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2017-09-28objtool: Support unoptimized frame pointer setupJosh Poimboeuf
Arnd Bergmann reported a bunch of warnings like: crypto/jitterentropy.o: warning: objtool: jent_fold_time()+0x3b: call without frame pointer save/setup crypto/jitterentropy.o: warning: objtool: jent_stuck()+0x1d: call without frame pointer save/setup crypto/jitterentropy.o: warning: objtool: jent_unbiased_bit()+0x15: call without frame pointer save/setup crypto/jitterentropy.o: warning: objtool: jent_read_entropy()+0x32: call without frame pointer save/setup crypto/jitterentropy.o: warning: objtool: jent_entropy_collector_free()+0x19: call without frame pointer save/setup and arch/x86/events/core.o: warning: objtool: collect_events uses BP as a scratch register arch/x86/events/core.o: warning: objtool: events_ht_sysfs_show()+0x22: call without frame pointer save/setup With certain rare configurations, GCC sometimes sets up the frame pointer with: lea (%rsp),%rbp instead of: mov %rsp,%rbp The instructions are equivalent, so treat the former like the latter. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a468af8b28a69b83fffc6d7668be9b6fcc873699.1506526584.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-28objtool: Skip unreachable warnings for GCC 4.4 and olderJosh Poimboeuf
The kbuild bot occasionally reports warnings like: drivers/scsi/pcmcia/aha152x_core.o: warning: objtool: seldo_run()+0x130: unreachable instruction These warnings are always with GCC 4.4. That version of GCC sometimes places unreachable instructions after calls to noreturn functions. The unreachable warnings aren't very important anyway. Just ignore them for old versions of GCC. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/bc89b807d965b98ec18a0bb94f96a594bd58f2f2.1506551639.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-27Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull quota and isofs fixes from Jan Kara: "Two quota fixes (fallout of the quota locking changes) and an isofs build fix" * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: quota: Fix quota corruption with generic/232 test isofs: fix build regression quota: add missing lock into __dquot_transfer()
2017-09-27Merge tag 'linux-kselftest-4.14-rc3-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest Pull kselftest fixes from Shuah Khan: "This update consists of: - fixes to several existing tests - a test for regression introduced by b9470c27607b ("inet: kill smallest_size and smallest_port") - seccomp support for glibc 2.26 siginfo_t.h - fixes to kselftest framework and tests to run make O=dir use-case - fixes to silence unnecessary test output to de-clutter test results" * tag 'linux-kselftest-4.14-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (28 commits) selftests: timers: set-timer-lat: Fix hang when testing unsupported alarms selftests: timers: set-timer-lat: fix hang when std out/err are redirected selftests/memfd: correct run_tests.sh permission selftests/seccomp: Support glibc 2.26 siginfo_t.h selftests: futex: Makefile: fix for loops in targets to run silently selftests: Makefile: fix for loops in targets to run silently selftests: mqueue: Use full path to run tests from Makefile selftests: futex: copy sub-dir test scripts for make O=dir run selftests: lib.mk: copy test scripts and test files for make O=dir run selftests: sync: kselftest and kselftest-clean fail for make O=dir case selftests: sync: use TEST_CUSTOM_PROGS instead of TEST_PROGS selftests: lib.mk: add TEST_CUSTOM_PROGS to allow custom test run/install selftests: watchdog: fix to use TEST_GEN_PROGS and remove clean selftests: lib.mk: fix test executable status check to use full path selftests: Makefile: clear LDFLAGS for make O=dir use-case selftests: lib.mk: kselftest and kselftest-clean fail for make O=dir case Makefile: kselftest and kselftest-clean fail for make O=dir case selftests/net: msg_zerocopy enable build with older kernel headers selftests: actually run the various net selftests selftest: add a reuseaddr test ...
2017-09-27Merge branch 'x86-fpu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fpu fixes and cleanups from Ingo Molnar: "This is _way_ more cleanups than fixes, but the bugs were subtle and hard to hit, and the primary reason for them existing was the unnecessary historical complexity of some of the x86/fpu interfaces. The first bunch of commits clean up and simplify the xstate user copy handling functions, in reaction to the collective head-scratching about the xstate user-copy handling code that leads up to the fix for this SkyLake xstate handling bug: 0852b374173b: x86/fpu: Add FPU state copying quirk to handle XRSTOR failure on Intel Skylake CPUs The cleanups don't change any functionality, they just (hopefully) make it all clearer, more consistent, more debuggable and more robust. Note that most of the linecount increase comes from these commits, where we better split the user/kernel copy logic by having more variants, instead repeated fragile patterns of: if (kbuf) { memcpy(kbuf + pos, data, copy); } else { if (__copy_to_user(ubuf + pos, data, copy)) return -EFAULT; } The next bunch of commits simplify the FPU state-machine to get rid of old lazy-FPU idiosyncrasies - a defensive simplification to make all the code easier to review and fix. No change in functionality. Then there's a couple of additional debugging tweaks: static checker warning fix and move an FPU related warning to under WARN_ON_FPU(), followed by another bunch of commits that represent a finegrained split-up of the fixes from Eric Biggers to handle weird xstate bits properly. I did this finegrained split-up because some of these fixes also impact the ABI for weird xstate handling, for which we'd like to have good bisection results, should they cause any problems. (We also had one regression with the more monolithic fixes, so splitting it all up sounded prudent for robustness reasons as well.) About the whole series: the commits up to 03eaec81ac09 have been in -next for months - but I've recently rebased them to remove a state machine clean-up commit that was objected to, and to make it more bisectable - so technically it's a new, rebased tree. Robustness history: this series had some regressions along the way, and all reported regressions have been fixed. All but one of the regressions manifested itself as easy to report warnings. The previous version of this latest series was also in linux-next, with one (warning-only) regression reported which is fixed in the latest version. Barring last minute brown paper bag bugs (and the commits are now older by a day which I'd hope helps paperbag reduction), I'm reasonably confident about its general robustness. Famous last words ..." * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits) x86/fpu: Use using_compacted_format() instead of open coded X86_FEATURE_XSAVES x86/fpu: Use validate_xstate_header() to validate the xstate_header in copy_user_to_xstate() x86/fpu: Eliminate the 'xfeatures' local variable in copy_user_to_xstate() x86/fpu: Copy the full header in copy_user_to_xstate() x86/fpu: Use validate_xstate_header() to validate the xstate_header in copy_kernel_to_xstate() x86/fpu: Eliminate the 'xfeatures' local variable in copy_kernel_to_xstate() x86/fpu: Copy the full state_header in copy_kernel_to_xstate() x86/fpu: Use validate_xstate_header() to validate the xstate_header in __fpu__restore_sig() x86/fpu: Use validate_xstate_header() to validate the xstate_header in xstateregs_set() x86/fpu: Introduce validate_xstate_header() x86/fpu: Rename fpu__activate_fpstate_read/write() to fpu__prepare_[read|write]() x86/fpu: Rename fpu__activate_curr() to fpu__initialize() x86/fpu: Simplify and speed up fpu__copy() x86/fpu: Fix stale comments about lazy FPU logic x86/fpu: Rename fpu::fpstate_active to fpu::initialized x86/fpu: Remove fpu__current_fpstate_write_begin/end() x86/fpu: Fix fpu__activate_fpstate_read() and update comments x86/fpu: Reinitialize FPU registers if restoring FPU state fails x86/fpu: Don't let userspace set bogus xcomp_bv x86/fpu: Turn WARN_ON() in context switch into WARN_ON_FPU() ...
2017-09-27quota: Fix quota corruption with generic/232 testJan Kara
Eric has reported that since commit d2faa415166b "quota: Do not acquire dqio_sem for dquot overwrites in v2 format" test generic/232 occasionally fails due to quota information being incorrect. Indeed that commit was too eager to remove dqio_sem completely from the path that just overwrites quota structure with updated information. Although that is innocent on its own, another process that inserts new quota structure to the same block can perform read-modify-write cycle of that block thus effectively discarding quota information update if they race in a wrong way. Fix the problem by acquiring dqio_sem for reading for overwrites of quota structure. Note that it *is* possible to completely avoid taking dqio_sem in the overwrite path however that will require modifying path inserting / deleting quota structures to avoid RMW cycles of the full block and for now it is not clear whether it is worth the hassle. Fixes: d2faa415166b2883428efa92f451774ef44373ac Reported-and-tested-by: Eric Whitney <enwlinux@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-09-26Merge tag 'mmc-v4.14-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc Pull MMC fixes from Ulf Hansson: - sdhci-pci: Fix voltage switch for some Intel host controllers - tmio: remove broken and noisy debug macro * tag 'mmc-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: mmc: sdhci-pci: Fix voltage switch for some Intel host controllers mmc: tmio: remove broken and noisy debug macro
2017-09-26vfs: Return -ENXIO for negative SEEK_HOLE / SEEK_DATA offsetsAndreas Gruenbacher
In generic_file_llseek_size, return -ENXIO for negative offsets as well as offsets beyond EOF. This affects filesystems which don't implement SEEK_HOLE / SEEK_DATA internally, possibly because they don't support holes. Fixes xfstest generic/448. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-26Merge branch 'WIP.x86/fpu' into x86/fpu, because it's readyIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Use using_compacted_format() instead of open coded X86_FEATURE_XSAVESEric Biggers
This is the canonical method to use. Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-11-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Use validate_xstate_header() to validate the xstate_header in ↵Eric Biggers
copy_user_to_xstate() Tighten the checks in copy_user_to_xstate(). Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-10-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Eliminate the 'xfeatures' local variable in copy_user_to_xstate()Eric Biggers
We now have this field in hdr.xfeatures. Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-9-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Copy the full header in copy_user_to_xstate()Eric Biggers
This is in preparation to verify the full xstate header as supplied by user-space. Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-8-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Use validate_xstate_header() to validate the xstate_header in ↵Eric Biggers
copy_kernel_to_xstate() Tighten the checks in copy_kernel_to_xstate(). Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-7-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Eliminate the 'xfeatures' local variable in copy_kernel_to_xstate()Eric Biggers
We have this information in the xstate_header. Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-6-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Copy the full state_header in copy_kernel_to_xstate()Eric Biggers
This is in preparation to verify the full xstate header as supplied by user-space. Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-5-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Use validate_xstate_header() to validate the xstate_header in ↵Eric Biggers
__fpu__restore_sig() Tighten the checks in __fpu__restore_sig() and update comments. Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-4-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Use validate_xstate_header() to validate the xstate_header in ↵Eric Biggers
xstateregs_set() Tighten the checks in xstateregs_set(). Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-3-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Introduce validate_xstate_header()Eric Biggers
Move validation of user-supplied xstate_header into a helper function, in preparation of calling it from both the ptrace and sigreturn syscall paths. The new function also considers it to be an error if *any* reserved bits are set, whereas before we were just clearing most of them silently. This should reduce the chance of bugs that fail to correctly validate user-supplied XSAVE areas. It also will expose any broken userspace programs that set the other reserved bits; this is desirable because such programs will lose compatibility with future CPUs and kernels if those bits are ever used for anything. (There shouldn't be any such programs, and in fact in the case where the compacted format is in use we were already validating xfeatures. But you never know...) Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-2-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Rename fpu__activate_fpstate_read/write() to ↵Ingo Molnar
fpu__prepare_[read|write]() As per the new nomenclature we don't 'activate' the FPU state anymore, we initialize it. So drop the _activate_fpstate name from these functions, which were a bit of a mouthful anyway, and name them: fpu__prepare_read() fpu__prepare_write() Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Rename fpu__activate_curr() to fpu__initialize()Ingo Molnar
Rename this function to better express that it's all about initializing the FPU state of a task which goes hand in hand with the fpu::initialized field. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-33-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Simplify and speed up fpu__copy()Ingo Molnar
fpu__copy() has a preempt_disable()/enable() pair, which it had to do to be able to atomically unlazy the current task when doing an FNSAVE. But we don't unlazy tasks anymore, we always do direct saves/restores of FPU context. So remove both the unnecessary critical section, and update the comments. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-32-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Fix stale comments about lazy FPU logicIngo Molnar
We don't do any lazy restore anymore, what we have are two pieces of optimization: - no-FPU tasks that don't save/restore the FPU context (kernel threads are such) - cached FPU registers maintained via the fpu->last_cpu field. This means that if an FPU task context switches to a non-FPU task then we can maintain the FPU registers as an in-FPU copies (cache), and skip the restoration of them once we switch back to the original FPU-using task. Update all the comments that still referred to old 'lazy' and 'unlazy' concepts. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-31-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Rename fpu::fpstate_active to fpu::initializedIngo Molnar
The x86 FPU code used to have a complex state machine where both the FPU registers and the FPU state context could be 'active' (or inactive) independently of each other - which enabled features like lazy FPU restore. Much of this complexity is gone in the current code: now we basically can have FPU-less tasks (kernel threads) that don't use (and save/restore) FPU state at all, plus full FPU users that save/restore directly with no laziness whatsoever. But the fpu::fpstate_active still carries bits of the old complexity - meanwhile this flag has become a simple flag that shows whether the FPU context saving area in the thread struct is initialized and used, or not. Rename it to fpu::initialized to express this simplicity in the name as well. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-30-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Remove fpu__current_fpstate_write_begin/end()Ingo Molnar
These functions are not used anymore, so remove them. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Bobby Powers <bobbypowers@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-29-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-26x86/fpu: Fix fpu__activate_fpstate_read() and update commentsIngo Molnar
fpu__activate_fpstate_read() can be called for the current task when coredumping - or for stopped tasks when ptrace-ing. Implement this properly in the code and update the comments. This also fixes an incorrect (but harmless) warning introduced by one of the earlier patches. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-28-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-25Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull compat fix from Al Viro: "I really wish gcc warned about conversions from pointer to function into void *..." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix a typo in put_compat_shm_info()
2017-09-25fix a typo in put_compat_shm_info()Al Viro
"uip" misspelled as "up"; unfortunately, the latter happens to be a function and gcc is happy to convert it to void *... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-09-25Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: - Two sets of NVMe pull requests from Christoph: - Fixes for the Fibre Channel host/target to fix spec compliance - Allow a zero keep alive timeout - Make the debug printk for broken SGLs work better - Fix queue zeroing during initialization - Set of RDMA and FC fixes - Target div-by-zero fix - bsg double-free fix. - ndb unknown ioctl fix from Josef. - Buffered vs O_DIRECT page cache inconsistency fix. Has been floating around for a long time, well reviewed. From Lukas. - brd overflow fix from Mikulas. - Fix for a loop regression in this merge window, where using a union for two members of the loop_cmd turned out to be a really bad idea. From Omar. - Fix for an iostat regression fix in this series, using the wrong API to get at the block queue. From Shaohua. - Fix for a potential blktrace delection deadlock. From Waiman. * 'for-linus' of git://git.kernel.dk/linux-block: (30 commits) nvme-fcloop: fix port deletes and callbacks nvmet-fc: sync header templates with comments nvmet-fc: ensure target queue id within range. nvmet-fc: on port remove call put outside lock nvme-rdma: don't fully stop the controller in error recovery nvme-rdma: give up reconnect if state change fails nvme-core: Use nvme_wq to queue async events and fw activation nvme: fix sqhd reference when admin queue connect fails block: fix a crash caused by wrong API fs: Fix page cache inconsistency when mixing buffered and AIO DIO nvmet: implement valid sqhd values in completions nvme-fabrics: Allow 0 as KATO value nvme: allow timed-out ios to retry nvme: stop aer posting if controller state not live nvme-pci: Print invalid SGL only once nvme-pci: initialize queue memory before interrupts nvmet-fc: fix failing max io queue connections nvme-fc: use transport-specific sgl format nvme: add transport SGL definitions nvme.h: remove FC transport-specific error values ...
2017-09-25Merge tag 'gfs2-for-linus-4.14-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2 Pull gfs2 fix from Bob Peterson: "GFS2: Fix an old regression in GFS2's debugfs interface This fixes a regression introduced by commit 88ffbf3e037e ("GFS2: Use resizable hash table for glocks"). The regression caused the glock dump in debugfs to not report all the glocks, which makes debugging extremely difficult" * tag 'gfs2-for-linus-4.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: gfs2: Fix debugfs glocks dump
2017-09-25Merge tag 'microblaze-4.14-rc3' of git://git.monstr.eu/linux-2.6-microblazeLinus Torvalds
Pull Microblaze fixes from Michal Simek: - Kbuild fix - use vma_pages - setup default little endians * tag 'microblaze-4.14-rc3' of git://git.monstr.eu/linux-2.6-microblaze: arch: change default endian for microblaze microblaze: Cocci spatch "vma_pages" microblaze: Add missing kvm_para.h to Kbuild
2017-09-25Merge tag 'trace-v4.14-rc1-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Stack tracing and RCU has been having issues with each other and lockdep has been pointing out constant problems. The changes have been going into the stack tracer, but it has been discovered that the problem isn't with the stack tracer itself, but it is with calling save_stack_trace() from within the internals of RCU. The stack tracer is the one that can trigger the issue the easiest, but examining the problem further, it could also happen from a WARN() in the wrong place, or even if an NMI happened in this area and it did an rcu_read_lock(). The critical area is where RCU is not watching. Which can happen while going to and from idle, or bringing up or taking down a CPU. The final fix was to put the protection in kernel_text_address() as it is the one that requires RCU to be watching while doing the stack trace. To make this work properly, Paul had to allow rcu_irq_enter() happen after rcu_nmi_enter(). This should have been done anyway, since an NMI can page fault (reading vmalloc area), and a page fault triggers rcu_irq_enter(). One patch is just a consolidation of code so that the fix only needed to be done in one location" * tag 'trace-v4.14-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Remove RCU work arounds from stack tracer extable: Enable RCU if it is not watching in kernel_text_address() extable: Consolidate *kernel_text_address() functions rcu: Allow for page faults in NMI handlers
2017-09-25nvme-fcloop: fix port deletes and callbacksJames Smart
Now that there are potentially long delays between when a remoteport or targetport delete calls is made and when the callback occurs (dev_loss_tmo timeout), no longer block in the delete routines and move the final nport puts to the callbacks. Moved the fcloop_nport_get/put/free routines to avoid forward declarations. Ensure port_info structs used in registrations are nulled in case fields are not set (ex: devloss_tmo values). Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-25nvmet-fc: sync header templates with commentsJames Smart
Comments were incorrect: - defer_rcv was in host port template. moved to target port template - Added Mandatory statements for target port template items Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-25nvmet-fc: ensure target queue id within range.James Smart
When searching for queue id's ensure they are within the expected range. Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-25nvmet-fc: on port remove call put outside lockJames Smart
Avoid calling the put routine, as it may traverse to free routines while holding the target lock. Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-25nvme-rdma: don't fully stop the controller in error recoverySagi Grimberg
By calling nvme_stop_ctrl on a already failed controller will wait for the scan work to complete (only by identify timeout expiration which is 60 seconds). This is unnecessary when we already know that the controller has failed. Reported-by: Yi Zhang <yizhan@redhat.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-25nvme-rdma: give up reconnect if state change failsSagi Grimberg
If we failed to transition to state LIVE after a successful reconnect, then controller deletion already started. In this case there is no point moving forward with reconnect. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-25nvme-core: Use nvme_wq to queue async events and fw activationSagi Grimberg
async_event_work might race as it is executed from two different workqueues at the moment. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-25nvme: fix sqhd reference when admin queue connect failsJames Smart
Fix bug in sqhd patch. It wasn't the sq that was at risk. In the case where the admin queue connect command fails, the sq->size field is not set. Therefore, this becomes a divide by zero error. Add a quick check to bypass under this failure condition. Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-25gfs2: Fix debugfs glocks dumpAndreas Gruenbacher
The switch to rhashtables (commit 88ffbf3e03) broke the debugfs glock dump (/sys/kernel/debug/gfs2/<device>/glocks) for dumps bigger than a single buffer: the right function for restarting an rhashtable iteration from the beginning of the hash table is rhashtable_walk_enter; rhashtable_walk_stop + rhashtable_walk_start will just resume from the current position. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com> Cc: stable@vger.kernel.org # v4.3+
2017-09-25selftests: timers: set-timer-lat: Fix hang when testing unsupported alarmsShuah Khan
When timer_create() fails on a bootime or realtime clock, setup_timer() returns 0 as if timer has been set. Callers wait forever for the timer to expire. This hang is seen on a system that doesn't have support for: CLOCK_REALTIME_ALARM ABSTIME missing CAP_WAKE_ALARM? : [UNSUPPORTED] Test hangs waiting for a timer that hasn't been set to expire. Fix setup_timer() to return 1, add handling in callers to detect the unsupported case and return 0 without waiting to not fail the test. Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-09-25selftests: timers: set-timer-lat: fix hang when std out/err are redirectedShuah Khan
do_timer_oneshot() uses select() as a timer with FD_SETSIZE and readfs is cleared with FD_ZERO without FD_SET. When stdout and stderr are redirected, the test hangs in select forever. Fix the problem calling select() with readfds empty and nfds zero. This is sufficient for using select() for timer. With this fix "./set-timer-lat > /dev/null 2>&1" no longer hangs. Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> Acked-by: Greg Hackmann <ghackmann@google.com> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-09-25selftests/memfd: correct run_tests.sh permissionLi Zhijian
to fix the following issue: ------------------ TAP version 13 selftests: run_tests.sh ======================================== selftests: Warning: file run_tests.sh is not executable, correct this. not ok 1..1 selftests: run_tests.sh [FAIL] ------------------ Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-09-25selftests/seccomp: Support glibc 2.26 siginfo_t.hKees Cook
The 2.26 release of glibc changed how siginfo_t is defined, and the earlier work-around to using the kernel definition are no longer needed. The old way needs to stay around for a while, though. Reported-by: Seth Forshee <seth.forshee@canonical.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Shuah Khan <shuah@kernel.org> Cc: linux-kselftest@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-09-25selftests: futex: Makefile: fix for loops in targets to run silentlyShuah Khan
Fix for loops in targets to run silently to avoid cluttering the test results. Suppresses the following from targets: for DIR in functional; do \ BUILD_TARGET=./tools/testing/selftests/futex/$DIR; \ mkdir $BUILD_TARGET -p; \ make OUTPUT=$BUILD_TARGET -C $DIR all;\ done ./tools/testing/selftests/futex/run.sh Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> Reviewed-by: Darren Hart (VMware) <dvhart@infradead.org> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-09-25selftests: Makefile: fix for loops in targets to run silentlyShuah Khan
Fix for loops in targets to run silently to avoid cluttering the test results. Suppresses the following from targets: e.g run from breakpoints for TARGET in breakpoints; do \ BUILD_TARGET=$BUILD/$TARGET; \ mkdir $BUILD_TARGET -p; \ make OUTPUT=$BUILD_TARGET -C $TARGET;\ done; Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-09-25selftests: mqueue: Use full path to run tests from MakefileShuah Khan
Use full path including $(OUTPUT) to run tests from Makefile for normal case when objects reside in the source tree as well as when objects are relocated with make O=dir. In both cases $(OUTPUT) will be set correctly by lib.mk. Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-09-25selftests: futex: copy sub-dir test scripts for make O=dir runShuah Khan
For make O=dir run_tests to work, test scripts from sub-directories need to be copied over to the object directory. Running tests from the object directory is necessary to avoid making the source tree dirty. Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> Reviewed-by: Darren Hart (VMware) <dvhart@infradead.org> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-09-25block: fix a crash caused by wrong APIShaohua Li
part_stat_show takes a part device not a disk, so we should use part_to_disk. Fixes: d62e26b3ffd2("block: pass in queue to inflight accounting") Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Omar Sandoval <osandov@fb.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>