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x86: unify extable_{32|64}.c

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Introduce fixup_exception() on 64-bit and use it in kprobes to
eliminate an #ifdef.

Only 64-bit needs search_extable() due to a stepping bug.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Harvey Harrison 2008-01-30 13:31:41 +01:00 committed by Ingo Molnar
parent 46265df040
commit 6d48583ba9
6 changed files with 65 additions and 82 deletions
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12
arch/x86/kernel/kprobes.c
View file

@ -904,19 +904,9 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
* In case the user-specified fault handler returned
* zero, try to fix up.
*/
#ifdef CONFIG_X86_64
{
const struct exception_table_entry *fixup;
fixup = search_exception_tables(regs->ip);
if (fixup) {
regs->ip = fixup->fixup;
return 1;
}
}
#else
if (fixup_exception(regs))
return 1;
#endif
/*
* fixup routine could not handle it,
* Let do_page_fault() fix it.

2
arch/x86/mm/Makefile_32
View file

@ -2,7 +2,7 @@
# Makefile for the linux i386-specific parts of the memory manager.
#
obj-y := init_32.o pgtable_32.o fault_32.o ioremap_32.o extable_32.o pageattr_32.o mmap.o
obj-y := init_32.o pgtable_32.o fault_32.o ioremap_32.o extable.o pageattr_32.o mmap.o
obj-$(CONFIG_NUMA) += discontig_32.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o

2
arch/x86/mm/Makefile_64
View file

@ -2,7 +2,7 @@
# Makefile for the linux x86_64-specific parts of the memory manager.
#
obj-y := init_64.o fault_64.o ioremap_64.o extable_64.o pageattr_64.o mmap.o
obj-y := init_64.o fault_64.o ioremap_64.o extable.o pageattr_64.o mmap.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_NUMA) += numa_64.o
obj-$(CONFIG_K8_NUMA) += k8topology_64.o

62
arch/x86/mm/extable.c Normal file
View file

@ -0,0 +1,62 @@
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
int fixup_exception(struct pt_regs *regs)
{
const struct exception_table_entry *fixup;
#ifdef CONFIG_PNPBIOS
if (unlikely(SEGMENT_IS_PNP_CODE(regs->cs))) {
extern u32 pnp_bios_fault_eip, pnp_bios_fault_esp;
extern u32 pnp_bios_is_utter_crap;
pnp_bios_is_utter_crap = 1;
printk(KERN_CRIT "PNPBIOS fault.. attempting recovery.\n");
__asm__ volatile(
"movl %0, %%esp\n\t"
"jmp *%1\n\t"
: : "g" (pnp_bios_fault_esp), "g" (pnp_bios_fault_eip));
panic("do_trap: can't hit this");
}
#endif
fixup = search_exception_tables(regs->ip);
if (fixup) {
regs->ip = fixup->fixup;
return 1;
}
return 0;
}
#ifdef CONFIG_X86_64
/*
* Need to defined our own search_extable on X86_64 to work around
* a B stepping K8 bug.
*/
const struct exception_table_entry *
search_extable(const struct exception_table_entry *first,
const struct exception_table_entry *last,
unsigned long value)
{
/* B stepping K8 bug */
if ((value >> 32) == 0)
value |= 0xffffffffUL << 32;
while (first <= last) {
const struct exception_table_entry *mid;
long diff;
mid = (last - first) / 2 + first;
diff = mid->insn - value;
if (diff == 0)
return mid;
else if (diff < 0)
first = mid+1;
else
last = mid-1;
}
return NULL;
}
#endif

35
arch/x86/mm/extable_32.c
View file

@ -1,35 +0,0 @@
/*
* linux/arch/i386/mm/extable.c
*/
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
int fixup_exception(struct pt_regs *regs)
{
const struct exception_table_entry *fixup;
#ifdef CONFIG_PNPBIOS
if (unlikely(SEGMENT_IS_PNP_CODE(regs->cs)))
{
extern u32 pnp_bios_fault_eip, pnp_bios_fault_esp;
extern u32 pnp_bios_is_utter_crap;
pnp_bios_is_utter_crap = 1;
printk(KERN_CRIT "PNPBIOS fault.. attempting recovery.\n");
__asm__ volatile(
"movl %0, %%esp\n\t"
"jmp *%1\n\t"
: : "g" (pnp_bios_fault_esp), "g" (pnp_bios_fault_eip));
panic("do_trap: can't hit this");
}
#endif
fixup = search_exception_tables(regs->ip);
if (fixup) {
regs->ip = fixup->fixup;
return 1;
}
return 0;
}

34
arch/x86/mm/extable_64.c
View file

@ -1,34 +0,0 @@
/*
* linux/arch/x86_64/mm/extable.c
*/
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <asm/uaccess.h>
/* Simple binary search */
const struct exception_table_entry *
search_extable(const struct exception_table_entry *first,
const struct exception_table_entry *last,
unsigned long value)
{
/* Work around a B stepping K8 bug */
if ((value >> 32) == 0)
value |= 0xffffffffUL << 32;
while (first <= last) {
const struct exception_table_entry *mid;
long diff;
mid = (last - first) / 2 + first;
diff = mid->insn - value;
if (diff == 0)
return mid;
else if (diff < 0)
first = mid+1;
else
last = mid-1;
}
return NULL;
}