On 05/01/2018 07:31 AM, David Laight wrote:
From: Boris Ostrovsky
Sent: 30 April 2018 17:24
To: linux-kernel@xxxxxxxxxxxxxxx; xen-devel@xxxxxxxxxxxxxxxxxxxx
Cc: jgross@xxxxxxxx; Boris Ostrovsky; stable@xxxxxxxxxxxxxxx
Subject: [PATCH 1/4] xen/PVH: Replace GDT_ENTRY with explicit constant
Latest binutils release (2.29.1) will no longer allow proper computation
of GDT entries on 32-bits, with warning:
arch/x86/xen/xen-pvh.S: Assembler messages:
arch/x86/xen/xen-pvh.S:150: Warning: shift count out of range (32 is not between 0 and 31)
arch/x86/xen/xen-pvh.S:150: Warning: shift count out of range (40 is not between 0 and 31)
arch/x86/xen/xen-pvh.S:150: Warning: shift count out of range (32 is not between 0 and 31)
arch/x86/xen/xen-pvh.S:152: Warning: shift count out of range (32 is not between 0 and 31)
arch/x86/xen/xen-pvh.S:152: Warning: shift count out of range (40 is not between 0 and 31)
arch/x86/xen/xen-pvh.S:152: Warning: shift count out of range (32 is not between 0 and 31)
Use explicit value of the entry instead of using GDT_ENTRY() macro.
...
#ifdef CONFIG_X86_64
- .quad GDT_ENTRY(0xa09a, 0, 0xfffff) /* __KERNEL_CS */
+ .quad 0x00af9a000000ffff /* __BOOT_CS */
#else
- .quad GDT_ENTRY(0xc09a, 0, 0xfffff) /* __KERNEL_CS */
+ .quad 0x00cf9a000000ffff /* __BOOT_CS */
#endif
- .quad GDT_ENTRY(0xc092, 0, 0xfffff) /* __KERNEL_DS */
+ .quad 0x00cf92000000ffff /* __BOOT_DS */
gdt_end:
It has to be possible to fix the GDT_ENTRY() macro.
Even if you end up with one that generates two 32bit values.
Is it worth it though? We seem to be using GDT_ENTRY_INIT() everywhere
and the only other reference that I see is in pm.c and it also probably
ought to use GDT_ENTRY_INIT().
You've also changed the name in the comments.
Yes, I should mention this in the commit message.
-boris
