On Thu, Dec 28, 2017 at 12:33:22PM +0300, Alexander Tsoy wrote: > Hello, > > 4.14.9 fails to boot if CONFIG_MCORE2 is enabled and when compiled with > gcc 6+. More details in the following bug reports: > https://bugzilla.kernel.org/show_bug.cgi?id=198263 > https://bugs.gentoo.org/642268 > > I bisected it to the commit below: > > $ git bisect good > 2bc9fa0beaf10206a778f02e9e5cb62f50345b1a is the first bad commit > commit 2bc9fa0beaf10206a778f02e9e5cb62f50345b1a > Author: Andy Lutomirski <luto@xxxxxxxxxx> > Date: Mon Dec 4 15:07:23 2017 +0100 > > x86/entry/64: Use a per-CPU trampoline stack for IDT entries > > commit 7f2590a110b837af5679d08fc25c6227c5a8c497 upstream. > > Historically, IDT entries from usermode have always gone directly > to the running task's kernel stack. Rearrange it so that we enter > on > a per-CPU trampoline stack and then manually switch to the task's > stack. > This touches a couple of extra cachelines, but it gives us a chance > to run some code before we touch the kernel stack. > > The asm isn't exactly beautiful, but I think that fully refactoring > it can wait. > > Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx> > Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Reviewed-by: Borislav Petkov <bp@xxxxxxx> > Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxxxx> > Cc: Borislav Petkov <bpetkov@xxxxxxx> > Cc: Brian Gerst <brgerst@xxxxxxxxx> > Cc: Dave Hansen <dave.hansen@xxxxxxxxx> > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > Cc: David Laight <David.Laight@xxxxxxxxxx> > Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx> > Cc: Eduardo Valentin <eduval@xxxxxxxxxx> > Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: H. Peter Anvin <hpa@xxxxxxxxx> > Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> > Cc: Juergen Gross <jgross@xxxxxxxx> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Rik van Riel <riel@xxxxxxxxxx> > Cc: Will Deacon <will.deacon@xxxxxxx> > Cc: aliguori@xxxxxxxxxx > Cc: daniel.gruss@xxxxxxxxxxxxxx > Cc: hughd@xxxxxxxxxx > Cc: keescook@xxxxxxxxxx > Link: https://lkml.kernel.org/r/20171204150606.225330557@linutronix > .de > Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > :040000 040000 275d4746936a9e521a2b5041856f7dc1d1820dc6 > 8f8e869fd59c3dd781dceffa76e53e41d733a0cf M arch > > $ git bisect log > git bisect start > # bad: [dad5c1402c570cd07a80113784bc20a7f930c8ae] Linux 4.14.9 > git bisect bad dad5c1402c570cd07a80113784bc20a7f930c8ae > # good: [7b3775017f4e6b87dfd2c7f63d1eaf057948f31d] Linux 4.14.8 > git bisect good 7b3775017f4e6b87dfd2c7f63d1eaf057948f31d > # good: [d120cd749ef9770ee98b708a83b49547dcf1c0e1] x86/entry/64: > Separate cpu_current_top_of_stack from TSS.sp0 > git bisect good d120cd749ef9770ee98b708a83b49547dcf1c0e1 > # bad: [97f41b41c432e5a80c91445d92c2f4b729984d36] powerpc/xmon: Avoid > tripping SMP hardlockup watchdog > git bisect bad 97f41b41c432e5a80c91445d92c2f4b729984d36 > # bad: [bfd66a406fe7e590055c1d6714adc697f18664c8] PCI: Avoid bus reset > if bridge itself is broken > git bisect bad bfd66a406fe7e590055c1d6714adc697f18664c8 > # bad: [8388d287e361a2fd0a39bece30a736d692d5c3d8] x86/cpufeatures: Make > CPU bugs sticky > git bisect bad 8388d287e361a2fd0a39bece30a736d692d5c3d8 > # bad: [bb568391775d4a840992e2d2493f39d6e86401e3] x86/entry/64: Move > the IST stacks into struct cpu_entry_area > git bisect bad bb568391775d4a840992e2d2493f39d6e86401e3 > # bad: [2bc9fa0beaf10206a778f02e9e5cb62f50345b1a] x86/entry/64: Use a > per-CPU trampoline stack for IDT entries > git bisect bad 2bc9fa0beaf10206a778f02e9e5cb62f50345b1a > # good: [c3dbef1bd0f7eb09daf49409ea533aa1b0eeb82e] x86/espfix/64: Stop > assuming that pt_regs is on the entry stack > git bisect good c3dbef1bd0f7eb09daf49409ea533aa1b0eeb82e > # first bad commit: [2bc9fa0beaf10206a778f02e9e5cb62f50345b1a] > x86/entry/64: Use a per-CPU trampoline stack for IDT entries Thanks for letting us know. Does Linus's current tree also have this same problem for you? greg k-h