x86/extable: use generic search and sort routines
Replace the arch specific versions of search_extable() and sort_extable() with calls to the generic ones, which now support relative exception tables as well. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ard Biesheuvel
Linus Torvalds
parent
c352e8b6de
commit
29934b0fb8
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@ -105,9 +105,8 @@ static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, un
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struct exception_table_entry {
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struct exception_table_entry {
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int insn, fixup, handler;
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int insn, fixup, handler;
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};
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};
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/* This is not the generic standard exception_table_entry format */
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#define ARCH_HAS_SORT_EXTABLE
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#define ARCH_HAS_RELATIVE_EXTABLE
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#define ARCH_HAS_SEARCH_EXTABLE
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extern int fixup_exception(struct pt_regs *regs, int trapnr);
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extern int fixup_exception(struct pt_regs *regs, int trapnr);
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extern bool ex_has_fault_handler(unsigned long ip);
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extern bool ex_has_fault_handler(unsigned long ip);
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@ -1,16 +1,9 @@
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#include <linux/module.h>
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#include <linux/module.h>
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#include <linux/spinlock.h>
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#include <linux/sort.h>
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#include <asm/uaccess.h>
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#include <asm/uaccess.h>
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typedef bool (*ex_handler_t)(const struct exception_table_entry *,
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typedef bool (*ex_handler_t)(const struct exception_table_entry *,
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struct pt_regs *, int);
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struct pt_regs *, int);
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static inline unsigned long
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ex_insn_addr(const struct exception_table_entry *x)
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{
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return (unsigned long)&x->insn + x->insn;
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}
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static inline unsigned long
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static inline unsigned long
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ex_fixup_addr(const struct exception_table_entry *x)
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ex_fixup_addr(const struct exception_table_entry *x)
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{
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{
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@ -110,104 +103,3 @@ int __init early_fixup_exception(unsigned long *ip)
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*ip = new_ip;
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*ip = new_ip;
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return 1;
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return 1;
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}
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}
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/*
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* Search one exception table for an entry corresponding to the
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* given instruction address, and return the address of the entry,
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* or NULL if none is found.
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* We use a binary search, and thus we assume that the table is
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* already sorted.
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*/
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const struct exception_table_entry *
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search_extable(const struct exception_table_entry *first,
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const struct exception_table_entry *last,
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unsigned long value)
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{
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while (first <= last) {
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const struct exception_table_entry *mid;
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unsigned long addr;
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mid = ((last - first) >> 1) + first;
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addr = ex_insn_addr(mid);
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if (addr < value)
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first = mid + 1;
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else if (addr > value)
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last = mid - 1;
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else
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return mid;
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}
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return NULL;
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}
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/*
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* The exception table needs to be sorted so that the binary
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* search that we use to find entries in it works properly.
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* This is used both for the kernel exception table and for
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* the exception tables of modules that get loaded.
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*
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*/
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static int cmp_ex(const void *a, const void *b)
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{
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const struct exception_table_entry *x = a, *y = b;
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/*
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* This value will always end up fittin in an int, because on
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* both i386 and x86-64 the kernel symbol-reachable address
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* space is < 2 GiB.
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*
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* This compare is only valid after normalization.
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*/
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return x->insn - y->insn;
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}
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void sort_extable(struct exception_table_entry *start,
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struct exception_table_entry *finish)
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{
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struct exception_table_entry *p;
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int i;
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/* Convert all entries to being relative to the start of the section */
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i = 0;
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for (p = start; p < finish; p++) {
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p->insn += i;
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i += 4;
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p->fixup += i;
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i += 4;
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p->handler += i;
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i += 4;
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}
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sort(start, finish - start, sizeof(struct exception_table_entry),
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cmp_ex, NULL);
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/* Denormalize all entries */
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i = 0;
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for (p = start; p < finish; p++) {
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p->insn -= i;
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i += 4;
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p->fixup -= i;
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i += 4;
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p->handler -= i;
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i += 4;
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}
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}
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#ifdef CONFIG_MODULES
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/*
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* If the exception table is sorted, any referring to the module init
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* will be at the beginning or the end.
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*/
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void trim_init_extable(struct module *m)
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{
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/*trim the beginning*/
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while (m->num_exentries &&
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within_module_init(ex_insn_addr(&m->extable[0]), m)) {
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m->extable++;
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m->num_exentries--;
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}
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/*trim the end*/
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while (m->num_exentries &&
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within_module_init(ex_insn_addr(&m->extable[m->num_exentries-1]), m))
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m->num_exentries--;
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}
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#endif /* CONFIG_MODULES */
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