On 03.01.2016 17:05, Ard Biesheuvel wrote: > This adds support to the generic search_extable() and sort_extable() > implementations for dealing with exception table entries whose fields > contain relative offsets rather than absolute addresses. > > Signed-off-by: Ard Biesheuvel <[email protected]>
I tested the generic parts with an upcoming patch which handles relative exception tables on the parisc platform. Everything worked as expected. So for the non arch-relevant changes: Acked-by: Helge Deller <[email protected]> Helge > --- > lib/extable.c | 50 ++++++++++++++++---- > 1 file changed, 41 insertions(+), 9 deletions(-) > > diff --git a/lib/extable.c b/lib/extable.c > index 4cac81ec225e..0be02ad561e9 100644 > --- a/lib/extable.c > +++ b/lib/extable.c > @@ -14,7 +14,37 @@ > #include <linux/sort.h> > #include <asm/uaccess.h> > > +#ifndef ARCH_HAS_RELATIVE_EXTABLE > +#define ex_to_insn(x) ((x)->insn) > +#else > +static inline unsigned long ex_to_insn(const struct exception_table_entry *x) > +{ > + return (unsigned long)&x->insn + x->insn; > +} > +#endif > + > #ifndef ARCH_HAS_SORT_EXTABLE > +#ifndef ARCH_HAS_RELATIVE_EXTABLE > +#define swap_ex NULL > +#else > +static void swap_ex(void *a, void *b, int size) > +{ > + struct exception_table_entry *x = a, *y = b, tmp; > + int delta = b - a; > + > + tmp = *x; > + x->insn = y->insn + delta; > + y->insn = tmp.insn - delta; > + > +#ifdef swap_ex_entry_fixup > + swap_ex_entry_fixup(x, y, tmp, delta); > +#else > + x->fixup = y->fixup + delta; > + y->fixup = tmp.fixup - delta; > +#endif > +} > +#endif /* ARCH_HAS_RELATIVE_EXTABLE */ > + > /* > * The exception table needs to be sorted so that the binary > * search that we use to find entries in it works properly. > @@ -26,9 +56,9 @@ static int cmp_ex(const void *a, const void *b) > const struct exception_table_entry *x = a, *y = b; > > /* avoid overflow */ > - if (x->insn > y->insn) > + if (ex_to_insn(x) > ex_to_insn(y)) > return 1; > - if (x->insn < y->insn) > + if (ex_to_insn(x) < ex_to_insn(y)) > return -1; > return 0; > } > @@ -37,7 +67,7 @@ void sort_extable(struct exception_table_entry *start, > struct exception_table_entry *finish) > { > sort(start, finish - start, sizeof(struct exception_table_entry), > - cmp_ex, NULL); > + cmp_ex, swap_ex); > } > > #ifdef CONFIG_MODULES > @@ -48,13 +78,15 @@ void sort_extable(struct exception_table_entry *start, > void trim_init_extable(struct module *m) > { > /*trim the beginning*/ > - while (m->num_exentries && within_module_init(m->extable[0].insn, m)) { > + while (m->num_exentries && > + within_module_init(ex_to_insn(&m->extable[0]), m)) { > m->extable++; > m->num_exentries--; > } > /*trim the end*/ > while (m->num_exentries && > - within_module_init(m->extable[m->num_exentries-1].insn, m)) > + within_module_init(ex_to_insn(&m->extable[m->num_exentries - 1]), > + m)) > m->num_exentries--; > } > #endif /* CONFIG_MODULES */ > @@ -81,13 +113,13 @@ search_extable(const struct exception_table_entry *first, > * careful, the distance between value and insn > * can be larger than MAX_LONG: > */ > - if (mid->insn < value) > + if (ex_to_insn(mid) < value) > first = mid + 1; > - else if (mid->insn > value) > + else if (ex_to_insn(mid) > value) > last = mid - 1; > else > return mid; > - } > - return NULL; > + } > + return NULL; > } > #endif > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
