Add bounds check to __libc_ifunc_impl_list

Add a proper bounds check to __libc_ifunc_impl_list. This makes MAX_IFUNC
redundant and fixes several targets that will write outside the array.
To avoid unnecessary large diffs, pass the maximum in the argument 'i' to
IFUNC_IMPL_ADD - 'max' can be used in new ifunc definitions and existing
ones can be updated if desired.

Passes buildmanyglibc.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

2 files changed, 4 insertions, 14 deletions

diff --git a/sysdeps/powerpc/powerpc32/power4/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc32/power4/multiarch/ifunc-impl-list.c
index 01890367a4..e6ef5e6267 100644
--- a/sysdeps/powerpc/powerpc32/power4/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc32/power4/multiarch/ifunc-impl-list.c
@@ -22,16 +22,11 @@
 #include <ldsodefs.h>
 #include <ifunc-impl-list.h>
 
-/* Maximum number of IFUNC implementations.  */
-#define MAX_IFUNC	6
-
 size_t
 __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 			size_t max)
 {
-  assert (max >= MAX_IFUNC);
-
-  size_t i = 0;
+  size_t i = max;
 
   unsigned long int hwcap = GLRO(dl_hwcap);
   /* hwcap contains only the latest supported ISA, the code checks which is
@@ -179,5 +174,5 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 	      IFUNC_IMPL_ADD (array, i, strchr, 1,
 			      __strchr_ppc))
 
-  return i;
+  return 0;
 }
diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
index ac533a9886..5a3c7a5886 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -22,16 +22,11 @@
 #include <ldsodefs.h>
 #include <ifunc-impl-list.h>
 
-/* Maximum number of IFUNC implementations.  */
-#define MAX_IFUNC	6
-
 size_t
 __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 			size_t max)
 {
-  assert (max >= MAX_IFUNC);
-
-  size_t i = 0;
+  size_t i = max;
 
   unsigned long int hwcap = GLRO(dl_hwcap);
   unsigned long int hwcap2 = GLRO(dl_hwcap2);
@@ -448,5 +443,5 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
              IFUNC_IMPL_ADD (array, i, strcasestr, 1,
                              __strcasestr_ppc))
 
-  return i;
+  return 0;
 }