#include <linux/module.h>
-#include <linux/spinlock.h>
-#include <linux/sort.h>
#include <asm/uaccess.h>
+#include <asm/traps.h>
typedef bool (*ex_handler_t)(const struct exception_table_entry *,
struct pt_regs *, int);
-static inline unsigned long
-ex_insn_addr(const struct exception_table_entry *x)
-{
- return (unsigned long)&x->insn + x->insn;
-}
static inline unsigned long
ex_fixup_addr(const struct exception_table_entry *x)
{
return handler(e, regs, trapnr);
}
+extern unsigned int early_recursion_flag;
+
/* Restricted version used during very early boot */
-int __init early_fixup_exception(unsigned long *ip)
+void __init early_fixup_exception(struct pt_regs *regs, int trapnr)
{
- const struct exception_table_entry *e;
- unsigned long new_ip;
- ex_handler_t handler;
-
- e = search_exception_tables(*ip);
- if (!e)
- return 0;
-
- new_ip = ex_fixup_addr(e);
- handler = ex_fixup_handler(e);
-
- /* special handling not supported during early boot */
- if (handler != ex_handler_default)
- return 0;
+ /* Ignore early NMIs. */
+ if (trapnr == X86_TRAP_NMI)
+ return;
- *ip = new_ip;
- return 1;
-}
+ if (early_recursion_flag > 2)
+ goto halt_loop;
-/*
- * Search one exception table for an entry corresponding to the
- * given instruction address, and return the address of the entry,
- * or NULL if none is found.
- * We use a binary search, and thus we assume that the table is
- * already sorted.
- */
-const struct exception_table_entry *
-search_extable(const struct exception_table_entry *first,
- const struct exception_table_entry *last,
- unsigned long value)
-{
- while (first <= last) {
- const struct exception_table_entry *mid;
- unsigned long addr;
-
- mid = ((last - first) >> 1) + first;
- addr = ex_insn_addr(mid);
- if (addr < value)
- first = mid + 1;
- else if (addr > value)
- last = mid - 1;
- else
- return mid;
- }
- return NULL;
-}
+ if (regs->cs != __KERNEL_CS)
+ goto fail;
-/*
- * The exception table needs to be sorted so that the binary
- * search that we use to find entries in it works properly.
- * This is used both for the kernel exception table and for
- * the exception tables of modules that get loaded.
- *
- */
-static int cmp_ex(const void *a, const void *b)
-{
- const struct exception_table_entry *x = a, *y = b;
-
- /*
- * This value will always end up fittin in an int, because on
- * both i386 and x86-64 the kernel symbol-reachable address
- * space is < 2 GiB.
- *
- * This compare is only valid after normalization.
- */
- return x->insn - y->insn;
-}
+ if (fixup_exception(regs, trapnr))
+ return;
-void sort_extable(struct exception_table_entry *start,
- struct exception_table_entry *finish)
-{
- struct exception_table_entry *p;
- int i;
-
- /* Convert all entries to being relative to the start of the section */
- i = 0;
- for (p = start; p < finish; p++) {
- p->insn += i;
- i += 4;
- p->fixup += i;
- i += 4;
- p->handler += i;
- i += 4;
- }
+fail:
+ early_printk("PANIC: early exception 0x%02x IP %lx:%lx error %lx cr2 0x%lx\n",
+ (unsigned)trapnr, (unsigned long)regs->cs, regs->ip,
+ regs->orig_ax, read_cr2());
- sort(start, finish - start, sizeof(struct exception_table_entry),
- cmp_ex, NULL);
-
- /* Denormalize all entries */
- i = 0;
- for (p = start; p < finish; p++) {
- p->insn -= i;
- i += 4;
- p->fixup -= i;
- i += 4;
- p->handler -= i;
- i += 4;
- }
-}
+ show_regs(regs);
-#ifdef CONFIG_MODULES
-/*
- * If the exception table is sorted, any referring to the module init
- * will be at the beginning or the end.
- */
-void trim_init_extable(struct module *m)
-{
- /*trim the beginning*/
- while (m->num_exentries &&
- within_module_init(ex_insn_addr(&m->extable[0]), m)) {
- m->extable++;
- m->num_exentries--;
- }
- /*trim the end*/
- while (m->num_exentries &&
- within_module_init(ex_insn_addr(&m->extable[m->num_exentries-1]), m))
- m->num_exentries--;
+halt_loop:
+ while (true)
+ halt();
}
-#endif /* CONFIG_MODULES */