCE' is missing. Adding 'FORCE' will result in the headers being rebuilt every time because the 'targets' additions are also wrong; the file paths in 'targets' must be relative to the current Makefile. Fix all of them so the if_changed rules work correctly. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> |
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Ingo Molnar
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a3251c1a36 |
Merge branch 'x86/paravirt' into x86/entry
Merge in the recent paravirt changes to resolve conflicts caused by objtool annotations. Conflicts: arch/x86/xen/xen-asm.S Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Thomas Gleixner
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52d743f3b7 |
x86/softirq: Remove indirection in do_softirq_own_stack()
Use the new inline stack switching and remove the old ASM indirect call implementation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210210002512.972714001@linutronix.de |
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Thomas Gleixner
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359f01d181 |
x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall
To avoid yet another macro implementation reuse the existing run_sysvec_on_irqstack_cond() and move the set_irq_regs() handling into the called function. Makes the code even simpler. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210210002512.869753106@linutronix.de |
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Thomas Gleixner
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5b51e1db9b |
x86/entry: Convert device interrupts to inline stack switching
Convert device interrupts to inline stack switching by replacing the existing macro implementation with the new inline version. Tweak the function signature of the actual handler function to have the vector argument as u32. That allows the inline macro to avoid extra intermediates and lets the compiler be smarter about the whole thing. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210210002512.769728139@linutronix.de |
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Thomas Gleixner
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569dd8b4eb |
x86/entry: Convert system vectors to irq stack macro
To inline the stack switching and to prepare for enabling CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK provide a macro template for system vectors and device interrupts and convert the system vectors over to it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210210002512.676197354@linutronix.de |
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Thomas Gleixner
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15f720aabe |
x86/entry: Fix instrumentation annotation
Embracing a callout into instrumentation_begin() / instrumentation_begin()
does not really make sense. Make the latter instrumentation_end().
Fixes:
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Juergen Gross
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afd30525a6 |
x86/xen: Drop USERGS_SYSRET64 paravirt call
USERGS_SYSRET64 is used to return from a syscall via SYSRET, but a Xen PV guest will nevertheless use the IRET hypercall, as there is no sysret PV hypercall defined. So instead of testing all the prerequisites for doing a sysret and then mangling the stack for Xen PV again for doing an iret just use the iret exit from the beginning. This can easily be done via an ALTERNATIVE like it is done for the sysenter compat case already. It should be noted that this drops the optimization in Xen for not restoring a few registers when returning to user mode, but it seems as if the saved instructions in the kernel more than compensate for this drop (a kernel build in a Xen PV guest was slightly faster with this patch applied). While at it remove the stale sysret32 remnants. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210120135555.32594-6-jgross@suse.com |
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Juergen Gross
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53c9d92409 |
x86/pv: Switch SWAPGS to ALTERNATIVE
SWAPGS is used only for interrupts coming from user mode or for returning to user mode. So there is no reason to use the PARAVIRT framework, as it can easily be replaced by an ALTERNATIVE depending on X86_FEATURE_XENPV. There are several instances using the PV-aware SWAPGS macro in paths which are never executed in a Xen PV guest. Replace those with the plain swapgs instruction. For SWAPGS_UNSAFE_STACK the same applies. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210120135555.32594-5-jgross@suse.com |
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Linus Torvalds
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f5a376edde |
A single fix for objtool to generate proper unwind info for newer
toolchains which do not generate section symbols anymore. And a cleanup ontop. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmAWi8EACgkQEsHwGGHe VUrZhBAAmbaEBdU05+ah24r+XHLsCJBQwlwHAr71YfNnEpq/KRHXLtc3QJLAdOVf ku0536gDJvMUX7d7ap2ooSVAD9Ed1h4N7BvOn8eLFiaPc6NG9Tw6FZc/X6OKtyLd DyFOsNAa9JnjjeqT7TTYdqbcJUzPSqd3Ufg5V4UZcVwvGTkbc+k1TktnteTMXWUI t99wXCOfw2accdUrr3MIkdvSGNo099VZa/DBZQVmpjCcMSOfe/0KQIoeVagEpAew T0WxONdM62Nz4Tv03N6m6EqVpIOc8BueRuOWlX/c5XVCmYx8BDSdFb6EY9sEh10i hLU1U36BCUT1uAA/ZAuw/I22fy5MXqbrGvWJrcW8Wav1fQfaDYkDyGNE+aBjXysQ uZGTzbfAdAS2B8XTElzYJZwh1WW7Je7b2pZhL5/6kwoa8E82NsR7a2inl6pdkKin LcrLlxrSZYbAjhYuA3Da4iErvtu/UloQwfDhga7NasGdVQzlwUQBX67Tgt1PA9B2 JWoeY1NKBGboNEQa3NWq37yCtfcpx2hL4wWgyUbj0TMOXO06V/ZhrPzIQDrMmVGx g52NrYnH/CujrKgWH3+Q+kBWA/BSVP5p3UnhLCDM1X7dyZiimuLOJNDUQ9WldENV rsGgKyW3/6F4UzmqLr0oOB6X9/2v15LSktN9BJtv3UWUCl/PfXU= =VV7d -----END PGP SIGNATURE----- Merge tag 'x86_entry_for_v5.11_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fix from Borislav Petkov: "A single fix for objtool to generate proper unwind info for newer toolchains which do not generate section symbols anymore. And a cleanup ontop. This was originally going to go during the next merge window but people can already trigger a build error with binutils-2.36 which doesn't emit section symbols - something which objtool relies on - so let's expedite it" * tag 'x86_entry_for_v5.11_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/entry: Remove put_ret_addr_in_rdi THUNK macro argument x86/entry: Emit a symbol for register restoring thunk |
||
Christian Brauner
|
2a1867219c
|
fs: add mount_setattr()
This implements the missing mount_setattr() syscall. While the new mount
api allows to change the properties of a superblock there is currently
no way to change the properties of a mount or a mount tree using file
descriptors which the new mount api is based on. In addition the old
mount api has the restriction that mount options cannot be applied
recursively. This hasn't changed since changing mount options on a
per-mount basis was implemented in [1] and has been a frequent request
not just for convenience but also for security reasons. The legacy
mount syscall is unable to accommodate this behavior without introducing
a whole new set of flags because MS_REC | MS_REMOUNT | MS_BIND |
MS_RDONLY | MS_NOEXEC | [...] only apply the mount option to the topmost
mount. Changing MS_REC to apply to the whole mount tree would mean
introducing a significant uapi change and would likely cause significant
regressions.
The new mount_setattr() syscall allows to recursively clear and set
mount options in one shot. Multiple calls to change mount options
requesting the same changes are idempotent:
int mount_setattr(int dfd, const char *path, unsigned flags,
struct mount_attr *uattr, size_t usize);
Flags to modify path resolution behavior are specified in the @flags
argument. Currently, AT_EMPTY_PATH, AT_RECURSIVE, AT_SYMLINK_NOFOLLOW,
and AT_NO_AUTOMOUNT are supported. If useful, additional lookup flags to
restrict path resolution as introduced with openat2() might be supported
in the future.
The mount_setattr() syscall can be expected to grow over time and is
designed with extensibility in mind. It follows the extensible syscall
pattern we have used with other syscalls such as openat2(), clone3(),
sched_{set,get}attr(), and others.
The set of mount options is passed in the uapi struct mount_attr which
currently has the following layout:
struct mount_attr {
__u64 attr_set;
__u64 attr_clr;
__u64 propagation;
__u64 userns_fd;
};
The @attr_set and @attr_clr members are used to clear and set mount
options. This way a user can e.g. request that a set of flags is to be
raised such as turning mounts readonly by raising MOUNT_ATTR_RDONLY in
@attr_set while at the same time requesting that another set of flags is
to be lowered such as removing noexec from a mount tree by specifying
MOUNT_ATTR_NOEXEC in @attr_clr.
Note, since the MOUNT_ATTR_<atime> values are an enum starting from 0,
not a bitmap, users wanting to transition to a different atime setting
cannot simply specify the atime setting in @attr_set, but must also
specify MOUNT_ATTR__ATIME in the @attr_clr field. So we ensure that
MOUNT_ATTR__ATIME can't be partially set in @attr_clr and that @attr_set
can't have any atime bits set if MOUNT_ATTR__ATIME isn't set in
@attr_clr.
The @propagation field lets callers specify the propagation type of a
mount tree. Propagation is a single property that has four different
settings and as such is not really a flag argument but an enum.
Specifically, it would be unclear what setting and clearing propagation
settings in combination would amount to. The legacy mount() syscall thus
forbids the combination of multiple propagation settings too. The goal
is to keep the semantics of mount propagation somewhat simple as they
are overly complex as it is.
The @userns_fd field lets user specify a user namespace whose idmapping
becomes the idmapping of the mount. This is implemented and explained in
detail in the next patch.
[1]: commit
|
||
Borislav Petkov
|
0bab9cb2d9 |
x86/entry: Remove put_ret_addr_in_rdi THUNK macro argument
That logic is unused since
|
||
Nick Desaulniers
|
5e6dca82bc |
x86/entry: Emit a symbol for register restoring thunk
Arnd found a randconfig that produces the warning: arch/x86/entry/thunk_64.o: warning: objtool: missing symbol for insn at offset 0x3e when building with LLVM_IAS=1 (Clang's integrated assembler). Josh notes: With the LLVM assembler not generating section symbols, objtool has no way to reference this code when it generates ORC unwinder entries, because this code is outside of any ELF function. The limitation now being imposed by objtool is that all code must be contained in an ELF symbol. And .L symbols don't create such symbols. So basically, you can use an .L symbol *inside* a function or a code segment, you just can't use the .L symbol to contain the code using a SYM_*_START/END annotation pair. Fangrui notes that this optimization is helpful for reducing image size when compiling with -ffunction-sections and -fdata-sections. I have observed on the order of tens of thousands of symbols for the kernel images built with those flags. A patch has been authored against GNU binutils to match this behavior of not generating unused section symbols ([1]), so this will also become a problem for users of GNU binutils once they upgrade to 2.36. Omit the .L prefix on a label so that the assembler will emit an entry into the symbol table for the label, with STB_LOCAL binding. This enables objtool to generate proper unwind info here with LLVM_IAS=1 or GNU binutils 2.36+. [ bp: Massage commit message. ] Reported-by: Arnd Bergmann <arnd@arndb.de> Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com> Suggested-by: Borislav Petkov <bp@alien8.de> Suggested-by: Mark Brown <broonie@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20210112194625.4181814-1-ndesaulniers@google.com Link: https://github.com/ClangBuiltLinux/linux/issues/1209 Link: https://reviews.llvm.org/D93783 Link: https://sourceware.org/binutils/docs/as/Symbol-Names.html Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d1bcae833b32f1408485ce69f844dcd7ded093a8 [1] |
||
Peter Zijlstra
|
9caa7ff509 |
x86/entry: Fix noinstr fail
vmlinux.o: warning: objtool: __do_fast_syscall_32()+0x47: call to syscall_enter_from_user_mode_work() leaves .noinstr.text section
Fixes:
|
||
Willem de Bruijn
|
b0a0c2615f |
epoll: wire up syscall epoll_pwait2
Split off from prev patch in the series that implements the syscall. Link: https://lkml.kernel.org/r/20201121144401.3727659-4-willemdebruijn.kernel@gmail.com Signed-off-by: Willem de Bruijn <willemb@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Linus Torvalds
|
ac73e3dc8a |
Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
- a few random little subsystems
- almost all of the MM patches which are staged ahead of linux-next
material. I'll trickle to post-linux-next work in as the dependents
get merged up.
Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
mm: cleanup kstrto*() usage
mm: fix fall-through warnings for Clang
mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
mm:backing-dev: use sysfs_emit in macro defining functions
mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
mm: use sysfs_emit for struct kobject * uses
mm: fix kernel-doc markups
zram: break the strict dependency from lzo
zram: add stat to gather incompressible pages since zram set up
zram: support page writeback
mm/process_vm_access: remove redundant initialization of iov_r
mm/zsmalloc.c: rework the list_add code in insert_zspage()
mm/zswap: move to use crypto_acomp API for hardware acceleration
mm/zswap: fix passing zero to 'PTR_ERR' warning
mm/zswap: make struct kernel_param_ops definitions const
userfaultfd/selftests: hint the test runner on required privilege
userfaultfd/selftests: fix retval check for userfaultfd_open()
userfaultfd/selftests: always dump something in modes
userfaultfd: selftests: make __{s,u}64 format specifiers portable
...
|
||
Dmitry Safonov
|
871402e05b |
mm: forbid splitting special mappings
Don't allow splitting of vm_special_mapping's. It affects vdso/vvar areas. Uprobes have only one page in xol_area so they aren't affected. Those restrictions were enforced by checks in .mremap() callbacks. Restrict resizing with generic .split() callback. Link: https://lkml.kernel.org/r/20201013013416.390574-7-dima@arista.com Signed-off-by: Dmitry Safonov <dima@arista.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Geffon <bgeffon@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Linus Torvalds
|
1ac0884d54 |
A set of updates for entry/exit handling:
- More generalization of entry/exit functionality
- The consolidation work to reclaim TIF flags on x86 and also for non-x86
specific TIF flags which are solely relevant for syscall related work
and have been moved into their own storage space. The x86 specific part
had to be merged in to avoid a major conflict.
- The TIF_NOTIFY_SIGNAL work which replaces the inefficient signal
delivery mode of task work and results in an impressive performance
improvement for io_uring. The non-x86 consolidation of this is going to
come seperate via Jens.
- The selective syscall redirection facility which provides a clean and
efficient way to support the non-Linux syscalls of WINE by catching them
at syscall entry and redirecting them to the user space emulation. This
can be utilized for other purposes as well and has been designed
carefully to avoid overhead for the regular fastpath. This includes the
core changes and the x86 support code.
- Simplification of the context tracking entry/exit handling for the users
of the generic entry code which guarantee the proper ordering and
protection.
- Preparatory changes to make the generic entry code accomodate S390
specific requirements which are mostly related to their syscall restart
mechanism.
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Merge tag 'core-entry-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core entry/exit updates from Thomas Gleixner:
"A set of updates for entry/exit handling:
- More generalization of entry/exit functionality
- The consolidation work to reclaim TIF flags on x86 and also for
non-x86 specific TIF flags which are solely relevant for syscall
related work and have been moved into their own storage space. The
x86 specific part had to be merged in to avoid a major conflict.
- The TIF_NOTIFY_SIGNAL work which replaces the inefficient signal
delivery mode of task work and results in an impressive performance
improvement for io_uring. The non-x86 consolidation of this is
going to come seperate via Jens.
- The selective syscall redirection facility which provides a clean
and efficient way to support the non-Linux syscalls of WINE by
catching them at syscall entry and redirecting them to the user
space emulation. This can be utilized for other purposes as well
and has been designed carefully to avoid overhead for the regular
fastpath. This includes the core changes and the x86 support code.
- Simplification of the context tracking entry/exit handling for the
users of the generic entry code which guarantee the proper ordering
and protection.
- Preparatory changes to make the generic entry code accomodate S390
specific requirements which are mostly related to their syscall
restart mechanism"
* tag 'core-entry-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
entry: Add syscall_exit_to_user_mode_work()
entry: Add exit_to_user_mode() wrapper
entry_Add_enter_from_user_mode_wrapper
entry: Rename exit_to_user_mode()
entry: Rename enter_from_user_mode()
docs: Document Syscall User Dispatch
selftests: Add benchmark for syscall user dispatch
selftests: Add kselftest for syscall user dispatch
entry: Support Syscall User Dispatch on common syscall entry
kernel: Implement selective syscall userspace redirection
signal: Expose SYS_USER_DISPATCH si_code type
x86: vdso: Expose sigreturn address on vdso to the kernel
MAINTAINERS: Add entry for common entry code
entry: Fix boot for !CONFIG_GENERIC_ENTRY
x86: Support HAVE_CONTEXT_TRACKING_OFFSTACK
context_tracking: Only define schedule_user() on !HAVE_CONTEXT_TRACKING_OFFSTACK archs
sched: Detect call to schedule from critical entry code
context_tracking: Don't implement exception_enter/exit() on CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK
context_tracking: Introduce HAVE_CONTEXT_TRACKING_OFFSTACK
x86: Reclaim unused x86 TI flags
...
|
||
|
Linus Torvalds
|
405f868f13 |
- Remove all uses of TIF_IA32 and TIF_X32 and reclaim the two bits in the end
(Gabriel Krisman Bertazi)
- All kinds of minor cleanups all over the tree.
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Merge tag 'x86_cleanups_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Borislav Petkov:
"Another branch with a nicely negative diffstat, just the way I
like 'em:
- Remove all uses of TIF_IA32 and TIF_X32 and reclaim the two bits in
the end (Gabriel Krisman Bertazi)
- All kinds of minor cleanups all over the tree"
* tag 'x86_cleanups_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
x86/ia32_signal: Propagate __user annotation properly
x86/alternative: Update text_poke_bp() kernel-doc comment
x86/PCI: Make a kernel-doc comment a normal one
x86/asm: Drop unused RDPID macro
x86/boot/compressed/64: Use TEST %reg,%reg instead of CMP $0,%reg
x86/head64: Remove duplicate include
x86/mm: Declare 'start' variable where it is used
x86/head/64: Remove unused GET_CR2_INTO() macro
x86/boot: Remove unused finalize_identity_maps()
x86/uaccess: Document copy_from_user_nmi()
x86/dumpstack: Make show_trace_log_lvl() static
x86/mtrr: Fix a kernel-doc markup
x86/setup: Remove unused MCA variables
x86, libnvdimm/test: Remove COPY_MC_TEST
x86: Reclaim TIF_IA32 and TIF_X32
x86/mm: Convert mmu context ia32_compat into a proper flags field
x86/elf: Use e_machine to check for x32/ia32 in setup_additional_pages()
elf: Expose ELF header on arch_setup_additional_pages()
x86/elf: Use e_machine to select start_thread for x32
elf: Expose ELF header in compat_start_thread()
...
|
||
Gabriel Krisman Bertazi
|
c5c878125a |
x86: vdso: Expose sigreturn address on vdso to the kernel
Syscall user redirection requires the signal trampoline code to not be captured, in order to support returning with a locked selector while avoiding recursion back into the signal handler. For ia-32, which has the trampoline in the vDSO, expose the entry points to the kernel, such that it can avoid dispatching syscalls from that region to userspace. Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Andy Lutomirski <luto@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20201127193238.821364-2-krisman@collabora.com |
||
Sean Christopherson
|
8466436952 |
x86/vdso: Implement a vDSO for Intel SGX enclave call
Enclaves encounter exceptions for lots of reasons: everything from enclave page faults to NULL pointer dereferences, to system calls that must be “proxied” to the kernel from outside the enclave. In addition to the code contained inside an enclave, there is also supporting code outside the enclave called an “SGX runtime”, which is virtually always implemented inside a shared library. The runtime helps build the enclave and handles things like *re*building the enclave if it got destroyed by something like a suspend/resume cycle. The rebuilding has traditionally been handled in SIGSEGV handlers, registered by the library. But, being process-wide, shared state, signal handling and shared libraries do not mix well. Introduce a vDSO function call that wraps the enclave entry functions (EENTER/ERESUME functions of the ENCLU instruciton) and returns information about any exceptions to the caller in the SGX runtime. Instead of generating a signal, the kernel places exception information in RDI, RSI and RDX. The kernel-provided userspace portion of the vDSO handler will place this information in a user-provided buffer or trigger a user-provided callback at the time of the exception. The vDSO function calling convention uses the standard RDI RSI, RDX, RCX, R8 and R9 registers. This makes it possible to declare the vDSO as a C prototype, but other than that there is no specific support for SystemV ABI. Things like storing XSAVE are the responsibility of the enclave and the runtime. [ bp: Change vsgx.o build dependency to CONFIG_X86_SGX. ] Suggested-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Cedric Xing <cedric.xing@intel.com> Signed-off-by: Cedric Xing <cedric.xing@intel.com> Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-20-jarkko@kernel.org |
||
|
Sean Christopherson
|
8382c668ce |
x86/vdso: Add support for exception fixup in vDSO functions
Signals are a horrid little mechanism. They are especially nasty in multi-threaded environments because signal state like handlers is global across the entire process. But, signals are basically the only way that userspace can “gracefully” handle and recover from exceptions. The kernel generally does not like exceptions to occur during execution. But, exceptions are a fact of life and must be handled in some circumstances. The kernel handles them by keeping a list of individual instructions which may cause exceptions. Instead of truly handling the exception and returning to the instruction that caused it, the kernel instead restarts execution at a *different* instruction. This makes it obvious to that thread of execution that the exception occurred and lets *that* code handle the exception instead of the handler. This is not dissimilar to the try/catch exceptions mechanisms that some programming languages have, but applied *very* surgically to single instructions. It effectively changes the visible architecture of the instruction. Problem ======= SGX generates a lot of signals, and the code to enter and exit enclaves and muck with signal handling is truly horrid. At the same time, an approach like kernel exception fixup can not be easily applied to userspace instructions because it changes the visible instruction architecture. Solution ======== The vDSO is a special page of kernel-provided instructions that run in userspace. Any userspace calling into the vDSO knows that it is special. This allows the kernel a place to legitimately rewrite the user/kernel contract and change instruction behavior. Add support for fixing up exceptions that occur while executing in the vDSO. This replaces what could traditionally only be done with signal handling. This new mechanism will be used to replace previously direct use of SGX instructions by userspace. Just introduce the vDSO infrastructure. Later patches will actually replace signal generation with vDSO exception fixup. Suggested-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-17-jarkko@kernel.org |
||
|
Thomas Gleixner
|
4cffe21d4a |
Merge branch 'x86/entry' into core/entry
Prepare for the merging of the syscall_work series which conflicts with the TIF bits overhaul in X86. |
||
|
Thomas Gleixner
|
b6be002bcd |
x86/entry: Move nmi entry/exit into common code
Lockdep state handling on NMI enter and exit is nothing specific to X86. It's not any different on other architectures. Also the extra state type is not necessary, irqentry_state_t can carry the necessary information as well. Move it to common code and extend irqentry_state_t to carry lockdep state. [ Ira: Make exit_rcu and lockdep a union as they are mutually exclusive between the IRQ and NMI exceptions, and add kernel documentation for struct irqentry_state_t ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201102205320.1458656-7-ira.weiny@intel.com |
||
|
Linus Torvalds
|
ed8780e3f2 |
A couple of x86 fixes which missed rc1 due to my stupidity:
- Drop lazy TLB mode before switching to the temporary address space for
text patching. text_poke() switches to the temporary mm which clears
the lazy mode and restores the original mm afterwards. Due to clearing
lazy mode this might restore a already dead mm if exit_mmap() runs in
parallel on another CPU.
- Document the x32 syscall design fail vs. syscall numbers 512-547
properly.
- Fix the ORC unwinder to handle the inactive task frame correctly. This
was unearthed due to the slightly different code generation of GCC10.
- Use an up to date screen_info for the boot params of kexec instead of
the possibly stale and invalid version which happened to be valid when
the kexec kernel was loaded.
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Merge tag 'x86-urgent-2020-10-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A couple of x86 fixes which missed rc1 due to my stupidity:
- Drop lazy TLB mode before switching to the temporary address space
for text patching.
text_poke() switches to the temporary mm which clears the lazy mode
and restores the original mm afterwards. Due to clearing lazy mode
this might restore a already dead mm if exit_mmap() runs in
parallel on another CPU.
- Document the x32 syscall design fail vs. syscall numbers 512-547
properly.
- Fix the ORC unwinder to handle the inactive task frame correctly.
This was unearthed due to the slightly different code generation of
gcc-10.
- Use an up to date screen_info for the boot params of kexec instead
of the possibly stale and invalid version which happened to be
valid when the kexec kernel was loaded"
* tag 'x86-urgent-2020-10-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/alternative: Don't call text_poke() in lazy TLB mode
x86/syscalls: Document the fact that syscalls 512-547 are a legacy mistake
x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels
hyperv_fb: Update screen_info after removing old framebuffer
x86/kexec: Use up-to-dated screen_info copy to fill boot params
|
||
|
Gabriel Krisman Bertazi
|
ff170cd059 |
x86/mm: Convert mmu context ia32_compat into a proper flags field
The ia32_compat attribute is a weird thing. It mirrors TIF_IA32 and TIF_X32 and is used only in two very unrelated places: (1) to decide if the vsyscall page is accessible (2) for uprobes to find whether the patched instruction is 32 or 64 bit. In preparation to remove the TIF flags, a new mechanism is required for ia32_compat, but given its odd semantics, adding a real flags field which configures these specific behaviours is the best option. So, set_personality_x64() can ask for the vsyscall page, which is not available in x32/ia32 and set_personality_ia32() can configure the uprobe code as needed. uprobe cannot rely on other methods like user_64bit_mode() to decide how to patch, so it needs some specific flag like this. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski<luto@kernel.org> Link: https://lore.kernel.org/r/20201004032536.1229030-10-krisman@collabora.com |
||
|
Gabriel Krisman Bertazi
|
3316ec8ccd |
x86/elf: Use e_machine to check for x32/ia32 in setup_additional_pages()
Since TIF_X32 is going away, avoid using it to find the ELF type when choosing which additional pages to set up. According to SysV AMD64 ABI Draft, an AMD64 ELF object using ILP32 must have ELFCLASS32 with (E_MACHINE == EM_X86_64), so use that ELF field to differentiate a x32 object from a IA32 object when executing setup_additional_pages() in compat mode. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201004032536.1229030-9-krisman@collabora.com |
||
|
Linus Torvalds
|
746b25b1aa |
Kbuild updates for v5.10
- Support 'make compile_commands.json' to generate the compilation
database more easily, avoiding stale entries
- Support 'make clang-analyzer' and 'make clang-tidy' for static checks
using clang-tidy
- Preprocess scripts/modules.lds.S to allow CONFIG options in the module
linker script
- Drop cc-option tests from compiler flags supported by our minimal
GCC/Clang versions
- Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y
- Use sha1 build id for both BFD linker and LLD
- Improve deb-pkg for reproducible builds and rootless builds
- Remove stale, useless scripts/namespace.pl
- Turn -Wreturn-type warning into error
- Fix build error of deb-pkg when CONFIG_MODULES=n
- Replace 'hostname' command with more portable 'uname -n'
- Various Makefile cleanups
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Merge tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Support 'make compile_commands.json' to generate the compilation
database more easily, avoiding stale entries
- Support 'make clang-analyzer' and 'make clang-tidy' for static checks
using clang-tidy
- Preprocess scripts/modules.lds.S to allow CONFIG options in the
module linker script
- Drop cc-option tests from compiler flags supported by our minimal
GCC/Clang versions
- Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y
- Use sha1 build id for both BFD linker and LLD
- Improve deb-pkg for reproducible builds and rootless builds
- Remove stale, useless scripts/namespace.pl
- Turn -Wreturn-type warning into error
- Fix build error of deb-pkg when CONFIG_MODULES=n
- Replace 'hostname' command with more portable 'uname -n'
- Various Makefile cleanups
* tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits)
kbuild: Use uname for LINUX_COMPILE_HOST detection
kbuild: Only add -fno-var-tracking-assignments for old GCC versions
kbuild: remove leftover comment for filechk utility
treewide: remove DISABLE_LTO
kbuild: deb-pkg: clean up package name variables
kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n
kbuild: enforce -Werror=return-type
scripts: remove namespace.pl
builddeb: Add support for all required debian/rules targets
builddeb: Enable rootless builds
builddeb: Pass -n to gzip for reproducible packages
kbuild: split the build log of kallsyms
kbuild: explicitly specify the build id style
scripts/setlocalversion: make git describe output more reliable
kbuild: remove cc-option test of -Werror=date-time
kbuild: remove cc-option test of -fno-stack-check
kbuild: remove cc-option test of -fno-strict-overflow
kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles
kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan
kbuild: do not create built-in objects for external module builds
...
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Sami Tolvanen
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0f6372e522 |
treewide: remove DISABLE_LTO
This change removes all instances of DISABLE_LTO from Makefiles, as they are currently unused, and the preferred method of disabling LTO is to filter out the flags instead. Note added by Masahiro Yamada: DISABLE_LTO was added as preparation for GCC LTO, but GCC LTO was not pulled into the mainline. (https://lkml.org/lkml/2014/4/8/272) Suggested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> |
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Minchan Kim
|
ecb8ac8b1f |
mm/madvise: introduce process_madvise() syscall: an external memory hinting API
There is usecase that System Management Software(SMS) want to give a
memory hint like MADV_[COLD|PAGEEOUT] to other processes and in the
case of Android, it is the ActivityManagerService.
The information required to make the reclaim decision is not known to the
app. Instead, it is known to the centralized userspace
daemon(ActivityManagerService), and that daemon must be able to initiate
reclaim on its own without any app involvement.
To solve the issue, this patch introduces a new syscall
process_madvise(2). It uses pidfd of an external process to give the
hint. It also supports vector address range because Android app has
thousands of vmas due to zygote so it's totally waste of CPU and power if
we should call the syscall one by one for each vma.(With testing 2000-vma
syscall vs 1-vector syscall, it showed 15% performance improvement. I
think it would be bigger in real practice because the testing ran very
cache friendly environment).
Another potential use case for the vector range is to amortize the cost
ofTLB shootdowns for multiple ranges when using MADV_DONTNEED; this could
benefit users like TCP receive zerocopy and malloc implementations. In
future, we could find more usecases for other advises so let's make it
happens as API since we introduce a new syscall at this moment. With
that, existing madvise(2) user could replace it with process_madvise(2)
with their own pid if they want to have batch address ranges support
feature.
ince it could affect other process's address range, only privileged
process(PTRACE_MODE_ATTACH_FSCREDS) or something else(e.g., being the same
UID) gives it the right to ptrace the process could use it successfully.
The flag argument is reserved for future use if we need to extend the API.
I think supporting all hints madvise has/will supported/support to
process_madvise is rather risky. Because we are not sure all hints make
sense from external process and implementation for the hint may rely on
the caller being in the current context so it could be error-prone. Thus,
I just limited hints as MADV_[COLD|PAGEOUT] in this patch.
If someone want to add other hints, we could hear the usecase and review
it for each hint. It's safer for maintenance rather than introducing a
buggy syscall but hard to fix it later.
So finally, the API is as follows,
ssize_t process_madvise(int pidfd, const struct iovec *iovec,
unsigned long vlen, int advice, unsigned int flags);
DESCRIPTION
The process_madvise() system call is used to give advice or directions
to the kernel about the address ranges from external process as well as
local process. It provides the advice to address ranges of process
described by iovec and vlen. The goal of such advice is to improve
system or application performance.
The pidfd selects the process referred to by the PID file descriptor
specified in pidfd. (See pidofd_open(2) for further information)
The pointer iovec points to an array of iovec structures, defined in
<sys/uio.h> as:
struct iovec {
void *iov_base; /* starting address */
size_t iov_len; /* number of bytes to be advised */
};
The iovec describes address ranges beginning at address(iov_base)
and with size length of bytes(iov_len).
The vlen represents the number of elements in iovec.
The advice is indicated in the advice argument, which is one of the
following at this moment if the target process specified by pidfd is
external.
MADV_COLD
MADV_PAGEOUT
Permission to provide a hint to external process is governed by a
ptrace access mode PTRACE_MODE_ATTACH_FSCREDS check; see ptrace(2).
The process_madvise supports every advice madvise(2) has if target
process is in same thread group with calling process so user could
use process_madvise(2) to extend existing madvise(2) to support
vector address ranges.
RETURN VALUE
On success, process_madvise() returns the number of bytes advised.
This return value may be less than the total number of requested
bytes, if an error occurred. The caller should check return value
to determine whether a partial advice occurred.
FAQ:
Q.1 - Why does any external entity have better knowledge?
Quote from Sandeep
"For Android, every application (including the special SystemServer)
are forked from Zygote. The reason of course is to share as many
libraries and classes between the two as possible to benefit from the
preloading during boot.
After applications start, (almost) all of the APIs end up calling into
this SystemServer process over IPC (binder) and back to the
application.
In a fully running system, the SystemServer monitors every single
process periodically to calculate their PSS / RSS and also decides
which process is "important" to the user for interactivity.
So, because of how these processes start _and_ the fact that the
SystemServer is looping to monitor each process, it does tend to *know*
which address range of the application is not used / useful.
Besides, we can never rely on applications to clean things up
themselves. We've had the "hey app1, the system is low on memory,
please trim your memory usage down" notifications for a long time[1].
They rely on applications honoring the broadcasts and very few do.
So, if we want to avoid the inevitable killing of the application and
restarting it, some way to be able to tell the OS about unimportant
memory in these applications will be useful.
- ssp
Q.2 - How to guarantee the race(i.e., object validation) between when
giving a hint from an external process and get the hint from the target
process?
process_madvise operates on the target process's address space as it
exists at the instant that process_madvise is called. If the space
target process can run between the time the process_madvise process
inspects the target process address space and the time that
process_madvise is actually called, process_madvise may operate on
memory regions that the calling process does not expect. It's the
responsibility of the process calling process_madvise to close this
race condition. For example, the calling process can suspend the
target process with ptrace, SIGSTOP, or the freezer cgroup so that it
doesn't have an opportunity to change its own address space before
process_madvise is called. Another option is to operate on memory
regions that the caller knows a priori will be unchanged in the target
process. Yet another option is to accept the race for certain
process_madvise calls after reasoning that mistargeting will do no
harm. The suggested API itself does not provide synchronization. It
also apply other APIs like move_pages, process_vm_write.
The race isn't really a problem though. Why is it so wrong to require
that callers do their own synchronization in some manner? Nobody
objects to write(2) merely because it's possible for two processes to
open the same file and clobber each other's writes --- instead, we tell
people to use flock or something. Think about mmap. It never
guarantees newly allocated address space is still valid when the user
tries to access it because other threads could unmap the memory right
before. That's where we need synchronization by using other API or
design from userside. It shouldn't be part of API itself. If someone
needs more fine-grained synchronization rather than process level,
there were two ideas suggested - cookie[2] and anon-fd[3]. Both are
applicable via using last reserved argument of the API but I don't
think it's necessary right now since we have already ways to prevent
the race so don't want to add additional complexity with more
fine-grained optimization model.
To make the API extend, it reserved an unsigned long as last argument
so we could support it in future if someone really needs it.
Q.3 - Why doesn't ptrace work?
Injecting an madvise in the target process using ptrace would not work
for us because such injected madvise would have to be executed by the
target process, which means that process would have to be runnable and
that creates the risk of the abovementioned race and hinting a wrong
VMA. Furthermore, we want to act the hint in caller's context, not the
callee's, because the callee is usually limited in cpuset/cgroups or
even freezed state so they can't act by themselves quick enough, which
causes more thrashing/kill. It doesn't work if the target process are
ptraced(e.g., strace, debugger, minidump) because a process can have at
most one ptracer.
[1] https://developer.android.com/topic/performance/memory"
[2] process_getinfo for getting the cookie which is updated whenever
vma of process address layout are changed - Daniel Colascione -
https://lore.kernel.org/lkml/20190520035254.57579-1-minchan@kernel.org/T/#m7694416fd179b2066a2c62b5b139b14e3894e224
[3] anonymous fd which is used for the object(i.e., address range)
validation - Michal Hocko -
https://lore.kernel.org/lkml/20200120112722.GY18451@dhcp22.suse.cz/
[minchan@kernel.org: fix process_madvise build break for arm64]
Link: http://lkml.kernel.org/r/20200303145756.GA219683@google.com
[minchan@kernel.org: fix build error for mips of process_madvise]
Link: http://lkml.kernel.org/r/20200508052517.GA197378@google.com
[akpm@linux-foundation.org: fix patch ordering issue]
[akpm@linux-foundation.org: fix arm64 whoops]
[minchan@kernel.org: make process_madvise() vlen arg have type size_t, per Florian]
[akpm@linux-foundation.org: fix i386 build]
[sfr@canb.auug.org.au: fix syscall numbering]
Link: https://lkml.kernel.org/r/20200905142639.49fc3f1a@canb.auug.org.au
[sfr@canb.auug.org.au: madvise.c needs compat.h]
Link: https://lkml.kernel.org/r/20200908204547.285646b4@canb.auug.org.au
[minchan@kernel.org: fix mips build]
Link: https://lkml.kernel.org/r/20200909173655.GC2435453@google.com
[yuehaibing@huawei.com: remove duplicate header which is included twice]
Link: https://lkml.kernel.org/r/20200915121550.30584-1-yuehaibing@huawei.com
[minchan@kernel.org: do not use helper functions for process_madvise]
Link: https://lkml.kernel.org/r/20200921175539.GB387368@google.com
[akpm@linux-foundation.org: pidfd_get_pid() gained an argument]
[sfr@canb.auug.org.au: fix up for "iov_iter: transparently handle compat iovecs in import_iovec"]
Link: https://lkml.kernel.org/r/20200928212542.468e1fef@canb.auug.org.au
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Christian Brauner <christian@brauner.io>
Cc: Daniel Colascione <dancol@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Dias <joaodias@google.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: SeongJae Park <sj38.park@gmail.com>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Tim Murray <timmurray@google.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Cc: <linux-man@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200302193630.68771-3-minchan@kernel.org
Link: http://lkml.kernel.org/r/20200508183320.GA125527@google.com
Link: http://lkml.kernel.org/r/20200622192900.22757-4-minchan@kernel.org
Link: https://lkml.kernel.org/r/20200901000633.1920247-4-minchan@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
Andy Lutomirski
|
c3b484c439 |
x86/syscalls: Document the fact that syscalls 512-547 are a legacy mistake
Since this commit:
|
||
|
Linus Torvalds
|
da9803dfd3 |
This feature enhances the current guest memory encryption support
called SEV by also encrypting the guest register state, making the
registers inaccessible to the hypervisor by en-/decrypting them on world
switches. Thus, it adds additional protection to Linux guests against
exfiltration, control flow and rollback attacks.
With SEV-ES, the guest is in full control of what registers the
hypervisor can access. This is provided by a guest-host exchange
mechanism based on a new exception vector called VMM Communication
Exception (#VC), a new instruction called VMGEXIT and a shared
Guest-Host Communication Block which is a decrypted page shared between
the guest and the hypervisor.
Intercepts to the hypervisor become #VC exceptions in an SEV-ES guest so
in order for that exception mechanism to work, the early x86 init code
needed to be made able to handle exceptions, which, in itself, brings
a bunch of very nice cleanups and improvements to the early boot code
like an early page fault handler, allowing for on-demand building of the
identity mapping. With that, !KASLR configurations do not use the EFI
page table anymore but switch to a kernel-controlled one.
The main part of this series adds the support for that new exchange
mechanism. The goal has been to keep this as much as possibly
separate from the core x86 code by concentrating the machinery in two
SEV-ES-specific files:
arch/x86/kernel/sev-es-shared.c
arch/x86/kernel/sev-es.c
Other interaction with core x86 code has been kept at minimum and behind
static keys to minimize the performance impact on !SEV-ES setups.
Work by Joerg Roedel and Thomas Lendacky and others.
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Merge tag 'x86_seves_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SEV-ES support from Borislav Petkov:
"SEV-ES enhances the current guest memory encryption support called SEV
by also encrypting the guest register state, making the registers
inaccessible to the hypervisor by en-/decrypting them on world
switches. Thus, it adds additional protection to Linux guests against
exfiltration, control flow and rollback attacks.
With SEV-ES, the guest is in full control of what registers the
hypervisor can access. This is provided by a guest-host exchange
mechanism based on a new exception vector called VMM Communication
Exception (#VC), a new instruction called VMGEXIT and a shared
Guest-Host Communication Block which is a decrypted page shared
between the guest and the hypervisor.
Intercepts to the hypervisor become #VC exceptions in an SEV-ES guest
so in order for that exception mechanism to work, the early x86 init
code needed to be made able to handle exceptions, which, in itself,
brings a bunch of very nice cleanups and improvements to the early
boot code like an early page fault handler, allowing for on-demand
building of the identity mapping. With that, !KASLR configurations do
not use the EFI page table anymore but switch to a kernel-controlled
one.
The main part of this series adds the support for that new exchange
mechanism. The goal has been to keep this as much as possibly separate
from the core x86 code by concentrating the machinery in two
SEV-ES-specific files:
arch/x86/kernel/sev-es-shared.c
arch/x86/kernel/sev-es.c
Other interaction with core x86 code has been kept at minimum and
behind static keys to minimize the performance impact on !SEV-ES
setups.
Work by Joerg Roedel and Thomas Lendacky and others"
* tag 'x86_seves_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (73 commits)
x86/sev-es: Use GHCB accessor for setting the MMIO scratch buffer
x86/sev-es: Check required CPU features for SEV-ES
x86/efi: Add GHCB mappings when SEV-ES is active
x86/sev-es: Handle NMI State
x86/sev-es: Support CPU offline/online
x86/head/64: Don't call verify_cpu() on starting APs
x86/smpboot: Load TSS and getcpu GDT entry before loading IDT
x86/realmode: Setup AP jump table
x86/realmode: Add SEV-ES specific trampoline entry point
x86/vmware: Add VMware-specific handling for VMMCALL under SEV-ES
x86/kvm: Add KVM-specific VMMCALL handling under SEV-ES
x86/paravirt: Allow hypervisor-specific VMMCALL handling under SEV-ES
x86/sev-es: Handle #DB Events
x86/sev-es: Handle #AC Events
x86/sev-es: Handle VMMCALL Events
x86/sev-es: Handle MWAIT/MWAITX Events
x86/sev-es: Handle MONITOR/MONITORX Events
x86/sev-es: Handle INVD Events
x86/sev-es: Handle RDPMC Events
x86/sev-es: Handle RDTSC(P) Events
...
|
||
|
Linus Torvalds
|
22230cd2c5 |
Merge branch 'compat.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull compat mount cleanups from Al Viro: "The last remnants of mount(2) compat buried by Christoph. Buried into NFS, that is. Generally I'm less enthusiastic about "let's use in_compat_syscall() deep in call chain" kind of approach than Christoph seems to be, but in this case it's warranted - that had been an NFS-specific wart, hopefully not to be repeated in any other filesystems (read: any new filesystem introducing non-text mount options will get NAKed even if it doesn't mess the layout up). IOW, not worth trying to grow an infrastructure that would avoid that use of in_compat_syscall()..." * 'compat.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: remove compat_sys_mount fs,nfs: lift compat nfs4 mount data handling into the nfs code nfs: simplify nfs4_parse_monolithic |
||
|
Linus Torvalds
|
e18afa5bfa |
Merge branch 'work.quota-compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull compat quotactl cleanups from Al Viro: "More Christoph's compat cleanups: quotactl(2)" * 'work.quota-compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: quota: simplify the quotactl compat handling compat: add a compat_need_64bit_alignment_fixup() helper compat: lift compat_s64 and compat_u64 to <asm-generic/compat.h> |
||
|
Linus Torvalds
|
85ed13e78d |
Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull compat iovec cleanups from Al Viro:
"Christoph's series around import_iovec() and compat variant thereof"
* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
security/keys: remove compat_keyctl_instantiate_key_iov
mm: remove compat_process_vm_{readv,writev}
fs: remove compat_sys_vmsplice
fs: remove the compat readv/writev syscalls
fs: remove various compat readv/writev helpers
iov_iter: transparently handle compat iovecs in import_iovec
iov_iter: refactor rw_copy_check_uvector and import_iovec
iov_iter: move rw_copy_check_uvector() into lib/iov_iter.c
compat.h: fix a spelling error in <linux/compat.h>
|
||
|
Linus Torvalds
|
ee4a925107 |
Clean up the paravirt code after the removal of 32-bit Xen PV support.
Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAl+EknMRHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1jfCw//SHuZDnhwJEA0W6smo3iWs3CIvvvEriM7 9ARjWparTD6P6ZXwW/xl76W+/QyzoWrsUDKHv9hFD5cpwafw5ZdCm4vhQi/tVLIc fqcEzG3I+UEqzs7K8NNVuEQs6b44diVPyVGEz7tRdufnKkXKU9Iyolc8zwa9OFB4 qknqQXHDfJ2Xsz4zRpwtiKHFq0ZyXzGiDY+O/AYKa8Zw25W0W6Hk3IoR2o2QgBr2 mE6VbhrO+woTEwMbNVi1fjioK2kQJ0PGleUQcaOz6rf8iMw/Ci4GJY70Yh3KIZMk VTNinCdC7GYwi0hsAsuas/dEIitn5B1zn3paN6wlNnpcjr1/Tn2oUw3euSju9X9a wvCMJX0ZoF/BLjoe7KSQAMCq0GaPNKWp9qP9gQFj/f1bUd4PC7yXRPJHZZlZfQPn M+jqsBye+GAbdeEzSjAutpU1gv4gjfF+heI8eLVtsYEmRmOfI6AxKm6MHjT0h6nK /krUyyTfi2IdXQ02FgbM8ufhXfAR6uXiaw4aCUoP53+gZR3R41aIxZ5rW4Tsfpxo jWeqYaVUpHnXY+Ses3Ziw1RGvpF0rrFP9xQv8jhsK1dJEPSIlpTahAgdYeQoIWFF 7WAsRscDtqiFHGr/RdX67LkcNik+GTxQx8moctk3PHueegTwZwyVBMsItlbJrj+q fitB13vg18Y= =n1W3 -----END PGP SIGNATURE----- Merge tag 'x86-paravirt-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 paravirt cleanup from Ingo Molnar: "Clean up the paravirt code after the removal of 32-bit Xen PV support" * tag 'x86-paravirt-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/paravirt: Avoid needless paravirt step clearing page table entries x86/paravirt: Remove set_pte_at() pv-op x86/entry/32: Simplify CONFIG_XEN_PV build dependency x86/paravirt: Use CONFIG_PARAVIRT_XXL instead of CONFIG_PARAVIRT x86/paravirt: Clean up paravirt macros x86/paravirt: Remove 32-bit support from CONFIG_PARAVIRT_XXL |
||
|
Linus Torvalds
|
f94ab23113 |
* Misc minor cleanups.
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||
|
Linus Torvalds
|
87194efe7e |
* Misc minor cleanups and corrections to the fsgsbase code and
respective selftests. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAl+EMr8ACgkQEsHwGGHe VUpoBQ/+Pe7MaMbS7d+IATzhedKW7PNKcQr2g734rnZkz0BgG+1sBkCQPRAKBZoa SIvt3gURM3aEeD4Dp3am4nLElyhldZrlwKoGKGv6AYv2BpLPQM9PG0fHJGUyYBze ekKMdPu5YK0hYqoWctrY8h+qbExNdkfAvM7bJMFJMBqypVicm0n5wlgfZthGz0DU tkD34WZNE2GGAfsi/NNJ2H+hcZo8bQVrqW98bkgdzIA7+KI3cyZZ132VbKxb03tK A69C7+J4B20q/traWFlb4mTcFy/a1Txrt3cJXIv/Xer74gDMqNYcciGgnTJdhryY gzBmWNTxuQr1EC8DYJaxjlQbBp6VSAwhELlyc6UeRxLAViEpMxyPfBVMOYqraImc sZ8QKGgI02PggInN9yo4qCbtUWAGMCHV7HGGW8stVBrh1lia7o6Dy9jhO+nmTnzV EEe/vEoSsp/ydnkgFNjaRwjFLp+vDX2lAf513ZuZukpt+IGQ0nAO5phzgcZVAyH4 qzr9uXdM3j+NtlXZgLttNppWEvHxzIpkri3Ly46VUFYOqTuKYPmS8A7stEfqx3NO T8g38+dDirFfKCoJz8NJBUUs+1KXer8QmJvogfHx5fsZ01Q2qz6AmOmsmMfe7Wqm +C9mvZJOJnW/7NunGWGVsuAZJOPx6o2oivjVpxxOyl8AeQnE6fg= =itDm -----END PGP SIGNATURE----- Merge tag 'x86_fsgsbase_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fsgsbase updates from Borislav Petkov: "Misc minor cleanups and corrections to the fsgsbase code and respective selftests" * tag 'x86_fsgsbase_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftests/x86/fsgsbase: Test PTRACE_PEEKUSER for GSBASE with invalid LDT GS selftests/x86/fsgsbase: Reap a forgotten child x86/fsgsbase: Replace static_cpu_has() with boot_cpu_has() x86/entry/64: Correct the comment over SAVE_AND_SET_GSBASE |
||
Bill Wendling
|
a968433723 |
kbuild: explicitly specify the build id style
ld's --build-id defaults to "sha1" style, while lld defaults to "fast". The build IDs are very different between the two, which may confuse programs that reference them. Signed-off-by: Bill Wendling <morbo@google.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> |
||
Christoph Hellwig
|
c3973b401e |
mm: remove compat_process_vm_{readv,writev}
Now that import_iovec handles compat iovecs, the native syscalls can be used for the compat case as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
||
|
Christoph Hellwig
|
598b3cec83 |
fs: remove compat_sys_vmsplice
Now that import_iovec handles compat iovecs, the native vmsplice syscall can be used for the compat case as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
||
|
Christoph Hellwig
|
5f764d624a |
fs: remove the compat readv/writev syscalls
Now that import_iovec handles compat iovecs, the native readv and writev syscalls can be used for the compat case as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
||
|
Christoph Hellwig
|
028abd9222 |
fs: remove compat_sys_mount
compat_sys_mount is identical to the regular sys_mount now, so remove it and use the native version everywhere. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
||
|
Thomas Gleixner
|
a7b3474cbb |
x86/irq: Make run_on_irqstack_cond() typesafe
Sami reported that run_on_irqstack_cond() requires the caller to cast
functions to mismatching types, which trips indirect call Control-Flow
Integrity (CFI) in Clang.
Instead of disabling CFI on that function, provide proper helpers for
the three call variants. The actual ASM code stays the same as that is
out of reach.
[ bp: Fix __run_on_irqstack() prototype to match. ]
Fixes:
|