fix dynamic linker regression processing R_*_NONE type relocations

commit f3ddd173806fd5c60b3f034528ca24542aecc5b9 inadvertently removed
the early check for "none" type relocations, causing the address
dso->base+0 to be dereferenced to obtain an addend. shared libraries,
(including libc.so) and PIE executables were unaffected, since their
base addresses are the actual address of their mappings and are
readable. non-PIE main executables, however, have a base address of 0
because their load addresses are absolute and not offset at load time.

in practice none-type relocations do not arise with toolchains that
are in use except on mips, and on mips it's moderately rare for a
non-PIE executable to have a relocation table, since the mips-specific
got processing serves in its place for most purposes.

diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index 42930adfb44a6a46772addcedd0ad147402c9fdf..42b056d2f264aef11978ebf5ebeb8e48523dde69 100644 (file)
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -270,6 +270,7 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
        for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
                if (skip_relative && IS_RELATIVE(rel[1])) continue;
                type = R_TYPE(rel[1]);
+               if (type == REL_NONE) continue;
                sym_index = R_SYM(rel[1]);
                reloc_addr = (void *)(base + rel[0]);
                if (sym_index) {