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x86: Introduce set_desc_base() and set_desc_limit()

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Rename set_base()/set_limit to set_desc_base()/set_desc_limit()
and rewrite them in C. These are naturally introduced by the
idea of get_desc_base()/get_desc_limit().

The conversion actually found the bug in apm_32.c:
bad_bios_desc is written at run-time, but it is defined const
variable.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090718151105.GC11294@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Akinobu Mita
2009-07-19 00:11:06 +09:00
committed by Ingo Molnar
parent fde0312d01
commit 57594742a2
5 changed files with 34 additions and 49 deletions
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18
arch/x86/kernel/apm_32.c
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@@ -403,7 +403,7 @@ static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
static struct apm_user *user_list;
static DEFINE_SPINLOCK(user_list_lock);
static const struct desc_struct bad_bios_desc = { { { 0, 0x00409200 } } };
static struct desc_struct bad_bios_desc = { { { 0, 0x00409200 } } };
static const char driver_version[] = "1.16ac"; /* no spaces */
@@ -2337,8 +2337,8 @@ static int __init apm_init(void)
* This is for buggy BIOS's that refer to (real mode) segment 0x40
* even though they are called in protected mode.
*/
set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
_set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
set_desc_base(&bad_bios_desc, (unsigned long)__va(0x40UL << 4));
set_desc_limit(&bad_bios_desc, 4095 - (0x40 << 4));
/*
* Set up the long jump entry point to the APM BIOS, which is called
@@ -2358,12 +2358,12 @@ static int __init apm_init(void)
* code to that CPU.
*/
gdt = get_cpu_gdt_table(0);
set_base(gdt[APM_CS >> 3],
__va((unsigned long)apm_info.bios.cseg << 4));
set_base(gdt[APM_CS_16 >> 3],
__va((unsigned long)apm_info.bios.cseg_16 << 4));
set_base(gdt[APM_DS >> 3],
__va((unsigned long)apm_info.bios.dseg << 4));
set_desc_base(&gdt[APM_CS >> 3],
(unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
set_desc_base(&gdt[APM_CS_16 >> 3],
(unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
set_desc_base(&gdt[APM_DS >> 3],
(unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
proc_create("apm", 0, NULL, &apm_file_ops);