powerpc: Fix dedotify for binutils >= 2.26

[ Upstream commit f15838e9cac8f78f0cc506529bb9d3b9fa589c1f ]

Since binutils 2.26 BFD is doing suffix merging on STRTAB sections.  But
dedotify modifies the symbol names in place, which can also modify
unrelated symbols with a name that matches a suffix of a dotted name.  To
remove the leading dot of a symbol name we can just increment the pointer
into the STRTAB section instead.

Backport to all stables to avoid breakage when people update their
binutils - mpe.

Cc: stable@vger.kernel.org
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 59663af9315fc16123cd4aacb090a6efd8cbc33d..e4f7d4eed20ce7227a19e63336ac6de9c5f4cfec 100644 (file)
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -335,7 +335,7 @@ static void dedotify(Elf64_Sym *syms, unsigned int numsyms, char *strtab)
                if (syms[i].st_shndx == SHN_UNDEF) {
                        char *name = strtab + syms[i].st_name;
                        if (name[0] == '.')
-                               memmove(name, name+1, strlen(name));
+                               syms[i].st_name++;
                }
        }
 }