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* x86-tip.today (4cdf573)  early instaboot
@ 2018-04-10  8:12 Mike Galbraith
  2018-04-10  8:59 ` Ingo Molnar
  0 siblings, 1 reply; 6+ messages in thread
From: Mike Galbraith @ 2018-04-10  8:12 UTC (permalink / raw)
  To: Ingo Molnar; +Cc: LKML

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Hi Ingo,

FYI, my i4790 box reboots immediately.. or close enough to it that you
see nothing at all before again meeting the bios splash.  Master with
the ~same config works fine.  I haven't poked around yet (work).

	-Mike 

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: x86-tip.today (4cdf573)  early instaboot
  2018-04-10  8:12 x86-tip.today (4cdf573) early instaboot Mike Galbraith
@ 2018-04-10  8:59 ` Ingo Molnar
  2018-04-10 12:37   ` Mike Galbraith
  0 siblings, 1 reply; 6+ messages in thread
From: Ingo Molnar @ 2018-04-10  8:59 UTC (permalink / raw)
  To: Mike Galbraith; +Cc: Ingo Molnar, LKML, Thomas Gleixner, Peter Zijlstra


* Mike Galbraith <efault@gmx.de> wrote:

> Hi Ingo,
> 
> FYI, my i4790 box reboots immediately.. or close enough to it that you
> see nothing at all before again meeting the bios splash.  Master with
> the ~same config works fine.  I haven't poked around yet (work).

Hm, so there's been a few 'dangerous' pieces of work merged yesterday-ish.

Prime suspects would be:

 triton:~/tip> gll linus..x86/pti

 0564258fb2cf: x86/pti: Leave kernel text global for !PCID
 a5df4f1f0d78: x86/pti: Never implicitly clear _PAGE_GLOBAL for kernel image
 e0bb456e3250: x86/pti: Enable global pages for shared areas
 efad2b415152: x86/mm: Do not forbid _PAGE_RW before init for __ro_after_init
 4ddee6efdcd0: x86/mm: Comment _PAGE_GLOBAL mystery
 e71e836f463d: x86/mm: Remove extra filtering in pageattr code
 64c80759408f: x86/mm: Do not auto-massage page protections
 6baf4bec02db: x86/espfix: Document use of _PAGE_GLOBAL
 8a57f4849f4f: x86/mm: Introduce "default" kernel PTE mask
 606c7193d5fb: x86/mm: Undo double _PAGE_PSE clearing
 d1440b23c922: x86/mm: Factor out pageattr _PAGE_GLOBAL setting
 ee1400dda318: Merge branch 'linus' into x86/pti to pick up upstream changes
 071ccc966ba5: x86/entry/64: Drop idtentry's manual stack switch for user entries
 9820e1c3376c: x86/uapi: Fix asm/bootparam.h userspace compilation errors

... which you could test via 0564258fb2cf: if that insta-reboots too then 
9820e1c3376c^1 is expected to work and 4 bisection steps should pinpoint the 
guilty commit ...

But there's also the syscall rework:

 triton:~/tip> gll linus..x86/asm
 c76fc9826075: syscalls/x86: Adapt syscall_wrapper.h to the new syscall stub naming convention
 d5a00528b58c: syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()
 5ac9efa3c50d: syscalls/core, syscalls/x86: Clean up compat syscall stub naming convention
 e145242ea0df: syscalls/core, syscalls/x86: Clean up syscall stub naming convention
 6dc936f175cc: syscalls/x86: Extend register clearing on syscall entry to lower registers
 f8781c4a2263: syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64
 ebeb8c82ffaf: syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32
 7303e30ec1d8: syscalls/core: Prepare CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y for compat syscalls
 fa697140f9a2: syscalls/x86: Use 'struct pt_regs' based syscall calling convention for 64-bit syscalls
 1bd21c6c21e8: syscalls/core: Introduce CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y
 dfe64506c01e: x86/syscalls: Don't pointlessly reload the system call number

... which you could test via c76fc9826075: if that insta-reboots then 
dfe64506c01e^1 should be good and 4 bisection steps should suffice.

Thanks,

	Ingo

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: x86-tip.today (4cdf573)  early instaboot
  2018-04-10  8:59 ` Ingo Molnar
@ 2018-04-10 12:37   ` Mike Galbraith
  2018-04-10 14:06     ` Tom Lendacky
  0 siblings, 1 reply; 6+ messages in thread
From: Mike Galbraith @ 2018-04-10 12:37 UTC (permalink / raw)
  To: Ingo Molnar
  Cc: Ingo Molnar, LKML, Thomas Gleixner, Peter Zijlstra, Dave Hansen

On Tue, 2018-04-10 at 10:59 +0200, Ingo Molnar wrote:
> * Mike Galbraith <efault@gmx.de> wrote:
> 
> > Hi Ingo,
> > 
> > FYI, my i4790 box reboots immediately.. or close enough to it that you
> > see nothing at all before again meeting the bios splash.  Master with
> > the ~same config works fine.  I haven't poked around yet (work).
> 
> Hm, so there's been a few 'dangerous' pieces of work merged yesterday-ish.
> 
> Prime suspects would be:
> 
>  triton:~/tip> gll linus..x86/pti
> 
>  0564258fb2cf: x86/pti: Leave kernel text global for !PCID
>  a5df4f1f0d78: x86/pti: Never implicitly clear _PAGE_GLOBAL for kernel image
>  e0bb456e3250: x86/pti: Enable global pages for shared areas
>  efad2b415152: x86/mm: Do not forbid _PAGE_RW before init for __ro_after_init
>  4ddee6efdcd0: x86/mm: Comment _PAGE_GLOBAL mystery
>  e71e836f463d: x86/mm: Remove extra filtering in pageattr code
>  64c80759408f: x86/mm: Do not auto-massage page protections  <== WOOF
>  6baf4bec02db: x86/espfix: Document use of _PAGE_GLOBAL
>  8a57f4849f4f: x86/mm: Introduce "default" kernel PTE mask
>  606c7193d5fb: x86/mm: Undo double _PAGE_PSE clearing
>  d1440b23c922: x86/mm: Factor out pageattr _PAGE_GLOBAL setting
>  ee1400dda318: Merge branch 'linus' into x86/pti to pick up upstream changes
>  071ccc966ba5: x86/entry/64: Drop idtentry's manual stack switch for user entries
>  9820e1c3376c: x86/uapi: Fix asm/bootparam.h userspace compilation errors
> 
> ... which you could test via 0564258fb2cf: if that insta-reboots too then 
> 9820e1c3376c^1 is expected to work and 4 bisection steps should pinpoint the 
> guilty commit ...

Thanks.  I already had a full bisect running, so ended up doing more
than 4 steps, but ended up at the above.

	-Mike

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: x86-tip.today (4cdf573) early instaboot
  2018-04-10 12:37   ` Mike Galbraith
@ 2018-04-10 14:06     ` Tom Lendacky
  2018-04-10 15:48       ` Mike Galbraith
  0 siblings, 1 reply; 6+ messages in thread
From: Tom Lendacky @ 2018-04-10 14:06 UTC (permalink / raw)
  To: Mike Galbraith, Ingo Molnar
  Cc: Ingo Molnar, LKML, Thomas Gleixner, Peter Zijlstra, Dave Hansen

On 04/10/2018 07:37 AM, Mike Galbraith wrote:
> On Tue, 2018-04-10 at 10:59 +0200, Ingo Molnar wrote:
>> * Mike Galbraith <efault@gmx.de> wrote:
>>
>>> Hi Ingo,
>>>
>>> FYI, my i4790 box reboots immediately.. or close enough to it that you
>>> see nothing at all before again meeting the bios splash.  Master with
>>> the ~same config works fine.  I haven't poked around yet (work).
>>
>> Hm, so there's been a few 'dangerous' pieces of work merged yesterday-ish.
>>
>> Prime suspects would be:
>>
>>  triton:~/tip> gll linus..x86/pti
>>
>>  0564258fb2cf: x86/pti: Leave kernel text global for !PCID
>>  a5df4f1f0d78: x86/pti: Never implicitly clear _PAGE_GLOBAL for kernel image
>>  e0bb456e3250: x86/pti: Enable global pages for shared areas
>>  efad2b415152: x86/mm: Do not forbid _PAGE_RW before init for __ro_after_init
>>  4ddee6efdcd0: x86/mm: Comment _PAGE_GLOBAL mystery
>>  e71e836f463d: x86/mm: Remove extra filtering in pageattr code
>>  64c80759408f: x86/mm: Do not auto-massage page protections  <== WOOF
>>  6baf4bec02db: x86/espfix: Document use of _PAGE_GLOBAL
>>  8a57f4849f4f: x86/mm: Introduce "default" kernel PTE mask
>>  606c7193d5fb: x86/mm: Undo double _PAGE_PSE clearing
>>  d1440b23c922: x86/mm: Factor out pageattr _PAGE_GLOBAL setting
>>  ee1400dda318: Merge branch 'linus' into x86/pti to pick up upstream changes
>>  071ccc966ba5: x86/entry/64: Drop idtentry's manual stack switch for user entries
>>  9820e1c3376c: x86/uapi: Fix asm/bootparam.h userspace compilation errors
>>
>> ... which you could test via 0564258fb2cf: if that insta-reboots too then 
>> 9820e1c3376c^1 is expected to work and 4 bisection steps should pinpoint the 
>> guilty commit ...
> 
> Thanks.  I already had a full bisect running, so ended up doing more
> than 4 steps, but ended up at the above.

Just out of curiosity, can you try the following patch and see if it
fixes your reboot issue:

diff --git a/arch/x86/boot/compressed/kaslr.c
b/arch/x86/boot/compressed/kaslr.c
index c5196d2..a0a50b9 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -55,7 +55,7 @@
 extern unsigned long get_cmd_line_ptr(void);

 /* Used by PAGE_KERN* macros: */
-pteval_t __default_kernel_pte_mask __read_mostly;
+pteval_t __default_kernel_pte_mask __read_mostly = ~0;

 /* Simplified build-specific string for starting entropy. */
 static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"

Thanks,
Tom

> 
> 	-Mike
> 

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: x86-tip.today (4cdf573) early instaboot
  2018-04-10 14:06     ` Tom Lendacky
@ 2018-04-10 15:48       ` Mike Galbraith
  2018-04-12  7:09         ` Ingo Molnar
  0 siblings, 1 reply; 6+ messages in thread
From: Mike Galbraith @ 2018-04-10 15:48 UTC (permalink / raw)
  To: Tom Lendacky, Ingo Molnar
  Cc: Ingo Molnar, LKML, Thomas Gleixner, Peter Zijlstra, Dave Hansen

On Tue, 2018-04-10 at 09:06 -0500, Tom Lendacky wrote:
> 
> Just out of curiosity, can you try the following patch and see if it
> fixes your reboot issue:

Yup, all better.

> diff --git a/arch/x86/boot/compressed/kaslr.c
> b/arch/x86/boot/compressed/kaslr.c
> index c5196d2..a0a50b9 100644
> --- a/arch/x86/boot/compressed/kaslr.c
> +++ b/arch/x86/boot/compressed/kaslr.c
> @@ -55,7 +55,7 @@
>  extern unsigned long get_cmd_line_ptr(void);
> 
>  /* Used by PAGE_KERN* macros: */
> -pteval_t __default_kernel_pte_mask __read_mostly;
> +pteval_t __default_kernel_pte_mask __read_mostly = ~0;
> 
>  /* Simplified build-specific string for starting entropy. */
>  static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: x86-tip.today (4cdf573) early instaboot
  2018-04-10 15:48       ` Mike Galbraith
@ 2018-04-12  7:09         ` Ingo Molnar
  0 siblings, 0 replies; 6+ messages in thread
From: Ingo Molnar @ 2018-04-12  7:09 UTC (permalink / raw)
  To: Mike Galbraith, Dave Hansen, Arnd Bergmann, Tom Lendacky
  Cc: Tom Lendacky, Ingo Molnar, LKML, Thomas Gleixner, Peter Zijlstra,
	Dave Hansen


* Mike Galbraith <efault@gmx.de> wrote:

> On Tue, 2018-04-10 at 09:06 -0500, Tom Lendacky wrote:
> > 
> > Just out of curiosity, can you try the following patch and see if it
> > fixes your reboot issue:
> 
> Yup, all better.
> 
> > diff --git a/arch/x86/boot/compressed/kaslr.c
> > b/arch/x86/boot/compressed/kaslr.c
> > index c5196d2..a0a50b9 100644
> > --- a/arch/x86/boot/compressed/kaslr.c
> > +++ b/arch/x86/boot/compressed/kaslr.c
> > @@ -55,7 +55,7 @@
> >  extern unsigned long get_cmd_line_ptr(void);
> > 
> >  /* Used by PAGE_KERN* macros: */
> > -pteval_t __default_kernel_pte_mask __read_mostly;
> > +pteval_t __default_kernel_pte_mask __read_mostly = ~0;
> > 
> >  /* Simplified build-specific string for starting entropy. */
> >  static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"

Thanks guys!

I ended up back-merging this fix (and another fix) into:

  fb43d6cb91ef: x86/mm: Do not auto-massage page protections

I added credits as:

    - printk format warning fix from: Arnd Bergmann <arnd@arndb.de>
    - boot crash fix from:            Tom Lendacky <thomas.lendacky@amd.com>
    - crash bisected by:              Mike Galbraith <efault@gmx.de>

    ...
    
    Reported-and-fixed-by: Arnd Bergmann <arnd@arndb.de>
    Fixed-by: Tom Lendacky <thomas.lendacky@amd.com>
    Bisected-by: Mike Galbraith <efault@gmx.de>

Thanks,

	Ingo

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2018-04-12  7:09 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-04-10  8:12 x86-tip.today (4cdf573) early instaboot Mike Galbraith
2018-04-10  8:59 ` Ingo Molnar
2018-04-10 12:37   ` Mike Galbraith
2018-04-10 14:06     ` Tom Lendacky
2018-04-10 15:48       ` Mike Galbraith
2018-04-12  7:09         ` Ingo Molnar

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