bisecting fixing commit since 0319b848b155185815724e1b46103c550627a845
building syzkaller on d236a457274375e5273ac4e958722659929c469f
testing commit 0319b848b155185815724e1b46103c550627a845
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: eaab42751bcb0f6696ad278b3528afb6e039f9b47fbc6bc37853ebdefe6e9ff1
run #0: crashed: general protection fault in rcu_segcblist_enqueue
run #1: OK
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
reproducer seems to be flaky
testing current HEAD 60a9483534ed0d99090a2ee1d4bb0b8179195f51
testing commit 60a9483534ed0d99090a2ee1d4bb0b8179195f51
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: c603c2f082f61421a0845568ed976e25798e883f598bb4e1bc05656588115061
all runs: OK
# git bisect start 60a9483534ed0d99090a2ee1d4bb0b8179195f51 0319b848b155185815724e1b46103c550627a845
Bisecting: 1409 revisions left to test after this (roughly 11 steps)
[4a86d41404005a3c7e7b6065e8169ac6202887a9] perf tools: Allow build-id with trailing zeros

testing commit 4a86d41404005a3c7e7b6065e8169ac6202887a9
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 5a7f60768cd1c65875444b7fa9cca2abc255544bb72ed365df6dfe00523d7829
run #0: OK
run #1: OK
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: boot failed: KFENCE: use-after-free in kvm_fastop_exception
# git bisect bad 4a86d41404005a3c7e7b6065e8169ac6202887a9
Bisecting: 671 revisions left to test after this (roughly 10 steps)
[626bf91a292e2035af5b9d9cce35c5c138dfe06d] Merge tag 'net-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

testing commit 626bf91a292e2035af5b9d9cce35c5c138dfe06d
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: aea0135815c70be65711413dff65cf5463f23fdecb70ebc9e895f2010ea4e2c8
all runs: OK
# git bisect bad 626bf91a292e2035af5b9d9cce35c5c138dfe06d
Bisecting: 378 revisions left to test after this (roughly 9 steps)
[5e6a5845dd651b00754a62edec2f0a439182024d] Merge tag 'gpio-updates-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

testing commit 5e6a5845dd651b00754a62edec2f0a439182024d
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 308e2302235fffc17267b4e32d5cdbec25600aa777cada8033c5bb7acdffba36
run #0: crashed: BUG: spinlock bad magic in synchronize_srcu
run #1: OK
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
# git bisect good 5e6a5845dd651b00754a62edec2f0a439182024d
Bisecting: 156 revisions left to test after this (roughly 8 steps)
[e99314a340d27efafab3b7ea226beb239162cd46] Merge tag 'kvmarm-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

testing commit e99314a340d27efafab3b7ea226beb239162cd46
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: eacb425775a0bcb9ead8e2e559aeddf6afb20a96863081679a12f1754063060d
all runs: OK
# git bisect bad e99314a340d27efafab3b7ea226beb239162cd46
Bisecting: 110 revisions left to test after this (roughly 7 steps)
[0176ec51290f8ef543a8c18a02e932d6ccedbbc5] KVM: stats: Update doc for histogram statistics

testing commit 0176ec51290f8ef543a8c18a02e932d6ccedbbc5
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: dfd9678c85d24545970851d0bc8ea6e12c3f8f4e49e7e97f681385e8d73a6eb5
all runs: OK
# git bisect bad 0176ec51290f8ef543a8c18a02e932d6ccedbbc5
Bisecting: 55 revisions left to test after this (roughly 6 steps)
[84ec8d2d539f7286d4504c2d377002f1ea7458d6] KVM: VMX: Smush x2APIC MSR bitmap adjustments into single function

testing commit 84ec8d2d539f7286d4504c2d377002f1ea7458d6
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 0a942c23e84b16ae278a173ef8dea2b55d8fbb37df97b160de7b9e1768e3c1f6
all runs: OK
# git bisect bad 84ec8d2d539f7286d4504c2d377002f1ea7458d6
Bisecting: 27 revisions left to test after this (roughly 5 steps)
[0214f6bbe564632adba299e38023d681c1bd68c5] KVM: x86: Migrate the PIT only if vcpu0 is migrated, not any BSP

testing commit 0214f6bbe564632adba299e38023d681c1bd68c5
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 3d0b5a37800dc5a3e24a0c3ceebb7e3c65a372c6bbc612913b3811eb77a2eee1
all runs: OK
# git bisect bad 0214f6bbe564632adba299e38023d681c1bd68c5
Bisecting: 13 revisions left to test after this (roughly 4 steps)
[c5c8c7c53004cb70715320018c3b4287071c1cfd] KVM: x86/mmu: Make walk_shadow_page_lockless_{begin,end} interoperate with the TDP MMU

testing commit c5c8c7c53004cb70715320018c3b4287071c1cfd
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 7d796439aea987349d84e67ad62c94d63d681f26d19e7cf1a98e0421a0488524
run #0: crashed: BUG: spinlock bad magic in synchronize_srcu
run #1: OK
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
# git bisect good c5c8c7c53004cb70715320018c3b4287071c1cfd
Bisecting: 6 revisions left to test after this (roughly 3 steps)
[2a24be79b6b7061a486239c3a3489eb67b9587f6] KVM: VMX: Set EDX at INIT with CPUID.0x1, Family-Model-Stepping

testing commit 2a24be79b6b7061a486239c3a3489eb67b9587f6
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 39292547db89e0f1edd86af8ccce002eba02c7f6322070cfb3b2e65da8331dcf
run #0: crashed: BUG: sleeping function called from invalid context in lock_sock_nested
run #1: OK
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
# git bisect good 2a24be79b6b7061a486239c3a3489eb67b9587f6
Bisecting: 3 revisions left to test after this (roughly 2 steps)
[61152cd907d59ffd6b0a9479b2fa3b3b7b080409] KVM: VMX: Remove explicit MMU reset in enter_rmode()

testing commit 61152cd907d59ffd6b0a9479b2fa3b3b7b080409
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: cc378526ef832ae7891eaf33dd1add9c9557af92176509699660225cdd0fadf4
all runs: OK
# git bisect bad 61152cd907d59ffd6b0a9479b2fa3b3b7b080409
Bisecting: 0 revisions left to test after this (roughly 1 step)
[665f4d9238ad83c36dd4e078ccab45b3ddec211d] KVM: SVM: Fall back to KVM's hardcoded value for EDX at RESET/INIT

testing commit 665f4d9238ad83c36dd4e078ccab45b3ddec211d
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 7f4e50321edadf323ca3cb4657ede37f8c03a3a5100e2977fb4fab7b7c841bd8
all runs: OK
# git bisect bad 665f4d9238ad83c36dd4e078ccab45b3ddec211d
Bisecting: 0 revisions left to test after this (roughly 0 steps)
[067a456d091d05fdae32cae350410d905968b645] KVM: SVM: Require exact CPUID.0x1 match when stuffing EDX at INIT

testing commit 067a456d091d05fdae32cae350410d905968b645
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 34dde558ececbd02e8fa5e2f6b0d55708d7fb13bb2e1729d33cab30ec5fe6d56
all runs: OK
# git bisect bad 067a456d091d05fdae32cae350410d905968b645
067a456d091d05fdae32cae350410d905968b645 is the first bad commit
commit 067a456d091d05fdae32cae350410d905968b645
Author: Sean Christopherson <seanjc@google.com>
Date:   Tue Jul 13 09:32:43 2021 -0700

    KVM: SVM: Require exact CPUID.0x1 match when stuffing EDX at INIT
    
    Do not allow an inexact CPUID "match" when querying the guest's CPUID.0x1
    to stuff EDX during INIT.  In the common case, where the guest CPU model
    is an AMD variant, allowing an inexact match is a nop since KVM doesn't
    emulate Intel's goofy "out-of-range" logic for AMD and Hygon.  If the
    vCPU model happens to be an Intel variant, an inexact match is possible
    if and only if the max CPUID leaf is precisely '0'. Aside from the fact
    that there's probably no CPU in existence with a single CPUID leaf, if
    the max CPUID leaf is '0', that means that CPUID.0.EAX is '0', and thus
    an inexact match for CPUID.0x1.EAX will also yield '0'.
    
    So, with lots of twisty logic, no functional change intended.
    
    Reviewed-by: Reiji Watanabe <reijiw@google.com>
    Signed-off-by: Sean Christopherson <seanjc@google.com>
    Message-Id: <20210713163324.627647-6-seanjc@google.com>
    Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

 arch/x86/kvm/svm/svm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

culprit signature: 34dde558ececbd02e8fa5e2f6b0d55708d7fb13bb2e1729d33cab30ec5fe6d56
parent  signature: 39292547db89e0f1edd86af8ccce002eba02c7f6322070cfb3b2e65da8331dcf
Reproducer flagged being flaky
revisions tested: 14, total time: 3h49m10.03381186s (build: 1h36m52.373688005s, test: 2h10m53.129881946s)
first good commit: 067a456d091d05fdae32cae350410d905968b645 KVM: SVM: Require exact CPUID.0x1 match when stuffing EDX at INIT
recipients (to): ["pbonzini@redhat.com" "reijiw@google.com" "seanjc@google.com"]
recipients (cc): []