Commit 57594742 authored by Akinobu Mita's avatar Akinobu Mita Committed by Ingo Molnar
Browse files

x86: Introduce set_desc_base() and set_desc_limit() 



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: default avatarAkinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090718151105.GC11294@localhost.localdomain>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent fde0312d

arch/x86/include/asm/desc.h

+13 −0
Original line number Diff line number Diff line
@@ -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)

{

arch/x86/include/asm/stackprotector.h

+1 −3
Original line number Diff line number Diff line
@@ -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

}

arch/x86/include/asm/system.h

+0 −27
Original line number Diff line number Diff line
@@ -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);

arch/x86/kernel/apm_32.c

+9 −9
Original line number Diff line number Diff line
@@ -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);

drivers/pnp/pnpbios/bioscalls.c

+11 −10
Original line number Diff line number Diff line
@@ -56,8 +56,8 @@ __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); \

	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));

	}

}

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