Re: [PATCH char-misc 1/1] Drivers: hv: vmbus: Implement Direct Mode for stimer0

From: kbuild test robot
Date: Fri Nov 03 2017 - 18:55:30 EST


Hi Michael,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on char-misc/master]

url: https://github.com/0day-ci/linux/commits/mikelley-exchange-microsoft-com/Drivers-hv-vmbus-Implement-Direct-Mode-for-stimer0/20171103-214519
config: x86_64-randconfig-h0-11040619 (attached as .config)
compiler: gcc-4.9 (Debian 4.9.4-2) 4.9.4
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64

All warnings (new ones prefixed by >>):

In file included from include/linux/kasan.h:16:0,
from include/linux/slab.h:120,
from include/linux/irq.h:25,
from arch/x86/include/asm/mshyperv.h:7,
from arch/x86/entry/vdso/vdso32/../vclock_gettime.c:20,
from arch/x86/entry/vdso/vdso32/vclock_gettime.c:32:
arch/x86/include/asm/pgtable.h: In function 'pte_flags_pkey':
>> arch/x86/include/asm/pgtable.h:1199:2: warning: left shift count >= width of type
return (pte_flags & _PAGE_PKEY_MASK) >> _PAGE_BIT_PKEY_BIT0;
^
>> arch/x86/include/asm/pgtable.h:1199:2: warning: left shift count >= width of type
>> arch/x86/include/asm/pgtable.h:1199:2: warning: left shift count >= width of type
>> arch/x86/include/asm/pgtable.h:1199:2: warning: left shift count >= width of type
arch/x86/include/asm/pgtable.h:1199:2: warning: right shift count >= width of type

vim +1199 arch/x86/include/asm/pgtable.h

33a709b2 Dave Hansen 2016-02-12 1194
33a709b2 Dave Hansen 2016-02-12 1195 static inline u16 pte_flags_pkey(unsigned long pte_flags)
33a709b2 Dave Hansen 2016-02-12 1196 {
33a709b2 Dave Hansen 2016-02-12 1197 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
33a709b2 Dave Hansen 2016-02-12 1198 /* ifdef to avoid doing 59-bit shift on 32-bit values */
33a709b2 Dave Hansen 2016-02-12 @1199 return (pte_flags & _PAGE_PKEY_MASK) >> _PAGE_BIT_PKEY_BIT0;
33a709b2 Dave Hansen 2016-02-12 1200 #else
33a709b2 Dave Hansen 2016-02-12 1201 return 0;
33a709b2 Dave Hansen 2016-02-12 1202 #endif
33a709b2 Dave Hansen 2016-02-12 1203 }
33a709b2 Dave Hansen 2016-02-12 1204

:::::: The code at line 1199 was first introduced by commit
:::::: 33a709b25a760b91184bb335cf7d7c32b8123013 mm/gup, x86/mm/pkeys: Check VMAs and PTEs for protection keys

:::::: TO: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
:::::: CC: Ingo Molnar <mingo@xxxxxxxxxx>

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