- 13 Jan, 2019 40 commits
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Sagi Grimberg authored
commit e48d8ed9 upstream. Error completions must still contain a valid wr_id and qp_num such that the consumer can rely on. Correctly fill these fields in receive error completions. Reported-by:
Walker Benjamin <benjamin.walker@intel.com> Cc: stable@vger.kernel.org Signed-off-by:
Sagi Grimberg <sagi@grimberg.me> Reviewed-by:
Zhu Yanjun <yanjun.zhu@oracle.com> Tested-by:
Doug Ledford <dledford@redhat.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Dominique Martinet authored
commit 574d356b upstream. If the requested msize is too small (either from command line argument or from the server version reply), we won't get any work done. If it's *really* too small, nothing will work, and this got caught by syzbot recently (on a new kmem_cache_create_usercopy() call) Just set a minimum msize to 4k in both code paths, until someone complains they have a use-case for a smaller msize. We need to check in both mount option and server reply individually because the msize for the first version request would be unchecked with just a global check on clnt->msize. Link: http://lkml.kernel.org/r/1541407968-31350-1-git-send-email-asmadeus@codewreck.org Reported-by: syzbot+0c1d61e4db7db94102ca@syzkaller.appspotmail.com Signed-off-by:
Dominique Martinet <dominique.martinet@cea.fr> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: stable@vger.kernel.org Signed-off-by:
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Breno Leitao authored
commit e1c3743e upstream. On a signal handler return, the user could set a context with MSR[TS] bits set, and these bits would be copied to task regs->msr. At restore_tm_sigcontexts(), after current task regs->msr[TS] bits are set, several __get_user() are called and then a recheckpoint is executed. This is a problem since a page fault (in kernel space) could happen when calling __get_user(). If it happens, the process MSR[TS] bits were already set, but recheckpoint was not executed, and SPRs are still invalid. The page fault can cause the current process to be de-scheduled, with MSR[TS] active and without tm_recheckpoint() being called. More importantly, without TEXASR[FS] bit set also. Since TEXASR might not have the FS bit set, and when the process is scheduled back, it will try to reclaim, which will be aborted because of the CPU is not in the suspended state, and, then, recheckpoint. This recheckpoint will restore thread->texasr into TEXASR SPR, which might be zero, hitting a BUG_ON(). kernel BUG at /build/linux-sf3Co9/linux-4.9.30/arch/powerpc/kernel/tm.S:434! cpu 0xb: Vector: 700 (Program Check) at [c00000041f1576d0] pc: c000000000054550: restore_gprs+0xb0/0x180 lr: 0000000000000000 sp: c00000041f157950 msr: 8000000100021033 current = 0xc00000041f143000 paca = 0xc00000000fb86300 softe: 0 irq_happened: 0x01 pid = 1021, comm = kworker/11:1 kernel BUG at /build/linux-sf3Co9/linux-4.9.30/arch/powerpc/kernel/tm.S:434! Linux version 4.9.0-3-powerpc64le (debian-kernel@lists.debian.org) (gcc version 6.3.0 20170516 (Debian 6.3.0-18) ) #1 SMP Debian 4.9.30-2+deb9u2 (2017-06-26) enter ? for help [c00000041f157b30] c00000000001bc3c tm_recheckpoint.part.11+0x6c/0xa0 [c00000041f157b70] c00000000001d184 __switch_to+0x1e4/0x4c0 [c00000041f157bd0] c00000000082eeb8 __schedule+0x2f8/0x990 [c00000041f157cb0] c00000000082f598 schedule+0x48/0xc0 [c00000041f157ce0] c0000000000f0d28 worker_thread+0x148/0x610 [c00000041f157d80] c0000000000f96b0 kthread+0x120/0x140 [c00000041f157e30] c00000000000c0e0 ret_from_kernel_thread+0x5c/0x7c This patch simply delays the MSR[TS] set, so, if there is any page fault in the __get_user() section, it does not have regs->msr[TS] set, since the TM structures are still invalid, thus avoiding doing TM operations for in-kernel exceptions and possible process reschedule. With this patch, the MSR[TS] will only be set just before recheckpointing and setting TEXASR[FS] = 1, thus avoiding an interrupt with TM registers in invalid state. Other than that, if CONFIG_PREEMPT is set, there might be a preemption just after setting MSR[TS] and before tm_recheckpoint(), thus, this block must be atomic from a preemption perspective, thus, calling preempt_disable/enable() on this code. It is not possible to move tm_recheckpoint to happen earlier, because it is required to get the checkpointed registers from userspace, with __get_user(), thus, the only way to avoid this undesired behavior is delaying the MSR[TS] set. The 32-bits signal handler seems to be safe this current issue, but, it might be exposed to the preemption issue, thus, disabling preemption in this chunk of code. Changes from v2: * Run the critical section with preempt_disable. Fixes: 87b4e539 ("powerpc/tm: Fix return of active 64bit signals") Cc: stable@vger.kernel.org (v3.9+) Signed-off-by:
Breno Leitao <leitao@debian.org> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Ard Biesheuvel authored
commit 3bbd3db8 upstream. readelf complains about the section layout of vmlinux when building with CONFIG_RELOCATABLE=y (for KASLR): readelf: Warning: [21]: Link field (0) should index a symtab section. readelf: Warning: [21]: Info field (0) should index a relocatable section. Also, it seems that our use of '-pie -shared' is contradictory, and thus ambiguous. In general, the way KASLR is wired up at the moment is highly tailored to how ld.bfd happens to implement (and conflate) PIE executables and shared libraries, so given the current effort to support other toolchains, let's fix some of these issues as well. - Drop the -pie linker argument and just leave -shared. In ld.bfd, the differences between them are unclear (except for the ELF type of the produced image [0]) but lld chokes on seeing both at the same time. - Rename the .rela output section to .rela.dyn, as is customary for shared libraries and PIE executables, so that it is not misidentified by readelf as a static relocation section (producing the warnings above). - Pass the -z notext and -z norelro options to explicitly instruct the linker to permit text relocations, and to omit the RELRO program header (which requires a certain section layout that we don't adhere to in the kernel). These are the defaults for current versions of ld.bfd. - Discard .eh_frame and .gnu.hash sections to avoid them from being emitted between .head.text and .text, screwing up the section layout. These changes only affect the ELF image, and produce the same binary image. [0] b9dce7f1 ("arm64: kernel: force ET_DYN ELF type for ...") Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Smith <peter.smith@linaro.org> Tested-by:
Nick Desaulniers <ndesaulniers@google.com> Signed-off-by:
Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by:
Will Deacon <will.deacon@arm.com> Signed-off-by:
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Ard Biesheuvel authored
commit dd6846d7 upstream. Commit 1212f7a1 ("scripts/kallsyms: filter arm64's __efistub_ symbols") updated the kallsyms code to filter out symbols with the __efistub_ prefix explicitly, so we no longer require the hack in our linker script to emit them as absolute symbols. Cc: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by:
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Ard Biesheuvel authored
commit 1212f7a1 upstream. On arm64, the EFI stub and the kernel proper are essentially the same binary, although the EFI stub executes at a different virtual address as the kernel. For this reason, the EFI stub is restricted in the symbols it can link to, which is ensured by prefixing all EFI stub symbols with __efistub_ (and emitting __efistub_ prefixed aliases for routines that may be shared between the core kernel and the stub) These symbols are leaking into kallsyms, polluting the namespace, so let's filter them explicitly. Signed-off-by:
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Benjamin Coddington authored
commit b8eee0e9 upstream. Commit 9d5b86ac ("fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks") specified that the l_pid returned for F_GETLK on a local file that has a remote lock should be the pid of the lock manager process. That commit, while updating other filesystems, failed to update lockd, such that locks created by lockd had their fl_pid set to that of the remote process holding the lock. Fix that here to be the pid of lockd. Also, fix the client case so that the returned lock pid is negative, which indicates a remote lock on a remote file. Fixes: 9d5b86ac ("fs/locks: Remove fl_nspid and use fs-specific...") Cc: stable@vger.kernel.org Signed-off-by:
Benjamin Coddington <bcodding@redhat.com> Signed-off-by:
J. Bruce Fields <bfields@redhat.com> Signed-off-by:
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Ondrej Mosnacek authored
commit 5df275cd upstream. Do the LE conversions before doing the Infiniband-related range checks. The incorrect checks are otherwise causing a failure to load any policy with an ibendportcon rule on BE systems. This can be reproduced by running (on e.g. ppc64): cat >my_module.cil <<EOF (type test_ibendport_t) (roletype object_r test_ibendport_t) (ibendportcon mlx4_0 1 (system_u object_r test_ibendport_t ((s0) (s0)))) EOF semodule -i my_module.cil Also, fix loading/storing the 64-bit subnet prefix for OCON_IBPKEY to use a correctly aligned buffer. Finally, do not use the 'nodebuf' (u32) buffer where 'buf' (__le32) should be used instead. Tested internally on a ppc64 machine with a RHEL 7 kernel with this patch applied. Cc: Daniel Jurgens <danielj@mellanox.com> Cc: Eli Cohen <eli@mellanox.com> Cc: James Morris <jmorris@namei.org> Cc: Doug Ledford <dledford@redhat.com> Cc: <stable@vger.kernel.org> # 4.13+ Fixes: a806f7a1 ("selinux: Create policydb version for Infiniband support") Signed-off-by:
Ondrej Mosnacek <omosnace@redhat.com> Acked-by:
Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by:
Paul Moore <paul@paul-moore.com> Signed-off-by:
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Larry Finger authored
commit 8ea3819c upstream. The cordic routine for calculating sines and cosines that was added in commit 6f98e62a ("b43: update cordic code to match current specs") contains an error whereby a quantity declared u32 can in fact go negative. This problem was detected by Priit Laes who is switching b43 to use the routine in the library functions of the kernel. Fixes: 98650454 ("b43: make cordic common (LP-PHY and N-PHY need it)") Reported-by:
Priit Laes <plaes@plaes.org> Cc: Rafał Miłecki <zajec5@gmail.com> Cc: Stable <stable@vger.kernel.org> # 2.6.34 Signed-off-by:
Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by:
Kalle Valo <kvalo@codeaurora.org> Signed-off-by:
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Andreas Gruenbacher authored
commit 2d29f6b9 upstream. Fix the resource group wrap-around logic in gfs2_rbm_find that commit e579ed4f broke. The bug can lead to unnecessary repeated scanning of the same bitmaps; there is a risk that future changes will turn this into an endless loop. Fixes: e579ed4f ("GFS2: Introduce rbm field bii") Cc: stable@vger.kernel.org # v3.13+ Signed-off-by:
Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by:
Bob Peterson <rpeterso@redhat.com> Signed-off-by:
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Andreas Gruenbacher authored
commit 6ff9b09e upstream. In gfs2_create_inode, after setting and releasing the acl / default_acl, the acl / default_acl pointers are not set to NULL as they should be. In that state, when the function reaches label fail_free_acls, gfs2_create_inode will try to release the same acls again. Fix that by setting the pointers to NULL after releasing the acls. Slightly simplify the logic. Also, posix_acl_release checks for NULL already, so there is no need to duplicate those checks here. Fixes: e01580bf ("gfs2: use generic posix ACL infrastructure") Reported-by:
Pan Bian <bianpan2016@163.com> Cc: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org # v4.9+ Signed-off-by:
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Vasily Averin authored
commit d47b41ac upstream. According to comment in dlm_user_request() ua should be freed in dlm_free_lkb() after successful attach to lkb. However ua is attached to lkb not in set_lock_args() but later, inside request_lock(). Fixes 597d0cae ("[DLM] dlm: user locks") Cc: stable@kernel.org # 2.6.19 Signed-off-by:
Vasily Averin <vvs@virtuozzo.com> Signed-off-by:
David Teigland <teigland@redhat.com> Signed-off-by:
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Vasily Averin authored
commit c0174726 upstream. Fixes 6d40c4a7 ("dlm: improve error and debug messages") Cc: stable@kernel.org # 3.5 Signed-off-by:
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Vasily Averin authored
commit 23851e97 upstream. Fixes 3d6aa675 ("dlm: keep lkbs in idr") Cc: stable@kernel.org # 3.1 Signed-off-by:
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Vasily Averin authored
commit b982896c upstream. If allocation fails on last elements of array need to free already allocated elements. v2: just move existing out_rsbtbl label to right place Fixes 789924ba635f ("dlm: fix race between remove and lookup") Cc: stable@kernel.org # 3.6 Signed-off-by:
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Hui Peng authored
commit cbb2ebf7 upstream. In `create_composite_quirk`, the terminating condition of for loops is `quirk->ifnum < 0`. So any composite quirks should end with `struct snd_usb_audio_quirk` object with ifnum < 0. for (quirk = quirk_comp->data; quirk->ifnum >= 0; ++quirk) { ..... } the data field of Bower's & Wilkins PX headphones usb device device quirks do not end with {.ifnum = -1}, wihch may result in out-of-bound read. This Patch fix the bug by adding an ending quirk object. Fixes: 240a8af9 ("ALSA: usb-audio: Add a quirck for B&W PX headphones") Signed-off-by:
Hui Peng <benquike@163.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
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Takashi Iwai authored
commit f4351a19 upstream. The parser for the processing unit reads bNrInPins field before the bLength sanity check, which may lead to an out-of-bound access when a malformed descriptor is given. Fix it by assignment after the bLength check. Cc: <stable@vger.kernel.org> Signed-off-by:
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Dan Carpenter authored
commit 1524f4e4 upstream. The "chip->dsp_spos_instance" can be NULL on some of the ealier error paths in snd_cs46xx_create(). Reported-by:
"Yavuz, Tuba" <tuba@ece.ufl.edu> Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Damien Le Moal authored
commit d57f9da8 upstream. struct bioctx includes the ref refcount_t to track the number of I/O fragments used to process a target BIO as well as ensure that the zone of the BIO is kept in the active state throughout the lifetime of the BIO. However, since decrementing of this reference count is done in the target .end_io method, the function bio_endio() must be called multiple times for read and write target BIOs, which causes problems with the value of the __bi_remaining struct bio field for chained BIOs (e.g. the clone BIO passed by dm core is large and splits into fragments by the block layer), resulting in incorrect values and inconsistencies with the BIO_CHAIN flag setting. This is turn triggers the BUG_ON() call: BUG_ON(atomic_read(&bio->__bi_remaining) <= 0); in bio_remaining_done() called from bio_endio(). Fix this ensuring that bio_endio() is called only once for any target BIO by always using internal clone BIOs for processing any read or write target BIO. This allows reference counting using the target BIO context counter to trigger the target BIO completion bio_endio() call once all data, metadata and other zone work triggered by the BIO complete. Overall, this simplifies the code too as the target .end_io becomes unnecessary and differences between read and write BIO issuing and completion processing disappear. Fixes: 3b1a94c8 ("dm zoned: drive-managed zoned block device target") Cc: stable@vger.kernel.org Signed-off-by:
Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by:
Mike Snitzer <snitzer@redhat.com> Signed-off-by:
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Mikulas Patocka authored
commit e4b069e0 upstream. Since commit d1ac3ff0 ("dm verity: switch to using asynchronous hash crypto API") dm-verity uses asynchronous crypto calls for verification, so that it can use hardware with asynchronous processing of crypto operations. These asynchronous calls don't support vmalloc memory, but the buffer data can be allocated with vmalloc if dm-bufio is short of memory and uses a reserved buffer that was preallocated in dm_bufio_client_create(). Fix verity_hash_update() so that it deals with vmalloc'd memory correctly. Reported-by:
"Xiao, Jin" <jin.xiao@intel.com> Signed-off-by:
Mikulas Patocka <mpatocka@redhat.com> Fixes: d1ac3ff0 ("dm verity: switch to using asynchronous hash crypto API") Cc: stable@vger.kernel.org # 4.12+ Signed-off-by:
Sudip Mukherjee <sudipm.mukherjee@gmail.com> Acked-by:
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Stefan Hajnoczi authored
commit a72b69dc upstream. The vhost_vsock->guest_cid field is uninitialized when /dev/vhost-vsock is opened until the VHOST_VSOCK_SET_GUEST_CID ioctl is called. kvmalloc(..., GFP_KERNEL | __GFP_RETRY_MAYFAIL) does not zero memory. All other vhost_vsock fields are initialized explicitly so just initialize this field too. Signed-off-by:
Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by:
Michael S. Tsirkin <mst@redhat.com> Cc: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by:
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Joel Stanley authored
commit e213574a upstream. We cannot build these files with clang as it does not allow altivec instructions in assembly when -msoft-float is passed. Jinsong Ji <jji@us.ibm.com> wrote: > We currently disable Altivec/VSX support when enabling soft-float. So > any usage of vector builtins will break. > > Enable Altivec/VSX with soft-float may need quite some clean up work, so > I guess this is currently a limitation. > > Removing -msoft-float will make it work (and we are lucky that no > floating point instructions will be generated as well). This is a workaround until the issue is resolved in clang. Link: https://bugs.llvm.org/show_bug.cgi?id=31177 Link: https://github.com/ClangBuiltLinux/linux/issues/239Signed-off-by:
Joel Stanley <joel@jms.id.au> Reviewed-by:
Nathan Chancellor <natechancellor@gmail.com> Signed-off-by:
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Joel Stanley authored
commit 813af51f upstream. Clang needs to be told which target it is building for when cross compiling. Link: https://github.com/ClangBuiltLinux/linux/issues/259Signed-off-by:
Masahiro Yamada <yamada.masahiro@socionext.com> [nc: Use 'ifeq ($(cc-name),clang)' instead of 'ifdef CONFIG_CC_IS_CLANG' because that config does not exist in 4.14; the Kconfig rewrite that added that config happened in 4.18] Signed-off-by:
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Joel Stanley authored
commit 3bd98050 upstream. The powerpc makefile will use these in it's boot wrapper. Signed-off-by:
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Masahiro Yamada authored
commit 238bcbc4 upstream. Collect basic Clang options such as --target, --prefix, --gcc-toolchain, -no-integrated-as into a single variable CLANG_FLAGS so that it can be easily reused in other parts of Makefile. Signed-off-by:
Greg Hackmann <ghackmann@google.com> Signed-off-by:
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Masahiro Yamada authored
commit dbe27a00 upstream. We are still a way off the Clang's integrated assembler support for the kernel. Hence, -no-integrated-as is mandatory to build the kernel with Clang. If you had an ancient version of Clang that does not recognize this option, you would not be able to compile the kernel anyway. Signed-off-by:
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Matthias Kaehlcke authored
commit 584ed9fa upstream. The raid10 driver can't be built with clang since it uses a variable length array in a structure (VLAIS): drivers/md/raid10.c:4583:17: error: fields must have a constant size: 'variable length array in structure' extension will never be supported Allocate the r10bio struct with kmalloc instead of using the VLAIS construct. Shaohua: set the MD_RECOVERY_INTR bit Neil Brown: use GFP_NOIO Signed-off-by:
Matthias Kaehlcke <mka@chromium.org> Reviewed-by:
Guenter Roeck <groeck@chromium.org> Signed-off-by:
Shaohua Li <shli@fb.com> Signed-off-by:
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Joel Stanley authored
When building to record the mcount locations the kernel uses KBUILD_CFLAGS but not KBUILD_CPPFLAGS. This means it lacks -Qunused-arguments when building with clang, resulting in a lot of noisy warnings. Signed-off-by:
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Joel Stanley authored
commit aea44714 upstream. The powerpc kernel uses setjmp which causes a warning when building with clang: In file included from arch/powerpc/xmon/xmon.c:51: ./arch/powerpc/include/asm/setjmp.h:15:13: error: declaration of built-in function 'setjmp' requires inclusion of the header <setjmp.h> [-Werror,-Wbuiltin-requires-header] extern long setjmp(long *); ^ ./arch/powerpc/include/asm/setjmp.h:16:13: error: declaration of built-in function 'longjmp' requires inclusion of the header <setjmp.h> [-Werror,-Wbuiltin-requires-header] extern void longjmp(long *, long); ^ This *is* the header and we're not using the built-in setjump but rather the one in arch/powerpc/kernel/misc.S. As the compiler warning does not make sense, it for the files where setjmp is used. Signed-off-by:
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Nicholas Piggin authored
commit 6977f95e upstream. Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Reviewed-by:
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Vasily Averin authored
commit b8be5674 upstream. Signed-off-by:
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Vasily Averin authored
commit 4ecd55ea upstream. After commit d202cce8, an expired cache_head can be removed from the cache_detail's hash. However, the expired cache_head may be waiting for a reply from a previously submitted request. Such a cache_head has an increased refcounter and therefore it won't be freed after cache_put(freeme). Because the cache_head was removed from the hash it cannot be found during cache_clean() and can be leaked forever, together with stalled cache_request and other taken resources. In our case we noticed it because an entry in the export cache was holding a reference on a filesystem. Fixes d202cce8 ("sunrpc: never return expired entries in sunrpc_cache_lookup") Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Cc: stable@kernel.org # 2.6.35 Signed-off-by:
NeilBrown <neilb@suse.com> Signed-off-by:
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Huang Ying authored
commit 7af7a8e1 upstream. KSM pages may be mapped to the multiple VMAs that cannot be reached from one anon_vma. So during swapin, a new copy of the page need to be generated if a different anon_vma is needed, please refer to comments of ksm_might_need_to_copy() for details. During swapoff, unuse_vma() uses anon_vma (if available) to locate VMA and virtual address mapped to the page, so not all mappings to a swapped out KSM page could be found. So in try_to_unuse(), even if the swap count of a swap entry isn't zero, the page needs to be deleted from swap cache, so that, in the next round a new page could be allocated and swapin for the other mappings of the swapped out KSM page. But this contradicts with the THP swap support. Where the THP could be deleted from swap cache only after the swap count of every swap entry in the huge swap cluster backing the THP has reach 0. So try_to_unuse() is changed in commit e0709829 ("mm, THP, swap: support to reclaim swap space for THP swapped out") to check that before delete a page from swap cache, but this has broken KSM swapoff too. Fortunately, KSM is for the normal pages only, so the original behavior for KSM pages could be restored easily via checking PageTransCompound(). That is how this patch works. The bug is introduced by e0709829 ("mm, THP, swap: support to reclaim swap space for THP swapped out"), which is merged by v4.14-rc1. So I think we should backport the fix to from 4.14 on. But Hugh thinks it may be rare for the KSM pages being in the swap device when swapoff, so nobody reports the bug so far. Link: http://lkml.kernel.org/r/20181226051522.28442-1-ying.huang@intel.com Fixes: e0709829 ("mm, THP, swap: support to reclaim swap space for THP swapped out") Signed-off-by:
"Huang, Ying" <ying.huang@intel.com> Reported-by:
Hugh Dickins <hughd@google.com> Tested-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Dan Williams authored
commit 02917e9f upstream. At Maintainer Summit, Greg brought up a topic I proposed around EXPORT_SYMBOL_GPL usage. The motivation was considerations for when EXPORT_SYMBOL_GPL is warranted and the criteria for taking the exceptional step of reclassifying an existing export. Specifically, I wanted to make the case that although the line is fuzzy and hard to specify in abstract terms, it is nonetheless clear that devm_memremap_pages() and HMM (Heterogeneous Memory Management) have crossed it. The devm_memremap_pages() facility should have been EXPORT_SYMBOL_GPL from the beginning, and HMM as a derivative of that functionality should have naturally picked up that designation as well. Contrary to typical rules, the HMM infrastructure was merged upstream with zero in-tree consumers. There was a promise at the time that those users would be merged "soon", but it has been over a year with no drivers arriving. While the Nouveau driver is about to belatedly make good on that promise it is clear that HMM was targeted first and foremost at an out-of-tree consumer. HMM is derived from devm_memremap_pages(), a facility Christoph and I spearheaded to support persistent memory. It combines a device lifetime model with a dynamically created 'struct page' / memmap array for any physical address range. It enables coordination and control of the many code paths in the kernel built to interact with memory via 'struct page' objects. With HMM the integration goes even deeper by allowing device drivers to hook and manipulate page fault and page free events. One interpretation of when EXPORT_SYMBOL is suitable is when it is exporting stable and generic leaf functionality. The devm_memremap_pages() facility continues to see expanding use cases, peer-to-peer DMA being the most recent, with no clear end date when it will stop attracting reworks and semantic changes. It is not suitable to export devm_memremap_pages() as a stable 3rd party driver API due to the fact that it is still changing and manipulates core behavior. Moreover, it is not in the best interest of the long term development of the core memory management subsystem to permit any external driver to effectively define its own system-wide memory management policies with no encouragement to engage with upstream. I am also concerned that HMM was designed in a way to minimize further engagement with the core-MM. That, with these hooks in place, device-drivers are free to implement their own policies without much consideration for whether and how the core-MM could grow to meet that need. Going forward not only should HMM be EXPORT_SYMBOL_GPL, but the core-MM should be allowed the opportunity and stimulus to change and address these new use cases as first class functionality. Original changelog: hmm_devmem_add(), and hmm_devmem_add_resource() duplicated devm_memremap_pages() and are now simple now wrappers around the core facility to inject a dev_pagemap instance into the global pgmap_radix and hook page-idle events. The devm_memremap_pages() interface is base infrastructure for HMM. HMM has more and deeper ties into the kernel memory management implementation than base ZONE_DEVICE which is itself a EXPORT_SYMBOL_GPL facility. Originally, the HMM page structure creation routines copied the devm_memremap_pages() code and reused ZONE_DEVICE. A cleanup to unify the implementations was discussed during the initial review: http://lkml.iu.edu/hypermail/linux/kernel/1701.2/00812.html Recent work to extend devm_memremap_pages() for the peer-to-peer-DMA facility enabled this cleanup to move forward. In addition to the integration with devm_memremap_pages() HMM depends on other GPL-only symbols: mmu_notifier_unregister_no_release percpu_ref region_intersects __class_create It goes further to consume / indirectly expose functionality that is not exported to any other driver: alloc_pages_vma walk_page_range HMM is derived from devm_memremap_pages(), and extends deep core-kernel fundamentals. Similar to devm_memremap_pages(), mark its entry points EXPORT_SYMBOL_GPL(). [logang@deltatee.com: PCI/P2PDMA: match interface changes to devm_memremap_pages()] Link: http://lkml.kernel.org/r/20181130225911.2900-1-logang@deltatee.com Link: http://lkml.kernel.org/r/154275560565.76910.15919297436557795278.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by:
Dan Williams <dan.j.williams@intel.com> Signed-off-by:
Logan Gunthorpe <logang@deltatee.com> Reviewed-by:
Christoph Hellwig <hch@lst.de> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com>, Cc: Michal Hocko <mhocko@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: <stable@vger.kernel.org> Signed-off-by:
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Dan Williams authored
commit 58ef15b7 upstream. devm semantics arrange for resources to be torn down when device-driver-probe fails or when device-driver-release completes. Similar to devm_memremap_pages() there is no need to support an explicit remove operation when the users properly adhere to devm semantics. Note that devm_kzalloc() automatically handles allocating node-local memory. Link: http://lkml.kernel.org/r/154275559545.76910.9186690723515469051.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by:
Jérôme Glisse <jglisse@redhat.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Dan Williams authored
commit 06489cfb upstream. Given the fact that devm_memremap_pages() requires a percpu_ref that is torn down by devm_memremap_pages_release() the current support for mapping RAM is broken. Support for remapping "System RAM" has been broken since the beginning and there is no existing user of this this code path, so just kill the support and make it an explicit error. This cleanup also simplifies a follow-on patch to fix the error path when setting a devm release action for devm_memremap_pages_release() fails. Link: http://lkml.kernel.org/r/154275557997.76910.14689813630968180480.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by:
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Dan Williams authored
commit 808153e1 upstream. devm_memremap_pages() is a facility that can create struct page entries for any arbitrary range and give drivers the ability to subvert core aspects of page management. Specifically the facility is tightly integrated with the kernel's memory hotplug functionality. It injects an altmap argument deep into the architecture specific vmemmap implementation to allow allocating from specific reserved pages, and it has Linux specific assumptions about page structure reference counting relative to get_user_pages() and get_user_pages_fast(). It was an oversight and a mistake that this was not marked EXPORT_SYMBOL_GPL from the outset. Again, devm_memremap_pagex() exposes and relies upon core kernel internal assumptions and will continue to evolve along with 'struct page', memory hotplug, and support for new memory types / topologies. Only an in-kernel GPL-only driver is expected to keep up with this ongoing evolution. This interface, and functionality derived from this interface, is not suitable for kernel-external drivers. Link: http://lkml.kernel.org/r/154275557457.76910.16923571232582744134.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by:
Michal Hocko <mhocko@suse.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Michal Hocko authored
commit b15c8726 upstream. We have received a bug report that an injected MCE about faulty memory prevents memory offline to succeed on 4.4 base kernel. The underlying reason was that the HWPoison page has an elevated reference count and the migration keeps failing. There are two problems with that. First of all it is dubious to migrate the poisoned page because we know that accessing that memory is possible to fail. Secondly it doesn't make any sense to migrate a potentially broken content and preserve the memory corruption over to a new location. Oscar has found out that 4.4 and the current upstream kernels behave slightly differently with his simply testcase === int main(void) { int ret; int i; int fd; char *array = malloc(4096); char *array_locked = malloc(4096); fd = open("/tmp/data", O_RDONLY); read(fd, array, 4095); for (i = 0; i < 4096; i++) array_locked[i] = 'd'; ret = mlock((void *)PAGE_ALIGN((unsigned long)array_locked), sizeof(array_locked)); if (ret) perror("mlock"); sleep (20); ret = madvise((void *)PAGE_ALIGN((unsigned long)array_locked), 4096, MADV_HWPOISON); if (ret) perror("madvise"); for (i = 0; i < 4096; i++) array_locked[i] = 'd'; return 0; } === + offline this memory. In 4.4 kernels he saw the hwpoisoned page to be returned back to the LRU list kernel: [<ffffffff81019ac9>] dump_trace+0x59/0x340 kernel: [<ffffffff81019e9a>] show_stack_log_lvl+0xea/0x170 kernel: [<ffffffff8101ac71>] show_stack+0x21/0x40 kernel: [<ffffffff8132bb90>] dump_stack+0x5c/0x7c kernel: [<ffffffff810815a1>] warn_slowpath_common+0x81/0xb0 kernel: [<ffffffff811a275c>] __pagevec_lru_add_fn+0x14c/0x160 kernel: [<ffffffff811a2eed>] pagevec_lru_move_fn+0xad/0x100 kernel: [<ffffffff811a334c>] __lru_cache_add+0x6c/0xb0 kernel: [<ffffffff81195236>] add_to_page_cache_lru+0x46/0x70 kernel: [<ffffffffa02b4373>] extent_readpages+0xc3/0x1a0 [btrfs] kernel: [<ffffffff811a16d7>] __do_page_cache_readahead+0x177/0x200 kernel: [<ffffffff811a18c8>] ondemand_readahead+0x168/0x2a0 kernel: [<ffffffff8119673f>] generic_file_read_iter+0x41f/0x660 kernel: [<ffffffff8120e50d>] __vfs_read+0xcd/0x140 kernel: [<ffffffff8120e9ea>] vfs_read+0x7a/0x120 kernel: [<ffffffff8121404b>] kernel_read+0x3b/0x50 kernel: [<ffffffff81215c80>] do_execveat_common.isra.29+0x490/0x6f0 kernel: [<ffffffff81215f08>] do_execve+0x28/0x30 kernel: [<ffffffff81095ddb>] call_usermodehelper_exec_async+0xfb/0x130 kernel: [<ffffffff8161c045>] ret_from_fork+0x55/0x80 And that latter confuses the hotremove path because an LRU page is attempted to be migrated and that fails due to an elevated reference count. It is quite possible that the reuse of the HWPoisoned page is some kind of fixed race condition but I am not really sure about that. With the upstream kernel the failure is slightly different. The page doesn't seem to have LRU bit set but isolate_movable_page simply fails and do_migrate_range simply puts all the isolated pages back to LRU and therefore no progress is made and scan_movable_pages finds same set of pages over and over again. Fix both cases by explicitly checking HWPoisoned pages before we even try to get reference on the page, try to unmap it if it is still mapped. As explained by Naoya: : Hwpoison code never unmapped those for no big reason because : Ksm pages never dominate memory, so we simply didn't have strong : motivation to save the pages. Also put WARN_ON(PageLRU) in case there is a race and we can hit LRU HWPoison pages which shouldn't happen but I couldn't convince myself about that. Naoya has noted the following: : Theoretically no such gurantee, because try_to_unmap() doesn't have a : guarantee of success and then memory_failure() returns immediately : when hwpoison_user_mappings fails. : Or the following code (comes after hwpoison_user_mappings block) also impli= : es : that the target page can still have PageLRU flag. : : /* : * Torn down by someone else? : */ : if (PageLRU(p) && !PageSwapCache(p) && p->mapping =3D=3D NULL) { : action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED); : res =3D -EBUSY; : goto out; : } : : So I think it's OK to keep "if (WARN_ON(PageLRU(page)))" block in : current version of your patch. Link: http://lkml.kernel.org/r/20181206120135.14079-1-mhocko@kernel.orgSigned-off-by:
Oscar Salvador <osalvador@suse.com> Debugged-by:
David Hildenbrand <david@redhat.com> Acked-by:
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Minchan Kim authored
commit 5547932d upstream. If blkdev_get fails, we shouldn't do blkdev_put. Otherwise, kernel emits below log. This patch fixes it. WARNING: CPU: 0 PID: 1893 at fs/block_dev.c:1828 blkdev_put+0x105/0x120 Modules linked in: CPU: 0 PID: 1893 Comm: swapoff Not tainted 4.19.0+ #453 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 RIP: 0010:blkdev_put+0x105/0x120 Call Trace: __x64_sys_swapoff+0x46d/0x490 do_syscall_64+0x5a/0x190 entry_SYSCALL_64_after_hwframe+0x49/0xbe irq event stamp: 4466 hardirqs last enabled at (4465): __free_pages_ok+0x1e3/0x490 hardirqs last disabled at (4466): trace_hardirqs_off_thunk+0x1a/0x1c softirqs last enabled at (3420): __do_softirq+0x333/0x446 softirqs last disabled at (3407): irq_exit+0xd1/0xe0 Link: http://lkml.kernel.org/r/20181127055429.251614-3-minchan@kernel.orgSigned-off-by:
Minchan Kim <minchan@kernel.org> Reviewed-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by:
Joey Pabalinas <joeypabalinas@gmail.com> Cc: <stable@vger.kernel.org> [4.14+] Signed-off-by:
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David Herrmann authored
commit 7b558513 upstream. This changes the fork(2) syscall to record the process start_time after initializing the basic task structure but still before making the new process visible to user-space. Technically, we could record the start_time anytime during fork(2). But this might lead to scenarios where a start_time is recorded long before a process becomes visible to user-space. For instance, with userfaultfd(2) and TLS, user-space can delay the execution of fork(2) for an indefinite amount of time (and will, if this causes network access, or similar). By recording the start_time late, it much closer reflects the point in time where the process becomes live and can be observed by other processes. Lastly, this makes it much harder for user-space to predict and control the start_time they get assigned. Previously, user-space could fork a process and stall it in copy_thread_tls() before its pid is allocated, but after its start_time is recorded. This can be misused to later-on cycle through PIDs and resume the stalled fork(2) yielding a process that has the same pid and start_time as a process that existed before. This can be used to circumvent security systems that identify processes by their pid+start_time combination. Even though user-space was always aware that start_time recording is flaky (but several projects are known to still rely on start_time-based identification), changing the start_time to be recorded late will help mitigate existing attacks and make it much harder for user-space to control the start_time a process gets assigned. Reported-by:
Jann Horn <jannh@google.com> Signed-off-by:
Tom Gundersen <teg@jklm.no> Signed-off-by:
David Herrmann <dh.herrmann@gmail.com> Signed-off-by:
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