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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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13
arch/x86/include/asm/desc.h
View file

@ -291,11 +291,24 @@ static inline unsigned long get_desc_base(const struct desc_struct *desc)
return desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24);
}
static inline void set_desc_base(struct desc_struct *desc, unsigned long base)
{
desc->base0 = base & 0xffff;
desc->base1 = (base >> 16) & 0xff;
desc->base2 = (base >> 24) & 0xff;
}
static inline unsigned long get_desc_limit(const struct desc_struct *desc)
{
return desc->limit0 | (desc->limit << 16);
}
static inline void set_desc_limit(struct desc_struct *desc, unsigned long limit)
{
desc->limit0 = limit & 0xffff;
desc->limit = (limit >> 16) & 0xf;
}
static inline void _set_gate(int gate, unsigned type, void *addr,
unsigned dpl, unsigned ist, unsigned seg)
{

4
arch/x86/include/asm/stackprotector.h
View file

@ -90,9 +90,7 @@ static inline void setup_stack_canary_segment(int cpu)
struct desc_struct desc;
desc = gdt_table[GDT_ENTRY_STACK_CANARY];
desc.base0 = canary & 0xffff;
desc.base1 = (canary >> 16) & 0xff;
desc.base2 = (canary >> 24) & 0xff;
set_desc_base(&desc, canary);
write_gdt_entry(gdt_table, GDT_ENTRY_STACK_CANARY, &desc, DESCTYPE_S);
#endif
}

27
arch/x86/include/asm/system.h
View file

@ -150,33 +150,6 @@ do { \
#endif
#ifdef __KERNEL__
#define _set_base(addr, base) do { unsigned long __pr; \
__asm__ __volatile__ ("movw %%dx,%1\n\t" \
"rorl $16,%%edx\n\t" \
"movb %%dl,%2\n\t" \
"movb %%dh,%3" \
:"=&d" (__pr) \
:"m" (*((addr)+2)), \
"m" (*((addr)+4)), \
"m" (*((addr)+7)), \
"0" (base) \
); } while (0)
#define _set_limit(addr, limit) do { unsigned long __lr; \
__asm__ __volatile__ ("movw %%dx,%1\n\t" \
"rorl $16,%%edx\n\t" \
"movb %2,%%dh\n\t" \
"andb $0xf0,%%dh\n\t" \
"orb %%dh,%%dl\n\t" \
"movb %%dl,%2" \
:"=&d" (__lr) \
:"m" (*(addr)), \
"m" (*((addr)+6)), \
"0" (limit) \
); } while (0)
#define set_base(ldt, base) _set_base(((char *)&(ldt)) , (base))
#define set_limit(ldt, limit) _set_limit(((char *)&(ldt)) , ((limit)-1))
extern void native_load_gs_index(unsigned);

18
arch/x86/kernel/apm_32.c
View file

@ -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);

21
drivers/pnp/pnpbios/bioscalls.c
View file

@ -55,9 +55,9 @@ __asm__(".text \n"
#define Q2_SET_SEL(cpu, selname, address, size) \
do { \
struct desc_struct *gdt = get_cpu_gdt_table((cpu)); \
set_base(gdt[(selname) >> 3], (u32)(address)); \
set_limit(gdt[(selname) >> 3], size); \
struct desc_struct *gdt = get_cpu_gdt_table((cpu)); \
set_desc_base(&gdt[(selname) >> 3], (u32)(address)); \
set_desc_limit(&gdt[(selname) >> 3], (size) - 1); \
} while(0)
static struct desc_struct bad_bios_desc;
@ -479,16 +479,17 @@ void pnpbios_calls_init(union pnp_bios_install_struct *header)
bad_bios_desc.a = 0;
bad_bios_desc.b = 0x00409200;
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));
for_each_possible_cpu(i) {
struct desc_struct *gdt = get_cpu_gdt_table(i);
if (!gdt)
continue;
set_base(gdt[GDT_ENTRY_PNPBIOS_CS32], &pnp_bios_callfunc);
set_base(gdt[GDT_ENTRY_PNPBIOS_CS16],
__va(header->fields.pm16cseg));
set_base(gdt[GDT_ENTRY_PNPBIOS_DS],
__va(header->fields.pm16dseg));
set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_CS32],
(unsigned long)&pnp_bios_callfunc);
set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_CS16],
(unsigned long)__va(header->fields.pm16cseg));
set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_DS],
(unsigned long)__va(header->fields.pm16dseg));
}
}