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* | s390/kexec_file: Add crash support to image loaderPhilipp Rudo2018-04-162-5/+46
| | | | | | | | | | | | | | | | | | Add support to load a crash kernel to the image loader. This requires extending the purgatory. Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com> Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | s390/kexec_file: Add image loaderPhilipp Rudo2018-04-163-1/+154
| | | | | | | | | | | | | | | | | | | | Add an image loader for kexec_file_load. For simplicity first skip crash support. The functions defined in machine_kexec_file will later be shared with the ELF loader. Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com> Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | s390/kexec_file: Add kexec_file_load system callPhilipp Rudo2018-04-164-0/+130
| | | | | | | | | | | | | | | | | | This patch adds the kexec_file_load system call to s390 as well as the arch specific functions common code requires to work. Loaders for the different file types will be added later. Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | s390/kexec_file: Add purgatoryPhilipp Rudo2018-04-161-0/+5
|/ | | | | | | | | The common code expects the architecture to have a purgatory that runs between the two kernels. Add it now. For simplicity first skip crash support. Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: correct nospec auto detection init orderMartin Schwidefsky2018-04-112-6/+5
| | | | | | | | | | | | | | | | With CONFIG_EXPOLINE_AUTO=y the call of spectre_v2_auto_early() via early_initcall is done *after* the early_param functions. This overwrites any settings done with the nobp/no_spectre_v2/spectre_v2 parameters. The code patching for the kernel is done after the evaluation of the early parameters but before the early_initcall is done. The end result is a kernel image that is patched correctly but the kernel modules are not. Make sure that the nospec auto detection function is called before the early parameters are evaluated and before the code patching is done. Fixes: 6e179d64126b ("s390: add automatic detection of the spectre defense") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/ipl: remove reipl_method and dump_methodVasily Gorbik2018-04-101-46/+11
| | | | | | | | | | | | | reipl_method and dump_method have been used in addition to reipl_type and dump_type, because a single reipl_type could be achieved with multiple reipl_method (same for dump_type/method). After dropping non-diag308_set based reipl methods, there is a single method per reipl_type/dump_type and reipl_method and dump_method could be simply removed. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/ipl: correct kdump reipl block checksum calculationVasily Gorbik2018-04-102-6/+6
| | | | | | | | | | | | | | | | | | | | | | s390 kdump reipl implementation relies on os_info kernel structure residing in old memory being dumped. os_info contains reipl block, which is used (if valid) by the kdump kernel for reipl parameters. The problem is that the reipl block and its checksum inside os_info is updated only when /sys/firmware/reipl/reipl_type is written. This sets an offset of a reipl block for "reipl_type" and re-calculates reipl block checksum. Any further alteration of values under /sys/firmware/reipl/{reipl_type}/ without subsequent write to /sys/firmware/reipl/reipl_type lead to incorrect os_info reipl block checksum. In such a case kdump kernel ignores it and reboots using default logic. To fix this, os_info reipl block update is moved right before kdump execution. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: assume diag308 set always worksVasily Gorbik2018-04-104-336/+15
| | | | | | | | | | | | | | diag308 set has been available for many machine generations, and alternative reipl code paths has not been exercised and seems to be broken without noticing for a while now. So, cleaning up all obsolete reipl methods except currently used ones, assuming that diag308 set always works. Also removing not longer needed reset callbacks. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/ipl: avoid adding scpdata to cmdline during ftp/dvd bootVasily Gorbik2018-04-101-1/+1
| | | | | | | | Add missing ipl parmblock validity check to append_ipl_scpdata. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/ipl: correct ipl parmblock valid checksVasily Gorbik2018-04-101-6/+4
| | | | | | | | | | | In some cases diag308_set_works used to be misused as "we have valid ipl parmblock", which is not the case when diag308 set works, but there is no ipl parmblock (diag308 store returns DIAG308_RC_NOCONFIG). Such checks are adjusted to reuse ipl_block_valid instead of diag308_set_works. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/ipl: rely on diag308 store to get ipl infoVasily Gorbik2018-04-102-51/+16
| | | | | | | | | | For both ccw and fcp boot retrieve ipl info from ipl block received via diag308 store. Old scsi ipl parm block handling and cio_get_iplinfo are removed. Ipl type is deducted from ipl block (if valid). Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/ipl: move ipl_flags to ipl.cVasily Gorbik2018-04-101-1/+9
| | | | | | | | | ipl_flags and corresponding enum are not used outside of ipl.c and will be reworked in later commits. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/ipl: get rid of ipl_ssid and ipl_devnoVasily Gorbik2018-04-101-9/+8
| | | | | | | | | ipl_ssid and ipl_devno used to be used during ccw boot when diag308 store was not available. Reuse ipl_block to store those values. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/ipl: unite diag308 and scsi boot ipl blocksVasily Gorbik2018-04-101-25/+25
| | | | | | | | | Ipl parm blocks received via "diag308 store" and during scsi boot at IPL_PARMBLOCK_ORIGIN are merged into the "ipl_block". Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/ipl: ensure loadparm valid flag is setVasily Gorbik2018-04-101-0/+1
| | | | | | | | | | | | | When loadparm is set in reipl parm block, the kernel should also set DIAG308_FLAGS_LP_VALID flag. This fixes loadparm ignoring during z/VM fcp -> ccw reipl and kvm direct boot -> ccw reipl. Cc: <stable@vger.kernel.org> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/compat: fix setup_frame32Heiko Carstens2018-04-101-1/+1
| | | | | | | | | | | | | Git commit c60a03fee0e5 ("s390: switch to {get,put}_compat_sigset()") contains a typo and now copies the wrong pointer to user space. Use the correct pointer instead. Reported-and-tested-by: Stefan Liebler <stli@linux.vnet.ibm.com> Fixes: c60a03fee0e5 ("s390: switch to {get,put}_compat_sigset()") Cc: <stable@vger.kernel.org> # v4.15+ Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2018-04-099-140/+146
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: - Improvements for the spectre defense: * The spectre related code is consolidated to a single file nospec-branch.c * Automatic enable/disable for the spectre v2 defenses (expoline vs. nobp) * Syslog messages for specve v2 are added * Enable CONFIG_GENERIC_CPU_VULNERABILITIES and define the attribute functions for spectre v1 and v2 - Add helper macros for assembler alternatives and use them to shorten the code in entry.S. - Add support for persistent configuration data via the SCLP Store Data interface. The H/W interface requires a page table that uses 4K pages only, the code to setup such an address space is added as well. - Enable virtio GPU emulation in QEMU. To do this the depends statements for a few common Kconfig options are modified. - Add support for format-3 channel path descriptors and add a binary sysfs interface to export the associated utility strings. - Add a sysfs attribute to control the IFCC handling in case of constant channel errors. - The vfio-ccw changes from Cornelia. - Bug fixes and cleanups. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (40 commits) s390/kvm: improve stack frame constants in entry.S s390/lpp: use assembler alternatives for the LPP instruction s390/entry.S: use assembler alternatives s390: add assembler macros for CPU alternatives s390: add sysfs attributes for spectre s390: report spectre mitigation via syslog s390: add automatic detection of the spectre defense s390: move nobp parameter functions to nospec-branch.c s390/cio: add util_string sysfs attribute s390/chsc: query utility strings via fmt3 channel path descriptor s390/cio: rename struct channel_path_desc s390/cio: fix unbind of io_subchannel_driver s390/qdio: split up CCQ handling for EQBS / SQBS s390/qdio: don't retry EQBS after CCQ 96 s390/qdio: restrict buffer merging to eligible devices s390/qdio: don't merge ERROR output buffers s390/qdio: simplify math in get_*_buffer_frontier() s390/decompressor: trim uncompressed image head during the build s390/crypto: Fix kernel crash on aes_s390 module remove. s390/defkeymap: fix global init to zero ...
| * s390/kvm: improve stack frame constants in entry.SMartin Schwidefsky2018-03-282-13/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | The code in sie64a uses the stack frame passed to the function to store some temporary data in the empty1 array (see struct stack_frame in asm/processor.h. Replace the __SF_EMPTY+x constants with a properly defined offset: s/__SF_EMPTY/__SF_SIE_CONTROL/, s/__SF_EMPTY+8/__SF_SIE_SAVEAREA/, s/__SF_EMPTY+16/__SF_SIE_REASON/, s/__SF_EMPTY+24/__SF_SIE_FLAGS/. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390/lpp: use assembler alternatives for the LPP instructionMartin Schwidefsky2018-03-282-10/+6
| | | | | | | | | | | | | | | | With the new macros for CPU alternatives the MACHINE_FLAG_LPP check around the LPP instruction can be optimized. After this is done the flag can be removed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390/entry.S: use assembler alternativesMartin Schwidefsky2018-03-281-49/+7
| | | | | | | | | | | | | | | | Replace the open coded alternatives for the BPOFF, BPON, BPENTER, and BPEXIT macros with the new magic from asm/alternatives-asm.h to make the code easier to read. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390: add sysfs attributes for spectreMartin Schwidefsky2018-03-281-0/+19
| | | | | | | | | | | | | | | | Set CONFIG_GENERIC_CPU_VULNERABILITIES and provide the two functions cpu_show_spectre_v1 and cpu_show_spectre_v2 to report the spectre mitigations. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390: report spectre mitigation via syslogMartin Schwidefsky2018-03-281-0/+10
| | | | | | | | | | | | | | | | | | Add a boot message if either of the spectre defenses is active. The message is "Spectre V2 mitigation: execute trampolines." or "Spectre V2 mitigation: limited branch prediction." Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390: add automatic detection of the spectre defenseMartin Schwidefsky2018-03-283-32/+48
| | | | | | | | | | | | | | | | | | | | Automatically decide between nobp vs. expolines if the spectre_v2=auto kernel parameter is specified or CONFIG_EXPOLINE_AUTO=y is set. The decision made at boot time due to CONFIG_EXPOLINE_AUTO=y being set can be overruled with the nobp, nospec and spectre_v2 kernel parameters. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390: move nobp parameter functions to nospec-branch.cMartin Schwidefsky2018-03-283-25/+29
| | | | | | | | | | | | | | Keep the code for the nobp parameter handling with the code for expolines. Both are related to the spectre v2 mitigation. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390/setup : enable display support for KVM guestFarhan Ali2018-03-181-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The S390 architecture does not support any graphics hardware, but with the latest support for Virtio GPU in Linux and Virtio GPU emulation in QEMU, it's possible to enable graphics for S390 using the Virtio GPU device. To enable display we need to enable the Linux Virtual Terminal (VT) layer for S390. But the VT subsystem initializes quite early at boot so we need a dummy console driver till the Virtio GPU driver is initialized and we can run the framebuffer console. The framebuffer console over a Virtio GPU device can be run in combination with the serial SCLP console (default on S390). The SCLP console can still be accessed by management applications (eg: via Libvirt's virsh console). Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Message-Id: <e23b61f4f599ba23881727a1e8880e9d60cc6a48.1519315352.git.alifm@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390: unify linker symbols usageVasily Gorbik2018-02-273-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | Common code defines linker symbols which denote sections start/end in a form of char []. Referencing those symbols as _symbol or &_symbol yields the same result, but "_symbol" form is more widespread across newly written code. Convert s390 specific code to this style. Also removes unused _text symbol definition in boot/compressed/misc.c. Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | headers: untangle kmemleak.h from mm.hRandy Dunlap2018-04-052-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently <linux/slab.h> #includes <linux/kmemleak.h> for no obvious reason. It looks like it's only a convenience, so remove kmemleak.h from slab.h and add <linux/kmemleak.h> to any users of kmemleak_* that don't already #include it. Also remove <linux/kmemleak.h> from source files that do not use it. This is tested on i386 allmodconfig and x86_64 allmodconfig. It would be good to run it through the 0day bot for other $ARCHes. I have neither the horsepower nor the storage space for the other $ARCHes. Update: This patch has been extensively build-tested by both the 0day bot & kisskb/ozlabs build farms. Both of them reported 2 build failures for which patches are included here (in v2). [ slab.h is the second most used header file after module.h; kernel.h is right there with slab.h. There could be some minor error in the counting due to some #includes having comments after them and I didn't combine all of those. ] [akpm@linux-foundation.org: security/keys/big_key.c needs vmalloc.h, per sfr] Link: http://lkml.kernel.org/r/e4309f98-3749-93e1-4bb7-d9501a39d015@infradead.org Link: http://kisskb.ellerman.id.au/kisskb/head/13396/ Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Ingo Molnar <mingo@kernel.org> Reported-by: Michael Ellerman <mpe@ellerman.id.au> [2 build failures] Reported-by: Fengguang Wu <fengguang.wu@intel.com> [2 build failures] Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Wei Yongjun <weiyongjun1@huawei.com> Cc: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: John Johansen <john.johansen@canonical.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: add ksys_readahead() helper; remove in-kernel calls to sys_readahead()Dominik Brodowski2018-04-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using this helper allows us to avoid the in-kernel calls to the sys_readahead() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_readahead(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
* | mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff()Dominik Brodowski2018-04-022-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using this helper allows us to avoid the in-kernel calls to the sys_mmap_pgoff() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_mmap_pgoff(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
* | mm: add ksys_fadvise64_64() helper; remove in-kernel call to sys_fadvise64_64()Dominik Brodowski2018-04-021-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using the ksys_fadvise64_64() helper allows us to avoid the in-kernel calls to the sys_fadvise64_64() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as ksys_fadvise64_64(). Some compat stubs called sys_fadvise64(), which then just passed through the arguments to sys_fadvise64_64(). Get rid of this indirection, and call ksys_fadvise64_64() directly. This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
* | fs: add ksys_fallocate() wrapper; remove in-kernel calls to sys_fallocate()Dominik Brodowski2018-04-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using the ksys_fallocate() wrapper allows us to get rid of in-kernel calls to the sys_fallocate() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_fallocate(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
* | fs: add ksys_p{read,write}64() helpers; remove in-kernel calls to syscallsDominik Brodowski2018-04-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using the ksys_p{read,write}64() wrappers allows us to get rid of in-kernel calls to the sys_pread64() and sys_pwrite64() syscalls. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_p{read,write}64(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
* | fs: add ksys_truncate() wrapper; remove in-kernel calls to sys_truncate()Dominik Brodowski2018-04-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using the ksys_truncate() wrapper allows us to get rid of in-kernel calls to the sys_truncate() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_truncate(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
* | fs: add ksys_sync_file_range helper(); remove in-kernel calls to syscallDominik Brodowski2018-04-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using this helper allows us to avoid the in-kernel calls to the sys_sync_file_range() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_sync_file_range(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
* | fs: add ksys_read() helper; remove in-kernel calls to sys_read()Dominik Brodowski2018-04-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Using this helper allows us to avoid the in-kernel calls to the sys_read() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_read(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
* | fs: add ksys_ftruncate() wrapper; remove in-kernel calls to sys_ftruncate()Dominik Brodowski2018-04-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using the ksys_ftruncate() wrapper allows us to get rid of in-kernel calls to the sys_ftruncate() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_ftruncate(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
* | fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappersDominik Brodowski2018-04-021-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using the fs-interal do_fchownat() wrapper allows us to get rid of fs-internal calls to the sys_fchownat() syscall. Introducing the ksys_fchown() helper and the ksys_{,}chown() wrappers allows us to avoid the in-kernel calls to the sys_{,l,f}chown() syscalls. The ksys_ prefix denotes that these functions are meant as a drop-in replacement for the syscalls. In particular, they use the same calling convention as sys_{,l,f}chown(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
* | fs: add ksys_write() helper; remove in-kernel calls to sys_write()Dominik Brodowski2018-04-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using this helper allows us to avoid the in-kernel calls to the sys_write() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_write(). In the near future, the do_mounts / initramfs callers of ksys_write() should be converted to use filp_open() and vfs_write() instead. This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-s390@vger.kernel.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
* | s390/entry.S: fix spurious zeroing of r0Christian Borntraeger2018-03-061-2/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | when a system call is interrupted we might call the critical section cleanup handler that re-does some of the operations. When we are between .Lsysc_vtime and .Lsysc_do_svc we might also redo the saving of the problem state registers r0-r7: .Lcleanup_system_call: [...] 0: # update accounting time stamp mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER # set up saved register r11 lg %r15,__LC_KERNEL_STACK la %r9,STACK_FRAME_OVERHEAD(%r15) stg %r9,24(%r11) # r11 pt_regs pointer # fill pt_regs mvc __PT_R8(64,%r9),__LC_SAVE_AREA_SYNC ---> stmg %r0,%r7,__PT_R0(%r9) The problem is now, that we might have already zeroed out r0. The fix is to move the zeroing of r0 after sysc_do_svc. Reported-by: Farhan Ali <alifm@linux.vnet.ibm.com> Fixes: 7041d28115e91 ("s390: scrub registers on kernel entry and KVM exit") Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: do not bypass BPENTER for interrupt system callsMartin Schwidefsky2018-02-221-0/+1
| | | | | | | | | | | The system call path can be interrupted before the switch back to the standard branch prediction with BPENTER has been done. The critical section cleanup code skips forward to .Lsysc_do_svc and bypasses the BPENTER. In this case the kernel and all subsequent code will run with the limited branch prediction. Fixes: eacf67eb9b32 ("s390: run user space and KVM guests with modified branch prediction") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/clean-up: use CFI_* macros in entry.SHendrik Brueckner2018-02-221-2/+3
| | | | | | | | | | | | Commit f19fbd5ed642 ("s390: introduce execute-trampolines for branches") introduces .cfi_* assembler directives. Instead of using the directives directly, use the macros from asm/dwarf.h. This also ensures that the dwarf debug information are created in the .debug_frame section. Fixes: f19fbd5ed642 ("s390: introduce execute-trampolines for branches") Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: Replace IS_ENABLED(EXPOLINE_*) with IS_ENABLED(CONFIG_EXPOLINE_*)Eugeniu Rosca2018-02-191-2/+2
| | | | | | | | | I've accidentally stumbled upon the IS_ENABLED(EXPOLINE_*) lines, which obviously always evaluate to false. Fix this. Fixes: f19fbd5ed642 ("s390: introduce execute-trampolines for branches") Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: introduce execute-trampolines for branchesMartin Schwidefsky2018-02-077-34/+264
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add CONFIG_EXPOLINE to enable the use of the new -mindirect-branch= and -mfunction_return= compiler options to create a kernel fortified against the specte v2 attack. With CONFIG_EXPOLINE=y all indirect branches will be issued with an execute type instruction. For z10 or newer the EXRL instruction will be used, for older machines the EX instruction. The typical indirect call basr %r14,%r1 is replaced with a PC relative call to a new thunk brasl %r14,__s390x_indirect_jump_r1 The thunk contains the EXRL/EX instruction to the indirect branch __s390x_indirect_jump_r1: exrl 0,0f j . 0: br %r1 The detour via the execute type instruction has a performance impact. To get rid of the detour the new kernel parameter "nospectre_v2" and "spectre_v2=[on,off,auto]" can be used. If the parameter is specified the kernel and module code will be patched at runtime. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: run user space and KVM guests with modified branch predictionMartin Schwidefsky2018-02-052-5/+64
| | | | | | | | | | | | | Define TIF_ISOLATE_BP and TIF_ISOLATE_BP_GUEST and add the necessary plumbing in entry.S to be able to run user space and KVM guests with limited branch prediction. To switch a user space process to limited branch prediction the s390_isolate_bp() function has to be call, and to run a vCPU of a KVM guest associated with the current task with limited branch prediction call s390_isolate_bp_guest(). Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: add options to change branch prediction behaviour for the kernelMartin Schwidefsky2018-02-055-0/+76
| | | | | | | | | | | | Add the PPA instruction to the system entry and exit path to switch the kernel to a different branch prediction behaviour. The instructions are added via CPU alternatives and can be disabled with the "nospec" or the "nobp=0" kernel parameter. If the default behaviour selected with CONFIG_KERNEL_NOBP is set to "n" then the "nobp=1" parameter can be used to enable the changed kernel branch prediction. Acked-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/alternative: use a copy of the facility bit maskMartin Schwidefsky2018-02-054-3/+11
| | | | | | | | | | To be able to switch off specific CPU alternatives with kernel parameters make a copy of the facility bit mask provided by STFLE and use the copy for the decision to apply an alternative. Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: scrub registers on kernel entry and KVM exitMartin Schwidefsky2018-02-051-0/+47
| | | | | | | | | Clear all user space registers on entry to the kernel and all KVM guest registers on KVM guest exit if the register does not contain either a parameter or a result value. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/runtime_instrumentation: re-add signum system call parameterHeiko Carstens2018-02-051-1/+9
| | | | | | | | Add the signum system call parameter for documentation purposes only, and without checking if the passed value is a valid real-time signal. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/cpum_cf: correct counter number of LAST_HOST_TRANSLATIONSHendrik Brueckner2018-02-021-1/+1
| | | | | Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/kprobes: Fix %p uses in error messagesMasami Hiramatsu2018-02-021-1/+1
| | | | | | | | Remove %p because the kprobe will be dumped in dump_kprobe(). Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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